body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, sans-serif;
  background: #f8fafc; /* soft light gray */
  color: #0f172a; /* dark slate text */
}

.container {
  max-width: 900px;
  margin: 40px auto;
  padding: 0 20px;
}

.topbar {
  display: flex;
  justify-content: space-between;
  padding: 20px 40px;
  background: white;
  border-bottom: 1px solid #e2e8f0;
}

.topbar a {
  color: #475569;
  margin-left: 20px;
  text-decoration: none;
  font-weight: 500;
}

.topbar a:hover {
  color: #0f172a;
}

.nav-left {
  font-weight: 600;
  color: #0f172a;
}

h1 {
  font-size: 2.5rem;
  color: #020617;
}

.card {
  background: white;
  padding: 20px;
  margin: 20px 0;
  border-radius: 12px;
  border: 1px solid #e2e8f0;
  transition: all 0.2s ease;
}

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 20px;
}

.card:hover {
  border-color: #38bdf8;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.04);
}

.button {
  display: inline-block;
  padding: 10px 16px;
  background: #0f172a;
  color: white;
  border-radius: 8px;
  text-decoration: none;
  margin-top: 10px;
  font-weight: 500;
}

.button:hover {
  background: #1e293b;
}

a:visited {
  color: inherit; 
}

.course-list {
  list-style: none;
  padding: 0;
  margin-top: 12px;
}

.course-list li {
  padding: 6px 0;
  border-bottom: 1px solid #e2e8f0;
  line-height: 1.4;
}

.course-list li:last-child {
  border-bottom: none;
}