body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Arial, sans-serif;
  font-size: 18px;
  line-height: 1.6;
  color: #222;
  margin: 0;
  background-color: #ffffff;
}

h1, h2, h3 {
  font-weight: 500;
  line-height: 1.25;
  margin-bottom: 0.75em;
}

h1 {
  font-size: 2rem;
  margin-top: 0;
}

h2 {
  font-size: 1.4rem;
  margin-top: 2em;
}

h3 {
  font-size: 1.05rem;
  margin-top: 1.5em;
  font-weight: 500;
}

p {
  margin-bottom: 1.2em;
}

ul {
  margin-bottom: 1.2em;
  padding-left: 1.4em;
}

a {
  color: #111;
  text-decoration: underline;
  text-underline-offset: 3px;
}

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

.site-nav {
  border-bottom: 1px solid #e5e5e5;
  padding: 18px 0;
}

.nav-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.brand a {
  text-decoration: none;
  color: #111;
  font-weight: 400;
  font-size: 1rem;
}

.nav-links a {
  margin-left: 40px;
  text-decoration: none;
  color: #111;
  font-weight: 400;
}

.nav-links a:hover {
  text-decoration: underline;
}

.layout {
  max-width: 1100px;
  margin: 20px auto 40px auto;
  padding: 0 20px;
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 60px;
}

.sidebar-inner {
  position: sticky;
  top: 20px;
  padding: 0;
}

.nav-group {
  margin-bottom: 32px;
}

.nav-heading {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: #555;
  margin-bottom: 10px;
}

.sidebar a {
  display: block;
  margin-bottom: 8px;
  text-decoration: none;
  color: #111;
  font-size: 0.95rem;
  font-weight: 400;
}

.sidebar a:hover {
  text-decoration: underline;
}

.content {
  max-width: 740px;
}

.summary {
  margin-bottom: 2em;
}

.site-footer {
  margin-top: 60px;
  padding-top: 20px;
  border-top: 1px solid #e5e5e5;
  font-size: 0.9rem;
  color: #555;
}

.site-footer div {
  margin-bottom: 4px;
}

@media (max-width: 900px) {
  .layout {
    grid-template-columns: 1fr;
  }

  .sidebar-inner {
    position: static;
    margin-bottom: 40px;
  }

  .content {
    max-width: 100%;
  }
}