/* 全局 reset 归零 —— 不引入任何 UI 框架，先把浏览器默认样式清空，
   再只用阶段 1 溯源表里的值逐项搭建。 */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html, body { height: 100%; }
body {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  font-feature-settings: normal;
  line-height: 1;
}
ul, ol { list-style: none; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; background: none; border: none; cursor: pointer; }
input, textarea, select { font: inherit; color: inherit; background: none; border: none; outline: none; }
img, svg { display: block; max-width: none; }
table { border-collapse: collapse; }
:focus { outline: none; }
/* 渲染区内禁止文本选中拖影，避免污染导出 */
.screen, .screen * { -webkit-user-select: none; user-select: none; }