/* ==========================================================================
   南京兰台 官网 · 设计令牌与基础排版（2026-10 改版）
   静态站点，无框架、无构建步骤。所有页面共用这一层令牌。
   色彩：靛蓝（品牌主色）+ 深海军蓝（深色区块）+ 橙色（仅作点缀标记）
   ========================================================================== */
:root {
  --brand: #2a1fd0;
  --brand-600: #2216b4;
  --brand-700: #1a108f;
  --brand-50: #f1f0ff;
  --brand-100: #e4e2ff;
  --brand-200: #c9c4f2;
  --violet: #6d5efc;
  --sky: #0ea5e9;
  --warm: #ff8c0e;
  --warm-50: #fff4e8;
  --ok: #16a34a;

  --navy-950: #070a22;
  --navy-900: #0b1033;
  --navy-800: #121a4d;
  --navy-700: #1d2665;

  --ink-900: #0f1229;
  --ink-800: #1d2140;
  --ink-700: #33385a;
  --ink-600: #4c5272;
  --ink-500: #676d8a;
  --ink-400: #8a90aa;
  --ink-300: #b4b9cf;
  --line: #e3e6f1;
  --line-soft: #eef0f7;
  --surface-0: #ffffff;
  --surface-1: #f7f8fc;
  --surface-2: #eef1f8;

  --r-sm: 8px;
  --r-md: 14px;
  --r-lg: 20px;
  --r-xl: 28px;
  --r-pill: 999px;

  --shell: 1240px;
  --gutter: clamp(20px, 4vw, 40px);
  --nav-h: 72px;
  --sp-section: clamp(72px, 9vw, 128px);

  --font-sans: "Archivo", -apple-system, BlinkMacSystemFont, "PingFang SC", "HarmonyOS Sans SC",
    "Microsoft YaHei UI", "Microsoft YaHei", "Noto Sans CJK SC", "Source Han Sans SC", "Hiragino Sans GB", sans-serif;
  --font-num: "Archivo", "DIN Alternate", "Segoe UI", -apple-system, sans-serif;

  --fs-display: clamp(2.1rem, 1.3rem + 3.2vw, 3.6rem);
  --fs-h1: clamp(1.9rem, 1.3rem + 2.4vw, 3rem);
  --fs-h2: clamp(1.6rem, 1.15rem + 1.6vw, 2.4rem);
  --fs-h3: clamp(1.08rem, 1rem + .3vw, 1.25rem);
  --fs-lead: clamp(1.02rem, .97rem + .25vw, 1.16rem);

  --shadow-1: 0 1px 2px rgba(15, 18, 60, .06), 0 1px 1px rgba(15, 18, 60, .04);
  --shadow-2: 0 14px 34px -16px rgba(15, 18, 60, .22), 0 3px 8px rgba(15, 18, 60, .05);
  --shadow-3: 0 40px 80px -30px rgba(10, 12, 50, .45), 0 10px 24px -8px rgba(10, 12, 50, .18);
  --ring: 0 0 0 3px rgba(42, 31, 208, .3);
  --ease: cubic-bezier(.2, .7, .2, 1);
}

@font-face {
  font-family: "Archivo";
  src: url("../fonts/archivo-latin-var.woff2") format("woff2");
  font-weight: 100 900;
  font-display: swap;
  unicode-range: U+0000-00FF, U+2013-2014, U+2018-201D, U+2026;
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; scroll-behavior: smooth; scroll-padding-top: calc(var(--nav-h) + 16px); }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } *, *::before, *::after { animation: none !important; transition: none !important; } }
body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.8;
  color: var(--ink-700);
  background: var(--surface-0);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  font-feature-settings: "palt" 0;
}
img, svg { display: block; max-width: 100%; height: auto; }
a { color: var(--brand); text-decoration: none; }
a:hover { color: var(--brand-700); }
h1, h2, h3, h4 { color: var(--ink-900); margin: 0; line-height: 1.3; font-weight: 700; letter-spacing: .01em; text-wrap: balance; }
p { margin: 0; text-wrap: pretty; }
ul, ol { margin: 0; padding: 0; }
figure { margin: 0; }
button, input, select, textarea { font: inherit; color: inherit; }
:focus-visible { outline: none; box-shadow: var(--ring); border-radius: 6px; }
.skip-link { position: absolute; left: 12px; top: -60px; z-index: 100; background: var(--brand); color: #fff; padding: 8px 14px; border-radius: var(--r-sm); }
.skip-link:focus { top: 12px; color: #fff; }
.visually-hidden { position: absolute !important; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.shell { width: 100%; max-width: var(--shell); margin-inline: auto; padding-inline: var(--gutter); }
.num { font-family: var(--font-num); font-variant-numeric: tabular-nums; }