/* =========================================================
   银河会馆 · 共享样式 /assets/site.css
   框架式页头 + 深空底色 + 刻度与光带衔接
   ========================================================= */

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

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 6.5rem;
}

body {
  margin: 0;
  background-color: #060a17;
  background-image:
    radial-gradient(120% 70% at 78% -8%, rgba(139, 92, 246, 0.20), transparent 60%),
    radial-gradient(80% 55% at 6% 2%, rgba(34, 211, 238, 0.12), transparent 62%),
    radial-gradient(70% 50% at 48% 106%, rgba(244, 114, 182, 0.10), transparent 66%);
  background-repeat: no-repeat;
  background-attachment: fixed;
  color: var(--ink-star);
  font-family: var(--font-body);
  font-size: var(--fs-body);
  line-height: 1.85;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5, h6 {
  margin: 0 0 0.6em;
  font-family: var(--font-head);
  font-weight: 700;
  letter-spacing: 0.02em;
  line-height: 1.24;
  color: var(--ink-star);
}

h1 { font-size: var(--fs-h1); }
h2 { font-size: var(--fs-h2); }
h3 { font-size: 1.1875rem; }
h4 { font-size: 1.0625rem; }

p { margin: 0 0 1.2em; }
p:last-child { margin-bottom: 0; }

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

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

a { color: inherit; }

button { font: inherit; color: inherit; }

table { border-collapse: collapse; width: 100%; }

hr { border: 0; border-top: 1px solid var(--line); margin: 2rem 0; }

/* ---------- 2. 设计变量 ---------- */
:root {
  --ink-void: #060A17;
  --ink-orbit: #0D142B;
  --ink-star: #EEF3FB;
  --ink-silver: #B9C2D4;
  --line: #26304C;
  --violet: #8B5CF6;
  --pink: #F472B6;
  --cyan: #22D3EE;
  --amber: #F5B942;

  --font-head: 'HarmonyOS Sans SC', 'Source Han Sans SC', 'Noto Sans SC', system-ui, -apple-system, 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-body: 'Source Han Serif SC', 'Noto Serif SC', 'Songti SC', Georgia, serif;
  --font-mono: 'JetBrains Mono', 'IBM Plex Mono', 'SFMono-Regular', ui-monospace, Consolas, monospace;

  --fs-h1: clamp(2.4rem, 5vw, 4.2rem);
  --fs-h2: clamp(1.6rem, 3vw, 2.4rem);
  --fs-body: 1.0625rem;
  --fs-cap: 0.8125rem;

  --gutter: clamp(1.25rem, 4vw, 3rem);
  --radius: 2px;
  --ease: 180ms ease;
}

/* ---------- 3. 可访问性基础 ---------- */
:focus-visible {
  outline: 1px solid var(--cyan);
  outline-offset: 3px;
  border-radius: 1px;
}

.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;
  left: 1rem;
  top: -6rem;
  z-index: 300;
  padding: 0.65rem 1.1rem;
  background: var(--violet);
  color: #04070F;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  text-decoration: none;
  border-radius: var(--radius);
  transition: top var(--ease);
}

.skip-link:focus {
  top: 0.75rem;
}

#main-content { display: block; }
#main-content:focus { outline: none; }

/* ---------- 4. 布局骨架 ---------- */
.shell {
  width: min(1240px, calc(100% - var(--gutter) * 2));
  margin-inline: auto;
}

.band-section {
  position: relative;
  padding-block: clamp(3rem, 7vw, 6rem);
}

.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  column-gap: clamp(1rem, 2vw, 1.75rem);
  row-gap: clamp(1.5rem, 3vw, 2.5rem);
}

.col-main  { grid-column: 1 / span 8; }
.col-rail  { grid-column: 9 / span 4; }
.col-wide  { grid-column: 1 / span 12; }
.col-shift { grid-column: 2 / span 7; }

/* 章节之间的渐隐光带与三点刻度 */
.beam-divider {
  height: 1px;
  margin-block: clamp(2.5rem, 5vw, 4rem);
  background-image:
    radial-gradient(circle, var(--cyan) 1px, transparent 1.7px),
    radial-gradient(circle, var(--ink-silver) 1px, transparent 1.7px),
    radial-gradient(circle, var(--pink) 1px, transparent 1.7px),
    linear-gradient(90deg, transparent, rgba(139, 92, 246, 0.55) 12%, rgba(38, 48, 76, 0.95) 45%, rgba(38, 48, 76, 0.95) 55%, rgba(34, 211, 238, 0.55) 88%, transparent);
  background-repeat: no-repeat;
  background-size: 7px 7px, 7px 7px, 7px 7px, 100% 1px;
  background-position: 12% 50%, 50% 50%, 88% 50%, 0 50%;
}

.rail-index {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  margin-bottom: 1rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.22em;
  color: var(--violet);
  text-transform: uppercase;
}

.rail-index::after {
  content: '';
  flex: 1 1 auto;
  height: 1px;
  background: linear-gradient(90deg, rgba(139, 92, 246, 0.8), transparent);
}

/* ---------- 5. 中文正文容器 ---------- */
.prose {
  max-width: 38rem;
  line-height: 1.85;
  color: var(--ink-silver);
}

.prose p { margin: 0 0 1.5em; }

.prose h2,
.prose h3 {
  color: var(--ink-star);
  margin-top: 1.8em;
}

.prose h2:first-child,
.prose h3:first-child { margin-top: 0; }

.prose strong { color: var(--ink-star); font-weight: 700; }

.prose a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(34, 211, 238, 0.35);
  transition: border-color var(--ease);
}

.prose a:hover { border-bottom-color: var(--cyan); }

.prose ul,
.prose ol { margin: 0 0 1.5em; padding-left: 1.2em; }

.prose li {
  list-style: disc;
  margin-bottom: 0.5em;
}

/* ---------- 6. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.7rem 1.35rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: transparent;
  color: var(--ink-star);
  font-family: var(--font-head);
  font-size: 0.9375rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-decoration: none;
  cursor: pointer;
  transition: color var(--ease), border-color var(--ease), background-color var(--ease);
}

.btn::after {
  content: '→';
  font-family: var(--font-mono);
  font-size: 0.85em;
  transition: transform var(--ease);
}

.btn:hover { border-color: var(--cyan); color: var(--cyan); }
.btn:hover::after { transform: translateX(3px); }

.btn--primary {
  background: linear-gradient(120deg, rgba(139, 92, 246, 0.92), rgba(34, 211, 238, 0.85));
  border-color: transparent;
  color: #04070F;
}

.btn--primary:hover {
  color: #04070F;
  border-color: transparent;
  filter: brightness(1.08);
}

.btn--quiet {
  border-color: transparent;
  padding-inline: 0.4rem;
  color: var(--ink-silver);
}

.btn--quiet:hover { color: var(--cyan); }

/* ---------- 7. 面包屑 ---------- */
.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.4rem 0.6rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  color: var(--ink-silver);
}

.breadcrumbs li + li::before {
  content: '/';
  margin-right: 0.6rem;
  color: var(--line);
}

.breadcrumbs a {
  color: var(--ink-silver);
  text-decoration: none;
  transition: color var(--ease);
}

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

/* ---------- 8. 面板 / 折叠 / 标签 ---------- */
.panel {
  background: var(--ink-orbit);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.panel__head {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: baseline;
  gap: 0.75rem;
  padding: 1rem 1.25rem;
  border-bottom: 1px solid var(--line);
}

.panel__title {
  margin: 0;
  font-family: var(--font-head);
  font-size: 1rem;
  letter-spacing: 0.03em;
}

.panel__body { padding: 1.25rem; }

.fold {
  background: var(--ink-orbit);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.fold + .fold { margin-top: 0.6rem; }

.fold > summary {
  display: flex;
  align-items: center;
  gap: 0.8rem;
  padding: 1rem 1.25rem;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-head);
  font-size: 0.9375rem;
  letter-spacing: 0.02em;
  color: var(--ink-star);
  transition: color var(--ease);
}

.fold > summary::-webkit-details-marker { display: none; }

.fold > summary::before {
  content: '+';
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--cyan);
  line-height: 1;
}

.fold[open] > summary::before { content: '–'; color: var(--pink); }
.fold > summary:hover { color: var(--cyan); }

.fold__body {
  padding: 0 1.25rem 1.15rem;
  font-size: 0.9375rem;
  color: var(--ink-silver);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.26rem 0.55rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.12em;
  color: var(--ink-silver);
  text-transform: uppercase;
}

.tag--violet { color: var(--violet); border-color: rgba(139, 92, 246, 0.5); }
.tag--pink   { color: var(--pink);   border-color: rgba(244, 114, 182, 0.5); }
.tag--cyan   { color: var(--cyan);   border-color: rgba(34, 211, 238, 0.5); }
.tag--amber  { color: var(--amber);  border-color: rgba(245, 185, 66, 0.5); }

.pulse-dot {
  display: inline-block;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--amber);
  animation: pulse 2s ease-out infinite;
}

@keyframes pulse {
  0%   { box-shadow: 0 0 0 0 rgba(245, 185, 66, 0.5); }
  70%  { box-shadow: 0 0 0 7px rgba(245, 185, 66, 0); }
  100% { box-shadow: 0 0 0 0 rgba(245, 185, 66, 0); }
}

/* ---------- 9. 图片容器基础规则 ---------- */
.frame-media {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  aspect-ratio: 16 / 9;
  background-color: var(--ink-orbit);
  background-image:
    radial-gradient(120% 120% at 28% 18%, rgba(139, 92, 246, 0.24), transparent 62%),
    radial-gradient(90% 90% at 82% 88%, rgba(34, 211, 238, 0.14), transparent 66%);
}

.frame-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.frame-media::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, transparent 52%, rgba(6, 10, 23, 0.78));
  pointer-events: none;
}

.frame-media__caption {
  position: absolute;
  left: 1rem;
  right: 1rem;
  bottom: 0.85rem;
  z-index: 1;
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.06em;
  color: var(--ink-silver);
}

.frame-media--deep { aspect-ratio: 21 / 9; }
.frame-media--portrait { aspect-ratio: 3 / 4; }

.frame-media--empty::before {
  content: attr(data-label);
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  padding: 1rem;
  text-align: center;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.1em;
  color: var(--ink-silver);
  opacity: 0.65;
}

/* ---------- 10. 滚动显现协议 ---------- */
[data-reveal] {
  transition: opacity 0.5s ease, transform 0.5s ease;
}

[data-reveal].is-pending {
  opacity: 0;
  transform: translateY(10px);
}

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

/* =========================================================
   11. 页头 —— 导航作为页面边框
   ========================================================= */
.frame-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: linear-gradient(180deg, rgba(6, 10, 23, 0.99), rgba(9, 14, 30, 0.94));
  border-bottom: 1px solid var(--line);
}

.frame-header::before {
  content: '';
  position: absolute;
  inset: 0 0 auto 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(139, 92, 246, 0.7) 18%, rgba(34, 211, 238, 0.75) 50%, rgba(244, 114, 182, 0.7) 82%, transparent);
  opacity: 0.75;
}

.progress-beam {
  position: absolute;
  inset: 0 0 auto 0;
  height: 2px;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--violet), var(--cyan));
  box-shadow: 0 0 10px rgba(34, 211, 238, 0.5);
  z-index: 3;
}

.frame-ruler {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 7px;
  pointer-events: none;
  background-image: repeating-linear-gradient(90deg, var(--line) 0 1px, transparent 1px 16px);
  background-size: 16px 7px;
  -webkit-mask-image: linear-gradient(90deg, transparent, #000 6%, #000 94%, transparent);
  mask-image: linear-gradient(90deg, transparent, #000 6%, #000 94%, transparent);
}

.frame-header__inner {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: clamp(1rem, 2.5vw, 2.5rem);
  min-height: 4.75rem;
  padding-block: 0.8rem;
}

/* 品牌 */
.frame-brand {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  text-decoration: none;
  color: inherit;
}

.frame-brand__mark {
  position: relative;
  flex: 0 0 auto;
  width: 34px;
  height: 34px;
  border: 1px solid var(--line);
  border-radius: 50%;
}

.frame-brand__mark::before {
  content: '';
  position: absolute;
  inset: 6px;
  border-radius: 50%;
  background: radial-gradient(circle at 34% 30%, var(--cyan), var(--violet) 58%, transparent 74%);
  box-shadow: 0 0 12px rgba(34, 211, 238, 0.45);
}

.frame-brand__mark::after {
  content: '';
  position: absolute;
  inset: -6px;
  border-radius: 50%;
  border: 1px solid rgba(139, 92, 246, 0.48);
  transform: rotate(-24deg) scaleY(0.34);
}

.frame-brand__text {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
  line-height: 1.2;
}

.frame-brand__name {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 1.0625rem;
  letter-spacing: 0.07em;
  color: var(--ink-star);
}

.frame-brand__meta {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.frame-brand__sub {
  font-family: var(--font-mono);
  font-size: 0.625rem;
  letter-spacing: 0.05em;
  color: var(--ink-silver);
}

.frame-brand__tagline {
  display: none;
  font-family: var(--font-mono);
  font-size: 0.625rem;
  letter-spacing: 0.14em;
  color: var(--violet);
}

.frame-brand__tagline::before {
  content: '·';
  margin-right: 0.5rem;
  color: var(--line);
}

/* 主导航 */
.frame-nav { display: flex; justify-content: center; }

.frame-nav__list {
  display: flex;
  align-items: center;
  gap: clamp(0.35rem, 1.3vw, 1.35rem);
}

.frame-nav__item { position: relative; }

.frame-nav__link {
  position: relative;
  display: block;
  padding: 0.55rem 0.3rem;
  color: var(--ink-silver);
  font-family: var(--font-head);
  font-size: 0.9375rem;
  letter-spacing: 0.03em;
  text-decoration: none;
  transition: color var(--ease);
}

.frame-nav__link::before {
  content: '';
  position: absolute;
  left: 50%;
  top: 0.2rem;
  width: 3px;
  height: 3px;
  border-radius: 50%;
  background: var(--line);
  transform: translateX(-50%);
  transition: background var(--ease);
}

.frame-nav__link::after {
  content: '';
  position: absolute;
  left: 0;
  right: 0;
  bottom: -0.35rem;
  height: 1px;
  background: var(--cyan);
  transform: scaleX(0);
  transform-origin: 50% 50%;
  transition: transform var(--ease);
}

.frame-nav__link:hover { color: var(--ink-star); }
.frame-nav__link:hover::after { transform: scaleX(1); }

.frame-nav__link[aria-current="page"] { color: var(--ink-star); }

.frame-nav__link[aria-current="page"]::before {
  background: var(--amber);
  box-shadow: 0 0 6px rgba(245, 185, 66, 0.7);
}

.frame-nav__link[aria-current="page"]::after {
  transform: scaleX(1);
  box-shadow: 0 0 8px rgba(34, 211, 238, 0.6);
}

/* 右上角动作区 */
.frame-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.frame-utility { position: relative; }

.frame-utility__trigger {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 0.8rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(13, 20, 43, 0.6);
  color: var(--ink-silver);
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.1em;
  cursor: pointer;
  list-style: none;
  transition: color var(--ease), border-color var(--ease);
}

.frame-utility__trigger::-webkit-details-marker { display: none; }

.frame-utility__trigger::before {
  content: '';
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--amber);
  box-shadow: 0 0 6px rgba(245, 185, 66, 0.7);
}

.frame-utility__trigger:hover,
.frame-utility[open] .frame-utility__trigger {
  color: var(--ink-star);
  border-color: rgba(34, 211, 238, 0.6);
}

.frame-utility__panel {
  position: absolute;
  right: 0;
  top: calc(100% + 0.7rem);
  z-index: 5;
  width: min(272px, 82vw);
  display: grid;
  gap: 0.6rem;
  padding: 1rem 1.1rem;
  background: var(--ink-orbit);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 0 18px 42px rgba(0, 0, 0, 0.6);
}

.frame-utility__note {
  margin: 0;
  font-size: 0.75rem;
  line-height: 1.7;
  color: var(--ink-silver);
}

.frame-utility__link {
  padding-bottom: 0.25rem;
  border-bottom: 1px solid transparent;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.05em;
  color: var(--ink-silver);
  text-decoration: none;
  transition: color var(--ease), border-color var(--ease);
}

.frame-utility__link:hover {
  color: var(--cyan);
  border-bottom-color: rgba(34, 211, 238, 0.5);
}

/* 移动端开关 */
.frame-toggle {
  display: none;
  width: 42px;
  height: 42px;
  place-items: center;
  padding: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(13, 20, 43, 0.6);
  cursor: pointer;
  transition: border-color var(--ease);
}

.frame-toggle:hover { border-color: rgba(34, 211, 238, 0.6); }

.frame-toggle__bar {
  position: relative;
  display: block;
  width: 16px;
  height: 1px;
  background: var(--ink-silver);
  transition: background var(--ease);
}

.frame-toggle__bar::before,
.frame-toggle__bar::after {
  content: '';
  position: absolute;
  left: 0;
  width: 16px;
  height: 1px;
  background: inherit;
  transition: transform var(--ease);
}

.frame-toggle__bar::before { top: -5px; }
.frame-toggle__bar::after  { top: 5px; }

.frame-header[data-open] .frame-toggle__bar { background: var(--cyan); }
.frame-header[data-open] .frame-toggle__bar::before { transform: translateY(5px) rotate(45deg); }
.frame-header[data-open] .frame-toggle__bar::after  { transform: translateY(-5px) rotate(-45deg); }

.nav-scrim {
  position: fixed;
  inset: 0;
  z-index: 90;
  border: 0;
  padding: 0;
  background: rgba(3, 6, 14, 0.74);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.24s ease;
}

.frame-header[data-open] .nav-scrim {
  opacity: 1;
  pointer-events: auto;
}

/* =========================================================
   12. 页脚
   ========================================================= */
.galaxy-footer {
  position: relative;
  margin-top: clamp(4rem, 9vw, 8rem);
  padding: clamp(2.5rem, 5vw, 4rem) 0 1.5rem;
  background: linear-gradient(180deg, var(--ink-void), #04070F 72%);
  border-top: 1px solid var(--line);
  font-size: 0.875rem;
}

.galaxy-footer::before {
  content: '';
  position: absolute;
  top: -1px;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent, rgba(139, 92, 246, 0.75) 20%, rgba(34, 211, 238, 0.8) 50%, rgba(244, 114, 182, 0.75) 80%, transparent);
  opacity: 0.6;
}

.footer-grid {
  display: grid;
  grid-template-columns: minmax(200px, 1.6fr) repeat(3, minmax(120px, 1fr));
  gap: clamp(1.5rem, 4vw, 3rem);
}

.footer-brand__name {
  margin: 0 0 0.6rem;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 1.25rem;
  letter-spacing: 0.07em;
  color: var(--ink-star);
}

.footer-brand__note {
  margin: 0 0 0.9rem;
  max-width: 30ch;
  font-size: 0.8125rem;
  line-height: 1.9;
  color: var(--ink-silver);
}

.footer-brand__domain {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.08em;
  color: var(--violet);
}

.footer-col__title {
  margin: 0 0 1rem;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.2em;
  color: var(--ink-silver);
  text-transform: uppercase;
}

.footer-col__list {
  display: grid;
  gap: 0.55rem;
}

.footer-col__link {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.03em;
  color: var(--ink-silver);
  text-decoration: none;
  transition: color var(--ease);
}

.footer-col__link:hover { color: var(--cyan); }

.footer-base {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-start;
  gap: 0.35rem 2rem;
  margin-top: clamp(2rem, 4vw, 3rem);
  padding-top: 1.25rem;
  border-top: 1px solid var(--line);
}

.footer-base__item {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.02em;
  color: var(--ink-silver);
}

.footer-base__item--wide {
  flex: 1 1 100%;
  max-width: 66ch;
}

.footer-base__item--legal { color: var(--violet); }

.footer-credit {
  margin: 1.5rem auto 0;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.08em;
  color: var(--ink-silver);
}

/* =========================================================
   13. 响应式
   ========================================================= */
@media (min-width: 1180px) {
  .frame-brand__tagline { display: inline-block; }
}

@media (max-width: 1100px) {
  .frame-cta { display: none; }
}

@media (max-width: 960px) {
  .frame-header__inner {
    grid-template-columns: auto auto;
    justify-content: space-between;
  }

  .frame-toggle { display: grid; }

  .frame-nav {
    position: fixed;
    top: 0;
    bottom: 0;
    left: 0;
    z-index: 100;
    width: min(84vw, 330px);
    padding: 5.75rem 1.5rem 2rem;
    overflow-y: auto;
    background: linear-gradient(180deg, var(--ink-orbit), var(--ink-void) 88%);
    border-right: 1px solid var(--line);
    transform: translateX(-102%);
    transition: transform 0.26s ease;
  }

  .frame-nav::before {
    content: '';
    position: absolute;
    top: 4.9rem;
    left: 1.5rem;
    right: 1.5rem;
    height: 6px;
    background-image: repeating-linear-gradient(90deg, var(--line) 0 1px, transparent 1px 12px);
    background-size: 12px 6px;
    -webkit-mask-image: linear-gradient(90deg, #000, transparent);
    mask-image: linear-gradient(90deg, #000, transparent);
  }

  .frame-header[data-open] .frame-nav { transform: translateX(0); }

  .frame-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }

  .frame-nav__link {
    padding: 0.9rem 0.2rem;
    border-bottom: 1px solid rgba(38, 48, 76, 0.7);
    font-size: 1rem;
  }

  .frame-nav__link::before { display: none; }

  .frame-nav__link::after {
    left: 0;
    right: auto;
    bottom: -1px;
    width: 2.5rem;
  }
}

@media (max-width: 900px) {
  .grid-12 { grid-template-columns: repeat(6, minmax(0, 1fr)); }
  .col-main,
  .col-rail,
  .col-shift { grid-column: 1 / -1; }
  .col-wide { grid-column: 1 / -1; }

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

@media (max-width: 640px) {
  body {
    background-attachment: scroll;
    font-size: 1rem;
  }

  .grid-12 { grid-template-columns: 1fr; }

  .footer-grid { grid-template-columns: 1fr; }

  .frame-utility__label { display: none; }

  .frame-utility__trigger { padding: 0.5rem 0.6rem; }

  .footer-base { gap: 0.5rem 1.25rem; }

  .band-section { padding-block: clamp(2.25rem, 9vw, 3.5rem); }
}

/* =========================================================
   14. 动效偏好与打印
   ========================================================= */
@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-reveal],
  [data-reveal].is-pending {
    opacity: 1;
    transform: none;
  }

  .pulse-dot { animation: none; box-shadow: 0 0 0 3px rgba(245, 185, 66, 0.25); }
}

@media print {
  .frame-header,
  .galaxy-footer,
  .nav-scrim,
  .progress-beam { display: none !important; }
  body { background: #fff; color: #000; }
}