/* Design tokens – dark default, light optional */
:root,
[data-theme="dark"] {
  --bg-primary: #000000;
  --bg-secondary: #0c0c0e;
  --bg-elevated: #16161a;
  --bg-card: #1a1a1f;
  --bg-hover: #27272a;
  --border-subtle: #2a2a2e;
  --border-strong: #3f3f46;
  --text-primary: #f4f4f5;
  --text-secondary: #a1a1aa;
  --text-muted: #71717a;
  --accent: #8b5cf6;
  --accent-secondary: #a78bfa;
  --accent-gradient: linear-gradient(135deg, #7c3aed 0%, #8b5cf6 50%, #a78bfa 100%);
  --accent-glow: rgba(139, 92, 246, 0.35);
  --danger: #f87171;
  --success: #4ade80;
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.45);
  --shadow-md: 0 4px 24px rgba(0, 0, 0, 0.35);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --font-sans: "Inter", system-ui, -apple-system, sans-serif;
  --font-serif: "Georgia", "Times New Roman", serif;
  --touch-target: 44px;
  --page-gutter: 16px;
}

[data-theme="light"] {
  --bg-primary: #f8fafc;
  --bg-secondary: #f1f5f9;
  --bg-elevated: #ffffff;
  --bg-card: #ffffff;
  --bg-hover: #e2e8f0;
  --border-subtle: #e2e8f0;
  --border-strong: #cbd5e1;
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  --accent: #7c3aed;
  --accent-secondary: #8b5cf6;
  --accent-gradient: linear-gradient(135deg, #6d28d9 0%, #7c3aed 50%, #8b5cf6 100%);
  --accent-glow: rgba(124, 58, 237, 0.2);
  --danger: #dc2626;
  --success: #16a34a;
  --shadow-lg: 0 8px 32px rgba(15, 23, 42, 0.12);
  --shadow-md: 0 4px 24px rgba(15, 23, 42, 0.08);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  color-scheme: dark;
}

html[data-theme="light"] {
  color-scheme: light;
}

body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  background: linear-gradient(180deg, var(--bg-primary) 0%, var(--bg-secondary) 55%, var(--bg-primary) 100%);
  background-attachment: fixed;
  color: var(--text-primary);
  margin: 0;
  min-height: 100vh;
  overflow-x: hidden;
}

.theme-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: var(--touch-target);
  height: var(--touch-target);
  flex-shrink: 0;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-subtle);
  background: var(--bg-elevated);
  color: var(--text-secondary);
  cursor: pointer;
  transition: background 0.2s, color 0.2s, border-color 0.2s;
}

.theme-toggle:hover {
  background: var(--bg-hover);
  color: var(--accent-secondary);
  border-color: var(--accent-secondary);
}

.cta-button {
  display: block;
  width: 100%;
  min-height: var(--touch-target);
  padding: 12px 20px;
  font-size: 1rem;
  font-weight: 600;
  color: #fff;
  background: var(--accent-gradient);
  border-radius: var(--radius-md);
  text-decoration: none;
  text-align: center;
  box-sizing: border-box;
  box-shadow: 0 4px 20px var(--accent-glow);
  transition: transform 0.2s, box-shadow 0.2s, filter 0.2s;
}

@media (min-width: 600px) {
  .cta-button {
    display: inline-block;
    width: auto;
    padding: 14px 28px;
  }
}

.cta-button:hover {
  transform: translateY(-2px);
  filter: brightness(1.08);
  box-shadow: 0 8px 28px var(--accent-glow);
}

.cta-button--ghost {
  background: transparent;
  color: var(--text-primary);
  border: 1px solid var(--border-subtle);
  box-shadow: none;
}

.cta-button--ghost:hover {
  background: var(--bg-hover);
  filter: none;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
}

.site-footer {
  margin-top: auto;
  padding: 24px var(--page-gutter) 32px;
  text-align: center;
  border-top: 1px solid var(--border-subtle);
  color: var(--text-secondary);
  font-size: 0.85rem;
  line-height: 1.55;
}

@media (min-width: 768px) {
  .site-footer {
    padding: 32px 24px 40px;
    font-size: 0.9rem;
  }
}

.site-footer a {
  color: var(--accent-secondary);
  text-decoration: none;
}

.site-footer a:hover {
  text-decoration: underline;
}

/* Scroll-reveal animations */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.reveal-delay-1 { transition-delay: 0.1s; }
.reveal-delay-2 { transition-delay: 0.2s; }
.reveal-delay-3 { transition-delay: 0.3s; }

@keyframes heroFadeIn {
  from { opacity: 0; transform: translateY(16px); }
  to { opacity: 1; transform: translateY(0); }
}

.hero-animate {
  animation: heroFadeIn 0.8s ease forwards;
}

@media (prefers-reduced-motion: reduce) {
  .reveal,
  .hero-animate {
    opacity: 1;
    transform: none;
    animation: none;
    transition: none;
  }
}