/* ==========================================================================
   必一娱乐 · 共享样式表 /assets/site.css
   岩灰夜幕底 + 纸张叠层 + 坐标刻度
   ========================================================================== */

:root {
  --rock: #12161C;
  --mist: #2A3542;
  --haze: #7A8798;
  --paper: #F2EDE4;
  --neon: #FF5A3C;
  --clay: #B8613F;
  --river: #2F8F7C;
  --moss: #4C6B4E;
  --fluoro: #E8F04B;
  --pale: #DCE3EA;
  --grain: #C9C0B2;

  --rail-w: 88px;
  --shell-max: 1440px;
  --pad-x: clamp(20px, 4.2vw, 64px);

  --font-display: "PingFang SC", "Hiragino Sans GB", "Noto Sans SC",
    "Source Han Sans SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-body: var(--font-display);
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas,
    "Liberation Mono", monospace;

  --gap-1: 8px;
  --gap-2: 16px;
  --gap-3: 24px;
  --gap-4: 48px;
  --gap-5: 72px;
  --gap-6: 112px;

  --edge: rgba(122, 135, 152, 0.28);
  --edge-soft: rgba(122, 135, 152, 0.16);
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 128px;
}

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

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

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

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

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

table { border-collapse: collapse; }

:focus-visible {
  outline: 2px solid var(--fluoro);
  outline-offset: 3px;
  border-radius: 1px;
}

/* ------------------------------ 页面基底 -------------------------------- */
body {
  min-height: 100vh;
  background-color: var(--rock);
  background-image:
    radial-gradient(rgba(122, 135, 152, 0.10) 1px, transparent 1px),
    linear-gradient(180deg, rgba(42, 53, 66, 0.55) 0%, rgba(18, 22, 28, 0) 420px);
  background-size: 22px 22px, 100% 100%;
  color: var(--paper);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.85;
  font-weight: 400;
  letter-spacing: 0.01em;
  overflow-x: hidden;
}

.page-main {
  display: block;
  margin-inline-start: var(--rail-w);
  min-width: 0;
}

.shell {
  width: 100%;
  max-width: var(--shell-max);
  margin-inline: auto;
  padding-inline: var(--pad-x);
}

.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;
}

/* ------------------------------ 跳转链接 -------------------------------- */
.skip-link {
  position: fixed;
  top: 8px;
  left: 8px;
  z-index: 200;
  padding: 10px 18px;
  background: var(--fluoro);
  color: var(--rock);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.12em;
  transform: translateY(-160%);
  transition: transform 0.24s var(--ease);
}

.skip-link:focus {
  transform: translateY(0);
}

/* ------------------------------ 左侧导览轨道 ---------------------------- */
.rail {
  position: fixed;
  inset-block: 0;
  inset-inline-start: 0;
  width: var(--rail-w);
  z-index: 60;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
  padding: 22px 0 26px;
  background: var(--mist);
  border-inline-end: 1px solid var(--edge);
  pointer-events: none;
}

.rail__mark {
  writing-mode: vertical-rl;
  font-family: var(--font-display);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.34em;
  color: var(--paper);
}

.rail__coord {
  writing-mode: vertical-rl;
  font-family: var(--font-mono);
  font-size: 9px;
  letter-spacing: 0.24em;
  color: var(--haze);
}

.rail__nodes {
  margin-block: auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 18px;
}

.rail__node {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
}

.rail__dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--haze);
  transition: background 0.3s var(--ease), box-shadow 0.3s var(--ease);
}

.rail__code {
  font-family: var(--font-mono);
  font-size: 9px;
  letter-spacing: 0.14em;
  color: var(--haze);
  transition: color 0.3s var(--ease);
}

.rail__node[data-active="true"] .rail__dot {
  background: var(--fluoro);
  box-shadow: 0 0 0 4px rgba(232, 240, 75, 0.16);
}

.rail__node[data-active="true"] .rail__code {
  color: var(--fluoro);
}

.rail__track {
  position: relative;
  width: 2px;
  height: 84px;
  background: rgba(122, 135, 152, 0.24);
  overflow: hidden;
}

.rail__fill {
  position: absolute;
  inset-inline: 0;
  top: 0;
  height: 0;
  background: var(--neon);
  transition: height 0.18s linear;
}

.rail__pct {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.14em;
  color: var(--pale);
}

/* ------------------------------ 头部 ----------------------------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  margin-inline-start: var(--rail-w);
  background: rgba(18, 22, 28, 0.94);
  border-bottom: 1px solid var(--edge);
}

.header-top {
  background: var(--mist);
  border-bottom: 1px solid var(--edge-soft);
}

.header-top__inner {
  max-width: var(--shell-max);
  margin-inline: auto;
  padding: 10px var(--pad-x);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  min-height: 46px;
}

.brand {
  display: inline-flex;
  align-items: baseline;
  gap: 14px;
  min-width: 0;
}

.brand__mark {
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 600;
  letter-spacing: 0.18em;
  color: var(--paper);
  white-space: nowrap;
}

.brand__coord {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--haze);
  white-space: nowrap;
}

.header-tagline {
  flex: 1 1 auto;
  text-align: center;
  font-size: 12px;
  letter-spacing: 0.22em;
  color: var(--haze);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.header-util {
  display: flex;
  align-items: center;
  gap: 18px;
  flex: none;
}

.util-link {
  position: relative;
  display: inline-block;
  padding: 5px 0;
  font-size: 13px;
  letter-spacing: 0.12em;
  color: var(--pale);
  white-space: nowrap;
  transition: color 0.24s var(--ease);
}

.util-link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background: var(--neon);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.3s var(--ease);
}

.util-link:hover { color: var(--paper); }
.util-link:hover::after { transform: scaleX(1); }

.util-link--search {
  color: var(--fluoro);
  padding-inline: 12px;
  border: 1px solid rgba(232, 240, 75, 0.4);
}

.util-link--search::after { display: none; }

.util-link--search:hover {
  background: rgba(232, 240, 75, 0.1);
  color: var(--fluoro);
}

.header-nav {
  position: relative;
  max-width: var(--shell-max);
  margin-inline: auto;
  padding: 0 var(--pad-x);
  min-height: 52px;
  display: flex;
  align-items: center;
}

.site-nav {
  display: flex;
  align-items: center;
  min-width: 0;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: clamp(12px, 2.2vw, 34px);
  flex-wrap: wrap;
}

.nav-link {
  display: inline-flex;
  align-items: baseline;
  gap: 7px;
  padding: 15px 0 13px;
  font-size: 15px;
  letter-spacing: 0.1em;
  color: var(--pale);
  border-bottom: 2px solid transparent;
  transition: color 0.24s var(--ease), border-color 0.24s var(--ease);
}

.nav-link__code {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.16em;
  color: var(--haze);
  transition: color 0.24s var(--ease);
}

.nav-link:hover {
  color: var(--paper);
  border-bottom-color: rgba(255, 90, 60, 0.55);
}

.nav-link[aria-current="page"] {
  color: var(--paper);
  border-bottom-color: var(--neon);
}

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

.nav-toggle {
  display: none;
  align-items: center;
  gap: 12px;
  padding: 14px 0;
  font-size: 13px;
  letter-spacing: 0.2em;
  color: var(--fluoro);
}

.nav-toggle__bars {
  position: relative;
  display: block;
  width: 22px;
  height: 10px;
}

.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 22px;
  height: 2px;
  background: var(--neon);
  transition: transform 0.28s var(--ease);
}

.nav-toggle__bars::before { top: 0; }
.nav-toggle__bars::after { bottom: 0; }

.nav-toggle[aria-expanded="true"] .nav-toggle__bars::before {
  transform: translateY(4px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after {
  transform: translateY(-4px) rotate(-45deg);
}

/* ------------------------------ 页脚 ----------------------------------- */
.site-footer {
  position: relative;
  margin-inline-start: var(--rail-w);
  background: var(--mist);
  border-top: 1px solid var(--edge);
}

.site-footer::before {
  content: "";
  display: block;
  height: 6px;
  background: repeating-linear-gradient(
    90deg,
    var(--clay) 0 16px,
    transparent 16px 32px
  );
  opacity: 0.6;
}

.footer-grid {
  max-width: var(--shell-max);
  margin-inline: auto;
  padding: 56px var(--pad-x) 36px;
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1.3fr;
  gap: clamp(28px, 3.4vw, 52px);
}

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

.footer-brand {
  font-family: var(--font-display);
  font-size: clamp(24px, 2.6vw, 32px);
  font-weight: 300;
  letter-spacing: 0.14em;
  color: var(--paper);
  line-height: 1.2;
}

.footer-line {
  margin-top: 14px;
  max-width: 26ch;
  font-size: 14px;
  line-height: 1.85;
  color: var(--haze);
}

.footer-title {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 400;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--fluoro);
  margin-bottom: 16px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--edge-soft);
}

.footer-list li + li { margin-top: 10px; }

.footer-list a {
  font-size: 15px;
  color: var(--pale);
  border-bottom: 1px solid transparent;
  transition: color 0.22s var(--ease), border-color 0.22s var(--ease);
}

.footer-list a:hover {
  color: var(--neon);
  border-bottom-color: rgba(255, 90, 60, 0.5);
}

.footer-list--contact li {
  font-size: 14px;
  color: var(--pale);
  line-height: 1.7;
  word-break: break-word;
}

.footer-key {
  display: block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--haze);
}

.footer-actions { margin-top: 20px; }

.footer-base {
  max-width: var(--shell-max);
  margin-inline: auto;
  padding: 24px var(--pad-x) 38px;
  border-top: 1px solid var(--edge-soft);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 14px 30px;
}

.footer-note {
  flex: 1 1 340px;
  font-size: 13px;
  line-height: 1.75;
  color: var(--haze);
}

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
}

.footer-legal a {
  font-size: 13px;
  color: var(--haze);
  transition: color 0.22s var(--ease);
}

.footer-legal a:hover { color: var(--paper); }

.footer-icp {
  flex: 1 1 100%;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--haze);
}

/* ------------------------------ 排版层级 -------------------------------- */
.display-xl,
.display-lg,
.display-md {
  font-family: var(--font-display);
  font-weight: 300;
  letter-spacing: 0.08em;
  color: var(--paper);
}

.display-xl {
  font-size: clamp(64px, 12vw, 168px);
  line-height: 0.92;
}

.display-lg {
  font-size: clamp(32px, 4.6vw, 60px);
  line-height: 1.06;
}

.display-md {
  font-size: clamp(20px, 2.2vw, 28px);
  line-height: 1.35;
  color: var(--pale);
}

.index-num {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--fluoro);
}

.data-num {
  font-family: var(--font-mono);
  font-size: 15px;
  letter-spacing: 0.04em;
  color: var(--paper);
  font-variant-numeric: tabular-nums;
}

/* ------------------------------ 正文 / 面包屑 --------------------------- */
.prose {
  max-width: 68ch;
  font-size: 17px;
  line-height: 1.85;
  color: var(--pale);
}

.prose p + p,
.prose p + ul,
.prose ul + p { margin-top: 1.2em; }

.prose h2,
.prose h3 {
  font-family: var(--font-display);
  font-weight: 400;
  letter-spacing: 0.06em;
  color: var(--paper);
  line-height: 1.3;
  margin-top: 2em;
}

.prose h2 { font-size: clamp(24px, 2.6vw, 34px); }
.prose h3 { font-size: clamp(19px, 2vw, 24px); }

.prose a {
  color: var(--fluoro);
  border-bottom: 1px solid rgba(232, 240, 75, 0.42);
}

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

.prose ul {
  list-style: none;
  margin-block: 1.2em;
}

.prose li {
  position: relative;
  padding-left: 1.3em;
}

.prose li + li { margin-top: 0.5em; }

.prose li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.86em;
  width: 8px;
  height: 1px;
  background: var(--clay);
}

.prose--wide { max-width: 82ch; }

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--haze);
}

.breadcrumb li {
  display: inline-flex;
  align-items: center;
}

.breadcrumb li::after {
  content: "/";
  margin-inline: 8px;
  color: rgba(122, 135, 152, 0.55);
}

.breadcrumb li:last-child::after { display: none; }

.breadcrumb a:hover { color: var(--fluoro); }

/* ------------------------------ 网格 ----------------------------------- */
.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(16px, 2vw, 32px);
  align-items: start;
}

.col-main { grid-column: span 7; }
.col-side { grid-column: span 4; }
.col-diag { grid-column: span 1; }
.col-full { grid-column: 1 / -1; }

/* ------------------------------ 按钮 ----------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 13px 26px;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.14em;
  line-height: 1.2;
  color: var(--rock);
  background: var(--neon);
  border: 1px solid var(--neon);
  transition: transform 0.25s var(--ease), background 0.25s var(--ease),
    color 0.25s var(--ease), border-color 0.25s var(--ease);
}

.btn:hover {
  transform: translateY(-2px);
  background: #ff7256;
  border-color: #ff7256;
}

.btn:active { transform: translateY(0); }

.btn--ghost {
  background: transparent;
  color: var(--neon);
}

.btn--ghost:hover {
  background: rgba(255, 90, 60, 0.13);
  color: var(--fluorine, #ff8a72);
  border-color: var(--neon);
}

.btn--quiet {
  background: transparent;
  color: var(--pale);
  border-color: rgba(122, 135, 152, 0.45);
  font-weight: 400;
}

.btn--quiet:hover {
  background: transparent;
  border-color: var(--fluoro);
  color: var(--fluoro);
}

/* ------------------------------ 章节标题 -------------------------------- */
.section-head {
  position: relative;
  margin-bottom: clamp(24px, 3.2vw, 44px);
  padding-top: 20px;
}

.section-head::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 56px;
  height: 2px;
  background: var(--neon);
}

.section-index {
  display: block;
  margin-bottom: 10px;
}

.section-title {
  font-family: var(--font-display);
  font-weight: 300;
  font-size: clamp(32px, 4.6vw, 60px);
  line-height: 1.06;
  letter-spacing: 0.08em;
  color: var(--paper);
}

.section-sub {
  display: block;
  margin-top: 12px;
  font-size: clamp(20px, 2.2vw, 28px);
  font-weight: 300;
  letter-spacing: 0.05em;
  color: var(--haze);
}

/* ------------------------------ 标签 / 卡片 ----------------------------- */
.coord-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 4px 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--clay);
  background: rgba(184, 97, 63, 0.1);
  border: 1px solid rgba(184, 97, 63, 0.5);
}

.coord-tag--river {
  color: var(--river);
  background: rgba(47, 143, 124, 0.1);
  border-color: rgba(47, 143, 124, 0.5);
}

.card {
  position: relative;
  padding: clamp(20px, 2.4vw, 30px);
  background: var(--mist);
  border: 1px solid var(--edge);
  transition: transform 0.3s var(--ease), border-color 0.3s var(--ease);
}

.card::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 20px;
  height: 20px;
  background: linear-gradient(225deg, var(--rock) 50%, transparent 50%);
  transition: width 0.3s var(--ease), height 0.3s var(--ease);
}

.card:hover {
  transform: translateY(-3px);
  border-color: var(--clay);
}

.card:hover::after {
  width: 28px;
  height: 28px;
}

.card--lift { margin-top: 24px; }

/* ------------------------------ 影像容器 -------------------------------- */
.media-frame {
  position: relative;
  overflow: hidden;
  width: 100%;
  aspect-ratio: 16 / 10;
  background:
    linear-gradient(135deg, rgba(47, 143, 124, 0.2), rgba(18, 22, 28, 0.92)),
    var(--rock);
  border: 1px solid var(--edge);
}

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

.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(180deg, transparent 52%, rgba(18, 22, 28, 0.68));
}

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

/* ------------------------------ 分段切换 -------------------------------- */
.segmented {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.segmented__input {
  position: absolute;
  width: 1px;
  height: 1px;
  opacity: 0;
  pointer-events: none;
}

.segmented__label {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 18px;
  font-size: 14px;
  letter-spacing: 0.12em;
  color: var(--pale);
  background: rgba(42, 53, 66, 0.6);
  border: 1px solid rgba(122, 135, 152, 0.35);
  cursor: pointer;
  transition: color 0.24s var(--ease), background 0.24s var(--ease),
    border-color 0.24s var(--ease);
}

.segmented__label:hover {
  color: var(--paper);
  border-color: var(--clay);
}

.segmented__input:checked + .segmented__label {
  color: var(--rock);
  background: var(--neon);
  border-color: var(--neon);
  font-weight: 600;
}

.segmented__input:focus-visible + .segmented__label {
  outline: 2px solid var(--fluoro);
  outline-offset: 2px;
}

/* ------------------------------ 折叠说明 -------------------------------- */
.fold {
  background: rgba(42, 53, 66, 0.62);
  border: 1px solid var(--edge);
  margin-bottom: 12px;
}

.fold__q {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 16px 20px;
  font-size: 16px;
  color: var(--paper);
  cursor: pointer;
  list-style: none;
  transition: color 0.22s var(--ease);
}

.fold__q::-webkit-details-marker { display: none; }

.fold__q::before {
  content: "+";
  flex: none;
  font-family: var(--font-mono);
  font-size: 18px;
  line-height: 1.5;
  color: var(--neon);
  transition: transform 0.26s var(--ease);
}

.fold[open] .fold__q::before { transform: rotate(45deg); }
.fold__q:hover { color: var(--fluoro); }

.fold__a {
  padding: 0 20px 20px 54px;
  font-size: 16px;
  line-height: 1.85;
  color: var(--pale);
}

/* ------------------------------ 数据表 ---------------------------------- */
.data-table {
  width: 100%;
  font-size: 15px;
}

.data-table th,
.data-table td {
  text-align: left;
  padding: 14px 16px;
  border-bottom: 1px solid var(--edge-soft);
  vertical-align: top;
}

.data-table th {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 400;
  letter-spacing: 0.18em;
  color: var(--fluoro);
  background: rgba(76, 107, 78, 0.16);
}

.data-table td { color: var(--pale); }

.data-table td.num,
.data-table td .num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  color: var(--paper);
}

.data-table tbody tr:hover {
  background: rgba(122, 135, 152, 0.07);
}

/* ------------------------------ 时间线 ---------------------------------- */
.timeline {
  display: flex;
  border-top: 1px solid var(--edge);
  overflow-x: auto;
  scroll-snap-type: x proximity;
}

.timeline__node {
  position: relative;
  flex: 1 0 180px;
  padding: 22px 18px 26px;
  scroll-snap-align: start;
  background: linear-gradient(180deg, rgba(76, 107, 78, 0.2), transparent 70%);
  border-inline-end: 1px solid var(--edge-soft);
}

.timeline__node::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  width: 100%;
  height: 2px;
  background: var(--clay);
}

.timeline__stage {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--fluoro);
}

/* ------------------------------ 显现动画 -------------------------------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 0.46s var(--ease), transform 0.46s var(--ease);
}

[data-reveal="on"] {
  opacity: 1;
  transform: none;
}

/* ------------------------------ 响应式 ---------------------------------- */
@media (max-width: 1120px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }

  .footer-icp { flex-basis: 100%; }
}

@media (max-width: 960px) {
  :root { --rail-w: 0px; }

  .rail { display: none; }

  .site-header,
  .site-footer,
  .page-main { margin-inline-start: 0; }

  .header-tagline { display: none; }

  .grid-12 { grid-template-columns: repeat(6, minmax(0, 1fr)); }

  .col-main { grid-column: span 6; }
  .col-side { grid-column: span 6; }
  .col-diag { display: none; }
}

@media (max-width: 860px) {
  html { scroll-padding-top: 96px; }

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

  .header-nav { justify-content: flex-start; }

  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    display: block;
    padding: 0 var(--pad-x);
    max-height: 0;
    overflow: hidden;
    visibility: hidden;
    background: linear-gradient(180deg, var(--mist) 0%, var(--rock) 100%);
    border-bottom: 1px solid var(--edge);
    transition: max-height 0.38s var(--ease), visibility 0.38s var(--ease);
  }

  .site-nav[data-open="true"] {
    max-height: min(72vh, 560px);
    overflow-y: auto;
    visibility: visible;
    padding-bottom: 26px;
  }

  .nav-list {
    display: block;
    padding-top: 10px;
  }

  .nav-list li { border-bottom: 1px solid var(--edge-soft); }

  .nav-link {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 18px 0;
    font-size: 18px;
    letter-spacing: 0.06em;
    border-bottom: 0;
  }

  .nav-link__code { order: 2; }

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

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

  .header-top__inner { flex-wrap: wrap; gap: 8px 16px; }
  .header-util { gap: 12px; }

  .footer-grid {
    grid-template-columns: 1fr;
    padding-top: 44px;
  }

  .footer-line { max-width: none; }
}

@media (max-width: 640px) {
  body { font-size: 16px; }

  .brand__coord { display: none; }

  .util-link { font-size: 12px; letter-spacing: 0.08em; }

  .footer-base { flex-direction: column; align-items: flex-start; }

  .data-table thead { display: none; }

  .data-table tr {
    display: block;
    margin-bottom: 14px;
    padding: 4px 0;
    background: rgba(42, 53, 66, 0.55);
    border: 1px solid var(--edge);
  }

  .data-table td {
    display: flex;
    justify-content: space-between;
    gap: 18px;
    border-bottom: 1px dashed var(--edge-soft);
  }

  .data-table td:last-child { border-bottom: 0; }

  .data-table td::before {
    content: attr(data-label);
    flex: none;
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: 0.14em;
    color: var(--haze);
  }
}

/* ------------------------------ 降级动效 -------------------------------- */
@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] {
    opacity: 1;
    transform: none;
  }
}