/* Shared Layout - Singapore AI Theme */
/* Depends on public/m3-tokens.css */

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

body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  background-color: var(--md-sys-color-surface);
  color: var(--md-sys-color-on-surface);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* ═══ NAVIGATION ═══ */
.nav-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.9); /* Default light */
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--md-sys-color-outline-variant);
  transition: all 0.3s ease;
}

[data-theme="dark"] .nav-header {
  background: rgba(15, 23, 42, 0.9);
}

.nav-container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
  height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-brand {
  font-family: 'Inter', sans-serif;
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--md-sys-color-on-surface);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 12px;
}

.nav-logo {
  width: 32px;
  height: 32px;
  background: linear-gradient(135deg, var(--md-sys-color-primary), var(--md-sys-color-accent-cyan));
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 800;
  font-size: 14px;
}

.nav-menu {
  display: flex;
  gap: 32px;
  list-style: none;
}

.nav-link {
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--md-sys-color-on-surface-secondary);
  text-decoration: none;
  transition: color 0.2s ease;
  padding: 8px 0;
  position: relative;
}

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

.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--md-sys-color-primary);
  border-radius: 2px;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 16px;
}

.menu-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--md-sys-color-on-surface);
  font-size: 1.5rem;
  cursor: pointer;
}

/* Mobile Nav */
@media (max-width: 768px) {
  .nav-menu {
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--md-sys-color-surface);
    flex-direction: column;
    padding: 24px;
    gap: 0;
    transform: translateX(100%);
    transition: transform 0.3s ease;
    border-top: 1px solid var(--md-sys-color-outline-variant);
  }
  
  .nav-menu.open {
    transform: translateX(0);
  }
  
  .nav-link {
    font-size: 1.125rem;
    padding: 16px 0;
    border-bottom: 1px solid var(--md-sys-color-outline-variant);
    display: block;
  }
  
  .menu-toggle {
    display: block;
  }
}

/* ═══ FOOTER ═══ */
.site-footer {
  background: var(--md-sys-color-surface-container-low);
  border-top: 1px solid var(--md-sys-color-outline-variant);
  padding: 60px 24px 30px;
  margin-top: auto;
}

.footer-container {
  max-width: 1280px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 40px;
}

.footer-brand h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 16px;
  color: var(--md-sys-color-on-surface);
}

.footer-text {
  color: var(--md-sys-color-on-surface-secondary);
  font-size: 0.875rem;
  line-height: 1.6;
  max-width: 300px;
}

.footer-col h4 {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--md-sys-color-on-surface);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 20px;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-link {
  color: var(--md-sys-color-on-surface-secondary);
  text-decoration: none;
  font-size: 0.9375rem;
  transition: color 0.2s;
}

.footer-link:hover {
  color: var(--md-sys-color-primary);
}

.footer-bottom {
  max-width: 1280px;
  margin: 60px auto 0;
  padding-top: 24px;
  border-top: 1px solid var(--md-sys-color-outline-variant);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
  color: var(--md-sys-color-on-surface-tertiary);
  font-size: 0.875rem;
}

/* ═══ UTILITIES (Glass Cards & Typography) ═══ */
.main-content {
  padding-top: 72px; /* Nav height */
  flex: 1;
}

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

/* Glass Card - Key Design Element */
.glass-card {
  background: var(--glass-bg);
  backdrop-filter: blur(var(--glass-blur));
  -webkit-backdrop-filter: blur(var(--glass-blur));
  border: 1px solid var(--glass-border);
  box-shadow: var(--glass-shadow);
  border-radius: var(--md-sys-shape-corner-extra-large);
  transition: transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
}

.glass-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 40px -8px rgba(0, 0, 0, 0.15);
  border-color: var(--md-sys-color-primary-container);
}

/* Typography Helpers */
.gradient-text {
  background: linear-gradient(135deg, var(--md-sys-color-primary), var(--md-sys-color-accent-cyan));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.section-title {
  font-size: 2.25rem; /* Display Small */
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--md-sys-color-on-surface);
  margin-bottom: 1.5rem;
}

.section-sub {
  font-size: 1.125rem;
  color: var(--md-sys-color-on-surface-secondary);
  max-width: 65ch;
  margin-bottom: 2.5rem;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 24px;
  border-radius: var(--md-sys-shape-corner-full);
  font-weight: 600;
  text-decoration: none;
  transition: all 0.2s ease;
  cursor: pointer;
  border: none;
  font-size: 0.9375rem;
}

.btn-primary {
  background: var(--md-sys-color-primary);
  color: var(--md-sys-color-on-primary);
  box-shadow: 0 4px 12px rgba(2, 132, 199, 0.25); /* Shadow color based on primary */
}

.btn-primary:hover {
  background: color-mix(in srgb, var(--md-sys-color-primary) 90%, black);
  transform: translateY(-1px);
}

.btn-secondary {
  background: var(--md-sys-color-surface-container-high);
  color: var(--md-sys-color-on-surface);
  border: 1px solid var(--md-sys-color-outline-variant);
}

.btn-secondary:hover {
  background: var(--md-sys-color-surface-container-highest);
  border-color: var(--md-sys-color-outline);
}

/* Grid System */
.grid-3 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 24px;
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
  gap: 32px;
}

/* ═══ DOCS LAYOUT (Google Docs Style) ═══ */
/* Applied to blog detail pages */
.docs-layout {
  display: grid;
  grid-template-columns: 260px minmax(0, 1fr) 240px; /* Left Sidebar | Content | Right Sidebar */
  max-width: 1440px;
  margin: 0 auto;
  min-height: calc(100vh - 72px); /* Subtract Header height */
  margin-top: 72px; /* Offset fixed header */
}

/* Common Sidebar Styles */
.docs-sidebar {
  position: sticky;
  top: 72px;
  height: calc(100vh - 72px);
  overflow-y: auto;
  padding: 24px 16px;
  font-size: 0.875rem;
}

/* Left Sidebar - Global Nav */
.docs-sidebar-left {
  border-right: 1px solid var(--md-sys-color-outline-variant);
  background-color: var(--md-sys-color-surface);
  z-index: 10;
}

.docs-nav-tree ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

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

.docs-nav-item {
  display: block;
  padding: 6px 12px;
  color: var(--md-sys-color-on-surface-secondary);
  text-decoration: none;
  border-radius: 4px;
  transition: all 0.2s ease;
  font-weight: 500;
}

.docs-nav-item:hover {
  background-color: var(--md-sys-color-surface-container-high);
  color: var(--md-sys-color-on-surface);
}

.docs-nav-item.active {
  background-color: var(--md-sys-color-primary-container);
  color: var(--md-sys-color-on-primary-container);
  font-weight: 600;
}

.docs-nav-group {
  margin-left: 12px;
  margin-top: 4px;
  border-left: 1px solid var(--md-sys-color-outline-variant);
  padding-left: 4px;
}

.docs-nav-header {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--md-sys-color-on-surface-tertiary);
  font-weight: 700;
  margin: 16px 0 8px 12px;
}

/* Right Sidebar - Page TOC */
.docs-sidebar-right {
  border-left: 1px solid var(--md-sys-color-outline-variant);
  padding-right: 24px;
  background-color: var(--md-sys-color-surface);
  z-index: 10;
}

.docs-toc h3 {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--md-sys-color-on-surface);
  font-weight: 700;
  margin: 0 0 12px;
}

.docs-toc ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.docs-toc li {
  margin-bottom: 8px;
}

.docs-toc a {
  color: var(--md-sys-color-on-surface-secondary);
  text-decoration: none;
  display: block;
  font-size: 0.8125rem;
  line-height: 1.4;
  border-left: 2px solid transparent;
  padding-left: 12px;
  transition: all 0.2s ease;
}

.docs-toc a:hover {
  color: var(--md-sys-color-primary);
  border-left-color: var(--md-sys-color-outline-variant);
}

.docs-toc a.active {
  color: var(--md-sys-color-primary);
  border-left-color: var(--md-sys-color-primary);
  font-weight: 500;
}

/* Main Content Area */
.docs-content {
  padding: 40px 48px 80px;
  max-width: 860px; /* Constrain reading width */
  margin: 0 auto;
  min-width: 0; /* Important for grid/flex child shrinking */
  width: 100%; /* Ensure it fills the grid track */
}

/* Ensure all images in docs fit the container */
.docs-content img, 
.content-img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* Typography Overrides for Docs */
.docs-content h1,
.docs-content h2,
.docs-content h3,
.docs-content h4,
.docs-content h5,
.docs-content h6 {
  scroll-margin-top: 100px;
}

.docs-content h1 {
  font-size: 2.5rem;
  margin-bottom: 16px;
  line-height: 1.2;
}

.docs-content .subtitle {
  font-size: 1.25rem;
  color: var(--md-sys-color-on-surface-secondary);
  margin-bottom: 40px;
  font-weight: 300;
  line-height: 1.5;
}

.docs-content h2 {
  font-size: 1.75rem;
  margin-top: 48px;
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--md-sys-color-outline-variant);
}

.docs-content h3 {
  font-size: 1.25rem;
  margin-top: 32px;
  margin-bottom: 12px;
}

/* Responsive */
@media (max-width: 1200px) {
  .docs-layout {
    grid-template-columns: 240px minmax(0, 1fr); /* Hide Right Sidebar */
  }
  .docs-sidebar-right {
    display: none;
  }
}

@media (max-width: 768px) {
  /* Layout Optimizations */
  .docs-layout {
    display: block; /* Stack layout */
    margin-top: 56px;
  }
  .docs-sidebar-left {
    display: none; /* Hide Left Sidebar on mobile (use hamburger) */
  }
  .docs-content {
    padding: 24px 20px; /* Reduced padding */
  }
  
  /* Shared Mobile Typography Tightening */
  .section-title {
    font-size: 1.75rem;
    margin-bottom: 1rem;
  }
  
  .section-sub {
    font-size: 1rem;
    margin-bottom: 1.5rem; /* Reduced from 2.5rem */
  }
  
  .site-footer {
    padding: 40px 20px 24px;
  }
  
  .footer-container {
    gap: 32px;
  }
  
  .grid-3, .grid-2 {
    gap: 16px; /* Reduced from 24/32px */
  }
  
  /* Blog Card Mobile Tweak */
  .blog-card {
    padding: 20px;
  }
}