:root {
  --color-primary: #1976D2;
  --color-text: #222222;
  --color-text-sub: #666666;
  --color-border: #E5E7EB;
  --color-bg: #FFFFFF;
  --color-bg-soft: #F7F8FA;
  --radius: 10px;
  --max-width: 720px;
}

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Noto Sans JP",
    "Yu Gothic", "Segoe UI", Roboto, sans-serif;
  font-size: 15px;
  line-height: 1.75;
  -webkit-text-size-adjust: 100%;
  -webkit-font-smoothing: antialiased;
  word-wrap: break-word;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 24px 20px 48px;
}

.page-header {
  padding: 8px 0 24px;
  border-bottom: 1px solid var(--color-border);
  margin-bottom: 24px;
}

.page-header h1 {
  font-size: 22px;
  font-weight: 700;
  margin: 0 0 4px;
  color: var(--color-text);
}

.page-header .subtitle {
  margin: 0;
  color: var(--color-text-sub);
  font-size: 13px;
}

.effective-date {
  color: var(--color-text-sub);
  font-size: 13px;
  margin: 0 0 24px;
}

h2 {
  font-size: 17px;
  font-weight: 700;
  margin: 32px 0 12px;
  padding-bottom: 6px;
  border-bottom: 2px solid var(--color-primary);
  color: var(--color-text);
}

h3 {
  font-size: 15px;
  font-weight: 700;
  margin: 20px 0 8px;
  color: var(--color-text);
}

p {
  margin: 0 0 12px;
}

ul, ol {
  padding-left: 22px;
  margin: 0 0 12px;
}

li {
  margin-bottom: 4px;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin: 12px 0 20px;
  font-size: 14px;
}

th, td {
  border: 1px solid var(--color-border);
  padding: 10px 12px;
  text-align: left;
  vertical-align: top;
}

th {
  background: var(--color-bg-soft);
  font-weight: 700;
}

.note {
  background: var(--color-bg-soft);
  border-left: 3px solid var(--color-primary);
  padding: 12px 14px;
  margin: 16px 0;
  font-size: 14px;
  color: var(--color-text-sub);
  border-radius: 0 var(--radius) var(--radius) 0;
}

.contact {
  background: var(--color-bg-soft);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 16px;
  margin: 20px 0 0;
  font-size: 14px;
}

.contact p {
  margin: 4px 0;
}

.index-nav {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.index-card {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: var(--color-bg-soft);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 16px 18px;
  text-decoration: none;
  color: var(--color-text);
  font-weight: 600;
  transition: background 0.15s ease;
}

.index-card:active {
  background: #eef2f7;
}

.index-card__arrow {
  color: var(--color-text-sub);
  font-size: 22px;
  line-height: 1;
}

a {
  color: var(--color-primary);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-text: #ECEDEE;
    --color-text-sub: #9BA1A6;
    --color-border: #2A2D31;
    --color-bg: #121316;
    --color-bg-soft: #1B1D20;
  }
  th { background: #1B1D20; }
}