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

/* Header */
header {
  text-align: center;
}

/* Table */
.grades {
  text-align: center;
}

/* Form */
.form-section {
  text-align: center;
}