* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
}
body {
  background-color: white;
  color: black;
}

header {
  background: blue;
  color: white;
  padding: 1rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
nav ul {
  display: flex;
  list-style: none;
}
nav ul li a {
  color: orange;
  margin-left: 20px;
  text-decoration: none;
}
nav ul li a.active {
  border-bottom: 2px solid darkblue;
}

.grid-container {
  display: grid;
  grid-template-columns: repeat(autofill, minimax(250px, 1fr));
  gap: 20px;
  padding: 20px;
}

.course-card {
  background: black;
  padding: 15px;
  border-radius: 8px;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 1);
}

.form-section {
  max-width: 500px;
}

.form-group {
  margin-bottom: 15px;
}

input {
  width: 100%;
  padding: 8px;
  margin-top: 5px;
}
.error {
  color: red;
  font-size: 0.8rem;
}
@media (max-width: 600px) {
  header {
    flex-direction: column;
    text-align: center;
  }
  nav ul {
    margin-top: 10px;
  }
}

.info-section {
  max-width: 800px;
  margin: 40px auto;
  padding: 20px;
  line-height: 1.6;
}
.stats-box {
  background: white;
  border-left: 5px solid lightskyblue;
  padding: 20px;
  margin: 20px 0;
  border-radius: 4px;
}
.info-section h3 {
  margin-top: 20px;
  color: darkblue;
}
.info-section ul {
  margin-left: 20px;
}