/* ============================================================
   ShaderStudy – Global Design System
   ============================================================ */

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

/* ── Custom Properties ─────────────────────────────────────── */
:root {
  /* Colors */
  --bg-base:        #08080f;
  --bg-surface:     #0f0f1a;
  --bg-elevated:    #161625;
  --bg-card:        #1a1a2e;
  --bg-hover:       #1f1f38;
  --bg-nav:         rgba(8, 8, 15, 0.7);

  --accent-1:       #7c3aed;
  --accent-2:       #a855f7;
  --accent-3:       #c026d3;
  --accent-glow:    rgba(124, 58, 237, 0.35);

  --text-primary:   #f0f0ff;
  --text-secondary: #a0a0c0;
  --text-muted:     #60607a;
  --text-accent:    #c084fc;

  --border-subtle:  rgba(255, 255, 255, 0.06);
  --border-muted:   rgba(255, 255, 255, 0.1);
  --border-accent:  rgba(124, 58, 237, 0.5);

  --radius-sm:   6px;
  --radius-md:   10px;
  --radius-lg:   16px;
  --radius-xl:   24px;
  --radius-full: 9999px;

  /* Spacing scale */
  --space-1:  4px;
  --space-2:  8px;
  --space-3:  12px;
  --space-4:  16px;
  --space-5:  20px;
  --space-6:  24px;
  --space-8:  32px;
  --space-10: 40px;
  --space-12: 48px;
  --space-16: 64px;
  --space-20: 80px;

  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

  --text-xs:   0.75rem;
  --text-sm:   0.875rem;
  --text-base: 1rem;
  --text-lg:   1.125rem;
  --text-xl:   1.25rem;
  --text-2xl:  1.5rem;
  --text-3xl:  1.875rem;
  --text-4xl:  2.25rem;
  --text-5xl:  3rem;
  --text-6xl:  3.75rem;

  /* Shadows */
  --shadow-sm:  0 1px 3px rgba(0,0,0,0.4);
  --shadow-md:  0 4px 16px rgba(0,0,0,0.5);
  --shadow-lg:  0 8px 32px rgba(0,0,0,0.6);
  --shadow-glow: 0 0 40px rgba(124, 58, 237, 0.25);

  /* Transitions */
  --transition-fast:   150ms ease;
  --transition-normal: 250ms ease;
  --transition-slow:   400ms ease;

  /* Gradients */
  --gradient-accent: linear-gradient(135deg, var(--accent-1), var(--accent-3));
  --gradient-accent-soft: linear-gradient(135deg, rgba(124,58,237,0.15), rgba(192,38,211,0.15));
  --gradient-surface: linear-gradient(180deg, var(--bg-surface), var(--bg-base));
}

:root[data-theme="light"] {
  --bg-base:        #f8fafc;
  --bg-surface:     #ffffff;
  --bg-elevated:    #f1f5f9;
  --bg-card:        #ffffff;
  --bg-hover:       #e2e8f0;
  --bg-nav:         rgba(255, 255, 255, 0.85);

  --accent-1:       #6d28d9;
  --accent-2:       #7c3aed;
  --accent-3:       #a21caf;
  --accent-glow:    rgba(109, 40, 217, 0.15);

  --text-primary:   #0f172a;
  --text-secondary: #475569;
  --text-muted:     #64748b;
  --text-accent:    #6d28d9;

  --border-subtle:  rgba(0, 0, 0, 0.08);
  --border-muted:   rgba(0, 0, 0, 0.12);
  --border-accent:  rgba(109, 40, 217, 0.3);

  --shadow-sm:  0 1px 2px rgba(0,0,0,0.05);
  --shadow-md:  0 4px 12px rgba(0,0,0,0.08);
  --shadow-lg:  0 8px 24px rgba(0,0,0,0.12);
  --shadow-glow: 0 0 20px rgba(124, 58, 237, 0.15);

  --gradient-accent-soft: linear-gradient(135deg, rgba(109,40,217,0.08), rgba(162,28,175,0.08));
}

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

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

body {
  font-family: var(--font-sans);
  font-size: var(--text-base);
  line-height: 1.6;
  color: var(--text-primary);
  background: var(--bg-base);
  min-height: 100vh;
  overflow-x: hidden;
}

a {
  color: var(--text-accent);
  text-decoration: none;
  transition: color var(--transition-fast);
}
a:hover { color: var(--accent-2); }

img, svg { display: block; }
button { cursor: pointer; border: none; background: none; font-family: inherit; }
ul, ol { list-style: none; }

/* ── Scrollbar ─────────────────────────────────────────────── */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: var(--bg-base); }
::-webkit-scrollbar-thumb {
  background: var(--bg-elevated);
  border-radius: var(--radius-full);
}
::-webkit-scrollbar-thumb:hover { background: var(--accent-1); }

/* ── Utility Classes ───────────────────────────────────────── */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.gradient-text {
  background: var(--gradient-accent);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  border-radius: var(--radius-full);
  font-size: var(--text-sm);
  font-weight: 600;
  transition: all var(--transition-normal);
  white-space: nowrap;
}

.btn-primary {
  background: var(--gradient-accent);
  color: #fff;
  box-shadow: 0 4px 20px var(--accent-glow);
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 32px var(--accent-glow);
  color: #fff;
}
.btn-primary:active { transform: translateY(0); }

.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
  border: 1px solid var(--border-muted);
}
.btn-ghost:hover {
  background: var(--bg-elevated);
  color: var(--text-primary);
  border-color: var(--border-accent);
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: 3px var(--space-3);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.badge-accent {
  background: rgba(124, 58, 237, 0.2);
  color: var(--accent-2);
  border: 1px solid rgba(124, 58, 237, 0.3);
}

.icon-btn {
  transition: all var(--transition-fast);
}
.icon-btn:hover {
  background: var(--bg-elevated);
  color: var(--text-primary) !important;
  border-color: var(--border-accent) !important;
}

/* ── Code blocks (highlight.js override) ──────────────────── */
.hljs-wrapper {
  position: relative;
  margin: var(--space-6) 0;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
  overflow: hidden;
}

.hljs-lang-label {
  position: absolute;
  top: var(--space-3);
  right: var(--space-4);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  pointer-events: none;
}

.hljs-copy-btn {
  position: absolute;
  top: var(--space-2);
  right: var(--space-2);
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-sm);
  font-size: var(--text-xs);
  font-weight: 500;
  color: var(--text-muted);
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  transition: all var(--transition-fast);
  opacity: 0;
}
.hljs-wrapper:hover .hljs-copy-btn { opacity: 1; }
.hljs-copy-btn:hover {
  color: var(--text-primary);
  border-color: var(--border-accent);
  background: var(--bg-hover);
}
.hljs-copy-btn.copied {
  color: #4ade80;
  border-color: rgba(74,222,128,0.4);
}

pre.hljs-pre {
  padding: var(--space-8) var(--space-6) var(--space-6);
  overflow-x: auto;
  background: #0d0d18 !important;
  border-radius: var(--radius-md);
}

code.hljs {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  line-height: 1.7;
  background: transparent !important;
}

/* ── Divider ───────────────────────────────────────────────── */
.divider {
  height: 1px;
  background: var(--border-subtle);
  border: none;
}

/* ── Animations ────────────────────────────────────────────── */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(20px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}

@keyframes pulse-glow {
  0%, 100% { box-shadow: 0 0 20px var(--accent-glow); }
  50%       { box-shadow: 0 0 40px rgba(124,58,237,0.5); }
}

@keyframes float {
  0%, 100% { transform: translateY(0px); }
  50%       { transform: translateY(-8px); }
}

@keyframes spin {
  from { transform: rotate(0deg); }
  to   { transform: rotate(360deg); }
}

.animate-fade-up  { animation: fadeUp  0.6s ease both; }
.animate-fade-in  { animation: fadeIn  0.4s ease both; }

.delay-100 { animation-delay: 0.1s; }
.delay-200 { animation-delay: 0.2s; }
.delay-300 { animation-delay: 0.3s; }
.delay-400 { animation-delay: 0.4s; }
.delay-500 { animation-delay: 0.5s; }