/* yohei.tokyo — 軽量・依存なし（外部フォント/解析なし） */
:root {
  --bg: #faf9f6;
  --fg: #22252a;
  --muted: #6b7280;
  --accent: #3d5a80;
  --accent-ink: #f8f6f1;
  --card-bg: #ffffff;
  --border: #e5e2da;
  --code-bg: #f1efe9;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #17191e;
    --fg: #e8e6e1;
    --muted: #9aa1ab;
    --accent: #8fb2dd;
    --accent-ink: #17191e;
    --card-bg: #1f2229;
    --border: #2e323b;
    --code-bg: #262a33;
  }
}

* {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Kaku Gothic ProN",
    "Hiragino Sans", "Noto Sans JP", "Yu Gothic UI", Meiryo, sans-serif;
  font-size: 16px;
  line-height: 1.8;
  letter-spacing: 0.01em;
}

.container {
  max-width: 44rem;
  margin: 0 auto;
  padding: 0 1.25rem;
}

a {
  color: var(--accent);
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

a:hover {
  text-decoration-thickness: 2px;
}

/* --- header / footer --- */
.site-header {
  border-bottom: 1px solid var(--border);
  background: var(--card-bg);
}

.site-header .container {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
  padding-top: 1rem;
  padding-bottom: 1rem;
}

.site-name {
  font-weight: 700;
  font-size: 1.05rem;
  text-decoration: none;
  color: var(--fg);
  letter-spacing: 0.03em;
}

.site-nav {
  display: flex;
  gap: 1.1rem;
  font-size: 0.9rem;
}

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

.site-nav a:hover,
.site-nav a[aria-current="page"] {
  color: var(--accent);
  text-decoration: underline;
}

.site-footer {
  margin-top: 3rem;
  border-top: 1px solid var(--border);
  padding: 1.5rem 0 2.5rem;
  color: var(--muted);
  font-size: 0.9rem;
}

.footer-nav {
  display: flex;
  gap: 1.1rem;
  flex-wrap: wrap;
  margin-bottom: 0.5rem;
}

.footer-nav a {
  color: var(--muted);
}

/* --- main --- */
main {
  padding-top: 2.5rem;
}

.hero h1 {
  font-size: clamp(1.5rem, 4vw, 2rem);
  line-height: 1.4;
  margin: 0 0 0.75rem;
  letter-spacing: 0.04em;
}

.lead {
  color: var(--muted);
  margin: 0 0 2rem;
  max-width: 38rem;
}

.card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.25rem 1.4rem;
  margin-bottom: 1.25rem;
}

.card h2 {
  font-size: 1.05rem;
  letter-spacing: 0.04em;
  margin: 0 0 0.5rem;
}

.card p {
  margin: 0.5rem 0;
}

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

.plain-list {
  padding-left: 1.2rem;
  margin: 0.5rem 0;
}

.plain-list li {
  margin: 0.4rem 0;
}

/* --- legal pages --- */
.legal h1 {
  font-size: clamp(1.4rem, 3.5vw, 1.75rem);
  letter-spacing: 0.04em;
  margin: 0 0 0.25rem;
}

.legal-meta {
  color: var(--muted);
  font-size: 0.85rem;
  margin: 0 0 1.75rem;
}

.legal h2 {
  font-size: 1.05rem;
  letter-spacing: 0.04em;
  margin: 2.25rem 0 0.5rem;
  padding-left: 0.7rem;
  border-left: 3px solid var(--accent);
}

.legal h3 {
  font-size: 0.95rem;
  margin: 1.5rem 0 0.25rem;
}

.legal p,
.legal ul {
  font-size: 0.95rem;
}

.legal ul {
  padding-left: 1.3rem;
  margin: 0.5rem 0;
}

.legal li {
  margin: 0.35rem 0;
}

code {
  background: var(--code-bg);
  border-radius: 4px;
  padding: 0.1em 0.35em;
  font-size: 0.9em;
}