:root {
  --night: #0B1E2D;
  --night-deep: #08161f;
  --panel: #102A3A;
  --panel-soft: #0E2534;
  --mist: #E7EDE8;
  --chalk: #F4F7F3;
  --cyan: #00E5C3;
  --orange: #FF6B35;
  --grass: #1F7A5C;
  --yellow: #F5D547;
  --steel: #8FA6B2;
  --teal-shadow: #073B3A;
  --line: rgba(143, 166, 178, .22);
  --line-strong: rgba(143, 166, 178, .44);
  --rail-w: 100px;
  --shell: 1360px;
  --gutter: clamp(20px, 5vw, 64px);
  --radius: 24px;
  --radius-sm: 12px;
  --header-h: 64px;
  --progress: 0%;
  --font-head: "HarmonyOS Sans SC", "Source Han Sans SC", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-body: "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --font-mono: ui-monospace, "JetBrains Mono", "Roboto Mono", "SFMono-Regular", Menlo, Consolas, monospace;
  --ease: cubic-bezier(.22, .68, 0, 1);
}

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

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

body,
h1, h2, h3, h4, h5, p, ul, ol, figure, blockquote, fieldset {
  margin: 0;
}

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

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

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

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

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

body {
  position: relative;
  min-height: 100vh;
  padding-top: var(--header-h);
  background:
    radial-gradient(900px 620px at 82% -12%, rgba(0, 229, 195, .10), transparent 62%),
    radial-gradient(760px 520px at 6% 38%, rgba(255, 107, 53, .09), transparent 66%),
    radial-gradient(700px 700px at 52% 108%, rgba(31, 122, 92, .16), transparent 70%),
    var(--night);
  color: var(--chalk);
  font-family: var(--font-body);
  font-size: clamp(16px, .35vw + 15px, 18px);
  line-height: 1.65;
  letter-spacing: .01em;
  -webkit-font-smoothing: antialiased;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(143, 166, 178, .07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(143, 166, 178, .07) 1px, transparent 1px);
  background-size: 64px 64px;
  -webkit-mask-image: radial-gradient(circle at 46% 24%, #000 18%, transparent 78%);
  mask-image: radial-gradient(circle at 46% 24%, #000 18%, transparent 78%);
  opacity: .55;
}

h1, h2, h3, h4 {
  font-family: var(--font-head);
  font-weight: 800;
  line-height: 1.08;
  letter-spacing: -.02em;
  color: var(--chalk);
}

h1 { font-size: clamp(44px, 7vw, 112px); }
h2 { font-size: clamp(28px, 4vw, 56px); }
h3 { font-size: clamp(20px, 1.6vw, 27px); }
h4 { font-size: clamp(17px, 1.2vw, 20px); }

strong { color: var(--cyan); font-weight: 700; }

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

/* ---------- skip link ---------- */
.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 200;
  padding: 10px 18px;
  border-radius: 999px;
  background: var(--cyan);
  color: var(--night);
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .06em;
  transform: translateY(-180%);
  transition: transform .26s var(--ease);
}

.skip-link:focus,
.skip-link:focus-visible {
  transform: translateY(0);
  outline-offset: 4px;
}

/* ---------- header shell ---------- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 60;
  display: flex;
  align-items: center;
  gap: 12px;
  height: var(--header-h);
  padding: 0 clamp(16px, 4vw, 24px);
  background: linear-gradient(180deg, rgba(16, 42, 58, .97), rgba(11, 30, 45, .94));
  border-bottom: 1px solid var(--line);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
}

.site-header::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 65;
  background: rgba(5, 14, 20, .68);
  -webkit-backdrop-filter: blur(2px);
  backdrop-filter: blur(2px);
  opacity: 0;
  pointer-events: none;
  transition: opacity .3s var(--ease);
}

.site-header[data-open="true"]::after {
  opacity: 1;
  pointer-events: auto;
}

/* ---------- brand ---------- */
.brand-slot {
  display: flex;
  align-items: center;
  gap: 12px;
  flex: 1 1 auto;
  min-width: 0;
}

.brand {
  display: flex;
  align-items: center;
  gap: 11px;
  min-width: 0;
}

.brand-mark {
  position: relative;
  flex: none;
  width: 30px;
  height: 30px;
  border-radius: 9px;
  background: conic-gradient(from 205deg, var(--cyan), var(--teal-shadow) 58%, var(--orange));
  box-shadow: inset 0 0 0 1px rgba(11, 30, 45, .55);
}

.brand-mark::before {
  content: "";
  position: absolute;
  inset: 8px;
  border: 2px solid var(--night);
  border-right-color: transparent;
  border-radius: 3px;
}

.brand-mark::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 50%;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--yellow);
  transform: translate(-50%, -50%);
}

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

.brand-name {
  font-family: var(--font-head);
  font-weight: 800;
  font-size: 18px;
  letter-spacing: .06em;
  line-height: 1.2;
  color: var(--chalk);
  white-space: nowrap;
}

.brand-descriptor {
  margin-top: 2px;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: .12em;
  color: var(--steel);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.header-status { display: none; }

.status-dot {
  flex: none;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 0 3px rgba(0, 229, 195, .16);
}

/* ---------- navigation ---------- */
.site-nav {
  position: fixed;
  top: var(--header-h);
  right: 0;
  bottom: 0;
  z-index: 70;
  display: flex;
  flex-direction: column;
  gap: 10px;
  width: min(86vw, 360px);
  padding: 22px 20px calc(26px + env(safe-area-inset-bottom));
  background: linear-gradient(165deg, var(--panel), var(--night-deep));
  border-left: 1px solid var(--line);
  box-shadow: -30px 0 60px -30px #000;
  transform: translateX(104%);
  visibility: hidden;
  transition: transform .4s var(--ease), visibility .4s var(--ease);
  overflow-y: auto;
}

.site-header[data-open="true"] .site-nav {
  transform: translateX(0);
  visibility: visible;
}

.nav-list {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.rail-link {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 13px 14px;
  border-radius: 14px;
  border: 1px solid transparent;
  color: var(--chalk);
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 19px;
  letter-spacing: .02em;
  transition: background .25s var(--ease), border-color .25s var(--ease), color .25s var(--ease);
}

.rail-index {
  flex: none;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 400;
  letter-spacing: .12em;
  color: var(--steel);
  font-variant-numeric: tabular-nums;
}

.rail-label { min-width: 0; }

.rail-link:hover {
  background: rgba(0, 229, 195, .08);
  border-color: rgba(0, 229, 195, .24);
}

.rail-link[aria-current="page"] {
  background: rgba(0, 229, 195, .13);
  border-color: rgba(0, 229, 195, .5);
  color: var(--cyan);
}

.rail-link[aria-current="page"] .rail-index { color: var(--cyan); }

.rail-link[aria-current="page"]::after {
  content: "";
  width: 7px;
  height: 7px;
  margin-left: auto;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 0 4px rgba(0, 229, 195, .16);
}

.rail-cta {
  display: flex;
  align-items: center;
  justify-content: center;
  margin-top: auto;
  padding: 15px 14px;
  border-radius: 999px;
  background: var(--cyan);
  color: var(--night);
  font-family: var(--font-head);
  font-weight: 800;
  font-size: 15px;
  letter-spacing: .04em;
  text-align: center;
  box-shadow: 0 16px 34px -20px rgba(0, 229, 195, .95);
  transition: transform .2s var(--ease), background .2s var(--ease);
}

.rail-cta:hover { transform: translateY(-2px); background: #3cf5d8; }

.rail-note {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--steel);
  text-align: center;
}

/* ---------- nav toggle ---------- */
.nav-toggle {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  flex: none;
  padding: 10px 15px;
  border-radius: 999px;
  border: 1px solid var(--line-strong);
  background: rgba(0, 229, 195, .07);
  color: var(--chalk);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  transition: border-color .22s var(--ease), background .22s var(--ease);
}

.nav-toggle:hover { border-color: var(--cyan); }

.nav-toggle-bars {
  position: relative;
  flex: none;
  width: 18px;
  height: 10px;
}

.nav-toggle-bars::before,
.nav-toggle-bars::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  height: 2px;
  border-radius: 2px;
  background: var(--cyan);
  transition: transform .3s var(--ease), top .3s var(--ease);
}

.nav-toggle-bars::before { top: 0; }
.nav-toggle-bars::after { top: 8px; }

.site-header[data-open="true"] .nav-toggle-bars::before { transform: translateY(4px) rotate(45deg); }
.site-header[data-open="true"] .nav-toggle-bars::after { transform: translateY(-4px) rotate(-45deg); }

/* ---------- reading progress ---------- */
.read-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background: rgba(143, 166, 178, .18);
  overflow: hidden;
}

.read-progress-bar {
  display: block;
  width: var(--progress, 0%);
  height: 100%;
  background: linear-gradient(90deg, var(--cyan), var(--yellow));
  transition: width .12s linear;
}

/* ---------- footer ---------- */
.site-footer {
  position: relative;
  z-index: 1;
  margin-top: clamp(64px, 9vw, 140px);
  padding: clamp(38px, 5.5vw, 78px) var(--gutter) 0;
  background:
    radial-gradient(720px 380px at 88% 0%, rgba(0, 229, 195, .13), transparent 62%),
    radial-gradient(560px 420px at 4% 100%, rgba(31, 122, 92, .22), transparent 70%),
    linear-gradient(180deg, rgba(16, 42, 58, .78), var(--night-deep) 62%);
  border-top: 1px solid var(--line);
  overflow: hidden;
}

.site-footer::before {
  content: "";
  position: absolute;
  inset: 0 0 auto;
  height: 6px;
  background: repeating-linear-gradient(115deg, var(--cyan) 0 16px, transparent 16px 34px);
  opacity: .45;
}

.footer-scan {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px 18px;
  padding-bottom: clamp(22px, 3vw, 40px);
  border-bottom: 1px dashed var(--line-strong);
}

.footer-scan-label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .2em;
  color: var(--steel);
  text-transform: uppercase;
}

.footer-scan-value {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .08em;
  color: var(--yellow);
  font-variant-numeric: tabular-nums;
  margin-right: clamp(10px, 3vw, 32px);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(28px, 4vw, 54px);
  padding: clamp(30px, 4.5vw, 62px) 0;
}

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

.footer-col--support {
  position: relative;
  padding-left: 18px;
}

.footer-col--support::before {
  content: "";
  position: absolute;
  left: 0;
  top: 6px;
  bottom: 6px;
  width: 3px;
  border-radius: 3px;
  background: linear-gradient(180deg, var(--orange), rgba(255, 107, 53, 0));
}

.footer-brand {
  display: inline-block;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(26px, 3.4vw, 38px);
  letter-spacing: -.01em;
  color: var(--chalk);
}

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

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

.footer-address {
  margin-top: 16px;
  font-size: 14px;
  line-height: 1.75;
  color: var(--steel);
  max-width: 36ch;
}

.footer-title {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--yellow);
}

.footer-title::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--line);
}

.footer-list {
  display: flex;
  flex-direction: column;
  gap: 1px;
}

.footer-link {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 7px 0;
  font-size: 15px;
  color: var(--chalk);
  transition: color .2s var(--ease), gap .2s var(--ease);
}

.footer-link::before {
  content: "";
  flex: none;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--line-strong);
  transition: background .2s var(--ease);
}

.footer-link:hover { color: var(--cyan); gap: 12px; }
.footer-link:hover::before { background: var(--cyan); }

.footer-link[aria-current="page"] {
  color: var(--cyan);
  font-weight: 700;
}

.footer-link[aria-current="page"]::before { background: var(--cyan); }

.footer-note {
  padding: 5px 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--steel);
}

.copy-chip {
  display: inline-block;
  max-width: 100%;
  margin: 4px 0 10px;
  padding: 7px 14px;
  border-radius: 999px;
  border: 1px solid var(--line-strong);
  background: rgba(0, 229, 195, .07);
  color: var(--cyan);
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .03em;
  text-align: left;
  word-break: break-all;
  transition: background .2s var(--ease), border-color .2s var(--ease), color .2s var(--ease);
}

.copy-chip:hover {
  background: rgba(0, 229, 195, .16);
  border-color: var(--cyan);
}

.copy-chip[data-copied="true"] {
  background: var(--cyan);
  border-color: var(--cyan);
  color: var(--night);
  font-weight: 700;
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 22px;
  padding: 20px 0 28px;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--steel);
}

.footer-legal,
.footer-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px 18px;
  font-variant-numeric: tabular-nums;
}

/* ---------- shared layout ---------- */
.wrap {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

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

.stack {
  display: flex;
  flex-direction: column;
  gap: clamp(24px, 4vw, 56px);
}

.split {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 4vw, 56px);
}

.grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(16px, 2.4vw, 28px);
}

.divider-cut {
  height: 1px;
  border: 0;
  margin: clamp(30px, 5vw, 70px) 0;
  background: linear-gradient(90deg, transparent, var(--line-strong), transparent);
}

/* ---------- shared type ---------- */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .24em;
  text-transform: uppercase;
  color: var(--cyan);
}

.eyebrow::before {
  content: "";
  width: 22px;
  height: 1px;
  background: var(--cyan);
}

.lede {
  max-width: 58ch;
  font-size: clamp(17px, 1.5vw, 21px);
  line-height: 1.7;
  color: rgba(244, 247, 243, .84);
}

.mono {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: .04em;
}

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: 14px 24px;
  margin-bottom: clamp(20px, 3vw, 36px);
}

.section-index {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .22em;
  color: var(--yellow);
  font-variant-numeric: tabular-nums;
}

.section-title {
  font-size: clamp(28px, 4vw, 56px);
}

.section-note {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--steel);
  text-align: right;
}

/* ---------- breadcrumb ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding-top: clamp(20px, 3vw, 36px);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--steel);
}

.crumb {
  color: var(--steel);
  transition: color .2s var(--ease);
}

a.crumb:hover { color: var(--cyan); }

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

.crumb-sep { color: rgba(143, 166, 178, .5); }

/* ---------- buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 14px 26px;
  border-radius: 999px;
  border: 1px solid transparent;
  font-family: var(--font-head);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: .02em;
  cursor: pointer;
  transition: transform .2s var(--ease), background .2s var(--ease), border-color .2s var(--ease), color .2s var(--ease);
}

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

.btn--cyan {
  background: var(--cyan);
  color: var(--night);
  box-shadow: 0 16px 34px -20px rgba(0, 229, 195, .95);
}

.btn--orange {
  background: var(--orange);
  color: var(--night);
  box-shadow: 0 16px 34px -22px rgba(255, 107, 53, .95);
}

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

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

.btn--block { width: 100%; }

/* ---------- tags ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 11px;
  border-radius: 999px;
  border: 1px solid transparent;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .1em;
  white-space: nowrap;
}

.tag--cyan {
  background: rgba(0, 229, 195, .14);
  border-color: rgba(0, 229, 195, .42);
  color: var(--cyan);
}

.tag--orange {
  background: rgba(255, 107, 53, .16);
  border-color: rgba(255, 107, 53, .5);
  color: #FFB79C;
}

.tag--yellow {
  background: rgba(245, 213, 71, .16);
  border-color: rgba(245, 213, 71, .48);
  color: var(--yellow);
}

.tag--grass {
  background: rgba(31, 122, 92, .32);
  border-color: rgba(31, 122, 92, .78);
  color: #93E4C6;
}

/* ---------- panels ---------- */
.panel {
  position: relative;
  padding: clamp(22px, 3vw, 40px);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(165deg, rgba(16, 42, 58, .96), rgba(11, 30, 45, .92));
  box-shadow: 0 34px 64px -46px #000;
}

.panel--light {
  background: linear-gradient(170deg, var(--mist), #d8e2da);
  border-color: rgba(11, 30, 45, .14);
  color: var(--night);
}

.panel--light h2,
.panel--light h3,
.panel--light h4 { color: var(--night); }

.panel--light .lede { color: rgba(11, 30, 45, .78); }

.panel--cut {
  border-radius: var(--radius) var(--radius) 8px var(--radius);
  overflow: hidden;
}

.panel--cut::after {
  content: "";
  position: absolute;
  right: 0;
  bottom: 0;
  width: 46px;
  height: 46px;
  background: linear-gradient(135deg, transparent 50%, var(--cyan) 50%);
  opacity: .9;
  pointer-events: none;
}

/* ---------- media frame ---------- */
.media-frame {
  position: relative;
  overflow: hidden;
  margin: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  aspect-ratio: 16 / 10;
  background:
    radial-gradient(120% 90% at 18% 8%, rgba(0, 229, 195, .30), transparent 56%),
    radial-gradient(100% 80% at 86% 92%, rgba(255, 107, 53, .30), transparent 62%),
    linear-gradient(160deg, #0E2534, #08161f);
}

.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(244, 247, 243, .09) 1px, transparent 1px),
    linear-gradient(90deg, rgba(244, 247, 243, .09) 1px, transparent 1px);
  background-size: 40px 40px;
  opacity: .5;
}

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

.media-frame figcaption {
  position: absolute;
  left: 14px;
  bottom: 12px;
  z-index: 2;
  padding: 5px 11px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: rgba(8, 22, 31, .74);
  color: var(--chalk);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .08em;
}

.media-frame--wide { aspect-ratio: 16 / 9; }
.media-frame--tall { aspect-ratio: 3 / 4; }
.media-frame--square { aspect-ratio: 1 / 1; }

/* ---------- reveal ---------- */
.reveal {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity .6s var(--ease), transform .6s var(--ease);
}

.reveal.is-in {
  opacity: 1;
  transform: none;
}

/* ---------- responsive ---------- */
@media (max-width: 420px) {
  .brand-descriptor { display: none; }
}

@media (min-width: 720px) {
  .footer-grid { grid-template-columns: 1.15fr .9fr 1.15fr; }
  .grid--2 { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 900px) {
  .split { grid-template-columns: 1.25fr .85fr; align-items: start; }
  .grid--3 { grid-template-columns: repeat(3, 1fr); }
}

@media (min-width: 1024px) {
  body { padding-top: 0; padding-left: var(--rail-w); }

  .site-header {
    right: auto;
    bottom: 0;
    width: var(--rail-w);
    height: 100vh;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 22px 0 16px;
    border-right: 1px solid var(--line);
    border-bottom: 0;
    background: linear-gradient(180deg, var(--panel) 0%, var(--night) 56%, var(--teal-shadow) 100%);
    overflow-y: auto;
    overflow-x: hidden;
    scrollbar-width: none;
  }

  .site-header::-webkit-scrollbar { display: none; }

  .site-header::after { display: none; }

  .brand-slot {
    flex: none;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    padding: 0 8px 16px;
    border-bottom: 1px dashed var(--line);
  }

  .brand {
    flex-direction: column;
    gap: 10px;
    align-items: center;
  }

  .brand-text { align-items: center; }

  .brand-name {
    writing-mode: vertical-rl;
    font-size: 17px;
    letter-spacing: .28em;
    line-height: 1;
  }

  .brand-descriptor { display: none; }

  .header-status {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
    padding: 0 6px;
    font-family: var(--font-mono);
    font-size: 10px;
    line-height: 1.4;
    letter-spacing: .06em;
    color: var(--steel);
    text-align: center;
  }

  .site-nav {
    position: static;
    flex: 1 1 auto;
    width: 100%;
    min-height: 0;
    align-items: center;
    gap: 0;
    padding: 14px 8px 8px;
    background: none;
    border-left: 0;
    box-shadow: none;
    transform: none;
    visibility: visible;
    overflow-y: auto;
    scrollbar-width: none;
  }

  .site-nav::-webkit-scrollbar { display: none; }

  .nav-list {
    width: 100%;
    align-items: center;
    gap: 2px;
  }

  .rail-link {
    flex-direction: column;
    justify-content: center;
    gap: 7px;
    width: 100%;
    padding: 9px 2px;
    border-radius: 12px;
    font-size: 12px;
    letter-spacing: .05em;
    line-height: 1.2;
  }

  .rail-index {
    font-size: 10px;
    letter-spacing: .14em;
  }

  .rail-label {
    writing-mode: vertical-rl;
    letter-spacing: .12em;
    font-weight: 700;
  }

  .rail-link[aria-current="page"]::after { display: none; }

  .rail-link[aria-current="page"] {
    box-shadow: inset 0 0 0 1px rgba(0, 229, 195, .38);
  }

  .rail-cta {
    flex: none;
    margin: 12px 8px 0;
    width: calc(100% - 16px);
    padding: 13px 6px;
    font-size: 12.5px;
    letter-spacing: .02em;
  }

  .rail-note {
    margin-top: 10px;
    font-size: 10px;
    letter-spacing: .04em;
  }

  .nav-toggle { display: none; }

  .read-progress {
    left: auto;
    top: 0;
    right: 0;
    bottom: 0;
    width: 3px;
    height: 100%;
  }

  .read-progress-bar {
    width: 100%;
    height: var(--progress, 0%);
    background: linear-gradient(180deg, var(--cyan), var(--orange));
    transition: height .12s linear;
  }

  .section-note { text-align: right; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

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

  .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .btn:hover,
  .rail-cta:hover { transform: none; }
}