@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+TC:wght@400;500;600;700&family=Inter:wght@400;500;600;700&display=swap');

*, *::before, *::after {
  box-sizing: border-box;
}

:root {
  --color-bg: #fafafa;
  --color-surface: #ffffff;
  --color-text: #1a1a2e;
  --color-text-secondary: #6b7280;
  --color-accent: #6366f1;
  --color-accent-light: #818cf8;
  --color-accent-bg: #eef2ff;
  --color-border: #e5e7eb;
  --color-border-hover: #c7d2fe;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.08);
  --shadow-lg: 0 8px 30px rgba(0,0,0,0.1);
  --radius: 16px;
  --radius-sm: 10px;
  --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', 'Noto Sans TC', -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  margin: 0;
  padding: 0;
  line-height: 1.75;
  background: var(--color-bg);
  color: var(--color-text);
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color var(--transition);
}

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

img {
  max-width: 100%;
}

/* ── Header ── */

.site-header {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(12px);
  background: rgba(255,255,255,0.85);
}

.header-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0.9rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: var(--color-text);
}

.brand:hover {
  color: var(--color-text);
}

.logo-circle {
  width: 42px;
  height: 42px;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--color-accent), #a78bfa);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1rem;
  color: #fff;
  flex-shrink: 0;
}

.site-title {
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.site-subtitle {
  font-size: 0.78rem;
  color: var(--color-text-secondary);
  margin-top: 1px;
}

.main-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem;
  font-size: 0.88rem;
}

.main-nav a {
  color: var(--color-text-secondary);
  text-decoration: none;
  padding: 0.4rem 0.85rem;
  border-radius: 999px;
  font-weight: 500;
  transition: all var(--transition);
}

.main-nav a:hover,
.main-nav a.active {
  background: var(--color-accent-bg);
  color: var(--color-accent);
}

/* ── Main ── */

main {
  max-width: 1100px;
  margin: 0 auto 3rem;
  padding: 2rem 1.5rem;
}

/* ── Hero ── */

.hero {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: 2rem;
  align-items: center;
  margin-bottom: 3rem;
  padding: 2.5rem 2rem;
  background: linear-gradient(135deg, var(--color-accent-bg), #fdf4ff, #eff6ff);
  border-radius: var(--radius);
  border: 1px solid var(--color-border);
}

.hero-content h1 {
  font-size: 2rem;
  font-weight: 700;
  line-height: 1.35;
  margin: 0 0 0.6rem;
  letter-spacing: -0.02em;
  color: var(--color-text);
}

.hero-content p {
  color: var(--color-text-secondary);
  margin: 0;
  font-size: 1rem;
  line-height: 1.7;
}

.hero-actions {
  margin-top: 1.5rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.btn-primary,
.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.65rem 1.4rem;
  border-radius: 999px;
  font-size: 0.9rem;
  font-weight: 600;
  text-decoration: none;
  transition: all var(--transition);
  cursor: pointer;
}

.btn-primary {
  background: var(--color-accent);
  color: #fff;
  box-shadow: 0 2px 8px rgba(99,102,241,0.3);
}

.btn-primary:hover {
  background: var(--color-accent-light);
  color: #fff;
  transform: translateY(-1px);
  box-shadow: 0 4px 14px rgba(99,102,241,0.35);
}

.btn-secondary {
  background: var(--color-surface);
  color: var(--color-text);
  border: 1px solid var(--color-border);
}

.btn-secondary:hover {
  border-color: var(--color-border-hover);
  background: var(--color-accent-bg);
  color: var(--color-accent);
}

.hero-card {
  background: var(--color-surface);
  border-radius: var(--radius);
  padding: 1.5rem;
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-md);
  transition: all var(--transition);
}

.hero-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

.hero-card h2 {
  font-size: 0.75rem;
  margin: 0 0 0.8rem;
  color: var(--color-accent);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  font-weight: 600;
}

.hero-card h3 {
  font-size: 1.1rem;
  margin: 0 0 0.5rem;
  font-weight: 600;
  line-height: 1.45;
}

.hero-card h3 a {
  color: var(--color-text);
}

.hero-card h3 a:hover {
  color: var(--color-accent);
}

.hero-card .meta {
  font-size: 0.8rem;
  color: var(--color-text-secondary);
  margin: 0 0 0.5rem;
}

.hero-card .summary {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  line-height: 1.65;
  margin: 0;
}

/* ── Sections ── */

.section {
  margin-top: 3rem;
}

.section-header {
  margin-bottom: 1.5rem;
}

.section-header h2 {
  font-size: 1.4rem;
  font-weight: 700;
  margin: 0 0 0.3rem;
  letter-spacing: -0.01em;
  position: relative;
  display: inline-block;
}

.section-header h2::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 40px;
  height: 3px;
  background: var(--color-accent);
  border-radius: 2px;
}

.section-header p {
  margin: 0.6rem 0 0;
  color: var(--color-text-secondary);
  font-size: 0.9rem;
}

/* ── Post Grid ── */

.post-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
}

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

/* ── Featured Post Card ── */

.post-card-featured {
  background: var(--color-surface);
  border-radius: var(--radius);
  padding: 2rem;
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-md);
  margin-bottom: 1.5rem;
  position: relative;
  overflow: hidden;
  transition: all var(--transition);
}

.post-card-featured::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--color-accent), #a78bfa, #f472b6);
}

.post-card-featured:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

.post-card-featured-body .post-category {
  margin-bottom: 0.8rem;
}

.post-card-featured-body h3 {
  font-size: 1.35rem;
  font-weight: 700;
  margin: 0 0 0.5rem;
  line-height: 1.4;
}

.post-card-featured-body h3 a {
  color: var(--color-text);
}

.post-card-featured-body h3 a:hover {
  color: var(--color-accent);
}

.post-card-featured-body .post-meta {
  font-size: 0.82rem;
  color: var(--color-text-secondary);
  margin: 0 0 0.6rem;
}

.post-card-featured-body .post-excerpt {
  font-size: 0.95rem;
  color: var(--color-text-secondary);
  line-height: 1.7;
  margin: 0 0 1rem;
}

.read-more {
  display: inline-flex;
  align-items: center;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--color-accent);
  text-decoration: none;
  transition: all var(--transition);
}

.read-more:hover {
  color: var(--color-accent-light);
  gap: 0.3rem;
}

/* ── Post Card ── */

.post-card {
  background: var(--color-surface);
  border-radius: var(--radius);
  padding: 1.5rem;
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}

.post-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-accent), #a78bfa);
  opacity: 0;
  transition: opacity var(--transition);
}

.post-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-3px);
  border-color: var(--color-border-hover);
}

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

.post-category {
  display: inline-block;
  font-size: 0.72rem;
  color: var(--color-accent);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-weight: 600;
  margin: 0 0 0.6rem;
  background: var(--color-accent-bg);
  padding: 0.2rem 0.6rem;
  border-radius: 999px;
}

.post-card h3 {
  margin: 0 0 0.4rem;
  font-size: 1.05rem;
  font-weight: 600;
  line-height: 1.45;
}

.post-card h3 a {
  color: var(--color-text);
}

.post-card h3 a:hover {
  color: var(--color-accent);
}

.post-card .post-meta {
  font-size: 0.8rem;
  color: var(--color-text-secondary);
  margin: 0;
}

.post-card .post-excerpt {
  margin: 0.6rem 0 0;
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  line-height: 1.65;
}

/* ── Post List (compact) ── */

.post-list {
  margin-top: 1.5rem;
  border-top: 1px solid var(--color-border);
}

.post-list-item {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1rem 0.5rem;
  border-bottom: 1px solid var(--color-border);
  transition: background var(--transition);
}

.post-list-item:hover {
  background: var(--color-accent-bg);
  border-radius: var(--radius-sm);
}

.post-list-item .post-category {
  margin: 0;
  flex-shrink: 0;
  font-size: 0.68rem;
  padding: 0.15rem 0.55rem;
}

.post-list-item h3 {
  flex: 1;
  margin: 0;
  font-size: 0.95rem;
  font-weight: 500;
  line-height: 1.4;
}

.post-list-item h3 a {
  color: var(--color-text);
  text-decoration: none;
}

.post-list-item h3 a:hover {
  color: var(--color-accent);
}

.post-list-item .post-meta {
  flex-shrink: 0;
  font-size: 0.78rem;
  color: var(--color-text-secondary);
  white-space: nowrap;
}

/* ── Category Grid ── */

.section-categories {
  margin-bottom: 2rem;
}

.category-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
  margin-top: 0;
}

.category-card {
  background: var(--color-surface);
  border-radius: var(--radius-sm);
  padding: 1.2rem 1rem;
  border: 1px solid var(--color-border);
  transition: all var(--transition);
  text-align: center;
}

.category-card:hover {
  border-color: var(--color-border-hover);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.category-card h3 {
  margin: 0 0 0.4rem;
  font-size: 0.95rem;
  font-weight: 600;
}

.category-icon {
  font-size: 1.6rem;
  margin-bottom: 0.5rem;
}

.category-card p {
  margin: 0;
  font-size: 0.82rem;
  color: var(--color-text-secondary);
  line-height: 1.55;
}

/* ── Footer ── */

.site-footer {
  border-top: 1px solid var(--color-border);
  background: var(--color-surface);
}

.footer-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 1.5rem 1.5rem 1.8rem;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  font-size: 0.85rem;
  color: var(--color-text-secondary);
}

.footer-title {
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 0.15rem;
}

.footer-text {
  margin: 0;
}

.footer-meta {
  text-align: right;
}

.footer-note {
  margin-top: 0.2rem;
  font-size: 0.78rem;
  color: #9ca3af;
}

/* ── Article Page ── */

.post {
  max-width: 760px;
  margin: 2rem auto 3rem;
  background: var(--color-surface);
  border-radius: var(--radius);
  padding: 2.5rem 2.5rem 2rem;
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-md);
}

.post h1 {
  margin: 0 0 0.5rem;
  font-size: 1.75rem;
  font-weight: 700;
  line-height: 1.35;
  letter-spacing: -0.02em;
}

.post .meta {
  font-size: 0.82rem;
  color: var(--color-text-secondary);
  padding-bottom: 1.2rem;
  border-bottom: 1px solid var(--color-border);
  margin-bottom: 1.5rem;
}

.post h2 {
  margin: 2rem 0 0.8rem;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-text);
  padding-bottom: 0.4rem;
  border-bottom: 2px solid var(--color-accent-bg);
}

.post h3 {
  margin: 1.5rem 0 0.6rem;
  font-size: 1.05rem;
  font-weight: 600;
}

.post p {
  font-size: 0.95rem;
  line-height: 1.85;
  color: #374151;
}

.post ul,
.post ol {
  padding-left: 1.4rem;
  color: #374151;
}

.post li {
  margin-bottom: 0.35rem;
  line-height: 1.75;
}

.post blockquote {
  margin: 1.2rem 0;
  padding: 1rem 1.2rem;
  border-left: 4px solid var(--color-accent);
  background: var(--color-accent-bg);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  font-style: italic;
}

.post blockquote p {
  margin: 0;
  color: #4338ca;
}

.post table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.2rem 0;
  font-size: 0.9rem;
  border-radius: var(--radius-sm);
  overflow: hidden;
  border: 1px solid var(--color-border);
}

.post table th,
.post table td {
  padding: 0.6rem 0.8rem;
  text-align: left;
}

.post table th {
  background: var(--color-accent-bg);
  font-weight: 600;
  color: var(--color-accent);
  border-bottom: 2px solid var(--color-border);
}

.post table td {
  border-bottom: 1px solid var(--color-border);
}

.post table tbody tr:hover {
  background: #f9fafb;
}

.post strong {
  color: var(--color-text);
  font-weight: 600;
}

/* ── Tagline (for article page simple header) ── */

.tagline {
  color: var(--color-text-secondary);
  font-size: 0.85rem;
  margin: 0;
}

/* ── Responsive ── */

@media (max-width: 900px) {
  .header-inner {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.6rem;
  }

  .main-nav {
    justify-content: flex-start;
  }

  .hero {
    grid-template-columns: 1fr;
    padding: 1.8rem 1.5rem;
  }

  .hero-content h1 {
    font-size: 1.6rem;
  }

  .post-grid {
    grid-template-columns: 1fr;
  }

  .post-grid-3 {
    grid-template-columns: 1fr;
  }

  .post-card-featured-body h3 {
    font-size: 1.15rem;
  }

  .post-list-item {
    flex-wrap: wrap;
    gap: 0.4rem;
  }

  .post-list-item .post-meta {
    width: 100%;
    order: 3;
  }

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

  .footer-inner {
    flex-direction: column;
    text-align: left;
  }

  .footer-meta {
    text-align: left;
  }

  .post {
    padding: 1.5rem 1.2rem;
    margin: 1rem auto 2rem;
  }

  .post h1 {
    font-size: 1.4rem;
  }
}

@media (max-width: 560px) {
  main {
    padding: 1.2rem 1rem;
  }

  .hero {
    padding: 1.5rem 1.2rem;
  }

  .hero-content h1 {
    font-size: 1.35rem;
  }

  .category-grid {
    grid-template-columns: 1fr;
  }

  .hero-actions {
    flex-direction: column;
  }

  .btn-primary,
  .btn-secondary {
    width: 100%;
    text-align: center;
  }
}