body {
  font-family: 'Segoe UI', sans-serif;
  background-color: #f0f2f5;
  margin: 0;
  padding: 0;
}

.center-container {
  max-width: 900px;
  margin: 40px auto;
  background: white;
  padding: 30px 40px;
  border-radius: 10px;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
}

h1 {
  font-size: 26px;
  color: #333;
  margin-bottom: 20px;
  text-align: center;
}

h2 {
  font-size: 20px;
  margin-top: 30px;
  color: #444;
}

.note {
  font-size: 14px;
  color: #666;
  margin-bottom: 15px;
  font-style: italic;
}

.upload-form {
  margin-bottom: 25px;
}

.upload-form input[type="file"] {
  margin-bottom: 10px;
}

.submit-button,
.copy-button,
.download-button,
.back-button {
  background-color: #4a90e2;
  color: white;
  border: none;
  padding: 10px 18px;
  font-size: 15px;
  border-radius: 6px;
  margin-right: 10px;
  cursor: pointer;
  transition: background-color 0.2s ease-in-out;
}

.submit-button:hover,
.copy-button:hover,
.download-button:hover,
.back-button:hover {
  background-color: #357ab8;
}

.copy-button.copied {
  background-color: #28a745;
}

.button-group {
  margin-bottom: 15px;
}

#latexContent {
  width: 100%;
  min-height: 400px;
  font-family: 'Courier New', monospace;
  font-size: 15px;
  line-height: 1.6;
  white-space: pre-wrap;
  word-break: break-word;
  padding: 16px;
  background-color: #f9f9f9;
  border: 1px solid #ccc;
  border-radius: 8px;
  resize: vertical;
}