/**
 * Documentoved Design System
 * Layer: Design Tokens (CSS Custom Properties)
 *
 * This is the single source of truth for visual language.
 * All other layers (base, components, app) should consume these --ds-* tokens.
 *
 * Philosophy:
 * - Light corporate minimalism for a professional knowledge workspace.
 * - Solid surfaces, restrained borders, high readability.
 * - Consistent scale for spacing, type, radius, motion.
 *
 * Future:
 * - Can be mapped to Tailwind theme config if we introduce a build step later.
 */

:root {
  /* =========================================================
     Color Palette — Core
     ========================================================= */
  --ds-color-black: #0f172a;
  --ds-color-bg-app: #f8f9fc;
  --ds-color-bg-subtle: #f0f3f8;
  --ds-color-bg-elevated: #ffffff;
  --ds-color-bg-panel: #f9fbfd;

  /* Text */
  --ds-color-text-primary: #0f172a;
  --ds-color-text-secondary: #334155;
  --ds-color-text-muted: #64748b;
  --ds-color-text-on-accent: #ffffff;

  /* Accent — corporate blue */
  --ds-color-accent: #2563eb;
  --ds-color-accent-dark: #1d4ed8;
  --ds-color-accent-soft: #e8f0ff;
  --ds-color-accent-border: #b7cbff;

  /* Semantic / status */
  --ds-color-success: #10b981;
  --ds-color-warning: #f59e0b;
  --ds-color-error: #ef4444;
  --ds-color-info: #3b82f6;

  /* Lines & dividers */
  --ds-color-line: #d9e2ec;
  --ds-color-line-strong: #c4d0dd;

  /* =========================================================
     Typography
     ========================================================= */
  --ds-font-sans: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --ds-font-mono: ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;

  --ds-font-size-xs: 11px;
  --ds-font-size-sm: 12px;
  --ds-font-size-md: 14px;
  --ds-font-size-lg: 16px;
  --ds-font-size-xl: 20px;
  --ds-font-size-2xl: 28px;
  --ds-font-size-3xl: 36px;

  --ds-line-height-tight: 1.2;
  --ds-line-height-normal: 1.5;
  --ds-line-height-relaxed: 1.65;

  --ds-font-weight-normal: 400;
  --ds-font-weight-medium: 500;
  --ds-font-weight-semibold: 600;
  --ds-font-weight-bold: 700;

  --ds-letter-spacing-tight: 0;
  --ds-letter-spacing-normal: 0;
  --ds-letter-spacing-wide: 0.04em;

  /* =========================================================
     Spacing Scale (4px base)
     ========================================================= */
  --ds-space-0: 0;
  --ds-space-1: 4px;
  --ds-space-2: 8px;
  --ds-space-3: 12px;
  --ds-space-4: 16px;
  --ds-space-5: 20px;
  --ds-space-6: 24px;
  --ds-space-8: 32px;
  --ds-space-10: 40px;
  --ds-space-12: 48px;
  --ds-space-16: 64px;

  /* =========================================================
     Radius
     ========================================================= */
  --ds-radius-xs: 6px;
  --ds-radius-sm: 10px;
  --ds-radius-md: 16px;
  --ds-radius-lg: 22px;
  --ds-radius-xl: 28px;
  --ds-radius-2xl: 32px;
  --ds-radius-full: 9999px;
  --ds-radius-composer: 26px;
  --ds-radius-bubble: 20px;
  --ds-radius-pill: 9999px;

  /* =========================================================
     Effects
     ========================================================= */
  --ds-shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.06);
  --ds-shadow-md: 0 4px 20px -8px rgba(15, 23, 42, 0.1);
  --ds-shadow-composer: 0 2px 16px -4px rgba(15, 23, 42, 0.08);
  --ds-shadow-lg: 0 18px 42px -28px rgba(15, 23, 42, 0.28);
  --ds-focus-ring: 0 0 0 3px rgba(37, 99, 235, 0.14);

  /* =========================================================
     Motion & Transitions
     ========================================================= */
  --ds-transition-fast: 120ms cubic-bezier(0.4, 0, 0.2, 1);
  --ds-transition-base: 180ms cubic-bezier(0.4, 0, 0.2, 1);
  --ds-transition-slow: 280ms cubic-bezier(0.4, 0, 0.2, 1);

  --ds-ease-standard: cubic-bezier(0.4, 0.0, 0.2, 1);
  --ds-ease-emphasized: cubic-bezier(0.2, 0.0, 0.0, 1.0);

  /* Reduced motion will override many of these in base.css */
}

/* Semantic aliases (easy to consume in components) */
:root {
  --ds-color-surface: var(--ds-color-bg-elevated);
  --ds-color-surface-strong: var(--ds-color-bg-panel);

  --ds-color-border: var(--ds-color-line);
  --ds-color-border-strong: var(--ds-color-line-strong);

  --ds-color-primary: var(--ds-color-accent);
  --ds-color-primary-dark: var(--ds-color-accent-dark);
  --ds-color-primary-soft: var(--ds-color-accent-soft);

  --ds-surface-chat: rgba(255, 255, 255, 0.55);
}