/* Base */
* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: Arial, sans-serif;
  background-color: #f5f5f5;
  color: #333;
}

a {
  color: #2980b9;
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

/* Top bar */
.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 24px;
  background-color: #2c3e50;
  color: #fff;
}

.topbar .brand {
  font-size: 20px;
  font-weight: bold;
}

.topbar nav a {
  margin-left: 18px;
  color: #ecf0f1;
  font-weight: 500;
}

/* Main layout */
.page-layout {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 20px;
  max-width: 1000px;
  margin: 24px auto;
  padding: 0 16px;
}

.sidebar {
  background: #fff;
  border-radius: 8px;
  padding: 16px;
  height: fit-content;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
}

.sidebar h2 {
  margin-top: 0;
  color: #34495e;
  font-size: 18px;
}

.sidebar ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.sidebar li {
  margin: 10px 0;
}

.content {
  background: #fff;
  border-radius: 8px;
  padding: 24px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
}

h1 {
  margin-top: 0;
  color: #2c3e50;
}

h2 {
  color: #34495e;
  margin-top: 24px;
}

p {
  line-height: 1.6;
}

/* Footer */
.footer {
  text-align: center;
  padding: 18px;
  background-color: #ecf0f1;
  color: #555;
  margin-top: 24px;
}

/* Responsive */
@media (max-width: 768px) {
  .page-layout {
    grid-template-columns: 1fr;
  }

  .topbar {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
  }

  .topbar nav a {
    margin-left: 0;
    margin-right: 12px;
  }
}