:root {
  --space-void: #0A0F2C;
  --nebula: #3B1E6E;
  --silver: #C9D2E3;
  --neon: #39E6F2;
  --gold: #FFB84D;
  --portal-blue: #1B3A8C;
  --event-violet: #7A4DFF;
  --download: #4CD9A0;
  --alert: #FF5EA8;
  --white: #FFFFFF;

  --ink-90: rgba(201, 210, 227, 0.92);
  --ink-70: rgba(201, 210, 227, 0.72);
  --ink-50: rgba(201, 210, 227, 0.5);
  --line: rgba(201, 210, 227, 0.16);
  --line-strong: rgba(57, 230, 242, 0.42);
  --panel: rgba(255, 255, 255, 0.035);

  --radius-xl: 32px;
  --radius-lg: 24px;
  --radius-md: 16px;
  --radius-pill: 999px;

  --shell: min(1240px, calc(100% - 48px));
  --header-h: 76px;
  --shadow-hover: 0 18px 48px rgba(4, 7, 22, 0.6);

  --font-head: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", -apple-system, "Segoe UI", system-ui, sans-serif;
  --font-body: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Segoe UI", Roboto, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
}

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

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

body {
  margin: 0;
  min-height: 100%;
  color: var(--silver);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.85;
  letter-spacing: 0.01em;
  background-color: var(--space-void);
  background-image:
    radial-gradient(900px 620px at 84% -10%, rgba(122, 77, 255, 0.32), transparent 62%),
    radial-gradient(720px 520px at 2% 10%, rgba(57, 230, 242, 0.14), transparent 60%),
    radial-gradient(1100px 820px at 50% 118%, rgba(59, 30, 110, 0.55), transparent 66%),
    linear-gradient(180deg, #0A0F2C 0%, #080C24 42%, #0A0F2C 100%);
  background-repeat: no-repeat;
  background-attachment: fixed;
}

body,
h1, h2, h3, h4, p, ul, ol, dl, dd, figure, blockquote { margin: 0; }
ul, ol { padding: 0; list-style: none; }
a { color: inherit; text-decoration: none; }
img, svg, video { max-width: 100%; display: block; }
button { font: inherit; color: inherit; background: none; border: 0; }
input, select, textarea { font: inherit; }

h1, h2, h3, h4 {
  font-family: var(--font-head);
  font-weight: 800;
  line-height: 1.22;
  letter-spacing: 0.02em;
  color: var(--white);
}
h1 { font-size: clamp(34px, 5.2vw, 64px); }
h2 { font-size: clamp(26px, 3.4vw, 42px); }
h3 { font-size: clamp(20px, 2.2vw, 27px); }

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

::selection { background: rgba(57, 230, 242, 0.28); color: var(--white); }

::-webkit-scrollbar { width: 10px; }
::-webkit-scrollbar-track { background: #070B1F; }
::-webkit-scrollbar-thumb {
  border-radius: 10px;
  background: linear-gradient(180deg, var(--portal-blue), var(--nebula));
}

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

#main-content {
  display: block;
  padding-top: var(--header-h);
}
body[data-hero="overlay"] #main-content { padding-top: 0; }

:where(section, [id]) { scroll-margin-top: calc(var(--header-h) + 28px); }

.shell {
  width: var(--shell);
  margin-inline: auto;
}

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

.skip-link {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 140;
  padding: 12px 22px;
  border-radius: var(--radius-pill);
  background: var(--gold);
  color: #1A1206;
  font-weight: 700;
  transform: translateY(-220%);
  transition: transform 0.25s ease;
}
.skip-link:focus { transform: translateY(0); }

/* ---------- 页头 ---------- */
.site-header {
  position: fixed;
  top: 0;
  right: 0;
  left: 0;
  z-index: 90;
  border-bottom: 1px solid transparent;
  background: linear-gradient(180deg, rgba(10, 15, 44, 0.88), rgba(10, 15, 44, 0));
  transition: background 0.4s ease, border-color 0.4s ease, box-shadow 0.4s ease;
}
.site-header[data-scrolled] {
  background: rgba(9, 13, 36, 0.95);
  border-bottom-color: var(--line);
  box-shadow: 0 18px 40px rgba(4, 7, 22, 0.55);
  backdrop-filter: blur(14px);
}
.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  width: var(--shell);
  min-height: var(--header-h);
  margin-inline: auto;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
}
.brand__mark {
  position: relative;
  display: inline-flex;
  flex: none;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  border-radius: 50%;
  border: 1px solid rgba(57, 230, 242, 0.45);
  background: radial-gradient(circle at 50% 50%, rgba(57, 230, 242, 0.22), rgba(10, 15, 44, 0) 70%);
}
.brand__ring {
  position: absolute;
  inset: 4px;
  border-radius: 50%;
  border: 1px dashed rgba(201, 210, 227, 0.45);
}
.brand__core {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--gold);
  box-shadow: 0 0 16px rgba(255, 184, 77, 0.85);
}
.brand__text {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
}
.brand__name {
  font-family: var(--font-head);
  font-size: 17px;
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: 0.06em;
  color: var(--white);
}
.brand__tagline {
  overflow: hidden;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--ink-50);
  white-space: nowrap;
  text-overflow: ellipsis;
}

.nav-track { display: block; }
.nav-track__list {
  display: flex;
  align-items: center;
  gap: 2px;
}
.nav-track__item { display: block; }
.nav-track__link {
  display: block;
  padding: 9px 11px;
  border-radius: var(--radius-pill);
  font-size: 13.5px;
  letter-spacing: 0.02em;
  color: var(--ink-70);
  white-space: nowrap;
  transition: color 0.25s ease, background 0.25s ease, box-shadow 0.25s ease;
}
.nav-track__link:hover {
  color: var(--white);
  background: rgba(201, 210, 227, 0.08);
}
.nav-track__link[aria-current="page"] {
  color: var(--neon);
  background: rgba(57, 230, 242, 0.1);
  box-shadow: inset 0 0 0 1px rgba(57, 230, 242, 0.35);
}

.header-actions {
  display: flex;
  flex: none;
  align-items: center;
  gap: 10px;
}
.lang-chip {
  padding: 6px 12px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.1em;
  color: var(--ink-70);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: var(--radius-pill);
  border: 1px solid transparent;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.02em;
  cursor: pointer;
  transition: transform 0.25s ease, box-shadow 0.25s ease, background 0.25s ease, color 0.25s ease, border-color 0.25s ease;
}
.btn--gold {
  background: linear-gradient(135deg, var(--gold), #FF9A3C);
  color: #1A1206;
  box-shadow: 0 10px 26px rgba(255, 184, 77, 0.22);
}
.btn--gold:hover {
  transform: translateY(-2px);
  box-shadow: 0 14px 32px rgba(255, 184, 77, 0.34);
}
.btn--ghost {
  border-color: var(--line-strong);
  background: rgba(57, 230, 242, 0.06);
  color: var(--neon);
}
.btn--ghost:hover { background: rgba(57, 230, 242, 0.14); }
.btn--block { width: 100%; }
.btn--compact { padding: 9px 16px; font-size: 13.5px; }

.nav-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.03);
  cursor: pointer;
  transition: border-color 0.25s ease, background 0.25s ease;
}
.nav-toggle:hover { border-color: rgba(57, 230, 242, 0.5); }
.nav-toggle__box {
  position: relative;
  display: block;
  width: 20px;
  height: 12px;
}
.nav-toggle__box::before,
.nav-toggle__box::after {
  content: "";
  position: absolute;
  right: 0;
  left: 0;
  height: 1.6px;
  border-radius: 2px;
  background: var(--silver);
  transition: transform 0.3s ease, top 0.3s ease, background 0.3s ease;
}
.nav-toggle__box::before { top: 0; }
.nav-toggle__box::after { top: 10px; }
.nav-toggle[aria-expanded="true"] .nav-toggle__box::before {
  top: 5px;
  background: var(--neon);
  transform: rotate(45deg);
}
.nav-toggle[aria-expanded="true"] .nav-toggle__box::after {
  top: 5px;
  background: var(--neon);
  transform: rotate(-45deg);
}

.portal-progress {
  position: absolute;
  right: 0;
  bottom: 0;
  left: 0;
  height: 2px;
  background: rgba(201, 210, 227, 0.1);
}
.portal-progress__bar {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--neon), var(--gold));
}

/* ---------- 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: 96px;
  overflow: hidden;
  border-top: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(10, 15, 44, 0.4), rgba(5, 8, 22, 0.98) 58%);
}
.site-footer__glow {
  position: absolute;
  top: -180px;
  left: 50%;
  width: 680px;
  height: 340px;
  transform: translateX(-50%);
  background: radial-gradient(closest-side, rgba(122, 77, 255, 0.35), transparent 70%);
  pointer-events: none;
}
.footer-grid {
  position: relative;
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1.2fr;
  gap: 36px;
  padding: 64px 0 40px;
}
.footer-col { min-width: 0; }
.footer-col--brand {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 16px;
}
.footer-title {
  margin-bottom: 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.2em;
  color: var(--neon);
}
.footer-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.footer-list li { line-height: 1.65; }
.footer-link {
  font-size: 14.5px;
  color: var(--ink-70);
  transition: color 0.25s ease;
}
.footer-link:hover { color: var(--white); }
.footer-contact {
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: var(--ink-70);
  word-break: break-word;
}
.footer-note {
  max-width: 34ch;
  font-size: 14.5px;
  color: var(--ink-70);
}
.footer-meta {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--ink-50);
}
.footer-base {
  position: relative;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 22px 0 34px;
  border-top: 1px solid var(--line);
}
.footer-copy {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--ink-50);
}
.top-button {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--line-strong);
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.08em;
  color: var(--neon);
  cursor: pointer;
  transition: background 0.25s ease, transform 0.25s ease;
}
.top-button::before { content: "↑"; }
.top-button:hover {
  background: rgba(57, 230, 242, 0.12);
  transform: translateY(-2px);
}

/* ---------- 通用结构 ---------- */
.breadcrumbs {
  padding: 18px 0;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.06em;
}
.breadcrumbs__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}
.breadcrumbs__item {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--ink-50);
}
.breadcrumbs__item + .breadcrumbs__item::before {
  content: "/";
  color: rgba(201, 210, 227, 0.3);
}
.breadcrumbs__link {
  color: var(--ink-70);
  border-bottom: 1px solid transparent;
  transition: color 0.2s ease, border-color 0.2s ease;
}
.breadcrumbs__link:hover {
  color: var(--neon);
  border-bottom-color: var(--neon);
}
.breadcrumbs__current { color: var(--white); }

.section {
  position: relative;
  padding: 80px 0;
}
.section--tight { padding: 48px 0; }

.section-head {
  max-width: 760px;
  margin-bottom: 36px;
}
.section-head__eyebrow {
  display: block;
  margin-bottom: 14px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.18em;
  color: var(--neon);
}
.section-head__title { font-size: clamp(26px, 3.4vw, 42px); }
.section-head__lead {
  margin-top: 14px;
  font-size: 17px;
  color: var(--ink-70);
}

.prose {
  max-width: 74ch;
  color: var(--ink-90);
}
.prose p { margin-bottom: 1.1em; }
.prose h2 {
  margin: 2em 0 0.6em;
  padding-top: 0.5em;
  border-top: 1px solid var(--line);
}
.prose h3 {
  margin: 1.6em 0 0.5em;
  color: var(--neon);
}
.prose ul {
  margin: 0 0 1.2em;
  padding-left: 0;
}
.prose ul li {
  position: relative;
  margin-bottom: 0.5em;
  padding-left: 20px;
}
.prose ul li::before {
  content: "";
  position: absolute;
  top: 0.72em;
  left: 0;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--gold);
  box-shadow: 0 0 12px rgba(255, 184, 77, 0.7);
}
.prose a {
  color: var(--neon);
  border-bottom: 1px solid rgba(57, 230, 242, 0.35);
}
.prose a:hover { border-bottom-color: var(--neon); }

/* ---------- 网格与卡片 ---------- */
.grid { display: grid; gap: 24px; }
.grid--2 { grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }
.grid--3 { grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }
.grid--4 { grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); }
.grid--rail { grid-template-columns: minmax(0, 270px) minmax(0, 1fr); gap: 40px; }

.card {
  position: relative;
  display: block;
  padding: 26px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--line);
  background: linear-gradient(150deg, rgba(59, 30, 110, 0.42), rgba(10, 15, 44, 0.72) 62%);
  transition: transform 0.35s ease, border-color 0.35s ease, box-shadow 0.35s ease;
}
.card:hover {
  transform: translateY(-4px);
  border-color: rgba(57, 230, 242, 0.45);
  box-shadow: var(--shadow-hover);
}
.card--accent {
  border-color: rgba(255, 184, 77, 0.4);
  background: linear-gradient(150deg, rgba(122, 77, 255, 0.3), rgba(10, 15, 44, 0.78) 68%);
}
.card__eyebrow {
  display: block;
  margin-bottom: 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--gold);
}
.card__title {
  margin-bottom: 10px;
  font-size: 20px;
}
.card__body {
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--ink-70);
}
.card__meta {
  margin-top: 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--ink-50);
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 13px;
  border-radius: var(--radius-pill);
  border: 1px solid currentColor;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--neon);
  background: rgba(57, 230, 242, 0.08);
}
.chip--cyan { color: var(--neon); background: rgba(57, 230, 242, 0.08); }
.chip--gold { color: var(--gold); background: rgba(255, 184, 77, 0.1); }
.chip--violet { color: #B79CFF; background: rgba(122, 77, 255, 0.14); }
.chip--pink { color: var(--alert); background: rgba(255, 94, 168, 0.12); }
.chip--green { color: var(--download); background: rgba(76, 217, 160, 0.12); }

/* ---------- 折叠面板 ---------- */
.fold {
  margin-bottom: 12px;
  overflow: hidden;
  border-radius: var(--radius-md);
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.03);
}
.fold__summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 16px 20px;
  color: var(--white);
  font-weight: 600;
  cursor: pointer;
  list-style: none;
}
.fold__summary::-webkit-details-marker { display: none; }
.fold__summary::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 18px;
  line-height: 1;
  color: var(--neon);
}
details[open] .fold__summary::after { content: "–"; }
.fold__body {
  padding: 0 20px 18px;
  font-size: 15.5px;
  color: var(--ink-70);
}

/* ---------- 流程与数据 ---------- */
.timeline {
  position: relative;
  padding-left: 28px;
}
.timeline::before {
  content: "";
  position: absolute;
  top: 6px;
  bottom: 6px;
  left: 6px;
  width: 1px;
  background: linear-gradient(180deg, rgba(57, 230, 242, 0.6), rgba(122, 77, 255, 0.25));
}
.timeline__item {
  position: relative;
  padding-bottom: 26px;
}
.timeline__dot {
  position: absolute;
  top: 8px;
  left: -28px;
  width: 13px;
  height: 13px;
  border-radius: 50%;
  border: 2px solid var(--neon);
  background: var(--space-void);
  box-shadow: 0 0 14px rgba(57, 230, 242, 0.6);
}
.timeline__stamp {
  display: block;
  margin-bottom: 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--gold);
}
.timeline__title {
  margin-bottom: 6px;
  font-size: 18px;
}
.timeline__text {
  font-size: 15.5px;
  color: var(--ink-70);
}

.spec-list {
  overflow: hidden;
  border-radius: var(--radius-lg);
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.02);
}
.spec-list__row {
  display: grid;
  grid-template-columns: minmax(120px, 200px) minmax(0, 1fr);
  gap: 16px;
  padding: 14px 20px;
  border-bottom: 1px solid var(--line);
}
.spec-list__row:last-child { border-bottom: 0; }
.spec-list__key {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.08em;
  color: var(--neon);
}
.spec-list__value { color: var(--ink-90); }

.stat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 18px;
}
.stat {
  padding: 20px;
  border-radius: var(--radius-md);
  border: 1px solid var(--line);
  background: rgba(27, 58, 140, 0.18);
}
.stat__value {
  display: block;
  font-family: var(--font-head);
  font-size: 30px;
  font-weight: 800;
  letter-spacing: 0.02em;
  color: var(--gold);
}
.stat__label {
  display: block;
  margin-top: 6px;
  font-size: 14px;
  color: var(--ink-70);
}

/* ---------- 目录轨道 ---------- */
.toc {
  position: sticky;
  top: calc(var(--header-h) + 24px);
  padding: 20px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--line);
  background: rgba(10, 15, 44, 0.6);
  backdrop-filter: blur(8px);
}
.toc__title {
  display: block;
  margin-bottom: 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--ink-50);
}
.toc__list {
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.toc__item { display: block; }
.toc__link {
  display: block;
  padding: 9px 12px;
  border-radius: var(--radius-pill);
  border-left: 2px solid transparent;
  font-size: 14.5px;
  color: var(--ink-70);
  transition: color 0.25s ease, background 0.25s ease;
}
.toc__link:hover {
  color: var(--white);
  background: rgba(57, 230, 242, 0.06);
}
.toc__link[aria-current="true"] {
  color: var(--neon);
  background: rgba(57, 230, 242, 0.1);
}

/* ---------- 图片容器与动作 ---------- */
.media-frame {
  position: relative;
  display: block;
  overflow: hidden;
  border-radius: var(--radius-xl);
  border: 1px solid var(--line);
  background: radial-gradient(130% 120% at 18% 0%, rgba(59, 30, 110, 0.8), rgba(10, 15, 44, 0.92));
  aspect-ratio: 16 / 9;
}
.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: radial-gradient(circle at 50% 50%, transparent 40%, rgba(57, 230, 242, 0.08) 72%, transparent 74%);
}
.media-frame__img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.media-frame__caption {
  position: absolute;
  right: 0;
  bottom: 0;
  left: 0;
  padding: 16px 18px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--silver);
  background: linear-gradient(180deg, transparent, rgba(10, 15, 44, 0.9));
}
.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--tall { aspect-ratio: 4 / 5; }

.action-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px;
  margin-top: 26px;
}

/* ---------- 滚动显现 ---------- */
.reveal {
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.has-js .reveal {
  opacity: 0;
  transform: translateY(18px);
}
.has-js .reveal.is-visible {
  opacity: 1;
  transform: none;
}

/* ---------- 响应式 ---------- */
@media (max-width: 1119px) {
  .lang-chip { display: none; }
}

@media (max-width: 979px) {
  .nav-toggle { display: inline-flex; }
  .nav-track {
    position: absolute;
    top: 100%;
    right: 0;
    left: 0;
    display: none;
    padding: 12px 16px 20px;
    border-top: 1px solid var(--line);
    border-bottom: 1px solid var(--line);
    background: rgba(8, 12, 33, 0.98);
    backdrop-filter: blur(14px);
  }
  .nav-track[data-open] { display: block; }
  .nav-track__list {
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
  }
  .nav-track__link {
    padding: 13px 14px;
    border-radius: var(--radius-md);
    font-size: 15px;
  }
  .brand__tagline { display: none; }
  .grid--rail { grid-template-columns: minmax(0, 1fr); gap: 28px; }
  .toc { position: static; }
}

@media (max-width: 767px) {
  :root {
    --header-h: 64px;
    --shell: min(1240px, calc(100% - 32px));
  }
  body {
    font-size: 16px;
    line-height: 1.8;
    background-attachment: scroll;
  }
  .brand__mark { width: 36px; height: 36px; }
  .brand__name { font-size: 15.5px; }
  .btn--compact { padding: 8px 13px; font-size: 12.5px; }
  .section { padding: 56px 0; }
  .section--tight { padding: 36px 0; }
  .card { padding: 22px; }
  .spec-list__row { grid-template-columns: minmax(0, 1fr); gap: 4px; }
  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 28px;
    padding: 48px 0 32px;
  }
  .footer-col--brand { grid-column: 1 / -1; }
  .footer-base {
    flex-direction: column;
    align-items: flex-start;
  }
  .site-footer { margin-top: 64px; }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  html { scroll-behavior: auto; }
  .has-js .reveal {
    opacity: 1;
    transform: none;
  }
}