:root {
  --bg: #100e10;
  --bg-card: #1a171a;
  --text: #e8e6e8;
  --text-sub: #9d9aa0;
  --accent: #b3242e;
  --accent-soft: rgba(179, 36, 46, 0.35);
  --border: #2c282c;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: "Hiragino Kaku Gothic ProN", "Hiragino Sans", "Noto Sans JP",
    -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.9;
  -webkit-font-smoothing: antialiased;
}

.container {
  max-width: 760px;
  margin: 0 auto;
  padding: 0 24px 96px;
}

header.site-header {
  border-bottom: 1px solid var(--border);
  background: linear-gradient(180deg, #171317 0%, var(--bg) 100%);
}

.site-header-inner {
  max-width: 760px;
  margin: 0 auto;
  padding: 20px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
}

.brand {
  font-weight: 700;
  font-size: 1.05rem;
  letter-spacing: 0.14em;
  color: var(--text);
  text-decoration: none;
  text-shadow: 0 0 18px var(--accent-soft);
}

.brand span {
  color: var(--accent);
}

nav.site-nav a {
  color: var(--text-sub);
  text-decoration: none;
  font-size: 0.85rem;
  margin-left: 20px;
}

nav.site-nav a:hover {
  color: var(--text);
}

.hero {
  text-align: center;
  padding: 88px 24px 72px;
  background: radial-gradient(
    ellipse 70% 60% at 50% 110%,
    rgba(120, 16, 24, 0.45) 0%,
    transparent 70%
  );
}

.hero h1 {
  font-size: 2.4rem;
  letter-spacing: 0.18em;
  text-shadow: 0 0 28px var(--accent-soft);
  margin-bottom: 12px;
}

.hero p.tagline {
  color: var(--text-sub);
  font-size: 1rem;
  letter-spacing: 0.08em;
}

.card-list {
  display: grid;
  gap: 16px;
  margin-top: 48px;
}

a.card {
  display: block;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 22px 26px;
  color: var(--text);
  text-decoration: none;
  transition: border-color 0.2s ease, transform 0.2s ease;
}

a.card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
}

a.card h2 {
  font-size: 1.05rem;
  margin-bottom: 4px;
}

a.card p {
  color: var(--text-sub);
  font-size: 0.85rem;
}

main.doc {
  padding-top: 56px;
}

main.doc h1 {
  font-size: 1.7rem;
  letter-spacing: 0.08em;
  margin-bottom: 8px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border);
}

main.doc p.meta {
  color: var(--text-sub);
  font-size: 0.82rem;
  margin: 12px 0 40px;
}

main.doc h2 {
  font-size: 1.15rem;
  margin: 48px 0 14px;
  padding-left: 14px;
  border-left: 4px solid var(--accent);
}

main.doc h3 {
  font-size: 1rem;
  margin: 28px 0 10px;
}

main.doc p {
  margin-bottom: 14px;
  font-size: 0.95rem;
}

main.doc ul,
main.doc ol {
  margin: 0 0 14px 1.6em;
  font-size: 0.95rem;
}

main.doc li {
  margin-bottom: 6px;
}

main.doc a {
  color: #e07078;
}

main.doc table {
  width: 100%;
  border-collapse: collapse;
  margin: 16px 0 24px;
  font-size: 0.88rem;
}

main.doc th,
main.doc td {
  border: 1px solid var(--border);
  padding: 10px 14px;
  text-align: left;
  vertical-align: top;
}

main.doc th {
  background: var(--bg-card);
  white-space: nowrap;
}

.note {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-left: 4px solid var(--accent);
  border-radius: 8px;
  padding: 14px 18px;
  font-size: 0.88rem;
  color: var(--text-sub);
  margin: 20px 0;
}

footer.site-footer {
  border-top: 1px solid var(--border);
  margin-top: 40px;
}

.site-footer-inner {
  max-width: 760px;
  margin: 0 auto;
  padding: 28px 24px;
  color: var(--text-sub);
  font-size: 0.8rem;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
}

.site-footer-inner a {
  color: var(--text-sub);
  text-decoration: none;
  margin-right: 16px;
}

.site-footer-inner a:hover {
  color: var(--text);
}

@media (max-width: 480px) {
  .hero h1 {
    font-size: 1.7rem;
  }
}