:root {
  --primary: #ff3366;
  --primary-hover: #e02456;
  --secondary: #6366f1;
  --accent: #00d2ff;
  --dark: #0f172a;
  --text-main: #1e293b;
  --text-muted: #64748b;
  --bg-page: #f8fafc;
  --bg-card: #ffffff;
  --border: #e2e8f0;
  --gradient-trend: linear-gradient(135deg, #ff3366 0%, #ff6b4a 50%, #6366f1 100%);
  --gradient-subtle: linear-gradient(180deg, #fff0f3 0%, #f8fafc 100%);
  --shadow-sm: 0 2px 4px rgba(0,0,0,0.04);
  --shadow-md: 0 10px 25px -5px rgba(255, 51, 102, 0.08), 0 8px 10px -6px rgba(0,0,0,0.04);
  --shadow-lg: 0 20px 30px -10px rgba(99, 102, 241, 0.15);
  --radius: 12px;
}

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

html {
  scroll-behavior: smooth;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  color: var(--text-main);
  background-color: var(--bg-page);
  line-height: 1.6;
}

body {
  width: 100%;
  overflow-x: hidden;
  background-color: var(--bg-page);
}

.ai-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
  width: 100%;
}

header.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}

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

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

.brand-logo {
  height: 40px;
  display: flex;
  align-items: center;
}

.brand-logo img {
  height: 36px;
  width: auto;
  max-width: 100%;
}

.brand-title {
  font-size: 1.25rem;
  font-weight: 800;
  background: var(--gradient-trend);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  text-decoration: none;
}

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

.nav-links li a {
  padding: 8px 12px;
  font-size: 0.95rem;
  color: var(--text-main);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.2s ease;
  border-radius: 6px;
}

.nav-links li a:hover {
  color: var(--primary);
  background-color: #fff0f3;
}

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

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 24px;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: 30px;
  text-decoration: none;
  cursor: pointer;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  border: 1px solid transparent;
}

.btn-primary {
  background: var(--gradient-trend);
  color: #ffffff !important;
  box-shadow: 0 4px 14px rgba(255, 51, 102, 0.3);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(255, 51, 102, 0.4);
}

.btn-secondary {
  background: #ffffff;
  color: var(--text-main);
  border-color: var(--border);
}

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

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

.btn-outline:hover {
  background: #fff0f3;
}

.hero-section {
  position: relative;
  padding: 80px 0 60px;
  background: var(--gradient-subtle);
  border-bottom: 1px solid rgba(255, 51, 102, 0.1);
  text-align: center;
}

.hero-tag {
  display: inline-flex;
  align-items: center;
  padding: 6px 16px;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--primary);
  background: #ffffff;
  border: 1px solid rgba(255, 51, 102, 0.2);
  border-radius: 20px;
  margin-bottom: 20px;
  box-shadow: var(--shadow-sm);
}

.hero-h1 {
  font-size: 2.75rem;
  font-weight: 900;
  line-height: 1.25;
  color: var(--dark);
  margin-bottom: 20px;
  letter-spacing: -0.5px;
}

.hero-h1 span {
  background: var(--gradient-trend);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-desc {
  max-width: 760px;
  margin: 0 auto 36px;
  font-size: 1.15rem;
  color: var(--text-muted);
}

.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 48px;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  max-width: 1000px;
  margin: 0 auto;
}

.stat-card {
  background: #ffffff;
  border: 1px solid var(--border);
  padding: 20px;
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s ease;
}

.stat-card:hover {
  transform: translateY(-4px);
  border-color: var(--primary);
}

.stat-number {
  font-size: 2rem;
  font-weight: 800;
  color: var(--primary);
  margin-bottom: 4px;
}

.stat-label {
  font-size: 0.875rem;
  color: var(--text-muted);
  font-weight: 500;
}

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

.section-block.bg-alt {
  background-color: #ffffff;
}

.section-header {
  text-align: center;
  max-width: 760px;
  margin: 0 auto 50px;
}

.section-title {
  font-size: 2rem;
  font-weight: 800;
  color: var(--dark);
  margin-bottom: 12px;
}

.section-subtitle {
  font-size: 1rem;
  color: var(--text-muted);
}

.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: 32px;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  transition: all 0.3s ease;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: rgba(255, 51, 102, 0.4);
}

.card-icon {
  width: 48px;
  height: 48px;
  border-radius: 10px;
  background: #fff0f3;
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  font-weight: bold;
  margin-bottom: 18px;
}

.card-title {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--dark);
  margin-bottom: 10px;
}

.card-text {
  font-size: 0.925rem;
  color: var(--text-muted);
  line-height: 1.6;
}

.tag-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
  margin-top: 30px;
}

.tag-item {
  background: #ffffff;
  border: 1px solid var(--border);
  padding: 6px 14px;
  border-radius: 20px;
  font-size: 0.875rem;
  color: var(--text-main);
  font-weight: 500;
  transition: all 0.2s ease;
}

.tag-item:hover {
  background: var(--primary);
  color: #ffffff;
  border-color: var(--primary);
}

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

.step-item {
  background: #ffffff;
  padding: 24px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  position: relative;
}

.step-badge {
  display: inline-block;
  padding: 4px 10px;
  font-size: 0.75rem;
  font-weight: 700;
  color: #ffffff;
  background: var(--secondary);
  border-radius: 6px;
  margin-bottom: 12px;
}

.eval-container {
  background: #ffffff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  box-shadow: var(--shadow-sm);
}

.eval-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--border);
  padding-bottom: 24px;
  margin-bottom: 24px;
  flex-wrap: wrap;
  gap: 16px;
}

.eval-score {
  display: flex;
  align-items: center;
  gap: 16px;
}

.score-num {
  font-size: 3rem;
  font-weight: 900;
  color: var(--primary);
  line-height: 1;
}

.score-meta {
  display: flex;
  flex-direction: column;
}

.stars {
  color: #ffb800;
  font-size: 1.25rem;
  letter-spacing: 2px;
}

.eval-table-wrapper {
  overflow-x: auto;
}

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

.eval-table th, .eval-table td {
  padding: 14px 16px;
  border-bottom: 1px solid var(--border);
  font-size: 0.925rem;
}

.eval-table th {
  background: #f8fafc;
  font-weight: 600;
  color: var(--dark);
}

.eval-table tr:hover td {
  background: #fff0f3;
}

.badge-highlight {
  display: inline-block;
  background: rgba(255, 51, 102, 0.1);
  color: var(--primary);
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 0.8rem;
}

.faq-list {
  display: flex;
  flex-direction: column;
  gap: 14px;
  max-width: 900px;
  margin: 0 auto;
}

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

.faq-question {
  padding: 20px;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: var(--dark);
  user-select: none;
}

.faq-toggle {
  font-size: 1.2rem;
  color: var(--primary);
  transition: transform 0.3s ease;
}

.faq-answer {
  padding: 0 20px 20px;
  color: var(--text-muted);
  font-size: 0.925rem;
  display: none;
  line-height: 1.6;
  border-top: 1px solid #f1f5f9;
  margin-top: -6px;
  padding-top: 14px;
}

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

.faq-item.active .faq-toggle {
  transform: rotate(45deg);
}

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

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

.review-author {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-top: 16px;
  padding-top: 16px;
  border-top: 1px solid var(--border);
}

.avatar-placeholder {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: var(--gradient-trend);
  color: #ffffff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1rem;
}

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

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

.form-label {
  display: block;
  font-weight: 600;
  margin-bottom: 8px;
  font-size: 0.9rem;
  color: var(--dark);
}

.form-input, .form-select, .form-textarea {
  width: 100%;
  padding: 12px 16px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 0.95rem;
  color: var(--text-main);
  background: #ffffff;
  outline: none;
  transition: border-color 0.2s;
}

.form-input:focus, .form-select:focus, .form-textarea:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(255, 51, 102, 0.1);
}

.form-textarea {
  min-height: 120px;
  resize: vertical;
}

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

.article-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 18px;
  background: #ffffff;
  border: 1px solid var(--border);
  border-radius: 8px;
  text-decoration: none;
  color: var(--text-main);
  font-weight: 500;
  transition: all 0.2s ease;
}

.article-link:hover {
  border-color: var(--primary);
  color: var(--primary);
  transform: translateX(4px);
}

.img-container {
  width: 100%;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
  background: #ffffff;
}

.img-container img {
  width: 100%;
  height: auto;
  display: block;
  object-fit: contain;
}

.footer-section {
  background: #ffffff;
  border-top: 1px solid var(--border);
  padding: 60px 0 24px;
}

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

.footer-col-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--dark);
  margin-bottom: 16px;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-links li a {
  text-decoration: none;
  color: var(--text-muted);
  font-size: 0.9rem;
  transition: color 0.2s;
}

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

.qr-card {
  display: flex;
  align-items: center;
  gap: 16px;
  background: #f8fafc;
  padding: 14px;
  border-radius: 8px;
  border: 1px solid var(--border);
}

.qr-card img {
  width: 80px;
  height: 80px;
  border-radius: 4px;
  border: 1px solid var(--border);
}

.qr-info {
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.4;
}

.friend-links-bar {
  border-top: 1px solid var(--border);
  padding: 20px 0;
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  font-size: 0.85rem;
}

.friend-links-bar a {
  color: var(--text-muted);
  text-decoration: none;
}

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

.footer-bottom {
  border-top: 1px solid var(--border);
  padding-top: 20px;
  text-align: center;
  font-size: 0.85rem;
  color: var(--text-muted);
}

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

.float-btn {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: #ffffff;
  box-shadow: 0 4px 12px rgba(0,0,0,0.15);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--primary);
  text-decoration: none;
  border: 1px solid var(--border);
  cursor: pointer;
  transition: all 0.2s ease;
  font-size: 1.2rem;
}

.float-btn:hover {
  background: var(--primary);
  color: #ffffff;
  transform: scale(1.05);
}

.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  color: var(--dark);
  cursor: pointer;
}

@media (max-width: 992px) {
  .hero-stats { grid-template-columns: repeat(2, 1fr); }
  .grid-3, .review-grid { grid-template-columns: repeat(2, 1fr); }
  .grid-4, .step-timeline { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
  .mobile-menu-btn { display: block; }
  .nav-links {
    display: none;
    position: absolute;
    top: 72px;
    left: 0;
    width: 100%;
    background: #ffffff;
    flex-direction: column;
    padding: 20px;
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow-md);
  }
  .nav-links.show { display: flex; }
  .nav-links li { width: 100%; text-align: center; }
  .nav-links li a { display: block; padding: 10px; }
  .hero-h1 { font-size: 2rem; }
  .grid-2, .grid-3, .grid-4, .review-grid, .hero-stats, .step-timeline { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .eval-top { flex-direction: column; align-items: flex-start; }
}