/* design tokens · Transformer学习站
   视觉关键词：注意力、并行、缩放、涌现
   主色=注意力靛紫（attention indigo），辅色=梯度青（gradient cyan）
   明暗两套独立取色（非反色），对比度满足正文 ≥ 4.5:1 */

:root {
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;

  --radius: 14px;
  --radius-sm: 9px;
  --shadow: 0 1px 2px rgba(30, 25, 70, 0.06), 0 10px 30px rgba(30, 25, 70, 0.07);
  --shadow-soft: 0 1px 2px rgba(30, 25, 70, 0.05);
  --speed: 180ms ease;

  --grid-line: rgba(99, 102, 241, 0.06);
}

html[data-theme="light"] {
  color-scheme: light;
  --bg: #f6f7fc;
  --bg-hero: linear-gradient(160deg, #eaebfc 0%, #f6f7fc 55%, #e3f6fa 100%);
  --surface: #ffffff;
  --surface-2: #edeff8;
  --text: #1a1e32;
  --muted: #5b607d;
  --border: #dee0ee;
  --primary: #6366f1;
  --primary-strong: #4f46e5;
  --primary-soft: #e5e6fc;
  --accent: #0891b2;
  --accent-soft: #dcf3f9;
  --danger: #b3372f;
  --ok: #1a7f4b;

  --lv-entry: #0891b2;   /* 入门 · 青 */
  --lv-core: #6366f1;    /* 核心 · 靛 */
  --lv-advanced: #8b5cf6;/* 进阶 · 紫 */
  --lv-frontier: #ec4899;/* 前沿 · 品红 */
}

html[data-theme="dark"] {
  color-scheme: dark;
  --bg: #0d0f1a;
  --bg-hero: linear-gradient(160deg, #1c1e4a 0%, #0d0f1a 55%, #0a2a33 100%);
  --surface: #161830;
  --surface-2: #1f2240;
  --text: #e4e6f5;
  --muted: #9ba0c4;
  --border: #2c3050;
  --primary: #818cf8;
  --primary-strong: #a5b0fb;
  --primary-soft: #262a5e;
  --accent: #22d3ee;
  --accent-soft: #0e3644;
  --danger: #ff8f88;
  --ok: #5fd89b;

  --lv-entry: #22d3ee;
  --lv-core: #818cf8;
  --lv-advanced: #a78bfa;
  --lv-frontier: #f472b6;

  --shadow: 0 1px 2px rgba(0, 0, 0, 0.4), 0 10px 30px rgba(0, 0, 0, 0.35);
  --shadow-soft: 0 1px 2px rgba(0, 0, 0, 0.35);
  --grid-line: rgba(129, 140, 248, 0.07);
}

@media (prefers-reduced-motion: reduce) {
  :root { --speed: 0ms; }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}