:root {
  --color-bg: #f4f6f8;
  --color-surface: #ffffff;
  --color-text: #1a2332;
  --color-muted: #5c6b7a;
  --color-accent: #0d6e7a;
  --color-accent-hover: #0a5862;
  --color-border: #dde3ea;
  --color-success: #1e7a4c;
  --color-error: #b42318;
  --radius: 10px;
  --shadow: 0 2px 12px rgba(26, 35, 50, 0.08);
  --font: "Segoe UI", system-ui, -apple-system, sans-serif;
}

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

body {
  margin: 0;
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.5;
  color: var(--color-text);
  background: var(--color-bg);
}

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

.page-header {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  padding: 1rem 1.5rem;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow);
}

.page-header__inner {
  max-width: 1100px;
  margin: 0 auto;
}

.page-header__title {
  margin: 0 0 0.25rem;
  font-size: 1.5rem;
  font-weight: 600;
}

.page-header__subtitle {
  margin: 0;
  color: var(--color-muted);
  font-size: 0.9rem;
}

.page-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 1rem;
}

.page-nav__link {
  font-size: 0.85rem;
  text-decoration: none;
  padding: 0.35rem 0.65rem;
  border-radius: 6px;
  background: var(--color-bg);
  color: var(--color-text);
}

.page-nav__link:hover {
  background: var(--color-border);
}

.page-main {
  max-width: 1100px;
  margin: 0 auto;
  padding: 1.5rem;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.25rem;
  align-items: stretch;
}

.page-main > .disclaimer,
.page-main > .section-collapsible {
  grid-column: 1 / -1;
}

@media (max-width: 720px) {
  .page-main {
    grid-template-columns: 1fr;
  }
}

.page-footer {
  max-width: 1100px;
  margin: 2rem auto;
  padding: 1rem 1.5rem 2rem;
  color: var(--color-muted);
  font-size: 0.85rem;
}

.disclaimer {
  background: #fff8e6;
  border: 1px solid #f0d78c;
  border-radius: var(--radius);
  padding: 0.75rem 1rem;
  margin-bottom: 1.5rem;
  font-size: 0.9rem;
}