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

:root {
  --bg: #ffffff;
  --surface: #f5f5f7;
  --accent: #4361ee;
  --text: #111111;
  --text-muted: #666666;
  --border: #e5e5e5;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Hiragino Sans', 'Hiragino Kaku Gothic ProN', Meiryo, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  padding: 40px 20px 80px;
}

.container { max-width: 720px; margin: 0 auto; }

header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 32px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
}

.logo {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  overflow: hidden;
  flex-shrink: 0;
}

.logo img { width: 100%; height: 100%; display: block; object-fit: cover; }

.header-text { flex: 1; min-width: 140px; }

header h1 {
  font-size: 1.1rem;
  font-weight: 700;
  line-height: 1.2;
}

.header-sub {
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-top: 2px;
}

.lang-switch {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-left: auto;
}

.lang-btn {
  background: none;
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text-muted);
  font-size: 0.72rem;
  padding: 6px 10px;
  cursor: pointer;
  transition: border-color 0.15s, color 0.15s, background 0.15s;
  white-space: nowrap;
}

.lang-btn:hover { border-color: var(--accent); color: var(--accent); }

.lang-btn.active {
  border-color: var(--accent);
  color: var(--accent);
  background: rgba(67, 97, 238, 0.1);
}

.lang-section { display: none; }
.lang-section.visible { display: block; }

h2 {
  font-size: 1.05rem;
  font-weight: 700;
  margin: 36px 0 12px;
  color: var(--text);
}

h2:first-of-type { margin-top: 0; }

p { margin-bottom: 10px; font-size: 0.9rem; color: var(--text); }

.effective {
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-bottom: 28px;
}

ul { padding-left: 1.4em; margin-bottom: 12px; }
ul li { margin-bottom: 6px; font-size: 0.9rem; }

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.82rem;
  margin: 12px 0 20px;
}

th {
  text-align: left;
  padding: 8px 12px;
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text-muted);
  font-weight: 600;
}

td {
  padding: 8px 12px;
  border: 1px solid var(--border);
  vertical-align: top;
}

tr:nth-child(even) td { background: var(--surface); }

.note-box {
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  border-radius: 0 8px 8px 0;
  padding: 12px 16px;
  font-size: 0.83rem;
  margin: 12px 0 20px;
}

footer {
  margin-top: 60px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
  font-size: 0.78rem;
  color: var(--text-muted);
}

footer p { font-size: 0.78rem; color: var(--text-muted); margin-bottom: 8px; }

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

code {
  font-size: 0.85em;
  background: var(--surface);
  padding: 1px 5px;
  border-radius: 4px;
}

@media (max-width: 640px) {
  body { padding: 24px 16px 64px; }
  .lang-switch { width: 100%; margin-left: 0; margin-top: 8px; }
  .lang-btn { flex: 1 1 calc(50% - 6px); text-align: center; }
  table { font-size: 0.75rem; }
  th, td { padding: 6px 8px; }
}