:root {
    /* Backgrounds (surface layers) */
    --surface-0: #0a0a0f;
    --surface-1: #12121a;
    --surface-2: #1a1a25;
    --surface-3: #242430;

    /* Foreground (text hierarchy) */
    --text-primary: #e8e8ed;
    --text-secondary: #a0a0b0;
    --text-muted: #8585a0;

    /* Accent (blue/cyan) */
    --accent: #38bdf8;
    --accent-hover: #7dd3fc;
    --accent-active: #0ea5e9;
    --accent-muted: rgba(56, 189, 248, 0.12);

    /* Semantic */
    --color-error: #f87171;
    --color-success: #4ade80;
    --color-warning: #fbbf24;

    /* Borders */
    --border-default: #1e1e2a;
    --border-subtle: #16161f;
    --border-accent: rgba(56, 189, 248, 0.3);

    /* Font stacks */
    --font-sans: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont,
        "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas,
        "Liberation Mono", monospace;

    /* Type scale */
    --text-xs: 0.75rem;
    --text-sm: 0.875rem;
    --text-base: 1rem;
    --text-lg: 1.25rem;
    --text-xl: 1.5rem;
    --text-2xl: 2rem;
    --text-3xl: 2.5rem;
    --text-4xl: 3rem;

    /* Spacing */
    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-6: 1.5rem;
    --space-8: 2rem;
    --space-12: 3rem;
    --space-16: 4rem;
    --space-24: 6rem;
    --space-32: 8rem;

    /* Named spacing aliases */
    --section-padding-y: var(--space-24);
    --section-padding-x: var(--space-6);
    --card-padding: var(--space-6);
    --card-gap: var(--space-4);
    --inline-gap: var(--space-2);
    --stack-gap: var(--space-4);

    /* Layout */
    --max-width-content: 72rem;
    --max-width-narrow: 48rem;
    --max-width-wide: 90rem;

    /* Motion */
    --transition-fast: 120ms ease-out;
    --transition-normal: 200ms ease-out;
    --transition-slow: 350ms ease-out;
}