/* ==========================================================================
   Design System & Theme Tokens - thegosset.com
   ========================================================================== */

:root {
  /* Light Mode Palette */
  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-tertiary: #f1f5f9;
  --bg-card: #ffffff;
  --bg-card-hover: #f8fafc;
  --border-color: #e2e8f0;
  --border-hover: #cbd5e1;

  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #64748b;

  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --accent-light: #eff6ff;
  --accent-border: #bfdbfe;

  --code-bg: #0f172a;
  --code-text: #f8fafc;
  --inline-code-bg: #f1f5f9;
  --inline-code-text: #0f172a;

  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.08), 0 2px 4px -2px rgb(0 0 0 / 0.06);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.08), 0 4px 6px -4px rgb(0 0 0 / 0.05);

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-full: 9999px;

  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --font-mono: 'JetBrains Mono', SFMono-Regular, Menlo, Monaco, Consolas, monospace;

  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s ease;
}

[data-theme="dark"] {
  /* Dark Mode Palette */
  --bg-primary: #0b0f19;
  --bg-secondary: #111827;
  --bg-tertiary: #1f2937;
  --bg-card: #111827;
  --bg-card-hover: #172033;
  --border-color: #1f293d;
  --border-hover: #374151;

  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;

  --accent: #3b82f6;
  --accent-hover: #60a5fa;
  --accent-light: rgba(59, 130, 246, 0.12);
  --accent-border: rgba(59, 130, 246, 0.3);

  --code-bg: #030712;
  --code-text: #f3f4f6;
  --inline-code-bg: #1f2937;
  --inline-code-text: #93c5fd;

  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.3);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.4);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.5);
}

/* ==========================================================================
   Base & Reset
   ========================================================================== */

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

html {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-primary);
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  transition: background-color var(--transition-normal), color var(--transition-normal);
}

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

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

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

/* ==========================================================================
   Layout Containers
   ========================================================================== */

.container {
  width: 100%;
  max-width: 1040px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.container-narrow {
  width: 100%;
  max-width: 760px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ==========================================================================
   Header & Navigation
   ========================================================================== */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background-color: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  padding-top: env(safe-area-inset-top, 0);
  transition: background-color var(--transition-normal), border-color var(--transition-normal);
}

[data-theme="dark"] .site-header {
  background-color: rgba(11, 15, 25, 0.85);
}

.nav-wrapper {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 4rem;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--text-primary);
}

.brand-dot {
  width: 9px;
  height: 9px;
  border-radius: var(--radius-full);
  background-color: var(--accent);
  box-shadow: 0 0 10px var(--accent);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.75rem;
  list-style: none;
}

.nav-link {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: color var(--transition-fast);
}

.nav-link:hover, .nav-link.active {
  color: var(--text-primary);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.theme-toggle-btn {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  width: 2.25rem;
  height: 2.25rem;
  border-radius: var(--radius-md);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background-color var(--transition-fast), border-color var(--transition-fast);
}

.theme-toggle-btn:hover {
  background: var(--border-color);
}

.theme-toggle-btn svg {
  width: 1.1rem;
  height: 1.1rem;
  fill: currentColor;
}

/* Mobile Menu */
.mobile-menu-btn {
  display: none;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  width: 2.25rem;
  height: 2.25rem;
  border-radius: var(--radius-md);
  cursor: pointer;
  align-items: center;
  justify-content: center;
  padding: 0;
  transition: background-color var(--transition-fast), border-color var(--transition-fast);
}

.mobile-menu-btn:hover {
  background: var(--border-color);
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    flex-direction: column;
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    padding: 1.5rem;
    gap: 1.25rem;
  }

  .nav-links.open {
    display: flex;
  }

  .mobile-menu-btn {
    display: flex;
  }
}

/* ==========================================================================
   Main Content Layout
   ========================================================================== */

main {
  flex: 1;
  padding-bottom: 5rem;
}

/* Hero Section */
.hero-section {
  padding-top: 4.5rem;
  padding-bottom: 3.5rem;
}

.hero-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--accent);
  background: var(--accent-light);
  border: 1px solid var(--accent-border);
  padding: 0.35rem 0.85rem;
  border-radius: var(--radius-full);
  margin-bottom: 1.5rem;
}

.hero-title {
  font-size: 2.75rem;
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -0.03em;
  margin-bottom: 1.25rem;
  color: var(--text-primary);
}

.hero-bio {
  font-size: 1.2rem;
  color: var(--text-secondary);
  max-width: 650px;
  line-height: 1.7;
}

.hero-links {
  display: flex;
  gap: 1rem;
  margin-top: 1.75rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 600;
  font-size: 0.95rem;
  padding: 0.65rem 1.25rem;
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
  cursor: pointer;
}

.btn-primary {
  background: var(--accent);
  color: #ffffff;
  border: 1px solid transparent;
}

.btn-primary:hover {
  background: var(--accent-hover);
  color: #ffffff;
  transform: translateY(-1px);
}

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

.btn-secondary:hover {
  background: var(--border-color);
  color: var(--text-primary);
}

/* Section Common */
.section-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 1.75rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--border-color);
}

.section-title {
  font-size: 1.45rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

.section-link {
  font-size: 0.9rem;
  font-weight: 600;
}

/* ==========================================================================
   Featured Project Card (FI Portal)
   ========================================================================== */

.featured-project {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  margin-bottom: 3.5rem;
  display: grid;
  grid-template-columns: 1.3fr 1fr;
  gap: 2rem;
  align-items: center;
  box-shadow: var(--shadow-sm);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.featured-project:hover {
  border-color: var(--accent);
  box-shadow: var(--shadow-md);
}

.project-badge {
  display: inline-block;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 0.75rem;
}

.project-title {
  font-size: 1.65rem;
  font-weight: 700;
  margin-bottom: 0.85rem;
}

.project-desc {
  color: var(--text-secondary);
  font-size: 1rem;
  line-height: 1.6;
  margin-bottom: 1.25rem;
}

.project-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
}

.tag-badge {
  font-size: 0.75rem;
  font-weight: 600;
  font-family: var(--font-mono);
  background: var(--bg-tertiary);
  color: var(--text-secondary);
  padding: 0.25rem 0.6rem;
  border-radius: var(--radius-sm);
}

.project-visual {
  background: linear-gradient(135deg, rgba(37, 99, 235, 0.1), rgba(16, 185, 129, 0.1));
  border: 1px dashed var(--accent-border);
  border-radius: var(--radius-md);
  height: 100%;
  min-height: 180px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 1.5rem;
}

.visual-icon {
  font-size: 2.5rem;
  margin-bottom: 0.5rem;
}

.visual-label {
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--text-primary);
}

.visual-sub {
  font-size: 0.8rem;
  color: var(--text-muted);
}

@media (max-width: 768px) {
  .featured-project {
    grid-template-columns: 1fr;
  }
}

/* ==========================================================================
   Lab & Interactive Experiments Grid
   ========================================================================== */

.lab-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.25rem;
  margin-bottom: 3.5rem;
}

.lab-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.4rem;
  display: flex;
  flex-direction: column;
  transition: transform var(--transition-fast), border-color var(--transition-fast);
}

.lab-card:hover {
  transform: translateY(-2px);
  border-color: var(--accent);
}

.lab-card-title {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}

.lab-card-desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 1rem;
  flex: 1;
}

.lab-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.85rem;
  font-weight: 600;
}

/* ==========================================================================
   Article Cards / Blog Feed
   ========================================================================== */

.posts-list {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.post-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.post-card:hover {
  border-color: var(--accent);
  box-shadow: var(--shadow-sm);
}

.post-card-meta {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.post-card-title {
  font-size: 1.3rem;
  font-weight: 700;
  line-height: 1.35;
  color: var(--text-primary);
}

.post-card-title a {
  color: inherit;
}

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

.post-card-excerpt {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.6;
}

.post-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 0.25rem;
}

.post-tags {
  display: flex;
  gap: 0.4rem;
}

/* ==========================================================================
   Article Page (Reading Layout & Prose)
   ========================================================================== */

.post-header {
  padding: 3rem 0 2rem;
  border-bottom: 1px solid var(--border-color);
  margin-bottom: 2.5rem;
}

.breadcrumbs {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 1.25rem;
}

.post-headline {
  font-size: 2.5rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.2;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.post-meta-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1.25rem;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.post-featured-image {
  margin: 2rem 0;
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--border-color);
}

/* Article Body Typography (Prose) */
.prose {
  font-size: 1.08rem;
  line-height: 1.8;
  color: var(--text-primary);
}

.prose p {
  margin-bottom: 1.5rem;
}

.prose h2 {
  font-size: 1.65rem;
  font-weight: 700;
  margin: 2.5rem 0 1rem;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

.prose h3 {
  font-size: 1.3rem;
  font-weight: 600;
  margin: 2rem 0 0.75rem;
  color: var(--text-primary);
}

.prose ul, .prose ol {
  margin: 0 0 1.5rem 1.75rem;
}

.prose li {
  margin-bottom: 0.5rem;
}

.prose blockquote {
  border-left: 4px solid var(--accent);
  background: var(--bg-secondary);
  padding: 1rem 1.25rem;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin: 1.75rem 0;
  color: var(--text-secondary);
  font-style: italic;
}

.prose img {
  border-radius: var(--radius-sm);
  margin: 2rem auto;
  border: 1px solid var(--border-color);
}

/* Inline Code */
.prose code:not(pre code) {
  font-family: var(--font-mono);
  font-size: 0.88em;
  background: var(--inline-code-bg);
  color: var(--inline-code-text);
  padding: 0.2em 0.4em;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
}

/* Code Blocks & Copy Button */
.code-wrapper {
  position: relative;
  margin: 1.75rem 0;
  border-radius: var(--radius-md);
  overflow: hidden;
  background: var(--code-bg);
  border: 1px solid var(--border-color);
}

.code-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.5rem 1rem;
  background: rgba(255, 255, 255, 0.05);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: #94a3b8;
}

.copy-btn {
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.2);
  color: #e2e8f0;
  padding: 0.2rem 0.55rem;
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.copy-btn:hover {
  background: rgba(255, 255, 255, 0.15);
}

.prose pre {
  margin: 0;
  padding: 1.25rem;
  overflow-x: auto;
  background: var(--code-bg);
  color: var(--code-text);
  font-family: var(--font-mono);
  font-size: 0.9rem;
  line-height: 1.6;
}

/* Post Author Footer */
.author-card {
  margin-top: 4rem;
  padding: 2rem;
  border-radius: var(--radius-md);
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.author-avatar {
  width: 72px;
  height: 72px;
  border-radius: var(--radius-full);
  object-fit: cover;
  border: 2px solid var(--accent);
}

.author-name {
  font-weight: 700;
  font-size: 1.15rem;
  margin-bottom: 0.25rem;
}

.author-bio {
  font-size: 0.95rem;
  color: var(--text-secondary);
}

/* ==========================================================================
   Site Footer
   ========================================================================== */

.site-footer {
  border-top: 1px solid var(--border-color);
  padding: 3rem 0;
  margin-top: auto;
  background: var(--bg-secondary);
}

.footer-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
  text-align: center;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.footer-links {
  display: flex;
  gap: 1.5rem;
}

/* ==========================================================================
   Mobile Responsive Overrides
   ========================================================================== */

@media (max-width: 768px) {
  .container,
  .container-narrow {
    padding-left: 1.25rem;
    padding-right: 1.25rem;
  }

  .site-header {
    padding-top: max(0.5rem, env(safe-area-inset-top, 0px));
  }

  .nav-wrapper {
    height: 3.75rem;
  }

  .hero-section {
    padding-top: 3.25rem;
    padding-bottom: 2.25rem;
  }

  .hero-title {
    font-size: clamp(1.85rem, 7vw, 2.35rem);
    line-height: 1.22;
    margin-bottom: 1.15rem;
  }

  .hero-bio {
    font-size: 1.05rem;
    line-height: 1.65;
  }

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