/* ============================================================
   Performance Effective Solutions (PES) — Design System
   ============================================================ */

/* --- Google Fonts --- */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&display=swap');

/* --- CSS Custom Properties --- */
:root {
  /* Colors */
  --color-primary: #0a1628;
  --color-primary-light: #132744;
  --color-primary-lighter: #1a3360;
  --color-accent: #2563eb;
  --color-accent-hover: #1d4ed8;
  --color-accent-light: #3b82f6;
  --color-accent-bg: #eff6ff;
  --color-secondary: #059669;
  --color-secondary-light: #10b981;
  --color-secondary-bg: #ecfdf5;
  --color-gold: #d4a017;
  --color-gold-light: #f59e0b;

  /* Surfaces */
  --color-bg: #f8fafc;
  --color-bg-alt: #ffffff;
  --color-card: #ffffff;
  --color-card-hover: #f1f5f9;
  --color-border: #e2e8f0;
  --color-border-light: #f1f5f9;

  /* Text */
  --color-text: #0f172a;
  --color-text-secondary: #475569;
  --color-text-muted: #94a3b8;
  --color-text-inverse: #ffffff;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);

  /* Typography */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'SF Mono', 'Fira Code', 'Consolas', monospace;

  /* Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;
  --space-4xl: 6rem;

  /* Layout */
  --max-width: 1200px;
  --max-width-narrow: 900px;
  --nav-height: 72px;
  --border-radius: 8px;
  --border-radius-lg: 12px;
  --border-radius-xl: 16px;
  --border-radius-full: 9999px;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-normal: 250ms ease;
  --transition-slow: 350ms ease;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-family);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.7;
  min-height: 100vh;
}

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

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

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

ul {
  list-style: none;
}

/* --- Typography --- */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.25;
  color: var(--color-primary);
}

h1 { font-size: 3rem; letter-spacing: -0.02em; }
h2 { font-size: 2.25rem; letter-spacing: -0.01em; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }
h5 { font-size: 1.125rem; }
h6 { font-size: 1rem; }

p {
  color: var(--color-text-secondary);
  margin-bottom: var(--space-md);
}

.text-sm { font-size: 0.875rem; }
.text-lg { font-size: 1.125rem; }
.text-xl { font-size: 1.25rem; }
.text-muted { color: var(--color-text-muted); }
.text-secondary { color: var(--color-text-secondary); }
.text-accent { color: var(--color-accent); }
.text-green { color: var(--color-secondary); }
.text-gold { color: var(--color-gold); }

.font-mono { font-family: var(--font-mono); }
.font-medium { font-weight: 500; }
.font-semibold { font-weight: 600; }
.font-bold { font-weight: 700; }
.font-extrabold { font-weight: 800; }

.leading-tight { line-height: 1.25; }

/* --- Layout --- */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-xl);
}

.container-narrow {
  max-width: var(--max-width-narrow);
  margin: 0 auto;
  padding: 0 var(--space-xl);
}

.section {
  padding: var(--space-4xl) 0;
}

.section-dark {
  padding: var(--space-4xl) 0;
  background: var(--color-primary);
  color: var(--color-text-inverse);
}

.section-dark h2,
.section-dark h3,
.section-dark h4,
.section-dark p,
.section-dark .text-secondary,
.section-dark .text-muted {
  color: var(--color-text-inverse);
  opacity: 0.9;
}

.section-dark h2 { opacity: 1; }

.section-alt {
  padding: var(--space-4xl) 0;
  background: var(--color-bg-alt);
}

.section-accent {
  padding: var(--space-4xl) 0;
  background: var(--color-accent-bg);
}

.section-header {
  text-align: center;
  margin-bottom: var(--space-3xl);
}

.section-header h2 {
  margin-bottom: var(--space-md);
}

.section-header p {
  max-width: 700px;
  margin: 0 auto;
  font-size: 1.125rem;
}

.section-subtitle {
  display: inline-block;
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-accent);
  margin-bottom: var(--space-sm);
}

/* --- Grid --- */
.grid { display: grid; gap: var(--space-xl); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

/* --- Flex helpers --- */
.flex { display: flex; }
.flex-col { flex-direction: column; }
.flex-wrap { flex-wrap: wrap; }
.items-center { align-items: center; }
.items-start { align-items: flex-start; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.gap-sm { gap: var(--space-sm); }
.gap-md { gap: var(--space-md); }
.gap-lg { gap: var(--space-lg); }
.gap-xl { gap: var(--space-xl); }

/* --- Navigation --- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  z-index: 1000;
  display: flex;
  align-items: center;
}

.nav .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-weight: 800;
  font-size: 1.25rem;
  color: var(--color-primary);
  letter-spacing: -0.01em;
}

.nav-logo span {
  color: var(--color-accent);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
}

.nav-links a {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  transition: color var(--transition-fast);
  padding: var(--space-xs) 0;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--color-accent);
}

.nav-cta {
  padding: var(--space-sm) var(--space-lg);
  background: var(--color-accent);
  color: var(--color-text-inverse) !important;
  border-radius: var(--border-radius-full);
  font-weight: 600 !important;
  transition: background var(--transition-fast) !important;
}

.nav-cta:hover {
  background: var(--color-accent-hover) !important;
  color: var(--color-text-inverse) !important;
}

/* Dropdown */
.nav-dropdown {
  position: relative;
}

.nav-dropdown-toggle {
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: var(--space-xs);
}

.nav-dropdown-toggle::after {
  content: '\25BE';
  font-size: 0.625rem;
  transition: transform var(--transition-fast);
}

.nav-dropdown:hover .nav-dropdown-toggle::after {
  transform: rotate(180deg);
}

.nav-dropdown-menu {
  position: absolute;
  top: 100%;
  left: 0;
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius);
  box-shadow: var(--shadow-lg);
  min-width: 240px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: all var(--transition-normal);
  padding: var(--space-sm) 0;
}

.nav-dropdown:hover .nav-dropdown-menu {
  opacity: 1;
  visibility: visible;
  transform: translateY(4px);
}

.nav-dropdown-menu a {
  display: block;
  padding: var(--space-sm) var(--space-lg);
  font-size: 0.8125rem;
  color: var(--color-text-secondary);
}

.nav-dropdown-menu a:hover {
  background: var(--color-accent-bg);
  color: var(--color-accent);
}

/* Mobile nav */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  background: none;
  border: none;
  padding: var(--space-sm);
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-primary);
  transition: all var(--transition-normal);
}

.nav-mobile {
  display: none;
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: 0.75rem 1.75rem;
  font-size: 0.9375rem;
  font-weight: 600;
  font-family: var(--font-family);
  line-height: 1;
  border: none;
  border-radius: var(--border-radius-full);
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
}

.btn-primary {
  background: var(--color-accent);
  color: var(--color-text-inverse);
}

.btn-primary:hover {
  background: var(--color-accent-hover);
  color: var(--color-text-inverse);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn-secondary {
  background: var(--color-accent-bg);
  color: var(--color-accent);
}

.btn-secondary:hover {
  background: #dbeafe;
  color: var(--color-accent-hover);
}

.btn-outline {
  background: transparent;
  color: var(--color-accent);
  border: 2px solid var(--color-accent);
}

.btn-outline:hover {
  background: var(--color-accent);
  color: var(--color-text-inverse);
}

.btn-light {
  background: rgba(255, 255, 255, 0.15);
  color: var(--color-text-inverse);
  border: 1px solid rgba(255, 255, 255, 0.25);
}

.btn-light:hover {
  background: rgba(255, 255, 255, 0.25);
  color: var(--color-text-inverse);
  border-color: rgba(255, 255, 255, 0.4);
}

.btn-lg {
  padding: 1rem 2.25rem;
  font-size: 1.0625rem;
}

.btn-sm {
  padding: 0.5rem 1.25rem;
  font-size: 0.8125rem;
}

/* --- Hero --- */
.hero {
  padding: calc(var(--nav-height) + var(--space-4xl)) 0 var(--space-4xl);
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-lighter) 100%);
  color: var(--color-text-inverse);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(37, 99, 235, 0.15) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -30%;
  left: -10%;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(5, 150, 105, 0.1) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

.hero-video {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  z-index: 0;
  opacity: 0.3;
  pointer-events: none;
}

.hero-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(135deg, rgba(10, 22, 40, 0.85) 0%, rgba(10, 22, 40, 0.65) 100%);
  z-index: 0;
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 720px;
}

.hero h1 {
  font-size: 3.25rem;
  font-weight: 800;
  color: var(--color-text-inverse);
  margin-bottom: var(--space-lg);
  line-height: 1.15;
}

.hero h1 span {
  color: var(--color-accent-light);
}

.hero p {
  font-size: 1.2rem;
  color: rgba(255, 255, 255, 0.8);
  margin-bottom: var(--space-2xl);
  line-height: 1.8;
}

.hero-btns {
  display: flex;
  gap: var(--space-md);
  flex-wrap: wrap;
}

/* --- Cards --- */
.card {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius-lg);
  padding: var(--space-2xl);
  transition: all var(--transition-normal);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-accent-light);
}

.card-icon {
  width: 56px;
  height: 56px;
  background: var(--color-accent-bg);
  border-radius: var(--border-radius);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--space-lg);
  font-size: 1.5rem;
}

.card-icon svg {
  width: 28px;
  height: 28px;
  color: var(--color-accent);
}

.card-icon.green {
  background: var(--color-secondary-bg);
}

.card-icon.green svg {
  color: var(--color-secondary);
}

.card h3 {
  margin-bottom: var(--space-sm);
}

.card p {
  color: var(--color-text-secondary);
  font-size: 0.9375rem;
  margin-bottom: var(--space-lg);
}

.card-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  font-weight: 600;
  font-size: 0.875rem;
  color: var(--color-accent);
}

.card-link::after {
  content: '\2192';
  transition: transform var(--transition-fast);
}

.card-link:hover::after {
  transform: translateX(4px);
}

/* Service cards (home page) */
.service-card {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius-lg);
  overflow: hidden;
  transition: all var(--transition-normal);
}

.service-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-xl);
}

.service-card-image {
  height: 200px;
  background: linear-gradient(135deg, var(--color-primary-light), var(--color-primary-lighter));
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-xl);
}

.service-card-image svg {
  width: 80px;
  height: 80px;
  color: var(--color-accent-light);
}

.service-card-body {
  padding: var(--space-xl);
}

.service-card-body h3 {
  margin-bottom: var(--space-sm);
}

.service-card-body p {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  margin-bottom: var(--space-lg);
}

/* --- Stats --- */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-xl);
  text-align: center;
}

.stat-number {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--color-accent);
  line-height: 1;
  margin-bottom: var(--space-xs);
}

.stat-label {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  font-weight: 500;
}

.section-dark .stat-number {
  color: var(--color-accent-light);
}

.section-dark .stat-label {
  color: rgba(255, 255, 255, 0.7);
}

/* --- Timeline --- */
.timeline {
  position: relative;
  padding-left: var(--space-2xl);
}

.timeline::before {
  content: '';
  position: absolute;
  left: 0;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: var(--color-border);
}

.timeline-item {
  position: relative;
  padding-bottom: var(--space-2xl);
}

.timeline-item:last-child {
  padding-bottom: 0;
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: calc(-1 * var(--space-2xl) - 3px);
  top: 8px;
  width: 12px;
  height: 12px;
  background: var(--color-accent);
  border: 3px solid var(--color-accent-bg);
  border-radius: 50%;
}

.timeline-badge {
  display: inline-block;
  padding: 2px 10px;
  font-size: 0.75rem;
  font-weight: 600;
  background: var(--color-accent-bg);
  color: var(--color-accent);
  border-radius: var(--border-radius-full);
  margin-bottom: var(--space-sm);
}

.timeline-item h4 {
  margin-bottom: var(--space-xs);
}

.timeline-item p {
  font-size: 0.875rem;
  margin-bottom: 0;
}

/* --- Info Box --- */
.info-box {
  background: var(--color-accent-bg);
  border-left: 4px solid var(--color-accent);
  border-radius: 0 var(--border-radius) var(--border-radius) 0;
  padding: var(--space-lg) var(--space-xl);
  margin: var(--space-xl) 0;
}

.info-box.green {
  background: var(--color-secondary-bg);
  border-left-color: var(--color-secondary);
}

.info-box.dark {
  background: var(--color-primary-light);
  border-left-color: var(--color-accent-light);
  color: rgba(255, 255, 255, 0.9);
}

.info-box.dark h4 { color: var(--color-text-inverse); }
.info-box.dark p { color: rgba(255, 255, 255, 0.75); }

.info-box h4 {
  margin-bottom: var(--space-xs);
}

.info-box p {
  margin-bottom: 0;
  font-size: 0.9375rem;
}

/* --- Certifications / Badges --- */
.certs-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-lg);
}

.cert-card {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius);
  padding: var(--space-xl);
  display: flex;
  gap: var(--space-md);
  align-items: flex-start;
}

.cert-icon {
  width: 44px;
  height: 44px;
  background: var(--color-accent-bg);
  border-radius: var(--border-radius);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.cert-icon svg {
  width: 22px;
  height: 22px;
  color: var(--color-accent);
}

.cert-info h4 {
  font-size: 0.9375rem;
  margin-bottom: 2px;
}

.cert-info p {
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  margin-bottom: 0;
}

/* --- Page Header --- */
.page-header {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-lighter) 100%);
  padding: calc(var(--nav-height) + var(--space-3xl)) 0 var(--space-3xl);
  text-align: center;
  color: var(--color-text-inverse);
}

.page-header h1 {
  color: var(--color-text-inverse);
  margin-bottom: var(--space-sm);
}

.page-header p {
  color: rgba(255, 255, 255, 0.75);
  font-size: 1.125rem;
  max-width: 600px;
  margin: 0 auto;
}

/* --- Breadcrumb --- */
.breadcrumb {
  padding: var(--space-md) 0 0;
  font-size: 0.8125rem;
  color: var(--color-text-muted);
}

.breadcrumb a {
  color: var(--color-text-muted);
}

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

.breadcrumb span {
  margin: 0 var(--space-sm);
  color: var(--color-text-muted);
}

/* --- Service Page Content --- */
.service-content h2 {
  margin-top: var(--space-3xl);
  margin-bottom: var(--space-md);
}

.service-content h3 {
  margin-top: var(--space-2xl);
  margin-bottom: var(--space-md);
  color: var(--color-primary-light);
}

.service-content ul {
  list-style: disc;
  padding-left: var(--space-xl);
  margin-bottom: var(--space-lg);
}

.service-content ul li {
  color: var(--color-text-secondary);
  margin-bottom: var(--space-sm);
  font-size: 0.9375rem;
}

.service-content ul li strong {
  color: var(--color-text);
}

/* Nested lists */
.service-content ul ul {
  list-style: circle;
  margin-top: var(--space-sm);
  margin-bottom: 0;
}

.service-content ul ul li {
  font-size: 0.875rem;
}

/* --- Table --- */
.table-wrap {
  overflow-x: auto;
  margin: var(--space-xl) 0;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.875rem;
}

table th {
  background: var(--color-primary-light);
  color: var(--color-text-inverse);
  padding: var(--space-sm) var(--space-md);
  text-align: left;
  font-weight: 600;
  font-size: 0.8125rem;
  white-space: nowrap;
}

table th:first-child {
  border-radius: var(--border-radius) 0 0 0;
}

table th:last-child {
  border-radius: 0 var(--border-radius) 0 0;
}

table td {
  padding: var(--space-sm) var(--space-md);
  border-bottom: 1px solid var(--color-border);
  color: var(--color-text-secondary);
}

table tr:nth-child(even) td {
  background: var(--color-bg);
}

/* --- Diagram Container ---
 *   Enlarged 2026-05-31: increased padding from var(--space-xl) to
 *   var(--space-2xl), added max-width: 100% and width: 100% so the
 *   Mermaid SVG renders at full container width. Use overflow-x: auto
 *   to allow horizontal scroll on narrow viewports.
 */
.diagram-container {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius-lg);
  padding: var(--space-2xl);
  margin: var(--space-2xl) 0;
  overflow-x: auto;
  max-width: 100%;
  width: 100%;
}

.diagram-container h4 {
  margin-bottom: var(--space-lg);
  text-align: center;
}

/* --- Code Block --- */
.code-block {
  background: #0d1117;
  border-radius: var(--border-radius);
  padding: var(--space-lg);
  margin: var(--space-lg) 0;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  line-height: 1.6;
  color: #e6edf3;
}

.code-block .comment { color: #8b949e; }
.code-block .keyword { color: #ff7b72; }
.code-block .string { color: #a5d6ff; }
.code-block .function { color: #d2a8ff; }
.code-block .variable { color: #79c0ff; }

/* --- Form --- */
.form-group {
  margin-bottom: var(--space-xl);
}

.form-label {
  display: block;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: var(--space-sm);
}

.form-input,
.form-select,
.form-textarea {
  width: 100%;
  padding: 0.75rem 1rem;
  font-size: 0.9375rem;
  font-family: var(--font-family);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius);
  background: var(--color-card);
  color: var(--color-text);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-input::placeholder,
.form-textarea::placeholder {
  color: var(--color-text-muted);
}

.form-textarea {
  min-height: 120px;
  resize: vertical;
}

.form-hint {
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  margin-top: var(--space-xs);
}

/* Checkbox group */
.checkbox-group {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: var(--space-sm);
}

.checkbox-item {
  display: flex;
  align-items: flex-start;
  gap: var(--space-sm);
  padding: var(--space-sm);
  border-radius: var(--border-radius);
  transition: background var(--transition-fast);
}

.checkbox-item:hover {
  background: var(--color-border-light);
}

.checkbox-item input[type="checkbox"] {
  margin-top: 3px;
  width: 18px;
  height: 18px;
  accent-color: var(--color-accent);
  flex-shrink: 0;
  cursor: pointer;
}

.checkbox-item label {
  font-size: 0.875rem;
  cursor: pointer;
  color: var(--color-text-secondary);
}

.required::after {
  content: ' *';
  color: #ef4444;
}

/* --- Footer --- */
.footer {
  background: var(--color-primary);
  padding: var(--space-3xl) 0 var(--space-xl);
  color: rgba(255, 255, 255, 0.7);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: var(--space-3xl);
  margin-bottom: var(--space-3xl);
}

.footer h4 {
  color: var(--color-text-inverse);
  font-size: 0.9375rem;
  margin-bottom: var(--space-md);
}

.footer p {
  font-size: 0.875rem;
  color: rgba(255, 255, 255, 0.6);
}

.footer a {
  font-size: 0.875rem;
  color: rgba(255, 255, 255, 0.6);
}

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

.footer-links {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: var(--space-xl);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8125rem;
}

.footer-bottom p {
  margin-bottom: 0;
}

/* References */
.references {
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius);
  padding: var(--space-lg);
  margin-top: var(--space-xl);
}

.references h4 {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  margin-bottom: var(--space-sm);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.references ul {
  list-style: none;
  padding: 0;
}

.references li {
  font-size: 0.8125rem;
  margin-bottom: 4px;
}

.references li a {
  color: var(--color-text-secondary);
  word-break: break-all;
}

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

/* --- Utility --- */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mt-sm { margin-top: var(--space-sm); }
.mt-md { margin-top: var(--space-md); }
.mt-lg { margin-top: var(--space-lg); }
.mt-xl { margin-top: var(--space-xl); }
.mt-2xl { margin-top: var(--space-2xl); }
.mt-3xl { margin-top: var(--space-3xl); }

.mb-sm { margin-bottom: var(--space-sm); }
.mb-md { margin-bottom: var(--space-md); }
.mb-lg { margin-bottom: var(--space-lg); }
.mb-xl { margin-bottom: var(--space-xl); }
.mb-2xl { margin-bottom: var(--space-2xl); }
.mb-3xl { margin-bottom: var(--space-3xl); }

.p-sm { padding: var(--space-sm); }
.p-md { padding: var(--space-md); }
.p-lg { padding: var(--space-lg); }
.p-xl { padding: var(--space-xl); }
.p-2xl { padding: var(--space-2xl); }

/* --- Page badges --- */
.badge {
  display: inline-block;
  padding: 3px 10px;
  font-size: 0.75rem;
  font-weight: 600;
  border-radius: var(--border-radius-full);
}

.badge-blue {
  background: var(--color-accent-bg);
  color: var(--color-accent);
}

.badge-green {
  background: var(--color-secondary-bg);
  color: var(--color-secondary);
}

.badge-gold {
  background: #fef3c7;
  color: #b45309;
}

/* --- Image cards --- */
.image-card {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius-lg);
  overflow: hidden;
  text-align: center;
}

.image-card-figure {
  background: linear-gradient(135deg, var(--color-primary-light), var(--color-primary-lighter));
  padding: var(--space-2xl);
  min-height: 180px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.image-card-figure svg {
  width: 100px;
  height: 100px;
  color: var(--color-accent-light);
}

.image-card-figure img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  padding: var(--space-md);
  display: block;
}

.image-card-body {
  padding: var(--space-md);
}

.image-card-body p {
  font-size: 0.8125rem;
  margin-bottom: 0;
}

/* --- Fade-in animation --- */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  animation: fadeInUp 0.6s ease forwards;
}

@keyframes fadeInUp {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.delay-1 { animation-delay: 0.1s; }
.delay-2 { animation-delay: 0.2s; }
.delay-3 { animation-delay: 0.3s; }
.delay-4 { animation-delay: 0.4s; }

/* --- Scroll to top --- */
.scroll-top {
  position: fixed;
  bottom: var(--space-xl);
  right: var(--space-xl);
  width: 44px;
  height: 44px;
  background: var(--color-accent);
  color: var(--color-text-inverse);
  border: none;
  border-radius: 50%;
  font-size: 1.25rem;
  cursor: pointer;
  opacity: 0;
  transform: translateY(10px);
  transition: all var(--transition-normal);
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
}

.scroll-top.visible {
  opacity: 1;
  transform: translateY(0);
}

.scroll-top:hover {
  background: var(--color-accent-hover);
  transform: translateY(-3px);
}

/* --- Sitemap --- */
.sitemap {
  columns: 3;
  column-gap: var(--space-2xl);
}

.sitemap-group {
  break-inside: avoid;
  margin-bottom: var(--space-2xl);
}

.sitemap-group h4 {
  font-size: 0.875rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-accent);
  margin-bottom: var(--space-sm);
}

.sitemap-group a {
  display: block;
  font-size: 0.875rem;
  padding: 4px 0;
  color: var(--color-text-secondary);
}

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

/* --- Values --- */
.value-card {
  text-align: center;
  padding: var(--space-2xl);
}

.value-icon {
  width: 72px;
  height: 72px;
  margin: 0 auto var(--space-lg);
  background: var(--color-accent-bg);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
}

.value-icon svg {
  width: 36px;
  height: 36px;
  color: var(--color-accent);
}

/* --- Contact --- */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-3xl);
}

.contact-info-item {
  display: flex;
  gap: var(--space-md);
  margin-bottom: var(--space-xl);
}

.contact-info-icon {
  width: 44px;
  height: 44px;
  background: var(--color-accent-bg);
  border-radius: var(--border-radius);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.contact-info-icon svg {
  width: 20px;
  height: 20px;
  color: var(--color-accent);
}

.alert {
  padding: var(--space-lg);
  border-radius: var(--border-radius);
  margin-bottom: var(--space-lg);
  font-size: 0.9375rem;
}

.alert-success {
  background: var(--color-secondary-bg);
  color: var(--color-secondary);
  border: 1px solid var(--color-secondary-light);
}

.alert-error {
  background: #fef2f2;
  color: #dc2626;
  border: 1px solid #fca5a5;
}

.hidden {
  display: none !important;
}

/* --- Mermaid fix --- */
/*   Added svg width/height rule 2026-05-31 to scale diagrams to
 *   fill the .diagram-container at full width.
 */
.mermaid {
  display: flex;
  justify-content: center;
}

.mermaid svg {
  max-width: 100%;
  height: auto;
}

/* --- Responsive --- */
@media (max-width: 1024px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
  .sitemap { columns: 2; }

  h1 { font-size: 2.5rem; }
  h2 { font-size: 1.875rem; }
  .hero h1 { font-size: 2.5rem; }
}

@media (max-width: 768px) {
  :root {
    --space-4xl: 3rem;
    --space-3xl: 2rem;
  }

  .nav-links { display: none; }
  .nav-toggle { display: flex; }

  .nav-mobile {
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--color-card);
    padding: var(--space-xl);
    z-index: 999;
    flex-direction: column;
    gap: var(--space-md);
    overflow-y: auto;
  }

  .nav-mobile.active { display: flex; }

  .nav-mobile a {
    display: block;
    padding: var(--space-sm) 0;
    font-size: 1rem;
    font-weight: 500;
    color: var(--color-text);
    border-bottom: 1px solid var(--color-border-light);
  }

  .nav-mobile .nav-dropdown-menu {
    position: static;
    opacity: 1;
    visibility: visible;
    transform: none;
    box-shadow: none;
    border: none;
    padding-left: var(--space-md);
  }

  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .sitemap { columns: 1; }
  .footer-bottom { flex-direction: column; gap: var(--space-sm); text-align: center; }
  .hero-btns { flex-direction: column; align-items: flex-start; }

  h1 { font-size: 2rem; }
  h2 { font-size: 1.625rem; }
  .hero h1 { font-size: 2rem; }
  .hero p { font-size: 1rem; }
}

@media (max-width: 480px) {
  .checkbox-group { grid-template-columns: 1fr; }
  .certs-grid { grid-template-columns: 1fr; }
}

/* --- Diagram Zoom Button --- */
.diagram-zoom-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-xs) var(--space-md);
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--color-primary);
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius);
  cursor: pointer;
  transition: background 0.2s;
  margin-bottom: var(--space-sm);
}
.diagram-zoom-btn:hover { background: var(--color-primary-light); color: var(--color-text-inverse); }
.diagram-container[data-zoomed="true"] {
  transform: scale(1.5);
  transform-origin: top left;
  z-index: 100;
  margin-bottom: calc(var(--space-4xl) * 2);
  position: relative;
}
.diagram-container[data-zoomed="true"] + .diagram-zoom-btn {
  margin-top: var(--space-2xl);
}