/* ============================================================
   STREET ARCADE · 共享样式表 /assets/site.css
   夜色街机厅坐标系统：深炭黑底 + 霓虹紫/电光蓝坐标 + 街机橙行动
   ============================================================ */

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

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

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

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

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

button, input, select, textarea { font: inherit; color: inherit; }
button { background: none; border: 0; padding: 0; cursor: pointer; }

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

table { border-collapse: collapse; width: 100%; }

hr { border: 0; }

/* ---------- 2. Design tokens ---------- */
:root {
  --ink: #07060E;
  --ink-2: #12101F;
  --ink-3: #1A1730;
  --purple: #7C3AED;
  --blue: #22D3EE;
  --orange: #FF7A1A;
  --gold: #FFC94A;
  --green: #33D69F;
  --paper: #E9E6FF;
  --muted: #A79FD0;

  --line: rgba(34, 211, 238, 0.28);
  --line-soft: rgba(167, 159, 208, 0.18);
  --glass: rgba(18, 16, 31, 0.62);

  --font-display: "Alibaba PuHuiTi 3.0", "Noto Sans SC", "Montserrat",
    "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --font-body: "Noto Sans SC", "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", "IBM Plex Mono", ui-monospace, SFMono-Regular,
    Menlo, Consolas, monospace;

  --step-1: 12px;
  --step-2: 14px;
  --step-3: 16px;
  --step-4: 20px;
  --step-5: 28px;
  --step-6: 40px;
  --step-7: 64px;
  --step-8: 96px;

  --wrap: 1180px;
  --gutter: 24px;
  --radius: 4px;
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

/* ---------- 3. Base ---------- */
html { scroll-behavior: smooth; }

body {
  min-height: 100vh;
  background-color: var(--ink);
  background-image:
    radial-gradient(920px 620px at 8% -10%, rgba(124, 58, 237, 0.30), transparent 64%),
    radial-gradient(780px 540px at 96% 2%, rgba(34, 211, 238, 0.16), transparent 62%),
    radial-gradient(circle, rgba(233, 230, 255, 0.07) 1px, transparent 1.5px);
  background-size: auto, auto, 28px 28px;
  background-repeat: no-repeat, no-repeat, repeat;
  color: var(--paper);
  font-family: var(--font-body);
  font-size: var(--step-3);
  line-height: 1.75;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 900;
  line-height: 1.15;
  letter-spacing: -0.02em;
  color: var(--paper);
  text-wrap: balance;
}

h1 { font-size: clamp(32px, 5.4vw, 64px); }
h2 { font-size: clamp(24px, 3.4vw, 40px); }
h3 { font-size: var(--step-4); }
h4 { font-size: var(--step-3); font-weight: 700; letter-spacing: 0; }

p { line-height: 1.75; }

strong { font-weight: 700; color: #FFFFFF; }

::selection { background: var(--purple); color: #FFFFFF; }

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

#main-content:focus-visible {
  outline: 2px solid var(--blue);
  outline-offset: 4px;
}

/* ---------- 4. Utilities ---------- */
.wrap {
  width: min(var(--wrap), calc(100% - var(--gutter) * 2));
  margin-inline: auto;
}

.mono {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.04em;
}

.muted { color: var(--muted); }
.gold { color: var(--gold); }

.lead {
  max-width: 34em;
  font-size: clamp(16px, 1.6vw, 19px);
  line-height: 1.85;
  color: var(--muted);
}

.prose { max-width: 34em; }
.prose p + p { margin-top: 1em; }

.link {
  color: var(--blue);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
}
.link:hover { color: var(--gold); }

.divider {
  height: 9px;
  border-top: 1px solid var(--line-soft);
  background-image: repeating-linear-gradient(
    90deg,
    rgba(34, 211, 238, 0.42) 0 1px,
    transparent 1px 12px
  );
  background-repeat: no-repeat;
  background-size: 100% 9px;
  opacity: 0.8;
}

/* ---------- 5. Skip link ---------- */
.skip-link {
  position: absolute;
  left: 50%;
  top: 10px;
  z-index: 200;
  transform: translate(-50%, -220%);
  padding: 10px 20px;
  border-radius: 3px;
  background: var(--gold);
  color: #12060A;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--step-2);
  letter-spacing: 0.06em;
  transition: transform 0.18s var(--ease);
}
.skip-link:focus { transform: translate(-50%, 0); }

/* ---------- 6. Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  border-bottom: 1px solid var(--line);
  background: linear-gradient(
    180deg,
    rgba(7, 6, 14, 0.96),
    rgba(7, 6, 14, 0.82) 72%,
    rgba(7, 6, 14, 0.66)
  );
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}

.site-header__inner {
  display: grid;
  justify-items: center;
  gap: 8px;
  padding: 12px 0 0;
  position: relative;
}

.scroll-meter {
  position: absolute;
  left: 0;
  bottom: 0;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--blue), var(--purple) 55%, var(--orange));
  box-shadow: 0 0 10px rgba(34, 211, 238, 0.7);
  transition: width 0.08s linear;
  z-index: 2;
}

.masthead__coord {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  width: 100%;
  font-size: var(--step-1);
  letter-spacing: 0.18em;
  line-height: 1.4;
  text-transform: uppercase;
  color: var(--muted);
}

.masthead__coord-item--dim { color: rgba(167, 159, 208, 0.72); }

.masthead__badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 2px 10px;
  border: 1px solid rgba(255, 201, 74, 0.5);
  border-radius: 999px;
  background: rgba(255, 201, 74, 0.08);
  color: var(--gold);
  font-size: 11px;
  letter-spacing: 0.12em;
  white-space: nowrap;
}

.brand {
  display: grid;
  justify-items: center;
  gap: 2px;
  text-align: center;
  padding: 2px 0 4px;
}

.brand__name {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(24px, 4.4vw, 40px);
  line-height: 1.12;
  letter-spacing: -0.02em;
  color: var(--paper);
  text-shadow:
    2px 0 rgba(255, 122, 26, 0.32),
    -2px 0 rgba(34, 211, 238, 0.32);
  transition: text-shadow 0.2s var(--ease), color 0.2s var(--ease);
}

.brand:hover .brand__name,
.brand:focus-visible .brand__name {
  color: #FFFFFF;
  text-shadow:
    3px 0 rgba(255, 122, 26, 0.55),
    -3px 0 rgba(34, 211, 238, 0.55),
    0 0 28px rgba(124, 58, 237, 0.55);
}

.brand__sub {
  font-size: 11px;
  letter-spacing: 0.34em;
  color: var(--muted);
  text-transform: uppercase;
}

.nav-bar {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  width: 100%;
  padding-bottom: 6px;
}

.nav-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 44px;
  padding: 8px 18px;
  border: 1px solid rgba(34, 211, 238, 0.45);
  border-radius: 3px;
  background: rgba(18, 16, 31, 0.72);
  color: var(--paper);
  font-family: var(--font-mono);
  font-size: var(--step-1);
  letter-spacing: 0.16em;
  transition: border-color 0.18s var(--ease), box-shadow 0.18s var(--ease);
}
.nav-toggle:hover {
  border-color: var(--blue);
  box-shadow: 0 0 20px rgba(34, 211, 238, 0.32);
}

.nav-toggle__bars {
  display: grid;
  gap: 3px;
  width: 18px;
}
.nav-toggle__bars span {
  display: block;
  height: 2px;
  border-radius: 1px;
  background: var(--blue);
  transition: transform 0.2s var(--ease), opacity 0.2s var(--ease);
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(1) {
  transform: translateY(5px) rotate(45deg);
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(3) {
  transform: translateY(-5px) rotate(-45deg);
}

.nav-toggle__label { letter-spacing: 0.24em; }

.nav { width: 100%; }

.nav__list {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 2px 6px;
  padding-bottom: 6px;
}

.nav__link {
  position: relative;
  display: inline-flex;
  align-items: center;
  padding: 8px 14px;
  border-radius: 3px;
  font-size: var(--step-2);
  font-weight: 500;
  letter-spacing: 0.06em;
  color: var(--muted);
  transition: color 0.18s var(--ease), background 0.18s var(--ease);
}

.nav__link::after {
  content: "";
  position: absolute;
  left: 14px;
  right: 14px;
  bottom: -2px;
  height: 2px;
  border-radius: 2px;
  background: var(--blue);
  box-shadow: 0 0 12px rgba(34, 211, 238, 0.8);
  transform: scaleX(0);
  transform-origin: center;
  transition: transform 0.22s var(--ease);
}

.nav__link:hover {
  color: var(--paper);
  background: rgba(124, 58, 237, 0.18);
}
.nav__link:hover::after { transform: scaleX(0.5); }

.nav__link[aria-current="page"] {
  color: #FFFFFF;
  font-weight: 700;
}
.nav__link[aria-current="page"]::after { transform: scaleX(1); }

.ruler {
  height: 7px;
  width: 100%;
  background-image: repeating-linear-gradient(
    90deg,
    rgba(34, 211, 238, 0.45) 0 1px,
    transparent 1px 12px
  );
  opacity: 0.6;
}

/* ---------- 7. Footer ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(48px, 7vw, 96px);
  padding: clamp(40px, 6vw, 72px) 0 24px;
  border-top: 1px solid var(--line);
  background: linear-gradient(
    180deg,
    rgba(18, 16, 31, 0.92),
    rgba(7, 6, 14, 0.99)
  );
}

.footer__grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1.4fr;
  gap: clamp(24px, 3vw, 48px);
  align-items: start;
}

.footer__col { min-width: 0; }
.footer__col--brand { max-width: 34ch; }

.footer__brand {
  display: inline-block;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(20px, 2.4vw, 26px);
  letter-spacing: -0.01em;
  line-height: 1.2;
  color: var(--paper);
  text-shadow:
    2px 0 rgba(255, 122, 26, 0.28),
    -2px 0 rgba(34, 211, 238, 0.28);
  transition: color 0.18s var(--ease), text-shadow 0.18s var(--ease);
}
.footer__brand:hover {
  color: #FFFFFF;
  text-shadow:
    3px 0 rgba(255, 122, 26, 0.5),
    -3px 0 rgba(34, 211, 238, 0.5),
    0 0 22px rgba(124, 58, 237, 0.5);
}

.footer__tagline {
  margin-top: 10px;
  color: var(--blue);
  font-size: var(--step-2);
  letter-spacing: 0.14em;
}

.footer__label {
  margin-bottom: 14px;
  font-family: var(--font-mono);
  font-size: var(--step-1);
  font-weight: 400;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--gold);
}

.footer__list { display: grid; gap: 8px; }

.footer__list a {
  display: inline-block;
  font-size: var(--step-2);
  color: var(--muted);
  border-bottom: 1px solid transparent;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}
.footer__list a:hover {
  color: var(--paper);
  border-bottom-color: rgba(34, 211, 238, 0.6);
}

.footer__contact {
  display: grid;
  gap: 6px;
  margin-top: 18px;
  font-size: var(--step-1);
  line-height: 1.7;
  color: var(--muted);
  word-break: break-word;
}

.footer__contact-key {
  display: inline-block;
  min-width: 44px;
  color: var(--blue);
  letter-spacing: 0.14em;
}

.footer__note {
  margin-top: 12px;
  font-size: var(--step-1);
  line-height: 1.7;
  color: rgba(167, 159, 208, 0.82);
}

.footer__bottom {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 8px 24px;
  margin-top: clamp(28px, 4vw, 48px);
  padding-top: 16px;
  border-top: 1px solid var(--line-soft);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: rgba(167, 159, 208, 0.75);
}

/* ---------- 8. Buttons & chips ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 48px;
  padding: 12px 26px;
  border: 1px solid transparent;
  border-radius: 3px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 15px;
  letter-spacing: 0.04em;
  text-align: center;
  transition: transform 0.18s var(--ease), box-shadow 0.18s var(--ease),
    background 0.18s var(--ease), color 0.18s var(--ease),
    border-color 0.18s var(--ease);
}
.btn:hover { transform: translateY(-2px); }

.btn--primary {
  background: var(--orange);
  color: #12060A;
  box-shadow: 0 8px 24px rgba(255, 122, 26, 0.28);
}
.btn--primary:hover {
  background: #FF8B3A;
  box-shadow: 0 10px 30px rgba(255, 122, 26, 0.45);
}

.btn--ghost {
  border-color: rgba(34, 211, 238, 0.55);
  background: rgba(34, 211, 238, 0.06);
  color: var(--blue);
}
.btn--ghost:hover {
  background: rgba(34, 211, 238, 0.14);
  color: #FFFFFF;
  box-shadow: 0 0 24px rgba(34, 211, 238, 0.3);
}

.btn--quiet {
  border-color: rgba(167, 159, 208, 0.35);
  background: transparent;
  color: var(--paper);
}
.btn--quiet:hover {
  border-color: var(--purple);
  color: #FFFFFF;
  box-shadow: 0 0 20px rgba(124, 58, 237, 0.35);
}

.btn-row {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-top: 32px;
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  border: 1px solid rgba(167, 159, 208, 0.35);
  border-radius: 999px;
  color: var(--muted);
  font-size: 13px;
  letter-spacing: 0.04em;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease),
    background 0.18s var(--ease), box-shadow 0.18s var(--ease);
}
.chip:hover {
  color: var(--paper);
  border-color: var(--purple);
}
.chip--active,
.chip[aria-pressed="true"] {
  background: var(--purple);
  border-color: var(--purple);
  color: #FFFFFF;
  box-shadow: 0 0 18px rgba(124, 58, 237, 0.5);
}

/* ---------- 9. Breadcrumb ---------- */
.breadcrumb {
  border-bottom: 1px solid var(--line-soft);
  background: rgba(18, 16, 31, 0.72);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

.breadcrumb__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: 10px 0;
  font-family: var(--font-mono);
  font-size: var(--step-1);
  letter-spacing: 0.08em;
  color: var(--muted);
}

.breadcrumb a { color: var(--muted); transition: color 0.18s var(--ease); }
.breadcrumb a:hover { color: var(--blue); }

.breadcrumb__sep { color: rgba(167, 159, 208, 0.5); }

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

/* ---------- 10. Sections & layout ---------- */
.section {
  position: relative;
  padding: clamp(48px, 7vw, 88px) 0;
  border-top: 1px solid var(--line-soft);
}
.section--flush { padding-top: 0; }
.section--alt {
  background: linear-gradient(
    180deg,
    rgba(18, 16, 31, 0.94),
    rgba(18, 16, 31, 0.62)
  );
}

.section__head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: 16px 24px;
  margin-bottom: clamp(24px, 3vw, 40px);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: var(--step-1);
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--blue);
}
.eyebrow::before {
  content: "";
  width: 22px;
  height: 1px;
  background: var(--blue);
  box-shadow: 0 0 10px var(--blue);
}

.grid { display: grid; gap: var(--gutter); }

.grid--2 { grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }
.grid--3 { grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }

.grid--rail {
  display: grid;
  grid-auto-flow: column;
  grid-auto-columns: minmax(260px, 1fr);
  gap: 18px;
  overflow-x: auto;
  padding-bottom: 10px;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
}
.grid--rail > * { scroll-snap-align: start; }

.card {
  position: relative;
  padding: clamp(18px, 2.4vw, 28px);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  background: linear-gradient(
    160deg,
    rgba(26, 23, 48, 0.88),
    rgba(18, 16, 31, 0.88)
  );
  transition: transform 0.18s var(--ease), border-color 0.18s var(--ease),
    box-shadow 0.18s var(--ease);
}
.card:hover {
  transform: translateY(-4px);
  border-color: rgba(124, 58, 237, 0.75);
  box-shadow: 0 0 24px rgba(124, 58, 237, 0.35);
}

.glass {
  background: var(--glass);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}

.readout {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 18px;
  padding: 8px 0;
  border-top: 1px dashed rgba(34, 211, 238, 0.28);
  border-bottom: 1px dashed rgba(34, 211, 238, 0.28);
  font-family: var(--font-mono);
  font-size: var(--step-1);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}
.readout b { font-weight: 500; color: var(--gold); }

.coord-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 2px 8px;
  border: 1px solid rgba(167, 159, 208, 0.28);
  border-radius: 2px;
  background: rgba(7, 6, 14, 0.6);
  font-family: var(--font-mono);
  font-size: var(--step-1);
  letter-spacing: 0.12em;
  color: var(--muted);
}

/* ---------- 11. Media containers (图片占位基础) ---------- */
.media {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background:
    radial-gradient(120% 90% at 20% 0%, rgba(124, 58, 237, 0.35), transparent 60%),
    linear-gradient(150deg, #1A1730, #0B0916);
}
.media > img,
.media > picture > img,
.media > video {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.media::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, transparent 55%, rgba(7, 6, 14, 0.72));
  pointer-events: none;
  z-index: 1;
}
.media--square { aspect-ratio: 1 / 1; }
.media--tall { aspect-ratio: 3 / 4; }
.media--wide { aspect-ratio: 21 / 9; }

.media__tag {
  position: absolute;
  left: 12px;
  bottom: 12px;
  z-index: 2;
  padding: 3px 8px;
  border: 1px solid rgba(255, 201, 74, 0.4);
  border-radius: 2px;
  background: rgba(7, 6, 14, 0.74);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--gold);
}

/* ---------- 12. Tabs ---------- */
.tabs { margin-top: 24px; }

.tabs__list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding-bottom: 10px;
  margin-bottom: 20px;
  border-bottom: 1px solid var(--line-soft);
}

.tabs__tab {
  padding: 8px 16px;
  border: 1px solid transparent;
  border-radius: 3px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--step-2);
  letter-spacing: 0.05em;
  color: var(--muted);
  transition: color 0.18s var(--ease), background 0.18s var(--ease),
    box-shadow 0.18s var(--ease);
}
.tabs__tab:hover {
  color: var(--paper);
  background: rgba(124, 58, 237, 0.18);
}
.tabs__tab[aria-selected="true"] {
  background: rgba(124, 58, 237, 0.92);
  border-color: var(--purple);
  color: #FFFFFF;
  box-shadow: 0 0 20px rgba(124, 58, 237, 0.45);
}

.tabs__panel { padding-top: 4px; }
.tabs__panel[hidden] { display: none; }

/* ---------- 13. Copy button ---------- */
.copy-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 36px;
  padding: 6px 14px;
  border: 1px dashed rgba(34, 211, 238, 0.5);
  border-radius: 2px;
  background: rgba(34, 211, 238, 0.05);
  font-family: var(--font-mono);
  font-size: var(--step-1);
  letter-spacing: 0.08em;
  color: var(--blue);
  transition: background 0.18s var(--ease), border-color 0.18s var(--ease),
    color 0.18s var(--ease);
}
.copy-btn:hover {
  background: rgba(34, 211, 238, 0.14);
  border-style: solid;
}
.copy-btn[data-copied="true"] {
  border-color: rgba(255, 201, 74, 0.7);
  background: rgba(255, 201, 74, 0.1);
  color: var(--gold);
}

/* ---------- 14. Reveal ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 0.34s var(--ease), transform 0.34s var(--ease);
  transition-delay: calc(var(--reveal-step, 0) * 40ms);
}
[data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

/* ---------- 15. Responsive ---------- */
@media (max-width: 1080px) {
  .footer__grid { grid-template-columns: 1.2fr 1fr 1fr; }
  .footer__col--brand { grid-column: 1 / -1; max-width: none; }
}

@media (max-width: 900px) {
  .footer__grid { grid-template-columns: 1fr 1fr; }
  .grid--rail { grid-auto-columns: minmax(240px, 1fr); }
}

@media (max-width: 880px) {
  .site-header { position: static; }

  .site-header__inner { padding-top: 10px; gap: 6px; }

  .masthead__coord {
    font-size: 11px;
    letter-spacing: 0.12em;
  }
  .masthead__coord-item--dim { display: none; }

  .brand__sub { letter-spacing: 0.24em; }

  .nav-toggle { display: inline-flex; margin: 0 auto; }

  .nav {
    display: none;
    width: 100%;
    margin-top: 6px;
    padding-top: 8px;
    border-top: 1px solid var(--line-soft);
  }
  .nav[data-open] {
    display: block;
    animation: navDrop 0.22s var(--ease);
  }

  .nav__list {
    flex-direction: column;
    flex-wrap: nowrap;
    width: 100%;
    gap: 2px;
    padding-bottom: 4px;
  }

  .nav__link {
    width: 100%;
    justify-content: flex-start;
    padding: 12px 14px;
    font-size: 15px;
    border: 1px solid transparent;
  }
  .nav__link::after { display: none; }

  .nav__link[aria-current="page"] {
    background: rgba(34, 211, 238, 0.1);
    border-color: rgba(34, 211, 238, 0.35);
  }
  .nav__link[aria-current="page"]::before {
    content: "";
    position: absolute;
    left: 0;
    top: 10px;
    bottom: 10px;
    width: 3px;
    border-radius: 2px;
    background: var(--blue);
    box-shadow: 0 0 10px var(--blue);
  }
}

@keyframes navDrop {
  from { opacity: 0; transform: translateY(-6px); }
  to { opacity: 1; transform: none; }
}

@media (max-width: 640px) {
  :root { --gutter: 16px; }

  .section { padding: 40px 0; }

  .btn { width: 100%; }
  .btn-row { gap: 12px; }

  .footer__grid { grid-template-columns: 1fr; }
  .footer__bottom { flex-direction: column; align-items: flex-start; }

  .tabs__tab { flex: 1 1 auto; text-align: center; }
}

@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;
    transition: none;
  }

  .card:hover,
  .btn:hover {
    transform: none;
  }
}