/* ============================================================
   四季体育赛事 · 共享样式 /assets/site.css
   深场墨黑 + 四季撞色 · 展览画册式战报板
   ============================================================ */

/* ---------- 1. Reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

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

body,
h1, h2, h3, h4, h5, h6,
p, figure, blockquote,
ul, ol, dl, dd { margin: 0; }

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

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

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

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

summary { cursor: pointer; }

/* ---------- 2. 变量 ---------- */
:root {
  --ink: #0C0F14;
  --ink-2: #11151C;
  --panel: #161B23;
  --panel-2: #1C222C;

  --spring: #2BE08A;
  --summer: #FF6A1F;
  --autumn: #E8A33D;
  --winter: #45B8FF;

  --stone: #C9D2DC;
  --snow: #FFFFFF;
  --volt: #D8FF3E;
  --coral: #FF4D6D;

  --line: rgba(201, 210, 220, 0.16);
  --line-strong: rgba(201, 210, 220, 0.32);

  --radius-pill: 999px;
  --shadow-pop: 0 18px 44px rgba(0, 0, 0, 0.55);
  --shadow-hard: 4px 4px 0 rgba(0, 0, 0, 0.55);

  --font-sans: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, monospace;

  --w: 1200px;
  --gap: clamp(14px, 2.2vw, 24px);
  --dur: 0.24s;
  --ease: cubic-bezier(0.2, 0.8, 0.2, 1);
}

/* ---------- 3. 基础排版 ---------- */
body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  color: var(--stone);
  background-color: var(--ink);
  background-image:
    radial-gradient(1000px 620px at 92% -12%, rgba(69, 184, 255, 0.14), transparent 68%),
    radial-gradient(760px 480px at 2% 6%, rgba(43, 224, 138, 0.10), transparent 70%),
    radial-gradient(680px 420px at 70% 108%, rgba(255, 106, 31, 0.10), transparent 72%);
  min-height: 100vh;
}

/* 颗粒质感叠加层 */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 9990;
  pointer-events: none;
  background-image: radial-gradient(rgba(255, 255, 255, 0.055) 1px, transparent 1.6px);
  background-size: 3px 3px;
  opacity: 0.4;
}

::selection {
  background: var(--volt);
  color: var(--ink);
}

p { margin-bottom: 14px; }

#main-content { scroll-margin-top: 100px; }

/* ---------- 4. 文字层级 ---------- */
.display {
  font-family: var(--font-sans);
  font-weight: 900;
  line-height: 0.98;
  letter-spacing: -0.02em;
  color: var(--snow);
  text-wrap: balance;
}

.display--xl { font-size: clamp(2.6rem, 9vw, 5.5rem); }
.display--lg { font-size: clamp(2rem, 5.4vw, 3.25rem); }
.display--md { font-size: clamp(1.5rem, 3.2vw, 2.25rem); }

.tilt {
  display: inline-block;
  transform: skewX(-4deg);
}

.kicker {
  display: inline-flex;
  align-items: center;
  gap: 0.55em;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--winter);
}

.kicker::before {
  content: "";
  width: 18px;
  height: 2px;
  background: var(--volt);
  flex: 0 0 auto;
}

.lede {
  font-size: clamp(15px, 1.05vw, 17px);
  line-height: 1.8;
  color: #A9B4C2;
  max-width: 40em;
}

.mono {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.02em;
}

.annotation {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: rgba(201, 210, 220, 0.72);
  text-transform: uppercase;
}

.annotation--vertical {
  writing-mode: vertical-rl;
  text-orientation: mixed;
  letter-spacing: 0.34em;
}

/* ---------- 5. 布局 ---------- */
.container {
  width: 100%;
  max-width: var(--w);
  margin-inline: auto;
  padding-inline: clamp(16px, 4vw, 32px);
}

.section { padding-block: clamp(40px, 7vw, 88px); }

.stack {
  display: flex;
  flex-direction: column;
  gap: var(--gap);
}

.grid {
  display: grid;
  gap: var(--gap);
}

.grid--2 { grid-template-columns: 1fr; }
.grid--3 { grid-template-columns: 1fr; }

.grid--12 { grid-template-columns: repeat(12, minmax(0, 1fr)); }
.grid--12 > * { grid-column: span 12; min-width: 0; }

@media (min-width: 768px) {
  .grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .col-4 { grid-column: span 4; }
  .col-5 { grid-column: span 5; }
  .col-6 { grid-column: span 6; }
  .col-7 { grid-column: span 7; }
  .col-8 { grid-column: span 8; }
}

/* ---------- 6. 按钮 ---------- */
.btn {
  --btn-bg: transparent;
  --btn-fg: var(--snow);
  --btn-bd: var(--snow);
  --btn-shadow: rgba(0, 0, 0, 0.55);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.55em;
  padding: 13px 22px;
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 800;
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--btn-fg);
  background: var(--btn-bg);
  border: 2px solid var(--btn-bd);
  border-radius: var(--radius-pill);
  box-shadow: 4px 4px 0 var(--btn-shadow);
  white-space: nowrap;
  transition:
    transform 0.16s var(--ease),
    box-shadow 0.16s var(--ease),
    background-color 0.16s var(--ease),
    color 0.16s var(--ease),
    border-color 0.16s var(--ease);
}

.btn:hover {
  transform: translate(-2px, -2px);
  box-shadow: 6px 6px 0 var(--btn-shadow);
}

.btn:active {
  transform: translate(1px, 1px);
  box-shadow: 2px 2px 0 var(--btn-shadow);
}

.btn--action {
  --btn-bg: var(--summer);
  --btn-fg: var(--ink);
  --btn-bd: var(--ink);
  --btn-shadow: rgba(43, 224, 138, 0.9);
}

.btn--action:hover { --btn-bg: #FF8143; }

.btn--ghost {
  --btn-bg: transparent;
  --btn-fg: var(--snow);
  --btn-bd: var(--line-strong);
}

.btn--ghost:hover {
  --btn-bg: var(--volt);
  --btn-fg: var(--ink);
  --btn-bd: var(--volt);
}

.btn--sm {
  padding: 10px 16px;
  font-size: 13px;
  box-shadow: 3px 3px 0 var(--btn-shadow);
}

.btn--block {
  display: flex;
  width: 100%;
}

/* ---------- 7. 标签 / 面板 / 状态 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 0.4em;
  padding: 0.34em 0.75em;
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: 0.1em;
  line-height: 1;
  text-transform: uppercase;
  color: var(--stone);
  border: 1px solid currentColor;
  border-radius: var(--radius-pill);
  white-space: nowrap;
}

.tag--spring { color: var(--spring); }
.tag--summer { color: var(--summer); }
.tag--autumn { color: var(--autumn); }
.tag--winter { color: var(--winter); }
.tag--volt { color: var(--volt); }

.panel {
  position: relative;
  background: var(--panel);
  border: 2px solid var(--line-strong);
  border-radius: 2px;
  padding: clamp(16px, 2.2vw, 26px);
}

.panel--cut {
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 22px), calc(100% - 22px) 100%, 0 100%);
}

.status {
  display: inline-flex;
  align-items: center;
  gap: 0.5em;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: rgba(201, 210, 220, 0.86);
}

.status__dot {
  width: 8px;
  height: 8px;
  flex: 0 0 auto;
  border-radius: 50%;
  background: var(--spring);
  box-shadow: 0 0 0 3px rgba(43, 224, 138, 0.18);
}

.status__dot--live {
  background: var(--coral);
  box-shadow: 0 0 0 3px rgba(255, 77, 109, 0.2);
}

.status__dot--wait {
  background: var(--autumn);
  box-shadow: 0 0 0 3px rgba(232, 163, 61, 0.2);
}

/* ---------- 8. 面包屑 ---------- */
.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5em;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: rgba(201, 210, 220, 0.7);
}

.breadcrumbs__item {
  display: inline-flex;
  align-items: center;
  gap: 0.5em;
  min-width: 0;
}

.breadcrumbs__sep {
  color: rgba(201, 210, 220, 0.32);
}

.breadcrumbs a:hover { color: var(--volt); }
.breadcrumbs [aria-current="page"] { color: var(--snow); }

/* ---------- 9. 图片容器 ---------- */
.media {
  position: relative;
  display: block;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  background: var(--panel-2);
  border: 2px solid var(--line);
  border-radius: 2px;
  isolation: isolate;
}

.media > img,
.media > video {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(180deg, rgba(12, 15, 20, 0) 42%, rgba(12, 15, 20, 0.78) 100%);
}

.media--wide { aspect-ratio: 21 / 9; }
.media--4x3 { aspect-ratio: 4 / 3; }
.media--square { aspect-ratio: 1 / 1; }
.media--tall { aspect-ratio: 3 / 4; }

.media--spring { border-color: rgba(43, 224, 138, 0.55); }
.media--summer { border-color: rgba(255, 106, 31, 0.55); }
.media--autumn { border-color: rgba(232, 163, 61, 0.55); }
.media--winter { border-color: rgba(69, 184, 255, 0.55); }

.media--cut {
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 26px), calc(100% - 26px) 100%, 0 100%);
}

.media__caption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 1;
  padding: 12px 14px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--snow);
}

/* ---------- 10. 显现动画 ---------- */
[data-reveal] {
  transition: opacity 0.28s var(--ease), transform 0.28s var(--ease);
}

[data-reveal].reveal-pending {
  opacity: 0;
  transform: translateY(12px);
}

[data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

/* ---------- 11. 跳转链接 ---------- */
.skip-link {
  position: absolute;
  left: 12px;
  top: -72px;
  z-index: 500;
  padding: 10px 18px;
  font-weight: 800;
  font-size: 14px;
  color: var(--ink);
  background: var(--volt);
  border: 2px solid var(--ink);
  border-radius: var(--radius-pill);
  transition: top 0.2s var(--ease);
}

.skip-link:focus { top: 12px; }

/* ---------- 12. 头部 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  padding: 14px 12px 0;
}

.site-header__island {
  position: relative;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: 10px;
  width: 100%;
  max-width: var(--w);
  margin-inline: auto;
  padding: 8px 10px 8px 14px;
  background: linear-gradient(180deg, rgba(28, 34, 44, 0.97), rgba(20, 25, 33, 0.95));
  border: 2px solid var(--line-strong);
  border-radius: var(--radius-pill);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.55), inset 0 1px 0 rgba(255, 255, 255, 0.06);
  backdrop-filter: blur(14px) saturate(130%);
  -webkit-backdrop-filter: blur(14px) saturate(130%);
  transition:
    padding var(--dur) var(--ease),
    border-color var(--dur) var(--ease),
    box-shadow var(--dur) var(--ease);
}

/* 品牌 */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  flex: 0 0 auto;
  border-radius: var(--radius-pill);
}

.brand__mark {
  width: 36px;
  height: 36px;
  flex: 0 0 auto;
  display: grid;
  place-items: center;
  color: var(--volt);
  background: var(--ink);
  border: 2px solid var(--volt);
  border-radius: 11px;
  font-size: 12px;
  font-weight: 800;
  line-height: 1;
  letter-spacing: -0.04em;
  transform: rotate(-6deg);
  transition:
    transform var(--dur) var(--ease),
    background-color var(--dur) var(--ease),
    color var(--dur) var(--ease);
}

.brand:hover .brand__mark {
  transform: rotate(0deg);
  background: var(--volt);
  color: var(--ink);
}

.brand__text {
  display: flex;
  flex-direction: column;
  line-height: 1.15;
  min-width: 0;
}

.brand__name {
  font-size: 15px;
  font-weight: 900;
  letter-spacing: -0.01em;
  color: var(--snow);
}

.brand__tag {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: rgba(201, 210, 220, 0.62);
}

/* 导航 */
.site-nav {
  display: flex;
  justify-content: center;
  min-width: 0;
}

.site-nav__list {
  display: flex;
  align-items: center;
  gap: 2px;
  min-width: 0;
}

.site-nav__item { flex: 0 0 auto; }

.site-nav__link {
  display: inline-flex;
  align-items: center;
  max-width: 11em;
  overflow: hidden;
  padding: 8px 13px;
  font-size: 14px;
  font-weight: 600;
  color: var(--stone);
  white-space: nowrap;
  border: 1px solid transparent;
  border-radius: var(--radius-pill);
  transition:
    max-width var(--dur) var(--ease),
    padding var(--dur) var(--ease),
    opacity 0.18s linear,
    color 0.16s var(--ease),
    background-color 0.16s var(--ease),
    border-color 0.16s var(--ease);
}

.site-nav__link:hover {
  color: var(--volt);
  background: rgba(216, 255, 62, 0.1);
  border-color: rgba(216, 255, 62, 0.45);
}

.site-nav__link[aria-current="page"] {
  color: var(--ink);
  background: var(--volt);
  border-color: var(--volt);
  font-weight: 800;
  box-shadow: 2px 2px 0 rgba(0, 0, 0, 0.5);
}

/* 行动区 */
.site-header__actions {
  display: flex;
  align-items: center;
  gap: 8px;
  justify-self: end;
}

.header-cta { flex: 0 0 auto; }

.nav-toggle {
  display: none;
  width: 42px;
  height: 42px;
  flex: 0 0 auto;
  place-items: center;
  color: var(--snow);
  border: 2px solid var(--line-strong);
  border-radius: 50%;
  transition:
    color 0.16s var(--ease),
    border-color 0.16s var(--ease),
    background-color 0.16s var(--ease);
}

.nav-toggle:hover {
  color: var(--volt);
  border-color: var(--volt);
}

.nav-toggle__bars {
  display: grid;
  gap: 4px;
  width: 16px;
}

.nav-toggle__bars span {
  display: block;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform 0.2s var(--ease), opacity 0.16s linear;
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(2) {
  opacity: 0;
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}

/* 滚动进度 */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  z-index: 300;
  pointer-events: none;
  background: rgba(255, 255, 255, 0.06);
}

.scroll-progress__bar {
  display: block;
  width: 100%;
  height: 100%;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--spring), var(--volt) 52%, var(--summer));
}

/* 头部滚动状态 */
.site-header[data-scrolled="true"] .site-header__island {
  border-color: rgba(216, 255, 62, 0.35);
  box-shadow: 0 10px 24px rgba(0, 0, 0, 0.62);
}

@media (min-width: 960px) {
  .site-header[data-scrolled="true"] .site-nav__link:not([aria-current="page"]) {
    max-width: 0;
    padding-inline: 0;
    opacity: 0;
    border-color: transparent;
    pointer-events: none;
  }

  .site-header[data-scrolled="true"] .site-header__island:hover .site-nav__link,
  .site-header[data-scrolled="true"] .site-header__island:focus-within .site-nav__link {
    max-width: 11em;
    padding-inline: 13px;
    opacity: 1;
    pointer-events: auto;
  }
}

/* 移动端底部快捷栏（默认隐藏） */
.quick-bar { display: none; }

.quick-bar__link {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 3px;
  padding: 6px 2px;
  font-size: 10.5px;
  letter-spacing: 0.04em;
  color: rgba(201, 210, 220, 0.72);
  border-radius: 10px;
  transition: color 0.16s var(--ease), background-color 0.16s var(--ease);
}

.quick-bar__link:hover {
  color: var(--snow);
  background: rgba(255, 255, 255, 0.05);
}

.quick-bar__link[aria-current="page"] { color: var(--volt); }

.quick-bar__link svg {
  width: 20px;
  height: 20px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.7;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.quick-bar__label { line-height: 1; }

/* ---------- 13. 头部与快捷栏移动端 ---------- */
@media (max-width: 959px) {
  body { padding-bottom: 70px; }

  .site-header { padding: 10px 8px 0; }

  .site-header__island {
    gap: 8px;
    padding: 7px 8px 7px 12px;
  }

  .brand__tag { display: none; }

  .nav-toggle { display: grid; }

  .site-nav {
    position: absolute;
    top: calc(100% + 10px);
    left: 0;
    right: 0;
    display: none;
    padding: 10px;
    background: var(--panel);
    border: 2px solid var(--line-strong);
    border-radius: 20px;
    box-shadow: var(--shadow-pop);
    z-index: 20;
  }

  .site-nav[data-open="true"] { display: block; }

  .site-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
  }

  .site-nav__link {
    max-width: none;
    padding: 12px 14px;
    border-radius: 12px;
    font-size: 15px;
  }

  .site-nav__link[aria-current="page"] { box-shadow: none; }

  .header-cta {
    padding: 9px 14px;
    font-size: 12.5px;
  }

  .quick-bar {
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 150;
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 2px;
    padding: 6px 6px calc(6px + env(safe-area-inset-bottom, 0px));
    background: rgba(14, 18, 24, 0.97);
    border-top: 2px solid var(--line-strong);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
  }
}

@media (max-width: 420px) {
  .brand__mark { width: 32px; height: 32px; font-size: 11px; }
  .brand__name { font-size: 14px; }
  .header-cta { padding: 8px 12px; font-size: 12px; }
}

/* ---------- 14. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(48px, 8vw, 104px);
  border-top: 2px solid var(--line-strong);
  background: linear-gradient(180deg, rgba(22, 27, 35, 0.72) 0%, rgba(12, 15, 20, 0.98) 62%);
}

.site-footer::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 4px;
  background: linear-gradient(
    90deg,
    var(--spring) 0 25%,
    var(--summer) 25% 50%,
    var(--autumn) 50% 75%,
    var(--winter) 75% 100%
  );
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.35fr 1fr 1.25fr 0.85fr;
  gap: clamp(20px, 3vw, 44px);
  align-items: start;
  padding-block: clamp(34px, 5vw, 58px);
}

.footer-col {
  display: flex;
  flex-direction: column;
  gap: 12px;
  min-width: 0;
}

@media (min-width: 900px) {
  .footer-col--brand { padding-top: 4px; }
  .footer-col--legend { padding-top: 26px; }
}

.footer-brand {
  font-size: clamp(19px, 2vw, 22px);
  font-weight: 900;
  line-height: 1.2;
  letter-spacing: -0.01em;
  color: var(--snow);
}

.footer-tagline {
  font-size: 14px;
  line-height: 1.8;
  color: rgba(201, 210, 220, 0.78);
  max-width: 26em;
}

.footer-chip {
  align-self: flex-start;
  display: inline-flex;
  align-items: center;
  padding: 5px 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: rgba(201, 210, 220, 0.75);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-pill);
}

.footer-title {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--winter);
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.footer-link {
  width: fit-content;
  padding-block: 1px;
  font-size: 14px;
  color: rgba(201, 210, 220, 0.86);
  border-bottom: 1px solid transparent;
  transition: color 0.16s var(--ease), border-color 0.16s var(--ease);
}

.footer-link:hover {
  color: var(--volt);
  border-color: rgba(216, 255, 62, 0.6);
}

.footer-contact {
  display: grid;
  gap: 12px;
}

.footer-contact__item { display: grid; gap: 2px; }

.footer-contact__label {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: rgba(201, 210, 220, 0.55);
}

.footer-contact__value {
  font-size: 14px;
  color: var(--snow);
  word-break: break-word;
}

.footer-contact__value--mono {
  font-family: var(--font-mono);
  letter-spacing: 0.02em;
}

.footer-note {
  font-size: 12.5px;
  line-height: 1.75;
  color: rgba(201, 210, 220, 0.62);
  max-width: 30em;
  margin: 0;
}

.season-legend { display: grid; gap: 8px; }

.season-legend__item {
  display: flex;
  align-items: center;
  gap: 9px;
  font-size: 13px;
  color: rgba(201, 210, 220, 0.82);
}

.season-legend__dot {
  width: 11px;
  height: 11px;
  flex: 0 0 auto;
  border-radius: 2px;
  transform: rotate(45deg);
  background: var(--stone);
}

.dot--spring { background: var(--spring); }
.dot--summer { background: var(--summer); }
.dot--autumn { background: var(--autumn); }
.dot--winter { background: var(--winter); }

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 24px;
  padding-block: 18px 26px;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: rgba(201, 210, 220, 0.6);
}

.footer-copy,
.footer-icp { line-height: 1.6; margin: 0; }

@media (max-width: 899px) {
  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 559px) {
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 26px;
  }

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
  }
}

/* ---------- 15. 返回顶部 ---------- */
.to-top {
  position: fixed;
  right: 16px;
  bottom: 16px;
  z-index: 140;
  display: grid;
  place-items: center;
  width: 46px;
  height: 46px;
  color: var(--snow);
  background: var(--panel);
  border: 2px solid var(--line-strong);
  border-radius: 50%;
  box-shadow: var(--shadow-hard);
  opacity: 0;
  transform: translateY(10px);
  pointer-events: none;
  transition:
    opacity 0.2s var(--ease),
    transform 0.2s var(--ease),
    background-color 0.16s var(--ease),
    color 0.16s var(--ease),
    border-color 0.16s var(--ease);
}

.to-top[data-visible="true"] {
  opacity: 1;
  transform: none;
  pointer-events: auto;
}

.to-top:hover {
  color: var(--ink);
  background: var(--volt);
  border-color: var(--ink);
}

.to-top svg {
  width: 18px;
  height: 18px;
  fill: none;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

@media (max-width: 959px) {
  .to-top {
    right: 12px;
    bottom: 84px;
    width: 42px;
    height: 42px;
  }
}

/* ---------- 16. 焦点与动效偏好 ---------- */
:where(a, button, summary, [tabindex]):focus-visible {
  outline: 2px solid var(--volt);
  outline-offset: 3px;
  border-radius: 4px;
}

@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;
  }

  [data-reveal].reveal-pending {
    opacity: 1;
    transform: none;
  }
}