/* ===========================================================
   上海胥然科技有限公司 · 官网样式
   设计语言：深蓝科技 + 暖金品牌色，简约大气
   响应式：PC ≥1024 / 平板 768–1023 / 手机 <768
   =========================================================== */

/* ---------- 1. 设计令牌 ---------- */
:root {
  /* 主色 */
  --c-primary: #0b3d91;        /* 品牌深蓝（取自 XURAN Logo） */
  --c-primary-dark: #082a66;
  --c-accent: #f5a623;         /* 暖金（手册封面城市光带） */
  --c-accent-light: #ffd166;

  /* 中性 */
  --c-bg: #ffffff;
  --c-bg-alt: #f5f7fb;
  --c-bg-dark: #061229;
  --c-text: #1a2233;
  --c-text-muted: #5a6478;
  --c-border: #e3e7ef;

  /* 字体 */
  --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --font-display: "Inter", "PingFang SC", "Microsoft YaHei", sans-serif;

  /* 间距 / 圆角 / 阴影 */
  --container-max: 1200px;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --shadow-sm: 0 2px 8px rgba(11, 61, 145, .08);
  --shadow-md: 0 8px 24px rgba(11, 61, 145, .12);
  --shadow-lg: 0 20px 48px rgba(11, 61, 145, .18);

  /* 过渡 */
  --t-fast: .18s ease;
  --t-med: .28s ease;
}

/* ---------- 2. 重置 ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  color: var(--c-text);
  background: var(--c-bg);
  -webkit-font-smoothing: antialiased;
}
img, svg { display: block; max-width: 100%; height: auto; }
a { color: var(--c-primary); text-decoration: none; transition: color var(--t-fast); }
a:hover { color: var(--c-accent); }
button { font-family: inherit; cursor: pointer; }

/* ---------- 3. 容器 / 工具类 ---------- */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 24px;
}
.section { padding: 96px 0; }
.section--alt { background: var(--c-bg-alt); }
.section--dark {
  background: linear-gradient(135deg, var(--c-bg-dark) 0%, var(--c-primary-dark) 100%);
  color: #fff;
}
.section-title {
  font-size: clamp(28px, 3.4vw, 40px);
  font-weight: 700;
  margin: 0 0 12px;
  letter-spacing: .5px;
}
.section-subtitle {
  color: var(--c-text-muted);
  margin: 0 0 56px;
  font-size: 16px;
}
.section--dark .section-subtitle { color: rgba(255,255,255,.72); }
.eyebrow {
  display: inline-block;
  font-size: 13px;
  letter-spacing: 2px;
  color: var(--c-accent);
  font-weight: 600;
  margin-bottom: 12px;
  text-transform: uppercase;
}
.section--dark .eyebrow { color: var(--c-accent-light); }

/* ---------- 4. 顶部导航 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: #fff;
  border-bottom: 1px solid var(--c-border);
}
.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}
.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
}
.nav-logo .site-logo-img { height: 38px; width: auto; display: block; }
.nav-logo .logo-mark { width: 36px; height: 36px; }
.nav-logo .logo-sub {
  font-size: 11px;
  color: var(--c-text-muted);
  letter-spacing: 2px;
  font-weight: 400;
  margin-top: 2px;
}
.nav-logo-stack { display: flex; flex-direction: column; line-height: 1.1; }

.nav-links {
  display: flex;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 0;
}
.nav-links a {
  display: inline-block;
  padding: 10px 16px;
  font-size: 15px;
  font-weight: 500;
  color: var(--c-text);
  border-radius: var(--radius-sm);
  transition: all var(--t-fast);
}
.nav-links a:hover,
.nav-links a.is-active {
  color: var(--c-primary);
  background: rgba(11, 61, 145, .06);
}

.nav-toggle {
  display: none;
  width: 40px;
  height: 40px;
  border: none;
  background: transparent;
  padding: 0;
}
.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  margin: 5px auto;
  background: var(--c-primary);
  transition: transform var(--t-fast), opacity var(--t-fast);
}
.nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---------- 5. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 26px;
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  transition: all var(--t-med);
  white-space: nowrap;
}
.btn-primary {
  background: var(--c-primary);
  color: #fff;
}
.btn-primary:hover {
  background: var(--c-primary-dark);
  color: #fff;
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}
.btn-accent {
  background: var(--c-accent);
  color: #fff;
}
.btn-accent:hover {
  background: #e09412;
  color: #fff;
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}
.btn-outline {
  border-color: rgba(255,255,255,.5);
  color: #fff;
}
.btn-outline:hover {
  background: rgba(255,255,255,.1);
  color: #fff;
}

/* ---------- 6. Hero ---------- */
.hero {
  position: relative;
  min-height: 88vh;
  display: flex;
  align-items: center;
  color: #fff;
  overflow: hidden;
  isolation: isolate;
}
.hero-bg {
  position: absolute;
  inset: 0;
  z-index: -2;
  background: url("../img/hero.png") center/cover no-repeat;
}
.hero-overlay {
  position: absolute;
  inset: 0;
  z-index: -1;
  background:
    linear-gradient(120deg, rgba(6, 18, 41, .85) 0%, rgba(8, 42, 102, .55) 50%, rgba(6, 18, 41, .35) 100%);
}
.hero-content { max-width: 760px; padding: 120px 0; }
.hero h1 {
  font-family: var(--font-display);
  font-size: clamp(36px, 5.5vw, 60px);
  font-weight: 800;
  line-height: 1.15;
  margin: 0 0 20px;
  letter-spacing: .5px;
}
.hero h1 .accent { color: var(--c-accent-light); }
.hero p.lead {
  font-size: clamp(16px, 1.6vw, 19px);
  line-height: 1.7;
  color: rgba(255,255,255,.88);
  margin: 0 0 36px;
  max-width: 620px;
}
.hero-actions { display: flex; gap: 16px; flex-wrap: wrap; }
.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  margin-top: 72px;
  padding-top: 32px;
  border-top: 1px solid rgba(255,255,255,.18);
}
.hero-stats .stat {
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.hero-stats .stat-num {
  font-family: var(--font-display);
  font-size: clamp(28px, 3vw, 40px);
  font-weight: 700;
  color: var(--c-accent-light);
  line-height: 1;
}
.hero-stats .stat-label {
  font-size: 13px;
  color: rgba(255,255,255,.7);
  letter-spacing: 1px;
}

/* ---------- 7. 卡片网格 ---------- */
.grid { display: grid; gap: 24px; }
.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-radius: var(--radius-lg);
  padding: 32px 28px;
  box-shadow: var(--shadow-sm);
  transition: transform var(--t-med), box-shadow var(--t-med);
  border: 1px solid var(--c-border);
}
.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}
.card-icon {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, var(--c-primary) 0%, #1a5fc9 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  margin-bottom: 20px;
}
.card h3 {
  font-size: 20px;
  font-weight: 700;
  margin: 0 0 12px;
  color: var(--c-primary);
}
.card p { margin: 0; color: var(--c-text-muted); font-size: 15px; }

/* 下载中心卡片 */
.download-card {
  background: #fff;
  border-radius: var(--radius-lg);
  padding: 36px 30px;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--c-border);
  display: flex;
  flex-direction: column;
  transition: transform var(--t-med), box-shadow var(--t-med);
}
.download-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}
.download-card__icon {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  margin-bottom: 20px;
}
.download-card__icon--web { background: linear-gradient(135deg, #5b86ff 0%, #3a6ff7 100%); }
.download-card__icon--app { background: linear-gradient(135deg, #ff9a5b 0%, #f25643 100%); }
.download-card h3 {
  font-size: 20px;
  font-weight: 700;
  margin: 0 0 12px;
  color: var(--c-primary);
}
.download-card p { margin: 0 0 20px; color: var(--c-text-muted); font-size: 15px; }
.download-card .btn { align-self: flex-start; }
.download-card__row {
  display: flex;
  align-items: center;
  gap: 20px;
  margin-top: auto;
  flex-wrap: wrap;
}
.download-card__qr {
  width: 112px;
  height: 112px;
  border-radius: var(--radius-md);
  border: 1px solid var(--c-border);
  object-fit: cover;
}
.download-card__ver {
  margin: 16px 0 0 !important;
  font-size: 14px !important;
  font-weight: 600;
  color: var(--c-primary) !important;
}
.download-card__tip {
  margin: 8px 0 0 !important;
  font-size: 13px !important;
  line-height: 1.6;
  color: var(--c-text-muted) !important;
}

/* 下载双板块：玥管家（Web）/ 玥助手（App） */
.download-panels { padding: 80px 0; }
.download-panels__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  align-items: stretch;
}
.dl-panel {
  background: #fff;
  border: 1px solid var(--c-border);
  border-radius: var(--radius-lg);
  padding: 36px 34px;
  display: flex;
  flex-direction: column;
  transition: transform var(--t-med), box-shadow var(--t-med), border-color var(--t-med);
}
.dl-panel__title {
  font-size: 22px;
  font-weight: 700;
  margin: 0 0 8px;
  color: var(--c-text);
}
.dl-panel__desc {
  font-size: 14px;
  color: var(--c-text-muted);
  margin: 0;
  line-height: 1.7;
}
/* 左：玥管家（整块可点跳转） */
.dl-panel--web {
  text-decoration: none;
  color: inherit;
  cursor: pointer;
}
.dl-panel--web:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--c-primary);
}
.dl-panel--web .dl-panel__icon {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, #5b86ff 0%, #3a6ff7 100%);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 18px;
}
.dl-panel__go {
  margin-top: auto;
  padding-top: 22px;
  font-weight: 600;
  font-size: 15px;
  color: var(--c-primary);
}
/* 右：玥助手（安卓 / iOS 方块） */
.dl-panel--app .dl-panel__head { margin-bottom: 20px; }
.dl-app-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
  margin-top: auto;
}
.dl-app {
  border: 1px solid var(--c-border);
  border-radius: var(--radius-md);
  padding: 22px 16px;
  text-align: center;
  text-decoration: none;
  color: inherit;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  transition: transform var(--t-med), box-shadow var(--t-med), border-color var(--t-med);
}
.dl-app:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
  border-color: var(--c-primary);
}
.dl-app__icon {
  width: 46px;
  height: 46px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
}
.dl-app__icon--android { background: linear-gradient(135deg, #3ddc84 0%, #0d9c4f 100%); }
.dl-app__icon--ios     { background: linear-gradient(135deg, #6e6e6e 0%, #2c2c2c 100%); }
.dl-app__name { font-size: 15px; font-weight: 700; color: var(--c-text); }
.dl-app__hint { font-size: 12px; color: var(--c-text-muted); }
.dl-app__ver  { font-size: 12px; font-weight: 600; color: var(--c-primary); letter-spacing: .5px; margin-top: -2px; }
.dl-app--disabled { opacity: .55; cursor: not-allowed; }
.dl-app--disabled:hover { transform: none; box-shadow: none; border-color: var(--c-border); }
@media (max-width: 767px) {
  .download-panels__grid { grid-template-columns: 1fr; }
}

/* 产品系列卡 */
.product-card {
  background: #fff;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--c-border);
  transition: all var(--t-med);
  display: flex;
  flex-direction: column;
}
.product-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
  border-color: transparent;
}
.product-card .img-wrap {
  background: var(--c-bg-alt);
  padding: 28px;
  aspect-ratio: 4/3;
  display: flex;
  align-items: center;
  justify-content: center;
}
.product-card .img-wrap img {
  max-height: 100%;
  width: auto;
  object-fit: contain;
}
.product-card .body { padding: 24px 28px 28px; flex: 1; display: flex; flex-direction: column; }
.product-card .tag {
  display: inline-block;
  font-size: 12px;
  color: var(--c-accent);
  font-weight: 600;
  letter-spacing: 1.5px;
  margin-bottom: 8px;
}
.product-card h3 {
  font-size: 22px;
  font-weight: 700;
  margin: 0 0 10px;
  color: var(--c-primary);
}
.product-card p { margin: 0 0 18px; color: var(--c-text-muted); flex: 1; }
.product-card .meta {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 18px;
}
.product-card .meta span {
  font-size: 12px;
  padding: 4px 10px;
  background: var(--c-bg-alt);
  border-radius: 100px;
  color: var(--c-text-muted);
}
.product-card .link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-weight: 600;
  font-size: 14px;
  color: var(--c-primary);
}
.product-card .link::after {
  content: "→";
  transition: transform var(--t-fast);
}
.product-card:hover .link::after { transform: translateX(4px); }

/* ---------- 8. 时间线 ---------- */
.timeline {
  position: relative;
  padding-left: 28px;
  border-left: 2px solid var(--c-border);
  margin: 0;
}
.timeline-item {
  position: relative;
  padding-bottom: 32px;
}
.timeline-item:last-child { padding-bottom: 0; }
.timeline-item::before {
  content: "";
  position: absolute;
  left: -36px;
  top: 6px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--c-primary);
  border: 3px solid #fff;
  box-shadow: 0 0 0 2px var(--c-primary);
}
.timeline-item .year {
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 700;
  color: var(--c-accent);
  letter-spacing: 1px;
  margin-bottom: 6px;
}
.timeline-item h4 {
  font-size: 18px;
  font-weight: 700;
  margin: 0 0 8px;
  color: var(--c-text);
}
.timeline-item p { margin: 0; color: var(--c-text-muted); font-size: 15px; }

/* ---------- 9. 客户 logo wall ---------- */
.logo-wall {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 16px;
}
.logo-wall .logo-cell {
  background: #fff;
  border: 1px solid var(--c-border);
  border-radius: var(--radius-md);
  padding: 28px 20px;
  text-align: center;
  font-weight: 600;
  color: var(--c-text);
  letter-spacing: .5px;
  transition: all var(--t-fast);
}
.logo-wall .logo-cell:hover {
  border-color: var(--c-primary);
  color: var(--c-primary);
  transform: translateY(-2px);
}

/* ---------- 10. 表单 ---------- */
.form { display: grid; gap: 20px; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.field { display: flex; flex-direction: column; gap: 6px; }
.field label {
  font-size: 14px;
  font-weight: 600;
  color: var(--c-text);
}
.field label .req { color: #d33; }
.field input, .field textarea, .field select {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid var(--c-border);
  border-radius: var(--radius-sm);
  font: inherit;
  background: #fff;
  color: var(--c-text);
  transition: border-color var(--t-fast), box-shadow var(--t-fast);
}
.field input:focus, .field textarea:focus, .field select:focus {
  outline: none;
  border-color: var(--c-primary);
  box-shadow: 0 0 0 3px rgba(11, 61, 145, .12);
}
.field textarea { min-height: 140px; resize: vertical; }
.field-error { font-size: 13px; color: #d33; min-height: 18px; }
.form-status {
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  font-size: 14px;
  display: none;
}
.form-status.is-show { display: block; }
.form-status.is-success { background: #e6f7ee; color: #16794e; border: 1px solid #b8e6c8; }
.form-status.is-error { background: #fde8e8; color: #b21f1f; border: 1px solid #f5b8b8; }

/* ---------- 11. 联系信息卡 ---------- */
.contact-card {
  background: #fff;
  border-radius: var(--radius-lg);
  padding: 28px;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--c-border);
  height: 100%;
}
.contact-card h3 {
  margin: 0 0 16px;
  font-size: 18px;
  color: var(--c-primary);
  display: flex;
  align-items: center;
  gap: 10px;
}
.contact-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.contact-list li { font-size: 15px; color: var(--c-text); }
.contact-list li strong { color: var(--c-text-muted); font-weight: 500; font-size: 13px; display: block; margin-bottom: 2px; }

/* ---------- 12. 页脚 ---------- */
.site-footer {
  background: #061229;
  color: rgba(255,255,255,.7);
  padding: 64px 0 28px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 48px;
}
.footer-col h5 {
  color: #fff;
  font-size: 15px;
  margin: 0 0 16px;
  font-weight: 600;
}
.footer-col ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.footer-col a { color: rgba(255,255,255,.65); font-size: 14px; }
.footer-col a:hover { color: var(--c-accent-light); }
.footer-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: #fff;
  font-weight: 700;
  font-size: 20px;
  margin-bottom: 16px;
}
.footer-brand .logo-mark { width: 36px; height: 36px; }
.footer-brand .site-logo-img,
.footer-brand .footer-logo-img { height: 38px; width: auto; display: block; }
.footer-desc { font-size: 14px; line-height: 1.7; max-width: 360px; }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,.1);
  padding-top: 24px;
  margin-top: 8px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: rgba(255,255,255,.5);
  text-align: center;
}
.footer-bottom-row { line-height: 1.8; }
.footer-bottom-licenses { display: flex; flex-wrap: wrap; justify-content: center; align-items: center; gap: 0; }
.footer-bottom-licenses a { color: inherit; text-decoration: none; transition: color .2s; }
.footer-bottom-licenses a:hover { color: #fff; }
.footer-badge-link { display: inline-flex; align-items: center; gap: 5px; }
.footer-badge { width: 16px; height: 18px; display: block; }
.footer-bottom .sep { margin: 0 10px; opacity: .4; }

/* ---------- 12.5 产品轮播 & 灯箱 ---------- */
.carousel { position: relative; padding: 0 24px; }
.carousel-viewport { overflow: hidden; }
.carousel-track {
  display: flex;
  gap: 20px;
  transition: transform .5s cubic-bezier(.22,.61,.36,1);
  will-change: transform;
}
.carousel-slide {
  flex: 0 0 auto;
  width: clamp(168px, 21vw, 232px);
  margin: 0;
}
.carousel-slide img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: contain;
  background: var(--c-bg-alt);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-md);
  transition: transform .3s var(--t-med), box-shadow .3s var(--t-med);
  cursor: zoom-in;
  -webkit-user-select: none;
  user-select: none;
}
.carousel-slide:hover img {
  transform: scale(1.04);
  box-shadow: var(--shadow-md);
}
.carousel-slide figcaption {
  margin-top: 10px;
  text-align: center;
  font-size: 14px;
  font-weight: 600;
  color: var(--c-text);
}
/* 浅灰 section 下卡片用白底，避免与 section 背景同色 */
.section--alt .carousel-slide img { background: var(--c-bg); }

.carousel-arrow {
  position: absolute;
  top: calc(50% - 18px);
  transform: translateY(-50%);
  width: 44px;
  height: 44px;
  border-radius: 50%;
  border: 1px solid var(--c-border);
  background: #fff;
  color: var(--c-primary);
  font-size: 26px;
  line-height: 1;
  cursor: pointer;
  z-index: 3;
  box-shadow: var(--shadow-sm);
  transition: background .2s, color .2s;
}
.carousel-arrow:hover { background: var(--c-primary); color: #fff; }
.carousel-arrow.prev { left: -6px; }
.carousel-arrow.next { right: -6px; }

.carousel-dots {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin-top: 22px;
  flex-wrap: wrap;
}
.carousel-dot {
  width: 9px;
  height: 9px;
  padding: 0;
  border: none;
  border-radius: 50%;
  background: var(--c-border);
  cursor: pointer;
  transition: all .25s;
}
.carousel-dot.is-active {
  width: 24px;
  border-radius: 5px;
  background: var(--c-primary);
}

/* 灯箱 */
.lightbox {
  position: fixed;
  inset: 0;
  z-index: 1000;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background: rgba(8, 18, 38, .92);
}
.lightbox[hidden] { display: none; }
.lightbox-img {
  max-width: 86vw;
  max-height: 74vh;
  object-fit: contain;
  border-radius: 8px;
  box-shadow: 0 20px 60px rgba(0,0,0,.5);
}
.lightbox-caption {
  margin-top: 16px;
  color: #fff;
  font-size: 16px;
  letter-spacing: 1px;
}
.lightbox-close,
.lightbox-arrow {
  position: absolute;
  border: none;
  border-radius: 50%;
  background: rgba(255,255,255,.14);
  color: #fff;
  cursor: pointer;
  transition: background .2s;
}
.lightbox-close { top: 24px; right: 28px; width: 46px; height: 46px; font-size: 28px; }
.lightbox-arrow { top: 50%; transform: translateY(-50%); width: 54px; height: 54px; font-size: 32px; }
.lightbox-arrow.prev { left: 28px; }
.lightbox-arrow.next { right: 28px; }
.lightbox-close:hover,
.lightbox-arrow:hover { background: rgba(255,255,255,.3); }

/* ---------- 13. 响应式 ---------- */
@media (max-width: 1023px) {
  .section { padding: 72px 0; }
  .grid-3, .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .hero-stats { grid-template-columns: repeat(2, 1fr); gap: 20px; }
  .hero-content { padding: 96px 0; }
}

@media (max-width: 767px) {
  .container { padding: 0 20px; }
  .section { padding: 56px 0; }
  .section-subtitle { margin-bottom: 40px; }
  .grid-3, .grid-4, .grid-2 { grid-template-columns: 1fr; }
  .form-row { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; gap: 32px; }
  .footer-bottom { flex-direction: column; text-align: center; }
  .hero-stats { grid-template-columns: repeat(2, 1fr); margin-top: 48px; }
  .hero-content { padding: 72px 0; }
  .hero-actions .btn { flex: 1; justify-content: center; }

  /* 移动端导航：折叠为抽屉 */
  .nav-toggle { display: block; }
  .nav-links {
    position: absolute;
    top: 72px;
    left: 0;
    right: 0;
    background: #fff;
    flex-direction: column;
    gap: 0;
    padding: 12px 0;
    border-bottom: 1px solid var(--c-border);
    transform: translateY(-12px);
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--t-fast), transform var(--t-fast);
  }
  .nav-links.is-open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }
  .nav-links li { width: 100%; }
  .nav-links a { display: block; padding: 14px 24px; border-radius: 0; }
}

/* ---------- 14. 焦点可访问性 ---------- */
:focus-visible {
  outline: 2px solid var(--c-accent);
  outline-offset: 2px;
}

/* ---------- 15. 滚动渐入 ---------- */
[data-fade] {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity .6s ease, transform .6s ease;
}
[data-fade].is-in {
  opacity: 1;
  transform: translateY(0);
}

/* 滚动后 header 加深阴影 */
.site-header.is-scrolled {
  box-shadow: var(--shadow-sm);
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: .01ms !important;
    transition-duration: .01ms !important;
    scroll-behavior: auto !important;
  }
  [data-fade] { opacity: 1; transform: none; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: .01ms !important;
    transition-duration: .01ms !important;
    scroll-behavior: auto !important;
  }
}