/* ============================================================
   深度行动® · 首都都市圈网（首圈网） SDquan.com
   全局样式 / 设计系统
   配色：深蓝 #0E2A47 · 中国红 #C8102E · 金 #C9A35B · 蓝 #1B5FA8
   ============================================================ */

:root {
  --c-navy:   #0E2A47;   /* 主色·深蓝（权威/专业） */
  --c-navy-2: #143a63;
  --c-blue:   #1B5FA8;   /* 辅助蓝 */
  --c-blue-2: #2C77C4;
  --c-red:    #C8102E;   /* 中国红·强调 */
  --c-red-2:  #E0334B;
  --c-gold:   #C9A35B;   /* 金 */
  --c-gold-2: #B8902F;
  --c-ink:    #1A1F29;   /* 正文 */
  --c-gray:   #5A6472;   /* 次级文字 */
  --c-gray-2: #8A93A2;
  --c-line:   #E4E8EF;
  --c-bg:     #F5F7FA;   /* 浅灰底 */
  --c-white:  #FFFFFF;

  --maxw: 1200px;
  --radius: 14px;
  --radius-sm: 10px;
  --shadow: 0 10px 30px rgba(14,42,71,.08);
  --shadow-lg: 0 18px 50px rgba(14,42,71,.14);
  --font: "Microsoft YaHei","PingFang SC","Hiragino Sans GB","Source Han Sans SC",sans-serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  color: var(--c-ink);
  background: var(--c-bg);
  line-height: 1.75;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }

.container { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

/* ---------- 通用按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 13px 28px; border-radius: 999px; font-weight: 600;
  font-size: 15px; transition: .25s; cursor: pointer; border: 0;
}
.btn-primary { background: var(--c-red); color: #fff; box-shadow: 0 8px 20px rgba(200,16,46,.28); }
.btn-primary:hover { background: var(--c-red-2); transform: translateY(-2px); }
.btn-ghost { background: rgba(255,255,255,.14); color: #fff; border: 1px solid rgba(255,255,255,.55); }
.btn-ghost:hover { background: rgba(255,255,255,.24); }
.btn-dark { background: var(--c-navy); color: #fff; }
.btn-dark:hover { background: var(--c-navy-2); transform: translateY(-2px); }

/* ---------- 头部导航 ---------- */
.header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255,255,255,.96);
  backdrop-filter: saturate(180%) blur(10px);
  border-bottom: 1px solid var(--c-line);
}
.header .container { max-width: 1340px; }
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 150px; }
.brand { display: flex; align-items: center; gap: 12px; }
.brand img { height: 126px; width: auto; }
.brand-text { display: none; }
.nav { display: flex; align-items: center; gap: 2px; }
.nav a {
  padding: 10px 12px; border-radius: 8px; font-size: 22.5px; font-weight: 500;
  color: var(--c-gray); transition: .2s; white-space: nowrap;
}
.nav a:hover { color: var(--c-navy); background: var(--c-bg); }
.nav a.active { color: var(--c-red); background: rgba(200,16,46,.08); font-weight: 600; }
.nav-cta { margin-left: 8px; }

.hamburger { display: none; flex-direction: column; gap: 5px; background: none; border: 0; cursor: pointer; padding: 8px; }
.hamburger span { width: 24px; height: 2px; background: var(--c-navy); border-radius: 2px; transition: .3s; }

/* ---------- Hero ---------- */
.hero {
  position: relative; overflow: hidden;
  background:
    radial-gradient(1200px 500px at 80% -10%, rgba(43,119,196,.45), transparent 60%),
    linear-gradient(135deg, var(--c-navy) 0%, #0a1f38 55%, #0d2747 100%);
  color: #fff; padding: 92px 0 110px;
}
.hero-skyline { position: absolute; left: 0; right: 0; bottom: 0; width: 100%; opacity: .5; }
.hero .container { position: relative; z-index: 2; }
.hero-badge {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 7px 16px; border-radius: 999px; font-size: 13px; font-weight: 600;
  background: rgba(201,163,91,.18); color: var(--c-gold);
  border: 1px solid rgba(201,163,91,.4); margin-bottom: 22px;
}
.hero h1 { font-size: 46px; line-height: 1.2; font-weight: 800; letter-spacing: 1px; }
.hero h1 .accent { color: var(--c-gold); }
.hero p.lead { font-size: 18px; color: #cdd8e8; margin: 20px 0 32px; max-width: 640px; }
.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; }

/* ---------- 区块通用 ---------- */
.section { padding: 84px 0; }
.section-head { text-align: center; max-width: 720px; margin: 0 auto 48px; }
.section-tag { color: var(--c-red); font-weight: 700; font-size: 14px; letter-spacing: 3px; text-transform: uppercase; }
.section-title { font-size: 32px; font-weight: 800; color: var(--c-navy); margin: 10px 0 14px; }
.section-sub { color: var(--c-gray); font-size: 16px; }
.section.alt { background: var(--c-white); }

/* ---------- 卡片栅格 ---------- */
.grid { display: grid; gap: 24px; }
.grid-3 { grid-template-columns: repeat(3,1fr); }
.grid-4 { grid-template-columns: repeat(4,1fr); }
.grid-2 { grid-template-columns: repeat(2,1fr); }

.card {
  background: var(--c-white); border: 1px solid var(--c-line);
  border-radius: var(--radius); padding: 30px; transition: .25s;
}
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); border-color: transparent; }
.card .ico {
  width: 54px; height: 54px; border-radius: 14px; display: grid; place-items: center;
  background: linear-gradient(135deg,var(--c-blue),var(--c-navy)); color: #fff; margin-bottom: 18px;
}
.card .ico svg { width: 28px; height: 28px; }
.card h3 { font-size: 19px; color: var(--c-navy); margin-bottom: 10px; }
.card p { color: var(--c-gray); font-size: 15px; }

/* ---------- 三圈层 ---------- */
.circle-card { position: relative; overflow: hidden; border-top: 4px solid var(--c-blue); }
.circle-card .num { position: absolute; top: 18px; right: 22px; font-size: 46px; font-weight: 800; color: rgba(14,42,71,.07); }
.circle-card h3 { display: flex; align-items: center; gap: 10px; }
.circle-card .tag { font-size: 12px; padding: 3px 10px; border-radius: 999px; background: rgba(27,95,168,.1); color: var(--c-blue); font-weight: 600; }

/* ---------- 数据统计 ---------- */
.stats { background: linear-gradient(135deg,var(--c-navy),#0a1f38); color: #fff; }
.stats .grid { text-align: center; }
.stat .n { font-size: 44px; font-weight: 800; color: var(--c-gold); line-height: 1.1; }
.stat .l { color: #b9c6da; margin-top: 8px; font-size: 15px; }

/* ---------- 简介双栏 ---------- */
.split { display: grid; grid-template-columns: 1fr 1fr; gap: 56px; align-items: center; }
.split h2 { font-size: 30px; color: var(--c-navy); margin-bottom: 18px; font-weight: 800; }
.split p { color: var(--c-gray); margin-bottom: 16px; }
.split .emoji-list li { display: flex; gap: 10px; align-items: flex-start; margin-bottom: 12px; color: var(--c-ink); }
.split .emoji-list .dot { color: var(--c-red); font-weight: 700; }
.intro-visual {
  background: linear-gradient(135deg,var(--c-blue),var(--c-navy));
  border-radius: 20px; padding: 36px; color: #fff; box-shadow: var(--shadow-lg);
}
.intro-visual .map-rings { display: grid; place-items: center; gap: 0; }
.ring { border: 1px dashed rgba(255,255,255,.5); border-radius: 50%; display: grid; place-items: center; color: #fff; font-size: 13px; font-weight: 600; }

/* ---------- 资讯列表 ---------- */
.news-card { display: flex; flex-direction: column; }
.news-card .date { color: var(--c-gold-2); font-size: 13px; font-weight: 600; margin-bottom: 8px; }
.news-card h3 { font-size: 18px; color: var(--c-navy); margin-bottom: 10px; line-height: 1.5; }
.news-card p { color: var(--c-gray); font-size: 14px; flex: 1; }
.news-card .more { margin-top: 16px; color: var(--c-red); font-weight: 600; font-size: 14px; }

/* ---------- 面包屑 ---------- */
.crumb { background: var(--c-white); border-bottom: 1px solid var(--c-line); padding: 16px 0; font-size: 14px; color: var(--c-gray); }
.crumb a:hover { color: var(--c-red); }

/* ---------- 内页 Hero ---------- */
.page-hero { background: linear-gradient(135deg,var(--c-navy),#0a1f38); color: #fff; padding: 64px 0; }
.page-hero h1 { font-size: 36px; font-weight: 800; }
.page-hero p { color: #cdd8e8; margin-top: 10px; max-width: 720px; }

/* ---------- 关于/正文 ---------- */
.prose { max-width: 820px; margin: 0 auto; }
.prose h2 { font-size: 24px; color: var(--c-navy); margin: 36px 0 14px; }
.prose h3 { font-size: 19px; color: var(--c-blue); margin: 26px 0 10px; }
.prose p { color: var(--c-ink); margin-bottom: 16px; }
.prose .lead-p { font-size: 18px; color: var(--c-gray); }
.prose blockquote {
  border-left: 4px solid var(--c-gold); background: #fbf6ec; padding: 16px 20px;
  border-radius: 0 10px 10px 0; color: var(--c-navy); margin: 20px 0; font-weight: 500;
}
.callout {
  background: var(--c-white); border: 1px solid var(--c-line); border-left: 4px solid var(--c-red);
  border-radius: 10px; padding: 22px 24px; margin: 24px 0; box-shadow: var(--shadow);
}
.callout h4 { color: var(--c-red); margin-bottom: 8px; }

/* ---------- 表单 ---------- */
.form-grid { display: grid; gap: 18px; }
.field label { display: block; font-weight: 600; color: var(--c-navy); margin-bottom: 7px; font-size: 14px; }
.field input, .field textarea, .field select {
  width: 100%; padding: 12px 14px; border: 1px solid var(--c-line); border-radius: 10px;
  font-family: var(--font); font-size: 15px; color: var(--c-ink); background: #fff; transition: .2s;
}
.field input:focus, .field textarea:focus, .field select:focus { outline: none; border-color: var(--c-blue); box-shadow: 0 0 0 3px rgba(27,95,168,.12); }
.field textarea { min-height: 130px; resize: vertical; }

/* ---------- 联系信息 ---------- */
.contact-info li { display: flex; gap: 14px; align-items: flex-start; padding: 14px 0; border-bottom: 1px solid var(--c-line); }
.contact-info .ci { width: 42px; height: 42px; border-radius: 10px; background: rgba(27,95,168,.1); color: var(--c-blue); display: grid; place-items: center; flex: none; }
.contact-info .ci svg { width: 22px; height: 22px; }
.contact-info b { color: var(--c-navy); display: block; }
.contact-info span { color: var(--c-gray); font-size: 14px; }

/* 联系卡片（无表单版） */
.info-card { display: flex; gap: 16px; align-items: flex-start; }
.info-card .ci { width: 48px; height: 48px; border-radius: 12px; background: rgba(27,95,168,.1); color: var(--c-blue); display: grid; place-items: center; flex: none; }
.info-card .ci svg { width: 24px; height: 24px; }
.info-card b { color: var(--c-navy); display: block; font-size: 16px; margin-bottom: 2px; }
.info-card span { color: var(--c-gray); font-size: 14px; }

/* ---------- 页脚 ---------- */
.footer { background: var(--c-navy); color: #cdd8e8; padding: 56px 0 0; }
.footer-grid { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1fr; gap: 36px; }
.footer .f-brand img { height: 138px; margin-bottom: 16px; }
.footer .f-brand p { font-size: 14px; color: #9fb0c9; max-width: 320px; }
.footer h4 { color: #fff; font-size: 15px; margin-bottom: 16px; }
.footer-links a { display: block; padding: 6px 0; color: #9fb0c9; font-size: 14px; transition: .2s; }
.footer-links a:hover { color: var(--c-gold); }
.footer-bottom {
  text-align: center; padding: 24px 0; margin-top: 40px;
  border-top: 1px solid rgba(255,255,255,.12);
}
.footer-bottom .row { color: #9fb0c9; font-size: 13.5px; line-height: 2; }
.footer-bottom .row a { color: #cdd8e8; }
.footer-bottom .row a:hover { color: var(--c-gold); }

/* ---------- 返回顶部 ---------- */
.totop {
  position: fixed; right: 22px; bottom: 22px; width: 46px; height: 46px; border-radius: 50%;
  background: var(--c-red); color: #fff; border: 0; cursor: pointer; display: grid; place-items: center;
  box-shadow: var(--shadow-lg); opacity: 0; visibility: hidden; transition: .3s; z-index: 90;
}
.totop.show { opacity: 1; visibility: visible; }
.totop:hover { background: var(--c-red-2); }

/* ---------- 三圈层下拉导航 ---------- */
.nav-drop { position: relative; }
.drop-toggle { cursor: pointer; }
.drop-toggle .caret { font-style: normal; font-size: 11px; display: inline-block; transition: transform .2s; }
.nav-drop:hover .caret, .nav-drop.open .caret { transform: rotate(180deg); }
.dropdown {
  position: absolute; top: calc(100% + 10px); left: 50%; transform: translateX(-50%);
  background: var(--c-white); border: 1px solid var(--c-line); border-radius: 12px;
  box-shadow: var(--shadow-lg); padding: 8px; min-width: 200px;
  display: none; z-index: 80;
}
.dropdown::before { content: ""; position: absolute; top: -12px; left: 0; right: 0; height: 12px; }
.nav-drop:hover .dropdown, .nav-drop.open .dropdown { display: block; }
.dropdown a { display: block; padding: 10px 14px; border-radius: 8px; font-weight: 600; color: var(--c-navy); white-space: nowrap; }
.dropdown a:hover { background: var(--c-bg); color: var(--c-red); }
.dropdown a.active { color: var(--c-red); background: rgba(200,16,46,.08); }

/* ---------- 圈层栏目页 ---------- */
.circle-figure {
  position: relative; border-radius: 18px; overflow: hidden;
  border: 1px solid var(--c-line); box-shadow: var(--shadow-lg); background: #fff;
}
.circle-figure img { width: 100%; height: auto; }
.circle-figure figcaption {
  position: absolute; left: 0; right: 0; bottom: 0; padding: 40px 18px 12px;
  background: linear-gradient(transparent, rgba(14,42,71,.78));
  color: #fff; font-size: 13px;
}
.fact-chips { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 16px; }
.fact-chips span {
  padding: 7px 14px; border-radius: 999px; font-size: 13.5px; font-weight: 600;
  background: rgba(27,95,168,.08); color: var(--c-blue); border: 1px solid rgba(27,95,168,.18);
}

/* ---------- 响应式 ---------- */
@media (max-width: 980px) {
  .grid-3, .grid-4 { grid-template-columns: repeat(2,1fr); }
  .split { grid-template-columns: 1fr; gap: 32px; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 760px) {
  .nav {
    position: fixed; top: 150px; left: 0; right: 0; background: #fff; flex-direction: column;
    align-items: stretch; padding: 16px 24px 24px; gap: 4px; border-bottom: 1px solid var(--c-line);
    transform: translateY(-130%); transition: .3s; box-shadow: var(--shadow);
  }
  .nav.open { transform: translateY(0); }
  .nav a { padding: 13px 14px; }
  .nav-cta { margin: 8px 0 0; }
  .nav .dropdown { position: static; transform: none; box-shadow: none; border: 0; padding: 2px 0 2px 14px; min-width: 0; }
  .nav .dropdown::before { display: none; }
  .nav-drop.open .dropdown { display: block; }
  .dropdown a { padding: 12px 14px; }
  .circle-figure figcaption { position: static; background: rgba(14,42,71,.85); padding: 10px 14px; }
  .hamburger { display: flex; }
  .header-inner { height: 118px; }
  .brand img { height: 96px; }
  .nav { top: 118px; }
  .hero h1 { font-size: 32px; }
  .hero p.lead { font-size: 16px; }
  .section { padding: 60px 0; }
  .section-title { font-size: 26px; }
  .grid-3, .grid-4, .grid-2 { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; gap: 28px; }
}