:root {
  color-scheme: light dark;
  --navy: #07316d;
  --navy-deep: #031b3d;
  --blue: #1976d2;
  --ink: #172033;
  --muted: #5e6879;
  --surface: #ffffff;
  --soft: #f1f5fa;
  --line: #dce3ec;
  --max-width: 1040px;
}

* {
  box-sizing: border-box;
}

html {
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Yu Gothic", sans-serif;
  color: var(--ink);
  background: var(--surface);
  line-height: 1.75;
}

body {
  margin: 0;
}

a {
  color: inherit;
}

.site-header {
  min-height: 72px;
  padding: 12px max(20px, calc((100% - var(--max-width)) / 2));
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  border-bottom: 1px solid var(--line);
  background: color-mix(in srgb, var(--surface) 94%, transparent);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--ink);
  font-size: 1.05rem;
  font-weight: 700;
  text-decoration: none;
}

.brand img {
  border-radius: 10px;
}

nav {
  display: flex;
  gap: 24px;
}

nav a,
footer a {
  color: var(--muted);
  font-size: 0.92rem;
  text-decoration: none;
}

nav a:hover,
nav a[aria-current="page"],
footer a:hover {
  color: var(--blue);
}

.hero {
  background: var(--navy-deep);
  color: #ffffff;
}

.hero-inner {
  width: min(var(--max-width), calc(100% - 40px));
  min-height: 520px;
  margin: 0 auto;
  padding: 72px 0;
  display: grid;
  grid-template-columns: 280px minmax(0, 1fr);
  align-items: center;
  gap: 72px;
}

.app-icon {
  width: 100%;
  max-width: 240px;
  height: auto;
  border-radius: 22%;
  box-shadow: 0 24px 64px rgb(0 0 0 / 30%);
}

.hero h1 {
  margin: 0;
  font-size: clamp(3rem, 8vw, 5.5rem);
  line-height: 1;
}

.hero-copy {
  max-width: 620px;
}

.hero-copy p {
  color: #d8e4f6;
  font-size: 1.08rem;
}

.hero-copy .lead {
  margin: 24px 0 12px;
  color: #ffffff;
  font-size: clamp(1.35rem, 3vw, 2rem);
  font-weight: 700;
}

.content-section {
  padding: 80px 20px;
}

.section-inner {
  width: min(var(--max-width), 100%);
  margin: 0 auto;
}

.section-inner.narrow {
  max-width: 720px;
}

h2 {
  margin: 0 0 24px;
  font-size: 1.75rem;
  line-height: 1.4;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 40px;
}

.feature-grid article {
  border-top: 3px solid var(--blue);
  padding-top: 20px;
}

.feature-grid h3 {
  margin: 0 0 8px;
  font-size: 1.2rem;
}

.feature-grid p,
.muted-section p {
  color: var(--muted);
}

.muted-section {
  background: var(--soft);
}

.text-link,
.document a {
  color: var(--blue);
  font-weight: 600;
}

.document {
  padding: 72px 20px 96px;
}

.document-inner {
  width: min(760px, 100%);
  margin: 0 auto;
}

.document h1 {
  margin: 0 0 8px;
  font-size: clamp(2.2rem, 6vw, 3.5rem);
  line-height: 1.25;
}

.document h2 {
  margin: 48px 0 12px;
  padding-top: 24px;
  border-top: 1px solid var(--line);
  font-size: 1.25rem;
}

.eyebrow {
  margin: 0 0 8px;
  color: var(--blue);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.08em;
}

.updated,
.note {
  color: var(--muted);
  font-size: 0.9rem;
}

pre {
  overflow-x: auto;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--soft);
}

.contact-link {
  display: inline-block;
  font-size: 1.1rem;
}

footer {
  width: min(var(--max-width), calc(100% - 40px));
  min-height: 96px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.9rem;
}

footer div {
  display: flex;
  gap: 20px;
}

@media (max-width: 700px) {
  .site-header {
    align-items: flex-start;
  }

  .brand span {
    display: none;
  }

  nav {
    gap: 16px;
  }

  .hero-inner {
    min-height: auto;
    padding: 48px 0 64px;
    grid-template-columns: 1fr;
    gap: 36px;
  }

  .app-icon {
    max-width: 152px;
  }

  .feature-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .content-section,
  .document {
    padding-top: 56px;
    padding-bottom: 64px;
  }

  footer {
    padding: 24px 0;
    align-items: flex-start;
    flex-direction: column;
  }
}

@media (prefers-color-scheme: dark) {
  :root {
    --ink: #f4f7fb;
    --muted: #b4becc;
    --surface: #11141a;
    --soft: #191e27;
    --line: #303746;
    --blue: #64a8f5;
  }
}