body {
  font-family: Arial, sans-serif;
  margin: 0;
  background: #f5f5f5;
  color: white;
}

.sub-header {
  background: #2196f3;
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 15px;
  position: relative;
}

.sub-header .back-btn {
  color: white;
  text-decoration: none;
  font-size: 28px;
  position: absolute;
  left: 15px;
  top: 50%;
  transform: translateY(-50%);
}

.sub-header h1 {
  font-size: 22px;
  margin: 0;
}

.intro {
  text-align: center;
  padding: 10px 20px;
}

.intro p {
  font-size: 15px;
  color: #444;
  line-height: 1.6;
}

.motivasi {
  text-align: center;
  padding: 20px;
}

.motivasi p {
  margin: 8px 0;
  font-size: 14px;
  color: #555;
  font-style: italic;
}

.kelas {
  display: flex;
  flex-direction: column;
  align-items: center;
  margin-top: 15px;
  gap: 12px;
}

.btn {
  display: inline-block;
  padding: 10px 20px;
  background: #2196f3;
  color: white;
  text-decoration: none;
  border-radius: 6px;
  font-size: 15px;
  transition: background 0.3s;
  width: 120px;
  text-align: center;
}

.btn:hover {
  background: #1976d2;
}