/* Design tokens — 2026 redesign
   Source: 新DESIGN2.md (§1 视觉定位 / §色彩 / §字体)
   System: warm ivory page × deep charcoal text, ONE restrained accent colour.
   Colour budget from the design document: 70–80% light, 15–20% dark, 5–10% accent.
   To switch the whole site's accent, edit only the three --c-accent* values. */

:root{
  /* --- accent presets: keep exactly ONE uncommented --- */
  --c-accent:#8a6440;         /* 低饱和铜棕 */
  --c-accent-strong:#6d4c2d;  /* hover / small text on light */
  --c-accent-wash:#f2e8db;    /* tinted background */
  /* 深酒红  --c-accent:#6d2b33; --c-accent-strong:#571f26; --c-accent-wash:#f3e4e4; */
  /* 深墨绿  --c-accent:#22463a; --c-accent-strong:#183329; --c-accent-wash:#e5ece8; */

  /* --- neutrals: warm, never pure white / pure black --- */
  --c-bg:#f7f4ee;
  --c-bg-sunk:#efe9df;
  --c-surface:#fffdf9;
  --c-ink:#1c1a17;
  --c-ink-soft:#4a453d;
  --c-ink-mute:#7b7468;
  --c-line:#e3dccd;
  --c-line-strong:#cdc4b2;
  --c-on-accent:#fffdf9;
  /* text on the dark (15–20%) surfaces */
  --c-on-ink:#fffdf9;
  --c-on-ink-soft:rgba(255,253,249,.78);
  --c-on-ink-mute:rgba(255,253,249,.6);
  --c-on-ink-line:rgba(255,253,249,.28);

  /* --- typography --- */
  --font-display:Georgia,"Times New Roman","Songti SC",serif;
  --font-body:system-ui,-apple-system,"Segoe UI",Roboto,Helvetica,Arial,"PingFang SC","Microsoft YaHei",sans-serif;
  --fs-display:clamp(2.4rem,5.4vw,4.6rem);
  --fs-h2:clamp(1.7rem,3vw,2.6rem);
  --fs-h3:clamp(1.25rem,1.8vw,1.6rem);
  --fs-h4:1.0625rem;
  --fs-lead:clamp(1.05rem,1.5vw,1.3rem);
  --fs-body:1rem;
  --fs-small:.875rem;
  --fs-eyebrow:.75rem;
  --lh-tight:1.12;
  --lh-body:1.65;
  --ls-tight:-.015em;
  --ls-eyebrow:.14em;
  --measure:66ch;

  /* --- space scale --- */
  --space-1:.25rem;
  --space-2:.5rem;
  --space-3:.75rem;
  --space-4:1rem;
  --space-5:1.5rem;
  --space-6:2rem;
  --space-7:3rem;
  --space-8:4rem;
  --section-y:clamp(3.5rem,7vw,7rem);
  --section-y-tight:clamp(2.5rem,4vw,4rem);

  /* --- layout --- */
  --wrap:1240px;
  --wrap-narrow:840px;
  --gutter:clamp(1.25rem,4vw,2.5rem);

  /* --- edges & motion --- */
  --r-sm:4px;
  --r-md:10px;
  --r-pill:999px;
  --border-hair:1px solid var(--c-line);
  --dur:.18s;
  --ease:cubic-bezier(.4,0,.2,1);

  /* --- compatibility aliases for stylesheets not yet replaced --- */
  --color-ink:var(--c-ink);
  --color-background:var(--c-bg);
  --color-focus:var(--c-accent);
  --radius-control:var(--r-sm);
  --space-section:var(--section-y);
}