/* =========================================================
   base.css — Reset / 基础排版 / 可用性底线
   ========================================================= */
*,
*::before,
*::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }
/* Lenis 接管后由 JS 添加 .lenis-smooth,原生 smooth 需关闭 */
html.lenis-smooth { scroll-behavior: auto; }
html.lenis-smooth body { height: auto; }

body {
  background: var(--color-bg);
  color: var(--color-ink);
  font-family: var(--font-zh-body);
  font-size: var(--fs-body);
  line-height: 1.9;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }
ul, ol, dl, dd { list-style: none; }
em, i { font-style: normal; }
strong { font-weight: 700; }

h1, h2, h3 {
  font-family: var(--font-zh-display);
  font-weight: 700;
  line-height: 1.3;
}

/* ---- 英文 / 数字装饰层 ---- */
.mono-label {
  font-family: var(--font-mono);
  font-size: var(--fs-label);
  letter-spacing: var(--tracking-label);
  text-transform: uppercase;
  color: var(--color-muted);
}

.vtext {
  writing-mode: vertical-rl;
  letter-spacing: .5em;
  font-size: 12px;
  color: var(--color-muted);
}

/* ---- 可用性 ---- */
::selection { background: var(--color-accent); color: var(--color-ink); }

:focus-visible {
  outline: 2px solid var(--color-ink);
  outline-offset: 3px;
}

.skip-link {
  position: fixed;
  top: -56px;
  left: 16px;
  z-index: var(--z-loading);
  background: var(--color-ink);
  color: var(--color-bg);
  padding: 10px 16px;
  font-size: 13px;
  transition: top var(--duration-fast) var(--ease-soft);
}
.skip-link:focus { top: 16px; }

.noscript {
  position: fixed;
  left: 16px;
  right: 16px;
  bottom: 16px;
  z-index: 999;
  background: var(--color-ink);
  color: var(--color-bg);
  padding: 16px 24px;
  text-align: center;
  font-size: 14px;
}

/* ---- 本地化字体 ---- */
@font-face {
  font-family: "Space Grotesk";
  src: url("../assets/fonts/space-grotesk-500.woff2") format("woff2");
  font-weight: 500;
  font-display: swap;
}
@font-face {
  font-family: "Space Grotesk";
  src: url("../assets/fonts/space-grotesk-700.woff2") format("woff2");
  font-weight: 700;
  font-display: swap;
}
@font-face {
  font-family: "IBM Plex Mono";
  src: url("../assets/fonts/ibm-plex-mono-400.woff2") format("woff2");
  font-weight: 400;
  font-display: swap;
}
@font-face {
  font-family: "IBM Plex Mono";
  src: url("../assets/fonts/ibm-plex-mono-500.woff2") format("woff2");
  font-weight: 500;
  font-display: swap;
}