/**
 * Common Styles
 * Shared styles for header and footer across all pages
 */

:root {
  --primary-color: #333333;
  --secondary-color: #555555;
  --accent-color: #666666;
  --text-color: #222222;
  --text-light: #666666;
  --bg-primary: #ffffff;
  --bg-secondary: #f8f9fa;
  --surface-color: #ffffff;
  --border-color: #dee2e6;
  --shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
  --gradient: linear-gradient(135deg, #333333, #555555);
}

/* ===== HEADER ===== */
header {
  background: var(--surface-color);
  border-bottom: 1px solid var(--border-color);
  padding: 1rem 2rem;
  position: sticky;
  top: 0;
  z-index: 1000;
  backdrop-filter: blur(10px);
}

.header-content {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: center;
  align-items: center;
}

header nav {
  display: flex;
  gap: 2rem;
}

header nav a {
  color: var(--text-color);
  text-decoration: none;
  font-weight: 500;
  transition: all 0.3s ease;
  padding: 0.5rem 1rem;
  border-radius: 6px;
}

header nav a:hover {
  color: var(--primary-color);
  background: var(--bg-secondary);
}

header nav a.active {
  color: var(--primary-color);
  background: var(--bg-secondary);
}

/* ===== FOOTER ===== */
footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding: 2rem;
  margin-top: 4rem;
  text-align: center;
}

footer p {
  color: var(--text-light);
  margin: 0;
  font-size: 0.9rem;
}

/* Blog Post Navigation in Footer */
.blog-post-navigation {
  max-width: 1200px;
  margin: 0 auto;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--border-color);
}

.nav-button-container {
  display: flex;
  justify-content: space-between;
  align-items: stretch;
  gap: 2rem;
}

.nav-btn {
  flex: 0 0 auto;
  max-width: 45%;
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1.25rem 1.5rem;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  text-decoration: none;
  color: var(--text-color);
  transition: all 0.3s ease;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.nav-btn:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.12);
  border-color: var(--primary-color);
  background: var(--bg-primary);
}

.nav-btn i {
  font-size: 1.25rem;
  color: var(--primary-color);
  flex-shrink: 0;
}

.nav-text {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  text-align: left;
}

.nav-next .nav-text {
  text-align: right;
}

.nav-label {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-light);
  font-weight: 600;
}

.nav-title {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-color);
  line-height: 1.3;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.nav-prev {
  margin-right: auto;
}

.nav-next {
  margin-left: auto;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
  header {
    padding: 0.75rem 1rem;
  }
  
  .header-content {
    flex-wrap: wrap;
  }
  
  header nav {
    gap: 0.75rem;
    flex-wrap: wrap;
    justify-content: center;
  }
  
  header nav a {
    padding: 0.5rem 1rem;
    font-size: 0.9rem;
  }
  
  footer {
    padding: 1.5rem 1rem;
    margin-top: 2rem;
  }
  
  .footer-content p {
    font-size: 0.85rem;
  }

  .nav-button-container {
    flex-direction: column;
    gap: 1rem;
  }

  .nav-btn {
    max-width: 100%;
    width: 100%;
  }

  .nav-prev {
    margin-right: 0;
  }

  .nav-next {
    margin-left: 0;
    flex-direction: row-reverse;
  }

  .nav-next .nav-text {
    text-align: left;
  }
}

@media (max-width: 480px) {
  header {
    padding: 0.6rem 0.75rem;
  }
  
  header nav {
    gap: 0.5rem;
  }
  
  header nav a {
    padding: 0.4rem 0.75rem;
    font-size: 0.85rem;
  }
  
  footer {
    padding: 1.25rem 0.75rem;
  }

  .nav-btn {
    padding: 1rem;
    gap: 0.75rem;
  }

  .nav-btn i {
    font-size: 1rem;
  }

  .nav-title {
    font-size: 0.85rem;
  }

  .nav-label {
    font-size: 0.7rem;
  }
}

/* ===== DARK MODE TOGGLE BUTTON ===== */
.header-content {
  position: relative;
}

.theme-toggle {
  background: none;
  border: 1px solid var(--border-color);
  color: var(--text-color);
  cursor: pointer;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.95rem;
  transition: all 0.3s ease;
  position: absolute;
  right: 0;
  top: 50%;
  transform: translateY(-50%);
  flex-shrink: 0;
}

.theme-toggle:hover {
  background: var(--bg-secondary);
  border-color: var(--primary-color);
}

.theme-toggle .icon-moon { display: inline; }
.theme-toggle .icon-sun  { display: none; }

html[data-theme="dark"] .theme-toggle .icon-moon { display: none; }
html[data-theme="dark"] .theme-toggle .icon-sun  { display: inline; }

/* ===== DARK MODE — CSS VARIABLES ===== */
html[data-theme="dark"] {
  --primary-color: #c8c8c8;
  --secondary-color: #999999;
  --accent-color: #888888;
  --success-color: #777777;
  --warning-color: #666666;
  --text-color: #e8e8e8;
  --text-light: #aaaaaa;
  --text-muted: #aaaaaa;
  --text-dim: #666666;
  --bg-color: #121212;
  --bg-primary: #121212;
  --bg-secondary: #1e1e1e;
  --bg-tertiary: #2a2a2a;
  --surface-color: #1e1e1e;
  --border-color: #3a3a3a;
  --shadow: 0 4px 20px rgba(0, 0, 0, 0.6);
  --shadow-light: 0 2px 8px rgba(0, 0, 0, 0.5);
  --glow: 0 0 20px rgba(200, 200, 200, 0.05);
  --gradient: linear-gradient(135deg, #c8c8c8, #999999);
  --gradient-primary: linear-gradient(135deg, #1e1e1e, #2a2a2a);
  --gradient-accent: linear-gradient(135deg, #c8c8c8, #999999);
}

/* Smooth transition when switching themes */
html[data-theme="dark"] body,
html[data-theme="dark"] header,
html[data-theme="dark"] footer,
html:not([data-theme="dark"]) body,
html:not([data-theme="dark"]) header,
html:not([data-theme="dark"]) footer {
  transition: background-color 0.25s ease, color 0.25s ease,
              border-color 0.25s ease;
}

/* ===== DARK MODE — HARDCODED COLOR OVERRIDES ===== */

/* Code blocks in post pages */
html[data-theme="dark"] .post-content pre {
  background: #1e2430 !important;
  border-color: #3a3a3a !important;
}

html[data-theme="dark"] .post-content pre code {
  color: #cdd9e5 !important;
  background: none !important;
}

html[data-theme="dark"] .post-content code {
  background: #2a2a2a !important;
  color: #f0883e !important;
}

/* visual-box (monospace ASCII diagrams) */
html[data-theme="dark"] .visual-box {
  background: #1e1e1e !important;
  border-color: #3a3a3a !important;
  color: #cdd9e5 !important;
}

/* Zebra-stripe table rows */
html[data-theme="dark"] .post-content table tbody tr:nth-child(even) {
  background: #222222 !important;
}

/* highlight-box variants */
html[data-theme="dark"] .highlight-box {
  background: #2a2a1a !important;
  border-color: #4a4a28 !important;
  color: #e8e8e8 !important;
}

html[data-theme="dark"] .highlight-box.danger {
  background: #2a1a1a !important;
  border-color: #4a2828 !important;
}

html[data-theme="dark"] .highlight-box.success {
  background: #1a2a1a !important;
  border-color: #284a28 !important;
}

html[data-theme="dark"] .highlight-box.info {
  background: #1a1e2a !important;
  border-color: #28304a !important;
}

html[data-theme="dark"] .highlight-box.warning {
  background: #2a2a1a !important;
  border-color: #4a4a28 !important;
}

/* index.html hero section in dark mode */
html[data-theme="dark"] .hero {
  background: linear-gradient(135deg, #121212 0%, #1a1a1a 100%) !important;
}

/* blog.html hero section */
html[data-theme="dark"] section.hero {
  background: linear-gradient(135deg, #121212 0%, #1a1a1a 100%) !important;
}

/* Inline highlighted table row (flash-attention post) */
html[data-theme="dark"] tr[style*="background: #fff3cd"],
html[data-theme="dark"] tr[style*="background:#fff3cd"] {
  background: #2a2a1a !important;
}