/* ===================================================================
 * components.css · 组件层 (通用 UI 组件)
 * 全部用 var() 引用令牌,换肤时本文件不动
 * =================================================================== */

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-family: var(--font-body);
  font-weight: var(--font-weight-medium);
  line-height: 1;
  white-space: nowrap;
  border: var(--border-width-thin) solid transparent;
  border-radius: var(--radius-full);
  cursor: pointer;
  /* K12 热区 ≥ 48px */
  min-height: var(--tap-min);
  padding: 13px 28px;
  transition:
    transform var(--motion-duration-fast) var(--motion-easing-spring),
    box-shadow var(--motion-duration-fast) var(--motion-easing-standard),
    background var(--motion-duration-fast) var(--motion-easing-standard);
}
.btn:active { transform: scale(0.95); }

.btn--lg { padding: 16px 36px; min-height: 56px; font-size: var(--font-size-lg); }
.btn--sm { padding: 10px 20px; min-height: 44px; font-size: var(--font-size-sm); }

/* primary:暖珊瑚实色 + 白字 + 立体贴纸阴影 */
.btn--primary {
  background: var(--color-primary);
  color: var(--color-text-inverse);
  box-shadow: var(--shadow-md);
}
.btn--primary:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
}

/* secondary:薄荷青 */
.btn--secondary {
  background: var(--color-secondary);
  color: var(--color-text-inverse);
  box-shadow: var(--shadow-sm);
}

/* outline:透明 + 主色描边 */
.btn--outline {
  background: transparent;
  color: var(--color-primary);
  border-color: var(--color-primary);
}
.btn--outline:hover {
  background: var(--color-primary);
  color: var(--color-text-inverse);
}

/* ---------- 卡片 ---------- */
.card {
  background: var(--color-card);
  border: var(--border-width-thin) solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-card-pad);
  box-shadow: var(--shadow-md);
  transition:
    transform var(--motion-duration-normal) var(--motion-easing-spring),
    box-shadow var(--motion-duration-normal) var(--motion-easing-spring);
}
.card--clickable { cursor: pointer; display: block; }
.card--clickable:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
}

/* 媒体优先卡片 */
.card--media-first { padding: 0; overflow: hidden; }
.card--media-first .card__media {
  width: 100%;
  aspect-ratio: var(--ratio-card);
  background: var(--color-border);
  display: flex; align-items: center; justify-content: center;
  font-size: 3rem;
}
.card--media-first .card__body { padding: var(--space-card-pad); }

/* ---------- 标签 / 徽章 ---------- */
.tag {
  display: inline-flex; align-items: center;
  padding: 4px 14px;
  border-radius: var(--radius-full);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-medium);
  background: var(--color-secondary-soft);
  color: var(--color-secondary);
  line-height: 1.5;
}
.badge {
  display: inline-flex; align-items: center; justify-content: center;
  min-width: 22px; height: 22px; padding: 0 7px;
  border-radius: var(--radius-full);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-semibold);
  background: var(--color-secondary);
  color: var(--color-text-inverse);
}

/* ---------- 顶部导航栏 ---------- */
.navbar {
  position: sticky; top: 0; z-index: 100;
  background: color-mix(in srgb, var(--color-bg) 85%, transparent);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
}
.navbar.is-scrolled {
  background: var(--color-bg);
  border-bottom-color: var(--color-border);
}
.navbar__inner {
  display: flex; align-items: center; justify-content: space-between;
  height: 56px;
}
.navbar__brand {
  font-family: var(--font-heading);
  font-size: var(--font-size-lg);
  color: var(--color-text);
}
.navbar__links { display: flex; align-items: center; gap: 24px; }
.navbar__links a {
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
}
.navbar__links a:hover,
.navbar__links a.is-active { color: var(--color-primary); opacity: 1; }

/* ---------- 区块标题 ---------- */
.section-head { margin-bottom: 32px; }
.section-head__eyebrow {
  display: inline-block;
  font-size: var(--font-size-sm);
  color: var(--color-primary);
  letter-spacing: var(--letter-spacing-wide);
  margin-bottom: 8px;
}
.section-head__title {
  font-family: var(--font-heading);
  font-size: var(--font-size-2xl);
  margin-bottom: 10px;
}
.section-head__desc {
  color: var(--color-text-secondary);
  max-width: 42ch;
  line-height: var(--line-height-normal);
}

/* ---------- 提示框 ---------- */
.callout {
  background: var(--color-primary-soft);
  border-left: 3px solid var(--color-primary);
  padding: 16px 20px;
  border-radius: var(--radius-sm);
  margin: 16px 0 24px;
}
.callout p:last-child { margin-bottom: 0; }
.callout strong { color: var(--color-primary); }

/* ---------- 底部 tab 栏 (App 风格 H5) ---------- */
.tabbar {
  position: fixed; bottom: 0; left: 0; width: 100%;
  display: flex;
  background: var(--color-card);
  box-shadow: 0 -2px 0 rgba(61, 44, 35, 0.08);
  padding-bottom: env(safe-area-inset-bottom);
  z-index: 90;
}
.tabbar__item {
  flex: 1;
  display: flex; flex-direction: column; align-items: center; gap: 2px;
  padding: 8px 0;
  min-height: var(--tap-min);
  color: var(--color-text-muted);
  font-size: var(--font-size-xs);
}
.tabbar__item.is-active { color: var(--color-primary); }
.tabbar__icon { font-size: 1.4rem; line-height: 1; }

/* ============================================================
 * 多页面共用组件 · 以下为内页通用结构
 * ============================================================ */

/* ---------- App 主容器:留出顶栏和底栏空间 ---------- */
.app {
  min-height: 100vh;
  padding-top: var(--appbar-h, 56px);
  padding-bottom: calc(var(--tabbar-h, 64px) + env(safe-area-inset-bottom));
}

/* ---------- 顶部导航栏(内页) ---------- */
.appbar {
  position: fixed; top: 0; left: 0; width: 100%;
  height: var(--appbar-h, 56px);
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 var(--space-page-x);
  background: color-mix(in srgb, var(--color-bg) 90%, transparent);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  z-index: 100;
}
.appbar__title {
  font-family: var(--font-heading);
  font-size: var(--font-size-lg);
  color: var(--color-text);
}
.appbar__action {
  min-width: var(--tap-min);
  min-height: var(--tap-min);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.3rem;
  color: var(--color-text-secondary);
  cursor: pointer;
}

/* ---------- 页面主体(带内边距) ---------- */
.page { padding: 16px 0 8px; }
.page__section { margin-bottom: 24px; }
.page__section:last-child { margin-bottom: 0; }

/* ---------- 统计卡(仪表盘用) ---------- */
.stat-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
}
.stat-card {
  background: var(--color-card);
  border: var(--border-width-thin) solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 14px 10px;
  text-align: center;
  box-shadow: var(--shadow-sm);
}
.stat-card__num {
  font-family: var(--font-heading);
  font-size: var(--font-size-xl);
  color: var(--color-primary);
  line-height: 1;
  margin-bottom: 4px;
}
.stat-card__num--mint { color: var(--color-secondary); }
.stat-card__num--yellow { color: var(--color-warning); }
.stat-card__label {
  font-size: var(--font-size-xs);
  color: var(--color-text-muted);
}

/* ---------- 列表项(设置/菜单用) ---------- */
.list-row {
  display: flex; align-items: center; gap: 14px;
  padding: 14px var(--space-card-pad);
  background: var(--color-card);
  border-bottom: 1px solid var(--color-border);
  min-height: var(--tap-min);
  cursor: pointer;
}
.list-row:first-child { border-top-left-radius: var(--radius-md); border-top-right-radius: var(--radius-md); }
.list-row:last-child { border-bottom-left-radius: var(--radius-md); border-bottom-right-radius: var(--radius-md); border-bottom: none; }
.list-row:active { background: var(--color-primary-soft); }
.list-row__icon {
  width: 40px; height: 40px;
  flex-shrink: 0;
  border-radius: var(--radius-sm);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.3rem;
  background: var(--color-primary-soft);
}
.list-row__icon--mint { background: var(--color-secondary-soft); }
.list-row__icon--yellow { background: color-mix(in srgb, var(--color-accent-1) 30%, transparent); }
.list-row__icon--peach { background: color-mix(in srgb, var(--color-accent-3) 45%, transparent); }
.list-row__icon--lav { background: color-mix(in srgb, var(--color-accent-4) 45%, transparent); }
.list-row__main { flex: 1; min-width: 0; }
.list-row__title { font-size: var(--font-size-base); }
.list-row__sub { font-size: var(--font-size-xs); color: var(--color-text-muted); margin-top: 2px; }
.list-row__arrow { color: var(--color-text-muted); font-size: 1.1rem; }

/* 列表分组容器(圆角卡片) */
.list-group {
  border: var(--border-width-thin) solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}
.list-group + .list-group { margin-top: 16px; }
.list-group__header {
  padding: 10px var(--space-card-pad) 6px;
  font-size: var(--font-size-xs);
  color: var(--color-text-muted);
  font-weight: var(--font-weight-medium);
}

/* ---------- 章节小标题 ---------- */
.page-title {
  font-family: var(--font-heading);
  font-size: var(--font-size-xl);
  margin-bottom: 4px;
}
.page-subtitle {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  margin-bottom: 20px;
}

/* ---------- 徽章(进度/数量) ---------- */
.chip {
  display: inline-flex; align-items: center; gap: 4px;
  padding: 3px 10px;
  border-radius: var(--radius-full);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-medium);
  background: var(--color-primary-soft);
  color: var(--color-primary);
}
.chip--mint { background: var(--color-secondary-soft); color: var(--color-secondary); }
.chip--gray { background: color-mix(in srgb, var(--color-text-muted) 16%, transparent); color: var(--color-text-secondary); }

/* ============================================================
 * AI 模块样式 · 凸起Tab + AI页面通用组件
 * ============================================================ */

/* ---------- 底部Tab中间凸起的AI按钮 ---------- */
.tabbar--with-ai { position: relative; }
.tabbar__ai-btn {
  position: absolute;
  left: 50%; top: -22px;
  transform: translateX(-50%);
  width: 56px; height: 56px;
  border-radius: var(--radius-full);
  background: linear-gradient(135deg, var(--color-primary), color-mix(in srgb, var(--color-primary) 60%, var(--color-accent-1)));
  display: flex; align-items: center; justify-content: center;
  font-size: 1.6rem;
  box-shadow: 0 4px 12px color-mix(in srgb, var(--color-primary) 40%, transparent);
  z-index: 91;
  text-decoration: none;
  border: 3px solid var(--color-bg);
  animation: aiPulse 2.5s ease-in-out infinite;
}
@keyframes aiPulse {
  0%, 100% { box-shadow: 0 4px 12px color-mix(in srgb, var(--color-primary) 40%, transparent); }
  50% { box-shadow: 0 6px 20px color-mix(in srgb, var(--color-primary) 60%, transparent), 0 0 0 6px color-mix(in srgb, var(--color-primary) 12%, transparent); }
}
@media (prefers-reduced-motion: reduce) { .tabbar__ai-btn { animation: none; } }
/* 凸起按钮占据中间位置,两侧Tab各占一半 */
.tabbar--with-ai .tabbar__item { flex: 1; }
.tabbar--with-ai .tabbar__ai-spacer { flex: 0 0 56px; }

/* ---------- AI功能卡(大厅用) ---------- */
.ai-feature {
  display: flex; align-items: center; gap: 14px;
  background: var(--color-card);
  border: var(--border-width-thin) solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 16px;
  box-shadow: var(--shadow-sm);
  text-decoration: none;
  transition: transform var(--motion-duration-fast) var(--motion-easing-spring);
  position: relative;
  overflow: hidden;
}
.ai-feature:active { transform: scale(0.98); }
.ai-feature__icon {
  width: 52px; height: 52px; flex-shrink: 0;
  border-radius: var(--radius-md);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.6rem;
  box-shadow: var(--shadow-sm);
}
.ai-feature__icon--coral { background: linear-gradient(135deg, color-mix(in srgb, var(--color-primary) 24%, transparent), color-mix(in srgb, var(--color-accent-3) 30%, transparent)); }
.ai-feature__icon--mint  { background: linear-gradient(135deg, color-mix(in srgb, var(--color-secondary) 26%, transparent), color-mix(in srgb, var(--color-accent-2) 30%, transparent)); }
.ai-feature__icon--yellow{ background: linear-gradient(135deg, color-mix(in srgb, var(--color-accent-1) 42%, transparent), color-mix(in srgb, var(--color-warning) 22%, transparent)); }
.ai-feature__icon--lav   { background: linear-gradient(135deg, color-mix(in srgb, var(--color-accent-4) 50%, transparent), color-mix(in srgb, var(--color-info) 20%, transparent)); }
.ai-feature__main { flex: 1; min-width: 0; }
.ai-feature__title { font-family: var(--font-heading); font-size: var(--font-size-base); margin-bottom: 3px; }
.ai-feature__desc { font-size: var(--font-size-xs); color: var(--color-text-secondary); line-height: var(--line-height-normal); }
.ai-feature__tag {
  position: absolute; top: 10px; right: 12px;
  padding: 2px 8px; border-radius: var(--radius-full);
  background: color-mix(in srgb, var(--color-accent-1) 40%, transparent);
  color: var(--color-text); font-size: 10px; font-weight: var(--font-weight-bold);
}
.ai-feature__go { color: var(--color-text-muted); font-size: 1.2rem; }

/* ---------- AI聊天气泡 ---------- */
.chat-list { display: flex; flex-direction: column; gap: 14px; padding-bottom: 20px; }
.chat-bubble {
  max-width: 82%;
  padding: 12px 16px;
  border-radius: var(--radius-lg);
  font-size: var(--font-size-sm);
  line-height: var(--line-height-normal);
  animation: bubbleIn var(--motion-duration-normal) var(--motion-easing-spring);
}
@keyframes bubbleIn { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: translateY(0); } }
.chat-bubble--ai {
  align-self: flex-start;
  background: var(--color-card);
  border: var(--border-width-thin) solid var(--color-border);
  border-bottom-left-radius: var(--radius-sm);
  box-shadow: var(--shadow-sm);
}
.chat-bubble--user {
  align-self: flex-end;
  background: var(--color-primary);
  color: var(--color-text-inverse);
  border-bottom-right-radius: var(--radius-sm);
}
.chat-bubble__avatar { font-size: 1.1rem; margin-bottom: 4px; }
.chat-bubble__time { font-size: 10px; color: var(--color-text-muted); margin-top: 4px; }

/* ---------- AI底部输入栏 ---------- */
.chat-input-bar {
  position: fixed; bottom: var(--tabbar-h, 64px); left: 0; width: 100%;
  display: flex; align-items: center; gap: 8px;
  padding: 10px var(--space-page-x) calc(10px + env(safe-area-inset-bottom));
  background: var(--color-card);
  border-top: 1px solid var(--color-border);
  z-index: 89;
}
.chat-input {
  flex: 1;
  border: var(--border-width-thin) solid var(--color-border);
  border-radius: var(--radius-full);
  padding: 10px 18px;
  font-size: var(--font-size-sm);
  background: var(--color-bg);
  color: var(--color-text);
  min-height: var(--tap-min);
}
.chat-input:focus { outline: none; border-color: var(--color-primary); }
.chat-send {
  width: var(--tap-min); height: var(--tap-min);
  border-radius: var(--radius-full);
  background: var(--color-primary); color: var(--color-text-inverse);
  border: none; font-size: 1.2rem; cursor: pointer;
  flex-shrink: 0;
  box-shadow: var(--shadow-sm);
}

/* ---------- 评分环(AI打分用) ---------- */
.score-pods { display: flex; justify-content: space-around; margin-bottom: 20px; }
.score-pod { text-align: center; }
.score-pod__num { font-family: var(--font-heading); font-size: var(--font-size-2xl); line-height: 1; }
.score-pod__num--good { color: var(--color-success); }
.score-pod__num--mid { color: var(--color-warning); }
.score-pod__label { font-size: var(--font-size-xs); color: var(--color-text-muted); margin-top: 4px; }

/* ============================================================
 * 全站统一导航 · 悬浮顶栏 + 5格底部Tab (V2 架构)
 * 顶栏: 品牌 | 🔧工具 ✨AI 👤我的
 * 底栏: 学习 单词 课文 阅读 课程
 * ============================================================ */

/* ---------- 悬浮顶部栏(全站统一) ---------- */
.topbar {
  position: fixed; top: 0; left: 0; width: 100%;
  z-index: 100;
  display: flex; align-items: center; justify-content: space-between;
  flex-wrap: nowrap;                          /* ★ 禁止换行,防止挤到第二行 */
  gap: 8px;
  padding: 8px var(--space-page-x);
  padding-top: calc(8px + env(safe-area-inset-top));
  background: color-mix(in srgb, var(--color-bg) 88%, transparent);
  backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--motion-duration-normal) var(--motion-easing-standard),
              background var(--motion-duration-normal) var(--motion-easing-standard);
}
.topbar.is-scrolled {
  background: var(--color-bg);
  border-bottom-color: var(--color-border);
}
.topbar__left {
  display: flex; align-items: center; gap: 8px;
  text-decoration: none;
}
.topbar__logo {
  width: 32px; height: 32px; border-radius: var(--radius-sm);
  background: linear-gradient(135deg, var(--color-primary), color-mix(in srgb, var(--color-primary) 60%, var(--color-accent-3)));
  display: flex; align-items: center; justify-content: center; font-size: 1rem;
}
.topbar__brand {
  font-family: var(--font-heading); font-size: var(--font-size-base);
  color: var(--color-text);
}
.topbar__back {
  min-width: 36px; min-height: 36px;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.5rem; color: var(--color-text);
  text-decoration: none;
}
.topbar__title {
  font-family: var(--font-heading); font-size: var(--font-size-base); color: var(--color-text);
  flex: 1 1 auto; min-width: 0; text-align: center;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.topbar__left { flex-shrink: 0; }
.topbar__right { display: flex; align-items: center; gap: 2px; flex-shrink: 0; }
/* 右侧图标:只保留emoji,去掉文字标签,紧凑常驻 */
.topbar__icon {
  width: 38px; height: 38px;
  display: flex; align-items: center; justify-content: center;
  text-decoration: none;
  color: var(--color-text-secondary);
  border-radius: var(--radius-sm);
  transition: background var(--motion-duration-fast) var(--motion-easing-standard), transform var(--motion-duration-fast) var(--motion-easing-spring);
}
.topbar__icon:active { background: var(--color-primary-soft); transform: scale(0.92); }
.topbar__icon-emoji { font-size: 1.25rem; line-height: 1; }

/* "我的"头像按钮(用户头像,圆形带渐变背景,专业登录态) */
.topbar__icon--avatar {
  width: 34px; height: 34px;
  padding: 0; overflow: hidden;
  border-radius: var(--radius-full);
  background: linear-gradient(135deg, var(--color-accent-3), color-mix(in srgb, var(--color-accent-3) 55%, var(--color-accent-1)));
  border: 2px solid var(--color-card);
  box-shadow: var(--shadow-sm);
}
.topbar__icon--avatar .topbar__icon-emoji { font-size: 1.05rem; }
.topbar__icon--avatar:active { transform: scale(0.92); }

/* AI 按钮:粉紫橙径向渐变 + 呼吸光晕(与旁边图标等大) */
.topbar__icon--ai {
  width: 34px; height: 34px;
  background: radial-gradient(circle at 30% 30%, #FF6B9D 0%, #8A5CF6 50%, #FF8C42 100%);
  color: #FFFFFF;
  border-radius: var(--radius-full);
  font-weight: var(--font-weight-bold);
  position: relative;
  box-shadow: 0 2px 8px rgba(138, 92, 246, 0.4);
  z-index: 1;
}
.topbar__icon--ai .topbar__icon-emoji { font-size: 0.85rem; }
/* 伪元素:光晕(收小扩散幅度,避免视觉过大) */
.topbar__icon--ai::before {
  content: "";
  position: absolute;
  inset: -1px;
  border-radius: var(--radius-full);
  background: radial-gradient(circle, rgba(255, 107, 157, 0.5) 0%, rgba(138, 92, 246, 0.25) 60%, transparent 100%);
  z-index: -1;
  animation: aiHalo 2.4s ease-in-out infinite;
}
.topbar__icon--ai::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: var(--radius-full);
  border: 2px solid rgba(255, 107, 157, 0.45);
  animation: aiRing 2.4s ease-out infinite;
  z-index: -1;
}
@keyframes aiHalo {
  0%, 100% { opacity: 0.4; transform: scale(1); }
  50%      { opacity: 0.85; transform: scale(1.15); }
}
@keyframes aiRing {
  0%   { opacity: 0.6; transform: scale(1); }
  100% { opacity: 0; transform: scale(1.5); }
}
@media (prefers-reduced-motion: reduce) {
  .topbar__icon--ai::before, .topbar__icon--ai::after { animation: none; }
  .topbar__icon--ai::before { opacity: 0.7; transform: scale(1.15); }
}
.topbar__icon--ai:active { transform: scale(0.92); }

/* ---------- 5格底部Tab(无凸起) ---------- */
.tabbar--v2 {
  position: fixed; bottom: 0; left: 0; width: 100%;
  display: flex;
  background: var(--color-card);
  box-shadow: 0 -2px 0 rgba(61, 44, 35, 0.06);
  padding-bottom: env(safe-area-inset-bottom);
  z-index: 90;
}
.tabbar--v2 .tabbar__item {
  flex: 1;
  display: flex; flex-direction: column; align-items: center; gap: 2px;
  padding: 8px 0;
  min-height: var(--tap-min);
  color: var(--color-text-muted);
  font-size: var(--font-size-xs);
  text-decoration: none;
}
.tabbar--v2 .tabbar__item.is-active { color: var(--color-primary); }
.tabbar--v2 .tabbar__icon { font-size: 1.3rem; line-height: 1; }

/* ---------- 课程图标(纯CSS播放键,精致美观,替代📺) ---------- */
/* 用法: <span class="ico-course"></span>  尺寸继承父级 font-size */
.ico-course {
  display: inline-block;
  width: 1em; height: 1em;
  border-radius: 30%;
  background: linear-gradient(135deg, var(--color-primary), color-mix(in srgb, var(--color-primary) 55%, var(--color-accent-1)));
  position: relative;
  vertical-align: middle;
}
.ico-course::before {
  content: "";
  position: absolute;
  left: 55%; top: 50%;
  transform: translate(-50%, -50%);
  border-style: solid;
  border-width: 0.28em 0 0.28em 0.45em;
  border-color: transparent transparent transparent var(--color-text-inverse);
}
/* 金刚区/卡片里用稍大尺寸 */
.ico-course--md { font-size: 1.3rem; }
/* 纯白播放键(用于浅色背景) */
.ico-course--ghost {
  background: color-mix(in srgb, var(--color-primary) 14%, transparent);
  border: 1.5px solid var(--color-primary);
}
.ico-course--ghost::before {
  border-color: transparent transparent transparent var(--color-primary);
}

/* 使用新顶栏时,主体留出顶部空间 */
/* 使用悬浮顶栏时:顶部已有占位div撑高度,这里只管底部留白给tabbar */
.app--topbar {
  min-height: 100vh;
  padding-bottom: calc(var(--tabbar-h, 64px) + 16px + env(safe-area-inset-bottom));
  padding-inline: var(--space-page-x);   /* ★ 统一左右边距,内容不顶屏幕边 */
  overflow-x: hidden;   /* ★ 防止任何子元素负边距撑出横向滚动 */
}
/* app--topbar 内的 container 不再重复加左右padding(避免双边距) */
.app--topbar .container {
  padding-inline: 0;
  width: 100%;
}
/* app--topbar 内的横向滚动区域:负边距抵消父级padding,实现满宽横滚 */
.app--topbar .scroll-row,
.app--topbar .course-scroll,
.app--topbar .cat-tabs,
.app--topbar .quick-q {
  margin-inline: calc(-1 * var(--space-page-x));
  padding-inline: var(--space-page-x);
}