:root {
  --bg: #f7f8fa;
  --bg-2: #eef0f3;
  --surface: #ffffff;
  --surface-soft: #f2f4f7;
  --primary: #1f2937;
  --primary-light: #4b5563;
  --amber: #6b7280;
  --yellow: #9ca3af;
  --accent-gradient: linear-gradient(135deg, #1f2937 0%, #9ca3af 100%);
  --text: #1f2937;
  --text-muted: #6b7280;
  --text-dim: #9ca3af;
  --border: rgba(31, 41, 55, 0.12);
  --radius: 20px;
  --radius-lg: 28px;
  --shadow: 0 20px 50px rgba(31, 41, 55, 0.10);
  --shadow-glow: 0 0 60px rgba(156, 163, 175, 0.22);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  min-width: 320px;
  font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

img {
  max-width: 100%;
  height: auto;
  vertical-align: middle;
}

a {
  text-decoration: none;
  color: inherit;
}

/* 通用容器 */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* 通用标题 */
.section-title {
  position: relative;
  font-size: 36px;
  font-weight: 700;
  color: var(--text);
  line-height: 1.25;
  text-align: center;
  margin: 0 0 14px;
}

.section-title[data-title]::before {
  content: attr(data-title);
  display: block;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 3px;
  text-transform: uppercase;
  color: var(--primary);
  margin-bottom: 12px;
}

.section-title::after {
  content: "";
  display: block;
  width: 60px;
  height: 4px;
  margin: 18px auto 0;
  border-radius: 2px;
  background: var(--accent-gradient);
}

.section-desc {
  font-size: 17px;
  color: var(--text-muted);
  text-align: center;
  max-width: 640px;
  margin: 0 auto 50px;
  line-height: 1.7;
}

/* 背景光晕 */
.glow {
  position: absolute;
  border-radius: 50%;
  filter: blur(100px);
  pointer-events: none;
  opacity: 0.35;
  z-index: 0;
}

/* Banner / Hero */
.banner {
  position: relative;
  width: 100%;
  min-height: 760px;
  padding: 160px 0 110px;
  display: flex;
  align-items: center;
  background:
    radial-gradient(ellipse at 15% 20%, rgba(156, 163, 175, 0.22) 0%, transparent 45%),
    radial-gradient(ellipse at 85% 80%, rgba(31, 41, 55, 0.16) 0%, transparent 45%),
    linear-gradient(180deg, #f2f4f7 0%, #f7f8fa 100%);
  overflow: hidden;
}

.banner .glow-1 {
  width: 700px;
  height: 700px;
  background: var(--yellow);
  top: -220px;
  right: -180px;
}

.banner .glow-2 {
  width: 560px;
  height: 560px;
  background: var(--primary-light);
  bottom: -200px;
  left: -160px;
}

.banner .center {
  position: relative;
  z-index: 2;
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 60px;
}

.banner .center .left {
  flex: 1 1 540px;
  max-width: 640px;
}

.banner .center .left .eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 16px;
  border-radius: 30px;
  background: rgba(31, 41, 55, 0.10);
  border: 1px solid rgba(31, 41, 55, 0.20);
  color: var(--primary);
  font-size: 14px;
  font-weight: 500;
  margin-bottom: 24px;
}

.banner .center .left .eyebrow::before {
  content: "";
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--yellow);
  box-shadow: 0 0 10px var(--yellow);
}

.banner .center .left .title {
  font-size: 56px;
  font-weight: 800;
  color: var(--text);
  line-height: 1.15;
  margin: 0 0 22px;
  letter-spacing: -0.02em;
}

.banner .center .left .title span {
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.banner .center .left .desc {
  font-size: 20px;
  font-weight: 400;
  color: var(--text-muted);
  line-height: 1.75;
  margin: 0 0 16px;
  max-width: 520px;
}

.banner .center .left .actions {
  display: flex;
  align-items: center;
  gap: 18px;
  margin-top: 38px;
  flex-wrap: wrap;
}

.banner .center .left .btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 15px 34px;
  border-radius: 30px;
  background: var(--accent-gradient);
  color: #ffffff;
  font-size: 17px;
  font-weight: 600;
  box-shadow: 0 8px 28px rgba(31, 41, 55, 0.35);
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.banner .center .left .btn:hover {
  transform: translateY(-3px);
  box-shadow: 0 14px 38px rgba(31, 41, 55, 0.45);
}

.banner .center .left .btn-outline {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 30px;
  border-radius: 30px;
  border: 1px solid rgba(31, 41, 55, 0.35);
  background: #ffffff;
  color: var(--primary);
  font-size: 16px;
  font-weight: 600;
  transition: background 0.25s ease, border-color 0.25s ease, color 0.25s ease;
}

.banner .center .left .btn-outline:hover {
  background: var(--surface-soft);
  border-color: var(--primary);
  color: var(--primary);
}

/* Hero 视觉组件 */
.hero-visual {
  flex: 1 1 440px;
  max-width: 520px;
  width: 100%;
  position: relative;
  animation: heroFloat 6s ease-in-out infinite;
}

@keyframes heroFloat {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-14px); }
}

.hero-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
}

.hero-card.main {
  padding: 28px;
  position: relative;
  z-index: 2;
}

.hero-card-header {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 15px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 18px;
}

.hero-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--primary);
  box-shadow: 0 0 0 4px rgba(31, 41, 55, 0.15);
}

/* 关键词排名榜单卡片 */
.rank-card {
  padding: 26px;
}

.rank-badge {
  margin-left: auto;
  font-size: 12px;
  font-weight: 600;
  color: #ffffff;
  background: var(--accent-gradient);
  padding: 4px 12px;
  border-radius: 20px;
  display: inline-flex;
  align-items: center;
}

.rank-badge::before {
  content: "";
  width: 0;
  height: 0;
  margin-right: 5px;
  border-left: 5px solid transparent;
  border-right: 5px solid transparent;
  border-bottom: 7px solid #ffffff;
}

.rank-list {
  list-style: none;
  margin: 0 0 18px;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.rank-list .rank-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 14px;
  background: var(--surface-soft);
  border-radius: 12px;
  transition: background 0.25s ease;
}

.rank-list .rank-item.rank-top {
  background: rgba(31, 41, 55, 0.08);
  border: 1px solid rgba(31, 41, 55, 0.16);
}

.rank-no {
  width: 28px;
  height: 28px;
  flex: none;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
  font-size: 13px;
  font-weight: 700;
  color: #ffffff;
  background: #9ca3af;
}

.rank-top .rank-no {
  background: var(--accent-gradient);
  box-shadow: 0 4px 12px rgba(31, 41, 55, 0.3);
}

.rank-kw {
  flex: 1;
  font-size: 15px;
  font-weight: 600;
  color: var(--text);
}

.rank-pos {
  font-size: 13px;
  font-weight: 800;
  color: var(--primary);
  background: #ffffff;
  padding: 4px 12px;
  border-radius: 20px;
  border: 1px solid rgba(31, 41, 55, 0.15);
}

.rank-stats {
  display: flex;
  gap: 14px;
}

.rank-stats > div {
  flex: 1;
  padding: 14px 16px;
  background: var(--surface-soft);
  border-radius: 12px;
  text-align: center;
}

.rank-stats strong {
  display: block;
  font-size: 22px;
  font-weight: 800;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 4px;
}

.rank-stats span {
  font-size: 12px;
  color: var(--text-muted);
}

.hero-card.float-1,
.hero-card.float-2 {
  position: absolute;
  z-index: 3;
  padding: 16px 20px;
  text-align: center;
  animation: floatBadge 4s ease-in-out infinite;
}

.hero-card.float-1 {
  top: -20px;
  right: -20px;
  animation-delay: 0s;
}

.hero-card.float-2 {
  bottom: 20px;
  right: -30px;
  animation-delay: 1.2s;
}

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

.hero-stars {
  font-size: 18px;
  color: var(--yellow);
  letter-spacing: 1px;
  margin-bottom: 6px;
  text-shadow: 0 1px 2px rgba(156, 163, 175, 0.3);
}

.hero-icon {
  font-size: 26px;
  font-weight: 800;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 4px;
}

.hero-label {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-muted);
}

/* 覆盖主流商店：4 大板块 */
.coverage {
  position: relative;
  padding: 90px 0 110px;
  background: var(--bg-2);
  border-top: 1px solid var(--border);
  overflow: hidden;
}

.coverage::before {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 900px;
  height: 900px;
  background: radial-gradient(circle, rgba(31, 41, 55, 0.07) 0%, transparent 70%);
  pointer-events: none;
}

.coverage-grid {
  position: relative;
  z-index: 2;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.coverage-card {
  position: relative;
  display: flex;
  flex-direction: column;
  padding: 32px 26px 28px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: 0 8px 28px rgba(31, 41, 55, 0.05);
  transition: transform 0.35s ease, box-shadow 0.35s ease, border-color 0.35s ease;
}

.coverage-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--accent-gradient);
  opacity: 0;
  transition: opacity 0.35s ease;
}

.coverage-card:hover {
  transform: translateY(-8px);
  border-color: rgba(31, 41, 55, 0.3);
  box-shadow: var(--shadow-glow);
}

.coverage-card:hover::before {
  opacity: 1;
}

.coverage-icon {
  width: 60px;
  height: 60px;
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 16px;
  background: linear-gradient(135deg, rgba(31, 41, 55, 0.08) 0%, rgba(156, 163, 175, 0.16) 100%);
  border: 1px solid rgba(31, 41, 55, 0.12);
}

.coverage-title {
  font-size: 20px;
  font-weight: 700;
  color: var(--text);
  margin: 0 0 10px;
}

.coverage-desc {
  font-size: 14px;
  color: var(--text-muted);
  line-height: 1.7;
  margin: 0 0 18px;
}

.coverage-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.coverage-tags span {
  display: inline-block;
  font-size: 12px;
  font-weight: 500;
  color: var(--primary);
  background: rgba(31, 41, 55, 0.06);
  border: 1px solid rgba(31, 41, 55, 0.10);
  padding: 4px 10px;
  border-radius: 20px;
  margin-right: 6px;
  margin-bottom: 6px;
  transition: background 0.25s ease, color 0.25s ease, border-color 0.25s ease;
}

.coverage-tags span.tag-hot {
  color: #ffffff;
  background: var(--accent-gradient);
  border-color: transparent;
  font-weight: 600;
  box-shadow: 0 2px 8px rgba(31, 41, 55, 0.18);
}

.coverage-card:hover .coverage-tags span {
  background: rgba(31, 41, 55, 0.10);
}

.coverage-card:hover .coverage-tags span.tag-hot {
  background: var(--accent-gradient);
}

/* 优势部分 */
.advantages {
  position: relative;
  padding: 110px 0 120px;
  background: var(--bg);
  overflow: hidden;
}

.advantages .glow-1 {
  width: 600px;
  height: 600px;
  background: var(--yellow);
  top: -150px;
  left: -200px;
}

.advantages .glow-2 {
  width: 500px;
  height: 500px;
  background: var(--primary-light);
  bottom: -180px;
  right: -150px;
}

.adv-grid {
  position: relative;
  z-index: 2;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.adv-card {
  position: relative;
  padding: 38px 26px 34px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  text-align: center;
  overflow: hidden;
  box-shadow: 0 8px 28px rgba(31, 41, 55, 0.05);
  transition: transform 0.35s ease, box-shadow 0.35s ease, border-color 0.35s ease;
}

.adv-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--accent-gradient);
  opacity: 0.85;
}

.adv-card:hover {
  transform: translateY(-10px);
  border-color: rgba(31, 41, 55, 0.25);
  box-shadow: var(--shadow-glow);
}

.adv-card .img-wrapper {
  width: 110px;
  height: 110px;
  margin: 0 auto 24px;
  background: rgba(31, 41, 55, 0.08);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid rgba(31, 41, 55, 0.12);
}

.adv-card .img-wrapper img {
  max-width: 72%;
  max-height: 72%;
  width: auto;
  height: auto;
}

.adv-card .case-title {
  font-size: 21px;
  font-weight: 700;
  color: var(--text);
  margin: 0 0 12px;
}

.adv-card .case-desc {
  font-size: 15px;
  font-weight: 400;
  color: var(--text-muted);
  line-height: 1.7;
  margin: 0;
}

/* 优化组合 */
.opt-comp {
  position: relative;
  padding: 110px 0 120px;
  background: var(--bg-2);
  border-top: 1px solid var(--border);
  overflow: hidden;
}

.opt-comp::before {
  content: "";
  position: absolute;
  top: -300px;
  right: -300px;
  width: 800px;
  height: 800px;
  background: radial-gradient(circle, rgba(156, 163, 175, 0.12) 0%, transparent 65%);
  pointer-events: none;
}

.opt-grid {
  position: relative;
  z-index: 2;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.opt-card {
  position: relative;
  display: block;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: 0 8px 28px rgba(31, 41, 55, 0.05);
  transition: transform 0.35s ease, box-shadow 0.35s ease, border-color 0.35s ease;
}

.opt-card:hover {
  transform: translateY(-8px);
  border-color: rgba(31, 41, 55, 0.25);
  box-shadow: var(--shadow-glow);
}

.opt-card .img-wrapper {
  width: 100%;
  height: 190px;
  background: linear-gradient(135deg, rgba(31, 41, 55, 0.06) 0%, rgba(156, 163, 175, 0.08) 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.opt-card .img-wrapper img {
  width: auto;
  height: auto;
  max-width: 85%;
  max-height: 85%;
  object-fit: contain;
  transition: transform 0.45s ease;
}

.opt-card:hover .img-wrapper img {
  transform: scale(1.06);
}

.opt-card .text-wrapper {
  padding: 26px 26px 30px;
}

.opt-card .text-title {
  font-size: 20px;
  font-weight: 700;
  color: var(--text);
  margin: 0 0 10px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.opt-card .text-title::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--primary);
  box-shadow: 0 0 10px rgba(31, 41, 55, 0.4);
}

.opt-card .text-desc {
  font-size: 15px;
  font-weight: 400;
  color: var(--text-muted);
  line-height: 1.7;
  margin: 0;
}

.opt-card .opt-more {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-top: 18px;
  font-size: 14px;
  font-weight: 600;
  color: var(--primary);
  transition: gap 0.25s ease, color 0.25s ease;
}

.opt-card .opt-more svg {
  transition: transform 0.25s ease;
}

.opt-card:hover .opt-more {
  gap: 10px;
}

.opt-card:hover .opt-more svg {
  transform: translateX(3px);
}

/* 服务体系 */
.service {
  position: relative;
  padding: 110px 0 120px;
  background: var(--bg);
  overflow: hidden;
}

.service .glow-1 {
  width: 700px;
  height: 700px;
  background: var(--yellow);
  top: -200px;
  right: -250px;
}

.service-flow {
  position: relative;
  z-index: 2;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 22px;
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
}

.flow-step {
  position: relative;
  padding: 36px 24px 32px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  text-align: center;
  box-shadow: 0 8px 28px rgba(31, 41, 55, 0.05);
  transition: transform 0.35s ease, border-color 0.35s ease, box-shadow 0.35s ease;
}

.flow-step:hover {
  transform: translateY(-8px);
  border-color: rgba(31, 41, 55, 0.3);
  box-shadow: var(--shadow-glow);
}

.flow-step .num {
  width: 46px;
  height: 46px;
  margin: 0 auto 18px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: var(--accent-gradient);
  color: #ffffff;
  font-size: 18px;
  font-weight: 700;
  box-shadow: 0 8px 24px rgba(31, 41, 55, 0.35);
}

.flow-step h3 {
  font-size: 18px;
  font-weight: 700;
  color: var(--text);
  margin: 0 0 10px;
}

.flow-step p {
  font-size: 14px;
  color: var(--text-muted);
  line-height: 1.7;
  margin: 0;
}

.flow-step:not(:last-child)::after {
  content: "";
  position: absolute;
  top: 50%;
  right: -22px;
  width: 22px;
  height: 2px;
  background: linear-gradient(90deg, rgba(31, 41, 55, 0.45), transparent);
  transform: translateY(-50%);
}

/* 滚动进场动画辅助类 */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}

.reveal.in {
  opacity: 1;
  transform: translateY(0);
}

/* 响应式 */
@media (max-width: 1024px) {
  .banner .center {
    flex-direction: column-reverse;
    text-align: center;
    gap: 50px;
  }
  .banner .center .left {
    text-align: center;
    max-width: 700px;
  }
  .banner .center .left .title {
    font-size: 44px;
  }
  .banner .center .left .desc {
    font-size: 18px;
    margin-left: auto;
    margin-right: auto;
  }
  .banner .center .left .actions {
    justify-content: center;
  }
  .hero-visual {
    max-width: 420px;
  }
  .hero-card.float-1 {
    right: -10px;
  }
  .hero-card.float-2 {
    right: -10px;
  }
  .adv-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .coverage-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .opt-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .service-flow {
    grid-template-columns: repeat(2, 1fr);
  }
  .flow-step:not(:last-child)::after {
    display: none;
  }
}

@media (max-width: 768px) {
  .banner {
    min-height: auto;
    padding: 130px 0 70px;
  }
  .banner .center .left .title {
    font-size: 34px;
  }
  .banner .center .left .desc {
    font-size: 16px;
  }
  .banner .center .left .btn,
  .banner .center .left .btn-outline {
    padding: 13px 26px;
    font-size: 15px;
  }
  .hero-visual {
    max-width: 90%;
  }
  .hero-card.float-1,
  .hero-card.float-2 {
    display: none;
  }
  .section-title {
    font-size: 28px;
  }
  .section-desc {
    font-size: 15px;
    margin-bottom: 36px;
  }
  .coverage-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }
  .coverage-card {
    padding: 24px 22px 22px;
    border-color: rgba(31, 41, 55, 0.18);
    box-shadow: 0 6px 20px rgba(31, 41, 55, 0.07);
  }
  .coverage-icon {
    width: 52px;
    height: 52px;
    margin-bottom: 16px;
  }
  .coverage-title {
    font-size: 18px;
    margin: 0 0 8px;
  }
  .coverage-desc {
    font-size: 13px;
    margin: 0 0 14px;
  }
  .adv-grid,
  .opt-grid,
  .service-flow {
    grid-template-columns: 1fr;
    max-width: 420px;
  }
  .opt-card .img-wrapper {
    height: 170px;
  }
}

@media (max-width: 480px) {
  .banner .center .left .title {
    font-size: 29px;
  }
  .banner .center .left .actions {
    flex-direction: column;
    width: 100%;
  }
  .banner .center .left .btn,
  .banner .center .left .btn-outline {
    width: 100%;
  }
  .coverage-grid {
    gap: 12px;
  }
  .coverage-card {
    padding: 20px 18px 18px;
  }
  .coverage-icon {
    width: 46px;
    height: 46px;
  }
  .rank-card {
    padding: 22px 20px;
  }
  .rank-list .rank-item {
    padding: 10px 12px;
    gap: 10px;
  }
  .rank-no {
    width: 24px;
    height: 24px;
    font-size: 12px;
  }
  .rank-kw {
    font-size: 14px;
  }
  .rank-pos {
    font-size: 12px;
    padding: 3px 10px;
  }
  .rank-stats strong {
    font-size: 20px;
  }
}