/* ========================================
   联动势能官网 — 混合风格设计系统
   白底商务为主 + 深色科技感区块点缀
   Mobile-first · 真正响应式
   零外部依赖
   ======================================== */

/* --- Design Tokens --- */
:root {
  /* 品牌主色 — 深海军蓝（商务权威） */
  --navy: #013580;
  --navy-light: #1a4d9c;
  --navy-dark: #002266;

  /* 强调色 — 电光青（克制使用，仅关键CTA/数据/编号） */
  --cyan: #00C8E0;
  --cyan-dark: #00a5bd;
  --cyan-soft: rgba(0, 200, 224, 0.12);

  /* 辅助色 */
  --gold: #C8960C;

  /* 文字 */
  --text: #1a2332;
  --text-secondary: #5a6678;
  --text-light: #8a96a8;
  --text-on-dark: #ffffff;
  --text-on-dark-80: rgba(255, 255, 255, 0.8);
  --text-on-dark-60: rgba(255, 255, 255, 0.6);
  --text-on-dark-40: rgba(255, 255, 255, 0.4);

  /* 背景（白底商务为主） */
  --bg: #ffffff;
  --bg-soft: #f6f8fb;
  --bg-gray: #f1f4f8;
  --bg-dark: #013580;

  /* 边框 */
  --border: #e4e9f0;
  --border-soft: #eef1f6;
  --border-dark: rgba(255, 255, 255, 0.12);

  /* 阴影 */
  --shadow-sm: 0 1px 3px rgba(1, 53, 128, 0.06);
  --shadow-md: 0 4px 16px rgba(1, 53, 128, 0.08);
  --shadow-lg: 0 12px 40px rgba(1, 53, 128, 0.12);
  --shadow-cyan: 0 8px 24px rgba(0, 200, 224, 0.25);

  /* 字体（系统字体栈，零外部依赖） */
  --font-display: -apple-system, BlinkMacSystemFont, "PingFang SC",
                  "Microsoft YaHei", "Hanken Grotesk", "Segoe UI", sans-serif;
  --font-body: -apple-system, BlinkMacSystemFont, "PingFang SC",
               "Microsoft YaHei", "Segoe UI", Roboto, sans-serif;
  --font-mono: "SF Mono", "JetBrains Mono", Consolas, "Liberation Mono", monospace;

  /* 字号阶梯（移动端基准） */
  --fs-xs: 12px;
  --fs-sm: 13px;
  --fs-base: 15px;
  --fs-md: 17px;
  --fs-lg: 20px;
  --fs-h3: 24px;
  --fs-h2: 28px;
  --fs-h1: 34px;
  --fs-display: 42px;

  /* 行高 */
  --lh-tight: 1.2;
  --lh-snug: 1.4;
  --lh: 1.7;
  --lh-loose: 1.8;

  /* 间距（8px基准网格） */
  --sp-xs: 8px;
  --sp-sm: 16px;
  --sp-md: 24px;
  --sp-lg: 40px;
  --sp-xl: 64px;
  --sp-xxl: 96px;

  /* 布局 */
  --page-max: 1200px;
  --page-pad: 20px;
  --read-max: 720px;

  /* 圆角 */
  --radius-sm: 6px;
  --radius: 10px;
  --radius-lg: 16px;
  --radius-pill: 999px;

  /* 动效 */
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --duration: 0.3s;

  /* 导航高度 */
  --nav-h: 56px;
}

/* --- Reset --- */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-h);
}
body {
  font-family: var(--font-body);
  font-size: var(--fs-base);
  font-weight: 400;
  line-height: var(--lh);
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--navy); text-decoration: none; transition: color var(--duration) var(--ease); }
a:hover { color: var(--navy-light); }
button { font-family: inherit; cursor: pointer; }
ul { list-style: none; }

/* --- Typography --- */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  color: var(--text);
  font-weight: 700;
  line-height: var(--lh-tight);
  letter-spacing: -0.01em;
}
h1 { font-size: var(--fs-h1); font-weight: 800; letter-spacing: -0.02em; }
h2 { font-size: var(--fs-h2); }
h3 { font-size: var(--fs-h3); font-weight: 600; }
h4 { font-size: var(--fs-md); font-weight: 600; }
p { margin-bottom: var(--sp-sm); }
p:last-child { margin-bottom: 0; }
strong { font-weight: 600; color: var(--text); }

/* --- Layout --- */
.container {
  width: 100%;
  max-width: var(--page-max);
  margin: 0 auto;
  padding-left: var(--page-pad);
  padding-right: var(--page-pad);
}
.section { padding-top: var(--sp-xl); padding-bottom: var(--sp-xl); }
.section-sm { padding-top: var(--sp-lg); padding-bottom: var(--sp-lg); }
.section-soft { background: var(--bg-soft); }
.section-gray { background: var(--bg-gray); }
.section-dark { background: var(--bg-dark); color: var(--text-on-dark); }
.section-dark h1, .section-dark h2, .section-dark h3, .section-dark h4 { color: var(--text-on-dark); }

/* Section Label */
.section-label { margin-bottom: var(--sp-lg); }
.section-label .overline {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  font-weight: 600;
  letter-spacing: 0.12em;
  color: var(--cyan-dark);
  text-transform: uppercase;
  margin-bottom: var(--sp-xs);
  display: block;
}
.section-label h2 { margin-bottom: 0; }
.section-label .accent-line {
  display: block;
  width: 40px;
  height: 3px;
  background: var(--cyan);
  margin-top: var(--sp-sm);
  border-radius: 2px;
}
.section-dark .section-label .overline { color: var(--cyan); }
.section-dark .section-label .accent-line { background: var(--cyan); }

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  font-family: var(--font-body);
  font-size: var(--fs-sm);
  font-weight: 600;
  padding: 12px 26px;
  letter-spacing: 0.01em;
  border: none;
  border-radius: var(--radius-pill);
  transition: all var(--duration) var(--ease);
  cursor: pointer;
  white-space: nowrap;
}
.btn-primary { background: var(--navy); color: #fff; }
.btn-primary:hover { background: var(--navy-light); color: #fff; transform: translateY(-1px); box-shadow: var(--shadow-md); }
.btn-cyan { background: var(--cyan); color: var(--navy); }
.btn-cyan:hover { background: var(--cyan-dark); color: var(--navy); transform: translateY(-1px); box-shadow: var(--shadow-cyan); }
.btn-outline { background: transparent; color: var(--navy); border: 1.5px solid var(--navy); }
.btn-outline:hover { background: var(--navy); color: #fff; }
.btn-white { background: #fff; color: var(--navy); }
.btn-white:hover { background: var(--bg-soft); color: var(--navy); transform: translateY(-1px); }
.btn-ghost-dark { background: transparent; color: #fff; border: 1.5px solid rgba(255,255,255,0.3); }
.btn-ghost-dark:hover { background: rgba(255,255,255,0.1); color: #fff; border-color: #fff; }
.btn-large { padding: 14px 34px; font-size: var(--fs-base); }
.btn-block { display: flex; width: 100%; }

/* --- Navigation --- */
.site-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--nav-h);
  max-height: var(--nav-h);
  overflow: hidden;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--border-soft);
  transition: box-shadow var(--duration) var(--ease), background var(--duration) var(--ease);
}
.site-nav.scrolled { box-shadow: var(--shadow-sm); }
.nav-inner {
  max-width: var(--page-max);
  height: 100%;
  margin: 0 auto;
  padding: 0 var(--page-pad);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-md);
}
.site-nav .brand {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 800;
  color: var(--navy);
  letter-spacing: -0.02em;
  flex-shrink: 0;
  min-width: 0;
  max-width: 50%;
  overflow: hidden;
}
.site-nav .brand .logo-img {
  height: 24px;
  max-height: 24px;
  width: auto;
  max-width: 80px;
  flex-shrink: 0;
  object-fit: contain;
  display: block;
}
.site-nav .brand span { font-weight: 400; color: var(--text-light); }

/* 移动端 logo 单独约束：防止撑高导航栏 */
@media (max-width: 480px) {
  .site-nav .brand .logo-img {
    height: 20px;
    max-height: 20px;
    max-width: 56px;
  }
  .site-nav .brand {
    gap: 6px;
    font-size: 16px;
    max-width: 60%;
  }
}
.nav-links {
  display: none;
  align-items: center;
  gap: 32px;
}
.nav-links a {
  font-size: var(--fs-sm);
  color: var(--text-secondary);
  font-weight: 500;
  letter-spacing: 0.01em;
  position: relative;
}
.nav-links a:hover, .nav-links a.active { color: var(--navy); }
.nav-links a.active::after {
  content: '';
  position: absolute;
  bottom: -6px;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--cyan);
  border-radius: 1px;
}
.nav-cta {
  font-size: var(--fs-sm);
  font-weight: 600;
  color: #fff;
  background: var(--navy);
  padding: 8px 20px;
  border-radius: var(--radius-pill);
  transition: all var(--duration) var(--ease);
  white-space: nowrap;
}
.nav-cta:hover { background: var(--navy-light); color: #fff; }

/* 汉堡菜单按钮 */
.nav-toggle {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 36px;
  height: 36px;
  background: none;
  border: none;
  padding: 0;
  cursor: pointer;
}
.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--navy);
  border-radius: 2px;
  transition: all var(--duration) var(--ease);
}
.nav-toggle.active span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.active span:nth-child(2) { opacity: 0; }
.nav-toggle.active span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* 移动端抽屉菜单 */
.nav-drawer {
  position: fixed;
  top: 0;
  right: 0;
  width: 100%;
  max-width: 360px;
  height: 100vh;
  background: var(--bg);
  box-shadow: var(--shadow-lg);
  z-index: 1001;
  transform: translateX(100%);
  transition: transform var(--duration) var(--ease-out);
  display: flex;
  flex-direction: column;
  padding: var(--nav-h) var(--page-pad) var(--sp-lg);
  overflow-y: auto;
}
.nav-drawer.open { transform: translateX(0); }
.nav-drawer-overlay {
  position: fixed;
  inset: 0;
  background: rgba(1, 34, 102, 0.4);
  backdrop-filter: blur(2px);
  z-index: 999;
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--duration) var(--ease), visibility var(--duration);
}
.nav-drawer-overlay.open { opacity: 1; visibility: visible; }
.nav-drawer-links { display: flex; flex-direction: column; margin-top: var(--sp-md); }
.nav-drawer-links a {
  font-size: var(--fs-lg);
  font-weight: 600;
  color: var(--text);
  padding: var(--sp-md) 0;
  border-bottom: 1px solid var(--border-soft);
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-drawer-links a:hover { color: var(--navy); }
.nav-drawer-links a .arrow { color: var(--text-light); font-size: var(--fs-md); }
.nav-drawer-cta { margin-top: var(--sp-lg); }
.nav-drawer-info { margin-top: auto; padding-top: var(--sp-lg); font-size: var(--fs-sm); color: var(--text-light); }
.nav-drawer-info p { margin-bottom: 4px; }

body.nav-open { overflow: hidden; }

/* --- Hero --- */
.hero {
  position: relative;
  min-height: 100vh;
  min-height: 100svh;
  display: flex;
  align-items: center;
  background: var(--bg-dark);
  color: var(--text-on-dark);
  overflow: hidden;
  padding-top: var(--nav-h);
}
.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}
.hero-bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.hero-overlay {
  position: absolute;
  inset: 0;
  z-index: 1;
  background: linear-gradient(
    135deg,
    rgba(0, 34, 102, 0.92) 0%,
    rgba(1, 53, 128, 0.78) 50%,
    rgba(1, 53, 128, 0.6) 100%
  );
}
.hero-content {
  position: relative;
  z-index: 2;
  width: 100%;
  padding: var(--sp-xl) var(--page-pad);
}
.hero .overline {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  font-weight: 600;
  letter-spacing: 0.14em;
  color: var(--cyan);
  text-transform: uppercase;
  margin-bottom: var(--sp-sm);
}
.hero h1 {
  color: #fff;
  font-size: var(--fs-h1);
  font-weight: 800;
  margin-bottom: var(--sp-sm);
  line-height: var(--lh-tight);
}
.hero h1 em, .hero h1 strong { color: var(--cyan); font-style: normal; }
.hero .lead {
  font-size: var(--fs-md);
  color: var(--text-on-dark-80);
  line-height: var(--lh);
  max-width: 540px;
  margin-bottom: var(--sp-lg);
}
.hero-actions { display: flex; flex-wrap: wrap; gap: var(--sp-sm); }

/* 小型 Hero（内页） */
.hero-sm {
  position: relative;
  min-height: 380px;
  display: flex;
  align-items: center;
  background: var(--bg-dark);
  color: var(--text-on-dark);
  overflow: hidden;
  padding-top: var(--nav-h);
}
.hero-sm .hero-bg img { object-fit: cover; }
.hero-sm .hero-overlay {
  background: linear-gradient(
    135deg,
    rgba(0, 34, 102, 0.9) 0%,
    rgba(1, 53, 128, 0.75) 100%
  );
}
.hero-sm .hero-content { padding: var(--sp-xl) var(--page-pad); }
.hero-sm h1 { color: #fff; font-size: var(--fs-h2); margin-bottom: var(--sp-xs); }
.hero-sm .lead { font-size: var(--fs-base); margin-bottom: 0; }

/* --- Service Cards --- */
.card-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--sp-sm);
}
.svc-card {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  min-height: 200px;
  display: flex;
  align-items: flex-end;
  text-decoration: none;
  background: var(--navy);
  transition: transform var(--duration) var(--ease), box-shadow var(--duration) var(--ease);
}
.svc-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-lg); }
.svc-card img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s var(--ease);
}
.svc-card:hover img { transform: scale(1.06); }
.svc-card .card-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(to top, rgba(0, 34, 102, 0.92) 0%, rgba(1, 53, 128, 0.4) 55%, rgba(1, 53, 128, 0.1) 100%);
}
.svc-card .card-body {
  position: relative;
  z-index: 2;
  padding: var(--sp-md);
  color: #fff;
  width: 100%;
}
.svc-card .card-num {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  font-weight: 700;
  color: var(--cyan);
  letter-spacing: 0.08em;
  margin-bottom: 4px;
}
.svc-card h4 { color: #fff; font-size: var(--fs-md); margin-bottom: 4px; }
.svc-card p { color: var(--text-on-dark-60); font-size: var(--fs-xs); line-height: var(--lh-snug); margin: 0; }

/* --- Feature / Value Cards (白底) --- */
.feature-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--sp-sm);
}
.feature-card {
  background: var(--bg);
  padding: var(--sp-md);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: all var(--duration) var(--ease);
}
.feature-card:hover { border-color: var(--navy-light); box-shadow: var(--shadow-md); transform: translateY(-2px); }
.feature-card .f-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  background: var(--cyan-soft);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--sp-sm);
  color: var(--navy);
}
.feature-card .f-icon svg { width: 24px; height: 24px; }
.feature-card h4 { font-size: var(--fs-md); margin-bottom: var(--sp-xs); color: var(--text); }
.feature-card p { font-size: var(--fs-sm); color: var(--text-secondary); line-height: var(--lh); margin: 0; }

/* --- Difference / 对比卡片 --- */
.diff-grid { display: grid; grid-template-columns: 1fr; gap: var(--sp-sm); }
.diff-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: var(--sp-md);
  position: relative;
  overflow: hidden;
}
.diff-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: var(--cyan);
}
.diff-card .diff-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  font-weight: 600;
  color: var(--cyan-dark);
  letter-spacing: 0.08em;
  margin-bottom: var(--sp-xs);
}
.diff-card h4 { font-size: var(--fs-md); margin-bottom: var(--sp-xs); }
.diff-card .diff-vs {
  font-size: var(--fs-sm);
  color: var(--text-light);
  margin-top: var(--sp-xs);
  padding-top: var(--sp-xs);
  border-top: 1px dashed var(--border);
}
.diff-card .diff-vs strong { color: var(--text-secondary); }

/* --- Process / 建设路径 --- */
.process-timeline { display: flex; flex-direction: column; gap: 0; }
.process-step-item {
  display: flex;
  gap: var(--sp-md);
  padding-bottom: var(--sp-lg);
  position: relative;
}
.process-step-item:last-child { padding-bottom: 0; }
.process-step-item::before {
  content: '';
  position: absolute;
  left: 19px;
  top: 40px;
  bottom: 0;
  width: 2px;
  background: var(--border);
}
.process-step-item:last-child::before { display: none; }
.process-step-num {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--bg);
  border: 2px solid var(--navy);
  color: var(--navy);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: var(--fs-sm);
  font-weight: 700;
  flex-shrink: 0;
  position: relative;
  z-index: 1;
}
.process-step-body h4 { font-size: var(--fs-md); margin-bottom: 4px; }
.process-step-body p { font-size: var(--fs-sm); color: var(--text-secondary); margin: 0; }

/* --- Insight Cards (深色区) --- */
.insight-list { display: flex; flex-direction: column; gap: var(--sp-sm); }
.insight-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--sp-md);
  padding: var(--sp-md);
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--border-dark);
  border-radius: var(--radius);
  text-decoration: none;
  color: inherit;
  transition: all var(--duration) var(--ease);
}
.insight-item:hover { border-color: var(--cyan); background: rgba(0, 200, 224, 0.08); }
.insight-item .insight-content h4 { color: #fff; font-size: var(--fs-md); margin-bottom: 4px; transition: color var(--duration); }
.insight-item:hover .insight-content h4 { color: var(--cyan); }
.insight-item .insight-content p { color: var(--text-on-dark-60); font-size: var(--fs-sm); margin: 0; }
.insight-item .arrow { color: var(--cyan); font-size: var(--fs-lg); flex-shrink: 0; }

/* 洞察文章卡片（白底列表） */
.article-card {
  display: flex;
  flex-direction: column;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  text-decoration: none;
  transition: all var(--duration) var(--ease);
}
.article-card:hover { box-shadow: var(--shadow-md); transform: translateY(-3px); border-color: var(--navy-light); }
.article-card .ac-img { width: 100%; height: 200px; overflow: hidden; }
.article-card .ac-img img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.5s var(--ease); }
.article-card:hover .ac-img img { transform: scale(1.05); }
.article-card .ac-body { padding: var(--sp-md); flex: 1; display: flex; flex-direction: column; }
.article-card .ac-meta { font-family: var(--font-mono); font-size: var(--fs-xs); color: var(--cyan-dark); font-weight: 600; letter-spacing: 0.08em; margin-bottom: var(--sp-xs); }
.article-card .ac-body h4 { font-size: var(--fs-md); margin-bottom: var(--sp-xs); color: var(--text); }
.article-card .ac-body p { font-size: var(--fs-sm); color: var(--text-secondary); margin-bottom: var(--sp-sm); flex: 1; }
.article-card .ac-link { font-size: var(--fs-sm); color: var(--navy); font-weight: 600; }
.article-card:hover .ac-link { color: var(--cyan-dark); }

/* --- CTA Block --- */
.cta-block {
  position: relative;
  background: var(--bg-dark);
  color: var(--text-on-dark);
  overflow: hidden;
}
.cta-block .cta-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}
.cta-block .cta-bg img { width: 100%; height: 100%; object-fit: cover; }
.cta-block .cta-overlay {
  position: absolute;
  inset: 0;
  z-index: 1;
  background: linear-gradient(135deg, rgba(0, 34, 102, 0.94) 0%, rgba(1, 53, 128, 0.82) 100%);
}
.cta-content {
  position: relative;
  z-index: 2;
  text-align: center;
  padding: var(--sp-xl) var(--page-pad);
  max-width: 640px;
  margin: 0 auto;
}
.cta-content h2 { color: #fff; font-size: var(--fs-h2); margin-bottom: var(--sp-sm); }
.cta-content p { color: var(--text-on-dark-80); font-size: var(--fs-md); margin-bottom: var(--sp-lg); }

/* --- Value Tags --- */
.tag {
  display: inline-block;
  font-size: var(--fs-xs);
  padding: 3px 10px;
  border-radius: var(--radius-pill);
  background: var(--bg-gray);
  color: var(--text-secondary);
  font-weight: 500;
}
.tag-cyan { background: var(--cyan-soft); color: var(--cyan-dark); }

/* --- Stats --- */
.stats-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: var(--sp-md); }
.stat-item { text-align: center; }
.stat-num {
  font-family: var(--font-display);
  font-size: var(--fs-h1);
  font-weight: 800;
  color: var(--navy);
  line-height: 1;
}
.section-dark .stat-num { color: var(--cyan); }
.stat-label { font-size: var(--fs-sm); color: var(--text-secondary); margin-top: var(--sp-xs); }
.section-dark .stat-label { color: var(--text-on-dark-60); }

/* --- About Photo Split --- */
.split-section { display: flex; flex-direction: column; gap: var(--sp-md); }
.split-img { border-radius: var(--radius); overflow: hidden; height: 240px; }
.split-img img { width: 100%; height: 100%; object-fit: cover; }
.split-text h3 { margin-bottom: var(--sp-sm); }
.split-text p { color: var(--text-secondary); }

/* --- Timeline (关于页合作流程) --- */
.timeline { position: relative; padding-left: 28px; }
.timeline::before {
  content: '';
  position: absolute;
  left: 6px;
  top: 4px;
  bottom: 4px;
  width: 2px;
  background: var(--border);
}
.timeline-item { position: relative; margin-bottom: var(--sp-lg); }
.timeline-item:last-child { margin-bottom: 0; }
.timeline-item::before {
  content: '';
  position: absolute;
  left: -28px;
  top: 4px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--bg);
  border: 3px solid var(--navy);
}
.timeline-item h4 { font-size: var(--fs-md); margin-bottom: 4px; }
.timeline-item p { font-size: var(--fs-sm); color: var(--text-secondary); margin: 0; }

/* --- FAQ --- */
.faq-item {
  border-bottom: 1px solid var(--border);
}
.faq-q {
  width: 100%;
  text-align: left;
  background: none;
  border: none;
  padding: var(--sp-md) 0;
  font-size: var(--fs-md);
  font-weight: 600;
  color: var(--text);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--sp-sm);
  cursor: pointer;
}
.faq-q .faq-icon {
  flex-shrink: 0;
  width: 24px;
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--navy);
  transition: transform var(--duration) var(--ease);
  font-size: var(--fs-lg);
}
.faq-item.open .faq-q .faq-icon { transform: rotate(45deg); color: var(--cyan-dark); }
.faq-a {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--duration) var(--ease);
}
.faq-item.open .faq-a { max-height: 400px; }
.faq-a-inner { padding: 0 0 var(--sp-md); font-size: var(--fs-sm); color: var(--text-secondary); line-height: var(--lh); }

/* --- Article Page --- */
.article-header {
  position: relative;
  min-height: 320px;
  display: flex;
  align-items: flex-end;
  overflow: hidden;
  padding-top: var(--nav-h);
}
.article-header .article-bg { position: absolute; inset: 0; z-index: 0; }
.article-header .article-bg img { width: 100%; height: 100%; object-fit: cover; }
.article-header .article-overlay {
  position: absolute;
  inset: 0;
  z-index: 1;
  background: linear-gradient(to top, rgba(0, 34, 102, 0.94) 0%, rgba(1, 53, 128, 0.5) 70%, rgba(1, 53, 128, 0.3) 100%);
}
.article-hero-text { position: relative; z-index: 2; padding: var(--sp-lg) var(--page-pad); color: #fff; max-width: var(--page-max); margin: 0 auto; width: 100%; }
.article-meta {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  font-weight: 600;
  letter-spacing: 0.1em;
  color: var(--cyan);
  text-transform: uppercase;
  margin-bottom: var(--sp-sm);
}
.article-hero-text h1 { color: #fff; font-size: var(--fs-h2); }

.article-body {
  max-width: var(--read-max);
  margin: 0 auto;
  padding: var(--sp-lg) var(--page-pad) var(--sp-xl);
  background: var(--bg);
}
.article-body h2 { font-size: var(--fs-h3); margin-top: var(--sp-lg); margin-bottom: var(--sp-sm); }
.article-body h2:first-child { margin-top: 0; }
.article-body h3 { font-size: var(--fs-md); margin-top: var(--sp-md); margin-bottom: var(--sp-xs); }
.article-body p { line-height: var(--lh-loose); margin-bottom: var(--sp-md); color: var(--text); }
.article-body blockquote {
  margin: var(--sp-lg) 0;
  padding: var(--sp-md) var(--sp-lg);
  border-left: 3px solid var(--cyan);
  background: var(--bg-soft);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  line-height: var(--lh);
}
.article-body blockquote p { margin-bottom: 0; color: var(--text-secondary); }
.article-body ul, .article-body ol { margin-bottom: var(--sp-md); padding-left: 24px; line-height: var(--lh-loose); }
.article-body li { margin-bottom: var(--sp-xs); color: var(--text); }
.article-body table { width: 100%; border-collapse: collapse; margin-bottom: var(--sp-md); font-size: var(--fs-sm); }
.article-body th, .article-body td { padding: var(--sp-xs) var(--sp-sm); border: 1px solid var(--border); text-align: left; }
.article-body th { background: var(--bg-soft); font-weight: 600; color: var(--text); }
.article-body strong { font-weight: 600; color: var(--navy); }
.article-nav {
  max-width: var(--read-max);
  margin: 0 auto;
  padding: 0 var(--page-pad) var(--sp-xl);
  display: flex;
  justify-content: space-between;
  gap: var(--sp-md);
  flex-wrap: wrap;
}
.article-nav a { font-size: var(--fs-sm); color: var(--text-secondary); font-weight: 500; }
.article-nav a:hover { color: var(--navy); }

/* --- Contact --- */
.contact-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--sp-lg);
  text-align: center;
  max-width: 480px;
  margin: 0 auto;
}
.contact-card .c-icon {
  width: 64px;
  height: 64px;
  border-radius: 50%;
  background: var(--cyan-soft);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto var(--sp-md);
  color: var(--navy);
}
.contact-card .c-icon svg { width: 32px; height: 32px; }
.contact-card h3 { margin-bottom: var(--sp-xs); }
.contact-card p { color: var(--text-secondary); margin-bottom: var(--sp-lg); }

/* --- Breadcrumb --- */
.breadcrumb {
  padding: var(--sp-md) 0 0;
  font-size: var(--fs-xs);
  color: var(--text-light);
}
.breadcrumb a { color: var(--text-light); }
.breadcrumb a:hover { color: var(--navy); }
.breadcrumb .sep { margin: 0 8px; color: var(--border); }
.breadcrumb .current { color: var(--text-secondary); }

/* --- Footer --- */
.site-footer {
  background: var(--navy-dark);
  color: var(--text-on-dark-60);
  padding: var(--sp-xl) var(--page-pad) var(--sp-lg);
}
.footer-inner {
  max-width: var(--page-max);
  margin: 0 auto;
}
.footer-top {
  display: flex;
  flex-direction: column;
  gap: var(--sp-lg);
  padding-bottom: var(--sp-lg);
  border-bottom: 1px solid var(--border-dark);
}
.footer-brand-block .footer-brand {
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 800;
  color: #fff;
  letter-spacing: -0.02em;
  margin-bottom: var(--sp-xs);
}
.footer-brand-block .footer-tagline { font-size: var(--fs-sm); color: var(--text-on-dark-60); }
.footer-links-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: var(--sp-md); }
.footer-col h5 { color: #fff; font-size: var(--fs-sm); font-weight: 600; margin-bottom: var(--sp-sm); letter-spacing: 0.02em; }
.footer-col ul { display: flex; flex-direction: column; gap: var(--sp-xs); }
.footer-col a { font-size: var(--fs-sm); color: var(--text-on-dark-60); }
.footer-col a:hover { color: var(--cyan); }
.footer-bottom {
  padding-top: var(--sp-md);
  display: flex;
  flex-direction: column;
  gap: var(--sp-xs);
  font-size: var(--fs-xs);
  color: var(--text-on-dark-40);
}

/* --- Scroll Animation --- */
.fade-up {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s var(--ease-out), transform 0.6s var(--ease-out);
}
.fade-up.visible { opacity: 1; transform: translateY(0); }

/* --- Utilities --- */
.text-center { text-align: center; }
.mt-sm { margin-top: var(--sp-sm); }
.mt-md { margin-top: var(--sp-md); }
.mt-lg { margin-top: var(--sp-lg); }
.mb-sm { margin-bottom: var(--sp-sm); }
.mb-md { margin-bottom: var(--sp-md); }
.mb-lg { margin-bottom: var(--sp-lg); }
.hidden-mobile { display: none; }

/* ========================================
   Tablet ≥768px
   ======================================== */
@media (min-width: 768px) {
  :root {
    --page-pad: 32px;
    --fs-h1: 40px;
    --fs-h2: 32px;
    --fs-h3: 26px;
    --fs-display: 52px;
    --sp-xl: 80px;
  }
  .card-grid { grid-template-columns: repeat(3, 1fr); gap: var(--sp-md); }
  .svc-card { min-height: 240px; }
  .feature-grid { grid-template-columns: repeat(3, 1fr); }
  .diff-grid { grid-template-columns: repeat(3, 1fr); }
  .stats-grid { grid-template-columns: repeat(4, 1fr); }
  .nav-links { display: flex; }
  .nav-toggle { display: none; }
  .hero { min-height: 640px; }
  .hero h1 { font-size: var(--fs-display); }
  .hero-sm { min-height: 420px; }
  .hero-sm h1 { font-size: var(--fs-h1); }
  .split-section { flex-direction: row; align-items: center; }
  .split-img { flex: 1; height: 360px; }
  .split-text { flex: 1; }
  .footer-top { flex-direction: row; justify-content: space-between; align-items: flex-start; }
  .footer-links-grid { grid-template-columns: repeat(3, 1fr); gap: var(--sp-xl); }
  .footer-bottom { flex-direction: row; justify-content: space-between; align-items: center; }
  .article-card .ac-img { height: 240px; }
  .contact-card { padding: var(--sp-xl); }
  .hidden-mobile { display: initial; }
  .process-timeline { flex-direction: row; gap: var(--sp-xs); overflow-x: auto; padding-bottom: var(--sp-sm); }
  .process-step-item { flex-direction: column; flex: 1; min-width: 140px; padding-bottom: 0; gap: var(--sp-sm); }
  .process-step-item::before { display: none; }
  .process-step-item::after {
    content: '';
    position: absolute;
    top: 20px;
    left: 100%;
    width: var(--sp-xs);
    height: 2px;
    background: var(--border);
  }
  .process-step-item:last-child::after { display: none; }
  .process-step-body { text-align: center; }
  .process-step-body h4 { font-size: var(--fs-sm); }
  .process-step-body p { font-size: var(--fs-xs); }
}

/* ========================================
   Desktop ≥1024px
   ======================================== */
@media (min-width: 1024px) {
  :root {
    --page-pad: 48px;
    --fs-h1: 48px;
    --fs-h2: 36px;
    --fs-h3: 28px;
    --fs-display: 60px;
    --sp-xl: 96px;
  }
  .svc-card { min-height: 280px; }
  .article-card .ac-img { height: 280px; }
  .hero h1 { font-size: var(--fs-display); max-width: 720px; }
  .hero .lead { font-size: var(--fs-lg); }
  .article-header { min-height: 420px; }
  .article-hero-text h1 { font-size: var(--fs-h1); }
}

/* ========================================
   Large ≥1440px
   ======================================== */
@media (min-width: 1440px) {
  :root { --page-max: 1320px; }
}

/* --- Reduced Motion --- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
  .fade-up { opacity: 1; transform: none; }
  html { scroll-behavior: auto; }
}