:root {
  color-scheme: light;
  --bg: #f8fbfd;
  --surface: #ffffff;
  --surface-soft: #f1f8f5;
  --surface-strong: #e8f5f0;
  --ink: #1d2520;
  --muted: #5f6c66;
  --line: #d8e5df;
  --line-strong: #b8cec5;
  --accent: #0a8f72;
  --accent-strong: #06745f;
  --accent-soft: #dff4ed;
  --blue-green: #0d7f8f;
  --warning: #b7791f;
  --shadow: 0 18px 45px rgba(34, 70, 55, 0.12);
  --max-width: 1320px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: "Segoe UI", "Apple SD Gothic Neo", "Malgun Gothic", system-ui, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  letter-spacing: 0;
  word-break: keep-all;
}

body.nav-open {
  overflow: hidden;
}

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

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

p,
h1,
h2,
h3 {
  margin: 0;
  overflow-wrap: break-word;
}

ul {
  margin: 0;
  padding: 0;
}

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

.skip-link {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 100;
  transform: translateY(-160%);
  border-radius: 6px;
  background: var(--accent-strong);
  color: #fff;
  padding: 10px 14px;
  transition: transform 160ms ease;
}

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

.container {
  width: min(100% - 48px, var(--max-width));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 72px;
  padding: 12px 28px;
  border-bottom: 1px solid rgba(216, 229, 223, 0.9);
  background: rgba(248, 251, 253, 0.94);
  backdrop-filter: blur(16px);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
}

.brand-logo {
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
}

.brand-logo img {
  width: 34px;
  height: 34px;
  object-fit: contain;
}

.brand strong,
.brand small {
  display: block;
  white-space: nowrap;
}

.brand strong {
  font-size: 0.98rem;
  line-height: 1.2;
}

.brand small {
  color: var(--muted);
  font-size: 0.78rem;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 4px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
}

.site-nav a {
  border-radius: 6px;
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 700;
  padding: 8px 12px;
  transition: background 160ms ease, color 160ms ease;
}

.site-nav a:hover,
.site-nav a.active {
  background: var(--accent-soft);
  color: var(--accent-strong);
}

.language-switcher {
  display: inline-flex;
  flex: 0 0 auto;
  align-items: center;
  gap: 3px;
  min-height: 42px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  color: var(--line-strong);
  padding: 4px;
}

.language-switcher button {
  border: 0;
  border-radius: 6px;
  background: transparent;
  color: var(--muted);
  cursor: pointer;
  font-size: 0.78rem;
  font-weight: 800;
  line-height: 1;
  padding: 9px 8px;
  transition: background 160ms ease, color 160ms ease;
}

.language-switcher button:hover,
.language-switcher button[aria-pressed="true"] {
  background: var(--accent-soft);
  color: var(--accent-strong);
}

.language-switcher button:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.hero {
  padding: 80px 0 72px;
  border-bottom: 1px solid var(--line);
  background:
    linear-gradient(180deg, #ffffff 0%, #f5fbf8 100%);
}

.hero-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 420px;
  gap: 48px;
  align-items: center;
}

.hero-copy {
  max-width: 720px;
}

.eyebrow {
  margin-bottom: 12px;
  color: var(--accent-strong);
  font-size: 0.78rem;
  font-weight: 800;
  text-transform: uppercase;
}

h1 {
  max-width: 760px;
  font-size: 3.25rem;
  line-height: 1.1;
  font-weight: 800;
}

.lead {
  max-width: 700px;
  margin-top: 22px;
  color: #34413b;
  font-size: 1.12rem;
}

.hero-facts {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  max-width: 700px;
  margin-top: 24px;
}

.hero-facts span {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 34px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--surface);
  color: #30413a;
  font-size: 0.86rem;
  font-weight: 800;
  padding: 6px 11px;
}

.hero-panel {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.device-photo {
  margin: 0;
  border-bottom: 1px solid var(--line);
  overflow: hidden;
}

.device-photo img {
  width: 100%;
  height: clamp(260px, 24vw, 330px);
  object-fit: contain;
  background: #fff;
  padding: 14px;
}

figcaption {
  color: var(--muted);
  font-size: 0.88rem;
  padding: 12px 14px 0;
}

.section {
  padding: 78px 0;
}

.section-muted {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: var(--surface-soft);
}

.section-heading {
  max-width: 780px;
  margin-bottom: 30px;
}

.section-heading.split {
  display: grid;
  grid-template-columns: minmax(0, 0.8fr) minmax(280px, 1fr);
  gap: 36px;
  max-width: none;
  align-items: end;
}

.section-heading h2 {
  font-size: 2.15rem;
  line-height: 1.18;
  font-weight: 800;
}

.section-heading p:not(.eyebrow) {
  color: var(--muted);
}

.overview-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
}

.airframe-feature {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(280px, 0.85fr);
  gap: 18px;
  margin-bottom: 18px;
  align-items: stretch;
}

.airframe-feature .media-card,
.airframe-feature .detail-card {
  height: 100%;
}

.airframe-media img {
  height: clamp(260px, 30vw, 360px);
}

.airframe-detail {
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.info-card,
.detail-card,
.flow-step,
.task-board article,
.packet-list article {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
}

.info-card {
  min-height: 210px;
  padding: 22px;
}

.info-card h3,
.detail-card h3,
.flow-step h3,
.task-board h3,
.packet-list h3 {
  margin-bottom: 10px;
  font-size: 1.08rem;
  line-height: 1.3;
}

.info-card p,
.detail-card p,
.flow-step p,
.task-board p,
.packet-list p {
  color: var(--muted);
  font-size: 0.95rem;
}

.card-index {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 28px;
  margin-bottom: 22px;
  border-radius: 6px;
  background: var(--accent-soft);
  color: var(--accent-strong);
  font-size: 0.78rem;
  font-weight: 900;
}

.status-strip {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0;
  margin-top: 18px;
  border: 1px solid var(--line);
  border-radius: 8px;
  overflow: hidden;
  background: var(--surface);
}

.status-strip div {
  padding: 18px 20px;
}

.status-strip div + div {
  border-left: 1px solid var(--line);
}

.status-strip strong,
.status-strip span {
  display: block;
}

.status-strip strong {
  margin-bottom: 6px;
}

.status-strip span {
  color: var(--muted);
  font-size: 0.94rem;
}

.system-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(260px, 0.7fr);
  gap: 18px;
  align-items: start;
}

.table-card {
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
}

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

caption {
  height: 1px;
  overflow: hidden;
  position: absolute;
  white-space: nowrap;
  width: 1px;
}

th,
td {
  border-bottom: 1px solid var(--line);
  padding: 14px 16px;
  text-align: left;
  vertical-align: top;
}

th {
  background: #f7fbf9;
  color: #2d3b35;
  font-size: 0.86rem;
}

td {
  color: var(--muted);
  font-size: 0.92rem;
}

td:first-child,
td:nth-child(2) {
  color: var(--ink);
  font-weight: 800;
}

tr:last-child td {
  border-bottom: 0;
}

.module-stack {
  display: grid;
  gap: 12px;
}

.module-stack article {
  border-left: 4px solid var(--accent);
  border-radius: 8px;
  background: #fff;
  padding: 18px;
}

.module-stack h3 {
  margin-bottom: 8px;
  font-size: 1rem;
}

.module-stack p {
  color: var(--muted);
  font-size: 0.92rem;
}

.flow-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
}

.navigation-layout {
  display: grid;
  grid-template-columns: minmax(0, 0.86fr) minmax(420px, 1.14fr);
  gap: 18px;
  align-items: stretch;
}

.navigation-layout .flow-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.flow-step {
  padding: 22px;
}

.flow-step span {
  display: inline-flex;
  margin-bottom: 18px;
  border-radius: 999px;
  background: var(--surface-strong);
  color: var(--accent-strong);
  font-size: 0.76rem;
  font-weight: 900;
  padding: 5px 10px;
}

.media-pair,
.control-layout,
.gcs-layout {
  display: grid;
  grid-template-columns: minmax(0, 0.95fr) minmax(320px, 1.05fr);
  gap: 18px;
  margin-top: 18px;
  align-items: start;
}

.media-card {
  margin: 0;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
}

.media-card img {
  width: 100%;
  height: clamp(300px, 34vw, 430px);
  object-fit: contain;
  background: #fff;
  padding: 14px;
}

.media-card.wide img {
  height: clamp(300px, 34vw, 430px);
  object-fit: contain;
}

.navigation-flowchart img {
  height: clamp(340px, 32vw, 500px);
}

.detail-card {
  padding: 24px;
}

.plain-list {
  display: grid;
  gap: 10px;
  margin-top: 16px;
  list-style: none;
}

.plain-list li {
  position: relative;
  color: var(--muted);
  padding-left: 18px;
}

.plain-list li::before {
  position: absolute;
  top: 0.72em;
  left: 0;
  width: 6px;
  height: 6px;
  border-radius: 999px;
  background: var(--accent);
  content: "";
}

.control-layout {
  grid-template-columns: minmax(0, 0.85fr) minmax(320px, 1.15fr);
}

.control-cards {
  display: grid;
  gap: 14px;
}

.control-cards .info-card {
  min-height: auto;
}

.video-grid {
  display: grid;
  grid-template-columns: minmax(0, 2.4fr) minmax(220px, 0.9fr);
  gap: 1.25rem;
  margin-top: 18px;
  align-items: start;
}

.verification-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 22px;
  margin-top: 18px;
  align-items: start;
}

.video-card {
  margin: 0;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  align-self: start;
}

.video-card video {
  display: block;
  width: 100%;
  background: #000;
}

.video-card iframe {
  display: block;
  width: 100%;
  border: 0;
  aspect-ratio: 16 / 9;
  background: #000;
}

.video-card:not(.portrait) video {
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: contain;
}

.video-card.portrait {
  max-width: 260px;
}

.video-card.portrait video {
  aspect-ratio: 9 / 16;
  max-height: 340px;
  object-fit: contain;
}

.video-card figcaption {
  padding: 0.75rem 0.9rem;
  color: #425466;
  font-size: 0.9rem;
}

.task-board {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.task-board article {
  padding: 20px;
}

.task-priority {
  display: inline-flex;
  margin-bottom: 14px;
  border-radius: 999px;
  font-size: 0.72rem;
  font-weight: 900;
  padding: 5px 9px;
}

.task-priority.high {
  background: #dff4ed;
  color: #06745f;
}

.task-priority.medium {
  background: #e2f3f5;
  color: #0d7080;
}

.task-priority.normal {
  background: #eef6e7;
  color: #55751e;
}

.task-priority.low {
  background: #fff3d8;
  color: var(--warning);
}

.gcs-layout {
  grid-template-columns: minmax(0, 1.15fr) minmax(300px, 0.85fr);
}

.packet-list {
  display: grid;
  gap: 12px;
}

.packet-list article {
  padding: 20px;
}

.verification-notes {
  margin-top: 18px;
  border-top: 1px solid var(--line);
  padding-top: 18px;
}

.verification-notes h3 {
  margin-bottom: 12px;
  font-size: 1.05rem;
}

.verification-notes ul {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 12px;
  list-style: none;
}

.verification-notes li {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  color: var(--muted);
  font-size: 0.94rem;
  padding: 14px 16px;
}

.site-footer {
  border-top: 1px solid var(--line);
  background: #fff;
  padding: 28px 0;
}

.footer-layout {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}

.site-footer strong {
  display: block;
  margin-bottom: 2px;
}

.site-footer p {
  color: var(--muted);
  font-size: 0.92rem;
}

.site-footer a {
  color: var(--accent-strong);
  font-weight: 800;
}

.reveal {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 360ms ease, transform 360ms ease;
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }
}

@media (max-width: 1060px) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
    gap: 12px;
  }

  .header-actions {
    width: 100%;
  }

  .site-nav {
    flex: 1 1 auto;
    width: auto;
    overflow-x: auto;
    justify-content: flex-start;
  }

  .hero-layout,
  .system-layout,
  .navigation-layout,
  .media-pair,
  .control-layout,
  .gcs-layout {
    grid-template-columns: 1fr;
  }

  .hero-panel {
    max-width: 640px;
  }

  .overview-grid,
  .airframe-feature,
  .flow-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .task-board {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .verification-notes ul {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 760px) {
  .container {
    width: min(100% - 28px, var(--max-width));
  }

  .site-header {
    min-height: auto;
    padding: 10px 14px;
  }

  .brand strong {
    white-space: normal;
  }

  .site-nav a {
    flex: 0 0 auto;
    padding: 8px 10px;
  }

  .header-actions {
    gap: 8px;
  }

  .language-switcher button {
    padding-inline: 7px;
  }

  .hero {
    padding: 48px 0;
  }

  h1 {
    font-size: 2.25rem;
  }

  .lead {
    font-size: 1rem;
  }

  .section {
    padding: 54px 0;
  }

  .section-heading,
  .section-heading.split {
    display: block;
    margin-bottom: 22px;
  }

  .section-heading h2 {
    font-size: 1.78rem;
  }

  .section-heading.split p:not(.eyebrow) {
    margin-top: 12px;
  }

  .overview-grid,
  .airframe-feature,
  .flow-grid,
  .task-board,
  .verification-grid,
  .status-strip {
    grid-template-columns: 1fr;
  }

  .video-grid {
    grid-template-columns: 1fr;
  }

  .navigation-layout .flow-grid {
    grid-template-columns: 1fr;
  }

  .video-card.portrait {
    max-width: 320px;
  }

  .verification-notes ul {
    grid-template-columns: 1fr;
  }

  .status-strip div + div {
    border-top: 1px solid var(--line);
    border-left: 0;
  }

  .info-card {
    min-height: auto;
  }

  .table-card {
    overflow-x: auto;
  }

  table {
    min-width: 660px;
  }

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