:root {
  color-scheme: light;
  --bg: #f4f7fb;
  --surface: #ffffff;
  --text: #172033;
  --muted: #5f6b7a;
  --line: #d9e1eb;
  --accent: #2563eb;
  --accent-soft: #eaf1ff;
  font-family: "Segoe UI", "Yu Gothic UI", "Meiryo", sans-serif;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  line-height: 1.75;
}
header, main, footer {
  width: min(880px, calc(100% - 32px));
  margin-inline: auto;
}
header {
  padding: 28px 0 18px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.brand {
  color: var(--text);
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: .08em;
  text-decoration: none;
}
nav { display: flex; gap: 18px; }
nav a, footer a { color: var(--accent); }
main { padding-bottom: 48px; }
.hero, .panel {
  background: var(--surface);
  border: 1px solid var(--line);
  box-shadow: 0 12px 32px rgba(23, 32, 51, .06);
}
.hero { padding: clamp(30px, 7vw, 64px); }
.eyebrow {
  margin: 0 0 10px;
  color: var(--accent);
  font-size: .82rem;
  font-weight: 700;
  letter-spacing: .12em;
}
h1 {
  margin: 0;
  font-size: clamp(2rem, 7vw, 3.8rem);
  line-height: 1.2;
}
.lead {
  max-width: 680px;
  margin: 22px 0 0;
  color: var(--muted);
  font-size: 1.08rem;
}
.actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 28px; }
.button {
  display: inline-block;
  padding: 10px 18px;
  border: 1px solid var(--accent);
  background: var(--accent);
  color: #fff;
  font-weight: 700;
  text-decoration: none;
}
.button.secondary { background: #fff; color: var(--accent); }
.grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
  margin-top: 18px;
}
.panel { padding: 26px; }
.panel h2, .panel h3 { margin-top: 0; }
ul { padding-left: 1.25rem; }
.meta { color: var(--muted); font-size: .93rem; }
.prose { background: var(--surface); border: 1px solid var(--line); padding: clamp(24px, 5vw, 48px); }
.prose h2 { margin-top: 2.2em; border-bottom: 1px solid var(--line); padding-bottom: .35em; }
.prose h2:first-of-type { margin-top: 1.5em; }
code { background: var(--accent-soft); padding: .12em .35em; overflow-wrap: anywhere; }
footer { padding: 24px 0 40px; color: var(--muted); font-size: .9rem; }
@media (max-width: 640px) {
  header { align-items: flex-start; flex-direction: column; }
  .grid { grid-template-columns: 1fr; }
  nav { gap: 14px; }
}