:root {
  color-scheme: dark;
  --bg: #09111f;
  --panel: #111d31;
  --panel-strong: #162741;
  --line: #2d4263;
  --text: #f3f7ff;
  --muted: #b6c4d9;
  --cyan: #6de7f5;
  --pink: #ff88c9;
  --yellow: #ffe08a;
  --danger: #ffb0a8;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans JP",
    sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background:
    radial-gradient(circle at 10% 0%, rgba(109, 231, 245, 0.13), transparent 32rem),
    radial-gradient(circle at 90% 15%, rgba(255, 136, 201, 0.12), transparent 28rem),
    var(--bg);
  color: var(--text);
  line-height: 1.8;
}

a {
  color: var(--cyan);
  text-underline-offset: 0.18em;
}

a:hover,
a:focus-visible {
  color: white;
}

.shell {
  width: min(1080px, calc(100% - 2rem));
  margin: 0 auto;
}

.site-header {
  border-bottom: 1px solid rgba(109, 231, 245, 0.22);
  background: rgba(9, 17, 31, 0.9);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1rem 0;
}

.brand {
  color: var(--text);
  font-weight: 800;
  letter-spacing: 0.03em;
  text-decoration: none;
}

.brand small {
  display: block;
  color: var(--muted);
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.08em;
}

nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 0.7rem 1rem;
}

nav a {
  font-size: 0.92rem;
}

main {
  padding: 3.5rem 0 5rem;
}

.hero {
  display: grid;
  grid-template-columns: 1.5fr 1fr;
  gap: 2rem;
  align-items: stretch;
  margin-bottom: 2rem;
}

.hero h1 {
  margin: 0 0 0.75rem;
  font-size: clamp(2.3rem, 7vw, 4.5rem);
  line-height: 1.12;
  letter-spacing: -0.04em;
}

.hero h1 span {
  color: var(--pink);
}

.lede {
  max-width: 44rem;
  color: var(--muted);
  font-size: clamp(1.08rem, 2vw, 1.3rem);
}

.eyebrow {
  margin: 0 0 0.65rem;
  color: var(--cyan);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.notice,
.card {
  border: 1px solid var(--line);
  border-radius: 1.25rem;
  background: rgba(17, 29, 49, 0.88);
  padding: 1.4rem;
}

.notice {
  border-color: rgba(255, 224, 138, 0.55);
  background: rgba(74, 60, 27, 0.34);
}

.notice strong {
  color: var(--yellow);
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
  margin: 1rem 0 2rem;
}

.card h2,
.card h3,
section h2 {
  margin-top: 0;
  line-height: 1.35;
}

.card h2,
section h2 {
  color: var(--cyan);
}

.card h3 {
  color: var(--pink);
}

.card p:last-child,
.card ul:last-child,
section p:last-child,
section ul:last-child {
  margin-bottom: 0;
}

section {
  margin: 2.5rem 0;
}

section > h2 {
  padding-bottom: 0.45rem;
  border-bottom: 1px solid var(--line);
}

ul,
ol {
  padding-left: 1.4rem;
}

li + li {
  margin-top: 0.45rem;
}

.pill {
  display: inline-block;
  margin: 0.15rem 0.35rem 0.15rem 0;
  padding: 0.2rem 0.65rem;
  border: 1px solid rgba(109, 231, 245, 0.45);
  border-radius: 999px;
  color: var(--cyan);
  font-size: 0.86rem;
}

.meta {
  color: var(--muted);
  font-size: 0.9rem;
}

.placeholder {
  color: var(--yellow);
  font-family: ui-monospace, SFMono-Regular, Consolas, monospace;
  overflow-wrap: anywhere;
}

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

table {
  width: 100%;
  border-collapse: collapse;
  min-width: 38rem;
}

th,
td {
  padding: 0.8rem;
  border: 1px solid var(--line);
  vertical-align: top;
  text-align: left;
}

th {
  color: var(--cyan);
  background: rgba(22, 39, 65, 0.75);
}

code {
  padding: 0.12rem 0.3rem;
  border-radius: 0.3rem;
  background: rgba(0, 0, 0, 0.25);
  color: var(--yellow);
}

.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
  margin-top: 1.4rem;
}

.button {
  display: inline-block;
  padding: 0.65rem 1rem;
  border-radius: 0.7rem;
  background: var(--cyan);
  color: #07121f;
  font-weight: 800;
  text-decoration: none;
}

.button.secondary {
  border: 1px solid var(--line);
  background: transparent;
  color: var(--text);
}

.site-footer {
  border-top: 1px solid rgba(109, 231, 245, 0.22);
  padding: 1.5rem 0 3rem;
  color: var(--muted);
  font-size: 0.86rem;
}

.site-footer nav {
  justify-content: flex-start;
  margin-bottom: 0.8rem;
}

.small {
  font-size: 0.9rem;
}

@media (max-width: 760px) {
  .header-inner,
  .hero {
    display: block;
  }

  nav {
    justify-content: flex-start;
    margin-top: 0.9rem;
  }

  main {
    padding-top: 2.2rem;
  }

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

  .notice,
  .card {
    padding: 1.1rem;
  }
}

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