/* =========================================================================
   HelloWorld 官网 · 全站通用样式表
   文件：static/css/style.css
   说明：包含设计变量、基础布局、头部导航、首页模块、下载页、FAQ、
        关于我们、表单组件、页脚以及通用工具类与响应式规则。
   ========================================================================= */

/* ----------------------------- 1. 设计变量 ----------------------------- */
:root {
  /* 品牌色 */
  --primary: #165dff;
  --primary-dark: #0b3fb5;
  --primary-light: #e8f0ff;
  --accent: #00c2a8;
  --accent-light: #e4fbf7;
  --warn: #ff7d00;

  /* 中性色 */
  --text: #1d2129;
  --text-2: #4e5969;
  --text-3: #86909c;
  --border: #e5e8ef;
  --bg: #ffffff;
  --bg-soft: #f5f8ff;
  --bg-dark: #0a1b3d;

  /* 渐变 */
  --grad-primary: linear-gradient(135deg, #165dff 0%, #00a3ff 100%);
  --grad-deep: linear-gradient(150deg, #071630 0%, #0f3a86 55%, #165dff 100%);
  --grad-accent: linear-gradient(135deg, #00c2a8 0%, #165dff 100%);
  --grad-soft: linear-gradient(180deg, #f5f8ff 0%, #ffffff 100%);

  /* 阴影 */
  --shadow-sm: 0 2px 8px rgba(22, 93, 255, 0.06);
  --shadow: 0 12px 32px rgba(15, 46, 106, 0.10);
  --shadow-lg: 0 24px 60px rgba(15, 46, 106, 0.16);
  --shadow-primary: 0 16px 36px rgba(22, 93, 255, 0.28);

  /* 圆角与布局 */
  --radius-sm: 10px;
  --radius: 16px;
  --radius-lg: 24px;
  --radius-pill: 999px;
  --container: 1200px;
  --header-h: 72px;

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

/* ----------------------------- 2. 基础重置 ----------------------------- */
*,
*::before,
*::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 16px);
}

body {
  margin: 0;
  font-family: "PingFang SC", "HarmonyOS Sans SC", "Microsoft YaHei",
    "Helvetica Neue", Helvetica, Arial, "Noto Sans SC", sans-serif;
  font-size: 16px;
  line-height: 1.75;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
  margin: 0 0 0.5em;
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.01em;
  color: var(--text);
}

p { margin: 0 0 1em; }

a {
  color: var(--primary);
  text-decoration: none;
  transition: color 0.25s var(--ease);
}
a:hover { color: var(--primary-dark); }

img { max-width: 100%; height: auto; display: block; }

ul, ol { margin: 0 0 1em; padding-left: 1.2em; }

button { font-family: inherit; }

::selection { background: var(--primary); color: #fff; }

/* 无障碍：跳转到主内容 */
.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  z-index: 999;
  padding: 10px 18px;
  background: var(--primary);
  color: #fff;
  border-radius: 0 0 var(--radius-sm) 0;
}
.skip-link:focus { left: 0; color: #fff; }

/* ----------------------------- 3. 布局工具 ----------------------------- */
.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}

.section { padding: 88px 0; position: relative; }
.section--soft { background: var(--bg-soft); }
.section--grad { background: var(--grad-soft); }
.section--dark { background: var(--grad-deep); color: #fff; }
.section--dark h2,
.section--dark h3,
.section--dark h4 { color: #fff; }
.section--dark p { color: rgba(255, 255, 255, 0.78); }
.section--tight { padding: 56px 0; }

.section-head {
  max-width: 760px;
  margin: 0 auto 56px;
  text-align: center;
}
.section-head--left { margin-left: 0; text-align: left; }

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 16px;
  padding: 6px 16px;
  font-size: 14px;
  font-weight: 600;
  color: var(--primary);
  background: var(--primary-light);
  border-radius: var(--radius-pill);
}
.section--dark .section-tag {
  color: #fff;
  background: rgba(255, 255, 255, 0.14);
}

.section-title {
  font-size: clamp(26px, 3.4vw, 40px);
  margin-bottom: 16px;
}
.section-desc {
  font-size: 17px;
  color: var(--text-2);
  margin: 0;
}
.section--dark .section-desc { color: rgba(255, 255, 255, 0.72); }

.grid { display: grid; gap: 24px; }
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

.text-center { text-align: center; }
.mt-0 { margin-top: 0; }
.mb-0 { margin-bottom: 0; }

/* ----------------------------- 4. 按钮 ----------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 26px;
  font-size: 15px;
  font-weight: 600;
  line-height: 1.2;
  border: 1px solid transparent;
  border-radius: var(--radius-pill);
  cursor: pointer;
  white-space: nowrap;
  transition: transform 0.25s var(--ease), box-shadow 0.25s var(--ease),
    background 0.25s var(--ease), color 0.25s var(--ease), border-color 0.25s var(--ease);
}
.btn:hover { transform: translateY(-2px); }
.btn:active { transform: translateY(0); }

.btn--primary {
  color: #fff;
  background: var(--grad-primary);
  box-shadow: var(--shadow-primary);
}
.btn--primary:hover { color: #fff; box-shadow: 0 20px 44px rgba(22, 93, 255, 0.36); }

.btn--ghost {
  color: var(--text);
  background: #fff;
  border-color: var(--border);
  box-shadow: var(--shadow-sm);
}
.btn--ghost:hover { color: var(--primary); border-color: var(--primary); }

.btn--light {
  color: var(--primary-dark);
  background: #fff;
  box-shadow: var(--shadow);
}
.btn--light:hover { color: var(--primary); }

.btn--outline-light {
  color: #fff;
  background: rgba(255, 255, 255, 0.08);
  border-color: rgba(255, 255, 255, 0.4);
}
.btn--outline-light:hover { color: #fff; background: rgba(255, 255, 255, 0.18); }

.btn--lg { padding: 15px 34px; font-size: 16px; }
.btn--block { width: 100%; }
.btn--sm { padding: 9px 18px; font-size: 14px; }

.btn-row {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
}
.btn-row--center { justify-content: center; }

/* ----------------------------- 5. 头部导航 ----------------------------- */
.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 100;
  height: var(--header-h);
  display: flex;
  align-items: center;
  background: rgba(255, 255, 255, 0.82);
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid transparent;
  transition: background 0.3s var(--ease), border-color 0.3s var(--ease),
    box-shadow 0.3s var(--ease);
}
.site-header.is-scrolled {
  background: rgba(255, 255, 255, 0.96);
  border-bottom-color: var(--border);
  box-shadow: 0 6px 24px rgba(15, 46, 106, 0.06);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  width: 100%;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 20px;
  font-weight: 800;
  color: var(--text);
  letter-spacing: -0.02em;
}
.brand:hover { color: var(--text); }
.brand__logo { width: 34px; height: 34px; border-radius: 10px; }
.brand__text small {
  display: block;
  font-size: 11px;
  font-weight: 500;
  color: var(--text-3);
  letter-spacing: 0.06em;
  line-height: 1.2;
}

.nav { display: flex; align-items: center; }
.nav__list {
  display: flex;
  align-items: center;
  gap: 4px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.nav__link {
  position: relative;
  display: block;
  padding: 8px 16px;
  font-size: 15px;
  font-weight: 500;
  color: var(--text-2);
  border-radius: var(--radius-pill);
  transition: color 0.25s var(--ease), background 0.25s var(--ease);
}
.nav__link:hover { color: var(--primary); background: var(--primary-light); }
.nav__link.is-active { color: var(--primary); font-weight: 600; }
.nav__link.is-active::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: 2px;
  width: 18px;
  height: 3px;
  transform: translateX(-50%);
  background: var(--grad-primary);
  border-radius: 3px;
}

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

.nav-toggle {
  display: none;
  width: 42px;
  height: 42px;
  padding: 0;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 12px;
  cursor: pointer;
}
.nav-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  margin: 4px auto;
  background: var(--text);
  border-radius: 2px;
  transition: transform 0.3s var(--ease), opacity 0.3s var(--ease);
}
.nav-toggle.is-open span:nth-child(1) { transform: translateY(6px) rotate(45deg); }
.nav-toggle.is-open span:nth-child(2) { opacity: 0; }
.nav-toggle.is-open span:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

/* ----------------------------- 6. 首屏 Hero ----------------------------- */
.hero {
  position: relative;
  padding: calc(var(--header-h) + 84px) 0 96px;
  background: var(--grad-deep);
  color: #fff;
  overflow: hidden;
}
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    radial-gradient(circle at 12% 22%, rgba(0, 194, 168, 0.28), transparent 42%),
    radial-gradient(circle at 88% 12%, rgba(22, 93, 255, 0.55), transparent 46%),
    linear-gradient(rgba(255, 255, 255, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.05) 1px, transparent 1px);
  background-size: auto, auto, 46px 46px, 46px 46px;
  pointer-events: none;
}
.hero > .container { position: relative; z-index: 1; }

.hero__inner {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 56px;
  align-items: center;
}
.hero__eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 22px;
  padding: 7px 16px;
  font-size: 14px;
  font-weight: 600;
  color: #d4e4ff;
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: var(--radius-pill);
}
.hero__eyebrow .dot {
  width: 7px;
  height: 7px;
  background: var(--accent);
  border-radius: 50%;
  box-shadow: 0 0 0 4px rgba(0, 194, 168, 0.28);
}
.hero__title {
  font-size: clamp(32px, 4.6vw, 56px);
  color: #fff;
  margin-bottom: 20px;
  line-height: 1.16;
}
.hero__title em {
  font-style: normal;
  background: linear-gradient(120deg, #7ee7d5 0%, #8fd0ff 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hero__sub {
  max-width: 560px;
  font-size: 17px;
  color: rgba(255, 255, 255, 0.78);
  margin-bottom: 32px;
}
.hero__actions { margin-bottom: 40px; }

.hero__stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
  max-width: 560px;
  padding-top: 28px;
  border-top: 1px solid rgba(255, 255, 255, 0.16);
}
.hero__stat b {
  display: block;
  font-size: 30px;
  font-weight: 800;
  color: #fff;
  letter-spacing: -0.02em;
}
.hero__stat span {
  font-size: 13px;
  color: rgba(255, 255, 255, 0.68);
}

.hero__visual { position: relative; }
.hero__visual img {
  width: 100%;
  border-radius: var(--radius-lg);
  box-shadow: 0 30px 80px rgba(3, 14, 38, 0.55);
}
.hero__badge {
  position: absolute;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 18px;
  font-size: 14px;
  font-weight: 600;
  color: var(--text);
  background: rgba(255, 255, 255, 0.96);
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  animation: floatY 4.5s ease-in-out infinite;
}
.hero__badge small { display: block; font-weight: 500; color: var(--text-3); font-size: 12px; }
.hero__badge--tl { top: 26px; left: -28px; }
.hero__badge--br { bottom: 30px; right: -22px; animation-delay: 1.4s; }
.hero__badge .ico {
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  color: #fff;
  background: var(--grad-primary);
  border-radius: 10px;
}

@keyframes floatY {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

/* 首屏下方的合作/信任条 */
.trust-bar {
  padding: 34px 0;
  background: #fff;
  border-bottom: 1px solid var(--border);
}
.trust-bar__inner {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 14px 40px;
}
.trust-bar__label { font-size: 14px; color: var(--text-3); }
.trust-bar__item {
  font-size: 16px;
  font-weight: 700;
  color: var(--text-2);
  opacity: 0.72;
  transition: opacity 0.25s var(--ease), color 0.25s var(--ease);
}
.trust-bar__item:hover { opacity: 1; color: var(--primary); }

/* ----------------------------- 7. 卡片 ----------------------------- */
.card {
  position: relative;
  padding: 32px 28px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease),
    border-color 0.3s var(--ease);
}
.card:hover {
  transform: translateY(-6px);
  border-color: rgba(22, 93, 255, 0.35);
  box-shadow: var(--shadow);
}
.card__icon {
  display: grid;
  place-items: center;
  width: 54px;
  height: 54px;
  margin-bottom: 20px;
  color: #fff;
  background: var(--grad-primary);
  border-radius: 16px;
  box-shadow: var(--shadow-primary);
}
.card__icon svg { width: 26px; height: 26px; }
.card h3 { font-size: 19px; margin-bottom: 10px; }
.card p { font-size: 15px; color: var(--text-2); margin: 0; }

.card--flat { box-shadow: none; background: var(--bg-soft); border-color: transparent; }
.card--flat:hover { background: #fff; border-color: var(--border); }
.card--soft { background: var(--bg-soft); border-color: transparent; }

.card__link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-top: 16px;
  font-size: 14px;
  font-weight: 600;
}

/* 场景卡片（图文并茂） */
.scenario-card {
  position: relative;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease);
}
.scenario-card:hover { transform: translateY(-6px); box-shadow: var(--shadow); }
.scenario-card__media { position: relative; aspect-ratio: 16 / 10; overflow: hidden; }
.scenario-card__media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.6s var(--ease);
}
.scenario-card:hover .scenario-card__media img { transform: scale(1.06); }
.scenario-card__no {
  position: absolute;
  top: 14px;
  left: 14px;
  padding: 4px 12px;
  font-size: 12px;
  font-weight: 700;
  color: #fff;
  background: rgba(7, 22, 48, 0.62);
  backdrop-filter: blur(6px);
  border-radius: var(--radius-pill);
}
.scenario-card__body { padding: 26px 26px 30px; flex: 1; }
.scenario-card__body h3 { font-size: 18px; margin-bottom: 8px; }
.scenario-card__body p { font-size: 15px; color: var(--text-2); margin: 0; }

/* 优势卡片（深色区块内） */
.advantage {
  padding: 30px 26px;
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.14);
  transition: transform 0.3s var(--ease), background 0.3s var(--ease);
}
.advantage:hover { transform: translateY(-6px); background: rgba(255, 255, 255, 0.11); }
.advantage__icon {
  display: grid;
  place-items: center;
  width: 50px;
  height: 50px;
  margin-bottom: 18px;
  color: #06224f;
  background: linear-gradient(135deg, #7ee7d5, #b7e1ff);
  border-radius: 14px;
}
.advantage h3 { font-size: 18px; margin-bottom: 8px; }
.advantage p { font-size: 15px; margin: 0; color: rgba(255, 255, 255, 0.72); }

/* 数字统计 */
.stat-card {
  padding: 30px 26px;
  text-align: center;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
}
.stat-card b {
  display: block;
  font-size: 38px;
  font-weight: 800;
  line-height: 1.1;
  background: var(--grad-primary);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.stat-card span { font-size: 14px; color: var(--text-2); }

/* ----------------------------- 8. 下载模块 ----------------------------- */
.download-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(228px, 1fr));
  gap: 22px;
}
.download-card {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  padding: 30px 26px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease),
    border-color 0.3s var(--ease);
}
.download-card:hover {
  transform: translateY(-6px);
  border-color: rgba(22, 93, 255, 0.4);
  box-shadow: var(--shadow);
}
.download-card__icon {
  display: grid;
  place-items: center;
  width: 52px;
  height: 52px;
  margin-bottom: 18px;
  border-radius: 14px;
  background: var(--bg-soft);
}
.download-card__icon svg { width: 28px; height: 28px; }
.download-card h3 { font-size: 18px; margin-bottom: 6px; }
.download-card__meta {
  font-size: 13px;
  color: var(--text-3);
  margin-bottom: 20px;
}
.download-card .btn { margin-top: auto; }
.download-card__tag {
  position: absolute;
  top: 18px;
  right: 18px;
  padding: 3px 10px;
  font-size: 12px;
  font-weight: 600;
  color: var(--primary);
  background: var(--primary-light);
  border-radius: var(--radius-pill);
}

/* 二维码卡片 */
.qr-box {
  display: flex;
  align-items: center;
  gap: 22px;
  padding: 26px 28px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
}
.qr-box img { width: 116px; height: 116px; border-radius: 12px; border: 1px solid var(--border); }
.qr-box h4 { margin-bottom: 6px; font-size: 17px; }
.qr-box p { margin: 0; font-size: 14px; color: var(--text-2); }

/* 下载页顶部横幅 */
.page-hero {
  position: relative;
  padding: calc(var(--header-h) + 64px) 0 64px;
  background: var(--grad-deep);
  color: #fff;
  overflow: hidden;
}
.page-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    radial-gradient(circle at 82% 18%, rgba(0, 194, 168, 0.26), transparent 44%),
    linear-gradient(rgba(255, 255, 255, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.05) 1px, transparent 1px);
  background-size: auto, 46px 46px, 46px 46px;
  pointer-events: none;
}
.page-hero > .container { position: relative; z-index: 1; }
.page-hero__title {
  font-size: clamp(28px, 3.6vw, 44px);
  color: #fff;
  margin-bottom: 14px;
}
.page-hero__desc {
  max-width: 720px;
  margin: 0;
  font-size: 17px;
  color: rgba(255, 255, 255, 0.76);
}
.page-hero--center { text-align: center; }
.page-hero--center .page-hero__desc { margin: 0 auto; }

/* 面包屑 */
.breadcrumb {
  margin-bottom: 18px;
  font-size: 14px;
  color: rgba(255, 255, 255, 0.62);
}
.breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.breadcrumb li + li::before { content: "/"; margin-right: 8px; opacity: 0.5; }
.breadcrumb a { color: rgba(255, 255, 255, 0.78); }
.breadcrumb a:hover { color: #fff; }
.breadcrumb [aria-current] { color: #fff; font-weight: 600; }

/* ----------------------------- 9. 用户评价 ----------------------------- */
.testimonial {
  display: flex;
  flex-direction: column;
  height: 100%;
  padding: 30px 28px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease);
}
.testimonial:hover { transform: translateY(-6px); box-shadow: var(--shadow); }
.testimonial__quote {
  font-size: 15px;
  color: var(--text-2);
  margin: 16px 0 22px;
  flex: 1;
}
.testimonial__stars { display: flex; gap: 3px; color: #ffb400; }
.testimonial__stars svg { width: 16px; height: 16px; }
.testimonial__user {
  display: flex;
  align-items: center;
  gap: 12px;
  padding-top: 18px;
  border-top: 1px solid var(--border);
}
.testimonial__avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  object-fit: cover;
  border: 2px solid var(--primary-light);
}
.testimonial__user b { display: block; font-size: 15px; color: var(--text); }
.testimonial__user b + span { font-size: 13px; color: var(--text-3); }

/* ----------------------------- 10. FAQ 手风琴 ----------------------------- */
.faq-tools {
  display: grid;
  gap: 16px;
  margin-bottom: 36px;
}
.faq-search {
  position: relative;
  max-width: 560px;
  margin: 0 auto;
  width: 100%;
}
.faq-search input {
  width: 100%;
  padding: 15px 18px 15px 50px;
  font-size: 15px;
  font-family: inherit;
  color: var(--text);
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius-pill);
  box-shadow: var(--shadow-sm);
  outline: none;
  transition: border-color 0.25s var(--ease), box-shadow 0.25s var(--ease);
}
.faq-search input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 4px rgba(22, 93, 255, 0.12);
}
.faq-search svg {
  position: absolute;
  left: 18px;
  top: 50%;
  width: 20px;
  height: 20px;
  transform: translateY(-50%);
  color: var(--text-3);
}

.faq-tabs {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
}
.faq-tab {
  padding: 9px 20px;
  font-size: 14px;
  font-weight: 600;
  color: var(--text-2);
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius-pill);
  cursor: pointer;
  transition: all 0.25s var(--ease);
}
.faq-tab:hover { color: var(--primary); border-color: var(--primary); }
.faq-tab.is-active {
  color: #fff;
  background: var(--grad-primary);
  border-color: transparent;
  box-shadow: var(--shadow-primary);
}

.faq-list { display: grid; gap: 14px; max-width: 900px; margin: 0 auto; }
.faq-item {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  transition: border-color 0.25s var(--ease), box-shadow 0.25s var(--ease);
}
.faq-item.is-open { border-color: rgba(22, 93, 255, 0.4); box-shadow: var(--shadow); }
.faq-item[hidden] { display: none; }

.faq-q {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  width: 100%;
  padding: 22px 26px;
  font-size: 16.5px;
  font-weight: 600;
  text-align: left;
  color: var(--text);
  background: transparent;
  border: 0;
  cursor: pointer;
}
.faq-q:hover { color: var(--primary); }
.faq-q__icon {
  flex: 0 0 auto;
  display: grid;
  place-items: center;
  width: 28px;
  height: 28px;
  color: var(--primary);
  background: var(--primary-light);
  border-radius: 50%;
  transition: transform 0.3s var(--ease), background 0.3s var(--ease), color 0.3s var(--ease);
}
.faq-q__icon svg { width: 15px; height: 15px; }
.faq-item.is-open .faq-q__icon {
  transform: rotate(45deg);
  color: #fff;
  background: var(--grad-primary);
}
.faq-a {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s var(--ease);
}
.faq-a__inner {
  padding: 0 26px 24px;
  font-size: 15px;
  color: var(--text-2);
}
.faq-a__inner p:last-child { margin-bottom: 0; }
.faq-a__inner ul { margin-bottom: 0; }

.faq-empty {
  display: none;
  padding: 40px 0;
  text-align: center;
  color: var(--text-3);
}
.faq-empty.is-show { display: block; }

/* ----------------------------- 11. 时间线（关于我们） ----------------------------- */
.timeline { position: relative; max-width: 860px; margin: 0 auto; padding-left: 34px; }
.timeline::before {
  content: "";
  position: absolute;
  left: 8px;
  top: 6px;
  bottom: 6px;
  width: 2px;
  background: linear-gradient(180deg, var(--primary), rgba(22, 93, 255, 0.12));
}
.timeline__item { position: relative; padding: 0 0 34px; }
.timeline__item:last-child { padding-bottom: 0; }
.timeline__item::before {
  content: "";
  position: absolute;
  left: -34px;
  top: 6px;
  width: 18px;
  height: 18px;
  background: #fff;
  border: 3px solid var(--primary);
  border-radius: 50%;
  box-shadow: 0 0 0 4px rgba(22, 93, 255, 0.12);
}
.timeline__year {
  display: inline-block;
  margin-bottom: 6px;
  font-size: 14px;
  font-weight: 700;
  color: var(--primary);
  letter-spacing: 0.04em;
}
.timeline__item h3 { font-size: 18px; margin-bottom: 6px; }
.timeline__item p { font-size: 15px; color: var(--text-2); margin: 0; }

/* 团队 / 价值观 */
.value-card {
  padding: 30px 26px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease);
}
.value-card:hover { transform: translateY(-6px); box-shadow: var(--shadow); }
.value-card__no {
  font-size: 26px;
  font-weight: 800;
  color: var(--primary-light);
  -webkit-text-stroke: 1px var(--primary);
  line-height: 1;
  margin-bottom: 14px;
}
.value-card h3 { font-size: 18px; margin-bottom: 8px; }
.value-card p { font-size: 15px; color: var(--text-2); margin: 0; }

/* 图文分栏 */
.split {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 56px;
  align-items: center;
}
.split--reverse .split__media { order: 2; }
.split__media img { border-radius: var(--radius-lg); box-shadow: var(--shadow); }
.split__body h2 { font-size: clamp(24px, 2.8vw, 34px); }
.split__body > p { font-size: 16px; color: var(--text-2); }

.check-list { margin: 22px 0 0; padding: 0; list-style: none; display: grid; gap: 14px; }
.check-list li { display: flex; gap: 12px; font-size: 15px; color: var(--text-2); }
.check-list svg { flex: 0 0 auto; width: 20px; height: 20px; margin-top: 4px; color: var(--accent); }

/* ----------------------------- 12. 表单组件（通用，当前页面未使用） ----------------------------- */
.contact-layout {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 40px;
  align-items: start;
}

.contact-form {
  padding: 34px 32px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
}
.form-row { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px; }
.field { margin-bottom: 18px; }
.field label {
  display: block;
  margin-bottom: 8px;
  font-size: 14px;
  font-weight: 600;
  color: var(--text);
}
.field label .req { color: #f53f3f; margin-left: 3px; }
.input,
.textarea,
.select {
  width: 100%;
  padding: 12px 16px;
  font-size: 15px;
  font-family: inherit;
  color: var(--text);
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  outline: none;
  transition: border-color 0.25s var(--ease), box-shadow 0.25s var(--ease), background 0.25s var(--ease);
}
.input:focus,
.textarea:focus,
.select:focus {
  background: #fff;
  border-color: var(--primary);
  box-shadow: 0 0 0 4px rgba(22, 93, 255, 0.1);
}
.textarea { min-height: 140px; resize: vertical; }
.form-note { font-size: 13px; color: var(--text-3); margin: 14px 0 0; }
.form-tip {
  display: none;
  margin-top: 14px;
  padding: 12px 16px;
  font-size: 14px;
  border-radius: var(--radius-sm);
}
.form-tip.is-show { display: block; }
.form-tip.is-ok { color: #0f7a3d; background: #e8f8ee; }
.form-tip.is-err { color: #b62222; background: #ffecec; }

.info-card {
  display: flex;
  gap: 16px;
  padding: 24px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease);
}
.info-card:hover { transform: translateY(-4px); box-shadow: var(--shadow); }
.info-card__icon {
  flex: 0 0 auto;
  display: grid;
  place-items: center;
  width: 48px;
  height: 48px;
  color: #fff;
  background: var(--grad-primary);
  border-radius: 14px;
}
.info-card h3 { font-size: 16px; margin-bottom: 4px; }
.info-card p { margin: 0; font-size: 15px; color: var(--text-2); }
.info-card a { font-weight: 600; }

.map-embed {
  margin-top: 28px;
  overflow: hidden;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  aspect-ratio: 16 / 9;
  background: var(--bg-soft);
}
.map-embed iframe { width: 100%; height: 100%; border: 0; display: block; }

/* ----------------------------- 13. CTA 区块 ----------------------------- */
.cta-band {
  position: relative;
  padding: 74px 0;
  background: var(--grad-deep);
  color: #fff;
  overflow: hidden;
  text-align: center;
}
.cta-band::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: radial-gradient(circle at 50% 0%, rgba(0, 194, 168, 0.28), transparent 52%);
  pointer-events: none;
}
.cta-band > .container { position: relative; z-index: 1; }
.cta-band h2 { color: #fff; font-size: clamp(24px, 3vw, 36px); margin-bottom: 14px; }
.cta-band p { color: rgba(255, 255, 255, 0.76); max-width: 640px; margin: 0 auto 30px; }

/* ----------------------------- 14. 页脚 ----------------------------- */
.site-footer {
  padding: 66px 0 0;
  background: #061530;
  color: rgba(255, 255, 255, 0.66);
  font-size: 14px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.8fr 1fr 1fr;
  gap: 40px;
  padding-bottom: 48px;
}
.site-footer .brand { color: #fff; margin-bottom: 16px; }
.site-footer .brand:hover { color: #fff; }
.footer-about p { max-width: 320px; margin-bottom: 20px; color: rgba(255, 255, 255, 0.62); }

.footer-col h4 {
  margin-bottom: 18px;
  font-size: 15px;
  color: #fff;
  font-weight: 700;
}
.footer-col ul { margin: 0; padding: 0; list-style: none; display: grid; gap: 12px; }
.footer-col a { color: rgba(255, 255, 255, 0.66); }
.footer-col a:hover { color: #fff; }

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 22px 0;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  font-size: 13px;
  color: rgba(255, 255, 255, 0.5);
}
.footer-bottom a { color: rgba(255, 255, 255, 0.5); }
.footer-bottom a:hover { color: #fff; }
.footer-bottom__links { display: flex; flex-wrap: wrap; gap: 18px; }

/* ----------------------------- 15. 返回顶部 ----------------------------- */
.to-top {
  position: fixed;
  right: 26px;
  bottom: 26px;
  z-index: 90;
  display: grid;
  place-items: center;
  width: 46px;
  height: 46px;
  color: #fff;
  background: var(--grad-primary);
  border: 0;
  border-radius: 50%;
  box-shadow: var(--shadow-primary);
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: opacity 0.3s var(--ease), visibility 0.3s var(--ease), transform 0.3s var(--ease);
}
.to-top.is-show { opacity: 1; visibility: visible; transform: translateY(0); }
.to-top:hover { transform: translateY(-3px); }
.to-top svg { width: 20px; height: 20px; }

/* ----------------------------- 16. 滚动入场动画 ----------------------------- */
.reveal {
  opacity: 0;
  transform: translateY(26px);
  transition: opacity 0.7s var(--ease), transform 0.7s var(--ease);
  will-change: opacity, transform;
}
.reveal.is-visible { opacity: 1; transform: none; }
.reveal--d1 { transition-delay: 0.08s; }
.reveal--d2 { transition-delay: 0.16s; }
.reveal--d3 { transition-delay: 0.24s; }
.reveal--d4 { transition-delay: 0.32s; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .hero__badge { animation: none; }
  * { animation-duration: 0.001ms !important; transition-duration: 0.001ms !important; }
}

/* ----------------------------- 17. 响应式 ----------------------------- */
@media (max-width: 1080px) {
  .hero__inner { grid-template-columns: 1fr; gap: 48px; }
  .hero__visual { max-width: 620px; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .split { gap: 40px; }
}

@media (max-width: 900px) {
  .section { padding: 66px 0; }
  .grid--4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .contact-layout { grid-template-columns: 1fr; }
  .split { grid-template-columns: 1fr; }
  .split--reverse .split__media { order: 0; }

  /* 移动端导航 */
  .nav-toggle { display: block; }
  .nav {
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    display: block;
    max-height: 0;
    overflow: hidden;
    background: #fff;
    border-bottom: 1px solid transparent;
    transition: max-height 0.35s var(--ease), border-color 0.35s var(--ease);
  }
  .nav.is-open { max-height: 420px; border-bottom-color: var(--border); box-shadow: var(--shadow); }
  .nav__list { flex-direction: column; align-items: stretch; gap: 0; padding: 10px 24px 20px; }
  .nav__link { padding: 14px 12px; border-radius: var(--radius-sm); font-size: 16px; }
  .nav__link.is-active::after { display: none; }
  .nav__link.is-active { background: var(--primary-light); }
  .header-actions .btn--primary { display: none; }
}

@media (max-width: 640px) {
  .container { padding: 0 18px; }
  .section { padding: 54px 0; }
  .grid--2, .grid--3, .grid--4 { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; gap: 32px; }
  .form-row { grid-template-columns: 1fr; }
  .hero__stats { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 12px; }
  .hero__stat b { font-size: 24px; }
  .hero__badge { display: none; }
  .hero { padding-top: calc(var(--header-h) + 56px); padding-bottom: 64px; }
  .page-hero { padding-top: calc(var(--header-h) + 44px); }
  .qr-box { flex-direction: column; text-align: center; }
  .faq-q { padding: 18px 18px; font-size: 15.5px; }
  .faq-a__inner { padding: 0 18px 20px; }
  .contact-form { padding: 24px 20px; }
  .footer-bottom { flex-direction: column; text-align: center; }
  .to-top { right: 16px; bottom: 16px; }
  .download-card { align-items: stretch; }
}

/* ----------------------------- 18. 打印 ----------------------------- */
@media print {
  .site-header, .to-top, .cta-band, .site-footer { display: none; }
  body { color: #000; }
}