:root {
  --primary: #ff4d00;
  --primary-glow: #ff7a00;
  --secondary: #0052ff;
  --accent-cyan: #00e5ff;
  --accent-purple: #7000ff;
  --accent-yellow: #ffe600;
  --bg-page: #f6f8fc;
  --bg-card: #ffffff;
  --text-main: #141824;
  --text-muted: #5b6479;
  --text-light: #8a94a6;
  --border-color: #e5eaf2;
  --shadow-sm: 0 4px 12px rgba(20, 24, 36, 0.04);
  --shadow-md: 0 12px 32px rgba(20, 24, 36, 0.08);
  --shadow-lg: 0 20px 48px rgba(0, 82, 255, 0.12);
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-full: 9999px;
  --container-width: 1200px;
}

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

html {
  scroll-behavior: smooth;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--text-main);
  background-color: var(--bg-page);
  line-height: 1.6;
}

body {
  overflow-x: hidden;
  position: relative;
}

.container {
  max-width: var(--container-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: 20px;
  padding-right: 20px;
  width: 100%;
}

a {
  color: inherit;
  text-decoration: none;
  transition: all 0.25s ease;
}

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

.section {
  padding: 80px 0;
  position: relative;
}

.section-header {
  text-align: center;
  margin-bottom: 50px;
}

.section-tag {
  display: inline-block;
  padding: 6px 16px;
  font-size: 13px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  border-radius: var(--radius-full);
  background: linear-gradient(135deg, rgba(255, 77, 0, 0.12), rgba(0, 82, 255, 0.12));
  color: var(--primary);
  border: 1px solid rgba(255, 77, 0, 0.2);
  margin-bottom: 14px;
}

.section-title {
  font-size: 32px;
  font-weight: 800;
  color: var(--text-main);
  line-height: 1.3;
  margin-bottom: 12px;
}

.section-desc {
  font-size: 16px;
  color: var(--text-muted);
  max-width: 680px;
  margin: 0 auto;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 28px;
  font-size: 15px;
  font-weight: 700;
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
  border: none;
  gap: 8px;
}

.btn:hover {
  transform: translateY(-2px);
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary), var(--primary-glow));
  color: #ffffff;
  box-shadow: 0 8px 24px rgba(255, 77, 0, 0.35);
}

.btn-primary:hover {
  box-shadow: 0 12px 30px rgba(255, 77, 0, 0.45);
}

.btn-secondary {
  background: linear-gradient(135deg, var(--secondary), var(--accent-purple));
  color: #ffffff;
  box-shadow: 0 8px 24px rgba(0, 82, 255, 0.3);
}

.btn-secondary:hover {
  box-shadow: 0 12px 30px rgba(0, 82, 255, 0.4);
}

.btn-outline {
  background: #ffffff;
  color: var(--text-main);
  border: 2px solid var(--border-color);
}

.btn-outline:hover {
  border-color: var(--primary);
  color: var(--primary);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
}

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

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

.ai-page-logo {
  max-height: 40px;
  width: auto;
}

.brand-title {
  font-size: 20px;
  font-weight: 800;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
  -webkit-background-clip: text;
  color: transparent;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 0;
  list-style: none;
}

.nav-links li a {
  padding: 8px 14px;
  font-size: 14px;
  font-weight: 600;
  color: var(--text-muted);
  border-radius: var(--radius-sm);
  display: block;
}

.nav-links li a:hover,
.nav-links li a.active {
  color: var(--primary);
  background: rgba(255, 77, 0, 0.06);
}

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

.mobile-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 24px;
  color: var(--text-main);
  cursor: pointer;
  padding: 6px;
}

.hero-section {
  padding: 90px 0 70px;
  background: radial-gradient(circle at 80% 20%, rgba(255, 77, 0, 0.12) 0%, rgba(246, 248, 252, 0) 50%),
              radial-gradient(circle at 10% 80%, rgba(0, 82, 255, 0.12) 0%, rgba(246, 248, 252, 0) 50%),
              var(--bg-page);
  position: relative;
}

.hero-wrapper {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 40px;
  align-items: center;
}

.hero-content {
  text-align: left;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: #ffffff;
  border: 1px solid var(--border-color);
  padding: 6px 16px;
  border-radius: var(--radius-full);
  font-size: 13px;
  font-weight: 700;
  color: var(--secondary);
  box-shadow: var(--shadow-sm);
  margin-bottom: 20px;
}

.hero-badge .dot {
  width: 8px;
  height: 8px;
  background: var(--primary);
  border-radius: 50%;
  animation: pulse 1.8s infinite;
}

@keyframes pulse {
  0% { transform: scale(0.9); opacity: 0.8; }
  50% { transform: scale(1.3); opacity: 1; box-shadow: 0 0 10px var(--primary); }
  100% { transform: scale(0.9); opacity: 0.8; }
}

.hero-title {
  font-size: 42px;
  font-weight: 900;
  line-height: 1.25;
  color: var(--text-main);
  margin-bottom: 18px;
}

.hero-title .highlight {
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent-purple) 100%);
  -webkit-background-clip: text;
  color: transparent;
}

.hero-subtitle {
  font-size: 17px;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 32px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-bottom: 36px;
}

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

.hero-tag-item {
  background: #ffffff;
  border: 1px solid var(--border-color);
  padding: 4px 12px;
  border-radius: var(--radius-sm);
  font-size: 12px;
  font-weight: 600;
  color: var(--text-muted);
}

.hero-card-board {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}

.hero-stat-card {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 24px 20px;
  box-shadow: var(--shadow-sm);
  transition: transform 0.25s ease, box-shadow 0.25s ease;
  position: relative;
  overflow: hidden;
}

.hero-stat-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: var(--primary);
}

.hero-stat-card:nth-child(2)::before { background: var(--secondary); }
.hero-stat-card:nth-child(3)::before { background: var(--accent-cyan); }
.hero-stat-card:nth-child(4)::before { background: var(--accent-purple); }

.hero-stat-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.stat-icon {
  font-size: 24px;
  margin-bottom: 8px;
}

.stat-num {
  font-size: 28px;
  font-weight: 800;
  color: var(--text-main);
  line-height: 1.1;
  margin-bottom: 4px;
}

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

.model-strip {
  padding: 24px 0;
  background: #ffffff;
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
  overflow: hidden;
}

.model-strip-title {
  text-align: center;
  font-size: 13px;
  font-weight: 700;
  color: var(--text-light);
  text-transform: uppercase;
  margin-bottom: 14px;
  letter-spacing: 1px;
}

.model-tags-wrap {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
}

.model-pill {
  background: var(--bg-page);
  border: 1px solid var(--border-color);
  padding: 6px 14px;
  border-radius: var(--radius-full);
  font-size: 12px;
  font-weight: 700;
  color: var(--text-muted);
  transition: all 0.2s ease;
}

.model-pill:hover {
  background: var(--text-main);
  color: #ffffff;
  transform: translateY(-2px);
}

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

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

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

.card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 28px;
  box-shadow: var(--shadow-sm);
  transition: all 0.25s ease;
  position: relative;
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: rgba(255, 77, 0, 0.3);
}

.card-icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  margin-bottom: 18px;
  background: linear-gradient(135deg, rgba(255, 77, 0, 0.1), rgba(0, 82, 255, 0.1));
  color: var(--primary);
}

.card-title {
  font-size: 18px;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 10px;
}

.card-text {
  font-size: 14px;
  color: var(--text-muted);
  line-height: 1.6;
}

.card-tag {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 11px;
  font-weight: 700;
  background: rgba(0, 82, 255, 0.1);
  color: var(--secondary);
  margin-bottom: 10px;
}

.contrast-badge {
  background: #ffffff;
  border: 2px solid var(--primary);
  border-radius: var(--radius-lg);
  padding: 30px;
  margin-bottom: 30px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 20px;
  box-shadow: var(--shadow-md);
}

.contrast-badge .score-box {
  display: flex;
  align-items: center;
  gap: 16px;
}

.big-score {
  font-size: 48px;
  font-weight: 900;
  color: var(--primary);
  line-height: 1;
}

.stars {
  color: #ffaa00;
  font-size: 20px;
  margin-bottom: 4px;
}

.table-responsive {
  width: 100%;
  overflow-x: auto;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  background: #ffffff;
  box-shadow: var(--shadow-sm);
}

.eval-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  min-width: 640px;
}

.eval-table th,
.eval-table td {
  padding: 16px 20px;
  border-bottom: 1px solid var(--border-color);
  font-size: 14px;
}

.eval-table th {
  background: #fbfcfd;
  font-weight: 700;
  color: var(--text-main);
}

.eval-table tr:hover {
  background: rgba(0, 82, 255, 0.02);
}

.eval-table .highlight-col {
  background: rgba(255, 77, 0, 0.04);
  font-weight: 700;
  color: var(--primary);
}

.step-card {
  text-align: center;
  padding: 30px 20px;
  background: #ffffff;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  position: relative;
}

.step-num {
  width: 44px;
  height: 44px;
  background: linear-gradient(135deg, var(--secondary), var(--accent-cyan));
  color: #ffffff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  font-weight: 800;
  margin: 0 auto 16px;
}

.case-card {
  background: #ffffff;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.case-img-wrap {
  position: relative;
  overflow: hidden;
  background: #eef2f7;
}

.case-img-wrap img {
  width: 100%;
  transition: transform 0.3s ease;
}

.case-card:hover .case-img-wrap img {
  transform: scale(1.04);
}

.case-body {
  padding: 20px;
}

.faq-container {
  max-width: 860px;
  margin: 0 auto;
}

.faq-item {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  margin-bottom: 12px;
  overflow: hidden;
  transition: all 0.2s ease;
}

.faq-question {
  padding: 18px 24px;
  font-size: 16px;
  font-weight: 700;
  color: var(--text-main);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  user-select: none;
}

.faq-question:hover {
  color: var(--primary);
}

.faq-icon {
  font-size: 18px;
  transition: transform 0.25s ease;
  color: var(--text-muted);
}

.faq-item.active .faq-icon {
  transform: rotate(45deg);
  color: var(--primary);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s cubic-bezier(0.4, 0, 0.2, 1), padding 0.3s ease;
  padding: 0 24px;
  color: var(--text-muted);
  font-size: 14px;
  line-height: 1.7;
}

.faq-item.active .faq-answer {
  max-height: 250px;
  padding: 0 24px 20px;
}

.review-card {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 24px;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.review-user {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
}

.avatar-badge {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: #ffffff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 16px;
}

.user-meta h4 {
  font-size: 15px;
  font-weight: 700;
  color: var(--text-main);
}

.user-meta p {
  font-size: 12px;
  color: var(--text-light);
}

.review-text {
  font-size: 14px;
  color: var(--text-muted);
  line-height: 1.6;
}

.form-wrapper {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 36px;
  box-shadow: var(--shadow-md);
}

.form-group {
  margin-bottom: 20px;
}

.form-label {
  display: block;
  font-size: 14px;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--text-main);
}

.form-control {
  width: 100%;
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
  background: #fbfcfd;
  font-size: 14px;
  color: var(--text-main);
  outline: none;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.form-control:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(255, 77, 0, 0.15);
  background: #ffffff;
}

textarea.form-control {
  min-height: 110px;
  resize: vertical;
}

.contact-info-list {
  list-style: none;
  margin-top: 24px;
}

.contact-info-item {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  margin-bottom: 16px;
  font-size: 14px;
  color: var(--text-muted);
}

.contact-icon {
  font-size: 18px;
  color: var(--primary);
}

.qr-box {
  margin-top: 24px;
  padding: 16px;
  background: #fbfcfd;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  text-align: center;
  max-width: 220px;
}

.qr-box img {
  border-radius: 8px;
  margin: 0 auto 10px;
  width: 140px;
  height: 140px;
  object-fit: cover;
}

.article-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.article-item {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 16px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  transition: all 0.2s ease;
}

.article-item:hover {
  border-color: var(--primary);
  background: rgba(255, 77, 0, 0.02);
}

.article-title {
  font-size: 15px;
  font-weight: 600;
  color: var(--text-main);
}

.article-link-tag {
  font-size: 13px;
  color: var(--secondary);
  font-weight: 700;
}

.footer {
  background: #ffffff;
  border-top: 1px solid var(--border-color);
  padding: 50px 0 30px;
}

.footer-top {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.5fr;
  gap: 40px;
  margin-bottom: 40px;
}

.footer-col h4 {
  font-size: 16px;
  font-weight: 800;
  margin-bottom: 16px;
  color: var(--text-main);
}

.footer-links {
  list-style: none;
}

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

.footer-links a {
  font-size: 14px;
  color: var(--text-muted);
}

.footer-links a:hover {
  color: var(--primary);
}

.friend-links-area {
  padding: 24px 0;
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
  margin-bottom: 24px;
}

.friend-links-title {
  font-size: 14px;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 12px;
}

.friend-links-wrap {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
}

.friend-links-wrap a {
  font-size: 13px;
  color: var(--text-muted);
  background: var(--bg-page);
  padding: 6px 14px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
}

.friend-links-wrap a:hover {
  color: var(--primary);
  border-color: var(--primary);
}

.footer-bottom {
  text-align: center;
  font-size: 13px;
  color: var(--text-light);
}

.float-kefu {
  position: fixed;
  right: 20px;
  bottom: 30px;
  z-index: 999;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.float-btn {
  width: 50px;
  height: 50px;
  border-radius: 50%;
  background: var(--primary);
  color: #ffffff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  box-shadow: var(--shadow-lg);
  cursor: pointer;
  border: none;
  transition: all 0.25s ease;
  position: relative;
}

.float-btn:hover {
  transform: scale(1.08);
}

.float-card-pop {
  position: absolute;
  right: 60px;
  bottom: 0;
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 16px;
  box-shadow: var(--shadow-lg);
  display: none;
  width: 180px;
  text-align: center;
}

.float-btn:hover .float-card-pop {
  display: block;
}

@media (max-width: 992px) {
  .hero-wrapper {
    grid-template-columns: 1fr;
    gap: 32px;
  }
  .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }
  .grid-3 {
    grid-template-columns: repeat(2, 1fr);
  }
  .footer-top {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .section {
    padding: 50px 0;
  }
  .hero-title {
    font-size: 28px;
  }
  .grid-4, .grid-3, .grid-2 {
    grid-template-columns: 1fr;
  }
  .mobile-toggle {
    display: block;
  }
  .nav-links {
    position: absolute;
    top: 72px;
    left: 0;
    width: 100%;
    background: #ffffff;
    flex-direction: column;
    align-items: stretch;
    padding: 20px;
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--shadow-md);
    display: none;
  }
  .nav-links.show {
    display: flex;
  }
  .nav-cta {
    display: none;
  }
  .footer-top {
    grid-template-columns: 1fr;
  }
}