/* ==========================================================================
   堂堂网 · Tangtang — 官网样式
   设计方向：简约商务 × 精致编辑风（暖纸色 + 深藏青 + 香槟金缎带）
   ========================================================================== */

/* ---------- Design Tokens ---------- */
:root {
  /* 色板 */
  --navy-950: #0d1b2c;
  --navy-900: #13263d;
  --navy-800: #1a3252;
  --navy-700: #1f3a5f;   /* 主色 */
  --navy-600: #2e5e8c;
  --gold-600: #a87c33;
  --gold-500: #b98a3e;   /* 缎带金 */
  --gold-400: #c9a24b;
  --gold-100: #f3e7cf;

  --cream: #faf7f1;      /* 暖纸底 */
  --cream-deep: #f2ede2;
  --paper: #ffffff;
  --line: #e6dfd1;
  --line-soft: #efe9dd;

  --ink: #1c1c1c;
  --ink-soft: #46423a;
  --muted: #837b6d;

  /* 字体 */
  --font-display: "Songti SC", "STSong", "Noto Serif SC", "SimSun", Georgia, "Times New Roman", serif;
  --font-body: "PingFang SC", "Microsoft YaHei", "Segoe UI", "Helvetica Neue", Arial, sans-serif;
  --font-en-display: Georgia, "Times New Roman", "Songti SC", serif;

  /* 尺寸 */
  --container: 1120px;
  --radius: 6px;
  --radius-lg: 14px;
  --shadow-sm: 0 1px 2px rgba(19, 38, 61, 0.06);
  --shadow-md: 0 12px 30px -12px rgba(19, 38, 61, 0.18);
  --shadow-lg: 0 24px 60px -20px rgba(19, 38, 61, 0.28);

  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

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

body {
  font-family: var(--font-body);
  color: var(--ink);
  background-color: var(--cream);
  line-height: 1.7;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  /* 细腻纸纹颗粒 */
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='120' height='120'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.035'/%3E%3C/svg%3E");
}

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

/* ---------- 双语显隐（CSS 驱动，英文真实存在于源码） ---------- */
html[lang="en"] .lang-zh { display: none !important; }
html[lang="zh"] .lang-en { display: none !important; }
/* 默认英文 */
html:not([lang]) .lang-zh { display: none !important; }

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

.section { padding: 88px 0; }
.section--tint { background: var(--cream-deep); }
.section--paper { background: var(--paper); }

/* 缎带分隔线 */
.rule-gold {
  width: 56px; height: 3px;
  background: linear-gradient(90deg, var(--gold-500), var(--gold-400));
  border-radius: 2px;
}

/* 区块标题 */
.section-head { max-width: 640px; margin-bottom: 48px; }
.section-head--center { margin-left: auto; margin-right: auto; text-align: center; }
.section-head--center .rule-gold { margin: 0 auto 20px; }

.eyebrow {
  display: inline-flex; align-items: center; gap: 10px;
  font-size: 12px; letter-spacing: 0.22em; text-transform: uppercase;
  font-weight: 600; color: var(--gold-600);
  margin-bottom: 14px;
}
.eyebrow::before { content: ""; width: 22px; height: 1px; background: var(--gold-500); }
.section-head--center .eyebrow::after { content: ""; width: 22px; height: 1px; background: var(--gold-500); }

.section-title {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: clamp(26px, 4vw, 38px);
  line-height: 1.25;
  color: var(--navy-900);
  letter-spacing: 0.01em;
}
.section-lead { margin-top: 14px; color: var(--muted); font-size: 16px; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 10px;
  padding: 13px 26px; border-radius: var(--radius);
  font-size: 15px; font-weight: 600; letter-spacing: 0.01em;
  border: 1px solid transparent; cursor: pointer;
  transition: transform .25s var(--ease), box-shadow .25s var(--ease),
              background-color .25s var(--ease), color .25s var(--ease), border-color .25s var(--ease);
}
.btn:active { transform: translateY(1px); }
.btn--primary { background: var(--navy-700); color: #fff; box-shadow: var(--shadow-sm); }
.btn--primary:hover { background: var(--navy-800); box-shadow: var(--shadow-md); transform: translateY(-2px); }
.btn--gold { background: var(--gold-500); color: #fff; }
.btn--gold:hover { background: var(--gold-600); transform: translateY(-2px); box-shadow: var(--shadow-md); }
.btn--ghost { background: transparent; color: var(--navy-700); border-color: var(--line); }
.btn--ghost:hover { border-color: var(--navy-700); background: var(--paper); }
.btn .arrow { transition: transform .25s var(--ease); }
.btn:hover .arrow { transform: translateX(3px); }

/* ---------- Header / Nav ---------- */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(250, 247, 241, 0.85);
  backdrop-filter: saturate(160%) blur(10px);
  border-bottom: 1px solid var(--line-soft);
}
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 72px; }

.brand { display: flex; align-items: center; gap: 12px; }
.brand-mark { width: 40px; height: 40px; flex: none; }
.brand-text { display: flex; flex-direction: column; line-height: 1.15; }
.brand-name { font-family: var(--font-display); font-weight: 700; font-size: 19px; color: var(--navy-900); letter-spacing: 0.02em; }
.brand-sub { font-size: 10.5px; letter-spacing: 0.14em; text-transform: uppercase; color: var(--muted); font-weight: 500; }

.site-nav { display: flex; align-items: center; gap: 6px; }
.site-nav a {
  position: relative; padding: 8px 14px; font-size: 15px; font-weight: 500; color: var(--ink-soft);
  border-radius: var(--radius); transition: color .2s var(--ease), background-color .2s var(--ease);
}
.site-nav a:hover { color: var(--navy-700); background: rgba(31, 58, 95, 0.05); }
.site-nav a.is-active { color: var(--navy-700); font-weight: 600; }
.site-nav a.is-active::after {
  content: ""; position: absolute; left: 14px; right: 14px; bottom: 2px; height: 2px;
  background: var(--gold-500); border-radius: 2px;
}

.nav-actions { display: flex; align-items: center; gap: 12px; }

.lang-switch {
  display: flex; align-items: center; border: 1px solid var(--line); border-radius: 999px;
  padding: 3px; background: var(--paper);
}
.lang-switch button {
  border: none; background: transparent; cursor: pointer;
  padding: 4px 12px; font-size: 13px; font-weight: 600; color: var(--muted);
  border-radius: 999px; transition: all .2s var(--ease);
}
.lang-switch button.is-on { background: var(--navy-700); color: #fff; }

.nav-toggle { display: none; border: 1px solid var(--line); background: var(--paper); border-radius: var(--radius); width: 40px; height: 40px; cursor: pointer; }
.nav-toggle span { display: block; width: 18px; height: 2px; background: var(--navy-700); margin: 4px auto; border-radius: 2px; transition: all .25s var(--ease); }
.nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(6px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

/* ---------- Hero ---------- */
.hero { position: relative; overflow: hidden; background: var(--navy-900); color: #fff; }
.hero::before {
  content: ""; position: absolute; inset: 0;
  background:
    radial-gradient(1000px 480px at 85% -10%, rgba(201, 162, 75, 0.16), transparent 60%),
    radial-gradient(700px 500px at 0% 100%, rgba(46, 94, 140, 0.25), transparent 55%);
  pointer-events: none;
}
.hero::after {
  content: ""; position: absolute; inset: 0;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='140' height='140'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.8' numOctaves='2'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.05'/%3E%3C/svg%3E");
  pointer-events: none;
}
.hero-inner {
  position: relative; display: grid; grid-template-columns: 1.1fr 0.9fr; gap: 48px; align-items: center;
  padding: 96px 0 108px;
}
.hero-eyebrow {
  display: inline-flex; align-items: center; gap: 12px;
  font-size: 12px; letter-spacing: 0.24em; text-transform: uppercase; font-weight: 600; color: var(--gold-400);
  margin-bottom: 22px;
}
.hero-eyebrow::before { content: ""; width: 26px; height: 1px; background: var(--gold-400); }
.hero h1 {
  font-family: var(--font-display); font-weight: 600;
  font-size: clamp(32px, 5.4vw, 54px); line-height: 1.18; letter-spacing: 0.01em;
  margin-bottom: 22px;
}
.hero h1 .accent { color: var(--gold-400); }
.hero-lead { font-size: 17px; line-height: 1.8; color: rgba(255, 255, 255, 0.78); max-width: 500px; margin-bottom: 34px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; }
.hero .btn--ghost { color: #fff; border-color: rgba(255, 255, 255, 0.35); }
.hero .btn--ghost:hover { border-color: #fff; background: rgba(255, 255, 255, 0.08); }

.hero-aside { position: relative; }
.hero-card {
  position: relative; background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.12); border-radius: var(--radius-lg);
  padding: 30px; backdrop-filter: blur(6px);
  box-shadow: var(--shadow-lg);
}
.hero-card .gold-ribbon {
  position: absolute; top: -8px; left: 30px; right: 30px; height: 4px;
  background: linear-gradient(90deg, var(--gold-600), var(--gold-400), var(--gold-600));
  border-radius: 2px;
}
.hero-card h2 { font-family: var(--font-display); font-size: 20px; margin-bottom: 6px; letter-spacing: 0.01em; }
.hero-card .stat { font-family: var(--font-en-display); font-size: 40px; font-weight: 700; color: var(--gold-400); line-height: 1; margin: 6px 0 2px; }
.hero-card p { color: rgba(255, 255, 255, 0.7); font-size: 14px; }
.hero-card-list { margin-top: 20px; display: flex; flex-direction: column; gap: 12px; }
.hero-card-list li { display: flex; align-items: center; gap: 12px; font-size: 15px; color: rgba(255, 255, 255, 0.88); }
.hero-card-list .dot { width: 7px; height: 7px; border-radius: 50%; background: var(--gold-400); flex: none; }

/* ---------- Intro / 关于 ---------- */
.split { display: grid; grid-template-columns: 1fr 1fr; gap: 56px; align-items: center; }
.intro-media { position: relative; }
.intro-media .frame {
  border: 1px solid var(--line); border-radius: var(--radius-lg); overflow: hidden; background: var(--paper);
  box-shadow: var(--shadow-md);
}
.intro-media .frame svg { width: 100%; height: auto; }
.intro-media .badge {
  position: absolute; right: -16px; bottom: 28px; background: var(--navy-700); color: #fff;
  padding: 18px 22px; border-radius: var(--radius-lg); box-shadow: var(--shadow-lg);
  max-width: 220px;
}
.intro-media .badge b { display: block; font-family: var(--font-en-display); font-size: 26px; color: var(--gold-400); line-height: 1; margin-bottom: 4px; }
.intro-media .badge span { font-size: 13px; color: rgba(255, 255, 255, 0.82); }

.feature-list { margin-top: 28px; display: flex; flex-direction: column; gap: 18px; }
.feature-list li { display: flex; gap: 16px; align-items: flex-start; }
.feature-list .icon-box {
  width: 44px; height: 44px; flex: none; border-radius: 10px; background: var(--gold-100);
  display: grid; place-items: center; color: var(--gold-600);
}
.feature-list h3 { font-size: 16px; font-weight: 600; color: var(--navy-900); margin-bottom: 3px; }
.feature-list p { font-size: 14.5px; color: var(--muted); }

/* ---------- 经营范围卡片 ---------- */
.cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.card {
  position: relative; background: var(--paper); border: 1px solid var(--line);
  border-radius: var(--radius-lg); padding: 30px 26px; overflow: hidden;
  transition: transform .3s var(--ease), box-shadow .3s var(--ease), border-color .3s var(--ease);
}
.card:hover { transform: translateY(-6px); box-shadow: var(--shadow-md); border-color: var(--gold-400); }
.card .card-icon { width: 52px; height: 52px; border-radius: 12px; display: grid; place-items: center; background: var(--cream-deep); color: var(--navy-700); margin-bottom: 18px; }
.card:hover .card-icon { background: var(--gold-100); color: var(--gold-600); }
.card h3 { font-family: var(--font-display); font-size: 19px; font-weight: 600; color: var(--navy-900); margin-bottom: 8px; }
.card p { font-size: 14.5px; color: var(--muted); }
.card .card-top { position: absolute; top: 0; left: 0; right: 0; height: 3px; background: var(--gold-500); opacity: 0; transition: opacity .3s var(--ease); }
.card:hover .card-top { opacity: 1; }

/* ---------- 数值条 ---------- */
.stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1px; background: var(--line); border: 1px solid var(--line); border-radius: var(--radius-lg); overflow: hidden; }
.stat-cell { background: var(--paper); padding: 34px 22px; text-align: center; }
.stat-cell .num { font-family: var(--font-en-display); font-size: 38px; font-weight: 700; color: var(--navy-700); line-height: 1; }
.stat-cell .num .suffix { color: var(--gold-500); font-size: 24px; }
.stat-cell .label { margin-top: 8px; font-size: 13.5px; color: var(--muted); }

/* ---------- CTA ---------- */
.cta-band { position: relative; overflow: hidden; background: var(--navy-800); color: #fff; border-radius: var(--radius-lg); padding: 56px 48px; }
.cta-band::after { content: ""; position: absolute; inset: 0; background: radial-gradient(600px 300px at 90% 0%, rgba(201, 162, 75, 0.18), transparent 60%); pointer-events: none; }
.cta-band .cta-inner { position: relative; display: flex; align-items: center; justify-content: space-between; gap: 32px; flex-wrap: wrap; }
.cta-band h2 { font-family: var(--font-display); font-size: 28px; font-weight: 600; margin-bottom: 8px; }
.cta-band p { color: rgba(255, 255, 255, 0.72); }

/* ---------- 页面内页 hero ---------- */
.page-hero { background: var(--navy-900); color: #fff; padding: 72px 0 64px; position: relative; overflow: hidden; }
.page-hero::after { content: ""; position: absolute; inset: 0; background: radial-gradient(700px 360px at 85% -20%, rgba(201, 162, 75, 0.15), transparent 60%); pointer-events: none; }
.page-hero .container { position: relative; }
.page-hero h1 { font-family: var(--font-display); font-size: clamp(30px, 4.6vw, 44px); font-weight: 600; margin-bottom: 14px; }
.page-hero .page-hero-sub { color: rgba(255, 255, 255, 0.72); max-width: 620px; font-size: 16px; }
.breadcrumb { margin-top: 22px; display: flex; align-items: center; gap: 10px; font-size: 13.5px; color: rgba(255, 255, 255, 0.55); }
.breadcrumb a:hover { color: var(--gold-400); }
.breadcrumb .sep { opacity: 0.5; }

/* ---------- 经营范围详情 ---------- */
.scope-list { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.scope-item {
  display: flex; gap: 16px; align-items: flex-start; background: var(--paper);
  border: 1px solid var(--line); border-radius: var(--radius-lg); padding: 22px 24px;
  transition: border-color .25s var(--ease), box-shadow .25s var(--ease);
}
.scope-item:hover { border-color: var(--gold-400); box-shadow: var(--shadow-sm); }
.scope-item .idx { font-family: var(--font-en-display); font-size: 15px; color: var(--gold-500); font-weight: 700; line-height: 1.6; }
.scope-item h3 { font-size: 16.5px; font-weight: 600; color: var(--navy-900); margin-bottom: 4px; }
.scope-item p { font-size: 14px; color: var(--muted); }

/* ---------- 政策 / 文档排版 ---------- */
.prose { max-width: 800px; }
.prose h2 { font-family: var(--font-display); font-size: 24px; font-weight: 600; color: var(--navy-900); margin: 40px 0 14px; padding-left: 16px; border-left: 3px solid var(--gold-500); }
.prose h2:first-child { margin-top: 0; }
.prose h3 { font-size: 17px; font-weight: 600; color: var(--navy-800); margin: 26px 0 10px; }
.prose p { color: var(--ink-soft); margin-bottom: 14px; }
.prose ul { margin: 0 0 16px 20px; list-style: disc; }
.prose ul li { margin-bottom: 8px; color: var(--ink-soft); }
.prose .updated { font-size: 13.5px; color: var(--muted); margin-bottom: 8px; }
.prose .doc-note { background: var(--cream-deep); border: 1px solid var(--line); border-radius: var(--radius); padding: 16px 18px; font-size: 14px; color: var(--ink-soft); margin: 22px 0; }

/* ---------- 联系页 ---------- */
.contact-grid { display: grid; grid-template-columns: 1fr 1.1fr; gap: 44px; align-items: start; }
.contact-cards { display: flex; flex-direction: column; gap: 18px; }
.contact-card { display: flex; gap: 18px; background: var(--paper); border: 1px solid var(--line); border-radius: var(--radius-lg); padding: 22px 24px; }
.contact-card .icon-box { width: 48px; height: 48px; flex: none; border-radius: 12px; background: var(--cream-deep); display: grid; place-items: center; color: var(--navy-700); }
.contact-card h3 { font-size: 13px; letter-spacing: 0.08em; text-transform: uppercase; color: var(--muted); font-weight: 600; margin-bottom: 6px; }
.contact-card p { font-size: 16px; color: var(--navy-900); font-weight: 500; }
.contact-card p a:hover { color: var(--gold-600); }
.contact-panel { background: var(--paper); border: 1px solid var(--line); border-radius: var(--radius-lg); padding: 32px 30px; box-shadow: var(--shadow-sm); }
.contact-panel h3 { font-family: var(--font-display); font-size: 21px; color: var(--navy-900); margin-bottom: 6px; }
.contact-panel .hint { font-size: 14px; color: var(--muted); margin-bottom: 22px; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.field { margin-bottom: 16px; }
.field label { display: block; font-size: 13.5px; font-weight: 600; color: var(--navy-800); margin-bottom: 6px; }
.field input, .field textarea {
  width: 100%; padding: 12px 14px; font-size: 15px; font-family: var(--font-body);
  border: 1px solid var(--line); border-radius: var(--radius); background: var(--cream);
  transition: border-color .2s var(--ease), box-shadow .2s var(--ease), background-color .2s var(--ease);
}
.field input:focus, .field textarea:focus { outline: none; border-color: var(--navy-600); background: #fff; box-shadow: 0 0 0 3px rgba(46, 94, 140, 0.12); }
.field textarea { resize: vertical; min-height: 120px; }

/* ---------- Footer ---------- */
.site-footer { background: var(--navy-950); color: rgba(255, 255, 255, 0.72); padding: 64px 0 32px; }
.footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1.2fr; gap: 40px; padding-bottom: 40px; border-bottom: 1px solid rgba(255, 255, 255, 0.1); }
.footer-brand .brand-name { color: #fff; }
.footer-brand .brand-sub { color: rgba(255, 255, 255, 0.5); }
.footer-brand .blurb { margin-top: 16px; font-size: 14px; color: rgba(255, 255, 255, 0.6); max-width: 320px; }
.footer-col h4 { font-size: 13px; letter-spacing: 0.14em; text-transform: uppercase; color: var(--gold-400); margin-bottom: 16px; font-weight: 600; }
.footer-col ul { display: flex; flex-direction: column; gap: 10px; }
.footer-col a { font-size: 14.5px; color: rgba(255, 255, 255, 0.7); transition: color .2s var(--ease); }
.footer-col a:hover { color: #fff; }
.footer-bottom { padding-top: 24px; display: flex; flex-wrap: wrap; gap: 12px; align-items: center; justify-content: space-between; font-size: 13px; color: rgba(255, 255, 255, 0.5); }
.footer-bottom a:hover { color: var(--gold-400); }

/* ---------- 动效 ---------- */
@keyframes rise {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}
.reveal { opacity: 0; animation: rise .8s var(--ease) forwards; }
.reveal.d1 { animation-delay: .08s; }
.reveal.d2 { animation-delay: .16s; }
.reveal.d3 { animation-delay: .24s; }
.reveal.d4 { animation-delay: .32s; }
.reveal.d5 { animation-delay: .4s; }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.001ms !important; animation-iteration-count: 1 !important; transition-duration: 0.001ms !important; }
  html { scroll-behavior: auto; }
  .reveal { opacity: 1 !important; }
}

/* ---------- Responsive ---------- */
@media (max-width: 900px) {
  .section { padding: 64px 0; }
  .hero-inner { grid-template-columns: 1fr; gap: 40px; padding: 64px 0 72px; }
  .hero-aside { max-width: 460px; }
  .split { grid-template-columns: 1fr; gap: 40px; }
  .intro-media .badge { right: 8px; bottom: -20px; }
  .cards { grid-template-columns: repeat(2, 1fr); }
  .stats { grid-template-columns: repeat(2, 1fr); }
  .scope-list { grid-template-columns: 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 680px) {
  .nav-inner { height: 64px; }
  .site-nav {
    position: absolute; top: 64px; left: 0; right: 0; flex-direction: column; align-items: stretch;
    background: var(--paper); border-bottom: 1px solid var(--line); padding: 12px 20px 20px;
    gap: 4px; box-shadow: var(--shadow-md);
    display: none;
  }
  .site-nav.is-open { display: flex; }
  .site-nav a { padding: 12px 14px; }
  .nav-toggle { display: block; }
  .cards { grid-template-columns: 1fr; }
  .hero h1 { font-size: 32px; }
  .cta-band { padding: 40px 26px; }
  .form-row { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; gap: 32px; }
  .stat-cell .num { font-size: 30px; }
}