:root {
  color-scheme: dark;
  --ink: #eef3fa;
  --muted: #8b97a6;
  --dim: #5e6977;
  --line: rgba(181, 198, 219, 0.16);
  --line-strong: rgba(181, 198, 219, 0.29);
  --accent: #72a7ff;
  --accent-strong: #3f7de8;
  --accent-rgb: 114, 167, 255;
  --surface: #080b0f;
  --surface-raised: #0c1117;
  --panel: #10161e;
  --section-x: clamp(24px, 5.5vw, 88px);
  font-family: "Inter", ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: var(--surface);
  color: var(--ink);
  font-synthesis: none;
  scroll-behavior: smooth;
}

:root[data-theme="light"] {
  color-scheme: light;
  --ink: #111820;
  --muted: #5c6876;
  --dim: #7a8592;
  --line: rgba(29, 45, 63, 0.15);
  --line-strong: rgba(29, 45, 63, 0.27);
  --accent: #2868d8;
  --accent-strong: #1557c5;
  --accent-rgb: 40, 104, 216;
  --surface: #f5f7f9;
  --surface-raised: #edf1f5;
  --panel: #ffffff;
}

* { box-sizing: border-box; }

html, body { min-width: 320px; margin: 0; background: var(--surface); }
body { overflow-x: hidden; }
a { color: inherit; text-decoration: none; }
button, a { -webkit-tap-highlight-color: transparent; }

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: fixed;
  z-index: 100;
  top: 12px;
  left: 12px;
  padding: 10px 14px;
  color: var(--surface);
  background: var(--ink);
  transform: translateY(-150%);
}

.skip-link:focus { transform: translateY(0); }

.site-header {
  position: absolute;
  z-index: 20;
  inset: 0 0 auto;
  height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--section-x);
  border-bottom: 1px solid var(--line);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 14px;
  font-weight: 680;
  letter-spacing: 0;
}

.brand img { width: 25px; height: 25px; border-radius: 6px; }
.site-header nav { display: flex; align-items: center; gap: 26px; }

.site-header nav a {
  color: var(--muted);
  font-size: 12px;
  transition: color 150ms ease;
}

.site-header nav a:hover,
.site-header .nav-download { color: var(--ink); }

.theme-toggle {
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  padding: 0;
  color: var(--muted);
  background: transparent;
  border: 1px solid var(--line-strong);
  border-radius: 2px;
  cursor: pointer;
  transition: color 150ms ease, border-color 150ms ease, background 150ms ease;
}

.theme-toggle:hover { color: var(--ink); border-color: var(--accent); background: rgba(var(--accent-rgb), 0.08); }
.theme-toggle:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }
.theme-toggle svg { width: 16px; fill: none; stroke: currentColor; stroke-linecap: round; stroke-linejoin: round; stroke-width: 1.6; }
.theme-toggle .theme-sun { display: none; }
:root[data-theme="light"] .theme-toggle .theme-sun { display: initial; }
:root[data-theme="light"] .theme-toggle .theme-moon { display: none; }

.hero {
  position: relative;
  min-height: min(820px, 100svh);
  display: flex;
  align-items: center;
  padding: 116px var(--section-x) 70px;
  isolation: isolate;
  overflow: hidden;
}
.hero-photo { position: absolute; z-index: -3; inset: 0; width: 100%; height: 100%; object-fit: cover; object-position: 62% center; transform: scale(1.025) translate3d(var(--hero-x, 0), var(--hero-y, 0), 0); transition: transform 700ms ease; }
.hero-shade { position: absolute; z-index: -2; inset: 0; pointer-events: none; background: linear-gradient(90deg, #080b0ff5 0%, #080b0fe8 28%, #080b0f75 52%, #080b0f0d 78%); }
:root[data-theme="light"] .hero-shade { background: linear-gradient(90deg, #f5f7f9fa 0%, #f5f7f9eb 28%, #f5f7f960 52%, #f5f7f900 78%); }
.hero .hero-copy { max-width: 530px; }
.hero .hero-detail { max-width: 440px; }
.hero .release-note { max-width: 410px; font-size: 12px; line-height: 1.5; color: var(--muted); }
.site-header { background: var(--surface); }

.hero-copy { position: relative; z-index: 2; }

.technical-label,
.node-id,
.step-number {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

.technical-label {
  margin: 0 0 22px;
  color: var(--accent);
  font-size: 10px;
  font-weight: 650;
  letter-spacing: 0.15em;
  text-transform: uppercase;
}

.hero h1 {
  margin: 0;
  font-size: clamp(58px, 7.2vw, 112px);
  line-height: 0.9;
  letter-spacing: -0.015em;
  font-weight: 690;
}

.hero-promise {
  max-width: 620px;
  margin: 34px 0 0;
  font-size: clamp(27px, 3vw, 45px);
  line-height: 1.05;
  letter-spacing: -0.01em;
  font-weight: 550;
}

.hero-detail {
  max-width: 470px;
  margin: 22px 0 0;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.6;
}

.hero-actions { display: flex; align-items: center; gap: 22px; margin-top: 32px; }

.download-button {
  min-height: 48px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 26px;
  padding: 0 18px;
  color: #07101d;
  background: #edf4ff;
  border: 1px solid #edf4ff;
  border-radius: 2px;
  font-size: 12px;
  font-weight: 680;
  transition: color 150ms ease, background 150ms ease, border-color 150ms ease, transform 150ms ease;
}

.download-button svg { width: 17px; fill: none; stroke: currentColor; stroke-linecap: round; stroke-linejoin: round; stroke-width: 1.6; }
.download-button:not([aria-disabled="true"]):hover { background: var(--accent); border-color: var(--accent); transform: translateY(-2px); }
.download-button[aria-disabled="true"] { color: var(--dim); background: var(--panel); border-color: var(--line); cursor: not-allowed; }

.text-link {
  padding: 9px 0;
  color: var(--muted);
  border-bottom: 1px solid var(--line-strong);
  font-size: 12px;
  transition: color 150ms ease, border-color 150ms ease;
}

.text-link:hover { color: var(--ink); border-color: var(--accent); }
.release-note { margin: 13px 0 0; color: var(--dim); font-size: 10px; }

.hero-enter { opacity: 0; transform: translateY(16px); animation: hero-in 560ms cubic-bezier(.2,.75,.2,1) forwards; }
.hero-copy .hero-enter:nth-child(2) { animation-delay: 70ms; }
.hero-copy .hero-enter:nth-child(3) { animation-delay: 130ms; }
.hero-copy .hero-enter:nth-child(4) { animation-delay: 190ms; }
.hero-copy .hero-enter:nth-child(5) { animation-delay: 250ms; }
.hero-copy .hero-enter:nth-child(6) { animation-delay: 310ms; }


.section-pad { padding: clamp(82px, 10vw, 140px) var(--section-x); }
.system, .requirements { background: var(--surface-raised); }
.setup, .faq { background: var(--surface); }

.section-heading {
  display: grid;
  grid-template-columns: 0.55fr 1.2fr 0.75fr;
  gap: clamp(30px, 6vw, 100px);
  align-items: start;
}

.section-heading.compact { grid-template-columns: 0.55fr 1.95fr; }
.system .section-heading h2 { font-size: clamp(42px, 4.15vw, 64px); }
.section-heading h2, .download h2 {
  margin: 0;
  max-width: 900px;
  font-size: clamp(42px, 6vw, 88px);
  font-weight: 580;
  letter-spacing: -0.015em;
  line-height: 0.98;
}

.section-heading > p:last-child {
  margin: 4px 0 0;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.65;
}

.node-id { color: var(--accent); font-size: 10px; letter-spacing: 0.08em; }
.connection-list { margin-top: 64px; border-top: 1px solid var(--line-strong); }
.connection-row { display: grid; grid-template-columns: 1fr 1.2fr; gap: 60px; padding: 36px 0; border-bottom: 1px solid var(--line); }
.connection-row h3 { margin: 14px 0 0; font-size: clamp(28px, 3vw, 42px); font-weight: 550; letter-spacing: -0.025em; }
.connection-row p { max-width: 620px; margin: 0 0 12px; color: var(--muted); font-size: 15px; line-height: 1.65; }
.connection-row strong { color: var(--ink); font-weight: 550; }
.connection-row .text-link { display: inline-block; margin-top: 8px; color: var(--accent); }
.section-note { max-width: 750px; margin: 32px 0 0 auto; color: var(--muted); font-size: 14px; line-height: 1.7; }
.section-note a, .preview-note a { text-decoration: underline; text-underline-offset: 4px; }
.receiver-download { display: flex; justify-content: space-between; align-items: center; gap: 30px; margin-top: 55px; padding: 32px 0; border-top: 1px solid #ffffff40; border-bottom: 1px solid #ffffff40; }
.receiver-download .node-id { color: #b8d1ff; }
.receiver-download h3 { margin: 12px 0; font-size: 26px; font-weight: 550; }
.receiver-download p { max-width: 600px; margin: 8px 0 0; color: #c8d9f8; font-size: 14px; line-height: 1.6; }
.download .release-note { color: #d5e4ff; }
a:focus-visible, button:focus-visible, summary:focus-visible { outline: 2px solid var(--accent); outline-offset: 5px; }
.download a:focus-visible { outline-color: white; }

.requirements-list { display: grid; grid-template-columns: repeat(2, 1fr); margin: 68px 0 0; border-top: 1px solid var(--line-strong); }
.requirements-list div { display: grid; grid-template-columns: 0.75fr 1.25fr; gap: 24px; padding: 19px 0; border-bottom: 1px solid var(--line); }
.requirements-list div:nth-child(odd) { padding-right: 32px; }
.requirements-list div:nth-child(even) { padding-left: 32px; border-left: 1px solid var(--line); }
.requirements-list dt { color: var(--dim); font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 9px; letter-spacing: 0.07em; text-transform: uppercase; }
.requirements-list dd { margin: 0; font-size: 13px; }

.steps { margin: 78px 0 0 27.5%; padding: 0; list-style: none; border-top: 1px solid var(--line-strong); }
.steps li { display: grid; grid-template-columns: 70px 1fr; gap: 20px; padding: 29px 0; border-bottom: 1px solid var(--line); }
.step-number { padding-top: 5px; color: var(--accent); font-size: 10px; }
.steps h3 { margin: 0; font-size: clamp(21px, 2vw, 30px); font-weight: 560; letter-spacing: 0; }
.steps p { max-width: 620px; margin: 9px 0 0; color: var(--muted); font-size: 14px; line-height: 1.6; }
.steps strong { color: var(--ink); font-weight: 620; }

.requirements-list { margin-top: 82px; }
.security-note { display: grid; grid-template-columns: 0.55fr 1.95fr; gap: clamp(30px, 6vw, 100px); margin-top: 70px; padding-top: 26px; border-top: 1px solid var(--accent); }
.security-note p:last-child { max-width: 720px; margin: 0; color: var(--muted); font-size: 16px; line-height: 1.65; }

.faq-list { margin: 78px 0 0 27.5%; border-top: 1px solid var(--line-strong); }
.faq-list details { padding: 24px 0; border-bottom: 1px solid var(--line); }
.faq-list summary { cursor: pointer; font-size: clamp(18px, 2vw, 27px); font-weight: 550; letter-spacing: 0; }
.faq-list summary::marker { color: var(--accent); }
.faq-list p { max-width: 720px; margin: 15px 0 0; color: var(--muted); font-size: 14px; line-height: 1.65; }

.download { min-height: 580px; background: #174fae; color: #f5f8ff; }
.download .technical-label { color: #b8d1ff; }
.download-copy { max-width: 540px; margin: 28px 0 0; color: #c8d9f8; font-size: 16px; line-height: 1.6; }
.download-row { display: flex; align-items: center; gap: 24px; margin-top: 40px; }
.download-button.large { min-width: 250px; min-height: 54px; }
.download .download-button[aria-disabled="true"] { color: #93afd9; background: rgba(8, 28, 62, 0.35); border-color: rgba(213, 228, 255, 0.22); }
.release-meta { display: flex; flex-direction: column; gap: 5px; color: #b8ccef; font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 9px; }
.release-details { max-width: 720px; margin-top: 38px; padding-top: 17px; border-top: 1px solid rgba(220, 232, 255, 0.25); }
.release-details summary { width: fit-content; cursor: pointer; font-size: 12px; font-weight: 650; }
.release-details p { max-width: 640px; color: #c0d2f2; font-size: 12px; line-height: 1.6; }

footer {
  min-height: 130px;
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  align-items: center;
  padding: 28px var(--section-x);
  color: var(--dim);
  background: var(--surface);
  border-top: 1px solid var(--line);
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 9px;
  text-transform: uppercase;
}

footer p:nth-of-type(1) { text-align: center; }
footer p:last-child { text-align: right; }
.reveal { opacity: 0; transform: translateY(22px); transition: opacity 560ms ease, transform 560ms cubic-bezier(.2,.75,.2,1); }
.reveal.is-visible { opacity: 1; transform: translateY(0); }

@keyframes hero-in { to { opacity: 1; transform: translateY(0); } }
@media (max-width: 1080px) {
  .section-heading { grid-template-columns: 0.4fr 1.05fr 0.65fr; gap: 32px; }
  .hero .hero-copy { max-width: 470px; }
}
@media (max-width: 840px) {
  .site-header { height: 64px; }
  .site-header nav { gap: 14px; }
  .site-header nav a:not(.nav-download) { display: none; }
  .hero { min-height: min(850px, 100svh); align-items: flex-start; padding: 112px var(--section-x) 240px; }
  .hero-photo { object-position: 74% center; }
  .hero-shade { background: linear-gradient(180deg, #080b0ff5 0%, #080b0fe0 40%, #080b0f30 80%); }
  :root[data-theme="light"] .hero-shade { background: linear-gradient(180deg, #f5f7f9fa 0%, #f5f7f9e0 40%, #f5f7f920 80%); }
  .section-heading, .section-heading.compact { grid-template-columns: 1fr; gap: 18px; }
  .section-heading > p:last-child { max-width: 620px; }
  .steps, .faq-list { margin-left: 0; }
  .connection-row { gap: 32px; }
  .security-note { grid-template-columns: 1fr; gap: 12px; }
  .requirements-list { grid-template-columns: 1fr; }
  .requirements-list div:nth-child(n) { padding: 20px 0; border-left: 0; }
}
@media (max-width: 590px) {
  .hero { padding-top: 100px; padding-bottom: 180px; min-height: 100svh; }
  .hero h1 { font-size: clamp(53px, 14vw, 76px); }
  .hero-promise { font-size: 32px; margin-top: 24px; }
  .hero-detail { font-size: 14px; margin-top: 18px; }
  .hero-actions { gap: 20px; margin-top: 24px; flex-wrap: wrap; }
  .hero-photo { object-position: 71% bottom; }
  .connection-row { grid-template-columns: 1fr; gap: 22px; }
  .steps li { grid-template-columns: 35px 1fr; gap: 12px; }
  .download-row, .receiver-download { align-items: flex-start; flex-direction: column; }
  footer { grid-template-columns: 1fr; gap: 16px; padding-top: 40px; padding-bottom: 40px; }
  footer p:nth-of-type(1), footer p:last-child { text-align: left; }
}
@media (prefers-reduced-motion: reduce) {
  :root { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
  .hero-enter, .reveal { opacity: 1; transform: none; }
}

.sender-label { margin: 36px 0 -20px; color: #b8d1ff; }