/* ─────────────────────────────────────────────────────────────────────────
 * design-systems/claude/tokens.css
 *
 * Structured token bindings for "Design System Inspired by Claude (Anthropic)".
 * Literary salon aesthetic: warm parchment canvas, terracotta accent,
 * exclusive warm-toned neutrals, rounded humanist typography throughout.
 *
 * Key brand decisions encoded here:
 *   - Parchment (#f5f4ed) as page canvas — never pure white
 *   - Ivory (#faf9f5) for elevated card surfaces
 *   - Terracotta (#c96442) as the single brand accent — earthy, un-tech
 *   - All grays carry a yellow-brown undertone — no cool blue-grays
 *   - Rounded humanist sans for headings and UI — soft, clear, operational
 *   - Ring-based depth (0 0 0 1px) instead of traditional drop shadows
 *   - Generous body line-height (1.60) for a literary reading experience
 *   - Focus blue (#3898ec) is the only cool color — accessibility only
 * ─────────────────────────────────────────────────────────────────── */

:root {
  /* ─── Surface (3 levels) ─────────────────────────────────────────
   * Parchment (bg) → Ivory (surface) → Warm Sand (surface-warm).
   * Never use pure white as a page background — the warm cream IS
   * the Claude personality. */
  --bg: #f5f4ed;
  --surface: #faf9f5;
  --surface-warm: #e8e6dc;   /* Warm Sand — button bg, prominent interactive surfaces */

  /* ─── Foreground ramp (4 levels) ────────────────────────────────
   * Every gray carries a yellow-brown undertone. No cool blue-grays. */
  --fg: #141413;             /* Anthropic Near Black — warmest "black" in any major tech brand */
  --fg-2: #3d3d3a;           /* Dark Warm — dark text links, emphasized secondary text */
  --muted: #5e5d59;          /* Olive Gray — secondary body text */
  --meta: #87867f;           /* Stone Gray — tertiary text, footnotes, metadata */

  /* ─── Border (2 levels) ──────────────────────────────────────────
   * Cream-tinted borders — the gentlest possible containment. */
  --border: #f0eee6;         /* Border Cream — standard light-theme border */
  --border-soft: #e8e6dc;    /* Border Warm — section dividers, emphasized containment */

  /* ─── Accent ──────────────────────────────────────────────────────
   * Terracotta Brand — the only chromatic element on most screens.
   * Used for primary CTA buttons and highest-signal brand moments only. */
  --accent: #c96442;
  --accent-on: #faf9f5;      /* Ivory — fg when terracotta is the bg */
  --accent-hover: color-mix(in oklab, var(--accent), black 8%);
  --accent-active: color-mix(in oklab, var(--accent), black 14%);

  /* ─── Semantic ────────────────────────────────────────────────────
   * Error Crimson is a warm, deep red — serious without alarming.
   * Focus Blue (#3898ec) is the sole cool color in the system,
   * reserved for accessibility (input focus rings). */
  --success: #17a34a;
  --warn: #eab308;
  --danger: #b53333;         /* Error Crimson — warm red, not standard danger red */

  /* ─── Typography ──────────────────────────────────────────────────
   * Lato gives Latin text, digits, and controls a friendly rounded rhythm;
   * Noto Sans CJK SC keeps Chinese glyphs balanced with the Latin face.
   * Ubuntu Mono is reserved for codes and audit identifiers. */
  --font-display: "Lato", "Noto Sans CJK SC", "PingFang SC", sans-serif;
  --font-body: "Lato", "Noto Sans CJK SC", "PingFang SC", sans-serif;
  --font-mono: "Ubuntu Mono", "Noto Sans Mono CJK SC", ui-monospace, monospace;

  /* Type scale — DESIGN.md §3 Typography Rules.
   * 64px hero → 52px section → 36px sub → 32px card → 25px small */
  --text-xs: 10px;           /* Overline — uppercase labels at smallest scale */
  --text-sm: 14px;           /* Caption — metadata, descriptions */
  --text-base: 16px;         /* Body Standard */
  --text-lg: 20px;           /* Body Large — intro paragraphs */
  --text-xl: 25px;           /* Sub-heading Small */
  --text-2xl: 32px;          /* Sub-heading — card titles, feature names */
  --text-3xl: 52px;          /* Section Heading */
  --text-4xl: 64px;          /* Display / Hero — maximum impact, book-title presence */

  --leading-body: 1.55;      /* Comfortable reading rhythm for a dense operations UI */
  --leading-tight: 1.18;     /* Soft display rhythm without cramped counters */
  --tracking-display: -0.01em;

  /* ─── Spacing ─────────────────────────────────────────────────────
   * 8px base unit per DESIGN.md §5. Card internal padding ~24–32px. */
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 20px;
  --space-6: 24px;
  --space-8: 32px;
  --space-12: 48px;

  --section-y-desktop: 96px; /* Editorial pacing — generous like a magazine spread */
  --section-y-tablet: 64px;
  --section-y-phone: 48px;

  /* ─── Radius ──────────────────────────────────────────────────────
   * Claude's softness: comfortably rounded (8px) for standard,
   * generously rounded (12px) for primary, very rounded (16px) for
   * featured containers. No sharp corners — softness is core identity. */
  --radius-sm: 8px;          /* Comfortably rounded — standard buttons, cards */
  --radius-md: 12px;         /* Generously rounded — primary buttons, inputs, nav */
  --radius-lg: 16px;         /* Very rounded — featured containers, video players */
  --radius-pill: 9999px;     /* Chip-like elements (use sparingly) */

  /* ─── Elevation ───────────────────────────────────────────────────
   * Ring shadows (0px 0px 0px 1px) instead of drop shadows.
   * The signature is a border-like halo — shadow pretending to be
   * a border. Drop shadows only at 0.05 opacity when truly needed. */
  --elev-flat: none;
  --elev-ring: 0 0 0 1px var(--border);          /* Border-like halo */
  --elev-raised: rgba(0, 0, 0, 0.05) 0px 4px 24px; /* Whisper soft — barely visible lift */

  /* ─── Focus ring ──────────────────────────────────────────────────
   * Focus Blue (#3898ec) is the ONLY cool color in the Claude system.
   * Reserved exclusively for accessibility / keyboard focus. */
  --focus-ring: 0 0 0 3px rgba(56, 152, 236, 0.3);

  /* ─── Motion ──────────────────────────────────────────────────────
   * Short, purposeful transitions. The editorial warmth doesn't need
   * animation energy — interactions should feel calm. */
  --motion-fast: 150ms;
  --motion-base: 200ms;
  --ease-standard: cubic-bezier(0.2, 0, 0, 1);

  /* ─── Layout ──────────────────────────────────────────────────────
   * 1200px container, editorial layout. Hero is centered, feature
   * sections use 2–3 column card grids. */
  --container-max: 1200px;
  --container-gutter-desktop: 24px;
  --container-gutter-tablet: 16px;
  --container-gutter-phone: 12px;
}