* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: 'Microsoft YaHei', 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  line-height: 1.6;
  color: #333;
  background-color: #f5f5f5;
  padding: 20px;
}

.container {
  max-width: 800px;
  margin: 0 auto;
}

h1 {
  text-align: center;
  margin-bottom: 30px;
  color: #2c3e50;
}

.card {
  background-color: #fff;
  border-radius: 8px;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
  padding: 25px;
  margin-bottom: 30px;
}

.form-group {
  margin-bottom: 20px;
}

label {
  display: block;
  margin-bottom: 8px;
  font-weight: bold;
  color: #2c3e50;
}

textarea {
  width: 100%;
  height: 150px;
  padding: 12px;
  border: 1px solid #ddd;
  border-radius: 4px;
  resize: vertical;
  font-family: inherit;
  font-size: 14px;
}

textarea:focus {
  outline: none;
  border-color: #3498db;
  box-shadow: 0 0 0 2px rgba(52, 152, 219, 0.2);
}

#decryptedText {
  background-color: #f9f9f9;
}

.button-group {
  display: flex;
  gap: 10px;
  margin-bottom: 20px;
}

button {
  padding: 10px 20px;
  border: none;
  border-radius: 4px;
  cursor: pointer;
  font-weight: bold;
  transition: background-color 0.3s;
}

#decryptBtn {
  background-color: #3498db;
  color: white;
  flex: 1;
}

#decryptBtn:hover {
  background-color: #2980b9;
}

#clearBtn {
  background-color: #e74c3c;
  color: white;
}

#clearBtn:hover {
  background-color: #c0392b;
}

.info {
  background-color: #fff;
  border-radius: 8px;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
  padding: 25px;
}

.info h3 {
  margin-bottom: 15px;
  color: #2c3e50;
}

.info p {
  margin-bottom: 10px;
}

/* 响应式设计 */
@media (max-width: 600px) {
  .container {
    padding: 10px;
  }
  
  .card, .info {
    padding: 15px;
  }
  
  textarea {
    height: 120px;
  }
}