/* ==========================================================================
   base.css — 重置、氛围层、排版基线、可访问性
   ========================================================================== */

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

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

body {
  margin: 0;
  min-height: 100svh;
  background: var(--c-bg);
  color: var(--c-text);
  font-family: var(--font-body);
  font-size: var(--fs-body);
  line-height: 1.75;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

img {
  display: block;
  max-width: 100%;
  height: auto;
}

h1,
h2,
h3,
h4,
p,
figure,
blockquote {
  margin: 0;
}

ul,
ol {
  margin: 0;
  padding: 0;
  list-style: none;
}

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

button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  padding: 0;
  cursor: pointer;
}

/* 关键：组件里的 display 会覆盖 UA 的 [hidden]{display:none}，
   导致 JS 用 hidden 属性藏起来的元素照常显示。必须强制。 */
[hidden] {
  display: none !important;
}

/* ---------- 氛围层：光晕 → 网格 → 颗粒 ----------
   三层都是 fixed + pointer-events:none，不参与布局，
   滚动时保持不动，形成「内容在玻璃后滑动」的观感。 */

.layer-sky {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background:
    radial-gradient(
      68rem 44rem at 6% -14%,
      rgba(255, 92, 43, 0.3),
      transparent 62%
    ),
    radial-gradient(
      46rem 36rem at 104% 10%,
      rgba(255, 46, 126, 0.14),
      transparent 60%
    ),
    radial-gradient(
      64rem 48rem at 50% 118%,
      rgba(255, 196, 107, 0.06),
      transparent 66%
    );
}

.layer-grid {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image:
    linear-gradient(to right, var(--c-grid) 1px, transparent 1px),
    linear-gradient(to bottom, var(--c-grid) 1px, transparent 1px);
  background-size: 40px 40px;
  /* 网格随视口向下淡出，避免整屏均匀噪点 */
  -webkit-mask-image: radial-gradient(
    ellipse 120% 90% at 50% 0%,
    #000 30%,
    transparent 88%
  );
  mask-image: radial-gradient(
    ellipse 120% 90% at 50% 0%,
    #000 30%,
    transparent 88%
  );
}

.layer-grain {
  position: fixed;
  inset: 0;
  z-index: 2;
  pointer-events: none;
  opacity: 0.045;
  mix-blend-mode: overlay;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='3'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

/* 内容层统一抬到氛围层之上 */
.site-header,
main,
.site-footer,
.dock {
  position: relative;
  z-index: 1;
}

/* ---------- 排版基线 ---------- */
h1,
h2,
h3 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.02em;
  text-wrap: balance;
}

p {
  text-wrap: pretty;
}

/* 等宽工具类：全站「数据感」的唯一来源 */
.mono {
  font-family: var(--font-mono);
  font-size: var(--fs-mono);
  letter-spacing: 0.16em;
  text-transform: uppercase;
  font-variant-numeric: tabular-nums;
  color: var(--c-muted);
}

.mono--lg {
  font-size: var(--fs-mono-lg);
}

/* ---------- 可访问性 ---------- */
.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;
}

.skip-link {
  position: absolute;
  top: -100px;
  left: var(--gutter);
  z-index: 99;
  padding: var(--s-3) var(--s-5);
  background: var(--c-surface-2);
  border: 1px solid var(--c-accent);
  border-radius: var(--r-sm);
  font-size: var(--fs-sm);
  transition: top var(--dur-fast) ease-out;
}

.skip-link:focus-visible {
  top: var(--s-3);
}

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

::selection {
  background: var(--c-accent-a35);
  color: var(--c-text);
}

/* ---------- 滚动条（桌面端细节）---------- */
@media (pointer: fine) {
  ::-webkit-scrollbar {
    width: 10px;
  }
  ::-webkit-scrollbar-track {
    background: var(--c-bg);
  }
  ::-webkit-scrollbar-thumb {
    background: #22242b;
    border: 2px solid var(--c-bg);
    border-radius: var(--r-full);
  }
  ::-webkit-scrollbar-thumb:hover {
    background: #31343d;
  }
}

/* ---------- 降级：尊重系统减少动态偏好 ----------
   一处统一关闭，组件层不需要各自再写一遍。 */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }

  /* 入场元素直接显示，绝不留半透明残影 */
  .reveal {
    opacity: 1 !important;
    transform: none !important;
  }

  /* 跑马灯改为可手动横向滚动 */
  .marquee {
    overflow-x: auto;
  }
  .marquee__track {
    transform: none !important;
  }
}