/* ==========================================================
   Trident Engine — GitHub Pages Theme
   Color palette derived from a VS-Dark-style IDE theme
   ========================================================== */

/* --- Reset & Base ----------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg-primary:   #1a1a1e;
  --bg-secondary: #222226;
  --bg-card:      #26262b;
  --bg-card-hover:#2c2c32;
  --bg-code:      #1e1e1e;
  --border:       #333338;
  --border-hover: #48484f;

  --text-primary:   #d4d4d4;
  --text-secondary: #9e9e9e;
  --text-muted:     #6a6a6f;

  --accent-blue:   #569cd6;
  --accent-teal:   #4ec9b0;
  --accent-yellow: #dcdcaa;
  --accent-orange: #ce9178;
  --accent-green:  #6a9955;
  --accent-purple: #c586c0;
  --accent-red:    #f44747;

  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'Cascadia Code', 'Fira Code', 'JetBrains Mono', Consolas, monospace;

  --max-width: 1200px;
  --header-h: 60px;
  --radius: 6px;
  --transition: 0.2s ease;
}

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

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

img { max-width: 100%; height: auto; display: block; }

/* --- Header / Nav ---------------------------------------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  height: var(--header-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.site-logo {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.02em;
  display: flex;
  align-items: center;
  gap: 8px;
}

.site-logo .logo-icon { width: 28px; height: 28px; image-rendering: pixelated; }

.nav-links { display: flex; gap: 8px; list-style: none; }

.nav-links a {
  padding: 6px 14px;
  border-radius: var(--radius);
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 500;
  transition: background var(--transition), color var(--transition);
}

.nav-links a:hover,
.nav-links a.active {
  background: rgba(86,156,214,0.1);
  color: var(--accent-blue);
}

/* Mobile hamburger */
.nav-toggle { display: none; background: none; border: none; cursor: pointer; padding: 8px; }
.nav-toggle span {
  display: block; width: 22px; height: 2px;
  background: var(--text-primary); margin: 5px 0;
  transition: var(--transition);
}

@media (max-width: 768px) {
  .nav-toggle { display: block; }
  .nav-links {
    display: none;
    position: absolute;
    top: var(--header-h);
    left: 0; right: 0;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    flex-direction: column;
    padding: 12px 24px;
    gap: 4px;
  }
  .nav-links.open { display: flex; }
}

/* --- Hero ------------------------------------------------------ */
.hero {
  padding: 80px 24px;
  text-align: center;
  background:
    radial-gradient(ellipse at 50% 0%, rgba(78,201,176,0.08) 0%, transparent 60%),
    var(--bg-primary);
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 3.2rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  margin-bottom: 16px;
}

.accent { color: var(--accent-teal); }

.hero p {
  font-size: 1.15rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto 32px;
}

.hero-actions { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }

.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 24px;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 0.95rem;
  border: none;
  cursor: pointer;
  transition: background var(--transition), transform 0.15s ease;
}
.btn:active { transform: scale(0.97); }

.btn-primary {
  background: var(--accent-blue);
  color: #fff;
}
.btn-primary:hover { background: #6db0e6; color: #fff; }

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

/* --- Container ------------------------------------------------- */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* --- Section titles -------------------------------------------- */
.section-title {
  font-size: 1.6rem;
  font-weight: 700;
  margin-bottom: 8px;
  letter-spacing: -0.02em;
}

.section-subtitle {
  color: var(--text-secondary);
  margin-bottom: 32px;
}

/* --- Blog layout ----------------------------------------------- */
.blog-layout {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: 40px;
  padding: 48px 0;
}

@media (max-width: 960px) {
  .blog-layout { grid-template-columns: 1fr; }
}

/* --- Post cards ------------------------------------------------ */
.post-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 24px;
}

.post-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: border-color var(--transition), transform var(--transition), box-shadow var(--transition);
}

.post-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0,0,0,0.3);
}

.post-card-thumb {
  width: 100%;
  aspect-ratio: 16/9;
  object-fit: cover;
  background: var(--bg-secondary);
}

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

.post-card-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 8px;
}

.post-card-title {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 8px;
  line-height: 1.35;
}

.post-card-title a { color: var(--text-primary); }
.post-card-title a:hover { color: var(--accent-blue); }

.post-card-excerpt {
  font-size: 0.9rem;
  color: var(--text-secondary);
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
  margin-bottom: 14px;
}

.post-card-tags { display: flex; flex-wrap: wrap; gap: 6px; }

/* --- Tags / Badges --------------------------------------------- */
.tag {
  display: inline-block;
  padding: 2px 10px;
  border-radius: 999px;
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  border: 1px solid var(--border);
  color: var(--text-secondary);
  transition: border-color var(--transition), color var(--transition);
  cursor: pointer;
}

.tag:hover { border-color: var(--accent-blue); color: var(--accent-blue); }

.tag[data-color="blue"]   { border-color: var(--accent-blue);   color: var(--accent-blue); }
.tag[data-color="teal"]   { border-color: var(--accent-teal);   color: var(--accent-teal); }
.tag[data-color="yellow"] { border-color: var(--accent-yellow); color: var(--accent-yellow); }
.tag[data-color="orange"] { border-color: var(--accent-orange); color: var(--accent-orange); }
.tag[data-color="green"]  { border-color: var(--accent-green);  color: var(--accent-green); }
.tag[data-color="purple"] { border-color: var(--accent-purple); color: var(--accent-purple); }

.tag.active {
  background: rgba(86,156,214,0.15);
  border-color: var(--accent-blue);
  color: var(--accent-blue);
}

/* --- Sidebar --------------------------------------------------- */
.sidebar { display: flex; flex-direction: column; gap: 28px; }

.sidebar-section h3 {
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border);
}

.sidebar-tags { display: flex; flex-wrap: wrap; gap: 6px; }

.sidebar-categories { list-style: none; }

.sidebar-categories li a {
  display: flex;
  justify-content: space-between;
  padding: 6px 0;
  color: var(--text-secondary);
  font-size: 0.9rem;
  border-bottom: 1px solid rgba(51,51,56,0.5);
}

.sidebar-categories li a:hover { color: var(--accent-blue); }

.sidebar-categories .count {
  background: var(--bg-primary);
  padding: 1px 8px;
  border-radius: 999px;
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* --- Single post page ------------------------------------------ */
.post-header {
  position: relative;
  padding: 60px 24px 32px;
  text-align: center;
  background:
    radial-gradient(ellipse at 50% 0%, rgba(86,156,214,0.06) 0%, transparent 60%),
    var(--bg-primary);
}
.post-header.has-thumbnail {
  background: linear-gradient(to bottom, rgba(0,0,0,0.55), rgba(0,0,0,0.7)),
    var(--post-thumb) center / cover no-repeat;
}
.post-header.has-thumbnail::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse at 50% 0%, rgba(86,156,214,0.25) 0%, transparent 60%);
  pointer-events: none;
}

.post-header h1 {
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  font-weight: 800;
  margin-bottom: 16px;
  letter-spacing: -0.02em;
}

.post-header-meta {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-bottom: 24px;
  flex-wrap: wrap;
}

.post-header-meta .separator { color: var(--border); }

.post-hero-image {
  max-width: 900px;
  margin: 0 auto;
  border-radius: var(--radius);
  border: 1px solid var(--border);
}

/* --- Post content ---------------------------------------------- */
.post-content {
  max-width: 780px;
  margin: 0 auto;
  padding: 48px 24px 64px;
}

.post-content h2 {
  font-size: 1.5rem;
  font-weight: 700;
  margin: 48px 0 16px;
  color: var(--accent-teal);
  letter-spacing: -0.01em;
}

.post-content h3 {
  font-size: 1.2rem;
  font-weight: 600;
  margin: 32px 0 12px;
  color: var(--accent-yellow);
}

.post-content p { margin-bottom: 18px; }

.post-content ul, .post-content ol {
  margin: 0 0 18px 24px;
}

.post-content li { margin-bottom: 6px; }

.post-content img {
  border-radius: var(--radius);
  border: 1px solid var(--border);
  margin: 24px 0;
}

.post-content code {
  font-family: var(--font-mono);
  background: var(--bg-code);
  padding: 2px 6px;
  border-radius: 3px;
  font-size: 0.88em;
  color: var(--accent-orange);
}

.post-content pre {
  background: var(--bg-code);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  overflow-x: auto;
  margin: 24px 0;
}

.post-content pre code {
  background: none;
  padding: 0;
  color: var(--text-primary);
}

.post-content blockquote {
  border-left: 3px solid var(--accent-blue);
  padding: 12px 20px;
  margin: 24px 0;
  background: rgba(86,156,214,0.05);
  border-radius: 0 var(--radius) var(--radius) 0;
  color: var(--text-secondary);
}

.post-content a { border-bottom: 1px solid rgba(86,156,214,0.3); }
.post-content a:hover { border-bottom-color: var(--accent-blue); }

/* --- Gallery --------------------------------------------------- */
.gallery-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 24px;
  padding: 48px 0 64px;
}

.gallery-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: border-color var(--transition), transform var(--transition), box-shadow var(--transition);
}

.gallery-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0,0,0,0.3);
}

.gallery-card-thumb {
  width: 100%;
  aspect-ratio: 16/9;
  object-fit: cover;
  background: var(--bg-secondary);
}

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

.gallery-card-title {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 6px;
}

.gallery-card-title a { color: var(--text-primary); }
.gallery-card-title a:hover { color: var(--accent-teal); }

.gallery-card-desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

/* --- Gallery sub-page ------------------------------------------ */
.gallery-feature { padding: 48px 0 64px; }

.gallery-feature h1 {
  font-size: clamp(1.8rem, 4vw, 2.4rem);
  font-weight: 800;
  margin-bottom: 8px;
}

.gallery-feature .feature-subtitle {
  color: var(--text-secondary);
  margin-bottom: 40px;
  font-size: 1.1rem;
}

.feature-section { margin-bottom: 48px; }

.feature-section h2 {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--accent-teal);
  margin-bottom: 12px;
}

.feature-section p {
  color: var(--text-secondary);
  margin-bottom: 16px;
  max-width: 780px;
}

.feature-media {
  border-radius: var(--radius);
  border: 1px solid var(--border);
  margin-top: 16px;
}

/* --- Home sections --------------------------------------------- */
.home-section {
  padding: 64px 0;
  border-top: 1px solid var(--border);
}

.home-section .section-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  margin-bottom: 32px;
  flex-wrap: wrap;
  gap: 12px;
}

.view-all {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--accent-blue);
}
.view-all:hover { color: var(--accent-teal); }

/* --- Footer ---------------------------------------------------- */
.site-footer {
  margin-top: auto;
  border-top: 1px solid var(--border);
  background: var(--bg-secondary);
  padding: 32px 24px;
  text-align: center;
}

.site-footer p {
  color: var(--text-muted);
  font-size: 0.85rem;
}

.footer-links {
  display: flex;
  gap: 20px;
  justify-content: center;
  margin-bottom: 16px;
  list-style: none;
}

.footer-links a {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

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

/* --- Search box ------------------------------------------------ */
.search-box {
  display: flex;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}

.search-box input {
  flex: 1;
  padding: 8px 12px;
  background: var(--bg-primary);
  border: none;
  color: var(--text-primary);
  font-size: 0.9rem;
  outline: none;
}

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

.search-box button {
  padding: 8px 14px;
  background: var(--bg-card);
  border: none;
  border-left: 1px solid var(--border);
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 0.9rem;
  transition: color var(--transition);
}
.search-box button:hover { color: var(--accent-blue); }

/* --- Page header (for blog list, gallery list) ----------------- */
.page-header {
  padding: 48px 24px 0;
  text-align: center;
}

.page-header h1 {
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  font-weight: 800;
  margin-bottom: 8px;
}

.page-header p {
  color: var(--text-secondary);
  max-width: 550px;
  margin: 0 auto;
}

/* --- Breadcrumbs ----------------------------------------------- */
.breadcrumbs {
  padding: 16px 0;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.breadcrumbs a { color: var(--text-secondary); }
.breadcrumbs a:hover { color: var(--accent-blue); }
.breadcrumbs .sep { margin: 0 6px; }

/* --- Placeholder thumb (when no image) ------------------------- */
.thumb-placeholder {
  width: 100%;
  aspect-ratio: 16/9;
  background: linear-gradient(135deg, var(--bg-secondary), var(--bg-card));
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  font-size: 2.5rem;
}

/* --- Utility --------------------------------------------------- */
.text-teal   { color: var(--accent-teal); }
.text-blue   { color: var(--accent-blue); }
.text-yellow { color: var(--accent-yellow); }
.text-orange { color: var(--accent-orange); }
.text-green  { color: var(--accent-green); }
.text-purple { color: var(--accent-purple); }

.mt-0 { margin-top: 0; }

/* --- Sub-gallery (embedded image grids) ------------------------ */
.sub-gallery {
  margin: 24px 0 40px;
}

.sub-gallery-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 16px;
}

.sub-gallery-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  cursor: pointer;
  transition: border-color var(--transition), transform var(--transition), box-shadow var(--transition);
}

.sub-gallery-item:hover {
  border-color: var(--border-hover);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0,0,0,0.3);
}

.sub-gallery-item img,
.sub-gallery-item video {
  width: 100%;
  aspect-ratio: 16/9;
  object-fit: cover;
  display: block;
  background: var(--bg-secondary);
}

.sub-gallery-item .caption {
  padding: 10px 14px;
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.sub-gallery-placeholder {
  width: 100%;
  aspect-ratio: 16/9;
  background: linear-gradient(135deg, var(--bg-secondary), var(--bg-card));
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  font-size: 0.85rem;
}

.sub-gallery-show-all {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-top: 12px;
  padding: 6px 16px;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--accent-blue);
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  transition: border-color var(--transition), background var(--transition);
}

.sub-gallery-show-all:hover {
  border-color: var(--accent-blue);
  background: rgba(86,156,214,0.08);
}

.sub-gallery-item.hidden { display: none; }

/* --- Lightbox -------------------------------------------------- */
.lightbox {
  position: fixed;
  inset: 0;
  z-index: 1000;
  background: rgba(0,0,0,0.85);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: zoom-out;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s ease;
}

.lightbox.visible { opacity: 1; pointer-events: auto; }

.lightbox img,
.lightbox video {
  max-width: 90vw;
  max-height: 90vh;
  border-radius: var(--radius);
  box-shadow: 0 16px 48px rgba(0,0,0,0.5);
}

.lightbox-caption {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  color: var(--text-secondary);
  font-size: 0.9rem;
  background: var(--bg-secondary);
  padding: 8px 20px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  white-space: nowrap;
}

/* --- No-results message ---------------------------------------- */
.no-results {
  grid-column: 1 / -1;
  text-align: center;
  padding: 48px 0;
  color: var(--text-muted);
  font-size: 1rem;
}