/* ============================================================
   Reset & Base —— 归一化与全局排版
   ============================================================ */
*,
*::before,
*::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  font-family: var(--font-sans);
  font-size: var(--fs-body);
  line-height: 1.75;
  color: var(--ink-900);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

img, picture, video, svg { display: block; max-width: 100%; height: auto; }

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

ul, ol { list-style: none; }

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

h1, h2, h3, h4 { font-family: var(--font-serif); font-weight: 700; line-height: 1.25; }

::selection { background: var(--red-600); color: #fff; }

/* 滚动条（桌面端点缀） */
::-webkit-scrollbar { width: 10px; }
::-webkit-scrollbar-track { background: var(--paper-2); }
::-webkit-scrollbar-thumb { background: var(--red-600); border-radius: 999px; }

/* 无障碍：减少动效偏好 */
@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; scroll-behavior: auto !important; }
}