/* ==========================================================================
   完美电竞台 · 共享样式表 /assets/site.css
   深空紫底 + 精密网格 + Bento 信息板 + 命令栏导航
   ========================================================================== */

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

:root {
  --void: #0A0A1C;
  --void-deep: #07070F;
  --panel: #101A38;
  --indigo: #241A55;
  --archive: #0B2E2C;
  --alert: #3A1122;
  --cyan: #35F0DC;
  --orange: #FF8A3C;
  --up: #6BF2A2;
  --down: #FF6E8E;
  --ink: #EFF1FA;
  --muted: #9AA1C9;
  --line: #2A2E52;
  --index: #4D548A;

  --shell: 1320px;
  --pad: 48px;
  --bar-h: 76px;

  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
  --r: 2px;

  --sans: system-ui, -apple-system, "Segoe UI", "PingFang SC", "Hiragino Sans GB",
          "Microsoft YaHei", "Source Han Sans SC", "Noto Sans CJK SC", sans-serif;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas,
          "Liberation Mono", "Courier New", monospace;
}

@media (max-width: 1024px) {
  :root { --pad: 32px; --bar-h: 70px; }
}
@media (max-width: 640px) {
  :root { --pad: 20px; --bar-h: 62px; }
}

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

body {
  margin: 0;
  background-color: var(--void);
  background-image:
    radial-gradient(120% 70% at 12% -8%, rgba(36, 26, 85, 0.85) 0%, rgba(10, 10, 28, 0) 62%),
    radial-gradient(90% 60% at 100% 4%, rgba(11, 46, 44, 0.5) 0%, rgba(10, 10, 28, 0) 58%);
  background-repeat: no-repeat;
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16.5px;
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(42, 46, 82, 0.55) 1px, transparent 1px),
    linear-gradient(90deg, rgba(42, 46, 82, 0.55) 1px, transparent 1px);
  background-size: 88px 88px;
  opacity: 0.22;
  -webkit-mask-image: radial-gradient(120% 88% at 50% 0%, #000 0%, rgba(0, 0, 0, 0) 78%);
  mask-image: radial-gradient(120% 88% at 50% 0%, #000 0%, rgba(0, 0, 0, 0) 78%);
}

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

a { color: var(--cyan); text-decoration: none; }
a:hover { color: var(--orange); }

h1, h2, h3, h4 { color: var(--ink); margin: 0; }
p { margin: 0 0 1em; }
ul, ol { margin: 0; padding: 0; }

button { font: inherit; color: inherit; }

::selection { background: var(--cyan); color: #05121B; }

:focus-visible {
  outline: 2px solid var(--orange);
  outline-offset: 2px;
  border-radius: 1px;
}

/* ---------- 跳过链接 ---------- */
.sl-skip {
  position: absolute;
  left: 12px;
  top: -72px;
  z-index: 200;
  padding: 10px 18px;
  background: var(--cyan);
  color: #05121B;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.04em;
  border-radius: var(--r);
  transition: top 0.2s var(--ease);
}
.sl-skip:focus { top: 12px; color: #05121B; }

/* ---------- 容器 ---------- */
.shell {
  width: 100%;
  max-width: var(--shell);
  margin: 0 auto;
  padding-inline: var(--pad);
  position: relative;
  z-index: 1;
}
.shell--narrow { max-width: 880px; }

/* ==========================================================================
   命令栏头部
   ========================================================================== */
.cmd-bar {
  position: sticky;
  top: 0;
  z-index: 80;
  background: rgba(10, 10, 28, 0.92);
  -webkit-backdrop-filter: blur(14px) saturate(140%);
  backdrop-filter: blur(14px) saturate(140%);
  border-bottom: 1px solid var(--line);
}
.cmd-bar::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 1px;
  background: linear-gradient(90deg, var(--cyan) 0%, rgba(53, 240, 220, 0) 34%, rgba(255, 138, 60, 0) 62%, var(--orange) 100%);
  opacity: 0.55;
}

.cmd-bar__inner {
  max-width: var(--shell);
  margin: 0 auto;
  padding-inline: var(--pad);
  height: var(--bar-h);
  display: flex;
  align-items: center;
  gap: 22px;
}

/* 品牌 */
.cmd-brand {
  display: flex;
  align-items: center;
  gap: 14px;
  flex: 0 0 auto;
}
.cmd-brand__link {
  display: flex;
  align-items: center;
  gap: 11px;
  color: inherit;
}
.cmd-brand__link:hover { color: inherit; }

.cmd-brand__mark {
  width: 36px;
  height: 36px;
  display: grid;
  place-items: center;
  flex: 0 0 auto;
  background: var(--indigo);
  border: 1px solid rgba(53, 240, 220, 0.55);
  color: var(--cyan);
  font-size: 16px;
  font-weight: 900;
  line-height: 1;
  clip-path: polygon(0 0, 100% 0, 100% 74%, 74% 100%, 0 100%);
}

.cmd-brand__text { display: block; }
.cmd-brand__name {
  display: block;
  font-size: 18px;
  font-weight: 900;
  letter-spacing: 0.05em;
  line-height: 1.15;
}
.cmd-brand__desc {
  display: block;
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--muted);
  line-height: 1.5;
  white-space: nowrap;
}

.cmd-status {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 9px;
  border: 1px solid rgba(53, 240, 220, 0.35);
  background: rgba(53, 240, 220, 0.06);
  color: var(--cyan);
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.18em;
  line-height: 1.6;
  border-radius: 1px;
  white-space: nowrap;
}
.cmd-status__dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--cyan);
  animation: cmdPulse 2.2s var(--ease) infinite;
}
@keyframes cmdPulse {
  0%   { box-shadow: 0 0 0 0 rgba(53, 240, 220, 0.55); }
  70%  { box-shadow: 0 0 0 7px rgba(53, 240, 220, 0); }
  100% { box-shadow: 0 0 0 0 rgba(53, 240, 220, 0); }
}

/* 导航 */
.cmd-nav { margin-left: auto; }
.cmd-nav__list {
  display: flex;
  align-items: center;
  gap: 2px;
  list-style: none;
}
.cmd-nav__link {
  position: relative;
  display: inline-flex;
  align-items: baseline;
  gap: 7px;
  padding: 9px 12px;
  font-size: 14.5px;
  font-weight: 500;
  color: var(--muted);
  border: 1px solid transparent;
  border-radius: var(--r);
  transition: color 0.18s var(--ease), background-color 0.18s var(--ease),
              border-color 0.18s var(--ease);
}
.cmd-nav__link::before {
  content: attr(data-idx);
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.08em;
  color: var(--index);
  transition: color 0.18s var(--ease);
}
.cmd-nav__link::after {
  content: "";
  position: absolute;
  left: 12px;
  right: 12px;
  bottom: 3px;
  height: 1px;
  background: var(--cyan);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.22s var(--ease);
}
.cmd-nav__link:hover,
.cmd-nav__link:focus-visible {
  color: var(--ink);
  background: rgba(53, 240, 220, 0.07);
  border-color: rgba(53, 240, 220, 0.18);
}
.cmd-nav__link:hover::before { color: var(--cyan); }

.cmd-nav__link[aria-current="page"] {
  color: var(--cyan);
  background: rgba(53, 240, 220, 0.09);
  border-color: rgba(53, 240, 220, 0.34);
}
.cmd-nav__link[aria-current="page"]::before { color: var(--cyan); }
.cmd-nav__link[aria-current="page"]::after { transform: scaleX(1); }

/* 行动区 */
.cmd-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: 0 0 auto;
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 18px;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.03em;
  line-height: 1.4;
  color: var(--ink);
  background: transparent;
  border: 1px solid var(--line);
  border-radius: var(--r);
  cursor: pointer;
  white-space: nowrap;
  transition: background-color 0.18s var(--ease), border-color 0.18s var(--ease),
              color 0.18s var(--ease), transform 0.18s var(--ease);
}
.btn:hover { color: var(--ink); transform: translateY(-1px); }
.btn--primary {
  background: var(--cyan);
  border-color: var(--cyan);
  color: #05121B;
}
.btn--primary:hover {
  background: #5CFBE8;
  border-color: var(--orange);
  color: #05121B;
  box-shadow: 0 0 0 1px var(--orange);
}
.btn--ghost {
  color: var(--cyan);
  border-color: rgba(53, 240, 220, 0.34);
}
.btn--ghost:hover {
  color: var(--orange);
  border-color: var(--orange);
  background: rgba(255, 138, 60, 0.08);
}

/* ---------- 移动导航按钮 ---------- */
.nav-toggle {
  display: none;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 40px;
  padding: 0;
  background: rgba(16, 26, 56, 0.6);
  border: 1px solid var(--line);
  border-radius: var(--r);
  cursor: pointer;
  transition: border-color 0.18s var(--ease), background-color 0.18s var(--ease);
}
.nav-toggle:hover { border-color: var(--cyan); background: rgba(53, 240, 220, 0.08); }
.nav-toggle__bar {
  display: block;
  width: 18px;
  height: 2px;
  background: var(--ink);
  transition: transform 0.2s var(--ease), opacity 0.2s var(--ease), background-color 0.2s var(--ease);
}
.nav-toggle:hover .nav-toggle__bar { background: var(--cyan); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---------- 头部响应式 ---------- */
@media (max-width: 1240px) {
  .cmd-brand__desc { display: none; }
  .cmd-nav__link { padding: 9px 9px; font-size: 14px; }
  .cmd-nav__link::before { display: none; }
}

@media (max-width: 1080px) {
  .cmd-brand__text { display: flex; align-items: baseline; gap: 10px; }
  .cmd-status { display: none; }
  .cmd-nav {
    position: fixed;
    left: 0;
    right: 0;
    top: var(--bar-h);
    z-index: 79;
    margin: 0;
    padding: 10px var(--pad) 22px;
    background: var(--void-deep);
    border-bottom: 1px solid var(--line);
    box-shadow: 0 24px 48px rgba(0, 0, 0, 0.55);
    max-height: calc(100vh - var(--bar-h));
    overflow-y: auto;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-12px);
    transition: opacity 0.2s var(--ease), transform 0.26s var(--ease), visibility 0.2s linear;
  }
  .cmd-nav[data-open] {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
  }
  .cmd-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }
  .cmd-nav__link {
    justify-content: space-between;
    padding: 14px 6px;
    font-size: 16px;
    border: 0;
    border-bottom: 1px solid var(--line);
    border-radius: 0;
  }
  .cmd-nav__link::before { display: block; }
  .cmd-nav__link::after { display: none; }
  .cmd-nav__link:hover { background: rgba(53, 240, 220, 0.05); }
  .cmd-nav__link[aria-current="page"] {
    background: transparent;
    border-color: transparent;
    border-bottom-color: var(--line);
    box-shadow: inset 3px 0 0 var(--cyan);
    padding-left: 16px;
  }
  .nav-toggle { display: flex; }
  body[data-nav-open="true"] { overflow: hidden; }
  body[data-nav-open="true"] .cmd-nav { opacity: 1; visibility: visible; }
}

@media (max-width: 560px) {
  .cmd-brand__mark { width: 32px; height: 32px; font-size: 14px; }
  .cmd-brand__name { font-size: 16px; }
  .cmd-actions .btn--ghost { display: none; }
  .cmd-actions .btn--primary { padding: 9px 13px; font-size: 13px; }
}

/* ==========================================================================
   页脚 · 值班台
   ========================================================================== */
.dock {
  position: relative;
  margin-top: 96px;
  background: linear-gradient(180deg, rgba(10, 10, 28, 0) 0%, var(--void-deep) 46%, #05050B 100%);
  border-top: 1px solid var(--line);
}
.dock::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  width: 160px;
  height: 1px;
  background: var(--cyan);
}
.dock__inner { padding-block: 58px 28px; }

.dock__grid {
  display: grid;
  grid-template-columns: 1.5fr 0.9fr 0.9fr 0.9fr 1.7fr;
  gap: 34px;
  align-items: start;
}

.dock__logo {
  display: inline-block;
  font-size: 22px;
  font-weight: 900;
  letter-spacing: 0.06em;
  color: var(--ink);
}
.dock__logo:hover { color: var(--cyan); }

.dock__tag {
  margin: 14px 0 16px;
  max-width: 30ch;
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
}

.dock__chips { display: flex; flex-wrap: wrap; gap: 8px; }

.chip {
  display: inline-block;
  padding: 4px 10px;
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.14em;
  color: var(--muted);
  border: 1px solid var(--line);
  background: rgba(16, 26, 56, 0.55);
  clip-path: polygon(0 0, 100% 0, 100% 66%, 88% 100%, 0 100%);
}
.chip--cyan {
  color: var(--cyan);
  border-color: rgba(53, 240, 220, 0.4);
  background: rgba(53, 240, 220, 0.07);
}

.dock__col { min-width: 0; }

.dock__title {
  margin: 0 0 16px;
  padding-left: 12px;
  position: relative;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.2em;
  line-height: 1.6;
  color: var(--muted);
}
.dock__title::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.62em;
  width: 6px;
  height: 1px;
  background: var(--cyan);
}

.dock__list { list-style: none; display: grid; gap: 10px; }
.dock__link {
  display: inline-block;
  font-size: 14.5px;
  color: var(--ink);
  transition: color 0.18s var(--ease), transform 0.18s var(--ease);
}
.dock__link:hover { color: var(--cyan); transform: translateX(3px); }

.dock__contact {
  margin: 0;
  display: grid;
  gap: 2px;
  font-size: 14px;
}
.dock__contact dt {
  padding-top: 12px;
  font-size: 10.5px;
  letter-spacing: 0.18em;
  color: var(--index);
  line-height: 1.7;
}
.dock__contact dt:first-of-type { padding-top: 0; }
.dock__contact dd {
  margin: 0;
  color: var(--ink);
  line-height: 1.7;
  word-break: break-word;
}
.dock__contact .num { color: var(--cyan); letter-spacing: 0.04em; }

.dock__base {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 26px;
  margin-top: 48px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
  font-size: 12.5px;
  color: var(--muted);
}
.dock__base p { margin: 0; }
.dock__legal { letter-spacing: 0.06em; }
.dock__sig { color: rgba(154, 161, 201, 0.82); }
.dock__year { color: var(--index); }

@media (max-width: 1180px) {
  .dock__grid { grid-template-columns: 1fr 1fr 1fr; gap: 38px 28px; }
  .dock__brand { grid-column: 1 / -1; }
  .dock__col--contact { grid-column: 1 / -1; max-width: 560px; }
}
@media (max-width: 760px) {
  .dock { margin-top: 64px; }
  .dock__grid { grid-template-columns: 1fr 1fr; gap: 32px 22px; }
  .dock__inner { padding-block: 44px 24px; }
}
@media (max-width: 460px) {
  .dock__grid { grid-template-columns: 1fr; }
  .dock__base { flex-direction: column; align-items: flex-start; gap: 8px; }
}

/* ==========================================================================
   通用排版与区块
   ========================================================================== */
.display {
  font-size: clamp(44px, 7vw, 128px);
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 0.94;
  margin: 0;
}

.num {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-feature-settings: "tnum" 1;
}

.sec { padding-block: 72px; }
.sec--tight { padding-block: 44px; }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 16px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.24em;
  color: var(--cyan);
  line-height: 1.6;
}
.eyebrow::before {
  content: "";
  width: 24px;
  height: 1px;
  background: var(--cyan);
  flex: 0 0 auto;
}

.sec-title {
  font-size: clamp(26px, 3vw, 44px);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.01em;
  margin: 0 0 14px;
}

.sec-lede {
  max-width: 68ch;
  color: var(--muted);
  margin: 0;
}

.rule {
  height: 1px;
  border: 0;
  margin: 0;
  background: var(--line);
}

/* 正文长文 */
.prose { max-width: 68ch; }
.prose > * + * { margin-top: 0; }
.prose p { margin: 0 0 1.1em; }
.prose h2 {
  font-size: clamp(22px, 2.2vw, 30px);
  font-weight: 700;
  line-height: 1.25;
  margin: 2em 0 0.6em;
}
.prose h3 { font-size: 19px; font-weight: 700; margin: 1.6em 0 0.5em; }
.prose ul, .prose ol { margin: 0 0 1.1em; padding-left: 1.25em; }
.prose li { margin: 0.4em 0; }
.prose strong { color: var(--ink); font-weight: 700; }
.prose code {
  font-family: var(--mono);
  font-size: 0.88em;
  padding: 1px 5px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 1px;
}

/* 面包屑 */
.crumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--muted);
}
.crumb li { display: flex; align-items: center; }
.crumb li + li::before {
  content: "/";
  margin: 0 10px;
  color: var(--line);
}
.crumb a { color: var(--muted); }
.crumb a:hover { color: var(--cyan); }
.crumb [aria-current="page"] { color: var(--ink); }

/* 标签 */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 9px;
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.14em;
  line-height: 1.6;
  color: var(--muted);
  background: rgba(16, 26, 56, 0.6);
  border: 1px solid var(--line);
  border-radius: 1px;
  white-space: nowrap;
}
.tag--live { color: var(--cyan); border-color: rgba(53, 240, 220, 0.42); background: rgba(53, 240, 220, 0.07); }
.tag--alert { color: var(--orange); border-color: rgba(255, 138, 60, 0.42); background: rgba(255, 138, 60, 0.07); }
.tag--up { color: var(--up); border-color: rgba(107, 242, 162, 0.42); background: rgba(107, 242, 162, 0.07); }
.tag--down { color: var(--down); border-color: rgba(255, 110, 142, 0.42); background: rgba(255, 110, 142, 0.07); }

/* Bento 信息板 */
.bento {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: 14px;
}
.bento__cell {
  position: relative;
  min-width: 0;
  padding: 22px;
  background: var(--panel);
  border: 1px solid var(--line);
}
.bento__cell--indigo { background: var(--indigo); border-color: rgba(133, 118, 226, 0.32); }
.bento__cell--archive { background: var(--archive); border-color: rgba(53, 240, 220, 0.22); }
.bento__cell--alert { background: var(--alert); border-color: rgba(255, 110, 142, 0.28); }

@media (max-width: 900px) {
  .bento { grid-template-columns: repeat(6, minmax(0, 1fr)); }
}
@media (max-width: 560px) {
  .bento { grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 10px; }
  .bento__cell { padding: 16px; }
}

/* 图片容器（页面阶段放置 img） */
.media-frame {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  background: var(--panel);
  border: 1px solid var(--line);
}
.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--tall { aspect-ratio: 3 / 4; }
.media-frame--square { aspect-ratio: 1 / 1; }

.media-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(1.06) contrast(1.04);
}

.media-frame__ph {
  position: absolute;
  inset: 0;
  background-image: repeating-linear-gradient(
    135deg,
    rgba(42, 46, 82, 0.55) 0 1px,
    transparent 1px 12px
  );
  background-color: rgba(16, 26, 56, 0.7);
}

.media-frame__scan {
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: repeating-linear-gradient(
    180deg,
    rgba(53, 240, 220, 0.07) 0 1px,
    transparent 1px 4px
  );
  mix-blend-mode: screen;
  animation: scanDrift 9s linear infinite;
}
@keyframes scanDrift {
  from { transform: translateY(0); }
  to { transform: translateY(8px); }
}

.media-frame__cap {
  position: absolute;
  left: 0;
  bottom: 0;
  max-width: 100%;
  padding: 6px 12px;
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.14em;
  line-height: 1.6;
  color: var(--ink);
  background: rgba(10, 10, 28, 0.8);
  border-top: 1px solid var(--line);
  border-right: 1px solid var(--line);
}

/* 章节目录 */
.toc { list-style: none; display: grid; gap: 2px; }
.toc a {
  display: block;
  padding: 7px 10px;
  font-size: 13.5px;
  color: var(--muted);
  border-left: 1px solid var(--line);
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease), background-color 0.18s var(--ease);
}
.toc a:hover { color: var(--ink); background: rgba(16, 26, 56, 0.6); }
.toc a[aria-current="true"] {
  color: var(--cyan);
  border-left-color: var(--cyan);
  background: rgba(53, 240, 220, 0.07);
}

/* ==========================================================================
   滚动进度轨与返回顶部
   ========================================================================== */
.scroll-rail {
  position: fixed;
  left: 0;
  right: 0;
  top: 0;
  height: 2px;
  z-index: 90;
  pointer-events: none;
  background: transparent;
}
.scroll-rail__fill {
  display: block;
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--cyan) 0%, var(--orange) 100%);
  transition: width 0.1s linear;
}

.to-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  z-index: 70;
  width: 46px;
  height: 46px;
  padding: 0;
  display: grid;
  place-items: center;
  font-size: 17px;
  line-height: 1;
  color: var(--cyan);
  background: rgba(16, 26, 56, 0.92);
  border: 1px solid var(--line);
  border-radius: var(--r);
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity 0.24s var(--ease), transform 0.24s var(--ease),
              visibility 0.24s linear, border-color 0.18s var(--ease), color 0.18s var(--ease);
}
.to-top[data-visible] {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}
.to-top:hover { color: var(--orange); border-color: var(--orange); }

@media (max-width: 640px) {
  .to-top { right: 14px; bottom: 14px; width: 42px; height: 42px; }
}

/* ==========================================================================
   显现动画（脚本开启后才生效，无 JS 时内容始终可见）
   ========================================================================== */
[data-js="on"] [data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.42s var(--ease), transform 0.42s var(--ease);
}
[data-js="on"] [data-reveal][data-shown] {
  opacity: 1;
  transform: none;
}

/* ==========================================================================
   降低动态效果
   ========================================================================== */
@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;
  }
  [data-js="on"] [data-reveal] {
    opacity: 1 !important;
    transform: none !important;
    transition: none !important;
  }
  .media-frame__scan { animation: none; }
}