/* 主题 ① 极简科技蓝白 */
body.theme-blue {
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", Inter, sans-serif;
  --maxw: 1140px;
  --gutter: 18px;
  --header-h: 64px;
  --radius: 14px;
  --radius-sm: 10px;
  --grid-gap: 18px;

  --bg: #f4f8fc;
  --surface: #ffffff;
  --text: #0c1a2e;
  --muted: #5a6d82;
  --heading: #0c1a2e;
  --border: #d8e4ef;
  --link: #0b6bcb;
  --link-hover: #0958ad;

  --accent: #0b6bcb;
  --accent-ink: #ffffff;

  --header-bg: rgba(255, 255, 255, 0.92);
  --header-blur: blur(12px);
  --nav-hover-bg: rgba(11, 107, 203, 0.08);
  --nav-active-bg: rgba(11, 107, 203, 0.12);
  --shadow-md: 0 12px 40px rgba(12, 26, 46, 0.08);

  --hero-title: #0c1a2e;
  --hero-lead: #4a5f75;
  --hero-strong: #0c1a2e;

  --tag-border: #c5d9eb;
  --tag-bg: #ffffff;
  --tag-text: #2c4a63;
  --code-bg: #e8f2fa;

  --callout-border: #b3d4f5;
  --callout-bg: #e8f4ff;
  --callout-text: #1a3a52;
  --callout-strong: #0b6bcb;
  --callout-code-bg: rgba(255, 255, 255, 0.85);
  --callout-code-text: #0b3d91;

  --card-border: #d8e4ef;
  --card-bg: #ffffff;
  --card-shadow: 0 4px 20px rgba(12, 26, 46, 0.06);

  --codeblock-border: #1a3a52;
  --codeblock-bg: #0f2744;
  --codeblock-text: #e8f1f8;

  --footer-bg: #ffffff;
  --footer-text: #5a6d82;
  --footer-heading: #0c1a2e;
  --footer-link: #5a6d82;

  --alert-error-bg: #fef2f2;
  --alert-error-text: #991b1b;
  --alert-error-border: #fecaca;
  --alert-ok-bg: #ecfdf5;
  --alert-ok-text: #065f46;
  --alert-ok-border: #a7f3d0;
}

body.theme-blue .hero.hero-surface {
  background: linear-gradient(180deg, #ffffff 0%, #f4f8fc 100%);
  border-bottom: 1px solid var(--border);
}

body.theme-blue .section-alt {
  background: #eef4fa;
}