/* ====== DESIGN TOKENS ====== */
:root {
  --font-display: 'Space Grotesk', system-ui, sans-serif;
  --font-body: 'Space Grotesk', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', 'Consolas', monospace;

  --text-xs:   clamp(0.75rem,  0.7rem  + 0.25vw, 0.875rem);
  --text-sm:   clamp(0.875rem, 0.8rem  + 0.35vw, 1rem);
  --text-base: clamp(1rem,     0.95rem + 0.25vw, 1.125rem);
  --text-lg:   clamp(1.125rem, 1rem    + 0.75vw, 1.5rem);
  --text-xl:   clamp(1.5rem,   1.2rem  + 1.25vw, 2.25rem);
  --text-2xl:  clamp(2rem,     1.2rem  + 2.5vw,  3.5rem);

  --space-1:  0.25rem;
  --space-2:  0.5rem;
  --space-3:  0.75rem;
  --space-4:  1rem;
  --space-5:  1.25rem;
  --space-6:  1.5rem;
  --space-8:  2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;

  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;

  --transition-interactive: 180ms cubic-bezier(0.16, 1, 0.3, 1);
}

/* ====== COLOR: Dark-first for technical / graphics theme ====== */
:root, [data-theme="dark"] {
  --color-bg:          #0e0f12;
  --color-surface:     #161820;
  --color-surface-2:   #1c1f2a;
  --color-border:      #2a2d3a;
  --color-text:        #d8dae3;
  --color-text-muted:  #7c7f8e;
  --color-text-faint:  #4a4d5a;
  --color-primary:     #5bb8c4;
  --color-primary-hover: #3d9aa7;
  --color-accent-warm: #e8915a;
  --color-accent-green:#6bc06b;
  --color-warning:     #d4944a;
  --color-error:       #cf5f6a;
  --color-blue:        #5a8fd4;

  --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.4);
  --shadow-lg: 0 12px 40px rgba(0,0,0,0.5);

  --canvas-bg: #1a1c24;
  --grid-line: rgba(255,255,255,0.06);
}

[data-theme="light"] {
  --color-bg:          #f4f3ef;
  --color-surface:     #ffffff;
  --color-surface-2:   #f9f8f5;
  --color-border:      #d4d1ca;
  --color-text:        #1c1a16;
  --color-text-muted:  #6b6960;
  --color-text-faint:  #a5a39c;
  --color-primary:     #1a8a96;
  --color-primary-hover: #0c6e78;
  --color-accent-warm: #c4712e;
  --color-accent-green:#3d8e3d;
  --color-warning:     #a06820;
  --color-error:       #a83842;
  --color-blue:        #3568a8;

  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.08);
  --shadow-lg: 0 12px 40px rgba(0,0,0,0.12);

  --canvas-bg: #ffffff;
  --grid-line: rgba(0,0,0,0.06);
}

@media (prefers-color-scheme: light) {
  :root:not([data-theme]) {
    --color-bg:          #f4f3ef;
    --color-surface:     #ffffff;
    --color-surface-2:   #f9f8f5;
    --color-border:      #d4d1ca;
    --color-text:        #1c1a16;
    --color-text-muted:  #6b6960;
    --color-text-faint:  #a5a39c;
    --color-primary:     #1a8a96;
    --color-primary-hover: #0c6e78;
    --color-accent-warm: #c4712e;
    --color-accent-green:#3d8e3d;
    --color-warning:     #a06820;
    --color-error:       #a83842;
    --color-blue:        #3568a8;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
    --shadow-md: 0 4px 16px rgba(0,0,0,0.08);
    --shadow-lg: 0 12px 40px rgba(0,0,0,0.12);
    --canvas-bg: #ffffff;
    --grid-line: rgba(0,0,0,0.06);
  }
}

/* ====== HEADER ====== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: color-mix(in srgb, var(--color-bg) 85%, transparent);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
}

.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: var(--space-3) var(--space-6);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
}

.logo-group {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.logo-icon {
  color: var(--color-primary);
  flex-shrink: 0;
}

.site-title {
  font-family: var(--font-display);
  font-size: var(--text-sm);
  font-weight: 600;
  letter-spacing: -0.01em;
  white-space: nowrap;
}

.header-nav {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  flex-wrap: wrap;
}

.nav-link {
  font-size: var(--text-xs);
  font-weight: 500;
  color: var(--color-text-muted);
  text-decoration: none;
  padding: var(--space-1) var(--space-2);
  border-radius: var(--radius-sm);
}

.nav-link:hover {
  color: var(--color-text);
  background: var(--color-surface);
}

.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  color: var(--color-text-muted);
  margin-left: var(--space-2);
}

.theme-toggle:hover {
  color: var(--color-text);
  background: var(--color-surface);
}

/* ====== HERO ====== */
.hero {
  padding: clamp(var(--space-12), 8vw, var(--space-24)) var(--space-6);
  text-align: center;
}

.hero-inner {
  max-width: 720px;
  margin: 0 auto;
}

.hero-tag {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-primary);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  margin-bottom: var(--space-4);
}

.hero-title {
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  font-weight: 700;
  letter-spacing: -0.025em;
  line-height: 1.1;
  margin-bottom: var(--space-6);
}

.hero-desc {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  max-width: 56ch;
  margin: 0 auto;
  line-height: 1.7;
}

/* ====== SECTIONS ====== */
.demo-section {
  padding: clamp(var(--space-10), 6vw, var(--space-20)) var(--space-6);
  border-top: 1px solid var(--color-border);
}

.section-header {
  max-width: 680px;
  margin: 0 auto var(--space-8);
}

.section-number {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-primary);
  font-weight: 600;
}

.section-title {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-top: var(--space-2);
  margin-bottom: var(--space-3);
}

.section-desc {
  color: var(--color-text-muted);
  font-size: var(--text-sm);
  line-height: 1.7;
}

/* ====== DEMO CARD ====== */
.demo-card {
  max-width: 900px;
  margin: 0 auto;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  box-shadow: var(--shadow-md);
}

.demo-controls {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4) var(--space-6);
  margin-bottom: var(--space-6);
  padding-bottom: var(--space-4);
  border-bottom: 1px solid var(--color-border);
}

.control-label {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-xs);
  font-weight: 500;
  color: var(--color-text-muted);
  white-space: nowrap;
}

.slider {
  width: 120px;
  accent-color: var(--color-primary);
  cursor: pointer;
}

.slider-val {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-primary);
  min-width: 50px;
  text-align: right;
}

.select-control {
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: var(--space-1) var(--space-3);
  font-size: var(--text-xs);
  color: var(--color-text);
  cursor: pointer;
}

/* ====== CANVAS LAYOUTS ====== */
.canvas-pair {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-4);
  margin-bottom: var(--space-4);
}

.canvas-single {
  margin-bottom: var(--space-4);
}

.canvas-single canvas {
  width: 100%;
  height: auto;
  border-radius: var(--radius-md);
  background: var(--canvas-bg);
}

.ssaa-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-3);
  margin-bottom: var(--space-4);
}

.inspector-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-4);
  margin-bottom: var(--space-4);
}

.canvas-wrap {
  position: relative;
}

.canvas-wrap canvas {
  width: 100%;
  height: auto;
  border-radius: var(--radius-md);
  background: var(--canvas-bg);
  image-rendering: pixelated;
  cursor: crosshair;
}

.canvas-label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 500;
  color: var(--color-text-muted);
  margin-bottom: var(--space-2);
  display: block;
}

.label-aliased { color: var(--color-error); }
.label-aa { color: var(--color-accent-green); }

.demo-note {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  line-height: 1.6;
  border-left: 2px solid var(--color-border);
  padding-left: var(--space-3);
  margin-top: var(--space-2);
}

/* ====== TEMPORAL INFO ====== */
.temporal-info {
  display: flex;
  gap: var(--space-3);
  flex-wrap: wrap;
  margin-bottom: var(--space-4);
}

.info-chip {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: var(--space-1) var(--space-3);
  color: var(--color-text-muted);
}

/* ====== PIXEL INFO ====== */
.pixel-info {
  display: flex;
  gap: var(--space-3);
  margin-top: var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
}

.pixel-info b {
  color: var(--color-text);
  font-weight: 600;
}

/* ====== FOOTER ====== */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding: var(--space-8) var(--space-6);
  text-align: center;
}

.site-footer p {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  max-width: 50ch;
  margin: 0 auto var(--space-3);
}

.site-footer a {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  text-decoration: none;
}

.site-footer a:hover {
  color: var(--color-primary);
}

/* ====== RESPONSIVE ====== */
@media (max-width: 768px) {
  .header-nav .nav-link { display: none; }

  .canvas-pair,
  .inspector-layout {
    grid-template-columns: 1fr;
  }

  .ssaa-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .demo-controls {
    flex-direction: column;
    gap: var(--space-3);
  }

  .slider {
    width: 100%;
    flex: 1;
  }
}

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