/* ==========================================================
 * 文件: shared/reset.css
 * 版本: 0.1.0 · 更新: 2026-10-23 · 作者: Claude（为李泓锐）
 * 用途: 现代 CSS reset + 全局可访问性基线（焦点环、跳转链接、减少动效）
 * ========================================================== */

*,
*::before,
*::after {
  box-sizing: border-box;
}

* {
  margin: 0;
}

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  color-scheme: dark light;
}

/* overflow-x: clip 不会生成滚动容器，position: sticky 仍然有效 */
html,
body {
  overflow-x: clip;
}

body {
  min-height: 100dvh;
  font-family: var(--font-ui);
  font-size: var(--fs-md);
  line-height: var(--lh-body);
  color: var(--text-primary);
  background: var(--bg-base);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

img,
svg,
video,
canvas {
  display: block;
  max-width: 100%;
}

input,
button,
textarea,
select {
  font: inherit;
  color: inherit;
}

button {
  cursor: pointer;
  background: none;
  border: 0;
}

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

h1,
h2,
h3,
h4 {
  line-height: var(--lh-tight);
  text-wrap: balance;
}

p {
  text-wrap: pretty;
}

table {
  border-collapse: collapse;
  width: 100%;
}

/* 键盘焦点：只在键盘操作时显示，颜色读 tokens */
:focus-visible {
  outline: 2px solid var(--focus-ring);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

/* 仅读屏可见 */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* 跳到主内容：Tab 第一下出现 */
.skip-link {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 1000;
  padding: 10px 16px;
  border-radius: var(--radius-sm);
  background: var(--accent-primary);
  color: var(--accent-contrast);
  font-weight: 600;
  transform: translateY(-150%);
  transition: transform 0.2s;
}

.skip-link:focus {
  transform: translateY(0);
}

::selection {
  background: var(--selection, rgba(127, 127, 255, 0.35));
}

/* 系统开了「减少动态效果」：所有动画瞬间完成 */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}