/* Copyright (c) 2026 zenitudeserenity
   All rights reserved.
   最小重置 + 可访问性底线（06 §五）：焦点环永不去掉、跳到正文、减少动效。 */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; }
body {
  margin: 0; background: var(--bg); color: var(--text);
  font: var(--fs-md)/1.6 var(--font-sans);
  -webkit-font-smoothing: antialiased;
}
h1, h2, h3, h4, p, ul, ol, figure, dl, dd { margin: 0; }
h1, h2, h3, h4 { line-height: 1.3; font-weight: 650; }
ul[class], ol[class] { padding: 0; list-style: none; }
img, svg, video { display: block; max-width: 100%; }
button, input, select, textarea { font: inherit; color: inherit; }
a { color: var(--primary); text-underline-offset: 2px; }
code, kbd, samp, .mono { font-family: var(--font-mono); font-size: .92em; }
table { border-collapse: collapse; }
[hidden] { display: none !important; }
/* 🔴 焦点环：2px 实线 + 2px 外移，所有可聚焦元素，键盘操作时永远看得见 */
:focus-visible { outline: 2px solid var(--focus); outline-offset: 2px; }
:focus:not(:focus-visible) { outline: none; }
/* 输入框例外：自动聚焦时 :focus-visible 不一定命中，而光标在哪个框里必须一眼看得到 */
input:not([type=checkbox]):not([type=radio]):focus, textarea:focus, select:focus { outline: 2px solid var(--focus); outline-offset: 2px; }
.skip {
  position: absolute; left: var(--sp-3); top: -100px; z-index: var(--z-toast);
  background: var(--surface); color: var(--text); padding: var(--sp-2) var(--sp-4);
  border-radius: var(--r-sm); box-shadow: var(--shadow-2);
}
.skip:focus { top: var(--sp-3); }
.sr-only { position: absolute !important; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.num { font-variant-numeric: tabular-nums; }
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; scroll-behavior: auto !important; }
}