:root {
  --deep-abyss: #061A2B;
  --ocean-800: #0B2F45;
  --ocean-600: #125873;
  --cyan: #16D9D0;
  --ice-cyan: #8EF4EC;
  --coral: #FF6B4A;
  --sand: #D9C08C;
  --mist: #F3F7F8;
  --slate: #263640;
  --white: #FFFFFF;

  --hairline: rgba(255, 255, 255, 0.13);
  --hairline-warm: rgba(217, 192, 140, 0.28);

  --font-display: "HarmonyOS Sans SC", "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-body: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", "Roboto Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  --shell: 1280px;
  --gutter: clamp(20px, 4.2vw, 64px);
  --radius: 16px;
  --radius-sm: 10px;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --header-h: 78px;
}

@media (max-width: 700px) {
  :root { --header-h: 66px; }
}

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

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 20px);
}

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

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

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

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

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

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

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background-color: var(--deep-abyss);
  background-image:
    radial-gradient(1100px 620px at 84% -10%, rgba(22, 217, 208, 0.13), transparent 62%),
    radial-gradient(820px 540px at 2% 6%, rgba(18, 88, 115, 0.42), transparent 66%);
  background-repeat: no-repeat;
  color: rgba(255, 255, 255, 0.82);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.8;
  letter-spacing: 0.01em;
}

#main-content { display: block; flex: 1 0 auto; }

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: var(--white);
}

strong, b { font-weight: 700; color: var(--white); }

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

.surface {
  background-color: var(--deep-abyss);
  color: rgba(255, 255, 255, 0.82);
}

.surface--ocean {
  background-color: var(--ocean-800);
  background-image: radial-gradient(900px 520px at 88% 0%, rgba(22, 217, 208, 0.1), transparent 70%);
  color: rgba(255, 255, 255, 0.82);
}

.surface--light {
  background-color: var(--mist);
  background-image: radial-gradient(760px 420px at 92% 0%, rgba(22, 217, 208, 0.09), transparent 72%);
  color: var(--slate);
}

.surface--light h1,
.surface--light h2,
.surface--light h3,
.surface--light h4 { color: var(--deep-abyss); }

.surface--light strong,
.surface--light b { color: var(--deep-abyss); }

/* ---------- Skip link ---------- */
.skip-link {
  position: fixed;
  left: 14px;
  top: 14px;
  z-index: 200;
  padding: 10px 20px;
  border-radius: 999px;
  background: var(--cyan);
  color: var(--deep-abyss);
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.08em;
  transform: translateY(-180%);
  transition: transform 0.32s var(--ease);
}

.skip-link:focus,
.skip-link:focus-visible {
  transform: translateY(0);
  outline: 2px solid var(--deep-abyss);
  outline-offset: 2px;
}

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 90;
  color: var(--white);
  background-color: transparent;
  transition: background-color 0.38s var(--ease), box-shadow 0.38s var(--ease), backdrop-filter 0.38s var(--ease);
}

.site-header::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(6, 26, 43, 0.8), rgba(6, 26, 43, 0));
  pointer-events: none;
  transition: opacity 0.38s var(--ease);
}

.site-header[data-scrolled]::after { opacity: 0; }

.site-header[data-scrolled] {
  background-color: rgba(6, 26, 43, 0.94);
  -webkit-backdrop-filter: blur(16px) saturate(140%);
  backdrop-filter: blur(16px) saturate(140%);
  box-shadow: 0 1px 0 var(--hairline-warm), 0 26px 50px -34px #000;
}

.site-header__inner {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  gap: clamp(12px, 2vw, 32px);
  min-height: var(--header-h);
}

/* ---------- Brand ---------- */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  flex: 0 0 auto;
  transition: opacity 0.28s var(--ease);
}

.brand:hover { opacity: 0.86; }

.brand__mark {
  position: relative;
  flex: 0 0 auto;
  width: 34px;
  height: 34px;
  border-radius: 52% 46% 54% 44% / 48% 56% 44% 52%;
  background: linear-gradient(148deg, var(--cyan) 8%, var(--ocean-600) 58%, var(--ice-cyan) 100%);
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.3), 0 10px 22px -14px var(--cyan);
}

.brand__mark::before {
  content: "";
  position: absolute;
  right: -7px;
  top: 50%;
  width: 13px;
  height: 13px;
  background: var(--cyan);
  opacity: 0.82;
  transform: translateY(-50%);
  clip-path: polygon(0 0, 100% 50%, 0 100%);
}

.brand__text {
  display: grid;
  gap: 2px;
  line-height: 1.15;
}

.brand__name {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 18px;
  letter-spacing: 0.05em;
  color: var(--white);
}

.brand__desc {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.16em;
  color: var(--ice-cyan);
  opacity: 0.85;
  white-space: nowrap;
}

/* ---------- Navigation ---------- */
.site-nav { margin-inline-start: auto; }

.site-nav__list {
  display: flex;
  align-items: center;
  gap: clamp(10px, 1.5vw, 22px);
  counter-reset: navindex;
}

.site-nav__link {
  position: relative;
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  padding: 8px 2px 11px;
  font-size: 14px;
  font-weight: 500;
  color: rgba(255, 255, 255, 0.72);
  white-space: nowrap;
  transition: color 0.28s var(--ease);
}

.site-nav__link::before {
  counter-increment: navindex;
  content: counter(navindex, decimal-leading-zero) / "";
  font-family: var(--font-mono);
  font-size: 9.5px;
  letter-spacing: 0.08em;
  color: var(--cyan);
  opacity: 0.5;
  transform: translateY(-3px);
  transition: opacity 0.28s var(--ease), color 0.28s var(--ease);
}

.site-nav__link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1.5px;
  background: var(--cyan);
  transform: scaleX(0);
  transform-origin: 0 50%;
  transition: transform 0.34s var(--ease), background 0.34s var(--ease);
}

.site-nav__link:hover,
.site-nav__link:focus-visible { color: var(--white); }

.site-nav__link:hover::before { opacity: 1; }

.site-nav__link:hover::after { transform: scaleX(1); }

.site-nav__link[aria-current="page"] { color: var(--white); }

.site-nav__link[aria-current="page"]::before {
  opacity: 1;
  color: var(--ice-cyan);
}

.site-nav__link[aria-current="page"]::after {
  transform: scaleX(1);
  background: linear-gradient(90deg, var(--cyan), var(--sand));
}

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

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 22px;
  border: 1px solid transparent;
  border-radius: 999px;
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: 0.04em;
  text-align: center;
  cursor: pointer;
  transition: background-color 0.3s var(--ease), color 0.3s var(--ease),
              border-color 0.3s var(--ease), transform 0.3s var(--ease),
              box-shadow 0.3s var(--ease);
}

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

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

.btn--coral {
  background-color: var(--coral);
  border-color: var(--coral);
  color: #2A0B03;
  box-shadow: 0 16px 30px -20px rgba(255, 107, 74, 0.95);
}

.btn--coral:hover {
  background-color: #FF866A;
  border-color: #FF866A;
  box-shadow: 0 18px 34px -18px rgba(255, 107, 74, 0.7);
}

.btn--ghost {
  background-color: rgba(255, 255, 255, 0.05);
  border-color: rgba(255, 255, 255, 0.28);
  color: var(--white);
}

.btn--ghost:hover {
  background-color: rgba(22, 217, 208, 0.12);
  border-color: var(--cyan);
  color: var(--ice-cyan);
}

.btn--cyan {
  background-color: var(--cyan);
  border-color: var(--cyan);
  color: #04222A;
}

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

.btn--sm { padding: 8px 16px; font-size: 13px; }

/* ---------- Nav toggle ---------- */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  border: 1px solid rgba(255, 255, 255, 0.26);
  border-radius: 999px;
  background-color: rgba(255, 255, 255, 0.06);
  color: var(--white);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.06em;
  cursor: pointer;
  transition: border-color 0.3s var(--ease), color 0.3s var(--ease), background-color 0.3s var(--ease);
}

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

.nav-toggle[aria-expanded="true"] {
  border-color: var(--cyan);
  background-color: rgba(22, 217, 208, 0.14);
  color: var(--ice-cyan);
}

.nav-toggle__bars {
  display: grid;
  gap: 4px;
  width: 18px;
}

.nav-toggle__bars span {
  display: block;
  height: 1.5px;
  background-color: currentColor;
  border-radius: 1px;
  transition: transform 0.3s var(--ease), opacity 0.3s var(--ease);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:first-child {
  transform: translateY(2.75px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:last-child {
  transform: translateY(-2.75px) rotate(-45deg);
}

/* ---------- Scroll progress ---------- */
.scroll-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background-color: rgba(255, 255, 255, 0.06);
  overflow: hidden;
  pointer-events: none;
}

.scroll-progress__bar {
  display: block;
  width: 100%;
  height: 100%;
  transform: scaleX(var(--progress, 0));
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--cyan), var(--ice-cyan) 62%, var(--sand));
  transition: transform 0.12s linear;
}

/* ---------- Footer ---------- */
.site-footer {
  position: relative;
  overflow: hidden;
  margin-top: clamp(64px, 9vw, 128px);
  background-image: linear-gradient(180deg, var(--ocean-800), var(--deep-abyss) 64%);
  background-color: var(--deep-abyss);
  border-top: 1px solid var(--hairline-warm);
  color: rgba(255, 255, 255, 0.72);
}

.site-footer::before {
  content: "";
  position: absolute;
  top: -400px;
  right: -300px;
  width: 800px;
  height: 800px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(22, 217, 208, 0.2), transparent 68%);
  pointer-events: none;
}

.site-footer::after {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: min(38%, 460px);
  height: 1px;
  background: linear-gradient(90deg, var(--sand), rgba(217, 192, 140, 0));
  pointer-events: none;
}

.footer__grid {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
  gap: clamp(32px, 5vw, 76px);
  padding-block: clamp(48px, 6vw, 84px) clamp(28px, 3.6vw, 46px);
}

.footer__brand {
  display: grid;
  align-content: start;
  gap: 18px;
  max-width: 46ch;
}

.footer__intro {
  font-size: 15px;
  line-height: 1.85;
  color: rgba(255, 255, 255, 0.64);
}

.footer__contact {
  display: grid;
  gap: 7px;
  font-style: normal;
  margin-top: 4px;
}

.footer__contact-item {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  line-height: 1.7;
  letter-spacing: 0.03em;
  color: rgba(255, 255, 255, 0.76);
}

.footer__contact-item::before {
  content: "";
  flex: 0 0 auto;
  width: 12px;
  height: 1px;
  margin-top: 0.85em;
  background-color: var(--cyan);
  opacity: 0.7;
}

.footer__cols {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: clamp(20px, 3vw, 44px);
}

.footer__col {
  display: grid;
  align-content: start;
  gap: 14px;
}

.footer__col-title {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.2em;
  color: var(--sand);
  line-height: 1.4;
}

.footer__links {
  display: grid;
  gap: 2px;
}

.footer__link {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 6px 0;
  font-size: 14.5px;
  color: rgba(255, 255, 255, 0.72);
  transition: color 0.26s var(--ease);
}

.footer__link::before {
  content: "";
  flex: 0 0 auto;
  width: 12px;
  height: 1px;
  background-color: currentColor;
  opacity: 0.32;
  transition: opacity 0.26s var(--ease), background-color 0.26s var(--ease);
}

.footer__link:hover,
.footer__link:focus-visible { color: var(--ice-cyan); }

.footer__link:hover::before {
  opacity: 1;
  background-color: var(--cyan);
}

.footer__meta {
  position: relative;
  z-index: 1;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 28px;
  padding-block: 20px 36px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer__legal,
.footer__copyright {
  font-family: var(--font-mono);
  font-size: 11.5px;
  line-height: 1.7;
  letter-spacing: 0.06em;
  color: rgba(255, 255, 255, 0.5);
}

/* ---------- Back to top ---------- */
.to-top {
  position: fixed;
  right: clamp(14px, 3vw, 32px);
  bottom: clamp(14px, 3vw, 32px);
  z-index: 80;
  display: inline-grid;
  place-items: center;
  width: 46px;
  height: 46px;
  border-radius: 50%;
  border: 1px solid rgba(142, 244, 236, 0.4);
  background-color: rgba(11, 47, 69, 0.92);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  color: var(--ice-cyan);
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(14px);
  transition: opacity 0.3s var(--ease), transform 0.3s var(--ease),
              visibility 0.3s var(--ease), border-color 0.3s var(--ease),
              background-color 0.3s var(--ease), color 0.3s var(--ease);
}

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

.to-top:hover {
  border-color: var(--coral);
  background-color: rgba(255, 107, 74, 0.18);
  color: var(--white);
}

.to-top__arrow {
  width: 12px;
  height: 12px;
  border-left: 1.5px solid currentColor;
  border-top: 1.5px solid currentColor;
  transform: rotate(45deg);
}

/* ---------- Typographic utilities ---------- */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--cyan);
}

.eyebrow::before {
  content: "";
  width: 26px;
  height: 1px;
  background-color: currentColor;
  opacity: 0.72;
}

.index-no {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(28px, 4vw, 48px);
  font-weight: 400;
  line-height: 1;
  letter-spacing: 0.06em;
  color: transparent;
  -webkit-text-stroke: 1px rgba(22, 217, 208, 0.55);
}

.index-no--solid {
  color: var(--cyan);
  -webkit-text-stroke: 0;
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  border: 1px solid rgba(22, 217, 208, 0.34);
  border-radius: 999px;
  background-color: rgba(22, 217, 208, 0.1);
  color: var(--ice-cyan);
  font-family: var(--font-mono);
  font-size: 11px;
  line-height: 1.6;
  letter-spacing: 0.1em;
  white-space: nowrap;
}

.surface--light .chip {
  border-color: rgba(18, 88, 115, 0.28);
  background-color: rgba(18, 88, 115, 0.08);
  color: var(--ocean-600);
}

/* ---------- Breadcrumbs ---------- */
.breadcrumbs {
  --bc-muted: rgba(255, 255, 255, 0.5);
  --bc-strong: var(--white);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.08em;
  color: var(--bc-muted);
}

.breadcrumbs--light {
  --bc-muted: rgba(6, 26, 43, 0.5);
  --bc-strong: var(--deep-abyss);
}

.breadcrumbs ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}

.breadcrumbs li {
  display: flex;
  align-items: center;
  gap: 8px;
}

.breadcrumbs li + li::before {
  content: "/";
  color: var(--bc-muted);
  opacity: 0.7;
}

.breadcrumbs a {
  color: var(--bc-muted);
  transition: color 0.25s var(--ease);
}

.breadcrumbs a:hover,
.breadcrumbs a:focus-visible { color: var(--cyan); }

.breadcrumbs [aria-current="page"] { color: var(--bc-strong); }

/* ---------- Layout grids ---------- */
.grid {
  display: grid;
  gap: clamp(20px, 3vw, 40px);
}

.grid--7-5 { grid-template-columns: minmax(0, 7fr) minmax(0, 5fr); }
.grid--8-4 { grid-template-columns: minmax(0, 8fr) minmax(0, 4fr); }
.grid--3-6-3 { grid-template-columns: minmax(0, 3fr) minmax(0, 6fr) minmax(0, 3fr); }

/* ---------- Prose ---------- */
.prose {
  max-width: 68ch;
  font-size: 17px;
  line-height: 1.85;
}

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

.prose h2,
.prose h3 {
  font-family: var(--font-display);
  line-height: 1.25;
  letter-spacing: -0.01em;
  margin-top: 2em;
}

.prose h2 { font-size: clamp(24px, 2.6vw, 32px); }
.prose h3 { font-size: clamp(19px, 2vw, 23px); }

.prose ul,
.prose ol {
  padding-left: 1.35em;
  list-style: disc;
}

.prose ol { list-style: decimal; }

.prose li + li { margin-top: 0.42em; }

.prose a {
  color: var(--cyan);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

.surface--light .prose a { color: var(--ocean-600); }

.prose blockquote {
  padding-left: 18px;
  border-left: 2px solid var(--sand);
  color: inherit;
  opacity: 0.82;
}

/* ---------- Panel ---------- */
.panel {
  position: relative;
  padding: clamp(20px, 2.6vw, 32px);
  border: 1px solid var(--hairline);
  border-radius: var(--radius);
  background-color: rgba(11, 47, 69, 0.55);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
}

.panel--solid {
  background-color: var(--white);
  border-color: rgba(6, 26, 43, 0.08);
  color: var(--slate);
  -webkit-backdrop-filter: none;
  backdrop-filter: none;
  box-shadow: 0 26px 64px -44px rgba(6, 26, 43, 0.8);
}

.panel--solid h2,
.panel--solid h3 { color: var(--deep-abyss); }

.panel--outline {
  background-color: transparent;
  border-color: var(--hairline-warm);
}

/* ---------- Media frame ---------- */
.media-frame {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  aspect-ratio: 16 / 10;
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius);
  background-color: var(--ocean-800);
  background-image: linear-gradient(140deg, var(--ocean-600), var(--ocean-800) 55%, var(--deep-abyss));
}

.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  background-image:
    radial-gradient(120% 82% at 18% 8%, rgba(22, 217, 208, 0.26), transparent 58%),
    repeating-radial-gradient(circle at 80% 116%, rgba(142, 244, 236, 0.16) 0 1px, transparent 1px 26px);
  opacity: 0.85;
  pointer-events: none;
  transition: opacity 0.5s var(--ease), transform 0.6s var(--ease);
}

.media-frame:hover::after { opacity: 1; transform: scale(1.04); }

.media-frame > img,
.media-frame > picture,
.media-frame > picture img {
  position: relative;
  z-index: 1;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

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

/* ---------- Divider ---------- */
.divider {
  height: 1px;
  border: 0;
  margin-block: clamp(28px, 4vw, 52px);
  background-image: linear-gradient(90deg, rgba(217, 192, 140, 0.5), rgba(255, 255, 255, 0.06) 42%, transparent);
}

.surface--light .divider {
  background-image: linear-gradient(90deg, rgba(6, 26, 43, 0.22), rgba(6, 26, 43, 0.04) 42%, transparent);
}

/* ---------- Expandable group ---------- */
.expand {
  border: 1px solid var(--hairline);
  border-radius: var(--radius-sm);
  background-color: rgba(255, 255, 255, 0.03);
  overflow: hidden;
  transition: border-color 0.3s var(--ease), background-color 0.3s var(--ease);
}

.expand + .expand { margin-top: 10px; }

.expand[data-open] {
  border-color: rgba(22, 217, 208, 0.45);
  background-color: rgba(22, 217, 208, 0.05);
}

.expand__trigger {
  display: flex;
  width: 100%;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 15px 18px;
  border: 0;
  background: none;
  color: inherit;
  font-family: var(--font-display);
  font-size: 15.5px;
  font-weight: 700;
  line-height: 1.5;
  letter-spacing: 0.01em;
  text-align: left;
  cursor: pointer;
  transition: color 0.25s var(--ease);
}

.expand__trigger:hover { color: var(--ice-cyan); }

.expand__trigger:focus-visible { outline-offset: -3px; }

.expand__sign {
  position: relative;
  flex: 0 0 auto;
  width: 16px;
  height: 16px;
}

.expand__sign::before,
.expand__sign::after {
  content: "";
  position: absolute;
  background-color: var(--cyan);
  border-radius: 1px;
  transition: transform 0.3s var(--ease), opacity 0.3s var(--ease);
}

.expand__sign::before { left: 0; top: 7.25px; width: 16px; height: 1.5px; }
.expand__sign::after { left: 7.25px; top: 0; width: 1.5px; height: 16px; }

.expand[data-open] .expand__sign::after {
  transform: scaleY(0);
  opacity: 0;
}

.expand__panel {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.38s var(--ease);
}

.expand__inner {
  padding: 0 18px 18px;
  font-size: 15.5px;
  line-height: 1.8;
  color: rgba(255, 255, 255, 0.7);
}

.surface--light .expand {
  border-color: rgba(6, 26, 43, 0.12);
  background-color: rgba(255, 255, 255, 0.72);
}

.surface--light .expand[data-open] {
  border-color: rgba(22, 217, 208, 0.6);
  background-color: var(--white);
}

.surface--light .expand__inner { color: rgba(38, 54, 64, 0.78); }

/* ---------- Reveal ---------- */
[data-reveal] {
  transition: opacity 0.6s var(--ease), transform 0.6s var(--ease);
}

html.reveal-ready [data-reveal]:not([data-revealed]) {
  opacity: 0;
  transform: translateY(20px);
}

/* ---------- Responsive ---------- */
@media (max-width: 1080px) {
  .nav-toggle { display: inline-flex; }

  .site-header__actions { margin-inline-start: auto; }

  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    margin: 0;
    padding: 10px var(--gutter) 24px;
    display: none;
    background-color: rgba(6, 26, 43, 0.985);
    -webkit-backdrop-filter: blur(18px);
    backdrop-filter: blur(18px);
    border-top: 1px solid var(--hairline-warm);
    box-shadow: 0 34px 64px -34px #000;
  }

  .site-nav[data-open] { display: block; }

  .site-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }

  .site-nav__link {
    width: 100%;
    padding: 14px 0;
    font-size: 16px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  }

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

  .site-nav__link[aria-current="page"] { color: var(--ice-cyan); }
}

@media (max-width: 900px) {
  .grid--7-5,
  .grid--8-4,
  .grid--3-6-3 { grid-template-columns: minmax(0, 1fr); }

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

  .site-header__actions .btn { padding: 9px 15px; font-size: 13px; }
}

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

  .brand__mark { width: 30px; height: 30px; }
  .brand__name { font-size: 16.5px; }

  .site-header__actions .btn { padding: 8px 12px; font-size: 12.5px; }

  .footer__cols { grid-template-columns: minmax(0, 1fr); gap: 26px; }

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

@media (max-width: 460px) {
  .brand__desc { display: none; }
  .brand { gap: 9px; }
  .brand__mark { width: 27px; height: 27px; }
  .brand__name { font-size: 15.5px; }

  .site-header__inner { gap: 8px; }
  .site-header__actions { gap: 6px; }
  .site-header__actions .btn { padding: 8px 10px; font-size: 12px; }

  .nav-toggle { padding: 8px 10px; }
  .nav-toggle__label { display: none; }

  .to-top { width: 42px; height: 42px; }
}

/* ---------- Reduced motion ---------- */
@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;
    scroll-behavior: auto !important;
  }

  [data-reveal],
  html.reveal-ready [data-reveal]:not([data-revealed]) {
    opacity: 1 !important;
    transform: none !important;
  }

  .media-frame:hover::after { transform: none; }
  .btn:hover { transform: none; }
}