/* ============================================================
 * base.css — 重置、排版、焦点、通用
 * ============================================================ */
*,
*::before,
*::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  /* 桌面端页面自身不滚动,滚动交给轨道(移动端在 responsive.css 覆盖) */
  height: 100%;
  overflow: hidden;
  -webkit-text-size-adjust: 100%;
}

body {
  height: 100%;
  background: var(--color-bg);
  color: var(--color-ink);
  font-family: var(--font-sans);
  font-size: var(--text-body);
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img {
  display: block;
  max-width: 100%;
  height: auto;
}

a {
  color: inherit;
  text-decoration: none;
}

ul, ol { list-style: none; }

button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  cursor: pointer;
}

/* 选中色 — 品牌细节 */
::selection {
  background: var(--color-selection-bg);
  color: var(--color-selection-fg);
}

/* 焦点可见性 — WCAG 2.4.7,全站唯一焦点样式 */
:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 2px;
}

/* 跳过链接 */
.skip-link {
  position: fixed;
  top: -48px;
  left: var(--station-pad-x);
  z-index: var(--z-overlay);
  padding: 8px 16px;
  background: var(--color-ink);
  color: var(--color-bg);
  font-size: var(--text-small);
  transition: top 0.2s var(--ease-out);
}
.skip-link:focus-visible { top: 8px; }

/* 数字:等宽数字字形(1087 等统计数) */
.num {
  font-family: var(--font-latin);
  font-variant-numeric: tabular-nums;
}

/* 隐藏滚动条(轨道专享)— 进度条承担位置指示 */
.scrollbar-hide { scrollbar-width: none; }
.scrollbar-hide::-webkit-scrollbar { display: none; }

/* 视觉减弱 — 全局关闭动效 */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  html { scroll-behavior: auto; }
}