/* ============================================================
   零零测分网 00cf.com  —  Global Design System
   ============================================================ */

/* ── 1. CSS 变量 ─────────────────────────────────────────── */
:root {
  --primary:       #6c3fc5;
  --primary-light: #8b5cf6;
  --primary-dark:  #4c1d95;
  --accent:        #06b6d4;
  --bg:            #f0f2f8;
  --bg-card:       rgba(255,255,255,0.82);
  --bg-glass:      rgba(255,255,255,0.55);
  --border:        rgba(255,255,255,0.65);
  --shadow:        0 4px 24px rgba(108,63,197,0.10);
  --shadow-hover:  0 8px 32px rgba(108,63,197,0.18);
  --text:          #1e1b4b;
  --text-muted:    #6b7280;
  --text-light:    #9ca3af;
  --radius:        14px;
  --radius-sm:     8px;
  --radius-lg:     20px;
  --header-h:      64px;
  --transition:    0.22s ease;
}

/* ── 2. Reset & Base ─────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; }

html {
  font-size: 15px;
  scroll-behavior: smooth;
}
@media (max-width: 768px) { html { font-size: 14px; } }

body {
  margin: 0;
  font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  line-height: 1.6;
}

a { color: inherit; text-decoration: none; }
a:hover { color: var(--primary); }
img { max-width: 100%; }

/* ── 3. 页面背景渐变 ─────────────────────────────────────── */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 60% at 10% -10%, rgba(139,92,246,0.13) 0%, transparent 60%),
    radial-gradient(ellipse 60% 50% at 90% 80%,  rgba(6,182,212,0.09)  0%, transparent 55%);
  pointer-events: none;
  z-index: 0;
}
body > * { position: relative; z-index: 1; }

/* ── 4. Glass 工具类 ─────────────────────────────────────── */
.glass {
  background: var(--bg-glass);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border);
}
.glass-card {
  background: var(--bg-card);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: box-shadow var(--transition), transform var(--transition);
}
.glass-card:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-2px);
}

/* ── 5. Header / 顶部导航 ────────────────────────────────── */
.site-header {
  position: sticky;
  top: 0;
  height: var(--header-h);
  background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary) 60%, var(--primary-light) 100%);
  box-shadow: 0 2px 16px rgba(76,29,149,0.25);
  z-index: 1000;
  display: flex;
  align-items: center;
}
.site-header .container {
  width: 100%;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  align-items: center;
  gap: 20px;
}

/* Logo */
.site-logo {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
  text-decoration: none;
}
.site-logo-icon {
  width: 36px; height: 36px;
  background: rgba(255,255,255,0.22);
  border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  font-size: 18px; font-weight: 800; color: #fff;
  letter-spacing: -1px;
}
.site-logo-text { color: #fff; font-size: 1.15rem; font-weight: 700; }
.site-logo-text span { font-size: 0.75rem; opacity: 0.75; display: block; font-weight: 400; }

/* 搜索框 */
.header-search {
  flex: 1;
  max-width: 480px;
  position: relative;
}
.header-search input {
  width: 100%;
  padding: 8px 16px 8px 42px;
  border-radius: 24px;
  border: none;
  background: rgba(255,255,255,0.18);
  color: #fff;
  font-size: 0.9rem;
  outline: none;
  transition: background var(--transition);
}
.header-search input::placeholder { color: rgba(255,255,255,0.65); }
.header-search input:focus { background: rgba(255,255,255,0.28); }
.header-search .search-icon {
  position: absolute; left: 14px; top: 50%; transform: translateY(-50%);
  color: rgba(255,255,255,0.75); font-size: 15px; pointer-events: none;
}

/* 顶部导航菜单 */
.header-nav {
  display: flex; align-items: center; gap: 4px;
  margin-left: auto;
}
.header-nav a {
  color: rgba(255,255,255,0.88);
  font-size: 0.88rem;
  padding: 6px 12px;
  border-radius: 8px;
  transition: background var(--transition), color var(--transition);
  white-space: nowrap;
}
.header-nav a:hover, .header-nav a.active {
  background: rgba(255,255,255,0.18);
  color: #fff;
}

/* 用户区域 */
.header-user {
  display: flex; align-items: center; gap: 10px; flex-shrink: 0;
}
.btn-login {
  padding: 6px 16px;
  border-radius: 20px;
  border: 1.5px solid rgba(255,255,255,0.65);
  background: transparent;
  color: #fff;
  font-size: 0.85rem;
  cursor: pointer;
  transition: background var(--transition);
  text-decoration: none;
  display: inline-block;
}
.btn-login:hover { background: rgba(255,255,255,0.18); color: #fff; }
.btn-register {
  padding: 6px 16px;
  border-radius: 20px;
  background: #fff;
  color: var(--primary);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: opacity var(--transition);
  text-decoration: none;
  display: inline-block;
}
.btn-register:hover { opacity: 0.88; color: var(--primary); }

/* 移动端汉堡菜单 */
.header-toggle {
  display: none;
  background: none; border: none; cursor: pointer;
  padding: 6px;
  color: #fff; font-size: 22px;
}

/* ── 6. 面包屑 ───────────────────────────────────────────── */
.breadcrumb-bar {
  background: var(--bg-glass);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid rgba(108,63,197,0.08);
  padding: 10px 0;
}
.breadcrumb {
  display: flex; align-items: center; gap: 6px;
  font-size: 0.82rem; color: var(--text-muted);
  list-style: none; margin: 0; padding: 0;
}
.breadcrumb li:not(:last-child)::after { content: "/"; margin-left: 6px; color: var(--text-light); }
.breadcrumb a { color: var(--primary); }
.breadcrumb a:hover { text-decoration: underline; }

/* ── 7. 按钮 ─────────────────────────────────────────────── */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 6px;
  padding: 8px 20px; border-radius: 10px;
  font-size: 0.88rem; font-weight: 500;
  cursor: pointer; border: none;
  transition: all var(--transition);
  text-decoration: none;
}
.btn-primary {
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  color: #fff;
  box-shadow: 0 4px 14px rgba(108,63,197,0.35);
}
.btn-primary:hover { opacity: 0.9; transform: translateY(-1px); color: #fff; }
.btn-ghost {
  background: transparent;
  border: 1.5px solid var(--primary);
  color: var(--primary);
}
.btn-ghost:hover { background: var(--primary); color: #fff; }
.btn-sm { padding: 5px 14px; font-size: 0.82rem; border-radius: 8px; }
.btn-lg { padding: 12px 32px; font-size: 1rem; border-radius: 12px; }

/* ── 8. 徽章 / 科目色 ────────────────────────────────────── */
.badge {
  display: inline-flex; align-items: center;
  padding: 3px 10px; border-radius: 20px;
  font-size: 0.75rem; font-weight: 600;
  white-space: nowrap;
}
.pb-blue   { background: rgba( 59,130,246,0.12); color: #2563eb; }
.pb-green  { background: rgba( 34,197, 94,0.12); color: #16a34a; }
.pb-purple { background: rgba(139, 92,246,0.12); color: #7c3aed; }
.pb-amber  { background: rgba(245,158, 11,0.12); color: #d97706; }
.pb-red    { background: rgba(239, 68, 68,0.12); color: #dc2626; }
.pb-teal   { background: rgba(  6,182,212,0.12); color: #0891b2; }
.pb-pink   { background: rgba(236, 72,153,0.12); color: #db2777; }
.pb-orange { background: rgba(249,115, 22,0.12); color: #ea580c; }

/* 年级标签 */
.grade-tag {
  display: inline-block;
  padding: 2px 8px; border-radius: 6px;
  font-size: 0.72rem; font-weight: 600;
  background: rgba(108,63,197,0.10); color: var(--primary);
}

/* ── 9. ptag 知识点标签 ──────────────────────────────────── */
.ptag {
  display: inline-flex; align-items: center;
  padding: 3px 10px; border-radius: 20px;
  font-size: 0.75rem;
  background: rgba(108,63,197,0.08);
  color: var(--primary);
  border: 1px solid rgba(108,63,197,0.15);
  transition: background var(--transition);
}
.ptag:hover { background: rgba(108,63,197,0.16); cursor: pointer; }
.ptag-wrap { display: flex; flex-wrap: wrap; gap: 6px; }

/* ── 10. 难度星级 ────────────────────────────────────────── */
.difficulty {
  display: inline-flex; align-items: center; gap: 2px;
  font-size: 0.78rem; color: var(--text-muted);
}
.difficulty .star { color: #f59e0b; }
.difficulty .star.empty { color: #d1d5db; }

/* ── 11. 分页 ────────────────────────────────────────────── */
.pagination {
  display: flex; align-items: center; gap: 6px;
  list-style: none; margin: 0; padding: 0;
}
.pagination .page-item .page-link {
  display: flex; align-items: center; justify-content: center;
  width: 36px; height: 36px; border-radius: 8px;
  border: 1px solid rgba(108,63,197,0.18);
  color: var(--text); font-size: 0.88rem;
  transition: all var(--transition);
  text-decoration: none;
}
.pagination .page-item.active .page-link {
  background: var(--primary); border-color: var(--primary); color: #fff;
}
.pagination .page-item .page-link:hover {
  background: rgba(108,63,197,0.08);
}

/* ── 12. Footer ──────────────────────────────────────────── */
.site-footer {
  background: linear-gradient(135deg, #1e1b4b 0%, #2d1b69 100%);
  color: rgba(255,255,255,0.75);
  padding: 48px 0 24px;
  margin-top: 60px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 20px;
}
.footer-col h4 {
  color: #fff; font-size: 0.95rem; font-weight: 600;
  margin: 0 0 16px; padding-bottom: 8px;
  border-bottom: 1px solid rgba(255,255,255,0.12);
}
.footer-col p { font-size: 0.85rem; line-height: 1.7; margin: 0 0 12px; }
.footer-col ul { list-style: none; margin: 0; padding: 0; }
.footer-col ul li { margin-bottom: 8px; }
.footer-col ul li a { font-size: 0.85rem; color: rgba(255,255,255,0.65); transition: color var(--transition); }
.footer-col ul li a:hover { color: #fff; }
.footer-brand { font-size: 1.2rem; font-weight: 700; color: #fff; margin-bottom: 12px; }
.footer-divider {
  max-width: 1280px; margin: 24px auto 0;
  padding: 16px 20px 0;
  border-top: 1px solid rgba(255,255,255,0.10);
  display: flex; align-items: center; justify-content: space-between;
  font-size: 0.8rem; color: rgba(255,255,255,0.45);
}
.footer-links { display: flex; gap: 16px; }
.footer-links a { color: rgba(255,255,255,0.45); font-size: 0.8rem; }
.footer-links a:hover { color: rgba(255,255,255,0.75); }

/* ── 13. 公共布局工具 ────────────────────────────────────── */
.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 20px;
}
.page-wrap { padding: 28px 0 60px; }
.two-col {
  display: grid;
  grid-template-columns: 260px 1fr;
  gap: 24px;
  align-items: start;
}
.section-title {
  font-size: 1.15rem; font-weight: 700;
  color: var(--text); margin: 0 0 18px;
  display: flex; align-items: center; gap: 8px;
}
.section-title::before {
  content: "";
  display: block; width: 4px; height: 18px;
  border-radius: 4px;
  background: linear-gradient(180deg, var(--primary), var(--primary-light));
}

/* ── 14. 侧边栏 ──────────────────────────────────────────── */
.sidebar { display: flex; flex-direction: column; gap: 16px; }
.side-card {
  background: var(--bg-card);
  backdrop-filter: blur(16px);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 18px;
}
.side-card-title {
  font-size: 0.88rem; font-weight: 600;
  color: var(--text); margin: 0 0 12px;
  display: flex; align-items: center; justify-content: space-between;
}
.side-filter-group { margin-bottom: 14px; }
.side-filter-label {
  font-size: 0.78rem; color: var(--text-muted);
  margin-bottom: 6px; font-weight: 500;
}
.filter-chips { display: flex; flex-wrap: wrap; gap: 6px; }
.filter-chip {
  padding: 4px 12px; border-radius: 20px; border: 1.5px solid rgba(108,63,197,0.18);
  background: transparent; color: var(--text-muted);
  font-size: 0.78rem; cursor: pointer;
  transition: all var(--transition);
}
.filter-chip:hover, .filter-chip.active {
  background: var(--primary); border-color: var(--primary);
  color: #fff;
}

/* ── 15. 题目卡片（列表页） ──────────────────────────────── */
.quiz-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 18px 20px;
  display: flex; flex-direction: column; gap: 10px;
  transition: box-shadow var(--transition), transform var(--transition);
  text-decoration: none; color: inherit;
}
.quiz-card:hover {
  box-shadow: var(--shadow-hover); transform: translateY(-2px); color: inherit;
}
.quiz-card-header {
  display: flex; align-items: center; gap: 8px; flex-wrap: wrap;
}
.quiz-card-title {
  font-size: 0.95rem; font-weight: 600; line-height: 1.5;
  color: var(--text); margin: 0;
  display: -webkit-box; -webkit-line-clamp: 2;
  -webkit-box-orient: vertical; overflow: hidden;
}
.quiz-card-meta {
  display: flex; align-items: center; gap: 12px;
  font-size: 0.78rem; color: var(--text-muted);
}
.quiz-card-meta span { display: flex; align-items: center; gap: 4px; }
.quiz-card-footer {
  display: flex; align-items: center; justify-content: space-between;
  padding-top: 10px; border-top: 1px solid rgba(108,63,197,0.07);
}

/* 卡片网格 */
.quiz-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 16px;
}
.quiz-list { display: flex; flex-direction: column; gap: 12px; }

/* ── 16. 题目详情页 ──────────────────────────────────────── */
.question-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 24px;
  margin-bottom: 16px;
}
.question-number {
  font-size: 0.78rem; font-weight: 700;
  color: var(--primary); letter-spacing: 0.03em;
  margin-bottom: 8px;
}
.question-text {
  font-size: 0.95rem; line-height: 1.8;
  color: var(--text); margin-bottom: 16px;
}
.question-options { display: flex; flex-direction: column; gap: 8px; }
.option-item {
  display: flex; align-items: flex-start; gap: 10px;
  padding: 10px 14px; border-radius: 10px;
  border: 1.5px solid rgba(108,63,197,0.14);
  cursor: pointer; transition: all var(--transition);
  font-size: 0.9rem;
}
.option-item:hover { background: rgba(108,63,197,0.06); border-color: var(--primary-light); }
.option-item.selected { background: rgba(108,63,197,0.1); border-color: var(--primary); }
.option-item.correct  { background: rgba(34,197,94,0.1);  border-color: #16a34a; }
.option-item.wrong    { background: rgba(239,68,68,0.1);  border-color: #dc2626; }
.option-label {
  width: 22px; height: 22px; border-radius: 6px;
  background: rgba(108,63,197,0.1); color: var(--primary);
  font-weight: 700; font-size: 0.8rem;
  display: flex; align-items: center; justify-content: center; flex-shrink: 0;
}

/* 答案解析区 */
.answer-reveal {
  margin-top: 16px; padding: 14px 18px;
  border-radius: 10px;
  background: rgba(34,197,94,0.07);
  border-left: 4px solid #16a34a;
  font-size: 0.88rem; line-height: 1.7;
}
.answer-reveal .answer-label {
  font-weight: 700; color: #16a34a; margin-bottom: 6px;
}

/* 答题 action bar */
.detail-action-bar {
  position: sticky; bottom: 0;
  background: rgba(255,255,255,0.9);
  backdrop-filter: blur(12px);
  border-top: 1px solid rgba(108,63,197,0.10);
  padding: 12px 0;
  z-index: 100;
}
.action-bar-inner {
  max-width: 1280px; margin: 0 auto; padding: 0 20px;
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
}
.progress-mini {
  display: flex; align-items: center; gap: 10px; font-size: 0.82rem; color: var(--text-muted);
}
.progress-mini .progress-bar-wrap {
  width: 120px; height: 6px; border-radius: 99px;
  background: rgba(108,63,197,0.12);
  overflow: hidden;
}
.progress-mini .progress-bar-fill {
  height: 100%; border-radius: 99px;
  background: linear-gradient(90deg, var(--primary), var(--primary-light));
  transition: width 0.4s ease;
}

/* ── 17. Hero Banner（首页） ─────────────────────────────── */
.hero {
  background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary) 50%, var(--accent) 100%);
  padding: 60px 20px 80px;
  text-align: center;
  position: relative; overflow: hidden;
}
.hero::before {
  content: "";
  position: absolute; inset: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.04'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}
.hero-content { position: relative; max-width: 700px; margin: 0 auto; }
.hero h1 { color: #fff; font-size: 2.2rem; font-weight: 800; margin: 0 0 12px; line-height: 1.3; }
.hero p { color: rgba(255,255,255,0.82); font-size: 1.05rem; margin: 0 0 32px; }
.hero-search {
  display: flex; max-width: 560px; margin: 0 auto;
  background: rgba(255,255,255,0.15);
  backdrop-filter: blur(16px);
  border-radius: 14px; border: 1px solid rgba(255,255,255,0.35);
  padding: 6px 6px 6px 20px; gap: 8px; align-items: center;
}
.hero-search input {
  flex: 1; background: none; border: none; outline: none;
  color: #fff; font-size: 0.95rem;
}
.hero-search input::placeholder { color: rgba(255,255,255,0.65); }
.hero-search .btn { flex-shrink: 0; background: #fff; color: var(--primary); font-weight: 700; }
.hero-stats {
  display: flex; justify-content: center; gap: 40px;
  margin-top: 40px; flex-wrap: wrap;
}
.hero-stat { text-align: center; }
.hero-stat .num { font-size: 1.8rem; font-weight: 800; color: #fff; }
.hero-stat .label { font-size: 0.82rem; color: rgba(255,255,255,0.7); margin-top: 2px; }

/* 科目卡片（首页） */
.subject-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(130px, 1fr));
  gap: 14px;
}
.subject-card {
  display: flex; flex-direction: column; align-items: center; gap: 8px;
  padding: 18px 12px;
  border-radius: var(--radius);
  cursor: pointer;
  transition: all var(--transition);
  text-decoration: none; color: inherit;
}
.subject-card:hover { transform: translateY(-3px); color: inherit; }
.subject-icon {
  width: 48px; height: 48px; border-radius: 14px;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.5rem;
}
.subject-name { font-size: 0.88rem; font-weight: 600; color: var(--text); }
.subject-count { font-size: 0.75rem; color: var(--text-muted); }

/* ── 18. sr-only ─────────────────────────────────────────── */
.sr-only {
  position: absolute; width: 1px; height: 1px;
  padding: 0; margin: -1px; overflow: hidden;
  clip: rect(0,0,0,0); white-space: nowrap; border: 0;
}

/* ── 19. 移动端底部导航栏 ────────────────────────────────── */
.mobile-bottom-nav {
  display: none;
  position: fixed; bottom: 0; left: 0; right: 0;
  height: 56px;
  background: rgba(255,255,255,0.96);
  backdrop-filter: blur(16px);
  border-top: 1px solid rgba(108,63,197,0.12);
  z-index: 999;
  box-shadow: 0 -4px 20px rgba(108,63,197,0.08);
}
.mobile-bottom-nav .nav-items {
  display: flex; height: 100%;
}
.mobile-bottom-nav .nav-item {
  flex: 1; display: flex; flex-direction: column;
  align-items: center; justify-content: center; gap: 3px;
  text-decoration: none; color: var(--text-muted);
  font-size: 0.65rem; font-weight: 500;
  transition: color var(--transition);
  position: relative;
}
.mobile-bottom-nav .nav-item .icon { font-size: 1.3rem; line-height: 1; }
.mobile-bottom-nav .nav-item.active { color: var(--primary); }
.mobile-bottom-nav .nav-item.active::before {
  content: "";
  position: absolute; top: 0; left: 50%; transform: translateX(-50%);
  width: 32px; height: 3px; border-radius: 0 0 4px 4px;
  background: var(--primary);
}
@media (max-width: 768px) {
  .mobile-bottom-nav { display: block; }
  body { padding-bottom: 56px; }
}

/* ── 20. 移动端筛选抽屉 ──────────────────────────────────── */
.filter-drawer-overlay {
  display: none; position: fixed; inset: 0;
  background: rgba(0,0,0,0.4); z-index: 1200;
  backdrop-filter: blur(2px);
}
.filter-drawer-overlay.open { display: block; }
.filter-drawer {
  position: fixed; bottom: 0; left: 0; right: 0;
  max-height: 80vh; background: #fff;
  border-radius: 20px 20px 0 0;
  padding: 0 20px 24px;
  z-index: 1201;
  transform: translateY(100%);
  transition: transform 0.3s ease;
  overflow-y: auto;
}
.filter-drawer.open { transform: translateY(0); }
.filter-drawer-handle {
  text-align: center; padding: 12px 0 8px;
}
.filter-drawer-handle::before {
  content: "";
  display: inline-block; width: 40px; height: 4px;
  border-radius: 99px; background: #e5e7eb;
}
.filter-drawer-title {
  font-size: 1rem; font-weight: 700;
  color: var(--text); margin: 0 0 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid rgba(108,63,197,0.08);
}
.filter-drawer-footer {
  display: flex; gap: 10px; margin-top: 20px;
}
.filter-drawer-footer .btn { flex: 1; }

/* ── 21. 移动端筛选条（列表页顶部横向滑动） ──────────────── */
.mobile-filter-bar {
  display: none;
  padding: 10px 0 6px;
  overflow-x: auto;
  gap: 8px;
  scrollbar-width: none;
  align-items: center;
}
.mobile-filter-bar::-webkit-scrollbar { display: none; }
.mobile-filter-bar .filter-chip { white-space: nowrap; flex-shrink: 0; }

/* ── 22. 响应式断点 ──────────────────────────────────────── */
@media (max-width: 1024px) {
  .two-col { grid-template-columns: 220px 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 28px; }
}

@media (max-width: 768px) {
  /* Header */
  .header-nav   { display: none; }
  .header-toggle { display: flex; }
  .header-search { max-width: 160px; }
  .header-search input { font-size: 0.82rem; padding: 7px 12px 7px 36px; }

  /* Layout */
  .two-col { grid-template-columns: 1fr; }
  .sidebar  { display: none; }          /* 左侧边栏（筛选） */
  .sidebar-right { display: none; }     /* 右侧边栏（推荐/进度） */
  .home-aside  { display: none; }       /* 首页右侧边栏 */
  .quiz-grid { grid-template-columns: 1fr; }
  .page-wrap { padding: 16px 0 40px; }

  /* Hero */
  .hero { padding: 36px 16px 52px; }
  .hero h1 { font-size: 1.55rem; }
  .hero p  { font-size: 0.9rem; margin-bottom: 20px; }
  .hero-search { border-radius: 12px; padding: 5px 5px 5px 16px; }
  .hero-stats { gap: 20px; margin-top: 28px; }
  .hero-stat .num { font-size: 1.4rem; }

  /* 科目 */
  .subject-grid { grid-template-columns: repeat(4, 1fr); gap: 10px; }
  .subject-card { padding: 14px 8px; gap: 6px; }
  .subject-icon { width: 40px; height: 40px; font-size: 1.25rem; border-radius: 12px; }
  .subject-name { font-size: 0.8rem; }
  .subject-count { display: none; }

  /* 题目卡片 */
  .quiz-card { padding: 14px 16px; }
  .quiz-card-title { font-size: 0.9rem; }

  /* 列表页 mobile filter bar */
  .mobile-filter-bar { display: flex; }

  /* 详情页 question card */
  .question-card { padding: 16px 14px; }
  .option-item { padding: 9px 12px; font-size: 0.88rem; }

  /* 详情页 Action Bar 在移动端更紧凑 */
  .detail-action-bar { padding: 8px 0; }
  .action-bar-inner { gap: 10px; flex-wrap: nowrap; }
  .progress-mini .progress-bar-wrap { width: 80px; }
  .action-bar-inner .btn-ghost { display: none; } /* 收藏/分享按钮在底部导航里 */

  /* Footer 精简 */
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 20px; }
  .footer-col:first-child { grid-column: 1 / -1; } /* 品牌介绍占满一行 */
  .footer-divider { flex-direction: column; gap: 8px; text-align: center; }
  .site-footer { padding: 32px 0 16px; margin-top: 32px; }

  /* 面包屑精简 */
  .breadcrumb li:not(:last-child):not(:nth-last-child(2)) { display: none; }
  .breadcrumb li:nth-last-child(2)::before { display: none; }
}

@media (max-width: 480px) {
  .container { padding: 0 12px; }
  .subject-grid { grid-template-columns: repeat(3, 1fr); }
  .hero h1 { font-size: 1.35rem; }
  .hero-stats { gap: 16px; }
  .hero-stat .num { font-size: 1.2rem; }
  .footer-grid { grid-template-columns: 1fr; }
  .quiz-card-meta { flex-wrap: wrap; gap: 8px; }
  .detail-action-bar .progress-mini { display: none; } /* 超窄屏只保留按钮 */
}