/* 全站共用外壳：背景、导航、备案栏。只引用 design-tokens.css，不另定义字体/字号/颜色值。 */

* { box-sizing: border-box; }

html,
body {
  width: 100%;
  min-width: 800px;
  min-height: 100%;
  margin: 0;
}

body {
  min-height: 100svh;
  overflow: hidden;
  background:
    radial-gradient(
      circle var(--top-circle-spread) at var(--top-circle-x) var(--top-circle-y),
      var(--top-circle-color) 0%,
      color-mix(in srgb, var(--top-circle-color) 72%, transparent) 18%,
      transparent 70%
    ),
    radial-gradient(
      circle var(--bottom-circle-spread) at var(--bottom-circle-x) var(--bottom-circle-y),
      var(--bottom-circle-color) 0%,
      color-mix(in srgb, var(--bottom-circle-color) 64%, transparent) 18%,
      transparent 70%
    ),
    linear-gradient(
      var(--gradient-angle),
      var(--gradient-start-color) 0%,
      var(--gradient-end-color) 100%
    );
}

body.notes-site::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  /* Fade the same background in grayscale, avoiding animated backdrop sampling. */
  background: inherit;
  filter: grayscale(1);
  opacity: 1;
  animation: notes-page-desaturate var(--background-desaturate-duration) var(--background-desaturate-ease) both;
}

@keyframes notes-page-desaturate {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

@media (prefers-reduced-motion: reduce) {
  body.notes-site::before {
    animation: none;
    opacity: 1;
  }
}

.grain {
  position: fixed;
  inset: 0;
  pointer-events: none;
  background: url("../img/grain.png") repeat;
  background-size: var(--grain-size) var(--grain-size);
  opacity: var(--grain-strength);
  filter: contrast(var(--grain-contrast));
  mix-blend-mode: soft-light;
}

.site-header {
  position: fixed;
  top: var(--site-nav-top);
  left: var(--site-nav-right);
  right: var(--site-nav-right);
  z-index: 3;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.site-brand {
  display: inline-flex;
  flex: 0 0 auto;
  align-items: center;
  min-width: 40px;
  min-height: 40px;
  color: var(--site-nav-text);
  text-decoration: none;
}

.site-brand-mark {
  display: block;
  flex: 0 0 auto;
  width: calc(var(--site-brand-logo-size) * 10 / 11);
  height: var(--site-brand-logo-size);
  fill: currentColor;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: var(--site-nav-gap);
}

.site-nav-link {
  position: relative;
  display: block;
  flex: 0 0 auto;
  margin: 0;
  padding: 8px 0;
  border: 0;
  appearance: none;
  background: transparent;
  cursor: pointer;
  color: var(--site-nav-text);
  font-family: var(--font-family-ui);
  font-size: var(--site-nav-font-size);
  font-weight: var(--font-weight-regular);
  text-decoration: none;
  -webkit-tap-highlight-color: transparent;
}

.site-nav-link[aria-disabled="true"] {
  cursor: not-allowed;
}

.site-nav-label {
  display: block;
  height: var(--site-nav-line-height);
  overflow: hidden;
}

.site-nav-track {
  display: grid;
  grid-template-rows: repeat(2, var(--site-nav-line-height));
  transform: translateY(0);
  transition: transform var(--site-nav-duration) var(--site-nav-ease);
}

.site-nav-track > span {
  display: block;
  line-height: var(--site-nav-line-height);
  text-align: center;
  white-space: nowrap;
}

.site-nav-track > [lang="en"] {
  letter-spacing: var(--site-nav-en-spacing);
}

.site-nav-track > [lang="zh-CN"] {
  letter-spacing: var(--site-nav-zh-spacing);
}

.site-nav-link::after {
  content: "";
  position: absolute;
  top: 4px;
  right: -10px;
  width: var(--site-nav-marker-size);
  height: var(--site-nav-marker-size);
  background: currentColor;
  opacity: 0;
  transform: scale(0);
  transform-origin: center;
  transition: transform var(--site-nav-duration) var(--site-nav-ease), opacity var(--site-nav-marker-fade-duration) ease;
  pointer-events: none;
}

.site-nav-link:is(:hover, :focus-visible, [aria-current="page"], .is-pending) .site-nav-track {
  transform: translateY(-50%);
}

.site-nav-link:not([aria-disabled="true"]):is(:hover, :focus-visible, [aria-current="page"], .is-pending)::after {
  opacity: 1;
  transform: scale(1);
}

/* 切换时旧选项向下回到英文，即使仍有焦点，也不留在中文状态。 */
.site-nav.is-switching .site-nav-link:not(.is-pending) .site-nav-track {
  transform: translateY(0);
}

.site-nav.is-switching .site-nav-link:not(.is-pending)::after {
  opacity: 0;
  transform: scale(0);
}

.site-brand:focus-visible,
.site-nav-link:focus-visible {
  outline: 1px solid var(--color-focus-ring);
  outline-offset: 7px;
}

@media (prefers-reduced-motion: reduce) {
  .site-nav-track,
  .site-nav-link::after {
    transition: none;
  }
}

.record-bar {
  position: fixed;
  left: 50%;
  right: auto;
  width: calc(100% - 320px);
  max-width: 1600px;
  bottom: max(16px, env(safe-area-inset-bottom));
  z-index: 2;
  min-width: 768px;
  min-height: var(--record-bar-height);
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 18px;
  padding: 0 22px 0 8px;
  border: 1px solid var(--record-bar-border);
  border-radius: 999px;
  color: var(--record-bar-text);
  background: color-mix(
    in srgb,
    var(--record-bar-background) var(--record-bar-background-opacity),
    transparent
  );
  box-shadow: 0 8px 24px var(--color-shadow);
  font-family: var(--font-family-ui);
  font-size: var(--record-bar-font-size);
  font-weight: var(--font-weight-regular);
  line-height: 1;
  white-space: nowrap;
  transform: translateX(-50%);
}

.record-bar a {
  color: inherit;
  text-decoration: none;
}

.record-bar-brand {
  justify-self: start;
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.record-bar-avatar {
  width: var(--record-bar-avatar-size);
  height: var(--record-bar-avatar-size);
  border-radius: 50%;
  object-fit: cover;
}

.record-bar-icp { justify-self: center; }

.record-bar-police {
  justify-self: end;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.record-bar-police img {
  width: 13px;
  height: 13px;
}

.record-bar a:focus-visible {
  outline: 1px solid var(--color-focus-ring);
  outline-offset: 4px;
}