/* ==========================================================================
   BASE — 重置、根排版、焦点、降级动效
   ========================================================================== */

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

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

body {
  margin: 0;
  background-color: var(--color-bg);
  color: var(--color-text);
  font-family: "Noto Sans SC", "Chakra Petch", -apple-system, "PingFang SC",
               "Microsoft YaHei", sans-serif;
  font-size: var(--fs-base);
  line-height: var(--lh-body);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

/* 锁定滚动:预加载阶段与移动端菜单展开时 */
body.is-locked { overflow: hidden; }

h1, h2, h3, h4, p, figure, ul, ol {
  margin: 0;
  padding: 0;
}

ul, ol { list-style: none; }

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

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

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

/* ---------- 可见焦点圈:2px 描边 + 2px 偏移 --------------------------- */
:focus { outline: none; }

:focus-visible {
  outline: 2px solid var(--color-accent-soft);
  outline-offset: 3px;
  border-radius: var(--radius-xs);
}

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

/* ---------- 排版工具类 ---------------------------------------------- */
.mono {
  font-family: "IBM Plex Mono", ui-monospace, "SFMono-Regular", monospace;
  font-size: var(--fs-mono);
  letter-spacing: var(--track-wide);
  text-transform: uppercase;
  color: var(--color-muted);
  font-variant-numeric: tabular-nums;
}

/* 等宽数字:遥测数值防跳动 */
.tnum { font-variant-numeric: tabular-nums; }

.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;
}

/* ---------- 滚动揭示:只动 opacity / transform ----------------------- */
.reveal {
  opacity: 0;
  transform: translateY(26px);
  will-change: opacity, transform;
}

.reveal.is-in {
  opacity: 1;
  transform: none;
  transition:
    opacity var(--dur-slow) var(--ease-out),
    transform var(--dur-slow) var(--ease-out);
  transition-delay: var(--reveal-delay, 0ms);
}

/* 逐字揭示(用于品牌字样与宣言) */
.reveal-char {
  display: inline-block;
  opacity: 0;
  transform: translateY(0.55em) rotate(3deg);
  filter: blur(10px);
}

.is-in .reveal-char,
.reveal-char.is-in {
  opacity: 1;
  transform: none;
  filter: blur(0);
  transition:
    opacity var(--dur-slow) var(--ease-out),
    transform var(--dur-slow) var(--ease-out),
    filter var(--dur-slow) var(--ease-out);
  transition-delay: calc(var(--i, 0) * 70ms + var(--base-delay, 0ms));
}

/* ---------- 降级动效:尊重系统偏好 ----------------------------------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    animation-delay: 0s !important;
    transition-duration: 0.001ms !important;
    transition-delay: 0s !important;
  }

  .reveal,
  .reveal-char {
    opacity: 1 !important;
    transform: none !important;
    filter: none !important;
  }

  .cursor,
  .cursor-ring { display: none !important; }
}