body {
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 0;
  line-height: 1.6;
  background: #f4f4f4;
}

/* Header */
header {
  background: #333;
  color: white;
  padding: 1rem;
  text-align: center;
}

/* Table */
.grades {
  padding: 2rem;
  text-align: center;
}
table {
  width: 60%;
  margin: auto;
  border-collapse: collapse;
  background: white;
}
th, td {
  border: 1px solid #ddd;
  padding: 0.8rem;
}
th {
  background: #333;
  color: white;
}
tr:nth-child(even) {
  background: #f9f9f9;
}

/* Form */
.form-section {
  padding: 2rem;
  text-align: center;
}
form {
  max-width: 400px;
  margin: auto;
  display: flex;
  flex-direction: column;
  background: white;
  padding: 1rem;
  border-radius: 5px;
}
form input {
  padding: 0.5rem;
  margin: 0.5rem 0;
  border: 1px solid #ccc;
  border-radius: 4px;
}
form button {
  background: #333;
  color: white;
  border: none;
  padding: 0.6rem;
  margin-top: 1rem;
  border-radius: 4px;
  cursor: pointer;
}
form button:hover {
  background: #555;
}

/* Footer */
footer {
  background: #333;
  color: white;
  text-align: center;
  padding: 1rem;
}