/* =========================================================
   CQ电玩会馆 — /assets/site.css
   共享外壳：reset / 变量 / 中英混排 / 页头 / 页脚 / 基础组件
   ========================================================= */

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

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

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

ul, ol { list-style: none; }

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

button, input, select, textarea {
  font: inherit;
  color: inherit;
}

button {
  background: none;
  border: 0;
  cursor: pointer;
}

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

table { border-collapse: collapse; }

[hidden] { display: none !important; }

/* ---------- 2. 变量 ---------- */
:root {
  --bg: #140B26;
  --tier: #1E1236;
  --cy: #2BE3E0;
  --mg: #FF2E88;
  --hi: #E9FF5A;
  --text: #EAF0FF;
  --muted: #8E9BC7;
  --ok: #5AE7A0;
  --table: #0E2B33;
  --shadow: #7A1440;

  --line: rgba(142, 155, 199, .22);
  --line-cy: rgba(43, 227, 224, .30);
  --line-mg: rgba(255, 46, 136, .30);

  --font-display: "Archivo Black", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-body: Inter, "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  --font-serif: "Noto Serif SC", "Source Han Serif SC", "Songti SC", Georgia, serif;
  --font-mono: "JetBrains Mono", "IBM Plex Mono", ui-monospace, SFMono-Regular, Consolas, "Liberation Mono", monospace;

  --fs-132: clamp(46px, 8.2vw, 132px);
  --fs-88: clamp(38px, 6vw, 88px);
  --fs-56: clamp(30px, 4.2vw, 56px);
  --fs-34: clamp(23px, 2.7vw, 34px);
  --fs-24: clamp(19px, 1.7vw, 24px);
  --fs-17: 17px;
  --fs-14: 14px;
  --fs-13: 13px;

  --shell: 1260px;
  --gutter: clamp(18px, 4vw, 44px);
  --header-h: 92px;
  --ease: cubic-bezier(.22, .61, .36, 1);
}

/* ---------- 3. 基础排版与背景 ---------- */
body {
  min-height: 100vh;
  background-color: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: var(--fs-17);
  line-height: 1.75;
  letter-spacing: .01em;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* 精密网格底 */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image:
    linear-gradient(to right, rgba(43, 227, 224, .05) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(43, 227, 224, .05) 1px, transparent 1px);
  background-size: 74px 74px;
  background-position: center top;
}

/* 缓慢漂移的扫描线 */
body::after {
  content: "";
  position: fixed;
  left: 0;
  right: 0;
  top: -120px;
  bottom: -120px;
  z-index: 0;
  pointer-events: none;
  background: repeating-linear-gradient(
    to bottom,
    rgba(234, 240, 255, .03) 0 1px,
    transparent 1px 5px
  );
  animation: scan-drift 40s linear infinite;
}

@keyframes scan-drift {
  from { transform: translateY(0); }
  to { transform: translateY(-80px); }
}

main {
  position: relative;
  z-index: 1;
  display: block;
}

.site-header,
.site-footer {
  position: relative;
  z-index: 2;
}

h1, h2, h3, h4 {
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -.01em;
}

p { word-break: break-word; }

:focus-visible {
  outline: 2px solid var(--hi);
  outline-offset: 3px;
}

/* ---------- 4. 通用容器与工具类 ---------- */
.shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.visually-hidden {
  position: absolute !important;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
}

.skip-link {
  position: absolute;
  left: var(--gutter);
  top: -120px;
  z-index: 200;
  padding: 12px 20px;
  background: var(--hi);
  color: #1b1700;
  font-family: var(--font-mono);
  font-size: var(--fs-13);
  letter-spacing: .08em;
  transition: top .18s var(--ease);
}

.skip-link:focus {
  top: 10px;
}

.mono {
  font-family: var(--font-mono);
  font-size: var(--fs-13);
  letter-spacing: .06em;
  padding: 2px 6px;
  background: rgba(43, 227, 224, .10);
  color: var(--cy);
}

.mark {
  background: var(--hi);
  color: #1b1700;
  padding: 0 4px;
}

.eyebrow {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--mg);
}

.lede {
  font-family: var(--font-serif);
  font-size: var(--fs-24);
  line-height: 1.55;
  color: var(--muted);
  max-width: 56ch;
}

.glow {
  text-shadow: 0 0 24px rgba(43, 227, 224, .35), 0 0 2px rgba(43, 227, 224, .85);
}

.rule {
  height: 1px;
  border: 0;
  background: var(--line);
  margin-block: clamp(24px, 3vw, 44px);
}

/* ---------- 5. 页头 ---------- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 60;
  background: transparent;
  border-bottom: 1px solid transparent;
  transition:
    background-color .3s var(--ease),
    border-color .3s var(--ease),
    box-shadow .3s var(--ease);
}

.site-header.is-solid {
  background: rgba(20, 11, 38, .94);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  border-bottom-color: var(--line-cy);
  box-shadow: 0 22px 44px -34px rgba(122, 20, 64, 1);
}

.header-shell {
  display: flex;
  align-items: center;
  gap: clamp(14px, 2.4vw, 38px);
  min-height: var(--header-h);
  padding-block: 14px;
  transition: min-height .3s var(--ease), padding-block .3s var(--ease);
}

.site-header.is-solid .header-shell {
  min-height: 66px;
  padding-block: 8px;
}

/* 品牌署名 */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  flex: none;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  flex: none;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .06em;
  color: var(--cy);
  border: 1px solid var(--line-cy);
  background: linear-gradient(140deg, rgba(43, 227, 224, .16), rgba(255, 46, 136, .16));
  box-shadow:
    0 0 22px -8px rgba(43, 227, 224, .9),
    inset 0 0 12px -6px rgba(255, 46, 136, .9);
}

.brand-text {
  display: flex;
  flex-direction: column;
  gap: 1px;
  min-width: 0;
}

.brand-name {
  font-family: var(--font-display);
  font-size: 18px;
  line-height: 1.15;
  letter-spacing: .01em;
  color: var(--text);
}

.brand-sub {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--muted);
}

/* 导航 */
.site-nav {
  flex: 1 1 auto;
  display: flex;
  justify-content: center;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: clamp(4px, 1.4vw, 22px);
}

.nav-link {
  position: relative;
  display: inline-block;
  padding: 7px 6px;
  font-size: 15px;
  line-height: 1.3;
  color: var(--muted);
  white-space: nowrap;
  transition: color .16s var(--ease);
}

.nav-link::after {
  content: "";
  position: absolute;
  left: 6px;
  right: 6px;
  bottom: 2px;
  height: 1px;
  background: var(--cy);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform .22s var(--ease), background-color .16s var(--ease);
}

.nav-link:hover { color: var(--text); }
.nav-link:hover::after,
.nav-link:focus-visible::after { transform: scaleX(1); }

.nav-link[aria-current="page"] {
  color: var(--hi);
}

.nav-link[aria-current="page"]::after {
  transform: scaleX(1);
  background: var(--mg);
  box-shadow: 0 0 12px rgba(255, 46, 136, .85);
}

/* 右侧操作区 */
.header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: none;
}

.help-entry {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 9px 16px;
  border: 1px solid var(--line-cy);
  color: var(--cy);
  font-size: var(--fs-14);
  line-height: 1.2;
  white-space: nowrap;
  transition:
    background-color .18s var(--ease),
    color .18s var(--ease),
    box-shadow .18s var(--ease);
}

.help-entry-key {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .14em;
  padding: 2px 6px;
  background: rgba(43, 227, 224, .14);
  transition: background-color .18s var(--ease), color .18s var(--ease);
}

.help-entry:hover,
.help-entry:focus-visible {
  background: var(--cy);
  color: #04161a;
  box-shadow: 0 0 26px -6px rgba(43, 227, 224, .9);
}

.help-entry:hover .help-entry-key,
.help-entry:focus-visible .help-entry-key {
  background: rgba(4, 22, 26, .18);
  color: #04161a;
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  padding: 9px 14px;
  border: 1px solid var(--line-mg);
  color: var(--mg);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  line-height: 1.2;
  transition: background-color .18s var(--ease);
}

.nav-toggle:hover,
.nav-toggle:focus-visible {
  background: rgba(255, 46, 136, .14);
}

.nav-toggle-bars {
  position: relative;
  display: block;
  width: 18px;
  height: 12px;
  flex: none;
}

.nav-toggle-bars::before,
.nav-toggle-bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 100%;
  height: 1px;
  background: currentColor;
  transition: transform .2s var(--ease);
}

.nav-toggle-bars::before { top: 1px; }
.nav-toggle-bars::after { bottom: 1px; }

.nav-toggle[aria-expanded="true"] .nav-toggle-bars::before {
  transform: translateY(5px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bars::after {
  transform: translateY(-5px) rotate(-45deg);
}

/* 滚动进度线 */
.header-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  transform: scaleX(0);
  transform-origin: left center;
  background: linear-gradient(90deg, var(--cy), var(--hi) 55%, var(--mg));
  box-shadow: 0 0 14px rgba(43, 227, 224, .7);
  pointer-events: none;
  will-change: transform;
}

/* ---------- 6. 页脚 ---------- */
.site-footer {
  margin-top: clamp(72px, 10vw, 140px);
  padding-block: clamp(38px, 4.6vw, 62px) clamp(24px, 3vw, 36px);
  background: linear-gradient(180deg, rgba(30, 18, 54, .88) 0%, rgba(11, 7, 24, .98) 100%);
  border-top: 1px solid var(--line-cy);
}

.site-footer::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  width: min(220px, 40%);
  height: 2px;
  background: linear-gradient(90deg, var(--mg), var(--cy));
  box-shadow: 0 0 18px rgba(255, 46, 136, .6);
}

.footer-prompt {
  display: flex;
  align-items: center;
  gap: 14px;
  font-family: var(--font-serif);
  font-size: var(--fs-24);
  line-height: 1.5;
  color: var(--hi);
  padding-bottom: clamp(18px, 2.4vw, 28px);
  border-bottom: 1px dashed rgba(233, 255, 90, .26);
}

.footer-prompt::before {
  content: "";
  flex: none;
  width: 10px;
  height: 10px;
  background: var(--mg);
  box-shadow: 0 0 16px rgba(255, 46, 136, .9);
}

.footer-band {
  display: grid;
  grid-template-columns: minmax(200px, .9fr) minmax(200px, 1fr) minmax(240px, 1.15fr);
  gap: clamp(22px, 3.4vw, 54px);
  padding-top: clamp(24px, 3.2vw, 40px);
}

.footer-col { min-width: 0; }

.footer-cap {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--cy);
  padding-bottom: 12px;
  margin-bottom: 14px;
  border-bottom: 1px solid rgba(43, 227, 224, .16);
}

.footer-brand {
  font-family: var(--font-display);
  font-size: var(--fs-24);
  line-height: 1.2;
  letter-spacing: .01em;
  color: var(--text);
}

.footer-legal-cn {
  margin-top: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--muted);
}

.footer-note {
  margin-top: 12px;
  max-width: 36ch;
  font-size: var(--fs-14);
  line-height: 1.8;
  color: var(--muted);
}

.footer-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-list--contact li {
  display: flex;
  align-items: baseline;
  gap: 10px;
  font-size: var(--fs-14);
  line-height: 1.7;
  color: var(--text);
  word-break: break-word;
}

.footer-key {
  flex: none;
  min-width: 44px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--mg);
}

.footer-link {
  display: inline-block;
  padding-bottom: 2px;
  font-size: var(--fs-14);
  color: var(--text);
  background-image: linear-gradient(var(--cy), var(--cy));
  background-repeat: no-repeat;
  background-position: 0 100%;
  background-size: 0% 1px;
  transition: background-size .22s var(--ease), color .18s var(--ease);
}

.footer-link:hover,
.footer-link:focus-visible {
  color: var(--cy);
  background-size: 100% 1px;
}

.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 16px;
}

.tag {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .14em;
  padding: 4px 8px;
  color: var(--cy);
  background: rgba(43, 227, 224, .09);
  border: 1px solid rgba(43, 227, 224, .22);
}

.footer-base {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  margin-top: clamp(26px, 3.4vw, 44px);
  padding-top: clamp(16px, 2vw, 22px);
  border-top: 1px solid rgba(142, 155, 199, .16);
}

.footer-copy {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--muted);
}

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
}

/* ---------- 7. 章节节奏 ---------- */
.section {
  position: relative;
  padding-block: clamp(48px, 6.4vw, 104px);
}

.section--tight {
  padding-block: clamp(32px, 4vw, 60px);
}

.sec-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: clamp(12px, 1.8vw, 26px);
  margin-bottom: clamp(22px, 3vw, 40px);
}

.sec-label {
  font-family: var(--font-serif);
  font-size: var(--fs-24);
  line-height: 1.3;
  color: var(--muted);
  white-space: nowrap;
}

.sec-title {
  font-family: var(--font-display);
  font-size: var(--fs-56);
  line-height: 1.02;
  letter-spacing: -.02em;
  color: var(--text);
}

.section-rule {
  flex: 1 1 auto;
  min-width: 40px;
  height: 1px;
  align-self: center;
  background: linear-gradient(90deg, var(--line-cy), transparent);
}

/* ---------- 8. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 12px 22px;
  font-family: var(--font-body);
  font-size: 15px;
  line-height: 1.2;
  letter-spacing: .02em;
  border: 1px solid transparent;
  transition:
    background-color .18s var(--ease),
    color .18s var(--ease),
    border-color .18s var(--ease),
    box-shadow .18s var(--ease),
    transform .18s var(--ease);
}

.btn--cyan {
  background: var(--cy);
  border-color: var(--cy);
  color: #04161a;
}

.btn--cyan:hover,
.btn--cyan:focus-visible {
  box-shadow: 0 0 30px -6px rgba(43, 227, 224, .95);
  transform: translateY(-1px);
}

.btn--magenta {
  background: transparent;
  border-color: var(--mg);
  color: var(--mg);
}

.btn--magenta:hover,
.btn--magenta:focus-visible {
  background: var(--mg);
  color: #180410;
  box-shadow: 0 0 30px -8px rgba(255, 46, 136, .95);
}

.btn--ghost {
  background: transparent;
  border-color: var(--line);
  color: var(--text);
}

.btn--ghost:hover,
.btn--ghost:focus-visible {
  border-color: var(--cy);
  color: var(--cy);
}

.btn--mark {
  background: var(--hi);
  border-color: var(--hi);
  color: #1c1a00;
}

.btn--mark:hover,
.btn--mark:focus-visible {
  box-shadow: 0 0 30px -8px rgba(233, 255, 90, .9);
}

/* ---------- 9. 面包屑 ---------- */
.crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--muted);
}

.crumbs li {
  display: flex;
  align-items: center;
  gap: 10px;
}

.crumbs li + li::before {
  content: "/";
  color: rgba(142, 155, 199, .5);
}

.crumbs a {
  color: var(--muted);
  transition: color .16s var(--ease);
}

.crumbs a:hover { color: var(--cy); }

.crumbs [aria-current="page"] { color: var(--hi); }

/* ---------- 10. 正文容器 ---------- */
.prose {
  max-width: 72ch;
  font-size: var(--fs-17);
  line-height: 1.85;
  color: var(--text);
}

.prose > * + * { margin-top: 1.15em; }

.prose h2 {
  font-family: var(--font-display);
  font-size: var(--fs-34);
  line-height: 1.2;
  letter-spacing: -.01em;
  margin-top: 2.2em;
}

.prose h3 {
  font-family: var(--font-serif);
  font-size: var(--fs-24);
  line-height: 1.35;
  color: var(--hi);
  margin-top: 1.8em;
}

.prose a {
  color: var(--cy);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

.prose a:hover { color: var(--hi); }

.prose ul,
.prose ol { padding-left: 1.4em; }

.prose ul li {
  position: relative;
  list-style: none;
}

.prose ul li::before {
  content: "";
  position: absolute;
  left: -1.1em;
  top: .8em;
  width: 7px;
  height: 1px;
  background: var(--mg);
}

.prose ol { list-style: decimal; }

.prose ol li::marker {
  font-family: var(--font-mono);
  color: var(--mg);
}

.prose blockquote {
  padding-left: 1.2em;
  border-left: 2px solid var(--cy);
  font-family: var(--font-serif);
  font-size: var(--fs-24);
  line-height: 1.5;
  color: var(--muted);
}

.prose code {
  font-family: var(--font-mono);
  font-size: .9em;
  padding: .1em .4em;
  background: rgba(43, 227, 224, .12);
  color: var(--cy);
}

/* ---------- 11. 栅格 ---------- */
.grid {
  display: grid;
  gap: clamp(18px, 2.4vw, 32px);
}

.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

.grid--editorial {
  grid-template-columns: minmax(0, 2fr) minmax(0, 1fr);
}

/* ---------- 12. 索引卡 ---------- */
.card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: clamp(18px, 2vw, 26px);
  background: rgba(30, 18, 54, .72);
  border: 1px solid var(--line);
  transition:
    border-color .2s var(--ease),
    background-color .2s var(--ease),
    box-shadow .2s var(--ease),
    transform .2s var(--ease);
}

.card:hover {
  border-color: var(--cy);
  background: rgba(30, 18, 54, .94);
  box-shadow:
    0 0 0 1px rgba(43, 227, 224, .18),
    0 26px 44px -34px rgba(43, 227, 224, .7);
}

.card-num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--mg);
}

.card-title {
  font-family: var(--font-display);
  font-size: var(--fs-24);
  line-height: 1.25;
  color: var(--text);
}

.card-text {
  font-size: var(--fs-14);
  line-height: 1.8;
  color: var(--muted);
}

.card-link {
  margin-top: auto;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--cy);
}

.card-link::after {
  content: "→";
  transition: transform .2s var(--ease);
}

.card:hover .card-link::after { transform: translateX(4px); }

.card--drop-1 { margin-top: 14px; }
.card--drop-2 { margin-top: 28px; }

/* ---------- 13. 时间线 ---------- */
.timeline {
  position: relative;
  display: flex;
  flex-direction: column;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 0;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(180deg, var(--cy), var(--mg));
}

.timeline-item {
  position: relative;
  padding: 0 0 clamp(22px, 3vw, 34px) clamp(24px, 3vw, 40px);
}

.timeline-item:last-child { padding-bottom: 0; }

.timeline-item::before {
  content: "";
  position: absolute;
  left: -3px;
  top: 9px;
  width: 7px;
  height: 7px;
  background: var(--mg);
  box-shadow: 0 0 12px rgba(255, 46, 136, .9);
}

/* ---------- 14. 坐标对照表 ---------- */
.coords {
  width: 100%;
  font-size: var(--fs-14);
}

.coords caption {
  padding-bottom: 12px;
  text-align: left;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--muted);
}

.coords th,
.coords td {
  padding: 14px 16px;
  text-align: left;
  vertical-align: top;
  border-bottom: 1px solid rgba(142, 155, 199, .16);
}

.coords thead th {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--cy);
  background: rgba(14, 43, 51, .72);
  border-bottom-color: var(--line-cy);
}

.coords tbody tr:nth-child(even) { background: rgba(30, 18, 54, .5); }

.coords tbody tr:hover { background: rgba(43, 227, 224, .06); }

.coords .code {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--hi);
  white-space: nowrap;
}

/* ---------- 15. 折叠问答 ---------- */
.accordion { border-top: 1px solid var(--line); }

.accordion-item { border-bottom: 1px solid var(--line); }

.accordion-head {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  width: 100%;
  padding: 18px 4px;
  text-align: left;
  font-size: var(--fs-17);
  line-height: 1.6;
  color: var(--text);
  transition: color .16s var(--ease);
}

.accordion-head:hover { color: var(--cy); }

.accordion-sign {
  position: relative;
  flex: none;
  width: 16px;
  height: 16px;
  margin-top: 7px;
  border: 1px solid var(--line-cy);
}

.accordion-sign::before,
.accordion-sign::after {
  content: "";
  position: absolute;
  background: var(--cy);
}

.accordion-sign::before {
  left: 3px;
  right: 3px;
  top: 7px;
  height: 1px;
}

.accordion-sign::after {
  top: 3px;
  bottom: 3px;
  left: 7px;
  width: 1px;
  transition: transform .2s var(--ease);
}

.accordion-head[aria-expanded="true"] .accordion-sign::after {
  transform: scaleY(0);
}

.accordion-panel {
  padding: 0 4px 20px 34px;
  font-size: var(--fs-14);
  line-height: 1.85;
  color: var(--muted);
}

/* ---------- 16. 检索条 ---------- */
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  padding: 14px 16px;
  background: rgba(14, 43, 51, .6);
  border: 1px solid var(--line-cy);
}

.filter-input {
  flex: 1 1 240px;
  min-width: 0;
  padding: 11px 14px;
  background: rgba(20, 11, 38, .8);
  border: 1px solid var(--line);
  color: var(--text);
  font-size: var(--fs-14);
  transition: border-color .18s var(--ease), box-shadow .18s var(--ease);
}

.filter-input:focus {
  border-color: var(--cy);
  box-shadow: 0 0 0 2px rgba(43, 227, 224, .16);
}

.filter-input::placeholder { color: rgba(142, 155, 199, .75); }

.filter-count {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--hi);
  white-space: nowrap;
}

/* ---------- 17. 图片容器 ---------- */
.frame {
  position: relative;
  display: block;
  overflow: hidden;
  background:
    linear-gradient(135deg, rgba(43, 227, 224, .10), rgba(255, 46, 136, .10)),
    var(--tier);
  border: 1px solid var(--line-cy);
}

.frame img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(1.05) contrast(1.04);
}

.frame::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  z-index: 1;
  width: 22px;
  height: 22px;
  border-top: 1px solid var(--cy);
  border-left: 1px solid var(--cy);
  pointer-events: none;
}

.frame::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: repeating-linear-gradient(
    to bottom,
    rgba(20, 11, 38, .18) 0 1px,
    transparent 1px 4px
  );
  mix-blend-mode: multiply;
}

.frame--16x9 { aspect-ratio: 16 / 9; }
.frame--4x3 { aspect-ratio: 4 / 3; }
.frame--1x1 { aspect-ratio: 1 / 1; }
.frame--wide { aspect-ratio: 21 / 9; }

.frame-cap {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--muted);
}

/* ---------- 18. 返回顶部 ---------- */
.to-top {
  position: fixed;
  right: clamp(14px, 2.4vw, 28px);
  bottom: 28px;
  z-index: 70;
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  background: rgba(20, 11, 38, .92);
  border: 1px solid var(--line-cy);
  color: var(--cy);
  font-family: var(--font-mono);
  font-size: 16px;
  line-height: 1;
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition:
    opacity .22s var(--ease),
    visibility .22s linear,
    transform .22s var(--ease),
    background-color .18s var(--ease),
    color .18s var(--ease);
}

.to-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: none;
}

.to-top:hover,
.to-top:focus-visible {
  background: var(--cy);
  color: #04161a;
}

/* ---------- 19. 平板 ---------- */
@media (max-width: 1080px) {
  .nav-list { gap: 4px; }
  .nav-link { padding: 7px 5px; font-size: 14px; }
  .brand-sub { display: none; }
}

/* ---------- 20. 移动端：页头沉底为悬浮条 ---------- */
@media (max-width: 900px) {
  .site-header,
  .site-header.is-solid {
    top: auto;
    bottom: 12px;
    left: 12px;
    right: 12px;
    background: rgba(20, 11, 38, .96);
    -webkit-backdrop-filter: blur(14px);
    backdrop-filter: blur(14px);
    border: 1px solid var(--line-cy);
    box-shadow:
      0 -14px 44px -24px rgba(122, 20, 64, 1),
      0 0 0 1px rgba(255, 46, 136, .06);
  }

  .header-shell,
  .site-header.is-solid .header-shell {
    min-height: 58px;
    padding: 8px 14px;
    gap: 10px;
  }

  .brand { margin-right: auto; min-width: 0; }
  .brand-mark { width: 34px; height: 34px; font-size: 12px; }
  .brand-name {
    display: block;
    font-size: 15px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
  }
  .brand-sub { display: none; }

  .site-nav {
    position: absolute;
    left: 0;
    right: 0;
    bottom: calc(100% + 10px);
    display: block;
    max-height: 0;
    overflow: hidden;
    visibility: hidden;
    opacity: 0;
    background: rgba(30, 18, 54, .98);
    border: 1px solid var(--line-cy);
    box-shadow: 0 -18px 50px -26px rgba(122, 20, 64, 1);
    overscroll-behavior: contain;
    transition:
      max-height .26s var(--ease),
      opacity .2s var(--ease),
      visibility .26s linear;
  }

  .site-nav[data-open] {
    max-height: min(70vh, 460px);
    overflow-y: auto;
    visibility: visible;
    opacity: 1;
  }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 6px;
  }

  .nav-link {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 14px;
    font-size: 16px;
    border-bottom: 1px solid rgba(142, 155, 199, .14);
  }

  .nav-list li:last-child .nav-link { border-bottom: 0; }

  .nav-link::after { display: none; }

  .nav-link[aria-current="page"] {
    background: rgba(233, 255, 90, .07);
    box-shadow: inset 3px 0 0 var(--mg);
  }

  .nav-toggle { display: inline-flex; }

  .header-progress { display: none; }

  .site-footer { padding-bottom: 104px; }

  .to-top { right: 14px; bottom: 92px; }

  .footer-band { grid-template-columns: 1fr 1fr; }
  .footer-band > .footer-col:first-child { grid-column: 1 / -1; }

  .grid--3,
  .grid--4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid--editorial { grid-template-columns: 1fr; }

  .card--drop-1,
  .card--drop-2 { margin-top: 0; }
}

/* ---------- 21. 小屏 ---------- */
@media (max-width: 560px) {
  body { font-size: 16px; }

  .brand-name { font-size: 14px; }
  .brand-mark { width: 30px; height: 30px; font-size: 11px; }
  .help-entry { padding: 8px 10px; font-size: 13px; gap: 0; }
  .help-entry-key { display: none; }
  .nav-toggle { padding: 8px 10px; }
  .nav-toggle-text { display: none; }

  .footer-band { grid-template-columns: 1fr; }
  .footer-band > .footer-col:first-child { grid-column: auto; }
  .footer-prompt { font-size: 19px; }
  .footer-prompt::before { width: 8px; height: 8px; }
  .footer-base { flex-direction: column; align-items: flex-start; }

  .grid--2,
  .grid--3,
  .grid--4 { grid-template-columns: 1fr; }

  .sec-head { flex-direction: column; align-items: flex-start; gap: 8px; }
  .section-rule { width: 100%; }

  .coords th,
  .coords td { padding: 11px 10px; font-size: 13px; }
}

/* ---------- 22. 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  body::after { animation: none; }

  *,
  *::before,
  *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }
}