/* ─────────────────────────────────────────────────────────────────────
 * Theme · swiss-ikb
 *   Swiss International Style. The signature is two-fold:
 *     1) ALL display + hero text uses extra-light (200 weight) Inter /
 *        Helvetica. Tight tracking, big sizes — "越大越细" (bigger gets
 *        thinner). This is the opposite of bauhaus-bold's 900 weight.
 *     2) A 1px hairline grid (#e0e0e0) is baked into the stage as the
 *        designer's invisible-but-visible scaffolding.
 *   The single saturated accent is IKB (International Klein Blue) —
 *   crisp, deep, encyclopedic. Used for kicker / kpi / link emphasis.
 *
 *   Swap accent for the other 3 guizang Swiss flavors by changing
 *   --accent only:
 *     • lemon yellow  #FFD500 — set --accent-on to #0a0a0a (yellow can't
 *       carry white text)
 *     • lemon green   #C5E803 — same, --accent-on = #0a0a0a
 *     • safety orange #FF6B35 — keep --accent-on white but use weight ≥ 600
 *
 *   character knobs:
 *     • hero numbers   — Inter, weight 200 (SIGNATURE — extra-light)
 *     • rule           — 1px solid hairline grey
 *     • card           — flat 0 radius (Swiss = direct rectangles)
 *     • surface        — 1px hairline grid (very faint)
 *     • motion         — punchy + linear (Swiss isn't springy)
 * ───────────────────────────────────────────────────────────────────── */
:root {
  /* ─── palette ─── */
  --shell:        #e8e8e6;
  --surface:      #fafaf8;
  --surface-2:    #f0f0ee;
  --surface-3:    #d4d4d2;
  --text:         #0a0a0a;
  --text-2:       #2a2a2a;
  --text-mute:    #737373;
  --text-faint:   #a8a8a8;
  --rule:         #e0e0e0;
  --accent:       #002fa7;             /* IKB — International Klein Blue */
  --accent-soft:  rgba(0, 47, 167, 0.08);
  --accent-glow:  rgba(0, 47, 167, 0.35);

  /* ─── fonts (sans everywhere — Swiss is anti-serif) ─── */
  --font-display-cn: "Noto Sans SC", "Source Han Sans SC", -apple-system, sans-serif;
  --font-display-en: "Inter", "Helvetica Neue", "Helvetica", "Arial", sans-serif;
  --font-body:       "Inter", "Helvetica Neue", "Noto Sans SC", -apple-system, sans-serif;
  --font-mono:       "JetBrains Mono", "SF Mono", ui-monospace, monospace;
  --font-features:   "tnum", "ss01", "ss02", "cv02";

  /* ─── motion: punchy + linear (Swiss isn't springy) ─── */
  --dur-quick:     180ms;
  --dur-base:      400ms;
  --dur-slow:      650ms;
  --dur-cinematic: 1000ms;

  /* ─── design identity: international style ─── */
  --r-card:        var(--r-flat);     /* SIGNATURE — direct rectangles */
  --r-stage:       0;
  --rule-w:        1px;
  --rule-style:    solid;
  --hero-num-font:    var(--font-display-en);
  --hero-num-style:   normal;
  --hero-num-weight:  200;             /* SIGNATURE — extra-light */
  --hero-num-track:   -0.04em;
  --stage-pad-x:   96px;
  --stage-pad-y:   72px;
  --card-shadow:   inset 0 0 0 1px var(--rule);
  --shadow-stage:
    0 60px 160px rgba(0, 0, 0, 0.18),
    0 0 0 1px rgba(0, 0, 0, 0.06);

  /* ─── decoration: SIGNATURE — 1px hairline grid (the Swiss scaffold) ─── */
  --surface-pattern:
    linear-gradient(rgba(10, 10, 10, 0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(10, 10, 10, 0.045) 1px, transparent 1px);
  --surface-pattern-size: 64px 64px;
  --surface-pattern-blend: normal;
  --surface-pattern-opacity: 0.85;
}