/* ==========================================================================
   低空视界 —— 全局样式
   纯静态站点，无外部字体/图片/CDN 依赖，离线可直接打开
   ========================================================================== */

/* ---------- 变量 ---------- */
:root {
  --navy: #0d2f5c;
  --navy-dark: #071e3d;
  --blue: #1565c0;
  --blue-soft: #e8f1fb;
  --teal: #00a99d;
  --teal-soft: #e3f7f5;
  --ink: #1f2733;
  --body-text: #4a5568;
  --muted: #7b8794;
  --line: #e2e8f0;
  --bg: #f5f8fc;
  --white: #ffffff;
  --radius: 10px;
  --radius-lg: 14px;
  --shadow-sm: 0 1px 2px rgba(13, 47, 92, .06), 0 4px 12px rgba(13, 47, 92, .05);
  --shadow-md: 0 2px 4px rgba(13, 47, 92, .07), 0 12px 28px rgba(13, 47, 92, .08);
  --wrap: 1140px;
  --font: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
}

/* ---------- 基础重置 ---------- */
* { box-sizing: border-box; }

/* 锚点跳转时避开吸顶导航 */
[id] { scroll-margin-top: 112px; }

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.75;
  color: var(--body-text);
  background: var(--bg);
}

img, svg { max-width: 100%; vertical-align: middle; }

a { color: var(--blue); text-decoration: none; transition: color .18s ease; }
a:hover { color: var(--teal); }

h1, h2, h3, h4 { color: var(--ink); line-height: 1.35; margin: 0 0 .6em; font-weight: 600; }
h1 { font-size: 2rem; }
h2 { font-size: 1.55rem; }
h3 { font-size: 1.15rem; }
p { margin: 0 0 1em; }
ul, ol { margin: 0 0 1em; padding-left: 1.4em; }
li { margin-bottom: .4em; }

.wrap { max-width: var(--wrap); margin: 0 auto; padding: 0 20px; }
.text-center { text-align: center; }

/* 无障碍：跳转到主内容 */
.skip-link {
  position: absolute; left: -9999px; top: 0; z-index: 100;
  background: var(--navy); color: #fff; padding: 10px 16px; border-radius: 0 0 6px 0;
}
.skip-link:focus { left: 0; color: #fff; }

/* ---------- 顶部栏 ---------- */
.topbar {
  background: var(--navy-dark);
  color: #b9c8dd;
  font-size: .82rem;
}
.topbar .wrap {
  display: flex; justify-content: space-between; align-items: center;
  min-height: 36px; gap: 12px; flex-wrap: wrap;
}
.topbar span { display: inline-block; }

/* ---------- 页头 / 导航 ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: var(--navy);
  border-bottom: 3px solid var(--teal);
  box-shadow: 0 2px 12px rgba(7, 30, 61, .18);
}
.site-header .wrap {
  display: flex; align-items: center; justify-content: space-between;
  gap: 16px; min-height: 68px; flex-wrap: wrap;
}
.brand { display: flex; align-items: center; gap: 11px; color: #fff; }
.brand:hover { color: #fff; }
.brand-mark {
  width: 38px; height: 38px; flex: 0 0 38px;
  display: grid; place-items: center;
  background: var(--white);
  border-radius: 9px; padding: 3px;
}
.brand-mark img { width: 100%; height: 100%; object-fit: contain; display: block; }
.brand-text { display: flex; flex-direction: column; line-height: 1.25; }
.brand-name { font-size: 1.18rem; font-weight: 700; letter-spacing: .5px; }
.brand-sub { font-size: .72rem; color: #9db4d4; letter-spacing: 1.4px; }

.site-nav ul {
  display: flex; list-style: none; margin: 0; padding: 0; gap: 4px; flex-wrap: wrap;
}
.site-nav a {
  display: block; padding: 9px 15px; border-radius: 7px;
  color: #d7e3f4; font-size: .95rem; white-space: nowrap;
}
.site-nav a:hover { background: rgba(255, 255, 255, .1); color: #fff; }
.site-nav a.active { background: var(--teal); color: #06303d; font-weight: 600; }

.nav-toggle {
  display: none; background: rgba(255, 255, 255, .12); border: 0; color: #fff;
  padding: 8px 13px; border-radius: 7px; font-size: .9rem; cursor: pointer; font-family: var(--font);
}

/* ---------- 首页主视觉 ---------- */
.hero {
  position: relative; overflow: hidden;
  background: linear-gradient(135deg, var(--navy-dark) 0%, var(--navy) 45%, #14507f 100%);
  color: #dbe6f5;
  padding: 74px 0 66px;
}
.hero::after {
  content: ""; position: absolute; inset: 0; pointer-events: none;
  background-image:
    repeating-linear-gradient(0deg, rgba(255, 255, 255, .045) 0 1px, transparent 1px 46px),
    repeating-linear-gradient(90deg, rgba(255, 255, 255, .045) 0 1px, transparent 1px 46px);
  mask-image: radial-gradient(circle at 78% 30%, #000 0%, transparent 72%);
  -webkit-mask-image: radial-gradient(circle at 78% 30%, #000 0%, transparent 72%);
}
.hero .wrap { position: relative; z-index: 1; }
.hero-tag {
  display: inline-block; margin-bottom: 18px; padding: 5px 14px;
  border: 1px solid rgba(0, 169, 157, .6); border-radius: 40px;
  color: #6fe3d8; font-size: .82rem; letter-spacing: 1px;
}
.hero h1 {
  color: #fff; font-size: 2.35rem; letter-spacing: .5px; margin-bottom: 16px; max-width: 20em;
}
.hero p.lead { font-size: 1.05rem; color: #b9cbe2; max-width: 46em; margin-bottom: 26px; }
.hero-actions { display: flex; gap: 13px; flex-wrap: wrap; }

.btn {
  display: inline-block; padding: 11px 26px; border-radius: 7px;
  font-size: .95rem; font-weight: 600; border: 1px solid transparent; transition: all .18s ease;
}
.btn-primary { background: var(--teal); color: #04333a; }
.btn-primary:hover { background: #21c9ba; color: #04333a; }
.btn-ghost { border-color: rgba(255, 255, 255, .45); color: #e6eefb; }
.btn-ghost:hover { background: rgba(255, 255, 255, .12); color: #fff; }
.btn-outline { border-color: var(--blue); color: var(--blue); background: #fff; }
.btn-outline:hover { background: var(--blue); color: #fff; }

/* ---------- 数据条 ---------- */
.stats {
  background: var(--white); border-bottom: 1px solid var(--line);
}
.stats .wrap {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 0;
  padding-top: 26px; padding-bottom: 26px;
}
.stat { text-align: center; padding: 6px 10px; border-right: 1px dashed var(--line); }
.stat:last-child { border-right: 0; }
.stat b { display: block; font-size: 1.65rem; color: var(--navy); font-weight: 700; line-height: 1.2; }
.stat span { font-size: .86rem; color: var(--muted); }

/* ---------- 区块 ---------- */
.section { padding: 62px 0; }
.section.alt { background: var(--white); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }

.section-head { margin-bottom: 34px; max-width: 46em; }
.section-head.center { margin-left: auto; margin-right: auto; text-align: center; }
.section-head h2 { margin-bottom: .35em; }
.section-head h2::after {
  content: ""; display: block; width: 46px; height: 3px; margin-top: 12px;
  background: linear-gradient(90deg, var(--teal), var(--blue)); border-radius: 2px;
}
.section-head.center h2::after { margin-left: auto; margin-right: auto; }
.section-head p { color: var(--muted); margin: 0; }

/* ---------- 卡片网格 ---------- */
.grid { display: grid; gap: 22px; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

.card {
  background: var(--white); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 26px 24px; box-shadow: var(--shadow-sm); transition: box-shadow .2s ease, transform .2s ease;
}
.card:hover { box-shadow: var(--shadow-md); transform: translateY(-2px); }
.card h3 { margin-bottom: .5em; }
.card p:last-child { margin-bottom: 0; }

.card-icon {
  width: 46px; height: 46px; border-radius: 10px; display: grid; place-items: center;
  background: var(--blue-soft); color: var(--blue); margin-bottom: 16px;
}
.card-icon.teal { background: var(--teal-soft); color: #04786f; }

.card-link { font-size: .9rem; font-weight: 600; }

/* 带序号的能力卡 */
.card-num {
  font-size: 1.6rem; font-weight: 700; color: #cbd8e8; line-height: 1; margin-bottom: 12px;
}

/* ---------- 图文两栏 ---------- */
.split { display: grid; grid-template-columns: 1.05fr .95fr; gap: 44px; align-items: center; }
.split.reverse .split-media { order: 2; }

.panel {
  background: var(--white); border: 1px solid var(--line); border-radius: var(--radius-lg);
  padding: 30px; box-shadow: var(--shadow-sm);
}
.panel h3 { margin-top: 0; }

/* 装饰性图形（纯 CSS，无外部图片） */
.figure {
  position: relative; min-height: 260px; border-radius: var(--radius-lg); overflow: hidden;
  background: linear-gradient(140deg, #0d2f5c, #16639b 60%, #0f8f96);
  display: grid; place-items: center; color: #cfe6ff; text-align: center; padding: 24px;
}
.figure::before {
  content: ""; position: absolute; inset: 0;
  background-image:
    repeating-linear-gradient(0deg, rgba(255, 255, 255, .05) 0 1px, transparent 1px 34px),
    repeating-linear-gradient(90deg, rgba(255, 255, 255, .05) 0 1px, transparent 1px 34px);
}
.figure-inner { position: relative; z-index: 1; }
.figure-inner strong { display: block; font-size: 1.1rem; color: #fff; margin-bottom: 6px; }
.figure-inner span { font-size: .85rem; color: #a9c6e4; }

/* ---------- 列表 ---------- */
.list-check { list-style: none; padding: 0; }
.list-check li { position: relative; padding-left: 26px; margin-bottom: .7em; }
.list-check li::before {
  content: ""; position: absolute; left: 0; top: .55em;
  width: 8px; height: 8px; border-radius: 50%; background: var(--teal);
  box-shadow: 0 0 0 4px rgba(0, 169, 157, .13);
}

/* ---------- 资讯列表 ---------- */
.news-list { list-style: none; padding: 0; margin: 0; }
.news-item {
  display: grid; grid-template-columns: 118px 1fr; gap: 22px;
  padding: 20px 0; border-bottom: 1px solid var(--line);
}
.news-item:first-child { padding-top: 0; }
.news-item:last-child { border-bottom: 0; padding-bottom: 0; }
.news-date {
  background: var(--blue-soft); color: var(--blue); border-radius: var(--radius);
  text-align: center; padding: 10px 6px; align-self: start;
}
.news-date b { display: block; font-size: 1.35rem; line-height: 1.1; }
.news-date span { font-size: .78rem; }
.news-body h3 { font-size: 1.06rem; margin-bottom: .35em; }
.news-body p { margin: 0; color: var(--muted); font-size: .93rem; }
.news-meta { font-size: .8rem; color: var(--muted); margin-top: 6px; }
.tag {
  display: inline-block; padding: 2px 9px; border-radius: 4px; font-size: .75rem;
  background: var(--teal-soft); color: #04786f;
}

/* ---------- 文章正文排版 ---------- */
.article { max-width: 860px; margin: 0 auto; }
.article h2 { margin-top: 1.8em; }
.article h3 { margin-top: 1.5em; }
.article table { width: 100%; border-collapse: collapse; margin: 1.2em 0; font-size: .94rem; }
.article th, .article td { border: 1px solid var(--line); padding: 11px 14px; text-align: left; }
.article th { background: var(--blue-soft); color: var(--navy); font-weight: 600; }
.article blockquote {
  margin: 1.4em 0; padding: 14px 20px; background: var(--white);
  border-left: 4px solid var(--teal); border-radius: 0 var(--radius) var(--radius) 0; color: var(--body-text);
}

/* ---------- 页面标题条 ---------- */
.page-head {
  background: linear-gradient(120deg, var(--navy-dark), #14507f);
  color: #cfe0f5; padding: 46px 0; border-bottom: 3px solid var(--teal);
}
.page-head h1 { color: #fff; margin-bottom: .3em; }
.page-head p { margin: 0; color: #a8c1de; }
.crumb { font-size: .84rem; color: #9db4d4; margin-bottom: 10px; }
.crumb a { color: #cfe0f5; }

/* ---------- 联系方式（静态展示，无提交表单） ---------- */
.info-list { list-style: none; padding: 0; margin: 0; }
.info-list li { display: flex; gap: 14px; padding: 14px 0; border-bottom: 1px dashed var(--line); }
.info-list li:last-child { border-bottom: 0; }
.info-label { flex: 0 0 96px; color: var(--muted); font-size: .9rem; }
.ph { color: #b45309; background: #fef3c7; padding: 1px 6px; border-radius: 4px; font-size: .92rem; }

/* ---------- 提示条 ---------- */
.notice {
  background: var(--white); border: 1px solid var(--line); border-left: 4px solid var(--teal);
  border-radius: 0 var(--radius) var(--radius) 0; padding: 20px 24px; box-shadow: var(--shadow-sm);
}
.notice h3 { margin-top: 0; font-size: 1.05rem; }

/* ---------- 页脚 ---------- */
.site-footer { background: var(--navy-dark); color: #9db4d4; font-size: .9rem; padding: 48px 0 0; }
.footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1.2fr; gap: 34px; }
.site-footer h4 { color: #fff; font-size: .98rem; margin-bottom: .9em; }
.site-footer a { color: #9db4d4; }
.site-footer a:hover { color: var(--teal); }
.site-footer ul { list-style: none; padding: 0; }
.site-footer li { margin-bottom: .5em; }
.footer-brand-name {
  display: flex; align-items: center; gap: 9px;
  color: #fff; font-size: 1.1rem; font-weight: 700; margin-bottom: .6em;
}
.footer-logo {
  width: 26px; height: 26px; flex: 0 0 26px; padding: 2px;
  background: var(--white); border-radius: 7px; object-fit: contain;
}
.footer-bottom {
  margin-top: 40px; border-top: 1px solid rgba(255, 255, 255, .1);
  padding: 18px 0 22px; font-size: .84rem; color: #7d93b1;
}
.footer-bottom .wrap { display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap; }
.footer-bottom a { color: #7d93b1; }

/* ---------- 响应式 ---------- */
@media (max-width: 960px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .split { grid-template-columns: 1fr; gap: 28px; }
  .split.reverse .split-media { order: 0; }
  .footer-grid { grid-template-columns: repeat(2, 1fr); }
  .stats .wrap { grid-template-columns: repeat(2, 1fr); }
  .stat { border-right: 0; border-bottom: 1px dashed var(--line); padding: 12px 10px; }
  .stat:nth-child(odd) { border-right: 1px dashed var(--line); }
  .stat:nth-last-child(-n+2) { border-bottom: 0; }
  .hero h1 { font-size: 1.95rem; }
}

@media (max-width: 680px) {
  .nav-toggle { display: block; }
  .site-nav { display: none; width: 100%; padding-bottom: 14px; }
  .site-nav.open { display: block; }
  .site-nav ul { flex-direction: column; gap: 2px; }
  .site-nav a { padding: 11px 14px; background: rgba(255, 255, 255, .05); }
  .site-header .wrap { min-height: 60px; }

  .hero { padding: 52px 0 46px; }
  .hero h1 { font-size: 1.6rem; }
  .hero p.lead { font-size: .98rem; }
  .section { padding: 44px 0; }
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; gap: 26px; }
  .news-item { grid-template-columns: 1fr; gap: 10px; }
  .news-date { display: inline-block; text-align: left; padding: 6px 12px; }
  .news-date b, .news-date span { display: inline; font-size: .85rem; }
  .info-list li { flex-direction: column; gap: 4px; }
  .info-label { flex: none; }
  h1 { font-size: 1.55rem; }
  h2 { font-size: 1.3rem; }
}

/* ---------- 打印 ---------- */
@media print {
  .site-header, .topbar, .site-footer, .hero-actions { display: none; }
  body { background: #fff; }
}