/* ============================================================
   品牌视觉：小蓝视频 · 生活不止所见
   设计语言：轻盈水墨 + 数字蓝调 + 气泡纸张
   色彩：冰蓝白 / 深海蓝 / 薄荷青 / 珊瑚粉
   ============================================================ */

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

:root {
  --c-primary: #1479FF;
  --c-primary-dark: #0D60D6;
  --c-primary-mist: rgba(20,121,255,0.08);
  --c-teal: #19C3B5;
  --c-teal-soft: rgba(25,195,181,0.10);
  --c-coral: #FF5E78;
  --c-coral-soft: rgba(255,94,120,0.10);
  --c-sun: #FFC24D;
  --c-sun-soft: rgba(255,194,77,0.18);
  --c-ink: #0B2545;
  --c-muted: #607A96;
  --c-bg: #F5FAFD;
  --c-bg-soft: #EAF6FA;
  --c-card: #FFFFFF;
  --c-border: rgba(11,37,69,0.09);
  --radius-xl: 32px;
  --radius-lg: 24px;
  --radius-md: 18px;
  --radius-xs: 12px;
  --shadow-card: 0 10px 30px rgba(16,94,193,0.07);
  --shadow-hover: 0 20px 48px rgba(16,94,193,0.15);
  --shadow-primary: 0 12px 30px rgba(20,121,255,0.30);
}

body {
  font-family: system-ui, 'PingFang SC', 'Microsoft YaHei', sans-serif;
  overflow-x: hidden;
  background: var(--c-bg);
  color: var(--c-ink);
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

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

::-webkit-scrollbar { width: 10px; }
::-webkit-scrollbar-track { background: var(--c-bg-soft); }
::-webkit-scrollbar-thumb {
  background: linear-gradient(var(--c-primary), var(--c-teal));
  border-radius: 20px;
}
::-webkit-scrollbar-thumb:hover { background: var(--c-primary-dark); }

a { color: var(--c-primary); text-decoration: none; }
img { max-width: 100%; display: block; }
h1,h2,h3,h4 { line-height: 1.25; letter-spacing: -0.015em; }

/* 核心布局 — 必须居中 */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.section {
  padding: 96px 0;
  position: relative;
}

.section:nth-child(even) {
  background:
    radial-gradient(circle at 5% 10%, rgba(20,121,255,0.06), transparent 30%),
    radial-gradient(circle at 95% 80%, rgba(25,195,181,0.08), transparent 30%),
    linear-gradient(180deg, #F4FAFD, #F2FBFB);
}

/* 导航 — 固定顶部 */
.site-header {
  position: fixed;
  top: 0; left: 0; width: 100%;
  z-index: 1000;
  background: rgba(247, 252, 255, 0.72);
  backdrop-filter: blur(22px) saturate(1.6);
  -webkit-backdrop-filter: blur(22px) saturate(1.6);
  border-bottom: 1px solid rgba(11,37,69,0.06);
  box-shadow: 0 1px 24px rgba(20,80,140,0.04);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 900;
  font-size: 1.32rem;
  text-decoration: none;
  color: var(--c-ink);
  letter-spacing: -0.02em;
  transition: opacity .25s;
}

.logo:hover { opacity: .82; }

.logo-icon {
  width: 40px;
  height: 40px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  background:
    radial-gradient(circle at 30% 30%, rgba(255,255,255,0.4), transparent 45%),
    linear-gradient(140deg, var(--c-primary) 0%, var(--c-teal) 110%);
  color: #fff;
  box-shadow: 0 8px 22px rgba(20,121,255,0.32);
  position: relative;
}

.logo-icon::after {
  content: '';
  width: 0;
  height: 0;
  border-left: 9px solid #fff;
  border-top: 6px solid transparent;
  border-bottom: 6px solid transparent;
  display: block;
  margin-left: 3px;
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 30px;
  list-style: none;
}

.main-nav a {
  text-decoration: none;
  font-size: 0.92rem;
  font-weight: 550;
  color: var(--c-ink);
  position: relative;
  padding: 4px 0;
  transition: color .25s;
}

.main-nav a::after {
  content: '';
  position: absolute;
  left: 0; bottom: -3px;
  width: 100%; height: 2px;
  border-radius: 4px;
  background: linear-gradient(90deg, var(--c-primary), var(--c-teal));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform .45s cubic-bezier(.2,.8,.25,1);
}

.main-nav a:hover { color: var(--c-primary); }
.main-nav a:hover::after { transform: scaleX(1); }

.nav-cta {
  padding: 10px 24px !important;
  border-radius: 100px;
  color: #fff !important;
  font-weight: 650 !important;
  background: linear-gradient(130deg, var(--c-primary), var(--c-teal));
  box-shadow: 0 10px 26px rgba(20,121,255,0.30);
  transition: all .4s cubic-bezier(.2,.8,.3,1) !important;
}

.nav-cta::after { display: none !important; }

.nav-cta:hover {
  color: #fff !important;
  transform: translateY(-2px);
  box-shadow: 0 14px 32px rgba(20,121,255,0.42);
}

.menu-toggle {
  display: none;
  background: var(--c-coral-soft);
  border: 1px solid rgba(255,94,120,0.2);
  border-radius: 14px;
  width: 44px;
  height: 44px;
  cursor: pointer;
  justify-content: center;
  align-items: center;
  position: relative;
}

.menu-toggle::before {
  content: '';
  width: 18px;
  height: 2px;
  border-radius: 4px;
  background: var(--c-coral);
  box-shadow: 0 -6px 0 var(--c-coral), 0 6px 0 var(--c-coral);
}

/* 首页 Hero */
.hero {
  min-height: 92vh;
  padding: 132px 24px 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 64px;
  max-width: 1320px;
  margin: 0 auto;
  position: relative;
  isolation: isolate;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  z-index: -1;
  top: 70px;
  right: -12%;
  width: 600px;
  height: 600px;
  border-radius: 100px;
  background:
    radial-gradient(circle at 20% 30%, rgba(25,195,181,0.22), transparent 40%),
    radial-gradient(circle at 80% 70%, rgba(20,121,255,0.16), transparent 50%);
  transform: rotate(15deg);
}

.hero::after {
  content: '';
  position: absolute;
  z-index: -1;
  bottom: 40px;
  left: -80px;
  width: 286px;
  height: 286px;
  background-image: radial-gradient(var(--c-coral) 2.4px, transparent 2.4px);
  background-size: 22px 22px;
  opacity: 0.15;
  pointer-events: none;
}

.hero-content {
  max-width: 640px;
  flex: 0 1 640px;
  position: relative;
  z-index: 2;
  padding: 24px 0;
}

.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.86rem;
  font-weight: 700;
  padding: 8px 20px;
  border-radius: 60px;
  margin-bottom: 22px;
  background: var(--c-primary-mist);
  border: 1px solid rgba(20,121,255,0.18);
  color: var(--c-primary-dark);
  letter-spacing: 0.04em;
  backdrop-filter: blur(8px);
}

.hero-eyebrow::before {
  content: '';
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--c-coral);
  box-shadow: 0 0 0 5px rgba(255,94,120,0.18);
}

.hero h1 {
  font-size: clamp(2.6rem, 5.6vw, 4.6rem);
  line-height: 1.14;
  font-weight: 900;
  letter-spacing: -0.03em;
  margin-bottom: 24px;
  color: var(--c-ink);
}

.hero p {
  font-size: 1.12rem;
  opacity: 0.78;
  color: var(--c-muted);
  max-width: 560px;
  margin-bottom: 34px;
  line-height: 1.85;
}

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

.hero-image {
  flex: 0 1 520px;
  position: relative;
  border-radius: var(--radius-xl);
  overflow: hidden;
  border: 8px solid #fff;
  box-shadow:
    0 34px 70px rgba(16,94,193,0.20),
    0 0 0 1px var(--c-border);
  transform: rotate(2deg);
  transition: transform .6s cubic-bezier(.2,.8,.2,1), box-shadow .6s;
}

.hero-image:hover {
  transform: rotate(0deg) translateY(-5px);
  box-shadow:
    0 44px 90px rgba(16,94,193,0.28),
    0 0 0 1px var(--c-border);
}

.hero-image img {
  width: 100%;
  height: 100%;
  min-height: 420px;
  object-fit: cover;
  transform: scale(1.02);
  transition: transform 1.2s cubic-bezier(.2,.8,.2,1);
}

.hero-image:hover img { transform: scale(1.08); }

.hero-image::before {
  content: '';
  position: absolute;
  inset: 0;
  z-index: 1;
  background: linear-gradient(to top, rgba(11,37,69,0.18), transparent 40%);
}

.hero-image::after {
  content: '';
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  z-index: 3;
  width: 84px;
  height: 84px;
  border-radius: 50%;
  background: rgba(255,255,255,0.9);
  backdrop-filter: blur(8px);
  box-shadow: 0 14px 38px rgba(20,80,140,0.45);
  transition: transform .45s cubic-bezier(.2,.8,.3,1), background .3s;
}

.hero-image::marker { display:none; }

/* 由于::after已占播放按钮，用额外伪元素不可行，利用style化CSS三角通过background实现 */
.hero-image { z-index: 0; }
.hero-image img { position: relative; z-index: 0; }

.hero-image > * { position: relative; z-index: 2; }

/* 播放按钮视觉通过 background 绘制 */
.hero-image {
  --play-btn: none;
  cursor: pointer;
}

.hero-image::after {
  content: '';
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'%3E%3Cpath fill='%231479FF' d='M8 5v14l11-7z'/%3E%3C/svg%3E");
  background-size: 34px;
  background-position: center;
  background-repeat: no-repeat;
}

.hero-image:hover::after {
  transform: translate(-50%, -50%) scale(1.08);
  background-color: #fff;
}

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 14px 32px;
  border-radius: 100px;
  font-weight: 650;
  font-size: 0.92rem;
  cursor: pointer;
  border: none;
  text-decoration: none;
  transition: transform .35s cubic-bezier(.2,.8,.3,1), box-shadow .35s, background .35s;
  letter-spacing: 0.02em;
  position: relative;
  overflow: hidden;
  white-space: nowrap;
}

.btn:active { transform: scale(0.96); }

.btn-primary {
  color: #fff;
  background: linear-gradient(130deg, var(--c-primary), #22A2FF 60%, var(--c-teal));
  box-shadow: var(--shadow-primary);
}

.btn-primary::before {
  content: '';
  position: absolute;
  top: 0; left: -70%;
  width: 40%; height: 100%;
  background: linear-gradient(105deg, transparent, rgba(255,255,255,0.5), transparent);
  transform: skewX(-25deg);
  transition: left 0.7s ease;
}

.btn-primary:hover {
  transform: translateY(-3px);
  box-shadow: 0 18px 44px rgba(20,121,255,0.45);
}

.btn-primary:hover::before { left: 130%; }

.btn-outline {
  background: rgba(255,255,255,0.6);
  border: 2px solid var(--c-primary);
  color: var(--c-primary);
  box-shadow: 0 6px 18px rgba(20,121,255,0.06);
}

.btn-outline:hover {
  background: var(--c-primary);
  color: #fff;
  transform: translateY(-3px);
  box-shadow: 0 18px 36px rgba(20,121,255,0.30);
}

/* 标签/标题 */
.section-label {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 750;
  letter-spacing: 2.2px;
  margin-bottom: 16px;
  position: relative;
  padding: 7px 20px 7px 38px;
  border-radius: 80px;
  background: var(--c-primary-mist);
  color: var(--c-primary-dark);
  border: 1px solid rgba(20,121,255,0.14);
  text-transform: uppercase;
}

.section-label::before {
  content: '';
  position: absolute;
  left: 18px;
  top: 50%;
  transform: translateY(-50%);
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--c-coral);
  box-shadow: 11px 0 0 var(--c-teal);
}

.section-title {
  font-size: clamp(1.8rem, 3vw, 2.6rem);
  margin-bottom: 14px;
  font-weight: 850;
  color: var(--c-ink);
  line-height: 1.25;
}

.section-title::before {
  content: '';
  display: block;
  width: 44px;
  height: 4px;
  border-radius: 100px;
  background: linear-gradient(90deg, var(--c-primary), var(--c-teal));
  margin-bottom: 18px;
}

.text-center .section-title::before,
.section-title.text-center::before {
  margin-left: auto;
  margin-right: auto;
}

.section-desc {
  max-width: 620px;
  font-size: 1.02rem;
  color: var(--c-muted);
  line-height: 1.85;
  margin-bottom: 42px;
}

.text-center .section-desc {
  margin-left: auto;
  margin-right: auto;
}

/* 卡片网格 */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 26px;
}

.category-card {
  background: var(--c-card);
  border-radius: var(--radius-lg);
  padding: 30px 26px;
  border: 1px solid var(--c-border);
  position: relative;
  overflow: hidden;
  transition: transform 0.45s cubic-bezier(0.15, 0.9, 0.3, 1.1), box-shadow 0.45s;
  box-shadow: var(--shadow-card);
}

.category-card::before {
  content: '';
  position: absolute;
  right: -42px;
  top: -42px;
  width: 130px;
  height: 130px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(20,121,255,0.12), rgba(25,195,181,0.06) 55%, transparent 75%);
  transition: transform .7s ease;
  z-index: 0;
}

.category-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-hover);
  border-color: rgba(20,121,255,0.24);
}

.category-card:hover::before { transform: scale(2.4); }

.category-card > * { position: relative; z-index: 1; }

.card-icon {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  font-size: 1.4rem;
  color: #fff !important;
  background: linear-gradient(140deg, var(--c-primary), #5BB5FF);
  box-shadow: 0 12px 30px rgba(20,121,255,0.25);
  transition: transform .45s;
}

.category-card:hover .card-icon { transform: rotate(-8deg) scale(1.08); }

.category-card:nth-child(4n+2) .card-icon {
  background: linear-gradient(140deg, var(--c-teal), #55E0C9);
  box-shadow: 0 12px 30px rgba(25,195,181,0.26);
}

.category-card:nth-child(4n+3) .card-icon {
  background: linear-gradient(140deg, var(--c-coral), #FF9D8E);
  box-shadow: 0 12px 30px rgba(255,94,120,0.26);
}

.category-card:nth-child(4n+4) .card-icon {
  background: linear-gradient(140deg, var(--c-sun), #FF9F43);
  box-shadow: 0 12px 30px rgba(255,194,77,0.32);
}

.category-card h3 {
  font-size: 1.12rem;
  font-weight: 800;
  margin-bottom: 6px;
  color: var(--c-ink);
}

.category-card p {
  font-size: 0.88rem;
  color: var(--c-muted);
  margin-bottom: 14px;
  line-height: 1.7;
}

.card-link {
  font-weight: 700;
  font-size: 0.86rem;
  text-decoration: none;
  color: var(--c-primary);
  display: inline-block;
  position: relative;
  letter-spacing: 0.02em;
  transition: letter-spacing .35s;
}

.card-link::after {
  content: '→';
  display: inline-block;
  margin-left: 6px;
  transition: transform .3s;
}

.card-link:hover { letter-spacing: 0.08em; }
.card-link:hover::after { transform: translateX(5px); }

/* 特性块 */
.feature-block {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}

.feature-block + .feature-block { margin-top: 110px; }

.feature-block:nth-child(even) .feature-image {
  order: 2;
}

.feature-image {
  position: relative;
  border-radius: var(--radius-xl);
  overflow: hidden;
  border: 6px solid #fff;
  box-shadow:
    0 24px 54px rgba(16,94,193,0.12),
    12px 12px 0 rgba(20,121,255,0.08),
    24px 24px 0 rgba(25,195,181,0.05);
  transition: transform .6s, box-shadow .6s;
}

.feature-image:hover {
  transform: translateY(-6px) rotate(1deg);
  box-shadow:
    0 40px 70px rgba(16,94,193,0.18),
    12px 12px 0 rgba(20,121,255,0.12),
    24px 24px 0 rgba(25,195,181,0.08);
}

.feature-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  min-height: 320px;
}

.feature-text { position: relative; }

.feature-text .section-label { margin-bottom: 14px; }

.feature-text h3 {
  font-size: clamp(1.6rem, 2.4vw, 2.1rem);
  font-weight: 850;
  margin-bottom: 12px;
}

.feature-text > p {
  color: var(--c-muted);
  margin-bottom: 22px;
  font-size: 1rem;
  line-height: 1.9;
}

.feature-list {
  list-style: none;
  margin: 18px 0 30px;
}

.feature-list li {
  padding: 8px 0;
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--c-ink);
  font-weight: 550;
  font-size: 0.96rem;
}

.feature-list li::before {
  content: '✓';
  flex: 0 0 26px;
  height: 26px;
  border-radius: 50%;
  background: linear-gradient(140deg, var(--c-teal), #6CE0D0);
  color: #fff;
  font-size: 0.75rem;
  font-weight: 900;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 6px 14px rgba(25,195,181,0.28);
}

/* 数据条 */
.stats-bar {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 26px;
  text-align: center;
}

.stat-item {
  padding: 34px 20px 28px;
  border-radius: var(--radius-lg);
  background: var(--c-card);
  border: 1px solid var(--c-border);
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-card);
  transition: transform .45s, box-shadow .45s;
}

.stat-item::before {
  content: '';
  position: absolute;
  top: 0; left: 20%; right: 20%;
  height: 4px;
  border-radius: 0 0 12px 12px;
  background: linear-gradient(90deg, var(--c-primary), var(--c-teal));
}

.stat-item:nth-child(2)::before { background: linear-gradient(90deg, var(--c-teal), #5CE0CF); }
.stat-item:nth-child(3)::before { background: linear-gradient(90deg, var(--c-coral), #FFB29B); }
.stat-item:nth-child(4)::before { background: linear-gradient(90deg, var(--c-sun), #FFC24D); }

.stat-item:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-hover);
}

.stat-item:nth-child(2) { background: linear-gradient(160deg, #fff, rgba(25,195,181,0.04)); }
.stat-item:nth-child(3) { background: linear-gradient(160deg, #fff, rgba(255,94,120,0.04)); }
.stat-item:nth-child(4) { background: linear-gradient(160deg, #fff, rgba(255,194,77,0.05)); }

.stat-number {
  font-size: 2.6rem;
  font-weight: 950;
  color: var(--c-ink);
  letter-spacing: -0.03em;
  line-height: 1.15;
  background: linear-gradient(130deg, var(--c-primary) 0%, var(--c-teal) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
}

.stat-item:nth-child(3) .stat-number {
  background: linear-gradient(130deg, var(--c-coral), #FF9F43);
  -webkit-background-clip: text;
  background-clip: text;
}

.stat-label {
  font-size: 0.92rem;
  color: var(--c-muted);
  margin-top: 6px;
  font-weight: 550;
}

/* 内容墙 */
.content-wall {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 26px;
}

.content-wall-item {
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: #fff;
  border: 1px solid var(--c-border);
  box-shadow: var(--shadow-card);
  position: relative;
  transition: transform 0.45s, box-shadow 0.45s, border-color .35s;
}

.content-wall-item:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-hover);
  border-color: rgba(20,121,255,0.25);
}

.content-wall-item .content-wall-thumb {
  overflow: hidden;
  position: relative;
}

.content-wall-item img {
  width: 100%;
  height: 200px;
  object-fit: cover;
  transition: transform 1s cubic-bezier(.2,.8,.2,1);
}

.content-wall-item:hover img { transform: scale(1.09); }

.content-wall-item .tag {
  position: absolute;
  left: 14px;
  top: 14px;
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(10px);
  border-radius: 60px;
  padding: 5px 14px;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--c-primary-dark);
  box-shadow: 0 4px 14px rgba(11,37,69,0.1);
  z-index: 2;
}

.content-wall-item::before {
  content: '';
  position: absolute;
  top: 0; left: 0;
  width: 100%; height: 200px;
  background: linear-gradient(to top, transparent 40%, rgba(20,121,255,0.18));
  opacity: 0;
  transition: opacity .5s;
  z-index: 1;
  pointer-events: none;
}

.content-wall-item:hover::before { opacity: 1; }

.content-wall-body {
  padding: 22px 22px 24px;
}

.content-wall-body h3 {
  font-size: 1.06rem;
  font-weight: 800;
  margin-bottom: 8px;
  color: var(--c-ink);
  line-height: 1.5;
  transition: color .3s;
}

.content-wall-item:hover .content-wall-body h3 { color: var(--c-primary); }

.content-wall-body p {
  font-size: 0.88rem;
  color: var(--c-muted);
  line-height: 1.7;
}

.content-wall-body .meta {
  margin-top: 14px;
  font-size: 0.8rem;
  color: var(--c-muted);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.content-wall-body a {
  color: var(--c-primary);
  font-weight: 650;
}

/* FAQ */
.faq-list {
  max-width: 800px;
  margin: 0 auto;
}

.faq-item {
  background: #fff;
  border: 1px solid var(--c-border);
  border-radius: var(--radius-md);
  margin-bottom: 12px;
  overflow: hidden;
  cursor: pointer;
  transition: border-color .3s, box-shadow .3s, transform .3s;
}

.faq-item:hover {
  border-color: rgba(20,121,255,0.28);
  box-shadow: 0 8px 24px rgba(16,94,193,0.07);
}

.faq-item.open {
  border-color: rgba(20,121,255,0.38);
  box-shadow: 0 12px 32px rgba(20,121,255,0.1);
}

.faq-question {
  padding: 18px 22px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  font-size: 0.98rem;
  color: var(--c-ink);
}

.faq-question::after {
  content: '+';
  font-size: 1.5rem;
  font-weight: 300;
  color: var(--c-primary);
  width: 30px;
  height: 30px;
  flex: 0 0 30px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--c-primary-mist);
  transition: transform .45s cubic-bezier(.2,.8,.3,1), background .3s, color .3s;
}

.faq-item.open .faq-question::after {
  transform: rotate(135deg);
  background: var(--c-primary);
  color: #fff;
}

.faq-answer {
  padding: 0 22px 20px;
  display: none;
  font-size: 0.93rem;
  color: var(--c-muted);
  line-height: 1.85;
  animation: faqSlide .4s ease;
}

.faq-item.open .faq-answer { display: block; }

@keyframes faqSlide {
  from { opacity: 0; transform: translateY(-8px); }
  to { opacity: 1; transform: translateY(0); }
}

/* CTA横幅 */
.cta-banner {
  padding: 64px 40px;
  text-align: center;
  border-radius: var(--radius-xl);
  color: #fff;
  background:
    radial-gradient(circle at 12% 20%, rgba(255,255,255,0.25), transparent 26%),
    radial-gradient(circle at 85% 80%, rgba(255,230,90,0.25), transparent 28%),
    radial-gradient(circle at 50% 50%, rgba(255,255,255,0.08), transparent 40%),
    linear-gradient(130deg, #0F5FE8 0%, #1479FF 45%, #10B6C9 120%);
  position: relative;
  overflow: hidden;
  isolation: isolate;
}

.cta-banner::before,
.cta-banner::after {
  content: '';
  position: absolute;
  border-radius: 50%;
  z-index: -1;
  pointer-events: none;
}

.cta-banner::before {
  width: 180px; height: 180px;
  right: -40px; top: -40px;
  border: 30px solid rgba(255,255,255,0.14);
}

.cta-banner::after {
  width: 90px; height: 90px;
  left: 40px; bottom: 30px;
  background: rgba(255,255,255,0.16);
  backdrop-filter: blur(4px);
}

.cta-banner h2 {
  color: #fff;
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  font-weight: 900;
  letter-spacing: -0.02em;
  margin-bottom: 14px;
}

.cta-banner p {
  font-size: 1rem;
  color: rgba(255,255,255,0.92);
  max-width: 560px;
  margin: 0 auto 32px;
  line-height: 1.8;
}

.cta-banner .btn-primary {
  background: #fff;
  color: var(--c-primary-dark);
  box-shadow: 0 14px 32px rgba(5,40,110,0.3);
}

.cta-banner .btn-primary::before {
  background: linear-gradient(105deg, transparent, rgba(20,121,255,0.25), transparent);
}

.cta-banner .btn-primary:hover {
  transform: translateY(-3px) scale(1.02);
  box-shadow: 0 20px 44px rgba(5,40,110,0.4);
}

.cta-banner .btn-outline {
  color: #fff;
  border-color: rgba(255,255,255,0.7);
  background: rgba(255,255,255,0.12);
}

.cta-banner .btn-outline:hover {
  background: #fff;
  color: var(--c-primary-dark);
}

.cta-actions {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}

/* 页脚 */
.site-footer {
  padding: 72px 0 28px;
  background:
    radial-gradient(circle at 80% 0%, rgba(20,121,255,0.07), transparent 30%),
    linear-gradient(180deg, #EAF7FB, #F5FAFD 30%);
  border-top: 1px solid rgba(20,121,255,0.08);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 44px;
}

.footer-brand .logo {
  font-size: 1.25rem;
  margin-bottom: 14px;
}

.footer-brand p {
  color: var(--c-muted);
  font-size: 0.9rem;
  max-width: 280px;
  line-height: 1.8;
}

.footer-col h4 {
  font-size: 0.85rem;
  font-weight: 800;
  letter-spacing: 1.5px;
  color: var(--c-ink);
  margin-bottom: 18px;
}

.footer-col ul {
  list-style: none;
}

.footer-col li {
  margin-bottom: 10px;
}

.footer-col a {
  color: var(--c-muted);
  font-size: 0.9rem;
  transition: color .3s, padding-left .3s;
}

.footer-col a:hover {
  color: var(--c-primary);
  padding-left: 6px;
}

.footer-bottom {
  border-top: 1px solid rgba(11,37,69,0.08);
  margin-top: 48px;
  padding-top: 26px;
  text-align: center;
  font-size: 0.85rem;
  color: var(--c-muted);
}

/* 工具类 */
.text-accent {
  background: linear-gradient(115deg, var(--c-primary) 10%, var(--c-teal) 70%, var(--c-sun) 110%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

.text-center { text-align: center; }
.seo-description {
  max-width: 620px;
  margin: 0 auto 48px;
  color: var(--c-muted);
  line-height: 1.85;
  font-size: 0.98rem;
}

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

/* ⚠️ 响应式 */
@media (max-width: 1024px) {
  .hero {
    gap: 40px;
    padding: 120px 24px 60px;
  }

  .hero-image {
    flex-basis: 420px;
  }
}

@media (max-width: 900px) {
  .hero {
    flex-direction: column;
    align-items: flex-start;
  }

  .hero-content { max-width: 100%; }

  .hero-image {
    flex: 1 1 100%;
    width: 100%;
  }

  .hero-image img { min-height: 300px; }

  .feature-block {
    grid-template-columns: 1fr;
    gap: 48px;
  }

  .feature-block:nth-child(even) .feature-image { order: 0; }

  .feature-image img { min-height: 0; }
}

@media (max-width: 768px) {
  .feature-block { grid-template-columns: 1fr; }
  .stats-bar { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }

  .main-nav { display: none; }
  .menu-toggle {
    display: flex;
  }

  .menu-toggle:hover::before {
    box-shadow: 0 -6px 0 var(--c-coral), 0 6px 0 var(--c-coral);
  }

  .main-nav.open {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    position: absolute;
    top: 72px;
    left: 0;
    width: 100%;
    background: rgba(255,255,255,0.98);
    backdrop-filter: blur(20px);
    padding: 20px 28px 26px;
    gap: 16px;
    border-bottom: 1px solid var(--c-border);
    box-shadow: 0 24px 48px rgba(16,94,193,0.12);
    z-index: 999;
    animation: navFade .3s ease;
  }

  .main-nav.open li { display: block; width: 100%; }

  .main-nav.open a {
    display: block;
    padding: 8px 0;
    font-size: 1.05rem;
  }

  .main-nav.open .nav-cta {
    display: inline-block;
    text-align: center;
    margin-top: 6px;
  }

  .section { padding: 72px 0; }
}

@keyframes navFade {
  from { opacity: 0; transform: translateY(-10px); }
  to { opacity: 1; transform: translateY(0); }
}

@media (max-width: 480px) {
  .cards-grid,
  .content-wall,
  .stats-bar {
    grid-template-columns: 1fr;
  }

  .footer-grid { grid-template-columns: 1fr; }
  .hero-buttons { flex-direction: column; align-items: stretch; }

  .hero-buttons .btn {
    width: 100%;
  }

  .cta-banner { padding: 48px 24px; }

  .cta-actions .btn { width: 100%; }

  .section-title { font-size: 1.8rem; }

  .section-label { letter-spacing: 1.6px; }
}