/* ==========================================================================
   /assets/site.css
   线上赛场 · 共享外壳 / 基础组件 / 排版系统
   ========================================================================== */

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

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 156px;
}

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

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

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

button, input, select, textarea { font: inherit; color: inherit; }

a { color: inherit; }

table { border-collapse: collapse; border-spacing: 0; }

[hidden] { display: none !important; }

/* ---------- 2. Tokens ---------- */
:root {
  /* palette */
  --void-black: #0A0E0D;
  --pitch-deep: #10241A;
  --turf-mid: #1C3A2B;
  --shade-teal: #071310;
  --chalk: #EDE9DC;
  --mist: #9AA79C;
  --signal-cyan: #35F2C0;
  --alert-orange: #FF7A2F;
  --gold-trace: #C9A227;
  --cyan-dim: #1E8F76;

  /* derived */
  --line-gold: rgba(201, 162, 39, 0.42);
  --line-cyan: rgba(53, 242, 192, 0.34);
  --line-soft: rgba(154, 167, 156, 0.18);
  --veil: rgba(7, 19, 16, 0.72);
  --text-body: #D9D5C8;

  /* type */
  --font-display: system-ui, -apple-system, "Noto Sans SC", "Source Han Sans SC", "PingFang SC", sans-serif;
  --font-serif: "Noto Serif SC", "Songti SC", Georgia, "Times New Roman", serif;
  --font-body: "Noto Sans SC", "PingFang SC", system-ui, -apple-system, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, "JetBrains Mono", "Roboto Mono", Menlo, Consolas, monospace;

  /* measures */
  --shell: 1280px;
  --gutter: clamp(18px, 4vw, 48px);
  --radius-sharp: 3px;
  --radius-md: 18px;
  --radius-lg: 28px;
  --pill: 999px;

  --ease-out: cubic-bezier(.22, .61, .36, 1);
}

/* ---------- 3. Base ---------- */
body {
  min-height: 100vh;
  background-color: var(--void-black);
  background-image:
    linear-gradient(90deg, rgba(53, 242, 192, 0.030) 1px, transparent 1px),
    linear-gradient(180deg, rgba(53, 242, 192, 0.022) 1px, transparent 1px);
  background-size: 104px 104px, 104px 104px;
  color: var(--chalk);
  font-family: var(--font-body);
  font-size: 17px;
  font-weight: 400;
  line-height: 1.75;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

::selection {
  background: rgba(53, 242, 192, 0.28);
  color: var(--chalk);
}

/* ---------- 4. Layout primitives ---------- */
.shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section {
  position: relative;
  padding-block: clamp(48px, 7vw, 96px);
}

.section--pitch { background: var(--pitch-deep); }

.section--shade { background: var(--shade-teal); }

.section--ruled { border-top: 1px solid var(--line-gold); }

.section-head {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: clamp(24px, 3.4vw, 44px);
}

/* ---------- 5. Type ---------- */
.display {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(3.4rem, 8.5vw, 8.5rem);
  line-height: 0.92;
  letter-spacing: -0.02em;
  color: var(--chalk);
}

.section-title {
  margin: 0;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: clamp(1.65rem, 3.4vw, 2.75rem);
  line-height: 1.3;
  letter-spacing: 0.01em;
  color: var(--chalk);
}

.section-lede {
  max-width: 62ch;
  margin: 0;
  font-size: 16.5px;
  line-height: 1.75;
  color: var(--mist);
}

.kicker {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--signal-cyan);
}

.kicker::before {
  content: "";
  width: 24px;
  height: 1px;
  background: var(--gold-trace);
}

.prose {
  max-width: 68ch;
  font-size: 17px;
  line-height: 1.78;
  color: var(--text-body);
}

.prose > * + * { margin-top: 1.1em; }

.prose h3,
.prose h4 {
  margin-top: 1.7em;
  font-family: var(--font-serif);
  font-weight: 700;
  line-height: 1.35;
  color: var(--chalk);
}

.prose h3 { font-size: 1.45rem; }
.prose h4 { font-size: 1.2rem; }

.prose strong { color: var(--chalk); font-weight: 700; }

.prose ul,
.prose ol {
  padding-left: 1.3em;
  list-style: disc;
}

.prose ol { list-style: decimal; }

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

.prose code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  color: var(--signal-cyan);
}

/* ---------- 6. Buttons & pills ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  border: 1px solid var(--line-cyan);
  border-radius: var(--pill);
  background: transparent;
  color: var(--chalk);
  font-family: var(--font-body);
  font-size: 14.5px;
  font-weight: 600;
  letter-spacing: 0.02em;
  line-height: 1.2;
  text-decoration: none;
  cursor: pointer;
  transition: background-color .2s var(--ease-out),
              border-color .2s var(--ease-out),
              color .2s var(--ease-out),
              transform .2s var(--ease-out);
}

.btn:hover {
  background: rgba(53, 242, 192, 0.12);
  border-color: var(--signal-cyan);
}

.btn:active { transform: translateY(1px); }

.btn--signal {
  background: var(--signal-cyan);
  border-color: var(--signal-cyan);
  color: #04120D;
}

.btn--signal:hover {
  background: #61F7CE;
  color: #04120D;
}

.btn--gold {
  border-color: var(--line-gold);
  color: var(--gold-trace);
}

.btn--gold:hover {
  background: rgba(201, 162, 39, 0.12);
  border-color: var(--gold-trace);
  color: var(--chalk);
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 12px;
  border: 1px solid var(--line-soft);
  border-radius: var(--pill);
  background: rgba(28, 58, 43, 0.7);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--mist);
}

.chip--signal {
  border-color: var(--line-cyan);
  background: rgba(53, 242, 192, 0.09);
  color: var(--signal-cyan);
}

.chip--alert {
  border-color: rgba(255, 122, 47, 0.42);
  background: rgba(255, 122, 47, 0.09);
  color: var(--alert-orange);
}

.chip--gold {
  border-color: var(--line-gold);
  background: rgba(201, 162, 39, 0.08);
  color: var(--gold-trace);
}

.caliber {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 3px 11px;
  border: 1px solid var(--line-gold);
  border-radius: var(--pill);
  background: rgba(201, 162, 39, 0.06);
  font-family: var(--font-mono);
  font-size: 12px;
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.05em;
  color: var(--gold-trace);
  cursor: pointer;
  transition: background-color .2s var(--ease-out), border-color .2s var(--ease-out);
}

.caliber:hover { background: rgba(201, 162, 39, 0.14); }

.caliber[data-copied="true"] {
  border-color: var(--signal-cyan);
  color: var(--signal-cyan);
}

/* ---------- 7. Surfaces ---------- */
.panel {
  padding: clamp(18px, 2.4vw, 32px);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-sharp);
  background:
    linear-gradient(165deg, rgba(28, 58, 43, 0.92), rgba(7, 19, 16, 0.92));
}

.panel--gold { border-color: var(--line-gold); }

.panel--cyan { border-color: var(--line-cyan); }

.bento {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(12px, 1.4vw, 20px);
}

.bento__cell {
  position: relative;
  grid-column: span 12;
  padding: clamp(18px, 2.2vw, 30px);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-sharp);
  background:
    linear-gradient(160deg, rgba(28, 58, 43, 0.95), rgba(7, 19, 16, 0.95));
  overflow: hidden;
}

.grid-2,
.grid-3 {
  display: grid;
  gap: clamp(14px, 1.8vw, 26px);
  grid-template-columns: minmax(0, 1fr);
}

/* ---------- 8. Data blocks ---------- */
.stat {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.stat__value {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(2.4rem, 5vw, 4.4rem);
  line-height: 1;
  letter-spacing: -0.02em;
  font-variant-numeric: tabular-nums;
  color: var(--chalk);
}

.stat__value--signal { color: var(--signal-cyan); }

.stat__label {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--mist);
}

.table-wrap {
  width: 100%;
  overflow-x: auto;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-sharp);
  background: rgba(7, 19, 16, 0.62);
}

.data-table {
  width: 100%;
  min-width: 560px;
  font-size: 14.5px;
}

.data-table thead th {
  position: sticky;
  top: 0;
  z-index: 2;
  padding: 12px 16px;
  border-bottom: 1px solid var(--line-gold);
  background: var(--pitch-deep);
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-align: left;
  text-transform: uppercase;
  color: var(--mist);
  white-space: nowrap;
}

.data-table td {
  padding: 12px 16px;
  border-bottom: 1px solid var(--line-soft);
  color: var(--chalk);
  vertical-align: top;
}

.data-table tbody tr:nth-child(even) { background: rgba(28, 58, 43, 0.35); }

.data-table tbody tr:hover { background: rgba(53, 242, 192, 0.05); }

.data-table td.num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  text-align: right;
  white-space: nowrap;
}

/* ---------- 9. Disclosure / tabs ---------- */
.faq { border-top: 1px solid var(--line-soft); }

.faq details { border-bottom: 1px solid var(--line-soft); }

.faq summary {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 18px 4px;
  font-size: 17px;
  font-weight: 600;
  line-height: 1.6;
  cursor: pointer;
  list-style: none;
}

.faq summary::-webkit-details-marker { display: none; }

.faq summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 18px;
  color: var(--signal-cyan);
}

.faq details[open] > summary::after { content: "–"; }

.faq .faq__body {
  padding: 0 4px 20px;
  max-width: 68ch;
  color: var(--text-body);
  font-size: 16px;
  line-height: 1.78;
}

.tabs {
  display: inline-flex;
  flex-wrap: wrap;
  gap: 4px;
  padding: 4px;
  border: 1px solid var(--line-soft);
  border-radius: var(--pill);
  background: rgba(7, 19, 16, 0.72);
}

.tabs [role="tab"] {
  padding: 8px 16px;
  border: 0;
  border-radius: var(--pill);
  background: transparent;
  color: var(--mist);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: background-color .2s var(--ease-out), color .2s var(--ease-out);
}

.tabs [role="tab"]:hover { color: var(--chalk); }

.tabs [role="tab"][aria-selected="true"] {
  background: var(--signal-cyan);
  color: #04120D;
}

/* ---------- 10. Breadcrumb ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.05em;
  color: var(--mist);
}

.breadcrumb a {
  color: var(--mist);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .2s var(--ease-out), border-color .2s var(--ease-out);
}

.breadcrumb a:hover {
  color: var(--signal-cyan);
  border-bottom-color: var(--line-cyan);
}

.breadcrumb__sep { color: var(--cyan-dim); }

/* ---------- 11. Media frames ---------- */
.media-frame {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-md);
  background:
    linear-gradient(150deg, var(--shade-teal), var(--pitch-deep));
}

.media-frame::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 26% 18%, rgba(53, 242, 192, 0.12), transparent 58%);
  pointer-events: none;
}

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

.media-frame--16x9 { aspect-ratio: 16 / 9; }
.media-frame--4x3  { aspect-ratio: 4 / 3; }
.media-frame--1x1  { aspect-ratio: 1 / 1; }
.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--tall { aspect-ratio: 3 / 4; }

/* ---------- 12. Reveal & TOC protocol ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity .55s var(--ease-out), transform .55s var(--ease-out);
}

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

[data-toc-link] {
  transition: color .2s var(--ease-out), border-color .2s var(--ease-out);
}

[data-toc-link].is-active,
[data-toc-link][aria-current="true"] {
  color: var(--signal-cyan);
  border-color: var(--line-cyan);
}

/* ---------- 13. Skip link ---------- */
.skip-link {
  position: absolute;
  top: -80px;
  left: 16px;
  z-index: 200;
  padding: 10px 18px;
  border: 1px solid var(--signal-cyan);
  border-radius: var(--pill);
  background: var(--pitch-deep);
  color: var(--signal-cyan);
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
  transition: top .2s var(--ease-out);
}

.skip-link:focus { top: 12px; }

/* ---------- 14. Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 90;
  border-bottom: 1px solid var(--line-gold);
  background:
    linear-gradient(180deg, rgba(7, 19, 16, 0.985), rgba(10, 14, 13, 0.94));
  backdrop-filter: blur(10px);
}

.header-top__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding-block: 14px 12px;
}

.brand-block {
  display: flex;
  align-items: center;
  min-width: 0;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  flex: 0 0 auto;
  color: var(--chalk);
  text-decoration: none;
}

.brand__mark {
  position: relative;
  flex: 0 0 auto;
  width: 36px;
  height: 36px;
  border: 1px solid var(--line-cyan);
  border-radius: 11px;
  background: linear-gradient(145deg, var(--turf-mid), var(--shade-teal));
}

.brand__mark::before {
  content: "";
  position: absolute;
  top: 7px;
  bottom: 7px;
  left: 17px;
  width: 2px;
  border-radius: 2px;
  background: var(--signal-cyan);
}

.brand__mark::after {
  content: "";
  position: absolute;
  top: 17px;
  right: 7px;
  left: 7px;
  height: 2px;
  border-radius: 2px;
  background: var(--gold-trace);
}

.brand__text {
  display: flex;
  flex-direction: column;
  line-height: 1.15;
}

.brand__name {
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 800;
  letter-spacing: 0.01em;
  color: var(--chalk);
}

.brand__sub {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--mist);
}

.header-statement {
  max-width: 46ch;
  margin-left: 20px;
  padding-left: 20px;
  border-left: 1px solid var(--line-gold);
  font-size: 14px;
  line-height: 1.6;
  color: var(--mist);
}

.header-top__actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: 0 0 auto;
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  padding: 9px 16px 9px 14px;
  border: 1px solid var(--line-cyan);
  border-radius: var(--pill);
  background: rgba(28, 58, 43, 0.7);
  color: var(--chalk);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
}

.nav-toggle__bars {
  position: relative;
  display: block;
  width: 16px;
  height: 2px;
  border-radius: 2px;
  background: var(--signal-cyan);
}

.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 16px;
  height: 2px;
  border-radius: 2px;
  background: var(--signal-cyan);
}

.nav-toggle__bars::before { top: -5px; }
.nav-toggle__bars::after  { top: 5px; }

.header-nav {
  border-top: 1px solid var(--line-soft);
  background: rgba(7, 19, 16, 0.74);
}

.header-nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding-block: 6px;
}

.nav-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 4px;
}

.nav-list a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 16px;
  border: 1px solid transparent;
  border-radius: var(--pill);
  font-size: 15px;
  font-weight: 500;
  color: var(--mist);
  text-decoration: none;
  transition: color .2s var(--ease-out),
              background-color .2s var(--ease-out),
              border-color .2s var(--ease-out);
}

.nav-list a:hover {
  background: rgba(237, 233, 220, 0.05);
  color: var(--chalk);
}

.nav-list a[aria-current="page"] {
  border-color: var(--line-cyan);
  background: rgba(53, 242, 192, 0.10);
  color: var(--signal-cyan);
}

.nav-list a[aria-current="page"]::after {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--signal-cyan);
  box-shadow: 0 0 0 3px rgba(53, 242, 192, 0.18);
}

.nav-note {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.1em;
  color: var(--cyan-dim);
  white-space: nowrap;
}

.scroll-progress {
  position: absolute;
  right: 0;
  bottom: -1px;
  left: 0;
  height: 2px;
  pointer-events: none;
}

.scroll-progress > span {
  display: block;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, var(--cyan-dim), var(--signal-cyan));
  transform: scaleX(0);
  transform-origin: 0 50%;
}

/* ---------- 15. Footer ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(56px, 9vw, 130px);
  background:
    radial-gradient(120% 96% at 50% 122%, rgba(28, 58, 43, 0.62), transparent 62%),
    linear-gradient(180deg, var(--void-black), var(--shade-teal));
}

.site-footer::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--gold-trace), transparent);
  opacity: 0.7;
}

.footer-inner {
  display: grid;
  grid-template-columns: minmax(0, 1.7fr) repeat(3, minmax(0, 0.8fr)) minmax(0, 1.6fr);
  gap: clamp(24px, 3vw, 44px);
  padding-block: clamp(44px, 6vw, 76px) clamp(30px, 4vw, 48px);
}

.footer-brand .brand { margin-bottom: 18px; }

.footer-summary {
  max-width: 40ch;
  font-size: 15px;
  line-height: 1.72;
  color: var(--mist);
}

.footer-col__title {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--gold-trace);
}

.footer-col ul,
.footer-contact__list {
  display: grid;
  gap: 8px;
}

.footer-col a {
  display: inline-block;
  padding-block: 2px;
  border-bottom: 1px solid transparent;
  font-size: 15px;
  color: var(--mist);
  text-decoration: none;
  transition: color .2s var(--ease-out), border-color .2s var(--ease-out);
}

.footer-col a:hover {
  border-bottom-color: var(--line-cyan);
  color: var(--signal-cyan);
}

.footer-contact__list li {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.footer-contact__k {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.12em;
  color: var(--cyan-dim);
}

.footer-contact__v {
  font-size: 14.5px;
  line-height: 1.6;
  color: var(--chalk);
  word-break: break-word;
}

.footer-legal {
  border-top: 1px solid var(--line-soft);
}

.footer-legal__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 24px;
  padding-block: 18px 26px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.05em;
  color: var(--mist);
}

.footer-legal__icp { color: var(--gold-trace); }

.footer-legal__note { color: var(--cyan-dim); }

/* ---------- 16. Back to top ---------- */
.to-top {
  position: fixed;
  right: clamp(14px, 3vw, 32px);
  bottom: clamp(14px, 3vw, 32px);
  z-index: 95;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 18px;
  border: 1px solid var(--line-cyan);
  border-radius: var(--pill);
  background: rgba(16, 36, 26, 0.94);
  color: var(--chalk);
  font-size: 13.5px;
  font-weight: 600;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: opacity .24s var(--ease-out),
              transform .24s var(--ease-out),
              visibility .24s var(--ease-out),
              border-color .2s var(--ease-out);
}

.to-top[data-visible="true"] {
  opacity: 1;
  visibility: visible;
  transform: none;
}

.to-top:hover { border-color: var(--signal-cyan); }

.to-top__glyph {
  font-family: var(--font-mono);
  color: var(--signal-cyan);
}

/* ---------- 17. Responsive ---------- */
@media (min-width: 640px) {
  .grid-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}

@media (min-width: 900px) {
  .bento__cell--6 { grid-column: span 6; }
  .bento__cell--4 { grid-column: span 4; }
  .bento__cell--8 { grid-column: span 8; }
  .bento__cell--3 { grid-column: span 3; }
  .bento__cell--9 { grid-column: span 9; }
}

@media (max-width: 1100px) {
  .header-statement { display: none; }
}

@media (max-width: 1080px) {
  .footer-inner { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-brand { grid-column: 1 / -1; }
}

@media (max-width: 900px) {
  html { scroll-padding-top: 96px; }

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

  .header-nav {
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    transition: max-height .3s var(--ease-out), opacity .22s var(--ease-out);
  }

  .header-nav[data-open="true"] {
    max-height: 460px;
    opacity: 1;
  }

  .header-nav__inner { display: block; padding-block: 0; }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
    padding-block: 10px 14px;
  }

  .nav-list a {
    width: 100%;
    padding: 12px 16px;
    border-radius: 14px;
    font-size: 16px;
  }

  .nav-note { display: none; }
}

@media (max-width: 620px) {
  body { font-size: 16px; }

  .footer-inner { grid-template-columns: minmax(0, 1fr); }

  .footer-legal__inner { justify-content: flex-start; }

  .header-top__actions .btn--ghost { display: none; }
}

/* ---------- 18. Motion preference ---------- */
@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;
  }

  .scroll-progress > span { transition: none; }
}