:root {
  --mono: 'SF Mono', 'Monaco', 'Cascadia Code', 'Roboto Mono', 'Courier New', monospace;
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 2rem;
  --space-lg: 4rem;
  --space-xl: 6rem;
  --bg: #ffffff;
  --bg-2: #f8f9fa;
  --bg-3: #e9ecef;
  --text: #000;
  --text-dim: #000;
  --border: #dee2e6;
  --accent: rgba(45, 90, 39, 0.2);
}

/* Dark theme (default) */
[data-theme*="dark"] {
  --bg: #000;
  --bg-2: #1a1a1a;
  --bg-3: #2a2a2a;
  --text: #fff;
  --text-dim: #fff;
  --border: #333;
  --accent: rgba(0, 255, 65, 0.2);
}

/* Theme-based image switching */
.hero-image-picture.dark-theme {
  display: none;
}

[data-theme*="dark"] .hero-image-picture.light-theme {
  display: none;
}

[data-theme*="dark"] .hero-image-picture.dark-theme {
  display: block;
}

[data-theme="dark-green"] {
  --text: #00ff41;
}

[data-theme="dark-blue"] {
  --text: #0041ff;
}

[data-theme="light-green"] {
  --text: #03b930;
}

[data-theme="light-blue"] {
  --text: #0433bf;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: "Google Sans Code", monospace;
  font-optical-sizing: auto;
  font-weight: 500;
  font-style: normal;
  font-display: swap;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
  scroll-behavior: smooth;
  font-size: 15px;
  transition: background-color 0.3s ease, color 0.3s ease;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-md);
}

.card {
  border: 1px solid var(--border);
  background: var(--bg-3);
  padding: var(--space-md);
  transition: all 0.2s ease;
}

.card:hover {
  border-color: var(--text);
}

.icon {
  width: 48px;
  height: 48px;
  background: var(--bg-2);
  color: var(--text);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  border: 1px solid var(--border);
  margin: 0 auto var(--space-sm);
}

.btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-xs);
  padding: var(--space-sm) var(--space-md);
  background: var(--text);
  color: var(--bg);
  text-decoration: none;
  font-weight: 500;
  border: 1px solid var(--text);
  transition: all 0.2s ease;
}

.btn:hover {
  background: transparent;
  color: var(--text);
}

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

.btn.inverse:hover {
  background: var(--text);
  color: var(--bg);
  border-color: var(--text);
}

.grid {
  display: grid;
  gap: var(--space-md);
}

.grid-3 {
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.grid-stats {
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
}

.text-center {
  text-align: center;
}

.text-dim {
  color: var(--text-dim);
}

.flex-between {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

/* Theme Switcher */
.theme-switcher {
  position: fixed;
  bottom: 20px;
  right: 20px;
  z-index: 1000;
}

.theme-toggle {
  display: block;
  background: var(--bg);
  border: 2px solid var(--text);
  width: 30px;
  height: 30px;
  overflow: hidden;
  color: transparent;
}

/* Skip link */
.skip-link {
  position: absolute;
  top: -40px;
  left: 6px;
  background: var(--text);
  color: var(--bg);
  padding: var(--space-xs);
  text-decoration: none;
  z-index: 100;
}

.skip-link:focus {
  top: 6px;
}

/* Header */
header {
  padding: var(--space-md) 0;
  border-bottom: 1px solid var(--border);
  background: var(--bg-2);
}

nav ul {
  list-style: none;
  display: flex;
  justify-content: center;
  gap: var(--space-md);
}

nav a {
  display: flex;
  justify-content: center;
  min-width: 100px;
  background: var(--bg);
  color: var(--text);
  text-decoration: none;
  padding: var(--space-xs) var(--space-sm);
  border: 1px solid var(--border);
  transition: all 0.2s ease;
}

nav a:hover,
nav a:focus {
  border-color: var(--text);
}

.logo {
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: bold;
  font-size: 18px;
  margin-bottom: var(--space-md);
  text-decoration: none;
  letter-spacing: 0.1em;
}

.logo:hover {
  border-color: var(--text);
}

/* Hero */
.hero {
  padding: var(--space-xl) 0;
  text-align: center;
  background: linear-gradient(135deg, var(--bg) 0%, var(--bg-3) 100%);
}

.hero h1 {
  font-size: clamp(48px, 8vw, 112px);
  font-weight: 300;
  margin-bottom: var(--space-md);
}

.hero p {
  font-size: 18px;
  max-width: 600px;
  margin: 0 auto var(--space-lg);
  color: var(--text-dim);
}

.hero-features {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-lg);
  margin-bottom: var(--space-lg);
  flex-wrap: wrap;
}

.hero-links {
  display: flex;
  justify-content: center;
  gap: var(--space-md);
  margin-bottom: var(--space-lg);
}

.hero-image img {
  max-width: 100%;
  height: auto;
  margin: 0 auto;
}

/* Sections */
section {
  padding: var(--space-xl) 0;
}

.section-alt {
  background: var(--bg-2);
}

h2 {
  font-size: clamp(32px, 4vw, 56px);
  font-weight: 300;
  text-align: center;
  margin-bottom: var(--space-md);
}

h3 {
  font-size: 20px;
  font-weight: 500;
  margin-bottom: var(--space-sm);
}

/* Stats */
.stat {
  text-align: center;
  min-width: 120px;
}

.stat-number {
  font-size: 40px;
  font-weight: 300;
  margin-bottom: var(--space-xs);
}

.stat-label {
  font-size: 12px;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 1px;
}

/* Download links */
.download-link {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-sm);
  text-decoration: none;
  color: var(--text);
  border: 1px solid transparent;
  margin-bottom: var(--space-xs);
  transition: all 0.2s ease;
}

.download-link:hover {
  border-color: var(--text);
  background: var(--bg);
}

.download-size {
  font-size: 13px;
  color: var(--text-dim);
}

/* FAQ */
.faq {
  max-width: 800px;
  margin: 0 auto;
}

details {
  border: 1px solid var(--border);
  margin-bottom: var(--space-sm);
  background: var(--bg-3);
  transition: background 0.2s ease;
}

summary {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-md);
  cursor: pointer;
  font-weight: 500;
  font-size: 16px;
  list-style: none;
  color: var(--text);
  transition: background 0.2s ease;
}

details:hover,
summary:hover {
  background: var(--bg);
}

summary::-webkit-details-marker {
  display: none;
}

summary::after {
  content: '[+]';
}

details[open] summary::after {
  content: '[-]';
}

.faq-content {
  padding: 0 var(--space-md) var(--space-md);
  color: var(--text-dim);
  font-size: 14px;
}

/* Footer */
footer {
  background: var(--bg);
  padding: var(--space-lg) 0;
  text-align: center;
  border-top: 1px solid var(--border);
}

.footer-logo {
  width: 48px;
  height: 48px;
  margin: 0 auto var(--space-md);
  font-weight: bold;
  text-decoration: none;
  letter-spacing: 0.1em;
}

.footer-logo:hover {
  border-color: var(--text);
}

.footer-nav {
  display: flex;
  justify-content: center;
  gap: var(--space-md);
  margin-bottom: var(--space-md);
  flex-wrap: wrap;
}

.footer-text {
  color: var(--text-dim);
  font-size: 13px;
  margin-top: var(--space-md);
  padding-top: var(--space-md);
  border-top: 1px solid var(--border);
}

/* Code */
.code-block {
  background: var(--bg);
  padding: var(--space-sm);
  border: 1px solid var(--border);
  margin: var(--space-xs) 0;
  font-size: 13px;
  overflow-x: auto;
}

/* Responsive */
@media (max-width: 768px) {
  .container {
    padding: 0 var(--space-sm);
  }

  .hero-features,
  nav ul,
  .footer-nav {
    gap: var(--space-sm);
  }

  .hero h1 {
    font-size: clamp(32px, 8vw, 56px);
  }

  .hero-links {
    flex-direction: column;
  }

  h2 {
    font-size: clamp(20px, 4vw, 32px);
  }

  section {
    padding: var(--space-lg) 0;
  }

  .icon {
    width: 40px;
    height: 40px;
    font-size: 16px;
  }

  .theme-switcher {
    top: 10px;
    right: 10px;
  }
}

/* Focus */
*:focus-visible {
  outline: 1px solid var(--text);
  outline-offset: 2px;
}

/* Scrollbar */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--bg);
}

::-webkit-scrollbar-thumb {
  background: var(--border);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text);
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
  clip-path: inset(50%);
}