:root {
  --bg: #ffffff;
  --surface: #f7f8f9;
  --text: #16181a;
  --text-secondary: #55606a;
  --border: #e3e6e8;
  --accent: #0b6ba8;
  --max-width: 720px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #121415;
    --surface: #1a1d1f;
    --text: #eef0f1;
    --text-secondary: #a4adb3;
    --border: #2b2f32;
    --accent: #4fb0e8;
  }
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "Hiragino Sans", "Noto Sans JP", -apple-system, BlinkMacSystemFont, sans-serif;
  line-height: 1.8;
}

header {
  border-bottom: 1px solid var(--border);
}

header nav {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 20px 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-weight: 700;
  font-size: 18px;
  letter-spacing: 0.02em;
  color: var(--text);
  text-decoration: none;
}

nav ul {
  list-style: none;
  display: flex;
  gap: 20px;
  margin: 0;
  padding: 0;
}

nav a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 14px;
}

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

main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 48px 24px 80px;
}

.hero {
  text-align: center;
  padding-bottom: 8px;
}

.hero-logo {
  display: block;
  height: 340px;
  width: auto;
  margin: 0 auto 16px;
}

.hero .lead {
  margin-left: auto;
  margin-right: auto;
}

h1 {
  font-size: 28px;
  margin-bottom: 8px;
}

h2 {
  font-size: 19px;
  margin-top: 40px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border);
}

p {
  color: var(--text-secondary);
}

.lead {
  font-size: 16px;
  margin-bottom: 40px;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 16px;
}

table th,
table td {
  text-align: left;
  padding: 14px 12px;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
  font-size: 14px;
}

table th {
  width: 34%;
  color: var(--text);
  font-weight: 600;
  white-space: nowrap;
}

table td {
  color: var(--text-secondary);
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 24px;
  margin-top: 16px;
}

.card ul {
  margin: 0;
  padding-left: 20px;
  color: var(--text-secondary);
}

footer {
  border-top: 1px solid var(--border);
  padding: 24px;
  text-align: center;
  font-size: 13px;
  color: var(--text-secondary);
}

footer a {
  color: var(--text-secondary);
}

.note {
  font-size: 13px;
  color: var(--text-secondary);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 12px 16px;
  margin-top: 24px;
}