/* ===== Singapore Study Guide - Vaster Blue Theme + SEDA Content Style ===== */

:root {
  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-card: #ffffff;
  --bg-card-hover: #f1f5f9;
  --bg-light: #f5f7fa;
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  --accent: #2563eb;
  --accent-light: #3b82f6;
  --accent-dark: #1d4ed8;
  --accent-glow: rgba(37, 99, 235, 0.15);
  --border: #e2e8f0;
  --border-color: #e2e8f0;
  --border-light: #cbd5e1;
  --success: #10b981;
  --warning: #f59e0b;
  --danger: #ef4444;
  --gradient-primary: linear-gradient(135deg, #eff6ff 0%, #ffffff 100%);
  --gradient-accent: linear-gradient(135deg, #2563eb 0%, #1d4ed8 100%);
  --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.06), 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow-hover: 0 10px 25px -5px rgba(37, 99, 235, 0.1), 0 8px 10px -6px rgba(37, 99, 235, 0.08);
}

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

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.65;
  font-size: 15px;
}

a { color: inherit; text-decoration: none; }
ul { list-style: none; }
img { max-width: 100%; display: block; }

.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== Typography ===== */
h1, h2, h3, h4, h5, h6 { font-weight: 700; line-height: 1.35; }
h1 { font-size: 2.5rem; }
h2 { font-size: 1.85rem; }
h3 { font-size: 1.35rem; }
h4 { font-size: 1.1rem; }

.text-accent { color: var(--accent-light); }
.text-secondary { color: var(--text-secondary); }

/* ===== Navigation ===== */
.navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.04);
}

.navbar-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
  height: 68px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  font-size: 1.25rem;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.logo span {
  color: var(--accent-light);
}

.nav-links {
  display: flex;
  gap: 2px;
  align-items: center;
}

.nav-item {
  position: relative;
}

.nav-item > a {
  display: block;
  padding: 10px 18px;
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-secondary);
  border-radius: 6px;
  transition: all 0.2s;
}

.nav-item > a:hover,
.nav-item > a.active {
  color: var(--text-primary);
  background: rgba(37, 99, 235, 0.1);
}

/* Dropdown */
.dropdown {
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%);
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 8px;
  min-width: 200px;
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.08), 0 4px 10px rgba(0, 0, 0, 0.04);
  opacity: 0;
  visibility: hidden;
  transition: all 0.2s;
  margin-top: 8px;
}

.nav-item:hover .dropdown {
  opacity: 1;
  visibility: visible;
  margin-top: 4px;
}

.dropdown a {
  display: block;
  padding: 10px 14px;
  font-size: 0.9rem;
  color: var(--text-secondary);
  border-radius: 6px;
  transition: all 0.15s;
}

.dropdown a:hover {
  background: rgba(37, 99, 235, 0.15);
  color: var(--text-primary);
}

.nav-cta {
  padding: 8px 20px;
  background: var(--gradient-accent);
  color: white !important;
  border-radius: 6px;
  font-size: 0.9rem;
  font-weight: 600;
  transition: all 0.2s;
}

.nav-cta:hover {
  box-shadow: 0 4px 15px var(--accent-glow);
  transform: translateY(-1px);
}

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

/* ===== Hero Section ===== */
.hero {
  padding: 120px 0 80px;
  background: var(--gradient-primary);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0; right: 0;
  width: 600px; height: 600px;
  background: radial-gradient(circle, rgba(37, 99, 235, 0.15) 0%, transparent 70%);
  pointer-events: none;
}

.hero-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 60px;
  align-items: center;
  position: relative;
}

.hero-label {
  display: inline-block;
  padding: 6px 14px;
  background: rgba(37, 99, 235, 0.15);
  color: var(--accent-light);
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  margin-bottom: 20px;
}

.hero-title {
  font-size: 3rem;
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 20px;
}

.hero-title .highlight {
  background: linear-gradient(135deg, #60a5fa, #2563eb);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: 1.1rem;
  color: var(--text-secondary);
  margin-bottom: 32px;
  line-height: 1.7;
}

.hero-stats {
  display: flex;
  gap: 40px;
  margin-bottom: 32px;
}

.hero-stat-num {
  font-size: 2rem;
  font-weight: 800;
  color: var(--accent-light);
}

.hero-stat-label {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-top: 4px;
}

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

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: all 0.2s;
}

.btn-primary {
  background: var(--gradient-accent);
  color: white;
}

.btn-primary:hover {
  box-shadow: 0 6px 20px var(--accent-glow);
  transform: translateY(-2px);
}

.btn-outline {
  background: transparent;
  color: var(--text-primary);
  border: 1px solid var(--border-light);
}

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

.hero-visual {
  position: relative;
}

.hero-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 32px;
  box-shadow: var(--shadow-card);
}

/* ===== Stats Bar ===== */
.stats-bar {
  padding: 48px 0;
  background: var(--bg-secondary);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.stat-item {
  text-align: center;
  padding: 24px 16px;
}

.stat-item-num {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--accent-light);
  margin-bottom: 8px;
}

.stat-item-label {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

/* ===== Section Common ===== */
.section {
  padding: 80px 0;
}

.section-alt {
  background: var(--bg-secondary);
}

.section-header {
  text-align: center;
  margin-bottom: 56px;
}

.section-label {
  display: inline-block;
  font-size: 0.8rem;
  color: var(--accent-light);
  text-transform: uppercase;
  letter-spacing: 0.15em;
  font-weight: 600;
  margin-bottom: 12px;
}

.section-title {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 16px;
}

.section-desc {
  color: var(--text-secondary);
  font-size: 1rem;
  max-width: 640px;
  margin: 0 auto;
}

/* ===== Card Grid ===== */
.card-grid {
  display: grid;
  gap: 20px;
}

.card-grid-2 { grid-template-columns: repeat(2, 1fr); }
.card-grid-3 { grid-template-columns: repeat(3, 1fr); }
.card-grid-4 { grid-template-columns: repeat(4, 1fr); }

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 28px;
  transition: all 0.3s;
}

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

.card-icon {
  width: 48px;
  height: 48px;
  background: rgba(37, 99, 235, 0.15);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 16px;
}

.card-title {
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 10px;
}

.card-desc {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.6;
  margin-bottom: 16px;
}

.card-link {
  color: var(--accent-light);
  font-size: 0.9rem;
  font-weight: 500;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.card-link:hover {
  gap: 10px;
}

/* ===== Tags ===== */
.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 12px;
}

.tag {
  display: inline-block;
  padding: 3px 10px;
  border-radius: 4px;
  font-size: 0.75rem;
  font-weight: 500;
}

.tag-blue { background: rgba(37, 99, 235, 0.15); color: #60a5fa; }
.tag-green { background: rgba(16, 185, 129, 0.15); color: #34d399; }
.tag-orange { background: rgba(245, 158, 11, 0.15); color: #fbbf24; }
.tag-purple { background: rgba(168, 85, 247, 0.15); color: #c084fc; }
.tag-red { background: rgba(239, 68, 68, 0.15); color: #f87171; }

/* ===== Tier Badges ===== */
.tier {
  display: inline-block;
  padding: 4px 10px;
  border-radius: 4px;
  font-size: 0.75rem;
  font-weight: 600;
}

.tier-1 { background: rgba(239, 68, 68, 0.15); color: #f87171; }
.tier-2 { background: rgba(245, 158, 11, 0.15); color: #fbbf24; }
.tier-3 { background: rgba(59, 130, 246, 0.15); color: #60a5fa; }
.tier-4 { background: rgba(100, 116, 139, 0.15); color: #94a3b8; }

/* ===== Page Header (Content Pages) ===== */
.page-header {
  padding: 120px 0 60px;
  background: var(--gradient-primary);
  position: relative;
  overflow: hidden;
}

.page-header::before {
  content: '';
  position: absolute;
  bottom: 0; left: 0; right: 0;
  height: 1px;
  background: var(--border);
}

.breadcrumb {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 24px;
}

.breadcrumb a {
  color: var(--text-secondary);
  transition: color 0.2s;
}

.breadcrumb a:hover { color: var(--accent-light); }

.breadcrumb .sep { margin: 0 8px; color: var(--text-muted); }

.page-header h1 {
  font-size: 2.25rem;
  font-weight: 800;
  margin-bottom: 16px;
}

.page-header .subtitle {
  font-size: 1rem;
  color: var(--text-secondary);
  max-width: 720px;
  line-height: 1.7;
}

.page-stats {
  display: flex;
  gap: 48px;
  margin-top: 32px;
  flex-wrap: wrap;
}

.page-stat-num {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--accent-light);
}

.page-stat-label {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-top: 4px;
}

/* ===== Filter Bar ===== */
.filter-bar {
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
  padding: 24px 0;
  position: sticky;
  top: 68px;
  z-index: 100;
  backdrop-filter: blur(10px);
}

.filter-group {
  margin-bottom: 16px;
}

.filter-group:last-child { margin-bottom: 0; }

.filter-label {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 8px;
  font-weight: 500;
}

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

.filter-tag {
  padding: 6px 14px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 20px;
  font-size: 0.85rem;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.2s;
}

.filter-tag:hover {
  border-color: var(--accent);
  color: var(--text-primary);
}

.filter-tag.active {
  background: var(--accent);
  border-color: var(--accent);
  color: white;
}

/* ===== School Card Grid (SEDA style) ===== */
.school-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.school-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 20px;
  transition: all 0.25s;
  cursor: pointer;
}

.school-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(37, 99, 235, 0.1);
}

.school-card-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 12px;
}

.school-abbr {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--accent-light);
  letter-spacing: 0.05em;
}

.school-name {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 4px;
}

.school-name-cn {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 8px;
}

.school-desc {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.5;
  margin-bottom: 12px;
}

.school-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8rem;
}

.school-location {
  color: var(--text-muted);
}

.school-detail-link {
  color: var(--accent-light);
  font-weight: 500;
}

/* ===== Content Section ===== */
.content-section {
  padding: 60px 0;
}

.content-section h2 {
  font-size: 1.5rem;
  margin-bottom: 20px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border);
}

.content-section h3 {
  font-size: 1.2rem;
  margin: 28px 0 14px;
  color: var(--accent-light);
}

.content-section p {
  color: var(--text-secondary);
  margin-bottom: 14px;
  line-height: 1.75;
}

.content-section ul,
.content-section ol {
  color: var(--text-secondary);
  margin: 14px 0 20px 24px;
}

.content-section li {
  margin-bottom: 8px;
  line-height: 1.7;
}

/* ===== Table ===== */
.table-wrap {
  overflow-x: auto;
  margin: 20px 0;
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
}

.data-table th,
.data-table td {
  padding: 12px 16px;
  text-align: left;
  border-bottom: 1px solid var(--border);
}

.data-table th {
  background: var(--bg-secondary);
  font-weight: 600;
  color: var(--text-primary);
  font-size: 0.85rem;
}

.data-table tr:hover td {
  background: rgba(37, 99, 246, 0.05);
}

.data-table td {
  color: var(--text-secondary);
}

/* ===== Alert / Notice ===== */
.alert {
  padding: 16px 20px;
  border-radius: 8px;
  margin: 20px 0;
  font-size: 0.9rem;
  line-height: 1.6;
}

.alert-info {
  background: rgba(37, 99, 235, 0.1);
  border-left: 3px solid var(--accent);
  color: var(--text-secondary);
}

.alert-success {
  background: rgba(16, 185, 129, 0.1);
  border-left: 3px solid var(--success);
  color: var(--text-secondary);
}

.alert-warning {
  background: rgba(245, 158, 11, 0.1);
  border-left: 3px solid var(--warning);
  color: var(--text-secondary);
}

/* ===== CTA Section ===== */
.cta-section {
  padding: 80px 0;
  text-align: center;
  background: var(--gradient-primary);
  position: relative;
}

.cta-title {
  font-size: 1.85rem;
  font-weight: 700;
  margin-bottom: 16px;
}

.cta-desc {
  color: var(--text-secondary);
  margin-bottom: 32px;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

/* ===== Footer ===== */
.footer {
  background: #f8fafc;
  border-top: 1px solid var(--border);
  padding: 60px 0 24px;
}

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

.footer-brand {
  font-size: 1.25rem;
  font-weight: 800;
  margin-bottom: 16px;
}

.footer-brand span { color: var(--accent-light); }

.footer-desc {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.7;
}

.footer-title {
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 16px;
  color: var(--text-primary);
}

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

.footer-links a {
  color: var(--text-secondary);
  font-size: 0.85rem;
  transition: color 0.2s;
}

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

.footer-bottom {
  padding-top: 24px;
  border-top: 1px solid var(--border);
  text-align: center;
  color: var(--text-muted);
  font-size: 0.8rem;
}

/* ===== Sidebar Layout ===== */
.sidebar-layout {
  display: grid;
  grid-template-columns: 260px 1fr;
  gap: 40px;
  align-items: start;
}

.sidebar {
  position: sticky;
  top: 100px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px;
}

.sidebar-title {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border);
}

.sidebar-nav li {
  margin-bottom: 4px;
}

.sidebar-nav a {
  display: block;
  padding: 10px 14px;
  border-radius: 6px;
  font-size: 0.9rem;
  color: var(--text-secondary);
  transition: all 0.15s;
}

.sidebar-nav a:hover,
.sidebar-nav a.active {
  background: rgba(37, 99, 235, 0.15);
  color: var(--text-primary);
}

/* ===== News / Article Cards ===== */
.news-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.news-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
  transition: all 0.3s;
}

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

.news-card-img {
  height: 160px;
  background: linear-gradient(135deg, var(--bg-secondary), var(--bg-card));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3rem;
}

.news-card-body {
  padding: 20px;
}

.news-card-category {
  font-size: 0.75rem;
  color: var(--accent-light);
  font-weight: 600;
  margin-bottom: 8px;
}

.news-card-title {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 8px;
  line-height: 1.4;
}

.news-card-excerpt {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 12px;
}

.news-card-date {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* ===== Feature Section (Two Column) ===== */
.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.two-col-visual {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 40px;
  min-height: 300px;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* ===== Responsive ===== */
@media (max-width: 1024px) {
  .card-grid-4 { grid-template-columns: repeat(2, 1fr); }
  .school-grid { grid-template-columns: repeat(2, 1fr); }
  .news-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .hero-inner { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .sidebar-layout { grid-template-columns: 1fr; }
  .sidebar { position: static; }
  .two-col { grid-template-columns: 1fr; gap: 32px; }
}

@media (max-width: 768px) {
  .nav-links { display: none; }
  .mobile-menu-btn { display: block; }
  .nav-links.active {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 68px;
    left: 0; right: 0;
    background: var(--bg-secondary);
    padding: 16px;
    border-bottom: 1px solid var(--border);
  }
  .hero-title { font-size: 2rem; }
  .page-header h1 { font-size: 1.75rem; }
  .card-grid-2,
  .card-grid-3,
  .card-grid-4 { grid-template-columns: 1fr; }
  .school-grid { grid-template-columns: 1fr; }
  .news-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; gap: 32px; }
  .hero-stats { gap: 24px; flex-wrap: wrap; }
  .page-stats { gap: 24px; }
  .section { padding: 56px 0; }
}