:root {
  --navy-900: #0f2f4d;
  --navy-800: #143d63;
  --blue-700: #1c5a94;
  --blue-600: #2470c2;
  --blue-500: #2e7dd1;
  --blue-100: #dbe9f8;
  --blue-50: #eef4fb;
  --bg: #f4f7fb;
  --card: #ffffff;
  --ink: #22303f;
  --ink-soft: #5a6b80;
  --line: #dce6f1;
  --amber: #a86a12;
  --amber-bg: #fdf6e7;
  --green: #2b7350;
  --green-bg: #eefaf2;
  --red: #b03a2e;
  --radius: 12px;
  --shadow: 0 1px 2px rgba(15, 47, 77, 0.06), 0 6px 18px rgba(15, 47, 77, 0.06);
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Segoe UI", system-ui, sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.75;
  font-size: 16px;
}

.container { max-width: 1100px; margin: 0 auto; padding: 0 20px; }
a { color: var(--blue-700); }

/* ===== 顶栏 ===== */
.site-header {
  background: var(--navy-900);
  color: #fff;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 1px 0 rgba(255,255,255,0.06), 0 4px 16px rgba(15,47,77,0.18);
}
.site-header .container {
  display: flex; align-items: center; justify-content: space-between;
  flex-wrap: wrap; gap: 8px; min-height: 62px;
}
.brand { display: flex; align-items: center; gap: 11px; text-decoration: none; color: #fff; }
.brand .logo {
  width: 34px; height: 34px; border-radius: 8px;
  background: linear-gradient(135deg, #2e7dd1, #1c5a94);
  display: flex; align-items: center; justify-content: center;
  font-size: 16px; font-weight: 700;
  border: 1px solid rgba(255,255,255,0.22);
}
.brand .brand-text { display: flex; flex-direction: column; line-height: 1.25; }
.brand .brand-name { font-size: 17px; font-weight: 700; letter-spacing: 0.5px; }
.brand .brand-sub { font-size: 11px; color: rgba(255,255,255,0.55); letter-spacing: 0.4px; }
.main-nav { display: flex; gap: 2px; flex-wrap: wrap; }
.main-nav a {
  color: rgba(255,255,255,0.82); text-decoration: none;
  padding: 7px 13px; border-radius: 7px; font-size: 14.5px;
  transition: background 0.18s, color 0.18s;
}
.main-nav a:hover { background: rgba(255,255,255,0.1); color: #fff; }
.main-nav a.active { background: rgba(255,255,255,0.15); color: #fff; font-weight: 600; }

/* ===== 子导航（备考专区） ===== */
.subnav { background: #fff; border-bottom: 1px solid var(--line); }
.subnav .container { display: flex; gap: 6px; flex-wrap: wrap; padding-top: 9px; padding-bottom: 9px; }
.subnav a {
  font-size: 13.5px; text-decoration: none; color: var(--ink-soft);
  padding: 4px 12px; border-radius: 20px; border: 1px solid transparent;
}
.subnav a:hover { color: var(--blue-700); background: var(--blue-50); }
.subnav a.active { color: var(--blue-700); background: var(--blue-50); border-color: var(--blue-100); font-weight: 600; }

/* ===== Hero ===== */
.hero {
  background:
    linear-gradient(rgba(255,255,255,0.035) 1px, transparent 1px) 0 0 / 100% 26px,
    linear-gradient(90deg, rgba(255,255,255,0.035) 1px, transparent 1px) 0 0 / 26px 100%,
    linear-gradient(135deg, #0f2f4d 0%, #143d63 55%, #1c5a94 100%);
  color: #fff;
  padding: 56px 0 46px;
}
.hero .eyebrow {
  display: inline-block; font-size: 12px; letter-spacing: 3px;
  color: rgba(255,255,255,0.6); margin-bottom: 12px;
  border-left: 2px solid var(--blue-500); padding-left: 10px;
}
.hero h1 { font-size: 34px; letter-spacing: 1px; margin-bottom: 10px; font-weight: 700; }
.hero .sub { color: rgba(255,255,255,0.78); font-size: 16px; max-width: 720px; margin-bottom: 26px; }
.hero-actions { display: flex; gap: 10px; flex-wrap: wrap; }
.btn {
  display: inline-block; text-decoration: none; font-size: 14.5px;
  padding: 9px 18px; border-radius: 8px; transition: all 0.18s;
}
.btn-primary { background: #fff; color: var(--navy-900); font-weight: 600; }
.btn-primary:hover { background: var(--blue-100); }
.btn-ghost { border: 1px solid rgba(255,255,255,0.35); color: #fff; }
.btn-ghost:hover { background: rgba(255,255,255,0.1); }

/* 统计条 */
.stat-band {
  display: grid; grid-template-columns: repeat(4, 1fr);
  gap: 1px; background: var(--line);
  border: 1px solid var(--line); border-radius: var(--radius);
  overflow: hidden; margin-top: -26px; position: relative; z-index: 2;
  box-shadow: var(--shadow);
}
.stat-band .stat { background: #fff; padding: 16px 20px; }
.stat-band .stat-num { font-size: 24px; font-weight: 700; color: var(--navy-800); line-height: 1.3; }
.stat-band .stat-label { font-size: 12.5px; color: var(--ink-soft); }

/* ===== 主体 ===== */
.page-main { padding: 30px 0 56px; }
.section-title {
  font-size: 21px; color: var(--navy-900); font-weight: 700;
  margin: 38px 0 8px; padding-left: 12px; border-left: 4px solid var(--blue-600);
}
.section-title:first-child { margin-top: 0; }
.section-desc { font-size: 14px; color: var(--ink-soft); margin: 0 0 16px 16px; }
.group-label {
  font-size: 13px; letter-spacing: 2px; color: var(--blue-700);
  font-weight: 700; margin: 26px 0 12px; text-transform: uppercase;
}

.card-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 16px; }
.card {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 18px 20px; box-shadow: var(--shadow);
}
.card h3 { font-size: 16px; color: var(--navy-900); margin-bottom: 8px; }
.card p { font-size: 14px; color: var(--ink-soft); }
.card .big { font-size: 25px; font-weight: 700; color: var(--blue-700); margin-bottom: 2px; }

/* 入口卡 */
.entry-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; margin-top: 4px; }
.entry {
  display: block; text-decoration: none; color: inherit;
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 22px 22px 18px; box-shadow: var(--shadow);
  transition: transform 0.16s, border-color 0.16s;
}
.entry:hover { transform: translateY(-3px); border-color: var(--blue-500); }
.entry .kicker { font-size: 11.5px; letter-spacing: 2px; color: var(--blue-500); font-weight: 700; }
.entry h3 { font-size: 18px; color: var(--navy-900); margin: 6px 0 8px; }
.entry p { font-size: 14px; color: var(--ink-soft); min-height: 44px; }
.entry .more { font-size: 13.5px; color: var(--blue-700); font-weight: 600; }

/* ===== 表格 ===== */
.table-wrap { overflow-x: auto; background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow); }
table { width: 100%; border-collapse: collapse; font-size: 14.5px; min-width: 560px; }
thead th {
  background: var(--blue-50); color: var(--navy-900); text-align: left;
  padding: 11px 14px; border-bottom: 2px solid var(--blue-100); white-space: nowrap;
}
tbody td { padding: 10px 14px; border-bottom: 1px solid var(--line); vertical-align: top; }
tbody tr:last-child td { border-bottom: none; }
tbody tr:hover { background: #fafcff; }

/* ===== 徽章 ===== */
.badge {
  display: inline-block; font-size: 12px; padding: 2px 9px;
  border-radius: 20px; font-weight: 600; white-space: nowrap;
}
.badge-core { background: #fbeaea; color: var(--red); }
.badge-essay { background: var(--amber-bg); color: var(--amber); }
.badge-req { background: var(--blue-100); color: var(--blue-700); }
.badge-ok { background: var(--green-bg); color: var(--green); }
.badge-plain { background: #eef1f5; color: var(--ink-soft); }

/* ===== 知识域卡片 ===== */
.k-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); gap: 14px; }
.k-card {
  display: block; text-decoration: none; color: inherit; background: #fff;
  border: 1px solid var(--line); border-radius: var(--radius); padding: 18px 20px;
  box-shadow: var(--shadow); transition: transform 0.15s, border-color 0.15s;
  border-top: 3px solid var(--blue-600);
}
.k-card:hover { transform: translateY(-2px); border-color: var(--blue-500); }
.k-card .k-title { font-size: 16.5px; font-weight: 700; color: var(--navy-900); margin-bottom: 6px; }
.k-card .k-desc { font-size: 13.5px; color: var(--ink-soft); }
.k-card .k-meta { margin-top: 10px; display: flex; gap: 6px; flex-wrap: wrap; }

/* ===== 案例 ===== */
.case-list { display: flex; flex-direction: column; gap: 16px; }
.case {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 22px 24px; box-shadow: var(--shadow);
}
.case-head { display: flex; align-items: baseline; gap: 12px; flex-wrap: wrap; margin-bottom: 4px; }
.case-no { font-size: 13px; font-weight: 700; color: var(--blue-500); letter-spacing: 1px; }
.case h3 { font-size: 18px; color: var(--navy-900); }
.case .scene { font-size: 14px; color: var(--ink-soft); margin: 6px 0 12px; }
.case h4 { font-size: 13px; color: var(--blue-700); letter-spacing: 1px; margin: 14px 0 6px; font-weight: 700; }
.case ul { padding-left: 20px; font-size: 14.2px; }
.case li { margin: 4px 0; }
.case .tradeoff {
  background: var(--blue-50); border-left: 3px solid var(--blue-500);
  padding: 10px 14px; border-radius: 0 8px 8px 0; font-size: 14px; margin-top: 12px;
}

/* ===== 计划 ===== */
.week-item {
  display: flex; gap: 14px; align-items: flex-start; background: #fff;
  border: 1px solid var(--line); border-radius: var(--radius);
  padding: 14px 18px; margin-bottom: 10px; box-shadow: var(--shadow);
}
.week-item input[type="checkbox"] {
  width: 20px; height: 20px; margin-top: 4px; accent-color: var(--blue-600);
  cursor: pointer; flex-shrink: 0;
}
.week-item.done .week-title { text-decoration: line-through; color: var(--ink-soft); }
.week-item.current { border-color: var(--blue-500); box-shadow: 0 0 0 3px rgba(46,125,209,0.1); }
.week-item .week-title { font-weight: 700; color: var(--navy-900); }
.week-item .week-detail { font-size: 14px; color: var(--ink-soft); }
.week-now {
  font-size: 11px; background: var(--blue-600); color: #fff;
  padding: 1px 7px; border-radius: 10px; margin-left: 6px; vertical-align: 2px;
}
.progress-bar { height: 10px; background: var(--blue-100); border-radius: 10px; overflow: hidden; margin: 6px 0 8px; }
.progress-bar .fill { height: 100%; background: linear-gradient(90deg, var(--blue-600), var(--blue-500)); border-radius: 10px; transition: width 0.4s; }

/* ===== 章节导航 ===== */
.ch-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(310px, 1fr)); gap: 14px; }
.ch-card {
  display: block; background: #fff; border: 1px solid var(--line);
  border-radius: var(--radius); padding: 16px 18px; text-decoration: none;
  color: inherit; box-shadow: var(--shadow);
  transition: transform 0.15s, border-color 0.15s;
}
.ch-card:hover { transform: translateY(-2px); border-color: var(--blue-500); }
.ch-card .ch-no { font-size: 12px; font-weight: 700; color: var(--blue-500); letter-spacing: 1px; }
.ch-card .ch-title { font-size: 16px; font-weight: 700; color: var(--navy-900); margin: 4px 0 6px; }
.ch-card .ch-meta { font-size: 13px; color: var(--ink-soft); }
.ch-card .badges { margin-top: 8px; display: flex; gap: 6px; flex-wrap: wrap; }

/* ===== 章节正文 ===== */
.chapter-page {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  box-shadow: var(--shadow); padding: 30px 36px; max-width: 900px; margin: 0 auto;
}
.chapter-page h1 {
  color: var(--navy-900); font-size: 26px; margin-bottom: 6px;
  padding-bottom: 14px; border-bottom: 2px solid var(--blue-100);
}
.chapter-page h2 {
  color: #1a4a85; font-size: 20px; margin: 26px 0 12px;
  padding-left: 10px; border-left: 4px solid var(--blue-500);
}
.chapter-page h3 { color: var(--blue-700); font-size: 17px; margin: 20px 0 10px; }
.chapter-page ul, .chapter-page ol { padding-left: 24px; margin: 8px 0; }
.chapter-page li { margin: 4px 0; }
.chapter-page blockquote {
  background: var(--blue-50); border-left: 4px solid var(--blue-500);
  padding: 10px 16px; border-radius: 0 8px 8px 0; margin: 12px 0;
  color: var(--ink); font-size: 14.5px;
}
.chapter-page code { background: var(--blue-50); padding: 1px 6px; border-radius: 4px; font-size: 0.9em; color: var(--navy-900); }
.chapter-page pre { background: #f0f5fb; border: 1px solid var(--line); border-radius: 8px; padding: 14px; overflow-x: auto; margin: 12px 0; }
.chapter-page pre code { background: none; padding: 0; }
.chapter-page table { min-width: 480px; margin: 12px 0; }
.chapter-page hr { border: none; border-top: 1px solid var(--line); margin: 22px 0; }
.ch-nav { display: flex; justify-content: space-between; gap: 12px; margin-top: 26px; }
.ch-nav a {
  color: var(--blue-700); text-decoration: none; font-size: 14.5px;
  padding: 8px 14px; background: var(--blue-50); border-radius: 8px;
}
.ch-nav a:hover { background: var(--blue-100); }

/* ===== 提示条 ===== */
.notice { border-radius: var(--radius); padding: 14px 18px; font-size: 14.5px; margin-bottom: 18px; border: 1px solid; }
.notice-warn { background: var(--amber-bg); border-color: #ecd9b0; color: #6f4c10; }
.notice-info { background: var(--blue-50); border-color: var(--blue-100); color: var(--navy-800); }

/* ===== 更新列表 ===== */
.update-list { list-style: none; }
.update-list li {
  display: flex; gap: 14px; padding: 10px 0; border-bottom: 1px dashed var(--line);
  font-size: 14.5px;
}
.update-list li:last-child { border-bottom: none; }
.update-list .date { color: var(--ink-soft); font-size: 13px; white-space: nowrap; font-variant-numeric: tabular-nums; }

/* ===== 倒计时 ===== */
.countdown-box {
  display: inline-flex; gap: 12px; align-items: center;
  background: rgba(255,255,255,0.08); border: 1px solid rgba(255,255,255,0.22);
  border-radius: var(--radius); padding: 12px 20px;
}
.countdown-box .unit { text-align: center; min-width: 46px; }
.countdown-box .num { font-size: 26px; font-weight: 700; font-variant-numeric: tabular-nums; }
.countdown-box .label { font-size: 11.5px; color: rgba(255,255,255,0.7); }
.countdown-box .sep { font-size: 20px; opacity: 0.5; }

/* ===== 页脚 ===== */
.site-footer { background: var(--navy-900); color: rgba(255,255,255,0.62); padding: 28px 0; margin-top: 40px; font-size: 13px; }
.site-footer .container { display: flex; flex-direction: column; gap: 6px; }
.site-footer a { color: rgba(255,255,255,0.82); text-decoration: none; }
.site-footer a:hover { text-decoration: underline; }
.site-footer .foot-row { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 8px; }
.site-footer .copy { color: rgba(255,255,255,0.4); }

@media (max-width: 820px) {
  .entry-grid { grid-template-columns: 1fr; }
  .stat-band { grid-template-columns: repeat(2, 1fr); }
  .hero h1 { font-size: 26px; }
  .hero { padding: 40px 0 38px; }
  .chapter-page { padding: 20px 18px; }
}
@media (max-width: 520px) {
  .brand-sub { display: none; }
  .main-nav a { padding: 6px 9px; font-size: 13.5px; }
}