/* Shared visual language for every subpage: same background, same gutters, same footer gap.
   页面级别只保留各自的内容排版，底色 / 光斑 / 左右留白 / 页脚间距统一在 site.css 的变量里。 */
.site-subpage { color: #172b4a; background: var(--page-bg); }
/* 顶部光斑：全站子页默认同一套，页面 CSS 不再各自重写。 */
.site-subpage::before {
  content: ""; position: absolute; top: 0; left: 0; right: 0; height: 960px; z-index: -1; pointer-events: none;
  background:
    radial-gradient(ellipse 62% 42% at 20% 0%, rgba(214, 232, 255, .8) 0, transparent 68%),
    radial-gradient(ellipse 55% 38% at 80% 0%, rgba(230, 221, 255, .65) 0, transparent 66%),
    radial-gradient(ellipse 70% 44% at 50% 22%, rgba(224, 246, 255, .55) 0, transparent 70%);
}
.site-subpage main { width: min(1200px, calc(100% - var(--site-gutter) * 2)); margin: 0 auto; }
.site-subpage :is(h1,h2,h3) { color: #172b4a; }
.site-subpage :is(h1,h2,h3,p,span,li,a,button,summary,dt,dd) { font-family: -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Microsoft YaHei', sans-serif; }
.site-subpage summary:focus-visible, .table-wrap:focus-visible { outline: 3px solid #355fac; outline-offset: 4px; }
.visually-hidden { position: absolute; width: 1px; height: 1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; }