/* ===================================================================
   乐鱼主站 · 共享样式表 /assets/site.css
   结构：reset → 变量 → 排版 → 框架外壳（头部）→ 页脚 → 通用组件 → 响应式
   =================================================================== */

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-padding-top: 96px;
}

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

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

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

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

a { color: inherit; }

/* ---------- 2. 变量 ---------- */
:root {
  /* 色彩 */
  --night: #0B1A2E;
  --ink: #111A24;
  --paper: #F3E9D6;
  --white: #FFFDF7;
  --teal: #17C3A6;
  --teal-deep: #0E8C79;
  --gold: #F2B441;
  --red: #A8453C;
  --slate: #5C7186;
  --sky: #7FB6D9;

  --line-dark: rgba(243, 233, 214, 0.14);
  --line-light: rgba(11, 26, 46, 0.16);
  --shadow-soft: 0 14px 34px rgba(4, 10, 18, 0.34);
  --shadow-card: 0 10px 26px rgba(4, 10, 18, 0.28);

  /* 尺寸 */
  --frame-w: 264px;
  --rail-h: 56px;
  --rail-h-scrolled: 48px;
  --bar-h: 64px;
  --cut: 18px;

  /* 字体 */
  --font-sans: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-mono: "JetBrains Mono", "IBM Plex Mono", "SFMono-Regular", Menlo, Consolas, "Courier New", monospace;

  --step-1: 14px;
  --step-2: 16px;
  --step-3: 20px;
  --step-4: 28px;
  --step-5: 40px;
  --step-6: 56px;
  --step-7: 72px;
}

/* ---------- 3. 基础排版 ---------- */
body {
  background-color: var(--night);
  background-image:
    radial-gradient(circle at 82% 6%, rgba(127, 182, 217, 0.10), transparent 46%),
    linear-gradient(180deg, #0B1A2E 0%, #0A1729 62%, #0B1A2E 100%);
  color: var(--paper);
  font-family: var(--font-sans);
  font-size: var(--step-2);
  font-weight: 400;
  line-height: 1.75;
  letter-spacing: 0.005em;
  min-height: 100vh;
}

h1, h2, h3, h4 {
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1.18;
  color: var(--white);
}

h1 { font-size: clamp(34px, 6vw, var(--step-6)); }
h2 { font-size: clamp(26px, 4vw, var(--step-5)); }
h3 { font-size: var(--step-4); }
h4 { font-size: var(--step-3); }

p { max-width: 68ch; }

strong, b { font-weight: 700; color: var(--white); }

code, kbd, samp, .mono {
  font-family: var(--font-mono);
  font-weight: 500;
  letter-spacing: 0.02em;
}

::selection {
  background: var(--teal);
  color: var(--night);
}

/* ---------- 4. 焦点与无障碍 ---------- */
:focus { outline: none; }

a:focus-visible,
button:focus-visible,
[tabindex]:focus-visible,
.tag:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: 2px;
  box-shadow: 0 0 0 4px rgba(242, 180, 65, 0.30);
  border-radius: 2px;
}

.skip-link {
  position: fixed;
  top: -72px;
  left: 16px;
  z-index: 200;
  padding: 11px 20px;
  background: var(--gold);
  color: var(--night);
  font-weight: 700;
  font-size: var(--step-1);
  text-decoration: none;
  letter-spacing: 0.04em;
  clip-path: polygon(0 0, calc(100% - 12px) 0, 100% 12px, 100% 100%, 12px 100%, 0 calc(100% - 12px));
  transition: top 0.18s ease;
}

.skip-link:focus {
  top: 14px;
}

/* ---------- 5. 外框导航（头部） ---------- */
.site-frame {
  --rail-current: var(--rail-h);
}

/* 5.1 顶缘状态条 */
.frame-rail {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 60;
  height: 44px;
  display: flex;
  align-items: center;
  padding: 0 16px;
  background: var(--ink);
  border-bottom: 1px solid var(--line-dark);
  transition: height 0.22s ease, background-color 0.22s ease;
}

.frame-rail__inner {
  flex: 1 1 auto;
  min-width: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.frame-rail__note {
  display: flex;
  align-items: center;
  gap: 9px;
  margin: 0;
  max-width: none;
  font-size: 13px;
  color: rgba(243, 233, 214, 0.86);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.rail-dot {
  flex: none;
  width: 9px;
  height: 9px;
  background: var(--teal);
  clip-path: polygon(0 0, 100% 0, 100% 68%, 50% 100%, 0 68%);
}

.frame-rail__meta {
  margin: 0;
  max-width: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--sky);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.frame-rail__progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  background: rgba(127, 182, 217, 0.18);
}

.frame-rail__bar {
  display: block;
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--teal) 0%, var(--sky) 45%, var(--gold) 100%);
  transition: width 0.12s linear;
}

/* 5.2 侧／底框架 */
.frame-side {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 80;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 12px;
  padding: 10px 14px calc(10px + env(safe-area-inset-bottom, 0px));
  min-height: var(--bar-h);
  background: rgba(17, 26, 36, 0.97);
  border-top: 1px solid var(--line-dark);
  box-shadow: 0 -12px 30px rgba(4, 10, 18, 0.45);
}

/* 5.3 品牌 */
.brand {
  order: 1;
  flex: 1 1 auto;
  min-width: 0;
  display: flex;
  align-items: center;
  gap: 11px;
  text-decoration: none;
  color: var(--paper);
}

.brand__mark {
  position: relative;
  flex: none;
  width: 34px;
  height: 34px;
  background: linear-gradient(135deg, var(--teal) 0%, var(--teal-deep) 100%);
  clip-path: polygon(0 0, 72% 0, 100% 28%, 100% 100%, 28% 100%, 0 72%);
}

.brand__mark::after {
  content: "";
  position: absolute;
  inset: 10px 12px 12px 10px;
  background: var(--night);
  clip-path: polygon(0 0, 100% 0, 100% 58%, 58% 100%, 0 100%);
}

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

.brand__line {
  font-size: 14.5px;
  font-weight: 900;
  letter-spacing: -0.01em;
  line-height: 1.3;
  color: var(--white);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.brand__sub {
  font-size: 11.5px;
  line-height: 1.35;
  letter-spacing: 0.05em;
  color: var(--slate);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.brand:hover .brand__line { color: var(--teal); }

/* 5.4 折叠按钮（仅移动端可见） */
.nav-toggle {
  order: 2;
  flex: none;
  display: none;
  align-items: center;
  gap: 9px;
  padding: 8px 14px;
  border: 1px solid rgba(243, 233, 214, 0.28);
  color: var(--paper);
  font-size: 13.5px;
  font-weight: 700;
  letter-spacing: 0.06em;
  cursor: pointer;
  clip-path: polygon(0 0, calc(100% - 10px) 0, 100% 10px, 100% 100%, 10px 100%, 0 calc(100% - 10px));
  transition: border-color 0.2s ease, color 0.2s ease, background-color 0.2s ease;
}

.nav-toggle__bars {
  position: relative;
  flex: none;
  width: 18px;
  height: 12px;
  border-top: 2px solid currentColor;
  border-bottom: 2px solid currentColor;
}

.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: 11px;
  height: 2px;
  background: currentColor;
  transform: translateY(-50%);
  transition: width 0.2s ease;
}

.site-frame[data-open="true"] .nav-toggle {
  border-color: var(--teal);
  color: var(--teal);
  background: rgba(23, 195, 166, 0.10);
}

.site-frame[data-open="true"] .nav-toggle__bars::after { width: 18px; }

/* 5.5 导航 */
.site-nav {
  order: 3;
  flex: 1 0 100%;
  display: none;
  padding: 14px 0 6px;
  border-top: 1px solid var(--line-dark);
}

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

.site-nav__list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px;
}

.site-nav__link {
  display: block;
  padding: 11px 13px;
  font-size: 14.5px;
  color: rgba(243, 233, 214, 0.78);
  text-decoration: none;
  border-left: 2px solid transparent;
  background: rgba(243, 233, 214, 0.03);
  transition: background-color 0.2s ease, color 0.2s ease, border-color 0.2s ease, transform 0.2s ease;
}

.site-nav__link:hover {
  background: rgba(23, 195, 166, 0.12);
  border-left-color: var(--teal-deep);
  color: var(--white);
  transform: translateX(2px);
}

.site-nav__link[aria-current="page"] {
  position: relative;
  background: rgba(23, 195, 166, 0.18);
  border-left-color: var(--teal);
  color: var(--white);
  font-weight: 700;
}

.site-nav__link[aria-current="page"]::after {
  content: "";
  position: absolute;
  right: 12px;
  top: 50%;
  width: 7px;
  height: 7px;
  margin-top: -3.5px;
  background: var(--gold);
  transform: rotate(45deg);
}

/* 5.6 快速入口 */
.frame-side__cta {
  order: 4;
  flex: 1 0 100%;
  display: none;
  padding: 12px 0 4px;
  border-top: 1px solid var(--line-dark);
}

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

.frame-side__label {
  margin: 0 0 9px;
  max-width: none;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--gold);
}

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

.quick-link {
  display: inline-block;
  padding: 7px 14px;
  font-size: 13.5px;
  letter-spacing: 0.02em;
  text-decoration: none;
  color: var(--paper);
  background: rgba(243, 233, 214, 0.06);
  border: 1px solid var(--line-dark);
  clip-path: polygon(0 0, calc(100% - 10px) 0, 100% 10px, 100% 100%, 10px 100%, 0 calc(100% - 10px));
  transition: background-color 0.2s ease, color 0.2s ease, transform 0.2s ease;
}

.quick-link:hover {
  background: var(--teal);
  border-color: var(--teal);
  color: var(--night);
  transform: translateY(-2px);
}

/* 5.7 滚动后的收窄状态 */
.site-frame[data-scrolled="true"] .frame-rail {
  background: rgba(17, 26, 36, 0.98);
}

/* ---------- 6. 页脚 ---------- */
.site-foot {
  position: relative;
  margin-top: 88px;
  padding: 64px 0 30px;
  background: var(--ink);
  background-image:
    linear-gradient(180deg, rgba(23, 195, 166, 0.06) 0%, transparent 34%),
    repeating-linear-gradient(-14deg, rgba(127, 182, 217, 0.045) 0 2px, transparent 2px 16px);
  color: var(--paper);
  clip-path: polygon(0 30px, 100% 0, 100% 100%, 0 100%);
}

.foot-panel {
  width: 100%;
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 20px;
  display: grid;
  grid-template-columns: 1fr;
  gap: 38px;
}

.foot-brand {
  display: flex;
  align-items: flex-start;
  gap: 14px;
}

.foot-brand__mark {
  position: relative;
  flex: none;
  width: 40px;
  height: 40px;
  background: linear-gradient(150deg, var(--gold) 0%, var(--teal-deep) 100%);
  clip-path: polygon(0 0, 72% 0, 100% 28%, 100% 100%, 28% 100%, 0 72%);
}

.foot-brand__mark::after {
  content: "";
  position: absolute;
  inset: 12px 14px 14px 12px;
  background: var(--ink);
  clip-path: polygon(0 0, 100% 0, 100% 58%, 58% 100%, 0 100%);
}

.foot-brand__text { min-width: 0; }

.foot-brand__line {
  margin: 0;
  max-width: none;
  font-size: 16px;
  font-weight: 900;
  letter-spacing: -0.01em;
  color: var(--white);
}

.foot-brand__sub {
  margin: 4px 0 0;
  max-width: none;
  font-size: 12.5px;
  letter-spacing: 0.06em;
  color: var(--slate);
}

.foot-cols {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(148px, 1fr));
  gap: 26px 22px;
}

.foot-col__title {
  margin: 0 0 14px;
  padding-bottom: 9px;
  font-size: 14px;
  font-weight: 900;
  letter-spacing: 0.08em;
  color: var(--teal);
  border-bottom: 1px solid var(--line-dark);
}

.foot-col__list {
  display: flex;
  flex-direction: column;
  gap: 9px;
}

.foot-col__link {
  position: relative;
  display: inline-block;
  padding-left: 15px;
  font-size: 14.5px;
  color: rgba(243, 233, 214, 0.74);
  text-decoration: none;
  transition: color 0.2s ease, transform 0.2s ease;
}

.foot-col__link::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.66em;
  width: 6px;
  height: 6px;
  background: var(--slate);
  transform: rotate(45deg);
  transition: background-color 0.2s ease;
}

.foot-col__link:hover {
  color: var(--white);
  transform: translateX(3px);
}

.foot-col__link:hover::before { background: var(--teal); }

.foot-meta {
  width: 100%;
  max-width: 1180px;
  margin: 42px auto 0;
  padding: 26px 20px 0;
  border-top: 1px solid var(--line-dark);
}

.foot-contact {
  margin: 0;
  max-width: none;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.02em;
  color: var(--sky);
  line-height: 1.9;
}

.foot-note {
  margin: 10px 0 0;
  max-width: 88ch;
  font-size: 13px;
  line-height: 1.8;
  color: rgba(243, 233, 214, 0.62);
}

.foot-bottom {
  margin-top: 24px;
  padding-top: 18px;
  border-top: 1px dashed rgba(243, 233, 214, 0.16);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px 22px;
}

.foot-icp {
  margin: 0;
  max-width: none;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.06em;
  color: var(--gold);
}

.foot-copy {
  margin: 0;
  max-width: none;
  font-size: 12.5px;
  color: var(--slate);
}

.foot-legal {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  margin-left: auto;
}

.foot-legal__link {
  font-size: 13px;
  color: rgba(243, 233, 214, 0.72);
  text-decoration: none;
  border-bottom: 1px solid rgba(243, 233, 214, 0.28);
  transition: color 0.2s ease, border-color 0.2s ease;
}

.foot-legal__link:hover {
  color: var(--teal);
  border-color: var(--teal);
}

/* ---------- 7. 通用组件 ---------- */
.container {
  width: 100%;
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 20px;
}

.section { padding: 56px 0; }
.section--tight { padding: 32px 0; }

/* 7.1 堆叠画板 */
.panel {
  --cut: 18px;
  position: relative;
  padding: 30px 22px;
  background: var(--paper);
  color: var(--night);
  box-shadow: var(--shadow-card);
  clip-path: polygon(0 0, calc(100% - var(--cut)) 0, 100% var(--cut), 100% 100%, var(--cut) 100%, 0 calc(100% - var(--cut)));
}

.panel p { color: rgba(17, 26, 36, 0.86); }
.panel h2, .panel h3, .panel h4 { color: var(--night); }

.panel--ink {
  background: var(--ink);
  color: var(--paper);
}

.panel--ink p { color: rgba(243, 233, 214, 0.82); }
.panel--ink h2, .panel--ink h3, .panel--ink h4 { color: var(--white); }

.panel--dark {
  background: linear-gradient(160deg, #0E2038 0%, var(--night) 55%, #0A1524 100%);
  color: var(--paper);
}

.panel--dark p { color: rgba(243, 233, 214, 0.82); }
.panel--dark h2, .panel--dark h3, .panel--dark h4 { color: var(--white); }

.panel--white {
  background: var(--white);
  color: var(--night);
}

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

.panel--stack {
  margin-top: var(--panel-shift, -24px);
}

.cut {
  clip-path: polygon(0 0, calc(100% - var(--cut, 18px)) 0, 100% var(--cut, 18px), 100% 100%, var(--cut, 18px) 100%, 0 calc(100% - var(--cut, 18px)));
}

/* 7.2 展览标签 */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 14px;
  padding: 5px 13px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 500;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--teal-deep);
  background: rgba(11, 26, 46, 0.07);
  border-left: 3px solid var(--teal);
}

.panel--dark .eyebrow,
.panel--ink .eyebrow {
  color: var(--teal);
  background: rgba(243, 233, 214, 0.08);
  border-left-color: var(--gold);
}

/* 7.3 数据卡 */
.stat {
  display: flex;
  flex-direction: column;
  gap: 7px;
  padding: 16px 18px;
  background: rgba(11, 26, 46, 0.05);
  border-left: 3px solid var(--gold);
}

.panel--dark .stat,
.panel--ink .stat {
  background: rgba(243, 233, 214, 0.06);
}

.stat__value {
  font-family: var(--font-mono);
  font-weight: 500;
  font-size: clamp(38px, 6vw, var(--step-7));
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--gold);
}

.stat__label {
  font-size: 13.5px;
  letter-spacing: 0.04em;
  color: var(--slate);
}

.panel--dark .stat__label,
.panel--ink .stat__label,
.stat--light .stat__label {
  color: rgba(243, 233, 214, 0.72);
}

.stat--teal .stat__value { color: var(--teal); }
.stat--red .stat__value { color: var(--red); }

/* 7.4 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 12px 24px;
  font-family: var(--font-sans);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.02em;
  text-decoration: none;
  border: 1px solid transparent;
  cursor: pointer;
  clip-path: polygon(0 0, calc(100% - 12px) 0, 100% 12px, 100% 100%, 12px 100%, 0 calc(100% - 12px));
  transition: background-color 0.2s ease, color 0.2s ease, border-color 0.2s ease, transform 0.2s ease;
}

.btn--primary {
  background: var(--teal);
  color: var(--night);
}

.btn--primary:hover {
  background: var(--teal-deep);
  color: var(--white);
}

.btn--ghost {
  background: transparent;
  border-color: rgba(243, 233, 214, 0.42);
  color: var(--paper);
}

.btn--ghost:hover {
  border-color: var(--gold);
  color: var(--gold);
}

.btn--dark {
  background: var(--night);
  color: var(--paper);
}

.btn--dark:hover {
  background: var(--teal-deep);
  color: var(--white);
}

.btn:hover { transform: translateY(-2px); }

/* 7.5 面包屑 */
.crumbs {
  margin: 0 0 20px;
  font-size: 13px;
  color: var(--slate);
}

.crumbs ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 7px;
}

.crumbs li {
  display: flex;
  align-items: center;
  gap: 7px;
}

.crumbs li + li::before {
  content: "/";
  color: var(--slate);
  opacity: 0.7;
}

.crumbs a {
  color: var(--sky);
  text-decoration: none;
}

.crumbs a:hover {
  color: var(--teal);
  text-decoration: underline;
}

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

/* 7.6 图片容器（页面阶段放图） */
.media-frame {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  background: linear-gradient(140deg, var(--night) 0%, var(--ink) 52%, var(--teal-deep) 100%);
  clip-path: polygon(0 0, calc(100% - var(--cut, 18px)) 0, 100% var(--cut, 18px), 100% 100%, 0 100%);
}

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

.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: repeating-linear-gradient(-14deg, rgba(127, 182, 217, 0.07) 0 2px, transparent 2px 13px);
}

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

.media-frame__caption {
  position: absolute;
  z-index: 1;
  left: 0;
  bottom: 0;
  margin: 0;
  max-width: 100%;
  padding: 9px 15px;
  background: rgba(17, 26, 36, 0.9);
  color: var(--paper);
  font-size: 12.5px;
  letter-spacing: 0.04em;
  border-left: 3px solid var(--gold);
}

/* 7.7 标签筛选 */
.tag-group {
  display: flex;
  flex-wrap: wrap;
  gap: 9px;
}

.tag {
  display: inline-flex;
  align-items: center;
  padding: 7px 15px;
  font-size: 13.5px;
  letter-spacing: 0.02em;
  color: var(--night);
  background: rgba(11, 26, 46, 0.05);
  border: 1px solid var(--line-light);
  cursor: pointer;
  transition: background-color 0.2s ease, color 0.2s ease, border-color 0.2s ease, transform 0.2s ease;
}

.panel--dark .tag,
.panel--ink .tag {
  color: var(--paper);
  background: rgba(243, 233, 214, 0.06);
  border-color: var(--line-dark);
}

.tag:hover {
  border-color: var(--teal);
  color: var(--teal-deep);
  transform: translateY(-2px);
}

.panel--dark .tag:hover,
.panel--ink .tag:hover { color: var(--teal); }

.tag[aria-pressed="true"],
.tag--active {
  background: var(--teal);
  border-color: var(--teal);
  color: var(--night);
  font-weight: 700;
}

/* 7.8 运动轨迹分隔 */
.trace {
  height: 2px;
  margin: 28px 0;
  background: linear-gradient(90deg, var(--teal) 0%, var(--sky) 38%, var(--gold) 62%, transparent 100%);
  opacity: 0.85;
}

.trace--slant { transform: rotate(-1.4deg); }

/* 7.9 滚动显现 */
html[data-reveal="on"] .reveal {
  opacity: 0;
  transform: translateY(14px);
}

html[data-reveal="on"] .reveal[data-visible="true"] {
  opacity: 1;
  transform: none;
  transition: opacity 0.45s ease, transform 0.45s ease;
}

/* ---------- 8. 响应式 ---------- */
@media (max-width: 639px) {
  .frame-rail__meta { display: none; }
}

/* 移动端主体留白 */
@media (max-width: 1023px) {
  body {
    padding-top: 44px;
    padding-bottom: calc(var(--bar-h) + 26px);
  }

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

  .frame-side {
    max-height: 86vh;
    overflow-y: auto;
  }

  .site-nav,
  .frame-side__cta {
    max-height: 60vh;
    overflow-y: auto;
  }

  .site-nav { max-height: none; }
}

/* 桌面：左竖框 + 顶轨 */
@media (min-width: 1024px) {
  body {
    padding-top: var(--rail-h);
    padding-left: var(--frame-w);
  }

  .frame-rail {
    left: var(--frame-w);
    height: var(--rail-h);
    padding: 0 28px;
  }

  .site-frame[data-scrolled="true"] .frame-rail {
    height: var(--rail-h-scrolled);
  }

  .frame-side {
    top: 0;
    right: auto;
    bottom: 0;
    width: var(--frame-w);
    min-height: 0;
    flex-direction: column;
    flex-wrap: nowrap;
    align-items: stretch;
    gap: 20px;
    padding: 26px 20px 30px;
    background: linear-gradient(180deg, var(--ink) 0%, #0D1725 58%, var(--night) 100%);
    border-top: 0;
    border-right: 1px solid var(--line-dark);
    box-shadow: none;
    overflow-y: auto;
  }

  .frame-side::after {
    content: "";
    position: absolute;
    top: 0;
    bottom: 0;
    right: -1px;
    width: 3px;
    pointer-events: none;
    background: linear-gradient(180deg, var(--teal) 0%, var(--sky) 34%, var(--gold) 56%, var(--red) 74%, transparent 100%);
    opacity: 0.9;
  }

  .brand {
    order: 0;
    flex: none;
  }

  .brand__line { font-size: 15px; }

  .nav-toggle { display: none; }

  .site-nav {
    order: 0;
    flex: none;
    display: block;
    padding: 18px 0 0;
    border-top: 1px solid var(--line-dark);
    max-height: none;
    overflow: visible;
  }

  .site-nav__list {
    display: flex;
    flex-direction: column;
    gap: 5px;
  }

  .site-nav__link {
    padding: 10px 13px;
    background: transparent;
    font-size: 15px;
  }

  .frame-side__cta {
    order: 0;
    flex: none;
    display: block;
    margin-top: auto;
    padding: 16px 0 0;
    border-top: 1px solid var(--line-dark);
  }

  .quick-list { flex-direction: column; }

  .quick-link { display: block; text-align: center; }

  .panel { padding: 48px 46px; --cut: 24px; }

  .section { padding: 84px 0; }
  .section--tight { padding: 48px 0; }

  .container { padding: 0 40px; }

  .foot-panel {
    padding: 0 40px;
    grid-template-columns: minmax(230px, 1fr) 2.2fr;
    align-items: start;
  }

  .foot-meta { padding: 26px 40px 0; }

  .foot-bottom { gap: 16px 26px; }
}

@media (min-width: 1280px) {
  .site-foot { margin-top: 120px; }
  .foot-panel { gap: 56px; }
}

/* ---------- 9. 减少动态效果 ---------- */
@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;
    scroll-behavior: auto !important;
  }

  html[data-reveal="on"] .reveal,
  html[data-reveal="on"] .reveal[data-visible="true"] {
    opacity: 1;
    transform: none;
  }

  .btn:hover,
  .tag:hover,
  .quick-link:hover,
  .foot-col__link:hover,
  .site-nav__link:hover {
    transform: none;
  }
}