/* ==========================================================================
   TerraSpatial Unified Geospatial Platform - Modern Core Stylesheet
   Client-Side Geospatial, Remote Sensing, Spatial Solar PV & GeoAI Engine
   ========================================================================== */

:root {
  /* Color Palette: Deep Space & Cyber Geomatics */
  --bg-primary: #070b14;
  --bg-secondary: #0d1322;
  --bg-card: #121a2d;
  --bg-card-hover: #17223b;
  --bg-card-elevated: #1a2642;
  --bg-input: #0a0f1d;
  --bg-input-focus: #0f172a;
  --bg-code: #060a12;

  /* Accent Color System */
  --color-emerald-light: #34d399;
  --color-emerald-base: #10b981;
  --color-emerald-dark: #059669;
  --color-cyan-bright: #38bdf8;
  --color-cyan-base: #0ea5e9;
  --color-cyan-dark: #0284c7;
  --color-amber-light: #fbbf24;
  --color-amber-base: #f59e0b;
  --color-amber-dark: #d97706;
  --color-purple-light: #c084fc;
  --color-purple-base: #a855f7;
  --color-purple-dark: #7e22ce;
  --color-indigo-light: #818cf8;
  --color-rose-light: #fb7185;

  /* Soft Ambient Alpha Backdrops */
  --bg-accent-soft: rgba(16, 185, 129, 0.12);
  --bg-cyan-soft: rgba(14, 165, 233, 0.12);
  --bg-amber-soft: rgba(245, 158, 11, 0.12);
  --bg-purple-soft: rgba(168, 85, 247, 0.12);

  /* Borders & Dividers */
  --border-subtle: rgba(255, 255, 255, 0.08);
  --border-medium: rgba(255, 255, 255, 0.14);
  --border-focus: #38bdf8;
  --border-accent: #10b981;
  --border-amber: #f59e0b;
  --border-purple: #a855f7;

  /* Typography Colors */
  --color-text-primary: #f8fafc;
  --color-text-secondary: #94a3b8;
  --color-text-muted: #64748b;
  --color-text-dim: #475569;
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  --text-accent: #34d399;
  --text-cyan: #38bdf8;
  --text-amber: #fbbf24;

  /* Typography Stack */
  --font-sans: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;

  /* Spacing & Radii */
  --radius-xs: 4px;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-xl: 24px;

  /* Shadows & Glows */
  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 6px 18px rgba(0, 0, 0, 0.5), 0 0 0 1px var(--border-subtle);
  --shadow-lg: 0 16px 36px rgba(0, 0, 0, 0.6), 0 0 0 1px var(--border-medium);
  --shadow-glow-cyan: 0 0 24px rgba(14, 165, 233, 0.25);
  --shadow-glow-emerald: 0 0 24px rgba(16, 185, 129, 0.25);
  --shadow-glow-purple: 0 0 24px rgba(168, 85, 247, 0.25);

  --max-width: 1240px;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  background-color: var(--bg-primary);
  color: var(--color-text-primary);
  font-family: var(--font-sans);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background-color: var(--bg-primary);
  background-image: 
    radial-gradient(ellipse 80% 50% at 50% -20%, rgba(14, 165, 233, 0.12), transparent 70%),
    radial-gradient(ellipse 60% 40% at 90% 100%, rgba(16, 185, 129, 0.08), transparent 70%),
    linear-gradient(to right, rgba(255, 255, 255, 0.02) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255, 255, 255, 0.02) 1px, transparent 1px);
  background-size: 100% 100%, 100% 100%, 64px 64px, 64px 64px;
  background-position: center top, right bottom, 0 0, 0 0;
  color: var(--color-text-primary);
}

a {
  color: var(--color-cyan-bright);
  text-decoration: none;
  transition: all 0.2s ease;
}

a:hover, a:focus {
  color: #7dd3fc;
  text-decoration: none;
}

img, svg {
  vertical-align: middle;
}

/* ==========================================================================
   Global Site Header & Navigation
   ========================================================================== */
.site-header {
  background-color: rgba(7, 11, 20, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-subtle);
  position: sticky;
  top: 0;
  z-index: 1000;
  transition: all 0.25s ease;
}

.site-header::after {
  content: "";
  position: absolute;
  bottom: -1px;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(56, 189, 248, 0.3), rgba(16, 185, 129, 0.3), transparent);
}

.nav-container, .header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0.85rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
}

.brand-logo, .brand-link {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 1.25rem;
  font-weight: 700;
  color: #ffffff !important;
  text-decoration: none !important;
  letter-spacing: -0.02em;
}

.brand-icon, .brand-logo-icon {
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, #10b981 0%, #0ea5e9 50%, #6366f1 100%);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #ffffff;
  font-weight: 800;
  font-size: 1.1rem;
  box-shadow: 0 4px 12px rgba(14, 165, 233, 0.35);
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.nav-links, .main-nav {
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.nav-links a, .nav-link {
  padding: 0.45rem 0.85rem;
  border-radius: var(--radius-sm);
  color: var(--color-text-secondary);
  font-size: 0.92rem;
  font-weight: 500;
  transition: all 0.2s ease;
  border: 1px solid transparent;
}

.nav-links a:hover, .nav-link:hover, .nav-links a:focus, .nav-link:focus {
  color: #ffffff;
  background-color: rgba(255, 255, 255, 0.05);
  border-color: var(--border-subtle);
}

.nav-links a.active, .nav-link.active {
  color: #ffffff;
  background: rgba(14, 165, 233, 0.12);
  border-color: rgba(14, 165, 233, 0.35);
  box-shadow: 0 0 12px rgba(14, 165, 233, 0.15);
}

.nav-tag-badge {
  font-size: 0.7rem;
  padding: 0.15rem 0.45rem;
  border-radius: 9999px;
  background: rgba(168, 85, 247, 0.2);
  color: var(--color-purple-light);
  border: 1px solid rgba(168, 85, 247, 0.4);
  font-weight: 600;
  margin-left: 0.35rem;
  vertical-align: middle;
}

.menu-toggle {
  display: none;
  background: transparent;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  color: var(--color-text-primary);
  padding: 0.45rem;
  cursor: pointer;
  transition: all 0.2s ease;
}

.menu-toggle:hover {
  background-color: var(--bg-card);
  border-color: var(--border-medium);
}

@media (max-width: 960px) {
  .menu-toggle {
    display: block;
  }
  .nav-links, .main-nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background-color: rgba(13, 19, 34, 0.98);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-medium);
    padding: 1.25rem;
    flex-direction: column;
    align-items: stretch;
    gap: 0.5rem;
    box-shadow: var(--shadow-lg);
  }
  .nav-links.active, .main-nav.active {
    display: flex;
  }
}

/* ==========================================================================
   Breadcrumb Bar & Sub-Navigation
   ========================================================================== */
.breadcrumb-trail, .breadcrumb-inner {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem;
  font-size: 0.85rem;
  color: var(--color-text-muted);
  margin-bottom: 1.25rem;
}

.breadcrumb-trail a, .breadcrumb-inner a {
  color: var(--color-text-secondary);
}

.breadcrumb-trail a:hover, .breadcrumb-inner a:hover {
  color: var(--color-cyan-bright);
}

.breadcrumb-trail span, .breadcrumb-current {
  color: var(--color-emerald-light);
  font-weight: 500;
}

/* ==========================================================================
   Main Content Layout & Hero Headings
   ========================================================================== */
.main-content, main.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 2.5rem 1.5rem 5rem 1.5rem;
  flex: 1;
  width: 100%;
}

.page-header, .hero-head {
  margin-bottom: 2.5rem;
}

.page-title, h1.hero-title {
  font-size: clamp(2rem, 4vw, 2.75rem);
  line-height: 1.2;
  font-weight: 800;
  color: #ffffff;
  margin-bottom: 0.85rem;
  letter-spacing: -0.03em;
  background: linear-gradient(135deg, #ffffff 60%, #94a3b8 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.page-subtitle, p.hero-subtitle {
  font-size: 1.15rem;
  line-height: 1.65;
  color: var(--color-text-secondary);
  max-width: 920px;
}

/* ==========================================================================
   Interactive Tool Cards
   ========================================================================== */
.tool-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 2.25rem;
  margin-bottom: 3rem;
  box-shadow: var(--shadow-md);
  position: relative;
  overflow: hidden;
  backdrop-filter: blur(12px);
  transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

.tool-card:hover {
  border-color: rgba(56, 189, 248, 0.3);
  box-shadow: var(--shadow-lg), var(--shadow-glow-cyan);
}

.tool-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, #10b981, #0ea5e9, #a855f7);
}

.tool-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 1.75rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border-subtle);
}

.tool-card-title {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 1.25rem;
  font-weight: 700;
  color: #ffffff;
  letter-spacing: -0.01em;
}

.tool-card-title svg {
  color: var(--color-cyan-bright);
}

/* Form Controls & Inputs */
.form-group {
  margin-bottom: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
}

.form-group label {
  font-size: 0.88rem;
  font-weight: 600;
  color: #e2e8f0;
  letter-spacing: 0.01em;
}

.form-control {
  width: 100%;
  padding: 0.75rem 1rem;
  background-color: var(--bg-input);
  border: 1px solid var(--border-medium);
  border-radius: var(--radius-sm);
  color: #ffffff;
  font-size: 0.95rem;
  font-family: var(--font-sans);
  transition: all 0.2s ease;
  outline: none;
}

.form-control:focus {
  background-color: var(--bg-input-focus);
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px rgba(14, 165, 233, 0.25);
}

select.form-control {
  appearance: none;
  background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%2394a3b8' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3e%3cpolyline points='6 9 12 15 18 9'%3e%3c/polyline%3e%3c/svg%3e");
  background-repeat: no-repeat;
  background-position: right 0.85rem center;
  background-size: 1.1em;
  padding-right: 2.5rem;
  cursor: pointer;
}

textarea.form-control {
  min-height: 110px;
  resize: vertical;
  font-family: var(--font-mono);
  font-size: 0.88rem;
}

.input-grid {
  display: grid;
  gap: 1.25rem;
}

.button-group {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem;
  align-items: center;
}

/* Button System */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.4rem;
  font-size: 0.92rem;
  font-weight: 600;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all 0.2s ease;
  border: 1px solid transparent;
  text-decoration: none !important;
  line-height: 1.2;
}

.btn-primary {
  background: linear-gradient(135deg, #0ea5e9 0%, #0284c7 100%);
  color: #ffffff;
  box-shadow: 0 4px 14px rgba(14, 165, 233, 0.35);
}

.btn-primary:hover {
  background: linear-gradient(135deg, #38bdf8 0%, #0ea5e9 100%);
  box-shadow: 0 6px 20px rgba(14, 165, 233, 0.5);
  transform: translateY(-1px);
  color: #ffffff;
}

.btn-accent {
  background: linear-gradient(135deg, #10b981 0%, #059669 100%);
  color: #ffffff;
  box-shadow: 0 4px 14px rgba(16, 185, 129, 0.35);
}

.btn-accent:hover {
  background: linear-gradient(135deg, #34d399 0%, #10b981 100%);
  box-shadow: 0 6px 20px rgba(16, 185, 129, 0.5);
  transform: translateY(-1px);
  color: #ffffff;
}

.btn-purple {
  background: linear-gradient(135deg, #a855f7 0%, #7e22ce 100%);
  color: #ffffff;
  box-shadow: 0 4px 14px rgba(168, 85, 247, 0.35);
}

.btn-purple:hover {
  background: linear-gradient(135deg, #c084fc 0%, #a855f7 100%);
  box-shadow: 0 6px 20px rgba(168, 85, 247, 0.5);
  transform: translateY(-1px);
  color: #ffffff;
}

.btn-outline {
  background-color: rgba(255, 255, 255, 0.04);
  color: #ffffff;
  border-color: var(--border-medium);
}

.btn-outline:hover {
  background-color: rgba(255, 255, 255, 0.08);
  border-color: #ffffff;
  color: #ffffff;
}

/* ==========================================================================
   Calculation Results Boxes & Feedback
   ========================================================================== */
.result-box {
  background-color: var(--bg-input);
  border: 1px solid var(--border-medium);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  margin-top: 1.5rem;
  position: relative;
  transition: all 0.2s ease;
}

.result-box:hover {
  border-color: var(--border-focus);
}

.result-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.65rem;
}

.result-label {
  font-size: 0.84rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-text-secondary);
}

.result-value {
  font-family: var(--font-mono);
  font-size: 1.65rem;
  font-weight: 700;
  color: #ffffff;
  word-break: break-all;
  margin-bottom: 0.35rem;
}

.field-help {
  font-size: 0.85rem;
  color: var(--color-text-secondary);
}

.copy-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.35rem 0.75rem;
  font-size: 0.78rem;
  font-weight: 600;
  border-radius: var(--radius-xs);
  cursor: pointer;
  background-color: rgba(255, 255, 255, 0.06);
  color: var(--color-text-secondary);
  border: 1px solid var(--border-subtle);
  transition: all 0.2s ease;
}

.copy-btn:hover {
  background-color: var(--bg-card);
  color: #ffffff;
  border-color: var(--border-medium);
}

/* Status Badges */
.status-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 0.25rem 0.65rem;
  border-radius: 9999px;
  background-color: rgba(255, 255, 255, 0.08);
  color: #ffffff;
  border: 1px solid var(--border-subtle);
}

.status-valid {
  background-color: rgba(16, 185, 129, 0.15);
  color: var(--color-emerald-light);
  border-color: rgba(16, 185, 129, 0.35);
}

.status-warning {
  background-color: rgba(245, 158, 11, 0.15);
  color: var(--color-amber-light);
  border-color: rgba(245, 158, 11, 0.35);
}

.status-error {
  background-color: rgba(244, 63, 94, 0.15);
  color: #fb7185;
  border-color: rgba(244, 63, 94, 0.35);
}

/* ==========================================================================
   Hero Metric Summary Cards (4-Column Grid)
   ========================================================================== */
.metric-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.25rem;
  margin: 2.5rem 0;
}

.metric-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
  position: relative;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: all 0.25s ease;
}

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

.metric-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, #0ea5e9, #10b981);
}

.metric-label {
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-text-secondary);
  margin-bottom: 0.5rem;
}

.metric-value {
  font-size: 1.25rem;
  font-weight: 700;
  color: #ffffff;
  line-height: 1.3;
}

/* ==========================================================================
   Module Cards & Tutorial Cards Grid
   ========================================================================== */
.module-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 1.75rem;
}

.card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 1.85rem;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.card:hover {
  transform: translateY(-4px);
  border-color: rgba(56, 189, 248, 0.4);
  box-shadow: var(--shadow-lg), 0 0 20px rgba(14, 165, 233, 0.15);
}

.card h3 {
  font-size: 1.3rem;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 0.75rem;
  letter-spacing: -0.01em;
}

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

/* ==========================================================================
   Editorial Content Sections & Rich Typography
   ========================================================================== */
.content-section {
  margin: 3.5rem 0;
}

.content-section h2 {
  font-size: 1.75rem;
  font-weight: 800;
  color: #ffffff;
  margin-bottom: 1.25rem;
  letter-spacing: -0.02em;
  position: relative;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--border-subtle);
}

.content-section h2::after {
  content: "";
  position: absolute;
  bottom: -1px;
  left: 0;
  width: 60px;
  height: 2px;
  background: var(--color-cyan-bright);
}

.content-section h3 {
  font-size: 1.3rem;
  font-weight: 700;
  color: #f1f5f9;
  margin: 1.75rem 0 0.85rem 0;
  letter-spacing: -0.01em;
}

.content-section p {
  color: var(--color-text-secondary);
  font-size: 1.05rem;
  line-height: 1.8;
  margin-bottom: 1.25rem;
}

.content-section ul, .content-section ol {
  color: var(--color-text-secondary);
  font-size: 1.02rem;
  line-height: 1.8;
}

.content-section li {
  margin-bottom: 0.6rem;
}

.content-section strong {
  color: #ffffff;
  font-weight: 600;
}

/* Terminal / Code Blocks */
.code-block {
  background-color: var(--bg-code);
  border: 1px solid var(--border-medium);
  border-radius: var(--radius-sm);
  padding: 1.25rem 1.5rem;
  margin: 1.5rem 0;
  overflow-x: auto;
  position: relative;
  box-shadow: inset 0 2px 6px rgba(0, 0, 0, 0.6);
}

.code-block code {
  font-family: var(--font-mono);
  font-size: 0.92rem;
  color: #38bdf8;
  line-height: 1.7;
  white-space: pre;
  display: block;
}

p code, li code {
  font-family: var(--font-mono);
  font-size: 0.88rem;
  background-color: rgba(255, 255, 255, 0.08);
  color: #38bdf8;
  padding: 0.2rem 0.45rem;
  border-radius: 4px;
  border: 1px solid var(--border-subtle);
}

/* Modern Data Tables */
.data-table-wrapper {
  overflow-x: auto;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  margin: 1.75rem 0;
  background-color: var(--bg-card);
  box-shadow: var(--shadow-sm);
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.92rem;
  text-align: left;
}

.data-table th, .data-table td {
  padding: 0.95rem 1.25rem;
  border-bottom: 1px solid var(--border-subtle);
}

.data-table th {
  background-color: rgba(0, 0, 0, 0.35);
  color: #ffffff;
  font-weight: 700;
  text-transform: uppercase;
  font-size: 0.8rem;
  letter-spacing: 0.06em;
}

.data-table tr:last-child td {
  border-bottom: none;
}

.data-table tbody tr:hover {
  background-color: rgba(255, 255, 255, 0.03);
}

/* ==========================================================================
   FAQ Accordions
   ========================================================================== */
.faq-accordion {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin: 1.5rem 0;
}

.faq-item {
  background-color: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 1.35rem 1.6rem;
  transition: all 0.2s ease;
}

.faq-item:hover {
  border-color: var(--border-medium);
}

.faq-question {
  font-size: 1.15rem;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 0.65rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.faq-answer p {
  color: var(--color-text-secondary);
  font-size: 0.98rem;
  line-height: 1.75;
  margin-bottom: 0;
}

/* ==========================================================================
   Global Site Footer
   ========================================================================== */
.site-footer {
  background-color: #05080f;
  border-top: 1px solid var(--border-subtle);
  padding: 4rem 1.5rem 2.5rem 1.5rem;
  color: var(--color-text-secondary);
  font-size: 0.92rem;
  margin-top: auto;
  position: relative;
}

.site-footer::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(14, 165, 233, 0.3), rgba(16, 185, 129, 0.3), transparent);
}

.footer-container, .footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr 1fr;
  gap: 2rem;
  margin-bottom: 3rem;
}

@media (max-width: 960px) {
  .footer-container, .footer-inner {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 540px) {
  .footer-container, .footer-inner {
    grid-template-columns: 1fr;
  }
}

.footer-column h4, .footer-col h3 {
  font-size: 0.9rem;
  font-weight: 700;
  text-transform: uppercase;
  color: #ffffff;
  letter-spacing: 0.06em;
  margin-bottom: 1.15rem;
}

.footer-links, .footer-nav-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

.footer-links a, .footer-nav-list a {
  color: var(--color-text-secondary);
  font-size: 0.9rem;
  transition: color 0.2s ease;
}

.footer-links a:hover, .footer-nav-list a:hover {
  color: var(--color-cyan-bright);
}

.footer-bottom {
  max-width: var(--max-width);
  margin: 0 auto;
  padding-top: 2rem;
  border-top: 1px solid var(--border-subtle);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

/* ==========================================================================
   Tutorial & GeoAI Specific Components
   ========================================================================== */
.terminal-window {
  background-color: var(--bg-code);
  border: 1px solid var(--border-medium);
  border-radius: var(--radius-md);
  margin: 1.75rem 0;
  overflow: hidden;
  box-shadow: var(--shadow-lg);
}

.terminal-header {
  background-color: #0b111e;
  padding: 0.65rem 1rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--border-subtle);
}

.terminal-dots {
  display: flex;
  gap: 6px;
}

.terminal-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}

.terminal-dot.red { background-color: #ef4444; }
.terminal-dot.yellow { background-color: #f59e0b; }
.terminal-dot.green { background-color: #10b981; }

.terminal-title {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--color-text-muted);
}

.terminal-body {
  padding: 1.25rem 1.5rem;
  overflow-x: auto;
}

.terminal-body code {
  font-family: var(--font-mono);
  font-size: 0.92rem;
  color: #38bdf8;
  line-height: 1.7;
  white-space: pre;
  display: block;
}

.step-card {
  border-left: 3px solid var(--color-cyan-bright);
  padding-left: 1.5rem;
  margin: 2rem 0;
  position: relative;
}

.step-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background-color: var(--color-cyan-bright);
  color: #070b14;
  font-weight: 800;
  font-size: 0.85rem;
  margin-bottom: 0.5rem;
}

/* Screen Reader Utility */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}