body {
	font-family: 'Arial', sans-serif;
	text-align: center;
	background-color: #f0f8ff;
	margin: 0;
	padding: 20px;
	transition: background-color 0.5s;
}

h1 {
	font-size: 2.5rem;
	color: #333;
}

#question {
	font-size: 1.8rem;
	margin: 20px 0;
	font-weight: bold;
	color: #007acc;
}

#input-box {
	font-size: 1.5rem;
	width: 150px;
	padding: 10px;
	text-align: center;
	border-radius: 5px;
	border: 2px solid #007acc;
}

#answer-buttons {
	display: grid;
	grid-template-columns: repeat(3, 70px);
	grid-gap: 10px;
	justify-content: center;
	margin: 20px auto;
}

.answer-btn {
	font-size: 1.3rem;
	padding: 15px;
	cursor: pointer;
	background-color: #007acc;
	color: white;
	border: none;
	border-radius: 5px;
	transition: background-color 0.3s;
}

.answer-btn:hover {
	background-color: #005f99;
}

#submit-btn {
	grid-column: span 3;
	/* 提交按钮占3列 */
	font-size: 1.5rem;
	padding: 10px 20px;
	margin-top: 20px;
	cursor: pointer;
	background-color: #28a745;
	color: white;
	border: none;
	border-radius: 5px;
	transition: background-color 0.3s;
}

#submit-btn:hover {
	background-color: #218838;
}

#result {
	font-size: 1.3rem;
	margin-top: 20px;
	color: #333;
}

#mode-selection {
	margin-bottom: 20px;
}

button.mode-btn {
	font-size: 1.2rem;
	padding: 10px 20px;
	cursor: pointer;
	background-color: #6c757d;
	color: white;
	border: none;
	border-radius: 5px;
	margin: 5px;
	transition: background-color 0.3s;
}

button.mode-btn:hover {
	background-color: #5a6268;
}