/* Design tokens — the only place raw brand hex values are defined. */
:root {
  /* Color — surface ramp built on #0a0a0f */
  --color-surface: #0a0a0f;
  --color-surface-raised: #12121a;
  --color-surface-overlay: #1a1a24;
  --color-surface-muted: #22222e;

  /* Color — accent ramp */
  --color-accent: #6366f1;
  --color-accent-strong: #8b5cf6;
  --color-accent-soft: #a855f7;
  --color-accent-cool: #3b82f6;

  /* Color — text ramp. muted and subtle stay at least 4.5:1 on --color-surface. */
  --color-text: #f4f4f8;
  --color-text-muted: #d2d2dc;
  --color-text-subtle: #b8b8c8;

  /* Color — glass and elevation */
  --surface-glass: linear-gradient(
    135deg,
    rgba(255, 255, 255, 0.1) 0%,
    rgba(255, 255, 255, 0.05) 100%
  );
  --surface-glass-border: rgba(255, 255, 255, 0.15);
  --surface-glass-border-strong: rgba(255, 255, 255, 0.25);
  --shadow-soft: 0 4px 24px rgba(0, 0, 0, 0.4), inset 0 1px 0 rgba(255, 255, 255, 0.1);
  --shadow-raised: 0 8px 32px rgba(99, 102, 241, 0.2), inset 0 1px 0 rgba(255, 255, 255, 0.15);
  --blur-glass: 16px;

  /* Typography */
  --font-sans: system-ui, sans-serif;
  --font-mono:
    ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, 'Liberation Mono', 'Courier New',
    monospace;
  --text-xs: clamp(0.75rem, 0.7rem + 0.2vw, 0.8125rem);
  --text-sm: clamp(0.875rem, 0.8rem + 0.25vw, 0.9375rem);
  --text-md: clamp(1rem, 0.95rem + 0.3vw, 1.125rem);
  --text-lg: clamp(1.125rem, 1rem + 0.5vw, 1.375rem);
  --text-xl: clamp(1.375rem, 1.1rem + 0.9vw, 1.75rem);
  --text-2xl: clamp(1.75rem, 1.3rem + 1.4vw, 2.25rem);
  --text-3xl: clamp(2.25rem, 1.6rem + 2vw, 3rem);
  --leading-tight: 1.2;
  --leading-normal: 1.5;
  --leading-relaxed: 1.7;
  --tracking-wide: 0.08em;

  /* Spacing */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-7: 2rem;
  --space-8: 2.5rem;
  --space-9: 3rem;
  --space-10: 4rem;
  --space-11: 5rem;
  --space-12: 6rem;

  /* Radii and layout */
  --radius-sm: 0.375rem;
  --radius-md: 0.75rem;
  --radius-lg: 1rem;
  --radius-pill: 999px;
  --content-max: 72rem;
  --content-gutter: clamp(1rem, 4vw, 2rem);

  /* Motion */
  --duration-fast: 150ms;
  --duration-base: 250ms;
  --duration-slow: 400ms;
  --ease-standard: cubic-bezier(0.4, 0, 0.2, 1);
  --ease-emphasized: cubic-bezier(0.2, 0, 0, 1);

  /* Focus */
  --focus-ring-color: var(--color-accent);
  --focus-ring-width: 2px;
  --focus-ring-offset: 3px;
}

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

html {
  color-scheme: dark;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--color-surface);
  color: var(--color-text);
  font-family: var(--font-sans);
  font-size: var(--text-md);
  line-height: var(--leading-normal);
  -webkit-font-smoothing: antialiased;
  color-scheme: dark;
}

:focus-visible {
  outline: var(--focus-ring-width) solid var(--focus-ring-color);
  outline-offset: var(--focus-ring-offset);
}

.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;
}

.skip-link {
  position: absolute;
  top: var(--space-2);
  left: var(--space-2);
  z-index: 1000;
  padding: var(--space-2) var(--space-4);
  background: var(--color-surface-raised);
  color: var(--color-text);
  border-radius: var(--radius-sm);
  text-decoration: none;
  transform: translateY(-200%);
  transition: transform var(--duration-fast) var(--ease-standard);
}

.skip-link:focus {
  transform: translateY(0);
}

.glass-surface {
  background: var(--surface-glass);
  backdrop-filter: blur(var(--blur-glass));
  -webkit-backdrop-filter: blur(var(--blur-glass));
  border: 1px solid var(--surface-glass-border);
  box-shadow: var(--shadow-soft);
}

.content-container {
  width: min(100% - 2 * var(--content-gutter), var(--content-max));
  margin-inline: auto;
}

.stack {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

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

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}