body {
  font-family: "Segoe UI", Tahoma, sans-serif;
  background: #f5f6fa;
  margin: 20px;
  color: #333;
}

/* Заголовки */
#grades-heading {
  color: #2c3e50;
  text-align: center;
  margin-bottom: 20px;
}

h2 {
  text-align: center;
  margin-top: 40px;
  color: #34495e;
}

/* Таблица */
table {
  width: 70%;
  margin: 0 auto 40px auto;
  border-collapse: collapse;
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
  background: white;
  border-radius: 8px;
  overflow: hidden;
}

th {
  background: #2980b9;
  color: white;
  padding: 12px;
  text-transform: uppercase;
  letter-spacing: 1px;
}

td {
  border: 1px solid #ddd;
  padding: 12px;
  text-align: center;
}

tr:nth-child(even) {
  background: #f9f9f9;
}

.highlight-row {
  background: #ffeaa7;
}

/* Форма */
.feedback-form {
  width: 420px;
  margin: 0 auto;
  background: white;
  padding: 25px;
  border-radius: 10px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.feedback-form label {
  font-weight: bold;
  display: block;
  margin-bottom: 5px;
}

.feedback-form input,
.feedback-form select,
.feedback-form textarea {
  width: 100%;
  padding: 10px;
  margin-bottom: 18px;
  border: 1px solid #ccc;
  border-radius: 6px;
  font-size: 14px;
}

.feedback-form textarea {
  resize: vertical;
  min-height: 80px;
}

.feedback-form input[type="radio"] {
  width: auto;
  margin-right: 8px;
}

.feedback-form label input[type="radio"] {
  display: inline-block;
}

.feedback-form button {
  width: 100%;
  padding: 12px;
  background: #2980b9;
  color: white;
  font-size: 16px;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  transition: background 0.3s;
}

.feedback-form button:hover {
  background: #1f6391;
}