:root {
  color-scheme: light dark;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;

  /* Color Tokens */
  --bg-dark: #0a0e17;
  --bg-light: #f8fafc;
  --card-dark: #111827;
  --card-light: #ffffff;
  --border-dark: #1f293d;
  --border-light: #e2e8f0;

  --text-dark: #f1f5f9;
  --text-light: #0f172a;
  --text-muted-dark: #94a3b8;
  --text-muted-light: #64748b;

  --accent-cyan: #06b6d4;
  --accent-indigo: #6366f1;
  --accent-amber: #f59e0b;
  --accent-emerald: #10b981;

  --bg: light-dark(var(--bg-light), var(--bg-dark));
  --card-bg: light-dark(var(--card-light), var(--card-dark));
  --border: light-dark(var(--border-light), var(--border-dark));
  --text: light-dark(var(--text-light), var(--text-dark));
  --text-muted: light-dark(var(--text-muted-light), var(--text-muted-dark));
  
  --scrollbar-track: light-dark(#f1f5f9, #0f172a);
  --scrollbar-thumb: light-dark(#cbd5e1, #334155);
  scrollbar-color: var(--scrollbar-thumb) var(--scrollbar-track);
}

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

body {
  font-family: var(--font-sans);
  background-color: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
}

/* Header & Nav */
header {
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(12px);
  position: sticky;
  top: 0;
  z-index: 50;
  background-color: light-dark(rgba(248, 250, 252, 0.85), rgba(10, 14, 23, 0.85));
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text);
  text-decoration: none;
}

.brand-badge {
  font-size: 0.75rem;
  padding: 0.2rem 0.5rem;
  background: linear-gradient(135deg, var(--accent-indigo), var(--accent-cyan));
  color: #fff;
  border-radius: 9999px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

nav ul {
  display: flex;
  list-style: none;
  gap: 1.5rem;
}

nav a {
  color: var(--text-muted);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.95rem;
  transition: color 0.15s ease;
}

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

.cta-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  background: linear-gradient(135deg, var(--accent-indigo), var(--accent-cyan));
  color: #ffffff;
  padding: 0.65rem 1.25rem;
  border-radius: 8px;
  font-weight: 600;
  text-decoration: none;
  border: none;
  cursor: pointer;
  font-size: 0.95rem;
  transition: transform 0.15s ease, opacity 0.15s ease;
}

.cta-button:hover {
  transform: translateY(-1px);
  opacity: 0.95;
}

.cta-secondary {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
}

.cta-secondary:hover {
  background: var(--border);
}

/* Hero Section */
.hero {
  max-width: 1100px;
  margin: 4rem auto 3rem;
  padding: 0 1.5rem;
  text-align: center;
}

.hero-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 0.85rem;
  background: light-dark(#e0f2fe, rgba(6, 182, 212, 0.12));
  color: var(--accent-cyan);
  border: 1px solid light-dark(#bae6fd, rgba(6, 182, 212, 0.3));
  border-radius: 9999px;
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 1.5rem;
}

.hero h1 {
  font-size: clamp(2.25rem, 5vw, 3.75rem);
  font-weight: 800;
  line-height: 1.15;
  margin-bottom: 1.25rem;
  letter-spacing: -0.02em;
}

.gradient-text {
  background: linear-gradient(135deg, var(--accent-cyan), var(--accent-indigo));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero p {
  font-size: 1.2rem;
  color: var(--text-muted);
  max-width: 720px;
  margin: 0 auto 2rem;
}

.hero-actions {
  display: flex;
  justify-content: center;
  gap: 1rem;
  flex-wrap: wrap;
}

/* Feature Grid */
.features {
  max-width: 1200px;
  margin: 4rem auto;
  padding: 0 1.5rem;
}

.section-title {
  text-align: center;
  margin-bottom: 2.5rem;
}

.section-title h2 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 1.75rem;
}

.card {
  background-color: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 2rem;
  transition: border-color 0.2s ease, transform 0.2s ease;
}

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

.card-icon {
  font-size: 2rem;
  margin-bottom: 1rem;
  display: inline-block;
}

.card h3 {
  font-size: 1.25rem;
  margin-bottom: 0.75rem;
  font-weight: 600;
}

.card p {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.55;
}

/* Interactive Sandbox */
.interactive-section {
  max-width: 900px;
  margin: 4rem auto;
  padding: 2.5rem;
  background-color: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 16px;
}

.form-group {
  margin-bottom: 1.5rem;
}

label {
  display: block;
  font-weight: 600;
  margin-bottom: 0.5rem;
  font-size: 0.95rem;
}

input[type="text"], textarea, select {
  width: 100%;
  padding: 0.75rem 1rem;
  border-radius: 8px;
  border: 1px solid var(--border);
  background-color: var(--bg);
  color: var(--text);
  font-family: inherit;
  font-size: 1rem;
  transition: border-color 0.15s ease;
}

input:focus, textarea:focus, select:focus {
  outline: none;
  border-color: var(--accent-cyan);
}

.output-panel {
  margin-top: 1.5rem;
  background-color: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1.25rem;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  white-space: pre-wrap;
  display: none;
}

/* Footer */
footer {
  border-top: 1px solid var(--border);
  padding: 2.5rem 1.5rem;
  margin-top: 5rem;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.9rem;
}