/* ============================================================
   cncuo.com CN错题网 - 全局样式
   全宽自适应 · 响应式 · 方案A 绿色教育风
   ============================================================ */

:root {
  --primary: #16a34a;
  --primary-dark: #15803d;
  --primary-light: #dcfce7;
  --accent: #f59e0b;
  --ink: #0f172a;
  --gray: #64748b;
  --gray-light: #94a3b8;
  --bg: #f8fafc;
  --card: #ffffff;
  --line: #e2e8f0;
  --red: #dc2626;
  --red-light: #fee2e2;
  --radius: 14px;
  --shadow: 0 4px 20px rgba(15, 23, 42, .06);
  --shadow-lg: 0 12px 40px rgba(22, 163, 74, .12);
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { font-size: 16px; }
body {
  font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", system-ui, sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.7;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}
a { text-decoration: none; color: inherit; }
img { max-width: 100%; }
main.main { flex: 1; width: 100%; }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-block; padding: 10px 22px; border-radius: 10px;
  font-weight: 600; font-size: 15px; cursor: pointer; border: none;
  transition: all .18s; text-align: center; line-height: 1.4;
}
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-dark); transform: translateY(-1px); }
.btn-primary:disabled { background: var(--gray-light); cursor: not-allowed; transform: none; }
.btn-outline { background: transparent; border: 1.5px solid var(--primary); color: var(--primary-dark); }
.btn-outline:hover { background: var(--primary-light); }
.btn-ghost { background: transparent; border: 1.5px solid var(--line); color: var(--ink); }
.btn-ghost:hover { border-color: var(--gray-light); }
.btn-white { background: #fff; color: var(--primary-dark); }
.btn-sm { padding: 6px 14px; font-size: 13px; border-radius: 8px; }
.btn-lg { padding: 14px 32px; font-size: 17px; border-radius: 12px; }
.btn-block { width: 100%; }

/* ---------- 导航（全宽） ---------- */
.nav {
  background: rgba(255, 255, 255, .92); backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
  position: sticky; top: 0; z-index: 100; width: 100%;
}
.nav-inner {
  display: flex; align-items: center; gap: 24px;
  padding: 12px 4vw; width: 100%;
}
.logo { display: flex; align-items: center; gap: 10px; font-weight: 800; font-size: 19px; flex-shrink: 0; }
.logo-mark {
  width: 36px; height: 36px; border-radius: 10px; background: var(--primary);
  color: #fff; display: flex; align-items: center; justify-content: center; font-size: 20px; font-weight: 900;
}
.logo-text { display: flex; flex-direction: column; line-height: 1.2; }
.logo-text small { font-size: 11px; color: var(--gray-light); font-weight: 400; }
.nav-links { display: flex; gap: 4px; flex: 1; }
.nav-links a { padding: 8px 14px; border-radius: 8px; color: var(--gray); font-size: 15px; }
.nav-links a:hover { color: var(--primary); background: var(--primary-light); }
.nav-user { display: flex; gap: 8px; align-items: center; flex-shrink: 0; }
.nav-toggle { display: none; background: none; border: none; font-size: 24px; cursor: pointer; color: var(--ink); }
.badge-vip {
  background: linear-gradient(90deg, #fbbf24, #f59e0b); color: #7c2d12;
  padding: 4px 12px; border-radius: 999px; font-size: 12px; font-weight: 700;
}
.badge-free {
  background: var(--primary-light); color: var(--primary-dark);
  padding: 4px 12px; border-radius: 999px; font-size: 12px; font-weight: 600;
}

/* ---------- Hero（全宽） ---------- */
.hero {
  width: 100%;
  background: linear-gradient(135deg, #f0fdf4 0%, #dcfce7 50%, #f0fdf4 100%);
  border-bottom: 1px solid var(--line);
}
.hero-inner {
  display: grid; grid-template-columns: 1.15fr 1fr; gap: 48px;
  padding: 72px 4vw 56px; align-items: center; max-width: 1500px; margin: 0 auto;
}
.hero-tag {
  display: inline-block; background: #fff; color: var(--primary-dark);
  padding: 6px 14px; border-radius: 999px; font-size: 13px; font-weight: 600;
  margin-bottom: 18px; box-shadow: var(--shadow);
}
.hero h1 { font-size: clamp(30px, 4.2vw, 48px); line-height: 1.25; margin-bottom: 16px; }
.hero h1 em { font-style: normal; color: var(--primary); }
.hero-sub { color: var(--gray); font-size: 16px; margin-bottom: 26px; max-width: 620px; }
.hero-sub b { color: var(--primary); font-size: 19px; }
.hero-cta { display: flex; gap: 14px; flex-wrap: wrap; }
.hero-stats { display: flex; gap: 36px; margin-top: 36px; flex-wrap: wrap; }
.hero-stats b { font-size: 26px; color: var(--primary); display: block; }
.hero-stats span { color: var(--gray); font-size: 13px; }

.hero-card {
  background: var(--card); border-radius: 20px; padding: 22px;
  box-shadow: var(--shadow-lg); border: 1px solid var(--line);
}
.hero-card-title { font-weight: 700; margin-bottom: 12px; font-size: 16px; }
.mini-q {
  display: block; padding: 12px 14px; border-radius: 12px; background: var(--bg);
  margin-bottom: 10px; transition: .15s;
}
.mini-q:hover { background: var(--primary-light); }
.mini-q-tag { display: block; font-size: 12px; color: var(--primary-dark); font-weight: 600; }
.mini-q-stem { display: block; font-size: 14px; margin: 4px 0; }
.mini-q-meta { font-size: 12px; color: var(--gray-light); }
.hero-card-more { display: block; text-align: center; color: var(--primary); font-weight: 600; font-size: 14px; padding: 8px; }

/* ---------- 区块（全宽） ---------- */
.section { width: 100%; padding: 64px 4vw; max-width: 1500px; margin: 0 auto; }
.section-gray { background: var(--card); max-width: none; }
.section-gray > * { max-width: 1500px; margin-left: auto; margin-right: auto; }
.section-title { text-align: center; font-size: clamp(24px, 3vw, 32px); margin-bottom: 8px; }
.section-sub { text-align: center; color: var(--gray); margin-bottom: 40px; }

.subject-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 16px;
}
.subject-card {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 26px 16px; text-align: center; transition: .18s; box-shadow: var(--shadow);
}
.subject-card:hover { transform: translateY(-4px); border-color: var(--primary); box-shadow: var(--shadow-lg); }
.subject-icon { font-size: 36px; display: block; margin-bottom: 10px; }
.subject-name { font-weight: 700; font-size: 17px; display: block; }
.subject-count { color: var(--gray); font-size: 13px; }

.feature-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 20px; }
.feature-card {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 28px 24px;
}
.feature-icon {
  width: 52px; height: 52px; border-radius: 14px; background: var(--primary-light);
  display: flex; align-items: center; justify-content: center; font-size: 26px; margin-bottom: 14px;
}
.feature-card h3 { font-size: 17px; margin-bottom: 8px; }
.feature-card p { color: var(--gray); font-size: 14px; }

/* ---------- CTA band（全宽） ---------- */
.band { width: 100%; padding: 0 4vw 64px; }
.band-inner {
  max-width: 1500px; margin: 0 auto;
  background: linear-gradient(120deg, #14532d, #16a34a);
  border-radius: 24px; color: #fff; padding: 44px;
  display: flex; justify-content: space-between; align-items: center; gap: 30px; flex-wrap: wrap;
}
.band-inner h2 { font-size: 26px; margin-bottom: 8px; }
.band-inner p { opacity: .88; }

/* ---------- 页头 ---------- */
.page-head { width: 100%; max-width: 1500px; margin: 0 auto; padding: 40px 4vw 20px; }
.page-head h1 { font-size: clamp(24px, 3vw, 32px); margin-bottom: 6px; }
.page-head p { color: var(--gray); }

/* ---------- 面包屑 ---------- */
.breadcrumb {
  width: 100%; max-width: 1500px; margin: 0 auto; padding: 18px 4vw 0;
  font-size: 13.5px; color: var(--gray-light);
}
.breadcrumb a { color: var(--gray); }
.breadcrumb a:hover { color: var(--primary); }
.breadcrumb .sep { margin: 0 8px; color: var(--line); }

/* ---------- 卡片 ---------- */
.card {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 26px; box-shadow: var(--shadow); margin-bottom: 20px;
}
.card-title { font-size: 17px; margin-bottom: 14px; }

/* ---------- 筛选器 ---------- */
.filter-bar {
  width: 100%; max-width: 1500px; margin: 0 auto 20px; padding: 0 4vw;
}
.filter-row {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 16px 20px; box-shadow: var(--shadow);
}
.filter-group { display: flex; align-items: flex-start; gap: 10px; padding: 7px 0; border-bottom: 1px dashed var(--line); flex-wrap: wrap; }
.filter-group:last-child { border-bottom: none; }
.filter-label { flex-shrink: 0; color: var(--gray); font-size: 14px; font-weight: 600; padding: 4px 0; min-width: 42px; }
.filter-opts { display: flex; flex-wrap: wrap; gap: 6px; flex: 1; }
.filter-opts a {
  padding: 3px 12px; border-radius: 999px; font-size: 13px; color: var(--gray);
}
.filter-opts a:hover { color: var(--primary); background: var(--primary-light); }
.filter-opts a.on { background: var(--primary); color: #fff; font-weight: 600; }
.filter-opts a i { font-style: normal; opacity: .7; font-size: 11px; margin-left: 2px; }
.filter-search { display: flex; gap: 10px; align-items: center; }
.filter-search input {
  flex: 1; padding: 9px 14px; border: 1.5px solid var(--line); border-radius: 10px; font-size: 14px;
}
.filter-search input:focus { outline: none; border-color: var(--primary); }

/* ---------- 题目列表 ---------- */
.q-list { width: 100%; max-width: 1500px; margin: 0 auto; padding: 0 4vw 40px; }
.q-item {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 20px 24px; margin-bottom: 14px; box-shadow: var(--shadow); transition: .15s;
}
.q-item:hover { border-color: var(--primary); }
.q-item.correct { border-left: 4px solid var(--primary); }
.q-item.wrong { border-left: 4px solid var(--red); }
.q-item-head { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; margin-bottom: 10px; }
.q-item-head .right { margin-left: auto; }
.tag {
  display: inline-block; padding: 2px 10px; border-radius: 999px; font-size: 12px;
  background: var(--bg); color: var(--gray); border: 1px solid var(--line);
}
.tag-subject { background: var(--primary-light); color: var(--primary-dark); border-color: transparent; font-weight: 700; }
.tag-ok { background: var(--primary-light); color: var(--primary-dark); border-color: transparent; }
.tag-bad { background: var(--red-light); color: var(--red); border-color: transparent; }
.diff { font-size: 12px; letter-spacing: 1px; }
.diff-1, .diff-2 { color: var(--primary); }
.diff-3 { color: var(--accent); }
.diff-4, .diff-5 { color: var(--red); }
.q-item-stem, .q-stem { font-size: 15.5px; line-height: 1.9; }
.q-item-opts { display: flex; flex-wrap: wrap; gap: 8px 22px; margin-top: 10px; }
.q-opt { font-size: 14px; color: var(--gray); }
.q-item-foot { display: flex; justify-content: space-between; align-items: center; margin-top: 14px; gap: 10px; flex-wrap: wrap; }
.q-note { font-size: 13px; margin-top: 8px; padding: 8px 12px; background: var(--bg); border-radius: 8px; }
.muted { color: var(--gray-light); font-size: 13px; }
.mastery-0 { background: var(--red-light); color: var(--red); border-color: transparent; }
.mastery-1 { background: #fef3c7; color: #92400e; border-color: transparent; }
.mastery-2 { background: #dbeafe; color: #1e40af; border-color: transparent; }
.mastery-3 { background: var(--primary-light); color: var(--primary-dark); border-color: transparent; }
.wrong-actions { display: flex; gap: 8px; align-items: center; }
.mastery-select { padding: 6px 10px; border: 1.5px solid var(--line); border-radius: 8px; font-size: 13px; }

/* ---------- 分页 ---------- */
.pagination { display: flex; justify-content: center; gap: 6px; padding: 10px 4vw 50px; flex-wrap: wrap; }
.pagination a {
  padding: 8px 14px; border-radius: 8px; background: var(--card); border: 1px solid var(--line); font-size: 14px;
}
.pagination a:hover { border-color: var(--primary); color: var(--primary); }
.pagination a.on { background: var(--primary); color: #fff; border-color: var(--primary); }

/* ---------- 题目详情 ---------- */
.q-show { width: 100%; max-width: 1100px; margin: 0 auto; padding: 30px 4vw 60px; }
.q-card, .answer-card, .method-card, .related-card, .lock-card {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 26px 30px; margin-bottom: 18px; box-shadow: var(--shadow);
}
.q-opts { margin-top: 14px; display: grid; gap: 8px; }
.q-opt-row {
  padding: 10px 14px; background: var(--bg); border-radius: 10px; font-size: 15px; display: block;
}
.q-opt-row.clickable { cursor: pointer; display: flex; gap: 10px; align-items: flex-start; }
.q-opt-row.clickable:hover { background: var(--primary-light); }
.q-meta { margin-top: 14px; }
.q-actions { display: flex; gap: 10px; margin-top: 16px; flex-wrap: wrap; }
.block-title { font-size: 18px; margin-bottom: 14px; }
.answer-text { font-size: 17px; font-weight: 700; color: var(--primary-dark); background: var(--primary-light); padding: 14px 18px; border-radius: 10px; }
.analysis-text { color: var(--ink); }
.method-card { border-left: 4px solid var(--primary); }
.method-title { display: flex; align-items: center; gap: 10px; }
.method-no {
  width: 30px; height: 30px; border-radius: 50%; background: var(--primary); color: #fff;
  display: inline-flex; align-items: center; justify-content: center; font-size: 15px; font-weight: 700; flex-shrink: 0;
}
.method-steps { line-height: 2; }
.method-answer {
  margin-top: 14px; padding: 12px 16px; background: var(--primary-light);
  border-radius: 10px; color: var(--primary-dark); font-weight: 700;
}
.lock-card { text-align: center; padding: 50px 30px; }
.lock-icon { font-size: 46px; margin-bottom: 14px; }
.lock-card h3 { font-size: 20px; margin-bottom: 8px; }
.lock-card p { color: var(--gray); margin-bottom: 20px; }
.related-list { display: grid; gap: 8px; }
.related-item {
  display: block; padding: 12px 16px; background: var(--bg); border-radius: 10px;
  font-size: 14px; transition: .15s;
}
.related-item:hover { background: var(--primary-light); }
.ai-box {
  margin-top: 16px; padding: 18px; background: #f0f9ff; border: 1px solid #bae6fd;
  border-radius: 12px; font-size: 14.5px; line-height: 1.9; white-space: pre-wrap;
}
.ai-box.loading { color: var(--gray); }

/* ---------- 表单 ---------- */
.form-group { margin-bottom: 16px; }
.form-group label { display: block; font-size: 14px; font-weight: 600; margin-bottom: 6px; }
.form-group input, .form-group select, .form-group textarea, select, textarea {
  width: 100%; padding: 10px 14px; border: 1.5px solid var(--line); border-radius: 10px;
  font-size: 15px; font-family: inherit; background: #fff;
}
.form-group input:focus, .form-group select:focus, textarea:focus { outline: none; border-color: var(--primary); }
.checkbox { display: flex; align-items: center; gap: 8px; font-size: 14px; color: var(--gray); margin-bottom: 16px; }
.checkbox input { width: auto; }
.form-row { display: grid; grid-template-columns: repeat(auto-fit, minmax(160px, 1fr)); gap: 14px; }

.alert { padding: 12px 18px; border-radius: 10px; margin-bottom: 18px; font-size: 14.5px; max-width: 1500px; margin-left: 4vw; margin-right: 4vw; }
.alert-error { background: var(--red-light); color: var(--red); }
.alert-success { background: var(--primary-light); color: var(--primary-dark); }

/* ---------- 登录注册 ---------- */
.auth-page { display: flex; justify-content: center; padding: 60px 4vw; }
.auth-card {
  width: 100%; max-width: 420px; background: var(--card); border: 1px solid var(--line);
  border-radius: 18px; padding: 36px; box-shadow: var(--shadow-lg);
}
.auth-card h2 { margin-bottom: 22px; text-align: center; }
.auth-switch { text-align: center; margin-top: 18px; color: var(--gray); font-size: 14px; }
.auth-switch a { color: var(--primary); font-weight: 600; }

/* ---------- AI 页 ---------- */
.ai-page {
  display: grid; grid-template-columns: 1.4fr 1fr; gap: 20px;
  width: 100%; max-width: 1500px; margin: 0 auto; padding: 0 4vw 50px;
}
.quota-bar {
  padding: 10px 16px; background: var(--primary-light); border-radius: 10px;
  color: var(--primary-dark); font-size: 14px; margin-bottom: 16px;
  display: flex; align-items: center; gap: 10px; flex-wrap: wrap;
}
.ai-actions { display: flex; align-items: center; gap: 14px; margin-top: 14px; }
.ai-result {
  margin-top: 20px; padding: 22px; background: var(--bg); border-radius: 12px;
  white-space: pre-wrap; line-height: 1.9; font-size: 15px; border: 1px solid var(--line);
}
.ai-result.loading { color: var(--gray); }
.ai-history { display: grid; gap: 8px; max-height: 560px; overflow-y: auto; }
.ai-history-item summary {
  cursor: pointer; padding: 10px 12px; background: var(--bg); border-radius: 10px; font-size: 13.5px;
}
.ai-history-item summary:hover { background: var(--primary-light); }
.ai-history-body { padding: 12px; font-size: 13px; color: var(--gray); white-space: pre-wrap; }

/* ---------- 练习 ---------- */
.practice-page { width: 100%; max-width: 1100px; margin: 0 auto; padding: 0 4vw 50px; }
.practice-history { display: grid; gap: 8px; }
.practice-history-item {
  display: flex; justify-content: space-between; align-items: center; gap: 10px;
  padding: 12px 16px; background: var(--bg); border-radius: 10px; font-size: 14px; flex-wrap: wrap;
}
.practice-history-item:hover { background: var(--primary-light); }
.rate { font-weight: 800; font-size: 16px; }
.rate.good, .good-text { color: var(--primary); }
.rate.mid, .mid-text { color: var(--accent); }
.rate.bad, .bad-text { color: var(--red); }
.paper { width: 100%; max-width: 1100px; margin: 0 auto; padding: 0 4vw 50px; }
.paper-item {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 24px 28px; margin-bottom: 16px; box-shadow: var(--shadow);
}
.paper-item-head { display: flex; align-items: center; gap: 8px; margin-bottom: 12px; flex-wrap: wrap; }
.paper-no {
  width: 28px; height: 28px; border-radius: 8px; background: var(--primary); color: #fff;
  display: inline-flex; align-items: center; justify-content: center; font-weight: 700; font-size: 14px;
}
.paper-item .q-stem { margin-bottom: 14px; }
.paper-submit { text-align: center; padding: 20px 0 10px; display: flex; flex-direction: column; gap: 8px; align-items: center; }
.result-summary {
  display: flex; align-items: center; gap: 30px; max-width: 1100px; margin: 0 auto 20px;
  margin-left: auto; margin-right: auto; flex-wrap: wrap;
}
.result-ring {
  width: 110px; height: 110px; border-radius: 50%; background: var(--primary-light);
  display: flex; align-items: center; justify-content: center; font-size: 34px; font-weight: 800;
  color: var(--primary-dark); flex-shrink: 0;
}
.result-ring i { font-size: 16px; font-style: normal; margin-left: 2px; }

/* ---------- 套餐 ---------- */
.plan-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 20px;
  width: 100%; max-width: 1500px; margin: 0 auto; padding: 0 4vw 30px;
}
.plan-card {
  background: var(--card); border: 2px solid var(--line); border-radius: 20px;
  padding: 30px 26px; position: relative; transition: .18s;
}
.plan-card.featured { border-color: var(--primary); box-shadow: var(--shadow-lg); }
.plan-tag {
  position: absolute; top: -13px; left: 50%; transform: translateX(-50%);
  background: var(--primary); color: #fff; padding: 3px 18px; border-radius: 999px;
  font-size: 13px; font-weight: 700;
}
.plan-card h3 { text-align: center; font-size: 19px; }
.plan-price { text-align: center; margin: 16px 0 4px; }
.plan-price small { font-size: 18px; color: var(--primary); }
.plan-price { font-size: 42px; font-weight: 800; color: var(--primary); }
.plan-price span { font-size: 14px; color: var(--gray); font-weight: 400; }
.plan-perday { text-align: center; color: var(--gray-light); font-size: 13px; margin-bottom: 18px; }
.plan-features { list-style: none; margin-bottom: 22px; }
.plan-features li { padding: 6px 0 6px 26px; position: relative; font-size: 14.5px; color: var(--gray); }
.plan-features li::before { content: "✓"; position: absolute; left: 0; color: var(--primary); font-weight: 800; }
.pay-channels { display: grid; gap: 8px; margin-bottom: 14px; }
.pay-channel {
  display: flex; align-items: center; gap: 8px; padding: 10px 14px;
  border: 1.5px solid var(--line); border-radius: 10px; cursor: pointer; font-size: 14px;
}
.pay-channel:has(input:checked) { border-color: var(--primary); background: var(--primary-light); }
.pay-channel input { width: auto; }
.plan-compare { max-width: 1500px; margin: 0 auto 50px; margin-left: 4vw; margin-right: 4vw; }

/* ---------- 支付 ---------- */
.pay-page { display: flex; justify-content: center; padding: 50px 4vw; }
.pay-card { width: 100%; max-width: 480px; text-align: center; }
.pay-card .table { text-align: left; margin: 18px 0; }
.price-text { color: var(--primary); font-weight: 800; font-size: 19px; }
.qr-box { padding: 20px; }

/* ---------- 个人中心 / 后台 ---------- */
.dash-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); gap: 20px;
  width: 100%; max-width: 1500px; margin: 0 auto; padding: 0 4vw;
}
.dash-grid + .card, .dash-grid + * .card { margin-left: 4vw; margin-right: 4vw; }
.dash-quota { grid-column: 1 / -1; }
.quota-rows { display: grid; gap: 14px; }
.quota-row { display: grid; grid-template-columns: 90px 1fr 90px; align-items: center; gap: 14px; font-size: 14px; }
.quota-progress { height: 10px; background: var(--bg); border-radius: 999px; overflow: hidden; }
.quota-progress i { display: block; height: 100%; background: var(--primary); border-radius: 999px; transition: width .3s; }
.dash-stats { display: flex; gap: 28px; flex-wrap: wrap; margin-bottom: 16px; }
.dash-stats b { font-size: 24px; color: var(--primary); display: block; }
.dash-stats span { color: var(--gray); font-size: 13px; }
.dash-links { display: flex; gap: 10px; flex-wrap: wrap; }
.admin-stats {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 16px;
  width: 100%; max-width: 1500px; margin: 0 auto 20px; padding: 0 4vw;
}
.stat-card {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 22px; text-align: center; box-shadow: var(--shadow);
}
.stat-card b { font-size: 24px; color: var(--primary); display: block; }
.stat-card span { color: var(--gray); font-size: 13px; }
.dash-grid ~ .card, body .q-list ~ .card { max-width: 1500px; margin-left: auto; margin-right: auto; width: calc(100% - 8vw); }
main.main > .card { max-width: 1500px; margin-left: auto; margin-right: auto; width: calc(100% - 8vw); }

/* ---------- 表格 ---------- */
.table { width: 100%; border-collapse: collapse; font-size: 14px; }
.table th, .table td { padding: 10px 12px; border-bottom: 1px solid var(--line); text-align: left; }
.table th { color: var(--gray); font-weight: 600; background: var(--bg); }
.table tr:hover td { background: #fbfefc; }
.mono { font-family: Consolas, monospace; font-size: 12.5px; }

/* ---------- 空状态 / 错误页 ---------- */
.empty { text-align: center; padding: 60px 20px; color: var(--gray); }
.empty a { color: var(--primary); }
.error-page { text-align: center; padding: 100px 4vw; }
.error-code { font-size: 90px; font-weight: 900; color: var(--primary-light); -webkit-text-stroke: 2px var(--primary); }
.error-page p { color: var(--gray); margin: 14px 0 26px; }

/* ---------- 页脚（全宽） ---------- */
.footer { width: 100%; background: var(--card); border-top: 1px solid var(--line); margin-top: auto; }
.footer-inner {
  display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 30px;
  padding: 44px 4vw; max-width: 1500px; margin: 0 auto;
}
.footer-col h4 { margin-bottom: 12px; font-size: 15px; }
.footer-col a { display: block; color: var(--gray); font-size: 14px; padding: 3px 0; }
.footer-col a:hover { color: var(--primary); }
.footer-col p { color: var(--gray); font-size: 14px; padding: 3px 0; }
.footer-bottom {
  text-align: center; padding: 16px; color: var(--gray-light); font-size: 13px;
  border-top: 1px solid var(--line);
}
.footer-bottom a { color: var(--gray); }
.footer-bottom a:hover { color: var(--primary); }

/* ---------- 版权声明页（/copyright 专用页面） ---------- */
.copyright-page { max-width: 900px; }
.copyright-page .card { padding: 30px 34px; }
.copyright-page h2 { font-size: 19px; margin: 22px 0 10px; }
.copyright-page h2:first-of-type { margin-top: 4px; }
.copyright-page p { color: var(--gray); font-size: 15px; line-height: 1.9; margin-bottom: 10px; }
.copyright-page .copyright-contact {
  display: inline-block; margin-top: 8px; padding: 10px 16px;
  background: var(--primary-light); color: var(--primary-dark);
  border-radius: 10px; font-weight: 600; font-size: 14px;
}
@media (max-width: 640px) {
  .copyright-page .card { padding: 22px 18px; }
}

/* ---------- 版权与题目来源声明（首页醒目区块） ---------- */
.copyright-band { padding-top: 40px; padding-bottom: 40px; }
.copyright-inner {
  max-width: 1500px; margin: 0 auto; background: var(--card);
  border: 1px solid var(--line); border-left: 5px solid var(--primary);
  border-radius: var(--radius); box-shadow: var(--shadow);
  padding: 26px 30px;
}
.copyright-head { display: flex; align-items: center; gap: 12px; margin-bottom: 14px; }
.copyright-icon {
  flex: 0 0 auto; width: 34px; height: 34px; border-radius: 50%;
  background: var(--primary-light); color: var(--primary-dark);
  display: inline-flex; align-items: center; justify-content: center;
  font-size: 18px; font-weight: 700;
}
.copyright-title { font-size: 20px; font-weight: 700; }
.copyright-body p { color: var(--gray); font-size: 14.5px; line-height: 1.9; margin-bottom: 8px; }
.copyright-body p:last-child { margin-bottom: 0; }
.copyright-foot {
  margin-top: 16px; padding-top: 14px; border-top: 1px dashed var(--line);
  color: var(--gray-light); font-size: 13px;
}
.copyright-contact { color: var(--primary-dark); font-weight: 600; }
@media (max-width: 640px) {
  .copyright-band { padding-left: 4vw; padding-right: 4vw; }
  .copyright-inner { padding: 20px 18px; }
  .copyright-title { font-size: 17px; }
}

/* ---------- 响应式 ---------- */
@media (max-width: 1024px) {
  .hero-inner { grid-template-columns: 1fr; gap: 30px; }
  .ai-page { grid-template-columns: 1fr; }
  .footer-inner { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 768px) {
  .nav-inner { flex-wrap: wrap; gap: 10px; }
  .nav-toggle { display: block; margin-left: auto; }
  .nav-links { display: none; width: 100%; flex-direction: column; order: 3; }
  .nav-links.open { display: flex; }
  .nav-user { width: 100%; justify-content: flex-end; order: 2; }
  .hero-inner { padding: 44px 4vw 36px; }
  .hero-stats { gap: 20px; }
  .band-inner { padding: 30px; flex-direction: column; text-align: center; }
  .q-card, .answer-card, .method-card, .related-card, .lock-card { padding: 20px; }
  .quota-row { grid-template-columns: 70px 1fr 70px; }
  .footer-inner { grid-template-columns: 1fr; gap: 20px; padding: 30px 4vw; }
  .q-item-foot { flex-direction: column; align-items: flex-start; }
  .result-summary { justify-content: center; text-align: center; }
}

/* ---------- 后台选项卡 ---------- */
.admin-tabs { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 22px; }
.admin-tab {
  padding: 8px 18px; border-radius: 999px; background: #fff; border: 1px solid var(--line);
  color: var(--gray); font-size: 14px; font-weight: 500;
}
.admin-tab:hover { border-color: var(--primary); color: var(--primary); }
.admin-tab.active { background: var(--primary); border-color: var(--primary); color: #fff; }

/* ---------- 后台配置页 ---------- */
.settings-group { margin-bottom: 20px; }
.settings-field { margin-bottom: 16px; }
.settings-key {
  font-size: 12px; color: var(--gray-light); background: var(--bg);
  padding: 2px 6px; border-radius: 4px; font-weight: 400;
}
.form-hint { font-size: 12px; color: var(--gray-light); margin-top: 4px; }
.switch-row { display: flex; align-items: center; gap: 8px; font-size: 14px; color: var(--ink); cursor: pointer; }
.switch-row input { width: 18px; height: 18px; accent-color: var(--primary); }
.settings-submit { position: sticky; bottom: 16px; text-align: center; }
.settings-submit .btn { box-shadow: 0 6px 20px rgba(22,163,74,.35); }
.admin-filter { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; margin-bottom: 16px; }
.admin-filter input[type="text"], .admin-filter select { padding: 8px 12px; border: 1px solid var(--line); border-radius: 8px; font-size: 14px; }
.inline-form { display: inline; }
.table-ops { white-space: nowrap; }
.table-ops .btn { margin: 1px 2px; }
.btn.danger, .btn-ghost.danger { color: #dc2626; }
.q-stem-cell { max-width: 320px; font-size: 13px; color: var(--gray); }
.user-edit { position: relative; }
.user-edit summary { list-style: none; cursor: pointer; }
.user-edit summary::-webkit-details-marker { display: none; }
.user-edit-form {
  position: absolute; right: 0; z-index: 20; background: #fff; border: 1px solid var(--line);
  border-radius: 10px; padding: 14px; display: flex; flex-direction: column; gap: 10px; width: 240px;
  box-shadow: 0 8px 30px rgba(0,0,0,.12);
}
.user-edit-form input[type="password"] { padding: 8px 10px; border: 1px solid var(--line); border-radius: 8px; }
.pager { display: flex; gap: 6px; margin-top: 16px; flex-wrap: wrap; }
.pager-item { padding: 6px 12px; border: 1px solid var(--line); border-radius: 8px; font-size: 13px; color: var(--gray); background: #fff; }
.pager-item.active { background: var(--primary); border-color: var(--primary); color: #fff; }

/* ---------- 题型多选 ---------- */
.type-checks { display: flex; flex-wrap: wrap; gap: 8px; }
.type-check {
  display: inline-flex; align-items: center; gap: 6px; padding: 6px 12px;
  border: 1px solid var(--line); border-radius: 999px; font-size: 13px; cursor: pointer; background: #fff;
}
.type-check input { accent-color: var(--primary); }
.type-check:has(input:checked) { border-color: var(--primary); color: var(--primary); background: #f0fdf4; }

/* ---------- 自评改判 ---------- */
.selfmark-bar {
  display: flex; align-items: center; gap: 10px; margin-top: 12px; padding: 12px 16px;
  background: #fffbeb; border: 1px dashed #f59e0b; border-radius: 10px; flex-wrap: wrap;
}
.q-item.pending { border-left-color: #f59e0b; }
.tag-mid { background: #fffbeb; color: #b45309; }
.rate.mid, .mid { color: #d97706; }

/* ---------- 模拟卷 ---------- */
.paper-list { width: 100%; max-width: 1500px; margin: 0 auto; padding: 0 4vw 40px; }
.paper-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 18px; }
.paper-card {
  background: #fff; border: 1px solid var(--line); border-radius: 14px; padding: 20px;
  display: flex; flex-direction: column; gap: 10px; transition: all .2s;
}
.paper-card:hover { border-color: var(--primary); box-shadow: 0 8px 24px rgba(22,163,74,.12); transform: translateY(-2px); }
.paper-card-head { display: flex; align-items: center; gap: 8px; }
.paper-year { margin-left: auto; font-weight: 700; color: var(--primary); }
.paper-card-title {
  font-size: 16px; color: var(--ink); line-height: 1.4;
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden;
  min-height: 2.8em;
}
.paper-card-desc {
  font-size: 13px; color: var(--gray-light); flex: 1;
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden;
}
.paper-card-meta { display: flex; flex-wrap: wrap; gap: 6px 14px; font-size: 13px; color: var(--gray); }
.paper-card-btn { align-self: flex-start; }
.paper-detail { display: grid; grid-template-columns: 1.2fr 1fr; gap: 20px; align-items: start; }
.paper-meta-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin: 14px 0; }
.paper-meta-item { text-align: center; background: var(--bg); border-radius: 10px; padding: 14px 8px; }
.paper-meta-item b { display: block; font-size: 24px; color: var(--primary); }
.paper-meta-item span { font-size: 12px; color: var(--gray-light); }
.paper-struct-title { margin: 18px 0 10px; font-size: 15px; }
.paper-rules { padding-left: 18px; color: var(--gray); font-size: 14px; line-height: 2; }
.paper-knows { display: flex; flex-wrap: wrap; gap: 8px; }
.paper-timer { position: sticky; top: 70px; z-index: 30; text-align: center; font-size: 15px; margin-bottom: 18px; }
.paper-timer.overtime { border-color: #dc2626; color: #dc2626; }
.judge-opts { display: flex; gap: 16px; }
.judge-opts .q-opt-row { min-width: 120px; }

@media (max-width: 900px) {
  .paper-detail { grid-template-columns: 1fr; }
  .paper-grid { grid-template-columns: 1fr; }
}

/* ==================== v2.1 布局整理 ==================== */
/* 后台页签对齐主内容宽度 */
.admin-tabs {
  width: 100%; max-width: 1500px; margin: 0 auto 24px; padding: 0 4vw;
}
/* 后台配置表单容器 */
.admin-settings {
  width: 100%; max-width: 1500px; margin: 0 auto; padding: 0 4vw 40px;
}
/* 配置项：宽屏左右两栏（标签 | 控件），窄屏单列 */
.settings-field {
  display: grid; grid-template-columns: 280px minmax(0, 1fr);
  gap: 6px 20px; align-items: start; padding: 12px 0;
  border-bottom: 1px dashed var(--line);
}
.settings-field:last-child { border-bottom: none; }
.settings-field > label { margin-bottom: 0; padding-top: 8px; }
.settings-field > input, .settings-field > select, .settings-field > textarea { width: 100%; max-width: 560px; }
.settings-field .form-hint { grid-column: 1 / -1; margin-top: 0; }
.settings-field .switch-row { padding-top: 6px; }
/* 宽表格横向滚动，不再撑破卡片 */
.table-scroll { width: 100%; overflow-x: auto; -webkit-overflow-scrolling: touch; }
.table-scroll .table { min-width: 640px; }
.table-scroll .table th, .table-scroll .table td { white-space: nowrap; }
.table-scroll .table td.q-stem-cell { white-space: normal; min-width: 220px; }
/* 表格操作列按钮不换行挤压 */
.table-ops { display: flex; align-items: center; gap: 4px; }
.table-ops form { display: inline; }
/* 后台顶部 / 表单底部操作栏：与表格操作列 .table-ops 区分，间距与全站一致并可换行 */
.admin-toolbar { display: flex; flex-wrap: wrap; align-items: center; gap: 12px; margin: 0 0 16px; }
.admin-toolbar .btn { margin: 0; }
.admin-toolbar .toolbar-hint { font-size: 13px; color: var(--gray-light); margin-left: auto; }
.admin-toolbar.form-actions { margin: 18px 0 0; padding-top: 16px; border-top: 1px solid var(--line); }
@media (max-width: 640px) {
  .admin-toolbar { gap: 8px; }
  .admin-toolbar .toolbar-hint { margin-left: 0; width: 100%; }
}
/* 后台筛选栏对齐 */
.admin-filter input[type="text"] { min-width: 200px; }
/* 统一后台表单容器边距 */
.dash-grid .card { margin-bottom: 20px; }
/* 页码居右 */
.pager { justify-content: flex-end; }
@media (max-width: 900px) {
  .settings-field { grid-template-columns: 1fr; }
  .settings-field > label { padding-top: 0; }
  .settings-submit { position: static; }
  .pager { justify-content: flex-start; }
}

/* ==================== v2.3 全站容器对齐统一 ==================== */
/*
 * 统一规则：所有页面顶层内容容器 → 左右各 4vw 留白、内容最大宽 1500px、水平居中。
 * 从此标题 / 面包屑 / 筛选栏 / 卡片 / 表格 / 网格全部对齐同一条竖线。
 */
.page-head,
.breadcrumb,
.filter-bar,
.q-list,
.paper-list,
.paper-detail,
.ai-page,
.result-summary,
.admin-tabs,
.admin-stats,
/* 后台顶部工具栏（仅限页面顶层；嵌在卡片内的 .form-actions 不受影响） */
main.main > .admin-toolbar,
.admin-settings,
.dash-grid,
.plan-grid,
.plan-compare,
.practice-page,
.paper,
.q-show,
.hero-inner,
.section,
.section-gray > *,
.footer-inner {
  width: calc(100% - 8vw);
  max-width: 1500px;
  margin-left: auto;
  margin-right: auto;
  padding-left: 0;
  padding-right: 0;
}
/* 卡片/提示条自身有内边距，只统一宽度与居中，不覆盖内边距 */
main.main > .card,
.dash-grid ~ .card,
body .q-list ~ .card,
main.main > .alert {
  width: calc(100% - 8vw);
  max-width: 1500px;
  margin-left: auto;
  margin-right: auto;
}
/* CTA 横幅自带 44px 内边距，只统一宽度（父级 .band 已有 4vw 留白） */
.band > .band-inner { max-width: 1500px; margin-left: auto; margin-right: auto; }
/* section-gray 自身保持全宽背景（子元素受限） */
.section.section-gray { width: 100%; max-width: none; }
/* 卡片之间的纵向间距保持不变 */
main.main > .card + .card { margin-top: 20px; }

/* ---------- 首页卡片网格整齐化 ---------- */
/* 学科卡片：10 个学科 → 固定 5 列 × 2 行，不再出现 7+3 断行 */
.subject-grid { grid-template-columns: repeat(5, 1fr); }
/* 首页模拟卷：6 张 → 固定 3 列 × 2 行，不再出现 4+2 断行 */
.section .paper-grid { grid-template-columns: repeat(3, 1fr); }

/* ---------- 面包屑统一样式：位置固定在页面最顶部（标题上方） ---------- */
.breadcrumb {
  font-size: 13px; color: var(--gray);
  display: flex; flex-wrap: wrap; gap: 6px; align-items: center;
  padding-top: 18px; padding-bottom: 0;
}
.breadcrumb a { color: var(--gray); }
.breadcrumb a:hover { color: var(--primary); }
.breadcrumb .crumb-sep, .breadcrumb .sep { color: var(--line); margin: 0 2px; }

/* ---------- 响应式降级 ---------- */
@media (max-width: 1200px) {
  .subject-grid { grid-template-columns: repeat(4, 1fr); }
}
@media (max-width: 900px) {
  .subject-grid { grid-template-columns: repeat(3, 1fr); }
  .section .paper-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 640px) {
  .subject-grid { grid-template-columns: repeat(2, 1fr); }
  .section .paper-grid { grid-template-columns: 1fr; }
}