/* ============================================================
   Grammar Quest - 语法冒险
   A kid-friendly, Duolingo-inspired English grammar learning app
   ============================================================ */

/* ----- CSS Custom Properties ----- */
:root {
  /* Core palette */
  --color-primary: #58CC02;
  --color-primary-dark: #46A302;
  --color-primary-light: #8EE000;
  --color-secondary: #1CB0F6;
  --color-secondary-dark: #1899D6;
  --color-secondary-light: #84D8FF;
  --color-danger: #FF4B4B;
  --color-danger-dark: #EA2B2B;
  --color-warning: #FFC800;
  --color-warning-dark: #E5B400;
  --color-warning-light: #FFE066;

  /* Surfaces */
  --color-bg: #F7F7F7;
  --color-card: #FFFFFF;
  --color-text: #3C3C3C;
  --color-text-light: #777777;
  --color-muted: #AFAFAF;
  --color-border: #E5E5E5;
  --color-overlay: rgba(0, 0, 0, 0.45);

  /* Rank colors */
  --rank-bronze: #CD7F32;
  --rank-silver: #C0C0C0;
  --rank-gold: #FFD700;
  --rank-diamond: #B9F2FF;
  --rank-diamond-stroke: #7DD8EF;
  --rank-master: #FF6B6B;

  /* Spacing */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;

  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", "Noto Sans SC", "Source Han Sans SC", "Helvetica Neue",
    Arial, sans-serif;
  --font-mono: "SF Mono", "Fira Code", "Noto Sans Mono CJK SC", monospace;
  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 2rem;

  /* Radii */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);
  --shadow-btn: 0 4px 0;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 400ms ease;

  /* Layout */
  --nav-height: 64px;
  --tab-height: 60px;
  --max-width: 480px;
  --sidebar-width: 240px;
  --content-width: 1080px;
}

/* ----- Reset & Base ----- */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
  -webkit-tap-highlight-color: transparent;
}

body {
  font-family: var(--font-sans);
  color: var(--color-text);
  background-color: var(--color-bg);
  line-height: 1.5;
  min-height: 100dvh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

#app {
  width: 100%;
  min-height: 100dvh;
  position: relative;
  background: var(--color-bg);
}

/* ============================================================
   DESKTOP LAYOUT: left sidebar + main column
   ============================================================ */
.layout {
  display: flex;
  min-height: 100dvh;
  align-items: stretch;
}

.sidebar {
  flex: 0 0 var(--sidebar-width);
  width: var(--sidebar-width);
  position: sticky;
  top: 0;
  align-self: flex-start;
  height: 100dvh;
  background: var(--color-card);
  border-right: 2px solid var(--color-border);
  display: flex;
  flex-direction: column;
  padding: var(--space-lg) var(--space-md);
  z-index: 50;
}

.sidebar__brand {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-sm) var(--space-lg);
  border-bottom: 1px solid var(--color-border);
  margin-bottom: var(--space-md);
}
.sidebar__brand-logo {
  font-size: 1.9rem;
  line-height: 1;
}
.sidebar__brand-text {
  display: flex;
  flex-direction: column;
  font-weight: 800;
  font-size: var(--text-lg);
  color: var(--color-text);
  line-height: 1.2;
}
.sidebar__brand-text small {
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-muted);
}

/* 不用 flex:1 撑满：侧边栏本来就比内容高，撑满会把账号面板顶到最底，
   在菜单和账号之间留下一段空白。菜单和账号挨着排，多余的高度落在最下面。 */
.sidebar__nav {
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
  flex: 0 0 auto;
}

.sidebar__item {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-md);
  border-radius: var(--radius-md);
  font-size: var(--text-base);
  font-weight: 700;
  color: var(--color-text-light);
  text-align: left;
  transition: background var(--transition-fast), color var(--transition-fast);
}
.sidebar__item:hover {
  background: var(--color-bg);
}
.sidebar__item.active {
  background: rgba(28, 176, 246, 0.12);
  color: var(--color-secondary);
}
.sidebar__item-icon {
  font-size: 1.4rem;
  line-height: 1;
}

.sidebar__footer {
  border-top: 1px solid var(--color-border);
  padding-top: var(--space-md);
  margin-top: var(--space-sm);
}
/* Account panel: name + view-link (clickable) with the stats grouped
   beneath as smaller sub-info, so it all reads as one account block. */
.sidebar__account-panel {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-bg);
  overflow: hidden;
}
/* 账号名是家长的（用家长邮箱注册）。加一行小字点明这一点，
   否则和下面的段位/积分挨在一起，会读成"这些积分是这个账号的人挣的"。 */
.sidebar__account-role {
  display: block;
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-muted);
  margin-top: 2px;
}
.sidebar__stats {
  display: flex;
  flex-direction: column;
  gap: 3px;
  padding: var(--space-sm) var(--space-md);
  border-top: 1px solid var(--color-border);
  font-size: var(--text-xs);
  font-weight: 600;
}
.sidebar__stat--rank { color: var(--color-text); }
.sidebar__stat--score { color: var(--color-warning); }
.sidebar__stat--streak { color: var(--color-text-light); }

.main-col {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 40;
  display: flex;
  align-items: center;
  gap: var(--space-md);
  height: var(--nav-height);
  padding: 0 var(--space-xl);
  background: var(--color-card);
  border-bottom: 2px solid var(--color-border);
}
.topbar__back {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: var(--space-xs) var(--space-md);
  border-radius: var(--radius-full);
  font-size: var(--text-sm);
  font-weight: 700;
  color: var(--color-secondary);
  transition: background var(--transition-fast);
}
.topbar__back:hover { background: var(--color-bg); }
.topbar__back-placeholder { width: 1px; }
.topbar__title {
  font-size: var(--text-lg);
  font-weight: 800;
}
.topbar__spacer { flex: 1; }

/* 顶层页面（学习地图、复习中心…）没有返回按钮，页面带里就只剩一个标题。
   宽屏上左轨已经高亮了当前所在的位置，再为一个词撑起一整条白带是浪费，
   看起来也像一条空横梁。窄屏保留：那里导航只有图标、没有文字标签，
   页面名是唯一能说明"我在哪"的东西。 */
@media (min-width: 721px) {
  .topbar--title-only { display: none; }
}

.content {
  flex: 1;
  width: 100%;
  max-width: var(--content-width);
  margin: 0 auto;
  padding: var(--space-xl);
}

img, svg {
  display: block;
  max-width: 100%;
}

button, input, textarea {
  font: inherit;
  color: inherit;
  border: none;
  background: none;
  outline: none;
}

button {
  cursor: pointer;
  -webkit-user-select: none;
  user-select: none;
}

a {
  color: inherit;
  text-decoration: none;
}

ul, ol {
  list-style: none;
}

/* ----- Scrollbar (subtle) ----- */
::-webkit-scrollbar {
  width: 4px;
}
::-webkit-scrollbar-thumb {
  background: var(--color-muted);
  border-radius: var(--radius-full);
}

/* ============================================================
   TOP NAV BAR
   ============================================================ */
.nav-bar {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--nav-height);
  padding: 0 var(--space-md);
  background: var(--color-card);
  border-bottom: 2px solid var(--color-border);
}

.nav-bar__back {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-full);
  font-size: var(--text-xl);
  transition: background var(--transition-fast);
}
.nav-bar__back:hover {
  background: var(--color-bg);
}

.nav-bar__title {
  font-size: var(--text-lg);
  font-weight: 700;
  flex: 1;
  text-align: center;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.nav-bar__right {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.nav-bar__score {
  font-weight: 700;
  color: var(--color-warning);
  font-size: var(--text-sm);
  display: flex;
  align-items: center;
  gap: 2px;
}

/* ============================================================
   BOTTOM TAB BAR
   ============================================================ */
.tab-bar {
  position: fixed;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 100%;
  max-width: var(--max-width);
  height: var(--tab-height);
  display: flex;
  align-items: stretch;
  background: var(--color-card);
  border-top: 2px solid var(--color-border);
  z-index: 100;
  padding-bottom: env(safe-area-inset-bottom, 0);
}

.tab-bar__item {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 2px;
  font-size: var(--text-xs);
  color: var(--color-muted);
  transition: color var(--transition-fast);
  position: relative;
}
.tab-bar__item::before {
  content: "";
  position: absolute;
  top: 0;
  left: 25%;
  right: 25%;
  height: 3px;
  border-radius: 0 0 3px 3px;
  background: transparent;
  transition: background var(--transition-fast);
}

.tab-bar__item.active {
  color: var(--color-secondary);
  font-weight: 700;
}
.tab-bar__item.active::before {
  background: var(--color-secondary);
}

.tab-bar__icon {
  font-size: 1.4rem;
  line-height: 1;
}

.tab-bar__label {
  line-height: 1;
}

.view {
  animation: fadeIn var(--transition-base);
}

/* ============================================================
   ENERGY / HEARTS DISPLAY
   ============================================================ */
.energy-bar {
  display: flex;
  align-items: center;
  gap: 2px;
}

.energy-bar__heart {
  font-size: var(--text-lg);
  transition: transform var(--transition-fast);
}
.energy-bar__heart--lost {
  opacity: 0.25;
  filter: grayscale(1);
  animation: heartBreak 0.5s ease;
}
.energy-bar__heart--breaking {
  animation: heartBreak 0.5s ease forwards;
}

/* ============================================================
   HOME / MAP VIEW
   ============================================================ */
.view-map {
  padding: var(--space-md);
}

/* Player stats bar */
.player-stats {
  display: flex;
  align-items: center;
  justify-content: space-around;
  background: var(--color-card);
  border-radius: var(--radius-lg);
  padding: var(--space-md);
  margin-bottom: var(--space-lg);
  box-shadow: var(--shadow-sm);
}

.player-stats__item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-xs);
}

.player-stats__value {
  font-weight: 800;
  font-size: var(--text-xl);
  color: var(--color-text);
}

.player-stats__label {
  font-size: var(--text-xs);
  color: var(--color-muted);
}

/* Unit grid (desktop map) */
.unit-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(190px, 1fr));
  gap: var(--space-lg);
  padding: var(--space-md) 0 var(--space-2xl);
}

/* Unit node = card */
.unit-node {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-lg) var(--space-md);
  background: var(--color-card);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  cursor: pointer;
  transition: transform var(--transition-fast), box-shadow var(--transition-base), border-color var(--transition-base);
}
.unit-node:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-secondary);
}
.unit-node:active {
  transform: scale(0.98);
}

.unit-node__no {
  font-size: var(--text-xs);
  font-weight: 700;
  color: var(--color-muted);
  letter-spacing: 0.5px;
}
.unit-node__status {
  font-size: var(--text-xs);
  color: var(--color-muted);
}
.unit-node--available .unit-node__status,
.unit-node--available .unit-node__no { color: var(--color-secondary); }

.unit-node__circle {
  width: 72px;
  height: 72px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-2xl);
  font-weight: 800;
  color: #fff;
  position: relative;
  transition: box-shadow var(--transition-base), transform var(--transition-base);
}

/* Progress ring around node */
.unit-node__circle::after {
  content: "";
  position: absolute;
  inset: -5px;
  border-radius: 50%;
  border: 4px solid transparent;
  transition: border-color var(--transition-base);
}

/* States */
.unit-node--locked .unit-node__circle {
  background: var(--color-muted);
  box-shadow: var(--shadow-btn) #999;
}
.unit-node--locked {
  opacity: 0.5;
  cursor: not-allowed;
  pointer-events: none;
}

.unit-node--available .unit-node__circle {
  background: var(--color-secondary);
  box-shadow: var(--shadow-btn) var(--color-secondary-dark);
}

.unit-node--in-progress .unit-node__circle {
  background: var(--color-primary);
  box-shadow: var(--shadow-btn) var(--color-primary-dark);
  animation: pulse 2s ease-in-out infinite;
}
.unit-node--in-progress .unit-node__circle::after {
  border-color: var(--color-primary-light);
  animation: pulse 2s ease-in-out infinite;
}

.unit-node--completed .unit-node__circle {
  background: var(--color-warning);
  box-shadow: var(--shadow-btn) var(--color-warning-dark);
}

.unit-node__name {
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-text);
  text-align: center;
  max-width: 120px;
}

.unit-node__stars {
  display: flex;
  gap: 2px;
  font-size: var(--text-sm);
}
.unit-node__stars .star--empty {
  opacity: 0.3;
}

.unit-node__lock-icon {
  font-size: var(--text-xl);
}

/* ============================================================
   UNIT DETAIL VIEW
   ============================================================ */
.view-unit {
  padding: var(--space-md);
}

.unit-header {
  text-align: center;
  margin-bottom: var(--space-lg);
}
.unit-header__title {
  font-size: var(--text-2xl);
  font-weight: 800;
}
.unit-header__subtitle {
  color: var(--color-text-light);
  font-size: var(--text-sm);
  margin-top: var(--space-xs);
}

.phase-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.phase-card {
  background: var(--color-card);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  box-shadow: var(--shadow-sm);
  display: flex;
  align-items: center;
  gap: var(--space-md);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
  cursor: pointer;
  border-left: 5px solid transparent;
}
.phase-card:active {
  transform: scale(0.98);
}

.phase-card--discover {
  border-left-color: var(--color-secondary);
}
.phase-card--practice {
  border-left-color: var(--color-primary);
}
.phase-card--mission {
  border-left-color: var(--color-warning);
}

.phase-card--locked {
  opacity: 0.45;
  pointer-events: none;
  filter: grayscale(0.5);
}

.phase-card__icon {
  font-size: 2rem;
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-bg);
  border-radius: var(--radius-md);
  flex-shrink: 0;
}

.phase-card__info {
  flex: 1;
  min-width: 0;
}

.phase-card__title {
  font-weight: 700;
  font-size: var(--text-base);
}

.phase-card__desc {
  font-size: var(--text-sm);
  color: var(--color-text-light);
  margin-top: 2px;
}

.phase-card__progress {
  margin-top: var(--space-sm);
}

.phase-card__chevron {
  font-size: var(--text-xl);
  color: var(--color-muted);
}

/* ============================================================
   PRACTICE VIEW
   ============================================================ */
.view-practice {
  padding: 0;
  padding-bottom: calc(var(--tab-height) + var(--space-md));
  display: flex;
  flex-direction: column;
  min-height: 100dvh;
}

/* Practice header */
.practice-header {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-md);
  background: var(--color-card);
  border-bottom: 2px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 50;
}

.practice-header__close {
  font-size: var(--text-xl);
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.practice-header__progress {
  flex: 1;
}

.practice-header__score {
  font-weight: 700;
  color: var(--color-warning);
  font-size: var(--text-sm);
  min-width: 50px;
  text-align: right;
}

/* Question area */
.question-area {
  flex: 1;
  padding: var(--space-lg) var(--space-md);
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
}

.question-prompt {
  font-size: var(--text-xl);
  font-weight: 700;
  line-height: 1.6;
}

.question-instruction {
  font-size: var(--text-sm);
  color: var(--color-text-light);
  margin-bottom: var(--space-sm);
}

.question-sentence {
  font-size: var(--text-lg);
  line-height: 1.8;
  padding: var(--space-md);
  background: var(--color-card);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
}

.question-sentence .blank {
  display: inline-block;
  min-width: 80px;
  border-bottom: 3px solid var(--color-secondary);
  text-align: center;
  margin: 0 var(--space-xs);
  padding: 0 var(--space-sm);
  color: var(--color-secondary);
  font-weight: 700;
}

/* Choice questions - 2x2 grid */
.choices-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-sm);
}

.choice-btn {
  padding: var(--space-md);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-card);
  font-size: var(--text-base);
  font-weight: 600;
  text-align: center;
  transition: all var(--transition-fast);
  box-shadow: var(--shadow-btn) var(--color-border);
  position: relative;
}
.choice-btn:active {
  transform: translateY(2px);
  box-shadow: 0 2px 0 var(--color-border);
}

.choice-btn--selected {
  border-color: var(--color-secondary);
  background: rgba(28, 176, 246, 0.08);
  color: var(--color-secondary);
  box-shadow: var(--shadow-btn) var(--color-secondary-dark);
}

.choice-btn--correct {
  border-color: var(--color-primary);
  background: rgba(88, 204, 2, 0.1);
  color: var(--color-primary-dark);
  box-shadow: var(--shadow-btn) var(--color-primary-dark);
  animation: bounce 0.4s ease;
}

.choice-btn--wrong {
  border-color: var(--color-danger);
  background: rgba(255, 75, 75, 0.1);
  color: var(--color-danger);
  animation: shake 0.4s ease;
  box-shadow: var(--shadow-btn) var(--color-danger-dark);
}

/* Reorder questions - word chips */
.word-bank {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  padding: var(--space-md);
  background: var(--color-card);
  border-radius: var(--radius-md);
  min-height: 56px;
  border: 2px dashed var(--color-border);
}

.answer-area {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  padding: var(--space-md);
  background: rgba(28, 176, 246, 0.05);
  border-radius: var(--radius-md);
  min-height: 56px;
  border: 2px solid var(--color-secondary);
}

.word-chip {
  padding: var(--space-sm) var(--space-md);
  background: var(--color-card);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-size: var(--text-base);
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-fast);
  box-shadow: 0 2px 0 var(--color-border);
  user-select: none;
}
.word-chip:active {
  transform: translateY(2px);
  box-shadow: none;
}
.word-chip--placed {
  opacity: 0.3;
  pointer-events: none;
}
.word-chip--in-answer {
  background: var(--color-secondary);
  color: #fff;
  border-color: var(--color-secondary-dark);
  box-shadow: 0 2px 0 var(--color-secondary-dark);
}

/* Error-find questions - clickable segments */
.error-sentence {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-xs);
  padding: var(--space-md);
  font-size: var(--text-lg);
  line-height: 2;
}

.error-word {
  padding: var(--space-xs) var(--space-sm);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
  border: 2px solid transparent;
}
.error-word:hover {
  background: rgba(28, 176, 246, 0.08);
}
.error-word--selected {
  background: rgba(255, 75, 75, 0.12);
  border-color: var(--color-danger);
  color: var(--color-danger);
  font-weight: 700;
  text-decoration: line-through;
}
.error-word--correct-target {
  background: rgba(88, 204, 2, 0.12);
  border-color: var(--color-primary);
  color: var(--color-primary-dark);
  font-weight: 700;
}

/* Match questions - two columns */
.match-columns {
  display: flex;
  gap: var(--space-md);
  position: relative;
}

.match-lines {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 1;
}

.match-column {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.match-item {
  padding: var(--space-md);
  background: var(--color-card);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  font-weight: 600;
  text-align: center;
  cursor: pointer;
  transition: all var(--transition-fast);
}
.match-item--selected {
  border-color: var(--color-secondary);
  background: rgba(28, 176, 246, 0.08);
}
.match-item--matched {
  border-color: var(--color-primary);
  background: rgba(88, 204, 2, 0.08);
  cursor: pointer;
}
.match-item--wrong {
  animation: shake 0.4s ease;
  border-color: var(--color-danger);
}

/* Fill-in questions - inline input */
.fill-input {
  display: inline-block;
  border: none;
  border-bottom: 3px solid var(--color-secondary);
  background: rgba(28, 176, 246, 0.05);
  padding: var(--space-xs) var(--space-sm);
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--color-secondary);
  min-width: 100px;
  text-align: center;
  border-radius: 4px 4px 0 0;
  transition: border-color var(--transition-fast);
}
.fill-input:focus {
  border-color: var(--color-secondary-dark);
  background: rgba(28, 176, 246, 0.1);
}
.fill-input--correct {
  border-color: var(--color-primary);
  color: var(--color-primary-dark);
  background: rgba(88, 204, 2, 0.08);
}
.fill-input--wrong {
  border-color: var(--color-danger);
  color: var(--color-danger);
  background: rgba(255, 75, 75, 0.08);
}

/* Scenario questions - chat bubbles */
.chat-area {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  padding: var(--space-md);
}

.chat-bubble {
  max-width: 80%;
  padding: var(--space-md);
  border-radius: var(--radius-lg);
  font-size: var(--text-base);
  line-height: 1.5;
  animation: slideUp 0.3s ease;
}

.chat-bubble--npc {
  align-self: flex-start;
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-bottom-left-radius: var(--space-xs);
}

.chat-bubble--player {
  align-self: flex-end;
  background: var(--color-secondary);
  color: #fff;
  border-bottom-right-radius: var(--space-xs);
}

.chat-choices {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  padding: var(--space-sm);
}

.chat-choice-btn {
  padding: var(--space-md);
  background: var(--color-card);
  border: 2px solid var(--color-secondary);
  border-radius: var(--radius-xl);
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-secondary);
  text-align: left;
  transition: all var(--transition-fast);
}
.chat-choice-btn:active {
  background: rgba(28, 176, 246, 0.1);
}

/* Practice action bar (Check button) */
.practice-action {
  padding: var(--space-md);
  background: var(--color-card);
  border-top: 2px solid var(--color-border);
  position: sticky;
  bottom: 0;
}

/* ============================================================
   FEEDBACK OVERLAYS
   ============================================================ */
.feedback-banner {
  position: fixed;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 100%;
  max-width: var(--max-width);
  padding: var(--space-lg) var(--space-md);
  padding-bottom: calc(var(--space-lg) + env(safe-area-inset-bottom, 0));
  z-index: 200;
  animation: slideUp 0.3s ease;
}

.feedback-banner--correct {
  background: var(--color-primary);
  color: #fff;
}

.feedback-banner--wrong {
  background: var(--color-danger);
  color: #fff;
}

.feedback-banner__header {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: var(--text-xl);
  font-weight: 800;
  margin-bottom: var(--space-sm);
}

.feedback-banner__icon {
  font-size: var(--text-2xl);
}

.feedback-banner__explanation {
  font-size: var(--text-sm);
  opacity: 0.95;
  line-height: 1.6;
}

/* 一题多解时，把其余写法也列出来，别让学习者以为自己那种是错的 */
.feedback-banner__alt {
  margin-top: 6px;
  font-size: var(--text-xs);
  line-height: 1.7;
  opacity: 0.92;
}

.feedback-banner__correct-answer {
  margin-top: var(--space-sm);
  padding: var(--space-sm) var(--space-md);
  background: rgba(255, 255, 255, 0.2);
  border-radius: var(--radius-sm);
  font-weight: 600;
}

.feedback-banner .btn-primary {
  margin-top: var(--space-md);
  width: 100%;
}

/* Score float animation */
.score-float {
  position: fixed;
  font-size: var(--text-2xl);
  font-weight: 800;
  color: var(--color-warning);
  pointer-events: none;
  z-index: 300;
  animation: scoreFloat 1s ease forwards;
  text-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

@keyframes scoreFloat {
  0% { opacity: 1; transform: translateY(0) scale(1); }
  50% { opacity: 1; transform: translateY(-40px) scale(1.3); }
  100% { opacity: 0; transform: translateY(-80px) scale(1); }
}

/* Combo display */
.combo-display {
  position: fixed;
  top: 80px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 250;
  background: linear-gradient(135deg, #FFD700, #FF9600, #CE82FF);
  color: #fff;
  font-weight: 800;
  font-size: var(--text-xl);
  padding: var(--space-sm) var(--space-lg);
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  box-shadow: var(--shadow-lg);
  animation: comboFire 0.5s ease;
  pointer-events: none;
}

.combo-display__fire {
  animation: comboFireIcon 0.6s ease infinite alternate;
}

.combo-display--fire {
  background: linear-gradient(135deg, #FF6B00, #FF9600, #FFD700);
  font-size: var(--text-2xl);
}

.combo-display--hot {
  background: linear-gradient(135deg, #FF4500, #FF6B00, #FFD700);
  font-size: var(--text-2xl);
  box-shadow: 0 0 20px rgba(255, 69, 0, 0.5);
}

.combo-display--epic {
  background: linear-gradient(135deg, #9400D3, #CE82FF, #FFD700);
  font-size: 1.75rem;
  box-shadow: 0 0 30px rgba(148, 0, 211, 0.5);
}

.combo-display--legendary {
  background: linear-gradient(135deg, #FFD700, #FF4500, #9400D3, #FFD700);
  background-size: 300% 300%;
  animation: comboFire 0.5s ease, legendaryShimmer 1.5s ease infinite;
  font-size: 2rem;
  box-shadow: 0 0 40px rgba(255, 215, 0, 0.6);
}

@keyframes legendaryShimmer {
  0%, 100% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
}

@keyframes screenShake {
  0%, 100% { transform: translateX(0); }
  10%, 50%, 90% { transform: translateX(-3px); }
  30%, 70% { transform: translateX(3px); }
}

.screen-shake {
  animation: screenShake 0.3s ease;
}

.new-badges-banner {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  justify-content: center;
  margin: var(--space-md) 0;
  animation: badgePop 0.6s ease;
}

.new-badge-item {
  background: linear-gradient(135deg, #FFD700, #FF9600);
  color: #fff;
  font-weight: 700;
  font-size: var(--text-sm);
  padding: var(--space-xs) var(--space-md);
  border-radius: var(--radius-full);
  box-shadow: 0 2px 8px rgba(255, 150, 0, 0.3);
  white-space: nowrap;
}

@keyframes badgePop {
  0% { opacity: 0; transform: scale(0.5); }
  60% { transform: scale(1.1); }
  100% { opacity: 1; transform: scale(1); }
}

/* ============================================================
   MISSION VIEW
   ============================================================ */
.view-mission {
  padding: var(--space-md);
}

.mission-task-card {
  background: linear-gradient(135deg, var(--color-secondary), #5B8DEF);
  color: #fff;
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  margin-bottom: var(--space-lg);
  box-shadow: var(--shadow-md);
}

.mission-task-card__title {
  font-size: var(--text-xl);
  font-weight: 800;
  margin-bottom: var(--space-sm);
}

.mission-task-card__desc {
  font-size: var(--text-sm);
  opacity: 0.9;
  line-height: 1.6;
}

.writing-area {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.writing-line {
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

.writing-line__starter {
  font-size: var(--text-sm);
  color: var(--color-text-light);
  font-weight: 600;
}

.writing-line__fixed {
  font-size: var(--text-base);
  color: var(--color-text);
  font-weight: 600;
  padding: var(--space-sm) 0;
  border-bottom: 1px solid var(--color-border);
}

.writing-line__input {
  width: 100%;
  padding: var(--space-md);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: var(--text-base);
  line-height: 1.6;
  resize: vertical;
  min-height: 60px;
  transition: border-color var(--transition-fast);
}
.writing-line__input:focus {
  border-color: var(--color-secondary);
}

.writing-line__feedback {
  font-size: var(--text-sm);
  padding: var(--space-sm);
  border-radius: var(--radius-sm);
}
.writing-line__feedback--correct {
  background: rgba(88, 204, 2, 0.1);
  color: var(--color-primary-dark);
}
.writing-line__feedback--suggestion {
  background: rgba(28, 176, 246, 0.1);
  color: var(--color-secondary-dark);
}

/* Completion card */
.mission-complete-card {
  background: var(--color-card);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  box-shadow: var(--shadow-md);
  margin-top: var(--space-lg);
  border: 2px solid var(--color-primary);
}

.mission-complete-card__title {
  font-size: var(--text-lg);
  font-weight: 700;
  text-align: center;
  margin-bottom: var(--space-md);
}

.mission-complete-card__article {
  font-size: var(--text-base);
  line-height: 1.8;
  padding: var(--space-md);
  background: var(--color-bg);
  border-radius: var(--radius-md);
  border-left: 4px solid var(--color-primary);
}

/* ============================================================
   PORTFOLIO VIEW
   ============================================================ */
.view-portfolio {
  padding: var(--space-md);
}

.portfolio-counter {
  text-align: center;
  font-size: var(--text-sm);
  color: var(--color-text-light);
  margin-bottom: var(--space-lg);
  font-weight: 600;
}
.portfolio-counter strong {
  color: var(--color-primary);
  font-size: var(--text-lg);
}

.portfolio-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-md);
}

.portfolio-card {
  background: var(--color-card);
  border-radius: var(--radius-md);
  padding: var(--space-md);
  box-shadow: var(--shadow-sm);
  cursor: pointer;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  min-height: 140px;
}
.portfolio-card:active {
  transform: scale(0.97);
}

.portfolio-card__title {
  font-weight: 700;
  font-size: var(--text-sm);
  line-height: 1.4;
}

.portfolio-card__date {
  font-size: var(--text-xs);
  color: var(--color-muted);
}

.portfolio-card__preview {
  font-size: var(--text-xs);
  color: var(--color-text-light);
  line-height: 1.5;
  flex: 1;
  overflow: hidden;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
}

.portfolio-card--locked {
  opacity: 0.4;
  background: var(--color-bg);
  pointer-events: none;
  border: 2px dashed var(--color-border);
}
.portfolio-card--locked .portfolio-card__title {
  color: var(--color-muted);
}

/* ============================================================
   STATS VIEW
   ============================================================ */
.view-stats {
  padding: var(--space-md);
}

/* Rank badge */
.rank-badge-display {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: var(--space-xl) 0;
}

.rank-badge-display__icon {
  width: 96px;
  height: 96px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3rem;
  margin-bottom: var(--space-md);
  position: relative;
  box-shadow: var(--shadow-lg);
}
.rank-badge-display__icon--bronze { background: linear-gradient(135deg, var(--rank-bronze), #B06A28); }
.rank-badge-display__icon--silver { background: linear-gradient(135deg, var(--rank-silver), #A8A8A8); }
.rank-badge-display__icon--gold { background: linear-gradient(135deg, var(--rank-gold), #E5B400); }
.rank-badge-display__icon--diamond { background: linear-gradient(135deg, var(--rank-diamond), var(--rank-diamond-stroke)); }
.rank-badge-display__icon--master { background: linear-gradient(135deg, var(--rank-master), #FF4757); }

.rank-badge-display__name {
  font-size: var(--text-xl);
  font-weight: 800;
}

.rank-badge-display__sub {
  font-size: var(--text-sm);
  color: var(--color-text-light);
}

/* Stats cards */
.stats-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-sm);
  margin-bottom: var(--space-lg);
}

.stat-card {
  background: var(--color-card);
  border-radius: var(--radius-md);
  padding: var(--space-md);
  text-align: center;
  box-shadow: var(--shadow-sm);
}

.stat-card__value {
  font-size: var(--text-2xl);
  font-weight: 800;
  color: var(--color-secondary);
}

.stat-card__label {
  font-size: var(--text-xs);
  color: var(--color-muted);
  margin-top: var(--space-xs);
}

/* Radar chart placeholder */
.radar-chart-area {
  background: var(--color-card);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  margin-bottom: var(--space-lg);
  box-shadow: var(--shadow-sm);
  min-height: 200px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.radar-chart-area__placeholder {
  color: var(--color-muted);
  font-size: var(--text-sm);
}

/* Weakness list */
.weakness-section {
  margin-bottom: var(--space-lg);
}

.weakness-section__title {
  font-size: var(--text-base);
  font-weight: 700;
  margin-bottom: var(--space-md);
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.weakness-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-md);
  background: var(--color-card);
  border-radius: var(--radius-md);
  margin-bottom: var(--space-sm);
  box-shadow: var(--shadow-sm);
}

.weakness-item__name {
  font-weight: 600;
  font-size: var(--text-sm);
}

.weakness-item__accuracy {
  font-size: var(--text-sm);
  font-weight: 700;
  color: var(--color-danger);
}

/* Error notebook (错题本) */
.mistake-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.mistake-item {
  padding: var(--space-md);
  background: var(--color-card);
  border-radius: var(--radius-md);
  border-left: 4px solid var(--color-danger);
  box-shadow: var(--shadow-sm);
}

.mistake-item__top {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  margin-bottom: var(--space-xs);
}

.mistake-item__unit {
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-text-light);
}

.mistake-item__date {
  margin-left: auto;
  font-size: var(--text-xs);
  color: var(--color-muted);
}

.mistake-item__skill {
  font-size: var(--text-xs);
  color: var(--color-text-light);
  margin-bottom: var(--space-xs);
}

.mistake-item__preview {
  font-size: var(--text-sm);
  color: var(--color-text);
  line-height: 1.5;
}

/* PET mock challenge (BOSS) card — .card.boss-card to win source-order over .card */
.boss-card.card {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  padding: var(--space-lg);
  cursor: pointer;
  color: #fff;
  background: linear-gradient(135deg, #7b2ff7, #f107a3);
  border: none;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.boss-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(123, 47, 247, 0.35);
}

.boss-card__icon {
  font-size: 2.5rem;
  line-height: 1;
  flex-shrink: 0;
}

.boss-card__info {
  flex: 1;
}

.boss-card__title {
  font-weight: 800;
  font-size: 1.1rem;
  margin-bottom: var(--space-xs);
}

.boss-card__desc {
  font-size: var(--text-sm);
  opacity: 0.92;
  line-height: 1.5;
}

.boss-card__chevron {
  font-size: 1.8rem;
  opacity: 0.8;
  flex-shrink: 0;
}

/* Badge collection grid */
.badge-collection {
  margin-bottom: var(--space-lg);
}

.badge-collection__title {
  font-size: var(--text-base);
  font-weight: 700;
  margin-bottom: var(--space-md);
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.badge-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-md);
}

.badge-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-xs);
}

.badge-item__icon {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-md);
  background: var(--color-card);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.8rem;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-fast);
}

.badge-item__name {
  font-size: var(--text-xs);
  color: var(--color-text-light);
  text-align: center;
}

.badge-item--locked .badge-item__icon {
  background: var(--color-bg);
  filter: grayscale(1);
  opacity: 0.4;
}

/* ============================================================
   RESULT / SUMMARY SCREEN
   ============================================================ */
.view-result {
  padding: var(--space-lg) var(--space-md);
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  min-height: 100dvh;
}

.result-stars {
  display: flex;
  gap: var(--space-md);
  margin: var(--space-xl) 0;
}

.result-star {
  font-size: 3rem;
  opacity: 0.2;
  transform: scale(0);
  transition: transform 0.5s ease, opacity 0.5s ease;
}
.result-star--earned {
  opacity: 1;
  animation: starEarn 0.6s ease forwards;
}
.result-star--earned:nth-child(2) {
  animation-delay: 0.2s;
}
.result-star--earned:nth-child(3) {
  animation-delay: 0.4s;
}

.result-title {
  font-size: var(--text-2xl);
  font-weight: 800;
  margin-bottom: var(--space-sm);
}

.result-subtitle {
  font-size: var(--text-sm);
  color: var(--color-text-light);
  margin-bottom: var(--space-xl);
}

.result-breakdown {
  width: 100%;
  background: var(--color-card);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  box-shadow: var(--shadow-sm);
  margin-bottom: var(--space-lg);
}

.result-breakdown__row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-sm) 0;
}
.result-breakdown__row:not(:last-child) {
  border-bottom: 1px solid var(--color-border);
}

.result-breakdown__label {
  font-size: var(--text-sm);
  color: var(--color-text-light);
}

.result-breakdown__value {
  font-weight: 700;
  font-size: var(--text-base);
}

.result-xp {
  font-size: var(--text-3xl);
  font-weight: 800;
  color: var(--color-warning);
  margin-bottom: var(--space-md);
}

.result-weakness {
  width: 100%;
  background: rgba(255, 75, 75, 0.06);
  border: 1px solid rgba(255, 75, 75, 0.15);
  border-radius: var(--radius-md);
  padding: var(--space-md);
  margin-bottom: var(--space-lg);
  text-align: left;
}

.result-weakness__title {
  font-weight: 700;
  font-size: var(--text-sm);
  color: var(--color-danger);
  margin-bottom: var(--space-sm);
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.result-weakness__list {
  font-size: var(--text-sm);
  color: var(--color-text-light);
  line-height: 1.6;
}

.result-actions {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  width: 100%;
}

/* ============================================================
   GENERAL COMPONENTS
   ============================================================ */

/* Buttons */
.btn-primary {
  display: block;
  width: 100%;
  padding: var(--space-md) var(--space-lg);
  background: var(--color-primary);
  color: #fff;
  font-size: var(--text-base);
  font-weight: 700;
  border-radius: var(--radius-lg);
  text-align: center;
  box-shadow: 0 4px 0 var(--color-primary-dark);
  transition: all var(--transition-fast);
  text-transform: none;
}
.btn-primary:active {
  transform: translateY(3px);
  box-shadow: 0 1px 0 var(--color-primary-dark);
}
.btn-primary:disabled {
  background: var(--color-muted);
  box-shadow: 0 4px 0 #999;
  cursor: not-allowed;
}

.btn-secondary {
  display: block;
  width: 100%;
  padding: var(--space-md) var(--space-lg);
  background: transparent;
  color: var(--color-secondary);
  font-size: var(--text-base);
  font-weight: 700;
  border-radius: var(--radius-lg);
  border: 2px solid var(--color-secondary);
  text-align: center;
  transition: all var(--transition-fast);
}
.btn-secondary:active {
  background: rgba(28, 176, 246, 0.08);
}

.btn-danger {
  display: block;
  width: 100%;
  padding: var(--space-md) var(--space-lg);
  background: var(--color-danger);
  color: #fff;
  font-size: var(--text-base);
  font-weight: 700;
  border-radius: var(--radius-lg);
  box-shadow: 0 4px 0 var(--color-danger-dark);
  text-align: center;
  transition: all var(--transition-fast);
}
.btn-danger:active {
  transform: translateY(3px);
  box-shadow: 0 1px 0 var(--color-danger-dark);
}

/* BEM button system (used by placement / plan / review / settings views) */
.btn {
  display: inline-block;
  padding: var(--space-sm) var(--space-lg);
  border: none;
  border-radius: var(--radius-lg);
  font-size: var(--text-base);
  font-weight: 700;
  text-align: center;
  cursor: pointer;
  transition: all var(--transition-fast);
}
.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}
.btn--large {
  padding: var(--space-md) var(--space-lg);
  font-size: var(--text-lg);
}
.btn--primary {
  background: var(--color-primary);
  color: #fff;
  box-shadow: 0 4px 0 var(--color-primary-dark);
}
.btn--primary:active {
  transform: translateY(3px);
  box-shadow: 0 1px 0 var(--color-primary-dark);
}
.btn--secondary {
  background: transparent;
  color: var(--color-secondary);
  border: 2px solid var(--color-secondary);
}
.btn--secondary:active {
  background: rgba(28, 176, 246, 0.08);
}
.btn--danger {
  background: var(--color-danger);
  color: #fff;
  box-shadow: 0 4px 0 var(--color-danger-dark);
}
.btn--danger:active {
  transform: translateY(3px);
  box-shadow: 0 1px 0 var(--color-danger-dark);
}

/* Confetti celebration */
.confetti-layer {
  position: fixed;
  inset: 0;
  pointer-events: none;
  overflow: hidden;
  z-index: 9999;
}
.confetti-piece {
  position: absolute;
  top: -20px;
  border-radius: 2px;
  opacity: 0.95;
  animation-name: confetti-fall;
  animation-timing-function: ease-in;
  animation-fill-mode: forwards;
}
@keyframes confetti-fall {
  0% {
    transform: translateY(0) translateX(0) rotate(0deg);
    opacity: 1;
  }
  100% {
    transform: translateY(102vh) translateX(var(--drift)) rotate(var(--rotate));
    opacity: 0.9;
  }
}
@media (prefers-reduced-motion: reduce) {
  .confetti-layer { display: none; }
}

/* Settings view */
.settings-group {
  background: var(--color-card);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  margin-bottom: var(--space-md);
  box-shadow: var(--shadow-sm);
}
.settings-group--danger {
  border: 1px solid var(--color-danger);
}
.settings-group__title {
  font-weight: 700;
  font-size: var(--text-base);
  margin-bottom: var(--space-xs);
}
.settings-group__desc {
  font-size: var(--text-sm);
  color: var(--color-text-light);
  line-height: 1.5;
  margin-bottom: var(--space-sm);
}
.goal-options {
  display: flex;
  gap: var(--space-sm);
}
.goal-option {
  flex: 1;
  padding: var(--space-md);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-bg);
  font-weight: 700;
  cursor: pointer;
  transition: all var(--transition-fast);
}
.goal-option--active {
  border-color: var(--color-primary);
  background: var(--color-primary);
  color: #fff;
}
.settings-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.settings-row__label {
  font-weight: 700;
  font-size: var(--text-base);
}
.settings-row__desc {
  font-size: var(--text-sm);
  color: var(--color-text-light);
}
.toggle {
  width: 52px;
  height: 30px;
  border-radius: var(--radius-full);
  background: var(--color-muted);
  border: none;
  position: relative;
  cursor: pointer;
  transition: background var(--transition-fast);
  flex-shrink: 0;
}
.toggle--on {
  background: var(--color-primary);
}
.toggle__knob {
  position: absolute;
  top: 3px;
  left: 3px;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: #fff;
  transition: transform var(--transition-fast);
}
.toggle--on .toggle__knob {
  transform: translateX(22px);
}
.settings-footer {
  text-align: center;
  font-size: var(--text-sm);
  color: var(--color-text-light);
  margin-top: var(--space-lg);
  line-height: 1.6;
}

/* Account / login */
.sidebar__account {
  display: flex;
  flex-direction: column;
  gap: 2px;
  border: none;
  background: transparent;
  color: var(--color-text);
  padding: var(--space-sm) var(--space-md);
  cursor: pointer;
  text-align: left;
  width: 100%;
  transition: background var(--transition-fast);
}
.sidebar__account:hover { background: var(--color-card); }
.sidebar__account-name {
  font-size: var(--text-lg);
  font-weight: 800;
  color: var(--color-secondary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.sidebar__account:hover .sidebar__account-name { text-decoration: underline; }

.view-account { max-width: 480px; margin: 0 auto; }
.account-card {
  background: var(--color-card);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  margin-bottom: var(--space-md);
  box-shadow: var(--shadow-sm);
  text-align: center;
}
.account-card--form { text-align: left; }
.account-card__icon { font-size: 2.4rem; line-height: 1; }
.account-card__title {
  font-weight: 800;
  font-size: var(--text-lg);
  margin: var(--space-sm) 0;
}
.account-card__desc {
  font-size: var(--text-sm);
  color: var(--color-text-light);
  line-height: 1.6;
}
.account-status {
  margin-top: var(--space-md);
  font-weight: 700;
  color: var(--color-secondary);
}
.account-hint {
  font-size: var(--text-sm);
  color: var(--color-text-light);
  margin-top: var(--space-sm);
  line-height: 1.5;
}

.account-tabs {
  display: flex;
  gap: var(--space-sm);
  margin-bottom: var(--space-md);
}
.account-tab {
  flex: 1;
  padding: var(--space-sm);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-bg);
  font-weight: 700;
  cursor: pointer;
  transition: all var(--transition-fast);
}
.account-tab--active {
  border-color: var(--color-primary);
  background: var(--color-primary);
  color: #fff;
}
.account-field {
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
  margin-bottom: var(--space-md);
  font-weight: 700;
  font-size: var(--text-sm);
}
.account-field input {
  padding: var(--space-md);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: var(--text-base);
  font-family: inherit;
}
.account-field input:focus {
  outline: none;
  border-color: var(--color-primary);
}
.account-submit { width: 100%; }
.account-link {
  display: block;
  margin: var(--space-sm) auto 0;
  background: none;
  border: none;
  color: var(--color-secondary);
  font-size: var(--text-sm);
  font-weight: 700;
  cursor: pointer;
  text-decoration: underline;
}
.account-link:disabled { opacity: 0.5; cursor: default; }
.account-msg {
  font-size: var(--text-sm);
  font-weight: 700;
  min-height: 1.2em;
  margin-bottom: var(--space-sm);
}
.account-msg--error { color: var(--color-danger); }
.account-msg--ok { color: var(--color-primary); }

/* Badges */
.badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-xs) var(--space-sm);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: 700;
  background: var(--color-secondary);
  color: #fff;
}

.badge--success { background: var(--color-primary); }
.badge--warning { background: var(--color-warning); color: var(--color-text); }
.badge--danger { background: var(--color-danger); }

.badge-locked {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-xs) var(--space-sm);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: 700;
  background: var(--color-bg);
  color: var(--color-muted);
  border: 1px dashed var(--color-muted);
}

/* Cards */
.card {
  background: var(--color-card);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  box-shadow: var(--shadow-sm);
}

/* Progress bar */
.progress-bar {
  height: 12px;
  background: var(--color-border);
  border-radius: var(--radius-full);
  overflow: hidden;
  position: relative;
}

.progress-bar__fill {
  height: 100%;
  border-radius: var(--radius-full);
  background: var(--color-primary);
  transition: width 0.5s ease;
  position: relative;
}
.progress-bar__fill::after {
  content: "";
  position: absolute;
  top: 2px;
  left: 4px;
  right: 4px;
  height: 4px;
  background: rgba(255, 255, 255, 0.35);
  border-radius: var(--radius-full);
}

.progress-bar--secondary .progress-bar__fill {
  background: var(--color-secondary);
}

.progress-bar--warning .progress-bar__fill {
  background: var(--color-warning);
}

.progress-bar--small {
  height: 8px;
}

/* Toast notifications */
.toast {
  position: fixed;
  top: calc(var(--nav-height) + var(--space-md));
  left: 50%;
  transform: translateX(-50%);
  max-width: calc(var(--max-width) - var(--space-lg) * 2);
  width: max-content;
  padding: var(--space-md) var(--space-lg);
  background: var(--color-text);
  color: #fff;
  border-radius: var(--radius-full);
  font-size: var(--text-sm);
  font-weight: 600;
  z-index: 500;
  box-shadow: var(--shadow-lg);
  animation: slideDown 0.3s ease, fadeIn 0.3s ease;
  pointer-events: none;
}

.toast--success { background: var(--color-primary); }
.toast--warning { background: var(--color-warning); color: var(--color-text); }
.toast--error { background: var(--color-danger); }

/* Modal / Overlay */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: var(--color-overlay);
  z-index: 400;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-lg);
  animation: fadeIn 0.2s ease;
}

.modal {
  background: var(--color-card);
  border-radius: var(--radius-xl);
  padding: var(--space-xl);
  width: 100%;
  max-width: 360px;
  text-align: center;
  animation: slideUp 0.3s ease;
  box-shadow: var(--shadow-lg);
}

.modal__icon {
  font-size: 4rem;
  margin-bottom: var(--space-md);
}

.modal__title {
  font-size: var(--text-2xl);
  font-weight: 800;
  margin-bottom: var(--space-sm);
}

.modal__subtitle {
  font-size: var(--text-sm);
  color: var(--color-text-light);
  margin-bottom: var(--space-lg);
  line-height: 1.6;
}

.modal__actions {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

/* Level up celebration */
.celebration-modal .modal__icon {
  animation: bounce 0.6s ease infinite alternate;
}

.celebration-modal .modal__title {
  background: linear-gradient(135deg, var(--color-warning), #FF8C00);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* Badge earned modal */
.badge-earned-modal .modal__icon {
  animation: starEarn 0.8s ease forwards;
}

/* ============================================================
   KEYFRAME ANIMATIONS
   ============================================================ */

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes slideUp {
  from { opacity: 0; transform: translateY(24px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes slideDown {
  from { opacity: 0; transform: translate(-50%, -16px); }
  to { opacity: 1; transform: translate(-50%, 0); }
}

@keyframes pulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(88, 204, 2, 0.4); }
  50% { box-shadow: 0 0 0 12px rgba(88, 204, 2, 0); }
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  15% { transform: translateX(-8px); }
  30% { transform: translateX(8px); }
  45% { transform: translateX(-6px); }
  60% { transform: translateX(6px); }
  75% { transform: translateX(-3px); }
  90% { transform: translateX(3px); }
}

@keyframes bounce {
  0%, 100% { transform: translateY(0); }
  30% { transform: translateY(-12px); }
  50% { transform: translateY(-6px); }
  70% { transform: translateY(-10px); }
}

@keyframes heartBreak {
  0% { transform: scale(1); opacity: 1; }
  25% { transform: scale(1.3); }
  50% { transform: scale(0.8) rotate(-15deg); opacity: 0.6; }
  75% { transform: scale(0.5) rotate(10deg); opacity: 0.3; }
  100% { transform: scale(0.8) rotate(0); opacity: 0.25; }
}

@keyframes starEarn {
  0% { transform: scale(0) rotate(-180deg); opacity: 0; }
  60% { transform: scale(1.3) rotate(10deg); opacity: 1; }
  80% { transform: scale(0.9) rotate(-5deg); }
  100% { transform: scale(1) rotate(0); opacity: 1; }
}

@keyframes confetti {
  0% { transform: translateY(0) rotate(0deg); opacity: 1; }
  100% { transform: translateY(-120px) rotate(720deg); opacity: 0; }
}

@keyframes sparkle {
  0%, 100% { opacity: 0; transform: scale(0) rotate(0deg); }
  50% { opacity: 1; transform: scale(1) rotate(180deg); }
}

@keyframes comboFire {
  0% { transform: translateX(-50%) scale(0.5); opacity: 0; }
  50% { transform: translateX(-50%) scale(1.15); }
  100% { transform: translateX(-50%) scale(1); opacity: 1; }
}

@keyframes comboFireIcon {
  from { transform: scale(1) rotate(-5deg); }
  to { transform: scale(1.2) rotate(5deg); }
}

/* Sparkle particles (utility class) */
.sparkle-particle {
  position: absolute;
  width: 8px;
  height: 8px;
  background: var(--color-warning);
  border-radius: 50%;
  pointer-events: none;
  animation: sparkle 0.8s ease forwards;
}

/* Confetti particle */
.confetti-particle {
  position: fixed;
  width: 10px;
  height: 10px;
  border-radius: 2px;
  pointer-events: none;
  z-index: 600;
  animation: confetti 1.2s ease forwards;
}

/* ============================================================
   SECTION TITLES & UTILITIES
   ============================================================ */
.section-title {
  font-size: var(--text-lg);
  font-weight: 700;
  margin-bottom: var(--space-md);
}

.text-center { text-align: center; }
.text-muted { color: var(--color-muted); }
.text-primary { color: var(--color-primary); }
.text-secondary { color: var(--color-secondary); }
.text-danger { color: var(--color-danger); }
.text-warning { color: var(--color-warning); }

.mt-sm { margin-top: var(--space-sm); }
.mt-md { margin-top: var(--space-md); }
.mt-lg { margin-top: var(--space-lg); }
.mb-sm { margin-bottom: var(--space-sm); }
.mb-md { margin-bottom: var(--space-md); }
.mb-lg { margin-bottom: var(--space-lg); }

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
}

/* ============================================================
   RESPONSIVE: TABLET (>=768px)
   ============================================================ */
@media (min-width: 768px) {
  :root {
    --max-width: 540px;
    --nav-height: 60px;
    --tab-height: 64px;
  }

  html {
    font-size: 17px;
  }

  .choices-grid {
    gap: var(--space-md);
  }

  .portfolio-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .badge-grid {
    grid-template-columns: repeat(5, 1fr);
  }

  .stats-cards {
    gap: var(--space-md);
  }

  .unit-node__circle {
    width: 80px;
    height: 80px;
    font-size: var(--text-3xl);
  }

  .modal {
    max-width: 400px;
    padding: var(--space-2xl);
  }

  .result-star {
    font-size: 4rem;
  }
}

/* ============================================================
   RESPONSIVE: DESKTOP (>=1024px)
   ============================================================ */
@media (min-width: 1024px) {
  html {
    font-size: 16px;
  }

  /* Hover states on desktop */
  .choice-btn:hover {
    border-color: var(--color-secondary);
    background: rgba(28, 176, 246, 0.04);
  }

  .unit-node:hover .unit-node__circle {
    transform: scale(1.08);
  }

  .phase-card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
  }

  .portfolio-card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
  }

  .word-chip:hover {
    border-color: var(--color-secondary);
    background: rgba(28, 176, 246, 0.04);
  }

  .btn-primary:hover:not(:disabled) {
    filter: brightness(1.05);
  }

  .btn-secondary:hover {
    background: rgba(28, 176, 246, 0.06);
  }

  .chat-choice-btn:hover {
    background: rgba(28, 176, 246, 0.08);
  }

  .badge-item__icon:hover {
    transform: scale(1.1);
  }

  .match-item:hover:not(.match-item--matched) {
    border-color: var(--color-secondary);
    background: rgba(28, 176, 246, 0.04);
  }
}

/* ============================================================
   DARK MODE SUPPORT (respects system preference)
   ============================================================ */
@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #1A1A2E;
    --color-card: #232340;
    --color-text: #E8E8E8;
    --color-text-light: #AEAECC;
    --color-muted: #6B6B8D;
    --color-border: #3A3A5C;
    --color-overlay: rgba(0, 0, 0, 0.65);
  }

  .fill-input {
    background: rgba(28, 176, 246, 0.12);
  }
  .fill-input:focus {
    background: rgba(28, 176, 246, 0.18);
  }

  .word-chip {
    background: var(--color-card);
    border-color: var(--color-border);
    box-shadow: 0 2px 0 var(--color-border);
  }

  .choice-btn {
    background: var(--color-card);
    border-color: var(--color-border);
    box-shadow: var(--shadow-btn) rgba(0, 0, 0, 0.3);
  }

  @media (min-width: 1024px) {
    body {
      background: #12122A;
    }
  }
}

/* ============================================================
   PARENT ZONE
   ============================================================ */
.parent-zone {
  display: flex;
  justify-content: center;
  padding: var(--space-xl) var(--space-md);
}
.parent-card {
  background: var(--color-card);
  border-radius: 16px;
  padding: var(--space-xl);
  width: 100%;
  max-width: 420px;
  box-shadow: 0 2px 12px rgba(0,0,0,0.08);
  text-align: center;
}
.parent-card--wide {
  max-width: 700px;
  text-align: left;
}
.parent-icon {
  font-size: 48px;
  margin-bottom: var(--space-md);
}
.parent-card h2 {
  margin: 0 0 var(--space-sm);
  font-size: 1.3rem;
}
.parent-desc {
  color: var(--color-text-light);
  font-size: 0.9rem;
  margin-bottom: var(--space-lg);
  line-height: 1.5;
}
.parent-field {
  text-align: left;
  margin-bottom: var(--space-md);
}
.parent-field label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: var(--space-xs);
  color: var(--color-text);
}
.parent-field input {
  width: 100%;
  padding: 10px 14px;
  border: 2px solid var(--color-border);
  border-radius: 10px;
  font-size: 1rem;
  letter-spacing: 4px;
  text-align: center;
  box-sizing: border-box;
  transition: border-color 0.2s;
}
.parent-field input:focus {
  outline: none;
  border-color: var(--color-secondary);
}
.parent-field input[type="password"]:not([inputmode]) {
  letter-spacing: normal;
  text-align: left;
}

/* Structured course-creation wizard */
.curr-form .parent-field input,
.curr-form .parent-field select,
.curr-form .parent-field textarea {
  letter-spacing: normal;
  text-align: left;
  font-family: inherit;
}
.curr-form .parent-field select,
.curr-form .parent-field textarea {
  width: 100%;
  padding: 10px 14px;
  border: 2px solid var(--color-border);
  border-radius: 10px;
  font-size: 1rem;
  box-sizing: border-box;
  background: var(--color-card);
  color: var(--color-text);
  transition: border-color 0.2s;
}
.curr-form .parent-field select:focus,
.curr-form .parent-field textarea:focus {
  outline: none;
  border-color: var(--color-secondary);
}
.curr-form .parent-field textarea { min-height: 60px; resize: vertical; line-height: 1.5; }
.curr-form-row { display: flex; gap: var(--space-md); }
.curr-form-row .parent-field { flex: 1; min-width: 0; }
@media (max-width: 560px) { .curr-form-row { flex-direction: column; gap: 0; } }
.parent-msg {
  min-height: 1.4em;
  font-size: 0.85rem;
  margin-bottom: var(--space-sm);
}
.parent-msg--error { color: var(--color-danger); }
.parent-msg--success { color: var(--color-primary); }

.parent-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--space-lg);
}
.parent-header h2 { margin: 0; }

.parent-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: var(--space-md);
  margin-bottom: var(--space-lg);
}
/* 两张「怎么拿到一套课程」的卡是一对，固定两列，不让 auto-fit 把它们
   拉成三列的宽度、也不让学习报告混进来凑数 */
.parent-grid--pair { grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }

/* 「申请专业定制」是一条两步流程：先申请，收到文件再导入。
   导入按钮原来孤零零挂在课程列表下面，看不出属于哪一步。 */
.parent-feature.parent-feature--steps {
  text-align: left;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
  display: flex;
  flex-direction: column;
}
.parent-feature--steps .parent-feature-icon,
.parent-feature--steps h3 { text-align: center; }
.parent-feature--steps > p { text-align: center; }

.feature-steps {
  list-style: none;
  margin: var(--space-md) 0 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}
.feature-steps > li {
  display: flex;
  gap: var(--space-sm);
  align-items: flex-start;
}
.feature-steps__n {
  flex-shrink: 0;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--color-primary);
  color: #fff;
  font-size: 0.72rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-top: 2px;
}
.feature-steps__body {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 6px;
}
.feature-steps__t { font-size: var(--text-sm); line-height: 1.6; text-align: left; }
.feature-steps__hint {
  font-size: var(--text-xs);
  color: var(--color-muted);
  line-height: 1.6;
  text-align: left;
}
.feature-steps .btn { margin: 0; }

.parent-section-title {
  margin: var(--space-lg) 0 var(--space-sm);
  font-size: 1rem;
  font-weight: 700;
  color: var(--color-text);
}

/* 学习报告跟「定制课程」不是一回事：那两张是「去拿一套课」，这条是
   「看看孩子学得怎么样」。挤在同一行会让人以为三选一。 */
.parent-report-row {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  padding: var(--space-md);
  margin-bottom: var(--space-lg);
  background: var(--color-bg);
  border-radius: 12px;
  text-decoration: none;
  color: inherit;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
  transition: transform 0.15s, box-shadow 0.15s;
}
.parent-report-row:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.10);
}
.parent-report-row:active { transform: translateY(0); }
.parent-report-row__icon { font-size: 28px; flex-shrink: 0; line-height: 1; }
.parent-report-row__text { flex: 1; min-width: 0; display: flex; flex-direction: column; gap: 2px; }
.parent-report-row__text strong { font-size: 1rem; }
.parent-report-row__text span { font-size: var(--text-xs); color: var(--color-text-light); }
.parent-report-row__btn { flex-shrink: 0; margin: 0; }

@media (max-width: 480px) {
  .parent-report-row { flex-wrap: wrap; }
  .parent-report-row__btn { width: 100%; text-align: center; }
}
.parent-feature {
  background: var(--color-bg);
  border-radius: 12px;
  padding: var(--space-lg) var(--space-md);
  text-align: center;
  position: relative;
}
.parent-feature--active {
  transition: transform 0.15s, box-shadow 0.15s;
  box-shadow: 0 2px 8px rgba(0,0,0,0.06);
}
.parent-feature--active:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 16px rgba(0,0,0,0.10);
}
.parent-feature--active:active {
  transform: translateY(0);
}
.parent-feature-icon {
  font-size: 36px;
  margin-bottom: var(--space-sm);
}
.parent-feature h3 {
  font-size: 1rem;
  margin: 0 0 var(--space-xs);
}
.parent-feature p {
  font-size: 0.8rem;
  color: var(--color-text-light);
  margin: 0 0 var(--space-sm);
  line-height: 1.4;
}
.parent-coming {
  display: inline-block;
  background: var(--color-warning-light);
  color: #8a6d00;
  font-size: 0.7rem;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 8px;
}
.parent-actions {
  border-top: 1px solid var(--color-border);
  padding-top: var(--space-md);
}
@keyframes pulse { 50% { opacity: 0.5; } }

.btn--secondary {
  background: var(--color-secondary);
  color: #fff;
  border: none;
  border-radius: 10px;
  padding: 10px 20px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
}
.btn--secondary:disabled {
  background: #ccc;
  cursor: not-allowed;
}

/* --- Course Editor --- */
.ce-section { margin-bottom: var(--space-lg); }
.ce-section-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--space-md);
}
.ce-section-header h3 { margin: 0; }
.ce-pack-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-md);
  background: var(--color-bg);
  border-radius: 10px;
  margin-bottom: var(--space-sm);
}
.ce-pack-info { flex: 1; min-width: 0; }
.ce-pack-info strong { display: block; margin-bottom: 2px; }
.ce-pack-meta { font-size: 0.8rem; color: var(--color-text-light); }
.ce-pack-desc {
  display: block;
  font-size: 0.8rem;
  color: var(--color-muted);
  margin-top: 2px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.ce-pack-btns { display: flex; gap: var(--space-xs); flex-shrink: 0; margin-left: var(--space-sm); }
.ce-meta .parent-field input { letter-spacing: normal; text-align: left; }
.ce-form .parent-field input { letter-spacing: normal; text-align: left; }
.ce-spinner {
  display: inline-block;
  width: 20px;
  height: 20px;
  border: 3px solid var(--color-border);
  border-top-color: var(--color-secondary);
  border-radius: 50%;
  animation: ce-spin 0.7s linear infinite;
}
@keyframes ce-spin { to { transform: rotate(360deg); } }

.btn--tiny {
  padding: 4px 10px;
  font-size: 0.75rem;
  border-radius: 6px;
  border: 1px solid var(--color-border);
  background: var(--color-card);
  cursor: pointer;
}
.btn--tiny:hover { background: var(--color-bg); }
.btn--danger-text { color: var(--color-danger); border-color: transparent; }
.btn--danger-text:hover { background: #fff0f0; }

/* 家长入口紧跟在菜单末尾，用一条细分隔线表示"这一项不一样"。
   曾经用 margin-top:auto 把它顶到侧边栏底部，但侧边栏本来就比内容高，
   那样会在菜单中间留下一段空白，看起来像少了一个菜单项。
   现在留白落在列表末尾，是正常的"列表到此为止"。 */
.sidebar__item[data-route="parent"] {
  margin-top: var(--space-sm);
  opacity: 0.75;
  position: relative;
}
.sidebar__item[data-route="parent"]::before {
  content: "";
  position: absolute;
  left: var(--space-md);
  right: var(--space-md);
  top: calc(var(--space-xs) * -1);
  height: 1px;
  background: var(--color-border);
}
.sidebar__item[data-route="parent"].active,
.sidebar__item[data-route="parent"]:hover {
  opacity: 1;
}

/* Sidebar curriculum indicator — a status card (not a nav item),
   aligned flush with the nav items below it. */
.sidebar__curriculum {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: var(--space-sm) var(--space-md);
  margin: 0 0 var(--space-sm);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-left: 3px solid var(--color-primary);
  border-radius: var(--radius-md);
  min-width: 0;
}
.sidebar__curriculum-label {
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-muted);
  letter-spacing: 0.02em;
}
.sidebar__curriculum-name {
  min-width: 0;
  font-size: var(--text-sm);
  font-weight: 700;
  color: var(--color-text);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* Curriculum switcher on home page */
.curr-switcher {
  padding: var(--space-md) !important;
}
.curr-switcher__header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-sm);
  margin-bottom: var(--space-sm);
  font-size: var(--text-sm);
}
.curr-switcher__label {
  color: var(--color-text-light);
  flex-shrink: 0;
}
.curr-switcher__current {
  min-width: 0;
  text-align: right;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.curr-switcher__list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-xs);
}
.curr-switch-btn {
  padding: 6px 14px;
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-pill);
  background: var(--color-card);
  font-size: 0.8rem;
  cursor: pointer;
  transition: all 0.15s ease;
  white-space: nowrap;
  max-width: 100%;
  overflow: hidden;
  text-overflow: ellipsis;
}
.curr-switch-btn:hover {
  border-color: var(--color-primary);
  color: var(--color-primary-dark);
}
.curr-switch-btn--active {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
  cursor: default;
  font-weight: 600;
}

/* Batch unit-generation progress */
.batch-sub {
  font-size: var(--text-sm);
  color: var(--color-text-light);
  margin: var(--space-sm) 0 var(--space-md);
  line-height: 1.6;
}
.batch-progress {
  height: 14px;
  background: var(--color-border);
  border-radius: var(--radius-pill);
  overflow: hidden;
}
.batch-progress__fill {
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--color-primary), var(--color-secondary));
  border-radius: var(--radius-pill);
  transition: width 0.3s ease;
}
.batch-status {
  margin-top: var(--space-sm);
  font-size: var(--text-sm);
  color: var(--color-text-light);
}
#batchActions {
  margin-top: var(--space-lg);
  display: flex;
  gap: var(--space-md);
  flex-wrap: wrap;
}

/* Unit node: needs generation indicator */
.unit-node--needs-gen .unit-node__circle {
  border-style: dashed;
  opacity: 0.7;
}
.unit-node--needs-gen .unit-node__name::after {
  content: ' 🤖';
  font-size: 0.7em;
}

.btn--tiny.btn--primary {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
}
.btn--tiny.btn--primary:hover {
  background: var(--color-primary-dark);
}

/* ============================================================
   REDUCED MOTION
   ============================================================ */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* ============================================================
   NARROW WINDOW FALLBACK (<= 720px) — keeps layout usable if
   the PC window is shrunk; primary target is wide desktop.
   ============================================================ */
@media (max-width: 720px) {
  .layout {
    flex-direction: column;
  }
  .sidebar {
    flex-basis: auto;
    width: 100%;
    height: auto;
    position: sticky;
    top: 0;
    flex-direction: row;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-sm) var(--space-md);
    border-right: none;
    border-bottom: 2px solid var(--color-border);
    overflow-x: auto;
  }
  .sidebar__brand { border-bottom: none; margin-bottom: 0; padding: 0; }
  .sidebar__brand-text { display: none; }
  .sidebar__curriculum { display: none; }
  .sidebar__nav { flex-direction: row; flex: 1; }
  .sidebar__item[data-route="parent"] { margin-top: 0; }
  .sidebar__item[data-route="parent"]::before { display: none; }
  .sidebar__item { padding: var(--space-sm) var(--space-md); white-space: nowrap; }
  .sidebar__item-label { display: none; }
  .sidebar__footer {
    border-top: none;
    padding-top: 0;
    margin-top: 0;
    white-space: nowrap;
  }
  .sidebar__account-panel { border: none; background: transparent; border-radius: 0; }
  .sidebar__stats { display: none; }
  /* 手机上账号块和其他导航一样只留图标，名字和「当前家长账号登录中」收起来，
     不然这一块比整条导航还宽，被推到屏幕外只露半截 */
  .sidebar__account-text,
  .sidebar__account-role { display: none; }

  /* 六个图标均分整行：5 个导航 + 账号。原来每格固定 60px 加间距一共 418px，
     390 宽的手机放不下，360 宽的更放不下。均分后每格随屏宽伸缩。 */
  .sidebar { gap: 0; padding-left: var(--space-xs); padding-right: var(--space-xs); }
  .sidebar__nav { flex: 6 1 0; min-width: 0; gap: 0; }   /* 6 个导航 + 1 个账号，七格均分 */
  .sidebar__item {
    flex: 1 1 0;
    min-width: 0;
    justify-content: center;
    padding-left: 0;
    padding-right: 0;
  }
  .sidebar__footer { flex: 1 1 0; min-width: 0; display: flex; }
  .sidebar__account-panel { flex: 1; display: flex; }
  .sidebar__account {
    flex: 1;
    width: auto;
    padding: var(--space-sm) 0;
    display: flex;
    align-items: center;
    justify-content: center;
  }
  .content { padding: var(--space-md); }
  .topbar { padding: 0 var(--space-md); }

  /* 课程体系列表：窄屏时让按钮换行到信息下方，避免长标题挤压切换/删除按钮 */
  .ce-pack-item { flex-wrap: wrap; }
  .ce-pack-info { flex-basis: 100%; }
  .ce-pack-btns { margin-left: 0; margin-top: var(--space-sm); }
  .parent-header { flex-wrap: wrap; gap: var(--space-sm); }
  #batchActions .btn { flex: 1; }
}

/* ---------------------------------------------------------------
   段位阶梯（「我的进度」页）。首页只放一条状态条——
   参照多邻国：排位/联赛在独立页面，首页留给"今天练什么"。
   --------------------------------------------------------------- */
.rank-ladder__head {
  font-size: var(--text-sm);
  font-weight: 700;
  text-align: center;
  margin-bottom: var(--space-sm);
}
.rank-ladder__pos {
  font-weight: 400;
  color: var(--color-text-light);
}
.rank-ladder__track {
  display: flex;
  align-items: center;
  gap: 2px;
  margin-bottom: var(--space-sm);
}
.rank-step {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  flex: 0 0 auto;
  padding: 4px 6px;
  border-radius: var(--radius-md, 8px);
  line-height: 1.1;
}
.rank-step__icon { font-size: 1.15rem; }
.rank-step__name {
  font-size: 0.68rem;
  color: var(--color-text-light);
  white-space: nowrap;
}
.rank-step__sep {
  flex: 1 1 auto;
  height: 2px;
  background: var(--color-border);
  border-radius: var(--radius-full);
}
.rank-step--done .rank-step__icon { opacity: 0.55; }
.rank-step--done .rank-step__name { opacity: 0.7; }
.rank-step--todo { opacity: 0.32; filter: grayscale(1); }
.rank-step--current {
  background: var(--color-bg);
  box-shadow: inset 0 0 0 2px var(--color-primary);
}
.rank-step--current .rank-step__icon { font-size: 1.4rem; }
.rank-step--current .rank-step__name {
  color: var(--color-text);
  font-weight: 700;
}

/* 课程名做成可点的链接，通向语法提纲 */
.curr-syllabus-link {
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  flex-wrap: wrap;
  justify-content: flex-end;
  white-space: normal;
  overflow: visible;
  color: inherit;
  font-weight: 700;
  text-decoration: none;
  cursor: pointer;
}
.curr-syllabus-link:hover { text-decoration: underline; }
.curr-syllabus-link__hint {
  font-size: var(--text-xs);
  font-weight: 400;
  color: var(--color-primary);
  white-space: nowrap;
}

/* ---------------------------------------------------------------
   语法提纲页
   --------------------------------------------------------------- */
.syl-head__title {
  font-weight: 700;
  font-size: 1.05rem;
  margin-bottom: var(--space-sm);
}
.syl-head__meta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-xs);
}
.syl-head__goal {
  margin-top: var(--space-sm);
  font-size: var(--text-sm);
  color: var(--color-text-light);
  line-height: 1.7;
}
.syl-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}
.syl-item {
  background: var(--color-card);
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-lg, 12px);
  padding: var(--space-md);
}
.syl-item--link { cursor: pointer; }
.syl-item--link:hover { border-color: var(--color-primary); }
.syl-item__head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-sm);
  margin-bottom: 4px;
}
.syl-item__no {
  font-size: var(--text-xs);
  color: var(--color-text-light);
  font-weight: 700;
  letter-spacing: 0.04em;
}
.syl-item__status {
  font-size: var(--text-xs);
  color: var(--color-text-light);
  flex-shrink: 0;
}
.syl-item__status--done { color: var(--color-primary); font-weight: 700; }
.syl-item__status--pending { color: var(--color-warning, #C08A2E); }
.syl-item__title {
  font-weight: 700;
  line-height: 1.4;
}
.syl-item__desc {
  font-size: var(--text-sm);
  color: var(--color-text-light);
  margin-top: 2px;
  line-height: 1.6;
}
.syl-item__skills {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  margin-top: var(--space-sm);
}
.syl-chip {
  font-size: var(--text-xs);
  padding: 2px 8px;
  border-radius: var(--radius-pill);
  background: var(--color-bg);
  color: var(--color-text-light);
  border: 1px solid var(--color-border);
}
.syl-note {
  font-size: var(--text-sm);
  color: var(--color-text-light);
  line-height: 1.8;
}
.syl-note__title {
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-xs);
}
.syl-note p { margin: 0 0 var(--space-sm); }
.syl-note p:last-child { margin-bottom: 0; }

/* 家长专区：解锁规则说明 */
.parent-lock-hint {
  margin: 0 0 var(--space-md);
  padding: var(--space-sm) var(--space-md);
  background: var(--color-bg);
  border-radius: var(--radius-md, 8px);
  font-size: var(--text-xs);
  color: var(--color-text-light);
  line-height: 1.7;
}
.parent-lock-hint strong { color: var(--color-text); }

/* 顶栏音效开关：每一页都在，孩子随手可静音 */
.topbar__sound {
  flex-shrink: 0;
  width: 30px;
  height: 30px;
  align-self: center;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: none;
  border-radius: var(--radius-full);
  background: transparent;
  font-size: 1.05rem;
  line-height: 1;
  cursor: pointer;
  transition: background var(--transition-fast);
}
.topbar__sound:hover { background: var(--color-bg); }
.topbar__sound--off { opacity: 0.45; filter: grayscale(1); }

/* 首页顶部：左边欢迎语，右边状态条。 */
.home-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-sm) var(--space-md);
  padding: var(--space-xs) var(--space-sm);
  margin-bottom: var(--space-md);
}
.home-header__hello { min-width: 0; }
.home-header__greet {
  font-size: 1.05rem;
  font-weight: 800;
  color: var(--color-text);
  line-height: 1.3;
}
.home-header__sub {
  font-size: var(--text-sm);
  color: var(--color-text-light);
  line-height: 1.6;
  margin-top: 2px;
}
.home-header__sub strong { color: var(--color-primary); }

/* 状态条：段位/积分/连续天数是次要信息，压成一行，点开看详情。 */
.status-strip {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  padding: var(--space-xs) var(--space-sm);
  flex-shrink: 0;
  color: var(--color-text-light);
  font-size: var(--text-sm);
  font-weight: 600;
  text-decoration: none;
  border-radius: var(--radius-md);
  transition: background var(--transition-fast);
}
.status-strip:hover { background: var(--color-card); }
.status-strip__item { white-space: nowrap; }
.status-strip__more {
  margin-left: auto;
  font-weight: 400;
  font-size: var(--text-xs);
  color: var(--color-muted);
}

@media (max-width: 720px) {
  .home-header { align-items: flex-start; }
  .status-strip { padding-left: 0; }
  .status-strip__more { display: none; }
}

/* ---------------------------------------------------------------
   站点带：全站唯一的品牌 + 定位出现位置。
   刻意不 sticky —— 家长进站第一屏必见，孩子往下一滚就让位。
   --------------------------------------------------------------- */
.siteband {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 2px var(--space-sm);
  padding: 10px var(--space-xl);
  background: var(--color-card);
  border-bottom: 1px solid var(--color-border);
}
/* 站点带是通栏的，排在 .layout 之上。宽屏下把它的高度从视口高度里扣掉，
   否则 sticky 的侧边栏会比屏幕高出一截，底部账号面板被挤出可视区。
   限定 min-width：窄屏下侧边栏是横条，高度必须保持 auto。 */
@media (min-width: 721px) {
  .layout { min-height: calc(100dvh - 45px); }
  .sidebar { height: calc(100dvh - 45px); }
}
.siteband__brand {
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  text-decoration: none;
  color: var(--color-text);
  flex-shrink: 0;
}
.siteband__logo { font-size: 1.05rem; line-height: 1; }
.siteband__name { font-weight: 800; font-size: 0.98rem; letter-spacing: 0.01em; }
.siteband__sub { font-weight: 600; font-size: var(--text-xs); color: var(--color-muted); }
.siteband__tagline {
  font-size: var(--text-sm);
  color: var(--color-text-light);
  min-width: 0;
}
.siteband__tagline::before { content: "·"; margin-right: var(--space-sm); color: var(--color-border); }
/* 「?」按钮：紧跟定位语，不抢位置；浮层挂在站点带上定位 */
.siteband { position: relative; }
.siteband__what {
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 16px;
  height: 16px;
  padding: 0;
  border: 0;
  background: none;
  color: var(--color-muted);
  cursor: pointer;
  /* 跟在定位语文字后面，换行时一起走，不会自己掉到下一行去 */
  margin-left: 6px;
  vertical-align: -3px;
  transition: color 0.15s;
}
.siteband__what svg { display: block; fill: currentColor; }
/* 挖空的部分用站点带自己的底色，深色底上也不会变成一块白 */
.siteband__what .siteband__what-mark { fill: var(--color-card); }
.siteband__what:hover,
.siteband__what[aria-expanded="true"] { color: var(--color-secondary); }

.siteband__pop {
  position: absolute;
  top: calc(100% - 4px);
  left: var(--space-xl);
  right: var(--space-xl);
  max-width: 420px;
  z-index: 60;
  padding: var(--space-md);
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  box-shadow: 0 6px 24px rgba(0, 0, 0, 0.13);
  text-align: left;
}
.siteband__pop-lead {
  margin: 0 0 var(--space-sm);
  font-size: var(--text-sm);
  line-height: 1.75;
  color: var(--color-text);
}
.siteband__pop-list {
  margin: 0 0 var(--space-sm);
  padding-left: 1.2em;
  font-size: var(--text-xs);
  line-height: 1.85;
  color: var(--color-text-light);
}
.siteband__pop-more {
  font-size: var(--text-xs);
  font-weight: 700;
  color: var(--color-secondary);
  text-decoration: none;
}
.siteband__pop-more:hover { text-decoration: underline; }

@media (max-width: 720px) {
  .siteband__pop { left: var(--space-md); right: var(--space-md); }
}

@media (max-width: 720px) {
  .siteband { padding: 8px var(--space-md); row-gap: 0; }
  .siteband__sub { display: none; }          /* 390px 上省掉「语法冒险」，定位本身已说清 */
  /* 定位语独占一行，音效提到第一行的右端——否则它自己撑起第三行 */
  .siteband__tagline { order: 3; flex-basis: 100%; font-size: var(--text-xs); }
  .siteband__tagline::before { content: none; }
  .siteband .topbar__sound { order: 2; margin-left: auto; }
}

/* ---------------------------------------------------------------
   「这是什么」：定位长文案的正式住址，可以单独发给人
   --------------------------------------------------------------- */
.view-about { max-width: 44em; margin: 0 auto; }
.about-hero { padding: var(--space-md) 0 var(--space-lg); }
.about-hero__title {
  margin: 0 0 var(--space-sm);
  font-size: 1.5rem;
  font-weight: 800;
  line-height: 1.35;
}
.about-hero__lead {
  margin: 0;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--color-text-light);
}
.about-hero__lead strong { color: var(--color-text); }
.about-section {
  padding: var(--space-lg);
  margin-bottom: var(--space-md);
  background: var(--color-card);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
}
.about-section--plain { background: var(--color-bg); box-shadow: none; border: 1px solid var(--color-border); }
.about-section h2 { margin: 0 0 var(--space-sm); font-size: 1.05rem; font-weight: 800; }
.about-section p { margin: 0 0 var(--space-sm); font-size: var(--text-sm); line-height: 1.85; color: var(--color-text-light); }
.about-section p:last-child { margin-bottom: 0; }
.about-section p strong { color: var(--color-text); }
.about-note { font-size: var(--text-xs) !important; color: var(--color-muted) !important; }
.about-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  margin: var(--space-lg) 0 var(--space-xl);
}
.about-actions .btn { text-decoration: none; }

@media (max-width: 720px) {
  .about-hero__title { font-size: 1.22rem; }
  .about-hero__lead { font-size: var(--text-sm); }
  .about-section { padding: var(--space-md); }
  .about-actions .btn { width: 100%; text-align: center; }
}

/* 与内置课程重名的自定义副本：说清两行的区别，别让家长自己猜 */
.ce-pack-dup {
  display: block;
  margin-top: 4px;
  font-size: var(--text-xs);
  line-height: 1.6;
  color: var(--color-warning, #C08A2E);
}

/* 云端保存失败提示：固定在底部，不挡内容，但一定看得见 */
.cloud-banner {
  position: fixed;
  left: 50%;
  bottom: 16px;
  transform: translateX(-50%);
  z-index: 9998;
  display: flex;
  align-items: flex-start;
  gap: var(--space-sm);
  width: min(640px, calc(100vw - 32px));
  padding: var(--space-sm) var(--space-md);
  background: #FFF4E0;
  border: 1px solid var(--color-warning, #C08A2E);
  border-radius: var(--radius-md);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.12);
  font-size: var(--text-sm);
  line-height: 1.7;
  color: var(--color-text);
}
.cloud-banner__text { flex: 1; min-width: 0; }
.cloud-banner__close {
  flex-shrink: 0;
  border: none;
  background: transparent;
  font-size: 1rem;
  line-height: 1;
  cursor: pointer;
  color: var(--color-text-light);
  padding: 2px 4px;
}
@media (max-width: 720px) {
  .cloud-banner { font-size: var(--text-xs); bottom: 8px; }
}

/* 申请定制页 */
.req-list { margin: 0; padding-left: 1.3em; font-size: var(--text-sm); line-height: 1.9; color: var(--color-text-light); }
.req-list strong { color: var(--color-text); }
.req-note { margin: var(--space-sm) 0 0; font-size: var(--text-xs); color: var(--color-muted); line-height: 1.7; }
.req-contact { display: flex; flex-direction: column; gap: var(--space-sm); }
.req-contact__row { display: flex; align-items: center; gap: var(--space-sm); flex-wrap: wrap; }
.req-contact__label { font-size: var(--text-sm); color: var(--color-text-light); min-width: 3em; }
.req-contact__value {
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: var(--text-sm);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm, 6px);
  padding: 3px 10px;
}

/* 结果页说明：题库做完一遍后如实告知有旧题。
   宽度跟着文字走（原来固定 28em，一句话正好挤成两行，末尾孤零零掉个"题。"）。 */
.result-note {
  width: fit-content;
  max-width: min(100%, 44em);
  margin: var(--space-sm) auto 0;
  padding: 8px 14px;
  border-radius: var(--radius-md);
  background: var(--color-bg);
  color: var(--color-text-light);
  font-size: var(--text-xs);
  line-height: 1.7;
  text-align: center;
  text-wrap: balance;
}

/* 语法点的英文原名：中文是主角，英文留个小字方便对照大纲 */
.weakness-item__en {
  margin-top: 1px;
  font-size: var(--text-xs);
  color: var(--color-muted);
  opacity: 0.85;
}
.result-weakness__list {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 10px;
}
.result-weakness__item {
  display: inline-flex;
  flex-direction: column;
  line-height: 1.4;
}
.result-weakness__en {
  font-size: var(--text-xs);
  color: var(--color-muted);
  opacity: 0.85;
}

/* 首页源码里的静态介绍：给不执行脚本的爬虫读。能跑脚本时隐藏，避免应用加载前闪一下；
   脚本真没跑起来时，按一篇正常文章显示。 */
.js .seo-static { display: none; }
.seo-static { max-width: 720px; margin: 0 auto; padding: 24px 16px 48px; line-height: 1.8; color: var(--color-text); }
.seo-static h1 { font-size: 1.6rem; line-height: 1.4; margin: 0 0 12px; }
.seo-static h2 { font-size: 1.15rem; margin: 24px 0 6px; }
.seo-static p, .seo-static li { color: var(--color-text-light); }

/* 意见反馈页 */
.fb-card { max-width: 680px; margin: 0 auto; background: var(--color-card); border-radius: var(--radius-lg, 16px);
  padding: var(--space-lg); box-shadow: 0 2px 8px rgba(0,0,0,0.06); }
.fb-title { margin: 0 0 var(--space-sm); font-size: 1.35rem; }
.fb-lead { margin: 0 0 var(--space-md); color: var(--color-text-light); line-height: 1.8; }
.fb-h { margin: var(--space-lg) 0 var(--space-sm); font-size: 1rem; }
.fb-list { list-style: decimal; margin: 0; padding-left: 1.4em; color: var(--color-text-light); line-height: 1.9; font-size: var(--text-sm); }
.fb-tpl { margin-top: var(--space-lg); border: 1px solid var(--color-border); border-radius: var(--radius-md); overflow: hidden; }
.fb-tpl__head { display: flex; align-items: center; justify-content: space-between; gap: var(--space-sm); flex-wrap: wrap;
  padding: var(--space-sm) var(--space-md); background: var(--color-bg); font-size: var(--text-sm); font-weight: 600; }
.fb-tpl__body { margin: 0; padding: var(--space-md); font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: var(--text-xs); line-height: 1.8; white-space: pre-wrap; word-break: break-word; color: var(--color-text); }
.fb-note { margin: 0; padding: 0 var(--space-md) var(--space-md); font-size: var(--text-xs); color: var(--color-muted); }
@media (max-width: 720px) { .fb-card { padding: var(--space-md); } }

/* 添加到桌面：学习地图顶部的提示卡 + 引导页 */
.install-hint { display: flex; align-items: center; gap: var(--space-sm); margin-bottom: var(--space-md);
  padding: var(--space-sm) var(--space-sm) var(--space-sm) var(--space-md); background: var(--color-card);
  border: 2px solid var(--color-primary); border-radius: var(--radius-lg); }
.install-hint__icon { font-size: 1.6rem; flex: none; }
.install-hint__text { flex: 1; min-width: 0; display: flex; flex-direction: column; line-height: 1.4; }
.install-hint__text strong { font-size: var(--text-sm); }
.install-hint__text span { font-size: var(--text-xs); color: var(--color-text-light); }
.install-hint__go { flex: none; padding: 6px 16px; font-size: var(--text-sm); }
.install-hint__close { flex: none; border: none; background: none; color: var(--color-muted); font-size: 1rem;
  width: 32px; height: 32px; border-radius: 50%; cursor: pointer; }
.install-hint__close:hover { background: var(--color-bg); }
.inst-onetap { display: flex; flex-direction: column; align-items: flex-start; gap: 6px; margin: 0 0 var(--space-md); }
.inst-onetap[hidden] { display: none; }
.inst-guide { border: 1px solid var(--color-border); border-radius: var(--radius-md); margin-top: var(--space-sm); background: var(--color-card); }
.inst-guide--mine { border: 2px solid var(--color-primary); }
.inst-guide summary { cursor: pointer; padding: var(--space-sm) var(--space-md); font-weight: 800; display: flex; align-items: center; gap: var(--space-sm); }
.inst-mine { font-size: var(--text-xs); font-weight: 700; color: #fff; background: var(--color-primary); border-radius: 999px; padding: 1px 10px; }
.inst-steps { list-style: decimal; margin: 0; padding: 0 var(--space-md) var(--space-sm) calc(var(--space-md) + 1.4em);
  line-height: 1.9; font-size: var(--text-sm); }
.inst-note { display: block; margin: 0; padding: 0 var(--space-md) var(--space-sm); font-size: var(--text-xs); line-height: 1.8; color: var(--color-muted); }
.inst-onetap .inst-note { padding: 0; }
.inst-warn { margin: 0 var(--space-md) var(--space-md); padding: var(--space-sm) var(--space-md); border-radius: var(--radius-md);
  background: #FFF6E0; color: #6B4E00; font-size: var(--text-xs); line-height: 1.8; }
.inst-done { margin: 0 0 var(--space-md); padding: var(--space-sm) var(--space-md); border-radius: var(--radius-md);
  background: #EEF8E4; color: #2F6D00; font-size: var(--text-sm); }
@media (prefers-color-scheme: dark) {
  .inst-warn { background: #3A3218; color: #F3DE9A; }
  .inst-done { background: #1F3312; color: #BFE6A0; }
}
.inst-url { white-space: nowrap; }
@media (max-width: 400px) { .install-hint__icon { display: none; } .install-hint { gap: 6px; padding-left: var(--space-sm); } .install-hint__go { padding: 6px 12px; } .install-hint__close { width: 26px; } }

/* 改写题的原句：从题目说明里拆出来单独成卡，学生先看清要改写哪句话 */
.question-source { display: flex; gap: var(--space-sm); align-items: baseline; margin-top: var(--space-sm);
  padding: var(--space-sm) var(--space-md); border-radius: 0 var(--radius-md) var(--radius-md) 0;
  background: var(--color-bg); border-left: 4px solid var(--color-secondary); }
.question-source__label { flex: none; font-size: var(--text-xs); font-weight: 800; color: var(--color-secondary);
  border: 1.5px solid currentColor; border-radius: 6px; padding: 0 6px; line-height: 1.6; }
.question-source__text { font-size: var(--text-base); line-height: 1.7; color: var(--color-text); }

/* 多空填空题答错：填错的空后面紧跟正确答案；反馈里逐空列出 */
.fill-fix { display: inline-block; margin: 0 6px 0 4px; padding: 1px 10px; border-radius: 10px;
  background: rgba(88, 204, 2, 0.14); color: var(--color-primary-dark); font-weight: 700; font-size: 0.92em; line-height: 1.6; }
.fill-fix::before { content: "→ "; font-weight: 400; }
.fb-blanks { list-style: none; margin: 6px 0 0; padding: 0; display: flex; flex-direction: column; gap: 4px; }
.fb-blank { display: flex; flex-wrap: wrap; align-items: baseline; gap: 2px 10px; font-weight: 400; }
.fb-blank__no { font-size: 0.85em; opacity: 0.85; min-width: 3.4em; }
.fb-blank__ans { font-weight: 800; }
.fb-blank__alt { font-size: 0.85em; opacity: 0.9; }
.fb-blank__mark { font-size: 0.85em; }
.fb-blank--ok .fb-blank__ans { opacity: 0.85; }
@media (prefers-color-scheme: dark) { .fill-fix { color: #8EE000; background: rgba(88, 204, 2, 0.2); } }

/* 语法小贴士：排成「标题 + 要点 + 例句 + 易错」，分节多的折叠起来（js/tipFormat.js） */
.tip-card { border-left: 4px solid var(--color-warning); background: rgba(255, 200, 0, 0.06); }
.tip-card__label { font-weight: 700; margin-bottom: var(--space-sm); }
.tip-body { font-size: var(--text-sm); line-height: 1.75; color: var(--color-text); display: flex; flex-direction: column; gap: 8px; }
.tip-title { font-weight: 800; font-size: var(--text-base); }
.tip-lead { margin: 0; color: var(--color-text-light); }
.tip-sec { background: var(--color-card); border: 1px solid var(--color-border); border-radius: var(--radius-md); padding: 8px 12px; }
.tip-h { font-weight: 700; cursor: default; }
details.tip-sec > summary.tip-h { cursor: pointer; list-style: none; display: flex; align-items: center; gap: 6px; }
details.tip-sec > summary.tip-h::-webkit-details-marker { display: none; }
details.tip-sec > summary.tip-h::before { content: "▸"; color: var(--color-text-light); transition: transform 0.15s; }
details.tip-sec[open] > summary.tip-h::before { transform: rotate(90deg); }
.tip-list { list-style: none; margin: 6px 0 0; padding: 0; display: flex; flex-direction: column; gap: 4px; }
.tip-list li { position: relative; padding-left: 14px; color: var(--color-text-light); overflow-wrap: anywhere; }
.tip-list li::before { content: "·"; position: absolute; left: 3px; font-weight: 800; }
.tip-list li.tip-p { padding-left: 0; } .tip-list li.tip-p::before { content: none; }
.tip-list li.tip-ex { color: var(--color-text); font-family: var(--font-sans); background: rgba(28, 176, 246, 0.07); border-radius: 6px; padding: 3px 8px 3px 24px; }
.tip-list li.tip-ex::before { content: "例"; left: 6px; font-size: 0.8em; font-weight: 700; color: var(--color-secondary); top: 5px; }
.tip-list li.tip-ex--ok::before { content: "✔"; color: var(--color-primary-dark); }
.tip-list li.tip-ex--bad { background: rgba(255, 75, 75, 0.07); }
.tip-list li.tip-ex--bad s { text-decoration-color: rgba(255, 75, 75, 0.7); color: var(--color-text-light); }
.tip-fix { color: var(--color-primary-dark); font-weight: 600; }
.tip-list li.tip-ex--bad::before { content: "✘"; color: var(--color-danger); }
.tip-list li.tip-warn { background: rgba(255, 200, 0, 0.12); border-radius: 6px; padding: 3px 8px 3px 24px; color: var(--color-text); }
.tip-list li.tip-warn::before { content: "⚠"; left: 6px; font-size: 0.85em; top: 3px; }

/* 选项是整句时单列显示 */
.choices-grid--single { grid-template-columns: 1fr; }
.choices-grid--single .choice-btn { text-align: left; }
/* 发现页：答错的提示，回原文再找一找 */
.discover-nudge { margin-top: var(--space-sm); padding: 8px 12px; border-radius: var(--radius-md); background: rgba(255, 200, 0, 0.12); font-size: var(--text-sm); line-height: 1.7; }
/* 小贴士在发现题做完前折叠 */
details.tip-card > summary.tip-card__label { cursor: pointer; list-style: none; }
details.tip-card > summary.tip-card__label::-webkit-details-marker { display: none; }
details.tip-card:not([open]) > summary.tip-card__label { margin-bottom: 0; }
.tip-card__wait { font-weight: 400; font-size: var(--text-xs); color: var(--color-text-light); margin-left: 6px; }
/* 答对后「为什么？」 */
.feedback-banner__why { margin-top: var(--space-sm); background: rgba(255, 255, 255, 0.22); color: inherit; border: 1px solid rgba(255, 255, 255, 0.5); border-radius: 999px; padding: 4px 14px; font: inherit; font-size: var(--text-sm); cursor: pointer; }
/* 写作：7 分写法、参考句 */
.mission-upgrade { margin-top: 4px; font-size: var(--text-sm); line-height: 1.6; background: rgba(28, 176, 246, 0.07); border-radius: 6px; padding: 4px 8px; }
.mission-upgrade__tag { font-size: var(--text-xs); font-weight: 700; color: var(--color-secondary); margin-right: 6px; }
.mission-ref__line { font-size: var(--text-sm); line-height: 1.7; padding: 6px 0; border-top: 1px dashed var(--color-border); }