:root {
  color-scheme: light;
  --bg: #f7f8fa;
  --text: #17181c;
  --muted: #5d6470;
  --line: #d8dce3;
  --panel: #ffffff;
  --accent: #2f7df6;
  --accent-soft: #e9f1ff;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Yu Gothic", Meiryo, sans-serif;
  line-height: 1.75;
}

a {
  color: var(--accent);
}

.page {
  width: min(920px, calc(100% - 32px));
  margin: 0 auto;
  padding: 32px 0 56px;
}

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 12px 0 32px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
  text-decoration: none;
  color: inherit;
}

.brand img {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  box-shadow: 0 10px 24px rgba(23, 24, 28, 0.12);
}

.brand-name {
  font-size: 24px;
  font-weight: 750;
  line-height: 1.1;
}

.nav {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.nav a {
  color: var(--muted);
  text-decoration: none;
  font-weight: 650;
}

.hero {
  padding: 48px 0 36px;
}

.hero h1,
.content h1 {
  font-size: clamp(34px, 6vw, 56px);
  line-height: 1.08;
  margin: 0 0 18px;
  letter-spacing: 0;
}

.lead {
  color: var(--muted);
  font-size: 18px;
  max-width: 720px;
  margin: 0;
}

.content {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 28px;
  box-shadow: 0 16px 40px rgba(23, 24, 28, 0.06);
}

.content h2 {
  font-size: 24px;
  margin: 32px 0 8px;
}

.content h2:first-child {
  margin-top: 0;
}

.content h3 {
  font-size: 18px;
  margin: 24px 0 8px;
}

.content p,
.content ul {
  margin: 0 0 16px;
}

.content ul {
  padding-left: 1.4em;
}

.actions {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
  margin-top: 32px;
}

.action {
  display: block;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 20px;
  text-decoration: none;
  color: inherit;
}

.action strong {
  display: block;
  font-size: 18px;
  margin-bottom: 4px;
}

.action span {
  color: var(--muted);
}

.note {
  background: var(--accent-soft);
  border: 1px solid #c8dcff;
  border-radius: 8px;
  padding: 16px;
}

.site-footer {
  color: var(--muted);
  font-size: 14px;
  margin-top: 32px;
}

@media (max-width: 640px) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
  }

  .nav {
    justify-content: flex-start;
  }

  .content {
    padding: 22px;
  }

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