/* VimalinxOS — the boot line becomes a boundary map.
   The flower marks the person who stays present while the system comes online. */

body[data-page="os"] {
  --bg: #03040a;
  --bg-alt: #06070d;
  --bg-card: #080a12;
  --text: #d9dcec;
  --text-secondary: #a0a5b8;
  --text-muted: #777d92;
  --text-light: #4b5062;
  --accent: #4ee7ee;
  --accent-muted: rgba(78, 231, 238, 0.1);
  --border: rgba(217, 220, 236, 0.14);
  --border-light: rgba(217, 220, 236, 0.08);
  --grid-line: rgba(217, 220, 236, 0.035);
  --os-black: #03040a;
  --os-surface: #080a12;
  --os-white: #d9dcec;
  --os-muted: #8a90a4;
  --os-cyan: #4ee7ee;
  --os-blue: #78a7ff;
  --os-purple: #9f81d9;
  --os-line: rgba(217, 220, 236, 0.14);
  --os-ease: cubic-bezier(0.16, 1, 0.3, 1);
  background: var(--os-black);
  color: var(--os-white);
}

body[data-page="os"]::before {
  opacity: 0.28;
}

body[data-page="os"] .nav {
  color: var(--os-white);
}

body[data-page="os"] .nav.scrolled {
  background: rgba(3, 4, 10, 0.82);
  border-color: rgba(217, 220, 236, 0.08);
  backdrop-filter: saturate(130%) blur(18px);
  -webkit-backdrop-filter: saturate(130%) blur(18px);
}

body[data-page="os"] .nav-brand,
body[data-page="os"] .nav-links a:hover,
body[data-page="os"] .nav-links a:focus-visible,
body[data-page="os"] .nav-links .nav-active {
  color: var(--os-white);
}

body[data-page="os"] .nav-links a {
  color: var(--os-muted);
}

body[data-page="os"] .theme-toggle {
  display: none;
}

body[data-page="os"] .footer {
  background: var(--os-black);
  color: var(--os-white);
  border-color: var(--os-line);
}

.os-shell {
  position: relative;
  overflow: clip;
  background:
    linear-gradient(rgba(217, 220, 236, 0.026) 1px, transparent 1px),
    linear-gradient(90deg, rgba(217, 220, 236, 0.026) 1px, transparent 1px),
    var(--os-black);
  background-size: 64px 64px;
  color: var(--os-white);
  font-family: var(--font-sans);
}

.os-shell::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 5;
  pointer-events: none;
  background: linear-gradient(90deg, rgba(3, 4, 10, 0.64), transparent 6%, transparent 94%, rgba(3, 4, 10, 0.64));
}

.os-shell section {
  position: relative;
  z-index: 10;
}

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

.os-kicker,
.os-section-head > span,
.os-feature-meta,
.os-art-label,
.os-boot-state,
.os-map-anchor,
.os-signal-line {
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 500;
  letter-spacing: 0.14em;
  line-height: 1.5;
  text-transform: uppercase;
}

.os-kicker {
  color: var(--os-cyan);
}

.os-page-progress {
  width: 1px;
  position: fixed;
  z-index: 30;
  inset: 92px auto 28px 22px;
  background: rgba(217, 220, 236, 0.1);
  pointer-events: none;
}

.os-page-progress span {
  position: absolute;
  inset: 0;
  transform: scaleY(var(--os-page-progress, 0));
  transform-origin: top;
  background: linear-gradient(180deg, var(--os-cyan), var(--os-blue) 58%, var(--os-purple));
  will-change: transform;
}

/* ---------- Hero / boot identity ---------- */

.os-hero {
  min-height: 100svh;
  padding: 116px clamp(24px, 4vw, 64px) 64px;
  display: grid;
  place-items: center;
  background: var(--os-black);
}

.os-hero::before {
  content: "";
  position: absolute;
  width: min(58vw, 920px);
  aspect-ratio: 1;
  left: 50%;
  top: 42%;
  transform: translate(-50%, -50%);
  border-radius: 50%;
  background: radial-gradient(circle, rgba(120, 167, 255, 0.055), transparent 67%);
  pointer-events: none;
}

.os-boot-lockup {
  width: min(90vw, 430px);
  display: flex;
  flex-direction: column;
  align-items: center;
}

.os-emblem-orbit {
  width: 224px;
  aspect-ratio: 1;
  position: relative;
  display: grid;
  place-items: center;
}

.os-emblem-ring {
  position: absolute;
  border: 1px solid rgba(217, 220, 236, 0.12);
  border-radius: 50%;
}

.os-emblem-ring--outer {
  inset: 0;
}

.os-emblem-ring--inner {
  inset: 16px;
  border-color: rgba(159, 129, 217, 0.2);
}

.os-emblem-ring--outer::after {
  content: "";
  width: 5px;
  height: 5px;
  position: absolute;
  left: 50%;
  top: -3px;
  border-radius: 50%;
  background: var(--os-cyan);
  box-shadow: 0 0 14px rgba(78, 231, 238, 0.7);
}

.os-emblem {
  width: 176px;
  aspect-ratio: 1;
  position: relative;
  overflow: hidden;
  border-radius: 50%;
  background: var(--os-black);
  box-shadow:
    0 0 0 1px rgba(217, 220, 236, 0.12),
    0 18px 48px rgba(0, 0, 0, 0.42);
}

.os-emblem img {
  width: 100%;
  height: 100%;
  display: block;
  object-fit: cover;
  object-position: center;
}

.os-wordmark {
  margin-top: 40px;
  display: inline-flex;
  align-items: baseline;
  color: var(--os-white);
  white-space: nowrap;
}

.os-wordmark span {
  font-size: clamp(42px, 4.4vw, 58px);
  font-weight: 400;
  letter-spacing: 0.015em;
  line-height: 1;
}

.os-wordmark i {
  width: 1px;
  height: 42px;
  margin-inline: 17px 14px;
  position: relative;
  top: 7px;
  background: rgba(217, 220, 236, 0.32);
}

.os-wordmark b {
  color: var(--os-purple);
  font-size: 18px;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: lowercase;
}

.os-boot-rail {
  width: min(100%, 320px);
  height: 2px;
  margin-top: 44px;
  position: relative;
  overflow: hidden;
  background: rgba(217, 220, 236, 0.13);
}

.os-boot-rail span {
  position: absolute;
  inset: 0;
  transform: scaleX(1);
  transform-origin: left;
  background: linear-gradient(90deg, var(--os-cyan), var(--os-blue));
}

.os-boot-state {
  width: min(100%, 320px);
  margin-top: 12px;
  display: flex;
  justify-content: space-between;
  color: var(--os-muted);
  font-size: 8px;
}

.os-feature-copy a svg,
.os-closing > a svg {
  width: 18px;
  height: 18px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.5;
}

/* ---------- Definition / AI OS ---------- */

.os-definition,
.os-boundaries,
.os-vow,
.os-closing {
  width: min(100%, 1520px);
  margin-inline: auto;
  padding-inline: clamp(24px, 6vw, 96px);
}

.os-definition {
  padding-top: clamp(120px, 15vw, 220px);
  padding-bottom: clamp(112px, 14vw, 200px);
}

.os-section-head {
  padding-bottom: 22px;
  display: flex;
  justify-content: space-between;
  gap: 24px;
  border-bottom: 1px solid var(--os-line);
}

.os-section-head > span {
  color: var(--os-muted);
}

.os-definition-grid {
  padding-top: clamp(48px, 7vw, 94px);
  display: grid;
  grid-template-columns: minmax(0, 1.36fr) minmax(280px, 0.64fr);
  align-items: start;
  gap: clamp(48px, 9vw, 140px);
}

.os-definition-thesis > p {
  max-width: 590px;
  margin-top: 32px;
  color: var(--os-muted);
  font-size: clamp(15px, 1.2vw, 18px);
  line-height: 1.8;
}

.os-definition h2,
.os-boundaries-head h2,
.os-vow h2,
.os-closing h2 {
  font-weight: 400;
  letter-spacing: -0.048em;
  line-height: 1.08;
  text-wrap: balance;
}

.os-definition h2 {
  max-width: 900px;
  font-size: clamp(46px, 6vw, 82px);
}

.os-definition-list {
  list-style: none;
  border-top: 1px solid var(--os-line);
}

.os-definition-list li {
  min-height: 84px;
  padding: 18px 0;
  display: grid;
  grid-template-columns: 44px 126px 1fr;
  align-items: start;
  gap: 14px;
  border-bottom: 1px solid var(--os-line);
}

.os-definition-list span,
.os-definition-list b {
  color: var(--os-cyan);
  font-family: var(--font-mono);
  font-size: 9px;
  font-weight: 500;
  letter-spacing: 0.08em;
  line-height: 1.75;
  text-transform: uppercase;
}

.os-definition-list b {
  color: var(--os-white);
}

.os-definition-list p {
  color: var(--os-muted);
  font-size: 13px;
  line-height: 1.7;
}

.os-definition-summary {
  max-width: 840px;
  margin-top: 56px;
  color: var(--os-white);
  font-size: clamp(24px, 2.6vw, 38px);
  font-weight: 400;
  letter-spacing: -0.03em;
  line-height: 1.45;
}

.os-system-map {
  min-height: 176px;
  margin-top: clamp(78px, 10vw, 140px);
  padding: 34px 0 30px;
  display: grid;
  grid-template-columns: minmax(110px, 0.42fr) minmax(260px, 1.4fr) minmax(150px, 0.42fr);
  align-items: center;
  gap: clamp(20px, 5vw, 72px);
  border-block: 1px solid var(--os-line);
}

.os-map-anchor {
  display: flex;
  flex-direction: column;
  gap: 8px;
  color: var(--os-cyan);
}

.os-map-anchor b {
  color: var(--os-muted);
  font-family: var(--font-sans);
  font-size: 13px;
  font-weight: 400;
  letter-spacing: 0;
  text-transform: none;
}

.os-map-anchor--agent {
  align-items: flex-end;
  color: var(--os-purple);
  text-align: right;
}

.os-map-rail {
  height: 1px;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: rgba(217, 220, 236, 0.16);
}

.os-map-rail::before {
  content: "";
  position: absolute;
  inset: -36px 0;
  background:
    linear-gradient(90deg, transparent, rgba(78, 231, 238, 0.035) 50%, transparent),
    repeating-linear-gradient(90deg, transparent 0 79px, rgba(217, 220, 236, 0.045) 80px);
}

.os-map-rail > span {
  position: absolute;
  inset: 0;
  transform: scaleX(var(--os-map-progress, 0));
  transform-origin: left;
  background: linear-gradient(90deg, var(--os-cyan), var(--os-blue), var(--os-purple));
  will-change: transform;
}

.os-map-rail i {
  width: 9px;
  height: 9px;
  z-index: 1;
  border: 1px solid rgba(217, 220, 236, 0.48);
  border-radius: 50%;
  background: var(--os-black);
  box-shadow: 0 0 0 5px var(--os-black);
}

.os-signal-line {
  min-height: 76px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  color: var(--os-muted);
}

.os-signal-line i {
  width: 3px;
  height: 3px;
  flex: 0 0 auto;
  border-radius: 50%;
  background: var(--os-purple);
}

/* ---------- Five boundaries ---------- */

.os-boundaries {
  padding-top: 40px;
  padding-bottom: clamp(120px, 16vw, 220px);
}

.os-boundaries-head {
  align-items: end;
}

.os-boundaries-head > div {
  max-width: 930px;
}

.os-boundaries-head h2 {
  margin-top: 20px;
  font-size: clamp(46px, 6.3vw, 86px);
}

.os-boundaries-head > p {
  max-width: 390px;
  padding-bottom: 8px;
  color: var(--os-muted);
  font-size: 15px;
  line-height: 1.8;
}

.os-feature-grid {
  margin-top: 56px;
}

.os-feature {
  display: grid;
  grid-template-columns: minmax(0, 1.04fr) minmax(340px, 0.96fr);
  border-bottom: 1px solid var(--os-line);
}

.os-feature:first-child {
  border-top: 1px solid var(--os-line);
}

.os-feature-meta {
  min-height: 62px;
  padding: 0 4px;
  grid-column: 1 / -1;
  display: grid;
  grid-template-columns: 74px 1fr auto;
  align-items: center;
  color: var(--os-muted);
  border-bottom: 1px solid var(--os-line);
}

.os-feature-meta > span {
  color: var(--os-cyan);
}

.os-feature-meta b {
  font-weight: 500;
}

.os-feature-meta em {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-style: normal;
}

.os-feature-meta em i {
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--os-cyan);
}

.os-feature-art {
  min-height: clamp(420px, 42vw, 610px);
  position: relative;
  overflow: hidden;
  background:
    linear-gradient(rgba(217, 220, 236, 0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(217, 220, 236, 0.045) 1px, transparent 1px),
    var(--os-surface);
  background-size: 32px 32px;
  border-right: 1px solid var(--os-line);
}

.os-art-label {
  position: absolute;
  z-index: 2;
  left: 24px;
  top: 22px;
  color: var(--os-muted);
  font-size: 8px;
}

.os-feature-art > div {
  transition: transform 420ms var(--os-ease);
}

.os-feature-copy {
  min-width: 0;
  padding: clamp(44px, 6vw, 86px);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 72px;
}

.os-feature-copy h3 {
  font-size: clamp(40px, 4.8vw, 66px);
  font-weight: 400;
  letter-spacing: -0.045em;
  line-height: 1;
  overflow-wrap: anywhere;
}

.os-feature-copy p {
  max-width: 480px;
  color: var(--os-muted);
  font-size: 15px;
  line-height: 1.85;
}

.os-feature-copy a,
.os-closing > a {
  width: fit-content;
  min-height: 48px;
  margin-top: 24px;
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--os-white);
  font-size: 13px;
  transition: color 160ms ease;
}

.os-feature-copy a svg,
.os-closing > a svg {
  color: var(--os-cyan);
  transition: transform 220ms var(--os-ease);
}

.os-feature-copy a:hover,
.os-feature-copy a:focus-visible,
.os-closing > a:hover,
.os-closing > a:focus-visible {
  color: var(--os-cyan);
}

.os-feature-copy a:hover svg,
.os-feature-copy a:focus-visible svg,
.os-closing > a:hover svg,
.os-closing > a:focus-visible svg {
  transform: translateX(4px);
}

.os-feature:nth-child(even) .os-feature-art {
  grid-column: 2;
  grid-row: 2;
  border-right: 0;
  border-left: 1px solid var(--os-line);
}

.os-feature:nth-child(even) .os-feature-copy {
  grid-column: 1;
  grid-row: 2;
}

/* AgentSeat visual */

.feature-seat,
.feature-router,
.feature-pool,
.feature-browser,
.feature-contract {
  position: absolute;
  inset: 0;
}

.feature-window {
  position: absolute;
  inset: 16% 12%;
  border: 1px solid rgba(217, 220, 236, 0.7);
}

.feature-window::before {
  content: "";
  position: absolute;
  inset: 11% 7% auto;
  height: 1px;
  background: rgba(217, 220, 236, 0.72);
  box-shadow:
    0 54px 0 rgba(217, 220, 236, 0.26),
    0 108px 0 rgba(217, 220, 236, 0.16);
}

.feature-window::after {
  content: "";
  width: 32%;
  height: 34%;
  position: absolute;
  right: 11%;
  bottom: 13%;
  border: 1px solid var(--os-cyan);
  background: rgba(78, 231, 238, 0.08);
}

.feature-pointer {
  position: absolute;
  display: grid;
  gap: 9px;
  color: var(--os-white);
  font-family: var(--font-mono);
  font-size: 8px;
  letter-spacing: 0.12em;
}

.feature-pointer::before {
  content: "";
  width: 28px;
  height: 36px;
  display: block;
  clip-path: polygon(0 0, 0 100%, 36% 68%, 56% 100%, 74% 89%, 55% 60%, 100% 60%);
  background: currentColor;
}

.feature-pointer--human {
  left: 23%;
  bottom: 18%;
}

.feature-pointer--agent {
  right: 18%;
  top: 27%;
  color: var(--os-cyan);
}

/* LocalRouter visual */

.feature-router {
  padding: 12%;
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-content: center;
  gap: 16px;
}

.feature-router span,
.feature-router strong {
  min-height: 58px;
  display: grid;
  place-items: center;
  border: 1px solid rgba(217, 220, 236, 0.34);
  color: var(--os-muted);
  font-family: var(--font-mono);
  font-size: 9px;
  font-weight: 500;
  letter-spacing: 0.1em;
}

.feature-router span:nth-child(3) {
  grid-column: 1 / -1;
}

.feature-router strong {
  min-height: 74px;
  grid-column: 1 / -1;
  border-color: rgba(78, 231, 238, 0.58);
  color: var(--os-cyan);
}

.feature-router > i {
  width: 1px;
  height: 34px;
  justify-self: center;
  grid-column: 1 / -1;
  background: linear-gradient(var(--os-cyan), var(--os-blue));
}

/* AgentsPool visual */

.feature-pool {
  background:
    radial-gradient(circle at center, rgba(120, 167, 255, 0.12), transparent 30%),
    linear-gradient(32deg, transparent 49.85%, rgba(217, 220, 236, 0.18) 50%, transparent 50.15%),
    linear-gradient(-32deg, transparent 49.85%, rgba(217, 220, 236, 0.18) 50%, transparent 50.15%);
}

.feature-pool strong,
.feature-pool span {
  position: absolute;
  display: grid;
  place-items: center;
  border: 1px solid rgba(217, 220, 236, 0.58);
  border-radius: 50%;
}

.feature-pool strong {
  width: 126px;
  height: 126px;
  inset: 50% auto auto 50%;
  color: var(--os-blue);
  font-family: var(--font-mono);
  font-size: 9px;
  font-weight: 500;
  letter-spacing: 0.1em;
  transform: translate(-50%, -50%);
}

.feature-pool span {
  width: 16px;
  height: 16px;
  background: var(--os-white);
  box-shadow: 0 0 0 8px var(--os-surface);
}

.feature-pool span:nth-child(1) { left: 16%; top: 24%; }
.feature-pool span:nth-child(2) { right: 14%; top: 31%; }
.feature-pool span:nth-child(3) { left: 28%; bottom: 15%; }

/* AgentBrowser visual */

.feature-browser span {
  width: 54%;
  height: 54%;
  position: absolute;
  border: 1px solid rgba(217, 220, 236, 0.64);
  background: var(--os-surface);
}

.feature-browser span::before {
  content: "•  •  •";
  height: 28px;
  padding-left: 12px;
  display: flex;
  align-items: center;
  border-bottom: 1px solid rgba(217, 220, 236, 0.38);
  color: var(--os-muted);
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.25em;
}

.feature-browser span:nth-child(1) { left: 11%; top: 12%; opacity: 0.25; }
.feature-browser span:nth-child(2) { right: 11%; bottom: 12%; opacity: 0.36; }
.feature-browser span:nth-child(3) { left: 23%; top: 23%; border-color: var(--os-purple); }

.feature-browser strong {
  position: absolute;
  inset: 50% auto auto 50%;
  color: var(--os-purple);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.16em;
  transform: translate(-50%, -50%);
}

/* All2Linux visual */

.feature-contract {
  padding: 7%;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: clamp(20px, 4vw, 64px);
  color: var(--os-white);
  font-size: clamp(30px, 4vw, 60px);
  font-weight: 400;
  letter-spacing: -0.04em;
  line-height: 0.95;
  text-align: center;
}

.feature-contract i {
  color: var(--os-cyan);
  font-style: normal;
}

.feature-contract strong {
  color: var(--os-muted);
  font-weight: 400;
}

/* ---------- Vow and closing ---------- */

.os-vow {
  padding-top: clamp(120px, 15vw, 210px);
  padding-bottom: clamp(120px, 16vw, 230px);
  border-top: 1px solid var(--os-line);
}

.os-vow h2 {
  max-width: 1260px;
  margin-top: 34px;
  font-size: clamp(54px, 7.5vw, 104px);
}

.os-vow h2 em {
  color: var(--os-purple);
  font-style: normal;
}

.os-closing {
  padding-top: clamp(100px, 13vw, 180px);
  padding-bottom: clamp(120px, 14vw, 210px);
  text-align: center;
}

.os-closing-mark {
  margin-bottom: 84px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--os-white);
}

.os-emblem--small {
  width: 66px;
  margin-right: 24px;
}

.os-closing-mark > span {
  font-size: 28px;
  letter-spacing: 0.02em;
}

.os-closing-mark > i {
  width: 1px;
  height: 26px;
  margin-inline: 12px 10px;
  background: rgba(217, 220, 236, 0.3);
}

.os-closing-mark > b {
  color: var(--os-purple);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: lowercase;
}

.os-closing h2 {
  max-width: 980px;
  margin: 28px auto 0;
  font-size: clamp(50px, 6.7vw, 90px);
}

.os-closing > a {
  margin: 38px auto 0;
}

/* ---------- Motion: one boot, one rail, quiet reveals ---------- */

@media (prefers-reduced-motion: no-preference) {
  .os-emblem-orbit {
    animation: os-emblem-in 900ms var(--os-ease) 100ms backwards;
  }

  .os-emblem-ring--outer {
    animation: os-ring-in 1100ms var(--os-ease) 180ms backwards;
  }

  .os-emblem-ring--inner {
    animation: os-ring-in 900ms var(--os-ease) 260ms backwards;
  }

  .os-wordmark {
    animation: os-rise-in 620ms var(--os-ease) 350ms backwards;
  }

  .os-boot-rail {
    animation: os-rise-in 520ms var(--os-ease) 470ms backwards;
  }

  .os-boot-rail span {
    animation: os-boot-fill 1800ms linear 520ms backwards;
  }

  .os-boot-lockup {
    transition:
      opacity 420ms var(--os-ease),
      transform 760ms var(--os-ease);
  }

  .os-auto-transition .os-boot-lockup {
    opacity: 0.58;
    transform: scale(0.985);
  }

  .os-boot-complete .os-boot-state span:last-child {
    color: var(--os-cyan);
  }

  .os-boot-state {
    animation: os-rise-in 620ms var(--os-ease) 660ms backwards;
  }

  .os-motion-ready [data-os-reveal] {
    opacity: 0;
    transform: translateY(24px);
    transition:
      opacity 560ms var(--os-ease),
      transform 560ms var(--os-ease);
  }

  .os-motion-ready [data-os-reveal].is-visible {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes os-emblem-in {
  from { opacity: 0; transform: scale(0.94); }
}

@keyframes os-ring-in {
  from { opacity: 0; transform: scale(0.78); }
}

@keyframes os-rise-in {
  from { opacity: 0; transform: translateY(16px); }
}

@keyframes os-boot-fill {
  from { transform: scaleX(0); }
}

@media (hover: hover) and (pointer: fine) {
  .os-feature:hover .os-feature-art > div {
    transform: scale(1.012);
  }

  .os-feature:hover .feature-pointer--agent {
    transform: translate(-18px, 18px);
  }

  .os-feature:hover .feature-browser span:nth-child(3) {
    transform: translate(10px, 8px);
  }
}

/* ---------- Responsive ---------- */

@media (max-width: 960px) {
  .os-definition-grid {
    grid-template-columns: 1fr;
    gap: 38px;
  }

  .os-boundaries-head {
    align-items: flex-start;
    flex-direction: column;
  }

  .os-feature {
    grid-template-columns: 1fr;
  }

  .os-feature-art,
  .os-feature:nth-child(even) .os-feature-art {
    grid-column: 1;
    grid-row: auto;
    border-inline: 0;
    border-bottom: 1px solid var(--os-line);
  }

  .os-feature-copy,
  .os-feature:nth-child(even) .os-feature-copy {
    grid-column: 1;
    grid-row: auto;
  }
}

@media (max-width: 640px) {
  .os-shell {
    background-size: 40px 40px;
  }

  .os-page-progress {
    width: auto;
    height: 1px;
    inset: 70px 0 auto;
  }

  .os-page-progress span {
    transform: scaleX(var(--os-page-progress, 0));
    transform-origin: left;
  }

  .os-hero {
    min-height: 100svh;
    padding: 96px 20px 44px 24px;
  }

  .os-hero::before {
    width: 120vw;
    top: 40%;
  }

  .os-boot-lockup {
    width: min(100%, 300px);
  }

  .os-emblem-orbit {
    width: 178px;
  }

  .os-emblem {
    width: 140px;
  }

  .os-wordmark {
    margin-top: 30px;
  }

  .os-wordmark span {
    font-size: 38px;
  }

  .os-wordmark i {
    height: 32px;
    margin-inline: 13px 11px;
    top: 5px;
  }

  .os-wordmark b {
    font-size: 14px;
  }

  .os-boot-rail {
    width: 238px;
    margin-top: 34px;
  }

  .os-boot-state {
    width: 238px;
    font-size: 7px;
  }

  .os-definition,
  .os-boundaries,
  .os-vow,
  .os-closing {
    padding-inline: 24px 20px;
  }

  .os-definition {
    padding-top: 108px;
    padding-bottom: 100px;
  }

  .os-section-head {
    padding-bottom: 16px;
  }

  .os-section-head > span {
    display: none;
  }

  .os-definition-grid {
    padding-top: 42px;
  }

  .os-definition h2,
  .os-boundaries-head h2 {
    font-size: clamp(41px, 11vw, 52px);
  }

  .os-definition-list li {
    grid-template-columns: 36px 1fr;
    gap: 4px 12px;
  }

  .os-definition-list p {
    grid-column: 2;
    font-size: 13px;
  }

  .os-definition-summary {
    margin-top: 42px;
  }

  .os-system-map {
    min-height: 260px;
    margin-top: 72px;
    grid-template-columns: 1fr;
    grid-template-rows: auto 1fr auto;
    gap: 24px;
  }

  .os-map-anchor--agent {
    align-items: flex-start;
    text-align: left;
  }

  .os-map-rail {
    width: 1px;
    height: 100px;
    margin-left: 4px;
    flex-direction: column;
  }

  .os-map-rail::before {
    inset: 0 -24px;
    background:
      linear-gradient(180deg, transparent, rgba(78, 231, 238, 0.04) 50%, transparent),
      repeating-linear-gradient(180deg, transparent 0 31px, rgba(217, 220, 236, 0.045) 32px);
  }

  .os-map-rail > span {
    transform: scaleY(var(--os-map-progress, 0));
    transform-origin: top;
  }

  .os-signal-line {
    min-height: 116px;
    padding-top: 20px;
    grid-template-columns: repeat(2, 1fr);
    display: grid;
    gap: 12px 22px;
  }

  .os-signal-line i {
    display: none;
  }

  .os-boundaries {
    padding-top: 24px;
    padding-bottom: 112px;
  }

  .os-boundaries-head > p {
    font-size: 14px;
  }

  .os-feature-grid {
    margin-top: 40px;
  }

  .os-feature-meta {
    min-height: 56px;
    grid-template-columns: 52px 1fr;
  }

  .os-feature-meta em {
    display: none;
  }

  .os-feature-art {
    min-height: min(92vw, 390px);
  }

  .os-feature-copy {
    padding: 32px 0 42px;
    gap: 42px;
  }

  .os-feature-copy h3 {
    font-size: clamp(39px, 12vw, 54px);
  }

  .feature-contract {
    flex-direction: column;
    font-size: clamp(34px, 11vw, 46px);
  }

  .os-vow {
    padding-top: 106px;
    padding-bottom: 120px;
  }

  .os-vow h2 {
    margin-top: 26px;
    font-size: clamp(47px, 12.5vw, 60px);
  }

  .os-closing {
    padding-top: 98px;
    padding-bottom: 122px;
  }

  .os-closing-mark {
    margin-bottom: 68px;
  }

  .os-emblem--small {
    width: 56px;
    margin-right: 18px;
  }

  .os-closing h2 {
    font-size: clamp(44px, 12vw, 58px);
  }
}

@media (max-height: 520px) and (orientation: landscape) {
  .os-hero {
    padding: 76px 24px 18px;
  }

  .os-emblem-orbit {
    width: 146px;
  }

  .os-emblem {
    width: 116px;
  }

  .os-wordmark {
    margin-top: 14px;
  }

  .os-wordmark span {
    font-size: 32px;
  }

  .os-wordmark i {
    height: 26px;
    margin-inline: 11px 9px;
    top: 4px;
  }

  .os-wordmark b {
    font-size: 12px;
  }

  .os-boot-rail {
    width: 220px;
    margin-top: 16px;
  }

  .os-boot-state {
    width: 220px;
    margin-top: 7px;
    font-size: 7px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .os-page-progress span,
  .os-map-rail > span {
    will-change: auto;
  }

  .os-emblem-orbit,
  .os-emblem-ring,
  .os-wordmark,
  .os-boot-rail,
  .os-boot-rail span,
  .os-boot-state,
  .os-feature-art > div {
    animation: none;
    transition: none;
  }

  .os-motion-ready [data-os-reveal],
  .os-motion-ready [data-os-reveal].is-visible {
    opacity: 1;
    transform: none;
    transition: opacity 150ms ease;
  }
}