/* ==========================================================
   愈安伴 · 官网共享样式
   设计语言对齐参考站：蓝色主色 #2563eb + 紫色点缀 #9333ea
   ========================================================== */

:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --primary-light: #dbeafe;
  --accent: #9333ea;
  --accent-light: #f3e8ff;
  --teal: #0d9488;
  --teal-light: #ccfbf1;
  --ink: #1f2937;
  --body: #4b5563;
  --muted: #6b7280;
  --bg: #ffffff;
  --bg-soft: #f9fafb;
  --border: #e5e7eb;
  --footer-bg: #111827;
  --footer-text: #9ca3af;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
  --font: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
}

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

html { scroll-behavior: smooth; scroll-padding-top: 84px; }

body {
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.7;
  color: var(--body);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

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

h1, h2, h3, h4 { color: var(--ink); line-height: 1.3; }

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.section { padding: 96px 0; }
.section-soft { background: var(--bg-soft); }

.text-gradient {
  background: linear-gradient(90deg, var(--primary), var(--accent));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 32px;
  border-radius: var(--radius-sm);
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: all 0.3s ease;
  font-family: var(--font);
}
.btn-primary {
  background: var(--primary);
  color: #fff;
  box-shadow: 0 4px 14px rgba(37, 99, 235, 0.35);
}
.btn-primary:hover {
  background: var(--primary-dark);
  transform: scale(1.05);
  box-shadow: 0 6px 20px rgba(37, 99, 235, 0.45);
}
.btn-outline {
  background: transparent;
  color: var(--primary);
  border: 2px solid var(--primary);
}
.btn-outline:hover {
  background: var(--primary-light);
  transform: scale(1.05);
}
.btn-white {
  background: #fff;
  color: var(--primary);
}
.btn-white:hover { transform: scale(1.05); background: #f0f6ff; }

/* ---------- 导航 ---------- */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(8px);
  transition: box-shadow 0.3s ease;
}
.site-header.scrolled { box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1); }

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

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

.brand-logo {
  width: 40px; height: 40px;
  border-radius: 10px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  display: flex; align-items: center; justify-content: center;
  color: #fff; font-size: 20px;
  box-shadow: 0 4px 10px rgba(37, 99, 235, 0.3);
  flex-shrink: 0;
  overflow: hidden;
}

.brand-logo img {
  width: 100%; height: 100%;
  object-fit: cover;
}

/* 首页顶部 / 底部横版 logo 独立样式（避免全局 img max-width 规则干扰） */
.site-header .brand-logo-img {
  height: 30px;
  width: auto;
  max-width: none;
  object-fit: contain;
  display: block;
}

.site-footer .brand-logo-img {
  height: 60px;
  width: auto;
  max-width: none;
  object-fit: contain;
  display: block;
}

.brand-text { display: flex; flex-direction: column; line-height: 1.2; }
.brand-name { font-size: 18px; font-weight: 800; color: var(--ink); letter-spacing: 0.5px; }
.brand-sub { font-size: 11px; color: var(--muted); letter-spacing: 1px; }

.nav-links { display: flex; align-items: center; gap: 4px; }
.nav-links a {
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  font-size: 15px;
  color: var(--body);
  transition: all 0.2s ease;
}
.nav-links a:hover { color: var(--primary); background: var(--primary-light); }
.nav-links a.active { color: var(--primary); font-weight: 600; background: var(--primary-light); }

.nav-qr {
  margin-left: 12px;
  width: 42px; height: 42px;
  border-radius: var(--radius-sm);
  border: 2px solid var(--primary);
  color: var(--primary);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  flex-shrink: 0;
  transition: all 0.3s ease;
}
.nav-qr:hover {
  background: var(--primary-light);
  transform: scale(1.05);
}

.nav-cta { margin-left: 12px; padding: 10px 24px; font-size: 15px; }

.nav-toggle {
  display: none;
  background: none; border: none;
  font-size: 24px; color: var(--ink);
  cursor: pointer; padding: 8px;
}

/* ---------- Hero ---------- */
.hero {
  padding: 160px 0 96px;
  background: linear-gradient(135deg, #eff6ff 0%, #e0e7ff 100%);
  position: relative;
  overflow: hidden;
}
.hero::before, .hero::after {
  content: "";
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.5;
  pointer-events: none;
}
.hero::before {
  width: 480px; height: 480px;
  background: #bfdbfe;
  top: -120px; right: -80px;
}
.hero::after {
  width: 360px; height: 360px;
  background: #e9d5ff;
  bottom: -100px; left: -60px;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
  position: relative;
  z-index: 1;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  border-radius: 999px;
  background: #fff;
  border: 1px solid var(--primary-light);
  color: var(--primary);
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 24px;
  box-shadow: 0 2px 8px rgba(37, 99, 235, 0.08);
}

.hero h1 {
  font-size: 60px;
  font-weight: 800;
  letter-spacing: 1px;
  margin-bottom: 24px;
}

.hero-sub {
  font-size: 20px;
  color: var(--body);
  margin-bottom: 40px;
  max-width: 560px;
}

.hero-actions { display: flex; gap: 16px; flex-wrap: wrap; }

.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  margin-top: 56px;
  position: relative;
  z-index: 1;
}
.stat-item {
  background: rgba(255, 255, 255, 0.75);
  backdrop-filter: blur(6px);
  border: 1px solid rgba(255, 255, 255, 0.9);
  border-radius: var(--radius);
  padding: 20px;
  text-align: center;
}
.stat-num {
  font-size: 32px;
  font-weight: 800;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.stat-label { font-size: 14px; color: var(--muted); margin-top: 4px; }

.hero-visual {
  position: relative;
  border-radius: 16px;
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  border: 4px solid #fff;
}

/* ---------- 章节标题 ---------- */
.section-head {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 64px;
}
.section-eyebrow {
  display: inline-block;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 2px;
  color: var(--primary);
  text-transform: uppercase;
  margin-bottom: 12px;
}
.section-head h2 { font-size: 36px; font-weight: 700; margin-bottom: 16px; }
.section-head p { font-size: 18px; color: var(--muted); }

/* ---------- 卡片网格 ---------- */
.grid { display: grid; gap: 32px; }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

.card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  box-shadow: var(--shadow);
  transition: all 0.3s ease;
}
.card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-lg);
  border-color: var(--primary-light);
}

.card-icon {
  width: 56px; height: 56px;
  border-radius: 14px;
  display: flex; align-items: center; justify-content: center;
  font-size: 24px;
  margin-bottom: 20px;
}
.icon-blue { background: var(--primary-light); color: var(--primary); }
.icon-teal { background: var(--teal-light); color: var(--teal); }
.icon-purple { background: var(--accent-light); color: var(--accent); }

.card h3 { font-size: 20px; font-weight: 700; margin-bottom: 12px; }
.card p { font-size: 15px; color: var(--body); }
.card-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-top: 16px;
  color: var(--primary);
  font-weight: 600;
  font-size: 15px;
  transition: gap 0.2s ease;
}
.card-link:hover { gap: 10px; }

/* ---------- 全病程时间线 ---------- */
.timeline {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  position: relative;
}
.timeline::before {
  content: "";
  position: absolute;
  top: 40px; left: 8%; right: 8%;
  height: 3px;
  background: linear-gradient(90deg, var(--primary-light), var(--primary), var(--accent-light));
  z-index: 0;
}
.timeline-step { position: relative; text-align: center; z-index: 1; }
.timeline-dot {
  width: 80px; height: 80px;
  margin: 0 auto 20px;
  border-radius: 50%;
  background: #fff;
  border: 3px solid var(--primary);
  display: flex; align-items: center; justify-content: center;
  font-size: 30px;
  color: var(--primary);
  box-shadow: 0 4px 14px rgba(37, 99, 235, 0.2);
}
.timeline-step h3 { font-size: 18px; margin-bottom: 8px; }
.timeline-step p { font-size: 14px; color: var(--muted); padding: 0 8px; }

/* ---------- 特色区块（图文） ---------- */
.feature-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}
.feature-row + .feature-row { margin-top: 96px; }
.feature-row.reverse .feature-text { order: 2; }

.feature-text h2 { font-size: 36px; font-weight: 700; margin-bottom: 16px; }
.feature-text > p { font-size: 17px; margin-bottom: 24px; }

.check-list { display: grid; gap: 14px; margin-bottom: 32px; }
.check-list li {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  font-size: 15px;
}
.check-list i {
  color: var(--teal);
  font-size: 18px;
  margin-top: 4px;
  flex-shrink: 0;
}
.check-list strong { color: var(--ink); display: block; font-size: 15px; }
.check-list span { font-size: 14px; color: var(--muted); }

.feature-media {
  border-radius: 16px;
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--border);
}
.feature-media img { width: 100%; height: auto; }

/* ---------- AI 对话 Mock ---------- */
.chat-mock {
  background: #fff;
  border-radius: 16px;
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--border);
  overflow: hidden;
  max-width: 420px;
}
.chat-head {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 16px 20px;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  color: #fff;
  font-weight: 600;
}
.chat-body { padding: 20px; display: grid; gap: 14px; background: var(--bg-soft); }
.chat-msg {
  max-width: 85%;
  padding: 12px 16px;
  border-radius: 14px;
  font-size: 14px;
  line-height: 1.6;
}
.chat-msg.user {
  justify-self: end;
  background: var(--primary);
  color: #fff;
  border-bottom-right-radius: 4px;
}
.chat-msg.ai {
  justify-self: start;
  background: #fff;
  color: var(--body);
  border: 1px solid var(--border);
  border-bottom-left-radius: 4px;
}
.chat-msg .tag {
  display: inline-block;
  font-size: 12px;
  font-weight: 700;
  color: var(--teal);
  margin-bottom: 4px;
}
.typing { display: inline-flex; gap: 4px; padding: 4px 0; }
.typing i {
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--primary);
  animation: blink 1.2s infinite;
}
.typing i:nth-child(2) { animation-delay: 0.2s; }
.typing i:nth-child(3) { animation-delay: 0.4s; }
@keyframes blink {
  0%, 60%, 100% { opacity: 0.25; }
  30% { opacity: 1; }
}

/* ---------- 多终端 ---------- */
.terminal-card { text-align: center; }
.terminal-preview {
  height: 220px;
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  font-size: 64px;
  overflow: hidden;
  position: relative;
}
.preview-app { background: linear-gradient(160deg, #dbeafe, #e0e7ff); color: var(--primary); }
.preview-doc { background: linear-gradient(160deg, #ccfbf1, #d1fae5); color: var(--teal); }
.preview-web { background: linear-gradient(160deg, #f3e8ff, #ede9fe); color: var(--accent); }
.preview-cs  { background: linear-gradient(160deg, #fef3c7, #fde68a); color: #d97706; }

.phone-frame {
  width: 96px; height: 180px;
  border: 5px solid var(--ink);
  border-radius: 18px;
  background: #fff;
  position: relative;
  box-shadow: var(--shadow);
}
.phone-frame::before {
  content: "";
  position: absolute;
  top: 6px; left: 50%; transform: translateX(-50%);
  width: 32px; height: 4px;
  border-radius: 2px;
  background: #d1d5db;
}
.phone-screen {
  position: absolute;
  inset: 12px 6px 6px;
  border-radius: 10px;
  background: linear-gradient(180deg, #eff6ff, #fff);
  display: flex;
  flex-direction: column;
  gap: 5px;
  padding: 8px;
}
.phone-screen i {
  display: block;
  height: 8px;
  border-radius: 4px;
  background: var(--primary-light);
}
.phone-screen i:first-child { background: var(--primary); width: 70%; }
.phone-screen i:nth-child(2) { width: 90%; }
.phone-screen i:nth-child(3) { width: 50%; background: var(--teal-light); }
.phone-screen i:nth-child(4) { width: 80%; }

/* ---------- 架构图 ---------- */
.arch-stack { display: grid; gap: 16px; }
.arch-layer {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 28px;
  display: grid;
  grid-template-columns: 180px 1fr;
  gap: 24px;
  align-items: center;
  transition: all 0.3s ease;
}
.arch-layer:hover { border-color: var(--primary); box-shadow: var(--shadow); }
.arch-layer-title {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  color: var(--ink);
}
.arch-layer-title i { color: var(--primary); font-size: 20px; }
.arch-nodes { display: flex; flex-wrap: wrap; gap: 10px; }
.arch-node {
  padding: 8px 16px;
  border-radius: 999px;
  font-size: 14px;
  font-weight: 600;
  background: var(--bg-soft);
  border: 1px solid var(--border);
  color: var(--body);
  transition: all 0.2s ease;
}
.arch-node:hover { border-color: var(--primary); color: var(--primary); background: var(--primary-light); }
.arch-node small { display: block; font-size: 12px; font-weight: 400; color: var(--muted); }

.arch-arrow {
  text-align: center;
  color: var(--primary);
  font-size: 20px;
  line-height: 1;
}

/* ---------- 对比卡片（双模型） ---------- */
.compare-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 32px; }
.compare-card {
  border-radius: var(--radius);
  padding: 32px;
  border: 2px solid var(--border);
  background: #fff;
  transition: all 0.3s ease;
}
.compare-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); }
.compare-card.private { border-color: var(--teal); }
.compare-card.cloud { border-color: var(--primary); }
.compare-card h3 { display: flex; align-items: center; gap: 10px; font-size: 20px; margin-bottom: 8px; }
.compare-card .compare-label {
  display: inline-block;
  font-size: 12px;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: 999px;
  margin-bottom: 16px;
}
.compare-card.private .compare-label { background: var(--teal-light); color: var(--teal); }
.compare-card.cloud .compare-label { background: var(--primary-light); color: var(--primary); }

/* ---------- 数据看板 ---------- */
.dashboard-mock {
  background: #fff;
  border-radius: 16px;
  border: 1px solid var(--border);
  box-shadow: var(--shadow-lg);
  padding: 24px;
}
.dashboard-bar-chart {
  display: flex;
  align-items: flex-end;
  gap: 14px;
  height: 160px;
  padding-top: 12px;
}
.dashboard-bar-chart div {
  flex: 1;
  border-radius: 6px 6px 0 0;
  background: linear-gradient(180deg, var(--primary), #93c5fd);
  position: relative;
}
.dashboard-bar-chart div span {
  position: absolute;
  bottom: -24px; left: 50%; transform: translateX(-50%);
  font-size: 12px;
  color: var(--muted);
  white-space: nowrap;
}

/* ---------- 页面头部（子页面） ---------- */
.page-hero {
  padding: 150px 0 80px;
  background: linear-gradient(135deg, #eff6ff 0%, #e0e7ff 100%);
  text-align: center;
  position: relative;
  overflow: hidden;
}
.page-hero::before {
  content: "";
  position: absolute;
  width: 480px; height: 480px;
  border-radius: 50%;
  background: #bfdbfe;
  filter: blur(90px);
  opacity: 0.4;
  top: -160px; right: -100px;
}
.page-hero h1 { font-size: 48px; font-weight: 800; margin-bottom: 16px; position: relative; }
.page-hero p { font-size: 19px; max-width: 680px; margin: 0 auto; position: relative; }

.breadcrumb {
  display: flex;
  justify-content: center;
  gap: 8px;
  font-size: 14px;
  color: var(--muted);
  margin-bottom: 20px;
  position: relative;
}
.breadcrumb a { color: var(--primary); }
.breadcrumb a:hover { text-decoration: underline; }

/* ---------- CTA 横幅 ---------- */
.cta-banner {
  background: linear-gradient(135deg, var(--primary), var(--accent));
  border-radius: 20px;
  padding: 64px 48px;
  text-align: center;
  color: #fff;
  position: relative;
  overflow: hidden;
}
.cta-banner::before, .cta-banner::after {
  content: "";
  position: absolute;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.12);
}
.cta-banner::before { width: 300px; height: 300px; top: -120px; left: -80px; }
.cta-banner::after { width: 220px; height: 220px; bottom: -90px; right: -50px; }
.cta-banner h2 { color: #fff; font-size: 36px; margin-bottom: 16px; position: relative; }
.cta-banner p { font-size: 18px; opacity: 0.92; margin-bottom: 32px; position: relative; }
.cta-banner .btn { position: relative; }

/* ---------- 联系表单 ---------- */
.contact-wrap {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 48px;
  align-items: start;
}
.contact-info-item {
  display: flex;
  gap: 16px;
  align-items: flex-start;
  margin-bottom: 28px;
}
.contact-info-item i {
  width: 48px; height: 48px;
  border-radius: 12px;
  background: var(--primary-light);
  color: var(--primary);
  display: flex; align-items: center; justify-content: center;
  font-size: 20px;
  flex-shrink: 0;
}
.contact-info-item h4 { font-size: 16px; margin-bottom: 2px; }
.contact-info-item p { font-size: 15px; color: var(--muted); }

/* 强制单行显示（联系方式等短文本防换行） */
.text-nowrap { white-space: nowrap !important; }
/* 联系信息项：图标 + 文本布局下允许文本块按需扩展，不被压缩换行 */
.contact-info-item > div { flex: 1; min-width: 0; }
.contact-info-item > div .text-nowrap { display: block; overflow: visible; }

.contact-form-panel {
  background: var(--bg-soft);
  border-radius: 16px;
  padding: 40px;
  border: 1px solid var(--border);
}
.form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.form-group { display: flex; flex-direction: column; gap: 6px; }
.form-group.full { grid-column: 1 / -1; }
.form-group label { font-size: 14px; font-weight: 600; color: var(--ink); }
.form-group input,
.form-group textarea,
.form-group select {
  padding: 12px 16px;
  border: 1px solid #d1d5db;
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-family: var(--font);
  transition: all 0.2s ease;
  background: #fff;
  color: var(--ink);
}
.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.25);
}
.form-group textarea { resize: vertical; min-height: 120px; }

/* ---------- 页脚 ---------- */
.site-footer {
  background: var(--footer-bg);
  color: var(--footer-text);
  padding: 72px 0 0;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1.2fr;
  gap: 48px;
  padding-bottom: 56px;
}
.footer-brand .brand-name { color: #fff; }
.footer-brand p { font-size: 14px; margin-top: 16px; line-height: 1.8; }
.site-footer h4 {
  color: #fff;
  font-size: 16px;
  margin-bottom: 20px;
}
.footer-links { display: grid; gap: 12px; }
.footer-links a { font-size: 14px; transition: color 0.2s ease; }
.footer-links a:hover { color: #fff; }
.footer-contact { display: grid; gap: 12px; font-size: 14px; }
.footer-contact li { display: flex; gap: 10px; align-items: flex-start; }
.footer-contact i { color: #60a5fa; margin-top: 4px; }
.footer-bottom {
  border-top: 1px solid #1f2937;
  padding: 24px 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 13px;
  flex-wrap: wrap;
  gap: 12px;
}
.footer-bottom-links { display: flex; gap: 24px; }
.footer-bottom-links a:hover { color: #fff; }

/* ---------- App 下载页 ---------- */
.download-poster {
  max-width: 640px;
  margin: 0 auto;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 24px;
  box-shadow: var(--shadow-lg);
}
.download-poster img {
  width: 100%;
  border-radius: 12px;
}
.download-tip {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  margin: 0 auto 32px;
  max-width: 640px;
  padding: 14px 24px;
  border-radius: 999px;
  background: var(--primary-light);
  color: var(--primary-dark);
  font-weight: 600;
}
.download-steps { max-width: 860px; margin: 64px auto 0; }
.step-item {
  display: flex;
  gap: 20px;
  align-items: flex-start;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow);
  transition: all 0.3s ease;
}
.step-item:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); border-color: var(--primary-light); }
.step-num {
  width: 44px; height: 44px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: #fff;
  font-weight: 800;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}
.step-item h4 { font-size: 17px; margin-bottom: 4px; }
.step-item p { font-size: 14px; color: var(--muted); }

/* ---------- 滚动显现动画 ---------- */
.reveal {
  opacity: 0;
  transform: translateY(32px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.reveal.visible { opacity: 1; transform: translateY(0); }
.reveal-delay-1 { transition-delay: 0.12s; }
.reveal-delay-2 { transition-delay: 0.24s; }
.reveal-delay-3 { transition-delay: 0.36s; }

/* ---------- 响应式 ---------- */
@media (max-width: 992px) {
  .section { padding: 72px 0; }
  .hero { padding: 130px 0 72px; }
  .hero h1 { font-size: 42px; }
  .hero-grid { grid-template-columns: 1fr; gap: 40px; }
  .hero-sub { font-size: 17px; }
  .section-head h2 { font-size: 30px; }
  .grid-3, .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .feature-row { grid-template-columns: 1fr; gap: 40px; }
  .feature-row + .feature-row { margin-top: 64px; }
  .feature-row.reverse .feature-text { order: 0; }
  .timeline { grid-template-columns: repeat(2, 1fr); gap: 40px; }
  .timeline::before { display: none; }
  .contact-wrap { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: repeat(2, 1fr); }
  .page-hero h1 { font-size: 34px; }
  .compare-grid { grid-template-columns: 1fr; }
  .arch-layer { grid-template-columns: 1fr; gap: 12px; }
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 72px; left: 0; right: 0;
    background: #fff;
    flex-direction: column;
    align-items: stretch;
    padding: 12px 24px 20px;
    gap: 2px;
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    border-top: 1px solid var(--border);
  }
  .nav-links.open { display: flex; }
  .nav-toggle { display: block; }
  .nav-cta { display: none; }

  .hero h1 { font-size: 34px; }
  .hero-stats { grid-template-columns: repeat(2, 1fr); }
  .grid-3, .grid-4, .grid-2 { grid-template-columns: 1fr; }
  .form-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; gap: 36px; }
  .contact-form-panel { padding: 28px; }
  .cta-banner { padding: 48px 24px; }
  .cta-banner h2 { font-size: 26px; }
  .timeline { grid-template-columns: 1fr; }
  .feature-text h2 { font-size: 28px; }
}