/* ========================================
   AI生意经 - Global Stylesheet (Premium Light Theme)
   Design: Elegant White + Tech Accents
======================================== */

:root {
  --bg-dark: #f8fafc;
  --bg-card: #ffffff;
  --bg-card-hover: #ffffff;
  --border: rgba(15, 23, 42, 0.06);
  --border-hover: rgba(15, 23, 42, 0.12);
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #64748b;
  --accent-gold: #e2a400; /* 调深以适应浅色底 */
  --accent-gold-light: #fef08a;
  --accent-emerald: #059669;
  --accent-blue: #2563eb;
  --accent-purple: #7c3aed;
  --accent-pink: #db2777;
  --gradient-hero: linear-gradient(135deg, #eff6ff 0%, #f8fafc 40%, #f0fdf4 100%);
  --gradient-gold: linear-gradient(135deg, #e2a400, #ea580c);
  --gradient-card: linear-gradient(145deg, #ffffff, #fdfdfd);
  --shadow-card: 0 10px 30px -10px rgba(0, 0, 0, 0.04), 0 1px 3px rgba(0, 0, 0, 0.02);
  --shadow-hover: 0 20px 40px -15px rgba(0, 0, 0, 0.08), 0 1px 5px rgba(0, 0, 0, 0.03);
  --radius: 16px;
  --radius-sm: 10px;
  --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html { scroll-behavior: smooth; }

body {
  font-family: 'Noto Sans SC', 'Inter', -apple-system, sans-serif;
  background: var(--bg-dark);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* =========== HEADER =========== */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
  transition: var(--transition);
}

.site-header .container {
  display: flex;
  align-items: center;
  gap: 32px;
  height: 68px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  flex-shrink: 0;
}

.logo-icon { font-size: 24px; }

.logo-text {
  font-size: 20px;
  font-weight: 800;
  color: var(--text-primary);
  letter-spacing: -0.5px;
}

.logo-accent {
  background: var(--gradient-gold);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 4px;
  flex: 1;
}

.nav-link {
  padding: 8px 16px;
  border-radius: 8px;
  text-decoration: none;
  color: var(--text-secondary);
  font-size: 14px;
  font-weight: 500;
  transition: var(--transition);
}

.nav-link:hover {
  color: var(--text-primary);
  background: rgba(0,0,0,0.04);
}

.header-actions { margin-left: auto; }

.btn-subscribe {
  background: var(--gradient-gold);
  border: none;
  border-radius: 10px;
  padding: 10px 20px;
  color: #ffffff;
  font-weight: 700;
  font-size: 14px;
  cursor: pointer;
  transition: var(--transition);
  font-family: inherit;
  box-shadow: 0 4px 12px rgba(226, 164, 0, 0.2);
}

.btn-subscribe:hover { opacity: 0.9; transform: translateY(-1px); box-shadow: 0 6px 16px rgba(226, 164, 0, 0.3); }

.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  color: var(--text-primary);
  font-size: 22px;
  cursor: pointer;
  margin-left: auto;
}

/* =========== HERO =========== */
.hero {
  position: relative;
  min-height: 85vh;
  display: flex;
  align-items: center;
  padding: 120px 0 80px;
  background: var(--gradient-hero);
  overflow: hidden;
}

.hero-bg-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(15, 23, 42, 0.02) 1px, transparent 1px),
    linear-gradient(90deg, rgba(15, 23, 42, 0.02) 1px, transparent 1px);
  background-size: 60px 60px;
}

.hero::after {
  content: '';
  position: absolute;
  top: 20%;
  right: -10%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(96,165,250,0.08) 0%, transparent 70%);
  pointer-events: none;
}

.hero .container { position: relative; z-index: 1; }

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(226, 164, 0, 0.08);
  border: 1px solid rgba(226, 164, 0, 0.15);
  color: var(--accent-gold);
  padding: 8px 16px;
  border-radius: 100px;
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 28px;
  animation: fadeInDown 0.6s ease;
}

.badge-dot {
  width: 8px; height: 8px;
  background: var(--accent-gold);
  border-radius: 50%;
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(0.8); }
}

.hero-title {
  font-size: clamp(38px, 5.5vw, 64px);
  font-weight: 900;
  line-height: 1.2;
  letter-spacing: -1.5px;
  margin-bottom: 24px;
  color: #0f172a;
  animation: fadeInUp 0.7s ease 0.1s both;
}

.gradient-text {
  background: var(--gradient-gold);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-subtitle {
  font-size: 18px;
  color: var(--text-secondary);
  max-width: 650px;
  margin-bottom: 40px;
  line-height: 1.8;
  animation: fadeInUp 0.7s ease 0.2s both;
}

.hero-subtitle strong { color: var(--text-primary); }

.hero-stats {
  display: flex;
  align-items: center;
  gap: 32px;
  margin-bottom: 40px;
  flex-wrap: wrap;
  animation: fadeInUp 0.7s ease 0.3s both;
}

.stat-item { text-align: center; }

.stat-number {
  display: block;
  font-size: 28px;
  font-weight: 800;
  color: var(--text-primary);
  line-height: 1;
  font-variant-numeric: tabular-nums;
}

.stat-label {
  font-size: 12px;
  color: var(--text-muted);
  margin-top: 4px;
}

.stat-divider {
  width: 1px;
  height: 40px;
  background: var(--border);
}

.hero-search {
  margin-bottom: 20px;
  animation: fadeInUp 0.7s ease 0.4s both;
}

.search-box {
  display: flex;
  align-items: center;
  gap: 12px;
  background: #ffffff;
  border: 1px solid rgba(15, 23, 42, 0.1);
  border-radius: 14px;
  padding: 14px 20px;
  max-width: 620px;
  transition: var(--transition);
  box-shadow: 0 4px 20px -2px rgba(0,0,0,0.03);
}

.search-box:focus-within {
  border-color: var(--accent-blue);
  background: #ffffff;
  box-shadow: 0 0 0 3px rgba(37,99,235,0.08);
}

.search-icon { font-size: 18px; flex-shrink: 0; }

.search-box input {
  flex: 1;
  background: none;
  border: none;
  outline: none;
  color: var(--text-primary);
  font-size: 16px;
  font-family: inherit;
}

.search-box input::placeholder { color: var(--text-muted); }

.hero-tags {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
  animation: fadeInUp 0.7s ease 0.5s both;
}

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

.filter-tag {
  background: #ffffff;
  border: 1px solid var(--border);
  color: var(--text-secondary);
  padding: 6px 14px;
  border-radius: 100px;
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
  font-family: inherit;
  box-shadow: 0 2px 5px rgba(0,0,0,0.02);
}

.filter-tag:hover,
.filter-tag.active {
  background: rgba(37,99,235,0.05);
  border-color: var(--accent-blue);
  color: var(--accent-blue);
}

/* =========== SECTIONS =========== */
.section-header {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  margin-bottom: 32px;
  gap: 16px;
  flex-wrap: wrap;
}

.section-title {
  font-size: 28px;
  font-weight: 800;
  letter-spacing: -0.5px;
  color: #0f172a;
}

.section-subtitle {
  color: var(--text-secondary);
  font-size: 15px;
}

/* =========== FEATURED SECTION =========== */
.featured-section {
  padding: 80px 0;
}

.featured-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 24px;
}

/* =========== PROJECT CARD =========== */
.project-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  cursor: pointer;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-card);
}

.project-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 4px;
  background: var(--card-color, var(--accent-gold));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s ease;
}

.project-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
}

.project-card:hover::before { transform: scaleX(1); }

.card-header {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 16px;
}

.card-emoji {
  width: 52px; height: 52px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 26px;
  flex-shrink: 0;
  background: var(--emoji-bg, rgba(226, 164, 0, 0.08));
}

.card-title-group { flex: 1; min-width: 0; }

.card-name {
  font-size: 17px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 4px;
  line-height: 1.3;
}

.card-name-en {
  font-size: 12px;
  color: var(--text-muted);
}

.card-tags {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
  margin-bottom: 14px;
}

.card-tag {
  background: #f1f5f9;
  border: 1px solid rgba(15, 23, 42, 0.05);
  color: var(--text-secondary);
  font-size: 11px;
  padding: 3px 8px;
  border-radius: 6px;
  font-weight: 500;
}

.card-summary {
  color: var(--text-secondary);
  font-size: 14px;
  line-height: 1.7;
  margin-bottom: 20px;
}

.card-metrics {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  padding-top: 18px;
  border-top: 1px solid var(--border);
}

.metric-item { text-align: center; }

.metric-value {
  font-size: 18px;
  font-weight: 800;
  color: var(--accent-emerald);
  display: block;
  line-height: 1;
  margin-bottom: 3px;
}

.metric-value.gold { color: var(--accent-gold); }
.metric-value.blue { color: var(--accent-blue); }

.metric-label {
  font-size: 11px;
  color: var(--text-muted);
}

.card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 18px;
}

.score-badge {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  color: var(--text-secondary);
}

.score-stars { color: var(--accent-gold); letter-spacing: -2px; }

.card-arrow {
  width: 34px; height: 34px;
  border-radius: 10px;
  background: #f1f5f9;
  border: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  transition: var(--transition);
}

.project-card:hover .card-arrow {
  background: var(--accent-blue);
  border-color: var(--accent-blue);
  color: #ffffff;
}

/* Featured badge */
.featured-badge {
  position: absolute;
  top: 20px; right: 20px;
  background: var(--gradient-gold);
  color: #ffffff;
  font-size: 10px;
  font-weight: 800;
  padding: 4px 10px;
  border-radius: 100px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

/* =========== ALL PROJECTS =========== */
.all-projects-section {
  padding: 0 0 80px;
}

.sort-controls { display: flex; gap: 12px; }

.sort-select {
  background: #ffffff;
  border: 1px solid var(--border);
  color: var(--text-primary);
  padding: 8px 16px;
  border-radius: 10px;
  font-size: 13px;
  font-family: inherit;
  cursor: pointer;
  outline: none;
  transition: var(--transition);
  box-shadow: 0 2px 5px rgba(0,0,0,0.02);
}

.sort-select:hover { border-color: var(--border-hover); }

.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 20px;
}

.empty-state {
  text-align: center;
  padding: 80px 0;
  color: var(--text-muted);
  font-size: 16px;
}

/* =========== CATEGORIES =========== */
.categories-section {
  padding: 80px 0;
  background: linear-gradient(180deg, transparent, rgba(96,165,250,0.02), transparent);
}

.categories-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

.category-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 24px 20px;
  text-align: center;
  cursor: pointer;
  transition: var(--transition);
  text-decoration: none;
  box-shadow: var(--shadow-card);
}

.category-card:hover {
  border-color: var(--accent-blue);
  background: rgba(37,99,235,0.03);
  transform: translateY(-2px);
}

.category-icon { font-size: 32px; margin-bottom: 10px; }
.category-name {
  font-size: 15px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 4px;
}
.category-count { font-size: 12px; color: var(--text-muted); }

/* =========== RADAR SECTION =========== */
.radar-section {
  padding: 100px 0;
  overflow: hidden;
}

.radar-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 80px;
  align-items: center;
}

.radar-badge {
  display: inline-block;
  background: rgba(5,150,105,0.08);
  border: 1px solid rgba(5,150,105,0.15);
  color: var(--accent-emerald);
  padding: 6px 14px;
  border-radius: 100px;
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 20px;
}

.radar-title {
  font-size: 36px;
  font-weight: 900;
  line-height: 1.25;
  letter-spacing: -1px;
  margin-bottom: 20px;
  color: #0f172a;
}

.radar-desc {
  color: var(--text-secondary);
  font-size: 16px;
  line-height: 1.8;
  margin-bottom: 28px;
}

.radar-features { margin-bottom: 36px; }

.radar-feature {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 12px;
  font-size: 15px;
  color: var(--text-secondary);
}

.feature-icon { font-size: 18px; }

.btn-radar {
  background: var(--gradient-gold);
  border: none;
  border-radius: 12px;
  padding: 14px 28px;
  color: #ffffff;
  font-weight: 800;
  font-size: 16px;
  cursor: pointer;
  transition: var(--transition);
  font-family: inherit;
  box-shadow: 0 4px 15px rgba(226, 164, 0, 0.25);
}

.btn-radar:hover { opacity: 0.9; transform: translateY(-2px); box-shadow: 0 8px 24px rgba(226, 164, 0, 0.35); }

/* Radar Visual */
.radar-visual {
  position: relative;
  width: 360px;
  height: 360px;
  margin: 0 auto;
}

.radar-ring {
  position: absolute;
  border: 1px solid rgba(5,150,105,0.1);
  border-radius: 50%;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
}

.ring-1 { width: 100%; height: 100%; animation: radarSpin 8s linear infinite; }
.ring-2 { width: 70%; height: 70%; animation: radarSpin 5s linear infinite reverse; }
.ring-3 { width: 40%; height: 40%; animation: radarSpin 3s linear infinite; }

@keyframes radarSpin {
  from { transform: translate(-50%, -50%) rotate(0deg); }
  to { transform: translate(-50%, -50%) rotate(360deg); }
}

.radar-dot {
  position: absolute;
  top: 50%; left: 50%;
  width: 12px; height: 12px;
  background: var(--accent-emerald);
  border-radius: 50%;
  transform: translate(-50%, -50%);
  box-shadow: 0 0 20px var(--accent-emerald);
  animation: pulse 2s infinite;
}

.radar-ping {
  position: absolute;
  background: var(--bg-card);
  border: 1px solid rgba(5,150,105,0.3);
  color: var(--text-primary);
  font-size: 11px;
  padding: 6px 12px;
  border-radius: 100px;
  white-space: nowrap;
  box-shadow: var(--shadow-card);
  animation: pingFloat 4s ease-in-out infinite;
}

.ping-1 { top: 10%; left: 5%; animation-delay: 0s; }
.ping-2 { top: 20%; right: -5%; animation-delay: 1s; }
.ping-3 { bottom: 20%; left: 0%; animation-delay: 2s; }
.ping-4 { bottom: 10%; right: 5%; animation-delay: 3s; }

@keyframes pingFloat {
  0%, 100% { transform: translateY(0); opacity: 0.8; }
  50% { transform: translateY(-6px); opacity: 1; }
}

/* =========== WECHAT SECTION =========== */
.wechat-section {
  padding: 80px 0;
}

.wechat-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 24px;
  padding: 60px;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 60px;
  align-items: center;
  box-shadow: var(--shadow-card);
}

.wechat-title {
  font-size: 32px;
  font-weight: 900;
  margin-bottom: 16px;
  letter-spacing: -0.5px;
  color: #0f172a;
}

.wechat-desc {
  color: var(--text-secondary);
  font-size: 16px;
  margin-bottom: 24px;
  line-height: 1.7;
}

.wechat-list {
  list-style: none;
  margin-bottom: 32px;
}

.wechat-list li {
  font-size: 15px;
  color: var(--text-secondary);
  margin-bottom: 10px;
  padding-left: 4px;
}

.social-links { display: flex; gap: 12px; flex-wrap: wrap; }

.social-btn {
  padding: 10px 20px;
  border-radius: 10px;
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
  transition: var(--transition);
  border: 1px solid var(--border);
  color: var(--text-primary);
  background: #f1f5f9;
}

.social-btn:hover { background: #e2e8f0; }
.wechat-btn:hover { border-color: #07C160; color: #07C160; }
.xiaohongshu-btn:hover { border-color: #FF2442; color: #FF2442; }
.douyin-btn:hover { border-color: #000000; color: #000000; }

/* QR Placeholder */
.qr-placeholder { text-align: center; }

.qr-mock {
  width: 160px; height: 160px;
  background: white;
  border-radius: 16px;
  padding: 16px;
  margin: 0 auto 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  border: 1px solid var(--border);
  box-shadow: 0 4px 12px rgba(0,0,0,0.03);
}

.qr-grid {
  width: 100%; height: 100%;
  background:
    repeating-linear-gradient(
      0deg,
      #0f172a 0px, #0f172a 6px,
      transparent 6px, transparent 12px
    ),
    repeating-linear-gradient(
      90deg,
      #0f172a 0px, #0f172a 6px,
      transparent 6px, transparent 12px
    );
  opacity: 0.1;
  border-radius: 4px;
}

.qr-corner {
  position: absolute;
  width: 28px; height: 28px;
  border: 4px solid #0f172a;
}

.qr-corner.tl { top: 12px; left: 12px; border-right: none; border-bottom: none; }
.qr-corner.tr { top: 12px; right: 12px; border-left: none; border-bottom: none; }
.qr-corner.bl { bottom: 12px; left: 12px; border-right: none; border-top: none; }

.qr-label { font-size: 14px; color: var(--text-secondary); margin-bottom: 4px; }
.qr-sublabel { font-size: 16px; font-weight: 700; color: var(--text-primary); }

/* =========== FOOTER =========== */
.site-footer {
  background: #ffffff;
  border-top: 1px solid var(--border);
  padding: 60px 0 32px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 48px;
}

.footer-logo {
  font-size: 20px;
  font-weight: 800;
  margin-bottom: 12px;
}

.footer-tagline {
  font-size: 16px;
  color: var(--accent-gold);
  margin-bottom: 12px;
}

.footer-desc { font-size: 13px; color: var(--text-muted); line-height: 1.7; }

.footer-links h4 {
  font-size: 14px;
  font-weight: 700;
  margin-bottom: 16px;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.footer-links a {
  display: block;
  font-size: 14px;
  color: var(--text-secondary);
  text-decoration: none;
  margin-bottom: 10px;
  transition: var(--transition);
}

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

.footer-bottom {
  border-top: 1px solid var(--border);
  padding-top: 24px;
  text-align: center;
  color: var(--text-muted);
  font-size: 13px;
}

/* =========== MODAL =========== */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.4);
  backdrop-filter: blur(8px);
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease;
}

.modal-overlay.open {
  opacity: 1;
  pointer-events: all;
}

.modal-container {
  background: #ffffff;
  border: 1px solid var(--border);
  border-radius: 24px;
  width: 100%;
  max-width: 820px; /* 大幅增加宽度，用于展示产品架构与上手路径 */
  max-height: 90vh;
  overflow-y: auto;
  position: relative;
  transform: translateY(20px);
  transition: transform 0.3s ease;
  box-shadow: 0 30px 60px -15px rgba(0,0,0,0.15);
}

.modal-overlay.open .modal-container {
  transform: translateY(0);
}

.modal-close {
  position: absolute;
  top: 20px; right: 20px;
  width: 36px; height: 36px;
  border-radius: 10px;
  background: #f1f5f9;
  border: 1px solid var(--border);
  color: var(--text-secondary);
  font-size: 16px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
  z-index: 10;
}

.modal-close:hover { background: #e2e8f0; color: var(--text-primary); }

/* Modal Content */
.modal-hero {
  padding: 40px;
  border-bottom: 1px solid var(--border);
  position: relative;
}

.modal-emoji-wrap {
  width: 72px; height: 72px;
  border-radius: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 36px;
  margin-bottom: 20px;
}

.modal-name {
  font-size: 28px;
  font-weight: 900;
  margin-bottom: 6px;
  letter-spacing: -0.5px;
}

.modal-name-en {
  font-size: 14px;
  color: var(--text-muted);
  font-style: italic;
  margin-bottom: 16px;
}

.modal-summary {
  font-size: 16px;
  color: var(--text-secondary);
  line-height: 1.7;
}

.modal-metrics {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  background: var(--border);
  border-bottom: 1px solid var(--border);
}

.modal-metric {
  background: #ffffff;
  padding: 20px 16px;
  text-align: center;
}

.modal-metric-value {
  font-size: 20px;
  font-weight: 800;
  display: block;
  margin-bottom: 4px;
}

.modal-metric-label {
  font-size: 12px;
  color: var(--text-muted);
}

/* Modal tab navigation */
.modal-tabs {
  display: flex;
  border-bottom: 1px solid var(--border);
  background: #f8fafc;
  padding: 0 40px;
}

.modal-tab-btn {
  padding: 16px 20px;
  background: none;
  border: none;
  font-size: 14px;
  font-weight: 600;
  color: var(--text-secondary);
  cursor: pointer;
  position: relative;
  transition: var(--transition);
}

.modal-tab-btn:hover {
  color: var(--text-primary);
}

.modal-tab-btn.active {
  color: var(--accent-blue);
}

.modal-tab-btn.active::after {
  content: '';
  position: absolute;
  bottom: 0; left: 0; right: 0;
  height: 3px;
  background: var(--accent-blue);
}

.modal-body { padding: 32px 40px; }

.modal-tab-content {
  display: none;
}

.modal-tab-content.active {
  display: block;
  animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

.modal-section { margin-bottom: 24px; }

.modal-section-title {
  font-size: 15px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 8px;
  border-left: 3px solid var(--accent-blue);
  padding-left: 10px;
}

.modal-section-content {
  color: var(--text-secondary);
  font-size: 15px;
  line-height: 1.8;
}

/* Custom styles for structures */
.arch-flow, .loop-flow {
  background: #f8fafc;
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px;
  font-family: inherit;
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-top: 10px;
  position: relative;
}

.arch-flow strong, .loop-flow strong {
  color: var(--text-primary);
}

.step-card {
  display: flex;
  gap: 16px;
  margin-bottom: 16px;
  background: #f8fafc;
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px;
  align-items: flex-start;
}

.step-number {
  background: var(--accent-blue);
  color: #ffffff;
  font-weight: 800;
  font-size: 13px;
  width: 24px; height: 24px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  margin-top: 2px;
}

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

.modal-china-box {
  background: rgba(5,150,105,0.04);
  border: 1px solid rgba(5,150,105,0.1);
  border-radius: 14px;
  padding: 20px 24px;
}

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

.modal-tag {
  background: #f1f5f9;
  border: 1px solid var(--border);
  color: var(--text-secondary);
  font-size: 13px;
  padding: 4px 12px;
  border-radius: 8px;
}

/* Replicability Bar */
.rep-bar {
  display: flex;
  align-items: center;
  gap: 12px;
  background: #f8fafc;
  padding: 16px;
  border-radius: 12px;
  border: 1px solid var(--border);
}

.rep-track {
  flex: 1;
  height: 8px;
  background: rgba(15, 23, 42, 0.05);
  border-radius: 100px;
  overflow: hidden;
}

.rep-fill {
  height: 100%;
  border-radius: 100px;
  background: var(--gradient-gold);
}

.rep-score { font-size: 16px; font-weight: 800; color: var(--accent-gold); }

/* =========== SUBSCRIBE MODAL =========== */
.subscribe-overlay {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.4);
  backdrop-filter: blur(8px);
  z-index: 1001;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease;
}

.subscribe-overlay.open {
  opacity: 1;
  pointer-events: all;
}

.subscribe-modal {
  background: #ffffff;
  border: 1px solid var(--border);
  border-radius: 24px;
  padding: 48px;
  max-width: 480px;
  width: 100%;
  text-align: center;
  position: relative;
  transform: scale(0.95);
  transition: transform 0.3s ease;
  box-shadow: 0 30px 60px -15px rgba(0,0,0,0.15);
}

.subscribe-overlay.open .subscribe-modal { transform: scale(1); }

.subscribe-icon { font-size: 48px; margin-bottom: 20px; }

.subscribe-modal h3 {
  font-size: 24px;
  font-weight: 800;
  margin-bottom: 12px;
  color: #0f172a;
}

.subscribe-modal p {
  color: var(--text-secondary);
  font-size: 15px;
  line-height: 1.7;
  margin-bottom: 28px;
}

.subscribe-form { display: flex; flex-direction: column; gap: 12px; margin-bottom: 16px; }

.sub-input {
  background: #f8fafc;
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 14px 18px;
  color: var(--text-primary);
  font-size: 15px;
  font-family: inherit;
  outline: none;
  transition: var(--transition);
}

.sub-input:focus {
  border-color: var(--accent-blue);
  background: #ffffff;
  box-shadow: 0 0 0 3px rgba(37,99,235,0.08);
}

.sub-input::placeholder { color: var(--text-muted); }

.btn-sub-submit {
  background: var(--gradient-gold);
  border: none;
  border-radius: 12px;
  padding: 14px;
  color: #ffffff;
  font-weight: 800;
  font-size: 16px;
  cursor: pointer;
  font-family: inherit;
  transition: var(--transition);
  box-shadow: 0 4px 12px rgba(226, 164, 0, 0.2);
}

.btn-sub-submit:hover { opacity: 0.9; transform: translateY(-1px); }

.sub-note { font-size: 13px; color: var(--text-muted); }

/* =========== ANIMATIONS =========== */
@keyframes fadeInDown {
  from { opacity: 0; transform: translateY(-16px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* =========== RESPONSIVE =========== */
@media (max-width: 900px) {
  .main-nav, .header-actions { display: none; }
  .mobile-menu-btn { display: block; }
  .categories-grid { grid-template-columns: repeat(2, 1fr); }
  .radar-content { grid-template-columns: 1fr; }
  .radar-visual { display: none; }
  .wechat-card { grid-template-columns: 1fr; gap: 40px; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .modal-metrics { grid-template-columns: repeat(2, 1fr); }
  .hero-stats { gap: 20px; }
  .modal-tabs { padding: 0 24px; }
}

@media (max-width: 600px) {
  .featured-grid, .projects-grid { grid-template-columns: 1fr; }
  .categories-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr; }
  .hero-title { font-size: 34px; letter-spacing: -1px; }
  .modal-hero, .modal-body { padding: 24px; }
  .wechat-card { padding: 32px 24px; }
  .modal-tabs { padding: 0 12px; }
  .modal-tab-btn { padding: 12px 10px; font-size: 13px; }
}

/* Scrollbar */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg-dark); }
::-webkit-scrollbar-thumb { background: #cbd5e1; border-radius: 100px; }

/* Selection */
::selection { background: rgba(37,99,235,0.1); color: var(--text-primary); }