/* MathGame 官网样式 —— 与 App 同一套配色（深空蓝 + 青蓝渐变） */
:root {
  --bg0: #070b1c;
  --bg1: #0d1633;
  --bg2: #13204d;
  --text: #eef3ff;
  --dim: #8fa0c9;
  --faint: #5d6d96;
  --blue: #4f7cff;
  --cyan: #22d3ee;
  --orange: #ffb020;
  --red: #ff5a6e;
  --green: #34d399;
  --glass: rgba(255, 255, 255, .055);
  --border: rgba(255, 255, 255, .1);
  --grad: linear-gradient(135deg, var(--blue), var(--cyan));
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg0);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Helvetica Neue",
               "Microsoft YaHei", system-ui, sans-serif;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

/* 顶部光晕背景 */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  background:
    radial-gradient(900px 500px at 20% -10%, rgba(79, 124, 255, .18), transparent 60%),
    radial-gradient(700px 400px at 90% 0%, rgba(34, 211, 238, .12), transparent 60%);
  pointer-events: none;
  z-index: 0;
}

.wrap {
  position: relative;
  z-index: 1;
  max-width: 860px;
  margin: 0 auto;
  padding: 0 20px 80px;
}

/* ---------- 顶部导航 ---------- */
.nav {
  position: relative;
  z-index: 2;
  display: flex;
  align-items: center;
  gap: 8px;
  max-width: 860px;
  margin: 0 auto;
  padding: 18px 20px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 9px;
  font-weight: 800;
  font-size: 17px;
  color: var(--text);
  text-decoration: none;
  letter-spacing: .3px;
}

.logo-mark {
  width: 30px;
  height: 30px;
  border-radius: 9px;
  background: var(--grad);
  display: grid;
  place-items: center;
  font-size: 16px;
  box-shadow: 0 6px 18px rgba(79, 124, 255, .35);
}

.nav-links {
  margin-left: auto;
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
}

.nav-links a {
  color: var(--dim);
  text-decoration: none;
  font-size: 13.5px;
  padding: 6px 10px;
  border-radius: 8px;
  transition: .2s;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--text);
  background: var(--glass);
}

/* ---------- Hero ---------- */
.hero { padding: 46px 0 26px; }

.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 12px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--glass);
  color: var(--cyan);
  font-size: 12.5px;
  font-weight: 600;
}

h1 {
  margin: 18px 0 14px;
  font-size: clamp(30px, 6.4vw, 44px);
  line-height: 1.25;
  font-weight: 800;
  letter-spacing: -.5px;
}

h1 .hl {
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.lead {
  color: var(--dim);
  font-size: 16.5px;
  max-width: 620px;
  margin: 0 0 26px;
}

.cta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 12px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 22px;
  border-radius: 12px;
  font-weight: 700;
  font-size: 15px;
  text-decoration: none;
  transition: transform .15s, box-shadow .2s;
}

.btn:hover { transform: translateY(-2px); }

.btn-primary {
  background: var(--grad);
  color: #04122b;
  box-shadow: 0 10px 26px rgba(79, 124, 255, .32);
}

.btn-ghost {
  border: 1px solid var(--border);
  color: var(--text);
  background: var(--glass);
}

.note { color: var(--faint); font-size: 13px; }

/* ---------- 卡片 / 区块 ---------- */
section { margin: 40px 0; }

h2 {
  font-size: 22px;
  margin: 0 0 6px;
  font-weight: 750;
}

h3 {
  font-size: 16px;
  margin: 22px 0 6px;
  color: var(--cyan);
  font-weight: 700;
}

.sub { color: var(--faint); font-size: 14px; margin: 0 0 18px; }

.grid {
  display: grid;
  gap: 14px;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
}

.card {
  padding: 18px;
  border: 1px solid var(--border);
  border-radius: 14px;
  background: linear-gradient(180deg, rgba(255, 255, 255, .045), rgba(255, 255, 255, .015));
}

.card .icon { font-size: 22px; margin-bottom: 8px; display: block; }

.card p { margin: 0; color: var(--dim); font-size: 14.5px; }

.card strong { display: block; margin-bottom: 4px; font-size: 15.5px; }

/* ---------- 层级/特色列表 ---------- */
.tiers { display: grid; gap: 10px; }

.tier {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 14px;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: var(--glass);
}

.chip {
  min-width: 62px;
  text-align: center;
  padding: 5px 10px;
  border-radius: 8px;
  font-size: 12.5px;
  font-weight: 800;
  color: #04122b;
}

.tier span { color: var(--dim); font-size: 14px; }

/* ---------- 正文（政策类页面） ---------- */
.doc h1 { font-size: clamp(26px, 5vw, 34px); }

.doc .meta {
  color: var(--faint);
  font-size: 13.5px;
  border-bottom: 1px solid var(--border);
  padding-bottom: 14px;
  margin-bottom: 26px;
}

.doc p { color: var(--dim); }

.doc ul { color: var(--dim); padding-left: 22px; }

.doc li { margin: 6px 0; }

.doc strong { color: var(--text); }

.doc a { color: var(--cyan); }

.doc h2 {
  font-size: 19px;
  margin-top: 34px;
  padding-top: 22px;
  border-top: 1px solid var(--border);
}

.doc h2:first-of-type { border-top: 0; }

.callout {
  border-left: 3px solid var(--orange);
  background: rgba(255, 176, 32, .07);
  padding: 12px 16px;
  border-radius: 0 10px 10px 0;
  margin: 18px 0;
}

.callout p { margin: 0; color: var(--text); font-size: 14.5px; }

/* 表格 */
table {
  width: 100%;
  border-collapse: collapse;
  margin: 16px 0;
  font-size: 14px;
}

th, td {
  text-align: left;
  padding: 10px 12px;
  border-bottom: 1px solid var(--border);
  color: var(--dim);
}

th { color: var(--text); font-weight: 700; background: var(--glass); }

/* ---------- 页脚 ---------- */
footer {
  border-top: 1px solid var(--border);
  padding-top: 24px;
  margin-top: 56px;
  color: var(--faint);
  font-size: 13px;
}

footer a { color: var(--dim); text-decoration: none; margin-right: 16px; }

footer a:hover { color: var(--cyan); }

/* 小屏适配 */
@media (max-width: 560px) {
  .wrap { padding-bottom: 56px; }
  .hero { padding: 28px 0 18px; }
  .btn { width: 100%; justify-content: center; }
  .nav { flex-wrap: wrap; }
  .nav-links { margin-left: 0; width: 100%; }
}

/* 打印（政策页可被导出） */
@media print {
  body { background: #fff; color: #111; }
  body::before { display: none; }
  .doc p, .doc ul, td { color: #222; }
  .doc h2 { border-top: 1px solid #ddd; }
  .nav, footer .links { display: none; }
}