/* ==========================================================================
   月博会员主站 · 共享样式表  /assets/site.css
   底色：深空靛青 / 主色：月相银蓝 / 点色：暖金刻度
   ========================================================================== */

/* --- 1. 重置 ------------------------------------------------------------ */
*,
*::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, 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; text-decoration: none; }
table { border-collapse: collapse; width: 100%; }

/* --- 2. 设计变量 -------------------------------------------------------- */
:root {
  --ink: #0B1633;          /* 深空靛青 */
  --night: #101E42;        /* 夜幕靛蓝 */
  --moon: #A8C6E8;         /* 月相银蓝 */
  --silver: #E6EDF6;       /* 冷银白 */
  --paper: #F3EEE2;        /* 档案米白 */
  --gold: #D9A441;         /* 暖金刻度 */
  --mist: #6E7E99;         /* 雾灰蓝 */
  --brown: #241C14;        /* 深棕黑墨 */
  --verify: #3E8E7E;       /* 校验青 */
  --review: #C2543B;       /* 复核橙红 */

  --line: rgba(168, 198, 232, .18);
  --line-strong: rgba(168, 198, 232, .40);
  --line-paper: rgba(36, 28, 20, .14);

  --font-display: "Source Han Sans SC", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-body: system-ui, -apple-system, "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-mono: ui-monospace, "JetBrains Mono", "SFMono-Regular", Menlo, Consolas, "Liberation Mono", monospace;

  --radius-s: 8px;
  --radius-m: 16px;
  --radius-l: 24px;
  --radius-xl: 32px;
  --radius-pill: 999px;

  --wrap: 1280px;
  --gutter: clamp(1.1rem, 4vw, 2.5rem);
  --ease: cubic-bezier(.2, .7, .3, 1);
  --dur: 240ms;
}

/* --- 3. 基础排版 -------------------------------------------------------- */
body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  background: var(--ink);
  color: var(--silver);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.75;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

main { flex: 1 0 auto; }

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 800;
  font-stretch: condensed;
  line-height: 1.16;
  letter-spacing: -.01em;
  text-wrap: balance;
}

p { text-wrap: pretty; }

strong { color: var(--moon); font-weight: 600; }

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

:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: 3px;
  border-radius: 6px;
}

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

/* --- 4. 跳转链接 -------------------------------------------------------- */
.skip-link {
  position: fixed;
  top: .6rem;
  left: .6rem;
  z-index: 999;
  transform: translateY(-160%);
  padding: .6rem 1rem;
  border-radius: var(--radius-pill);
  background: var(--gold);
  color: #1c1408;
  font-size: .85rem;
  font-weight: 700;
  transition: transform 180ms var(--ease);
}
.skip-link:focus-visible,
.skip-link:focus { transform: translateY(0); }

/* --- 5. 容器与网格 ------------------------------------------------------ */
.container {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.container--narrow { max-width: 880px; }

.grid { display: grid; gap: clamp(1.25rem, 3vw, 2.25rem); }
.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)); }

/* --- 6. 页头 ------------------------------------------------------------ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 120;
  background: transparent;
  transition: background-color var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}
.site-header[data-scrolled] {
  background: rgba(11, 22, 51, .94);
  -webkit-backdrop-filter: saturate(140%) blur(12px);
  backdrop-filter: saturate(140%) blur(12px);
  box-shadow: 0 20px 44px -32px rgba(0, 0, 0, .95);
}

/* 顶部轮值 / 序列号条 */
.header-meta {
  max-height: 52px;
  overflow: hidden;
  border-bottom: 1px solid rgba(168, 198, 232, .12);
  transition: max-height var(--dur) var(--ease),
              opacity 180ms linear,
              border-color var(--dur) linear;
}
.site-header[data-scrolled] .header-meta {
  max-height: 0;
  opacity: 0;
  border-color: transparent;
}
.header-meta__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: .4rem 1.5rem;
  min-height: 44px;
  padding-block: .4rem;
}
.header-meta__status {
  display: inline-flex;
  align-items: center;
  gap: .55rem;
  font-size: .78rem;
  letter-spacing: .06em;
  color: var(--mist);
}
.pulse {
  flex: none;
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--verify);
  box-shadow: 0 0 0 3px rgba(62, 142, 126, .18);
}
.header-meta__serial {
  font-family: var(--font-mono);
  font-size: .74rem;
  letter-spacing: .18em;
  color: var(--mist);
  white-space: nowrap;
}
.header-meta__label {
  margin-right: .45rem;
  letter-spacing: .2em;
  color: rgba(168, 198, 232, .5);
}
.header-meta__key {
  margin-inline: .12em;
  padding: 0 .2em;
  border: 1px solid rgba(217, 164, 65, .6);
  border-radius: 3px;
  color: var(--gold);
}

/* 品牌 + 导航行 */
.header-bar { position: relative; }
.header-bar__inner {
  display: flex;
  align-items: center;
  gap: clamp(.9rem, 3vw, 2rem);
  min-height: 68px;
  padding-block: .45rem;
  transition: min-height var(--dur) var(--ease);
}
.site-header[data-scrolled] .header-bar__inner { min-height: 56px; }

/* 品牌 */
.brand {
  display: inline-flex;
  align-items: center;
  gap: .7rem;
  min-width: 0;
  flex: none;
  color: var(--silver);
}
.brand__mark {
  position: relative;
  flex: none;
  width: 40px; height: 40px;
  border-radius: 13px;
  border: 1px solid var(--line-strong);
  background: linear-gradient(155deg, #17264f, #0a1229);
}
.brand__mark::before,
.brand__mark::after {
  content: "";
  position: absolute;
  inset: 0;
  margin: auto;
  width: 18px; height: 18px;
  border-radius: 50%;
}
.brand__mark::before { background: var(--moon); }
.brand__mark::after { background: #0a1229; transform: translate(6px, -4px); }
.brand__mark-key {
  position: absolute;
  right: -3px; bottom: -3px;
  width: 9px; height: 9px;
  border-radius: 2px;
  background: var(--gold);
  box-shadow: 0 0 0 2px var(--ink);
}
.brand__text {
  display: flex;
  flex-direction: column;
  min-width: 0;
  line-height: 1.25;
}
.brand__line {
  font-family: var(--font-display);
  font-weight: 800;
  font-stretch: condensed;
  font-size: clamp(1.05rem, 2.1vw, 1.28rem);
  letter-spacing: .02em;
  color: var(--silver);
}
.brand__descriptor {
  font-size: .68rem;
  letter-spacing: .07em;
  color: var(--mist);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* 移动导航按钮 */
.nav-toggle {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  margin-left: auto;
  padding: .5rem .85rem;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-pill);
  color: var(--moon);
  cursor: pointer;
  transition: border-color 180ms linear, color 180ms linear, background-color 180ms linear;
}
.nav-toggle:hover { border-color: var(--gold); color: var(--gold); }
.nav-toggle__bars {
  display: flex;
  flex-direction: column;
  gap: 3.5px;
  width: 16px;
}
.nav-toggle__bars span {
  display: block;
  height: 1.5px;
  border-radius: 2px;
  background: currentColor;
  transition: transform var(--dur) var(--ease), opacity 160ms linear;
}
.nav-toggle__text { font-size: .76rem; letter-spacing: .12em; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(1) { transform: translateY(5px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(3) { transform: translateY(-5px) rotate(-45deg); }

/* 导航：移动端为下拉面板 */
.site-nav {
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  display: none;
  flex-direction: column;
  gap: .35rem;
  padding: 1rem clamp(1.1rem, 5vw, 2rem) 1.4rem;
  background: var(--ink);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line-strong);
  box-shadow: 0 30px 60px -30px rgba(0, 0, 0, .95);
}
.site-nav[data-open] {
  display: flex;
  animation: nav-in 240ms var(--ease) both;
}
@keyframes nav-in {
  from { opacity: 0; transform: translateY(-8px); }
  to { opacity: 1; transform: none; }
}
.site-nav__list {
  display: flex;
  flex-direction: column;
  gap: .1rem;
}
.site-nav__item { border-bottom: 1px solid rgba(168, 198, 232, .1); }
.site-nav__link {
  position: relative;
  display: block;
  padding: .7rem .2rem .7rem 1.15rem;
  color: rgba(230, 237, 246, .84);
  font-size: .98rem;
  letter-spacing: .03em;
  transition: color 160ms linear;
}
.site-nav__link::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: 6px; height: 1px;
  background: var(--mist);
  transform: translateY(-50%);
  transition: background-color 160ms linear, width 160ms var(--ease);
}
.site-nav__link:hover { color: var(--moon); }
.site-nav__link:hover::before { width: 14px; background: var(--gold); }
.site-nav__link[aria-current="page"] { color: var(--gold); }
.site-nav__link[aria-current="page"]::before { width: 16px; height: 2px; background: var(--gold); }
.site-nav__cta { margin-top: .9rem; justify-content: center; }

/* 页头刻度轨与滚动进度 */
.header-rail {
  position: relative;
  border-bottom: 1px solid rgba(168, 198, 232, .1);
}
.header-rail__inner {
  display: grid;
  grid-template-columns: repeat(16, minmax(0, 1fr));
  align-items: end;
  height: 11px;
}
.rail-tick {
  display: block;
  width: 1px;
  height: 5px;
  justify-self: start;
  background: rgba(168, 198, 232, .26);
}
.rail-tick.is-key {
  width: 2px;
  height: 11px;
  background: var(--gold);
}
.header-progress {
  position: absolute;
  left: 0;
  bottom: -1px;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, rgba(217, 164, 65, .18), var(--gold));
  transform: scaleX(0);
  transform-origin: 0 50%;
  pointer-events: none;
}

/* --- 7. 按钮 ------------------------------------------------------------ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: .5rem;
  padding: .72rem 1.3rem;
  border: 1px solid transparent;
  border-radius: var(--radius-pill);
  font-size: .92rem;
  font-weight: 600;
  letter-spacing: .04em;
  cursor: pointer;
  transition: background-color 180ms linear, color 180ms linear,
              border-color 180ms linear, transform 180ms var(--ease);
}
.btn--gold { background: var(--gold); color: #1c1408; }
.btn--gold:hover { background: #e6b557; }
.btn--ghost { border-color: var(--line-strong); color: var(--moon); }
.btn--ghost:hover { border-color: var(--gold); color: var(--gold); }
.btn--paper { background: var(--paper); color: var(--brown); }
.btn--paper:hover { background: #fffaf0; }

/* --- 8. 章节结构 -------------------------------------------------------- */
.section { padding-block: clamp(3rem, 7vw, 6.5rem); }
.section__head {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: .6rem 1rem;
  margin-bottom: clamp(1.25rem, 3vw, 2.25rem);
}
.section__num {
  font-family: var(--font-mono);
  font-size: .8rem;
  letter-spacing: .2em;
  color: var(--gold);
}
.section__title {
  font-size: clamp(1.6rem, 3.4vw, 2.6rem);
  margin: 0;
}
.section__note {
  flex: 1 1 22ch;
  min-width: 18ch;
  color: var(--mist);
  font-size: .9rem;
  line-height: 1.65;
}

/* --- 9. 纸面阅读区 ------------------------------------------------------ */
.reading {
  position: relative;
  background: var(--paper);
  color: var(--brown);
  border-radius: var(--radius-xl) var(--radius-xl) 0 0;
}
.reading::before {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  pointer-events: none;
  opacity: .5;
  background-image: repeating-linear-gradient(
    0deg,
    rgba(36, 28, 20, .035) 0 1px,
    transparent 1px 4px
  );
}
.reading > * { position: relative; }
.reading h1, .reading h2, .reading h3, .reading h4 { color: var(--brown); }
.reading .section__num { color: #8a6216; }
.reading .section__note { color: #6b6055; }
.reading a:not(.btn) {
  color: var(--ink);
  border-bottom: 1px solid rgba(217, 164, 65, .7);
}
.reading a:not(.btn):hover { border-bottom-color: var(--ink); }

/* --- 10. 卡片 / 标签 / 状态 -------------------------------------------- */
.card {
  position: relative;
  padding: clamp(1.15rem, 2.6vw, 1.7rem);
  border: 1px solid var(--line);
  border-radius: var(--radius-l);
  background: var(--night);
}
.card--paper {
  background: #FBF7EE;
  border-color: var(--line-paper);
  color: var(--brown);
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  padding: .28rem .7rem;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-pill);
  font-size: .78rem;
  letter-spacing: .06em;
  color: var(--moon);
}

.status {
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  font-size: .78rem;
  letter-spacing: .06em;
  color: var(--mist);
}
.status::before {
  content: "";
  width: 6px; height: 6px;
  border-radius: 2px;
  background: currentColor;
}
.status--ok { color: var(--verify); }
.status--review { color: var(--review); }

/* --- 11. 序列号分解 ----------------------------------------------------- */
.serial {
  display: flex;
  flex-wrap: wrap;
  gap: .3rem;
  font-family: var(--font-mono);
  font-size: .9rem;
  letter-spacing: .14em;
}
.serial__digit {
  min-width: 2.1em;
  padding: .18rem .35rem;
  border: 1px solid var(--line);
  border-radius: var(--radius-s);
  background: rgba(16, 30, 66, .7);
  text-align: center;
  color: var(--moon);
}
.serial__digit--key {
  border-color: var(--gold);
  background: rgba(217, 164, 65, .14);
  color: var(--gold);
}

/* --- 12. 筛选与标签切换 ------------------------------------------------- */
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem;
  margin-bottom: clamp(1.25rem, 3vw, 2rem);
}
.filter-btn {
  padding: .45rem .95rem;
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  color: var(--mist);
  font-size: .82rem;
  letter-spacing: .06em;
  cursor: pointer;
  transition: color 160ms linear, border-color 160ms linear, background-color 160ms linear;
}
.filter-btn:hover { color: var(--moon); border-color: var(--line-strong); }
.filter-btn[aria-pressed="true"] {
  color: var(--ink);
  background: var(--gold);
  border-color: var(--gold);
}
[data-filter-item][hidden] { display: none; }

[data-tabs] { display: block; }
.tabs__list,
[data-tabs] > [role="tablist"] {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem;
  border-bottom: 1px solid var(--line);
  padding-bottom: .75rem;
  margin-bottom: 1.5rem;
}
[data-tab] {
  padding: .5rem 1rem;
  border: 1px solid transparent;
  border-radius: var(--radius-pill);
  color: var(--mist);
  font-size: .85rem;
  letter-spacing: .05em;
  cursor: pointer;
  transition: color 160ms linear, border-color 160ms linear, background-color 160ms linear;
}
[data-tab]:hover { color: var(--moon); }
[data-tab][aria-selected="true"] {
  color: var(--gold);
  border-color: rgba(217, 164, 65, .55);
  background: rgba(217, 164, 65, .1);
}
[data-tab-panel][hidden] { display: none; }

/* --- 13. 面包屑 --------------------------------------------------------- */
.breadcrumbs {
  font-family: var(--font-mono);
  font-size: .74rem;
  letter-spacing: .12em;
  color: var(--mist);
}
.breadcrumbs ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .1rem;
}
.breadcrumbs li { display: inline-flex; align-items: center; }
.breadcrumbs li + li::before {
  content: "/";
  margin-inline: .55rem;
  color: rgba(168, 198, 232, .35);
}
.breadcrumbs a { color: var(--moon); }
.breadcrumbs a:hover { color: var(--gold); }

/* --- 14. 图片容器基础规则 ---------------------------------------------- */
.figure {
  position: relative;
  margin: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius-l);
  background: linear-gradient(150deg, var(--night), #0a1730);
  overflow: hidden;
}
.figure__frame {
  position: relative;
  aspect-ratio: 16 / 10;
  overflow: hidden;
}
.figure__frame > img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.figure--tall .figure__frame { aspect-ratio: 4 / 5; }
.figure--wide .figure__frame { aspect-ratio: 21 / 9; }
.figure__slot {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  border: 1px dashed rgba(168, 198, 232, .35);
  border-radius: inherit;
  color: var(--mist);
  font-family: var(--font-mono);
  font-size: .75rem;
  letter-spacing: .16em;
}
.figure__caption {
  padding: .7rem 1rem .85rem;
  border-top: 1px solid var(--line);
  font-size: .78rem;
  letter-spacing: .04em;
  color: var(--mist);
  background: rgba(11, 22, 51, .6);
}
.figure--paper {
  background: #FBF7EE;
  border-color: var(--line-paper);
}
.figure--paper .figure__caption {
  background: rgba(36, 28, 20, .04);
  border-top-color: var(--line-paper);
  color: #6b6055;
}
.figure--paper .figure__slot { border-color: rgba(36, 28, 20, .3); color: #6b6055; }

/* --- 15. 表格 ----------------------------------------------------------- */
.table { font-size: .9rem; }
.table caption {
  margin-bottom: .75rem;
  font-size: .8rem;
  letter-spacing: .1em;
  color: var(--mist);
  text-align: left;
}
.table th {
  font-family: var(--font-mono);
  font-size: .75rem;
  letter-spacing: .12em;
  font-weight: 500;
  color: var(--moon);
  text-align: left;
  padding: .7rem .8rem;
  border-bottom: 1px solid var(--line-strong);
}
.table td {
  padding: .7rem .8rem;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
}
.table tbody tr:nth-child(even) { background: rgba(16, 30, 66, .55); }

/* --- 16. 显现动效 ------------------------------------------------------- */
.js [data-reveal] {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity .6s var(--ease), transform .6s var(--ease);
  will-change: opacity, transform;
}
.js [data-reveal].is-in {
  opacity: 1;
  transform: none;
  will-change: auto;
}

/* --- 17. 页脚 ----------------------------------------------------------- */
.site-footer {
  position: relative;
  background: linear-gradient(180deg, var(--ink), #07101f);
  padding-top: 0;
}

.footer-ridge {
  display: flex;
  align-items: flex-start;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--gutter);
  height: 32px;
  border-top: 1px solid var(--line);
}
.footer-ridge__tick {
  flex: 1 1 0;
  height: 4px;
  border-left: 1px solid rgba(168, 198, 232, .26);
}
.footer-ridge__tick:nth-child(2) { height: 7px; }
.footer-ridge__tick:nth-child(3) { height: 10px; }
.footer-ridge__tick:nth-child(4) { height: 13px; }
.footer-ridge__tick:nth-child(5) { height: 16px; }
.footer-ridge__tick:nth-child(6) { height: 19px; }
.footer-ridge__tick:nth-child(7) { height: 23px; }
.footer-ridge__tick:nth-child(8) { height: 27px; }
.footer-ridge__tick:nth-child(9) {
  flex: 0 0 2px;
  height: 31px;
  border-left: 0;
  background: var(--gold);
}

.footer-inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1.9fr) minmax(0, 1.1fr);
  gap: clamp(1.75rem, 4vw, 3.25rem);
  padding-block: clamp(2.5rem, 6vw, 4rem);
}

.footer-lead__brand {
  font-family: var(--font-display);
  font-weight: 800;
  font-stretch: condensed;
  font-size: clamp(1.25rem, 2.6vw, 1.6rem);
  letter-spacing: -.01em;
  color: var(--silver);
}
.footer-lead__desc {
  margin-top: .55rem;
  max-width: 22ch;
  font-family: var(--font-mono);
  font-size: .78rem;
  line-height: 1.9;
  letter-spacing: .08em;
  color: var(--mist);
}

.footer-nav {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1.5rem;
}
.footer-col__title {
  margin-bottom: .9rem;
  font-family: var(--font-mono);
  font-size: .74rem;
  letter-spacing: .2em;
  color: var(--moon);
}
.footer-links {
  display: flex;
  flex-direction: column;
  gap: .55rem;
}
.footer-links a {
  position: relative;
  display: inline-block;
  padding-left: .9rem;
  font-size: .9rem;
  color: rgba(230, 237, 246, .8);
  transition: color 160ms linear;
}
.footer-links a::before {
  content: "";
  position: absolute;
  left: 0;
  top: .85em;
  width: 6px;
  height: 1px;
  background: var(--mist);
  transition: width 160ms var(--ease), background-color 160ms linear;
}
.footer-links a:hover { color: var(--moon); }
.footer-links a:hover::before { width: 12px; background: var(--gold); }

.footer-contact__list {
  display: flex;
  flex-direction: column;
  gap: .7rem;
  align-items: flex-start;
}
.copy-btn {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  padding: .15rem 0;
  border-bottom: 1px dashed rgba(168, 198, 232, .35);
  color: var(--moon);
  font-family: var(--font-mono);
  font-size: .8rem;
  letter-spacing: .07em;
  cursor: pointer;
  text-align: left;
  transition: color 180ms linear, border-color 180ms linear;
}
.copy-btn::before {
  content: "";
  flex: none;
  width: 5px; height: 5px;
  border-radius: 1px;
  background: var(--gold);
}
.copy-btn:hover { color: var(--gold); border-bottom-color: var(--gold); }
.copy-btn[data-copied] { color: var(--verify); border-bottom-color: var(--verify); }
.copy-btn__hint {
  font-family: var(--font-body);
  font-size: .7rem;
  letter-spacing: .06em;
  color: var(--mist);
}
.copy-btn[data-copied] .copy-btn__hint { color: var(--verify); }

.footer-contact__addr {
  display: block;
  padding-left: .9rem;
  font-size: .84rem;
  color: rgba(230, 237, 246, .72);
}
.footer-contact__note {
  margin-top: .9rem;
  max-width: 30ch;
  font-size: .78rem;
  line-height: 1.7;
  color: var(--mist);
}

.footer-legal {
  border-top: 1px solid var(--line);
  background: rgba(4, 9, 20, .6);
}
.footer-legal__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .4rem 1.5rem;
  padding-block: 1rem;
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .1em;
  color: var(--mist);
}
.footer-legal__icp { color: rgba(168, 198, 232, .65); }
.footer-legal__note {
  flex: 1 1 20ch;
  min-width: 16ch;
  font-family: var(--font-body);
  letter-spacing: .04em;
  color: rgba(110, 126, 153, .9);
}

/* --- 18. 响应式 --------------------------------------------------------- */
@media (max-width: 1080px) {
  .grid--4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 1000px) {
  .footer-inner { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
  .footer-lead { grid-column: 1 / -1; }
  .footer-lead__desc { max-width: none; }
}

@media (max-width: 900px) {
  .grid--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .site-header { background: rgba(11, 22, 51, .82); }
  .header-meta { border-bottom-color: rgba(168, 198, 232, .16); }
}

@media (max-width: 640px) {
  body { font-size: 16px; }
  .grid--2,
  .grid--3,
  .grid--4 { grid-template-columns: minmax(0, 1fr); }
  .footer-inner { grid-template-columns: minmax(0, 1fr); }
  .footer-nav { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .header-meta__serial { display: none; }
  .brand__descriptor { display: none; }
  .reading { border-radius: var(--radius-l) var(--radius-l) 0 0; }
}

@media (max-width: 400px) {
  .nav-toggle__text { display: none; }
  .footer-nav { grid-template-columns: minmax(0, 1fr); }
}

/* --- 19. 桌面导航展开 --------------------------------------------------- */
@media (min-width: 901px) {
  .nav-toggle { display: none; }
  .site-nav {
    position: static;
    display: flex;
    flex-direction: row;
    align-items: center;
    gap: .2rem;
    margin-left: auto;
    padding: 0;
    background: none;
    border: 0;
    box-shadow: none;
    animation: none;
  }
  .site-nav[data-open] { display: flex; }
  .site-nav__list { flex-direction: row; gap: .2rem; }
  .site-nav__item { border-bottom: 0; }
  .site-nav__link {
    padding: .45rem .75rem .55rem;
    font-size: .92rem;
  }
  .site-nav__link::before {
    left: .75rem;
    right: .75rem;
    top: auto;
    bottom: .15rem;
    width: 0;
    height: 2px;
    transform: none;
    background: var(--gold);
    transition: width 200ms var(--ease);
  }
  .site-nav__link:hover::before,
  .site-nav__link[aria-current="page"]::before { width: calc(100% - 1.5rem); }
  .site-nav__link[aria-current="page"] { color: var(--gold); }
  .site-nav__cta {
    margin-top: 0;
    margin-left: .9rem;
    padding: .55rem 1.1rem;
    font-size: .84rem;
  }
}

/* --- 20. 减少动效 ------------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,
  *::before,
  *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }
  .js [data-reveal] {
    opacity: 1;
    transform: none;
    transition: none;
  }
}