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

body {
	font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
	background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
	min-height: 100vh;
	display: flex;
	align-items: center;
	justify-content: center;
	padding: 20px;
}

.container {
	background: white;
	border-radius: 20px;
	box-shadow: 0 20px 60px rgba(0, 0, 0, 0.1);
	max-width: 600px;
	width: 100%;
	overflow: hidden;
}

.header {
	background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
	color: white;
	padding: 30px;
	text-align: center;
}

.header h1 {
	font-size: 2.5rem;
	margin-bottom: 10px;
	font-weight: 700;
}

.content {
	padding: 40px;
}

.difficulty-selection {
	text-align: center;
}

.difficulty-selection h2 {
	color: #333;
	margin-bottom: 30px;
	font-size: 1.8rem;
}

.difficulty-buttons {
	display: flex;
	flex-direction: column;
	gap: 15px;
	margin-bottom: 30px;
}

.difficulty-btn {
	background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
	color: white;
	border: none;
	padding: 20px;
	border-radius: 15px;
	font-size: 1.2rem;
	cursor: pointer;
	transition: all 0.3s ease;
	box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.difficulty-btn:hover {
	transform: translateY(-2px);
	box-shadow: 0 8px 25px rgba(0, 0, 0, 0.2);
}

.progress {
	text-align: center;
	margin-bottom: 30px;
	color: #666;
	font-size: 1.1rem;
}

.progress-bar {
	background: #e0e0e0;
	height: 8px;
	border-radius: 4px;
	margin: 10px 0;
	overflow: hidden;
}

.progress-fill {
	background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
	height: 100%;
	transition: width 0.3s ease;
}

.question {
	background: #f8f9fa;
	padding: 30px;
	border-radius: 15px;
	margin-bottom: 30px;
	box-shadow: 0 4px 15px rgba(0, 0, 0, 0.05);
}

.question h3 {
	color: #333;
	font-size: 1.4rem;
	line-height: 1.6;
}

.options {
	display: flex;
	flex-direction: column;
	gap: 15px;
	margin-bottom: 30px;
}

.option {
	background: white;
	border: 2px solid #e0e0e0;
	padding: 20px;
	border-radius: 15px;
	cursor: pointer;
	transition: all 0.3s ease;
	font-size: 1.1rem;
	position: relative;
}

.option:hover {
	border-color: #667eea;
	transform: translateY(-2px);
	box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.option.selected {
	background: #667eea;
	color: white;
	border-color: #667eea;
}

.option.correct {
	background: #28a745;
	color: white;
	border-color: #28a745;
}

.option.incorrect {
	background: #dc3545;
	color: white;
	border-color: #dc3545;
}

.answer-btn {
	background: linear-gradient(135deg, #28a745 0%, #20c997 100%);
	color: white;
	border: none;
	padding: 15px 40px;
	border-radius: 50px;
	font-size: 1.1rem;
	cursor: pointer;
	transition: all 0.3s ease;
	display: block;
	margin: 0 auto;
	box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.answer-btn:hover {
	transform: translateY(-2px);
	box-shadow: 0 8px 25px rgba(0, 0, 0, 0.2);
}

.answer-btn:disabled {
	background: #ccc;
	cursor: not-allowed;
	transform: none;
	box-shadow: none;
}

.explanation {
	background: #e7f3ff;
	border-left: 5px solid #007bff;
	padding: 20px;
	margin: 20px 0;
	border-radius: 8px;
	font-size: 1.1rem;
	line-height: 1.6;
}

.explanation h4 {
	color: #007bff;
	margin-bottom: 10px;
}

.next-btn {
	background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
	color: white;
	border: none;
	padding: 15px 40px;
	border-radius: 50px;
	font-size: 1.1rem;
	cursor: pointer;
	transition: all 0.3s ease;
	display: block;
	margin: 20px auto 0;
	box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.next-btn:hover {
	transform: translateY(-2px);
	box-shadow: 0 8px 25px rgba(0, 0, 0, 0.2);
}

.result {
	text-align: center;
}

.result h2 {
	color: #333;
	margin-bottom: 30px;
	font-size: 2rem;
}

.score {
	background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
	color: white;
	padding: 30px;
	border-radius: 15px;
	margin-bottom: 30px;
	box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.score-item {
	display: flex;
	justify-content: space-between;
	margin-bottom: 15px;
	font-size: 1.2rem;
}

.score-item:last-child {
	margin-bottom: 0;
	font-weight: bold;
	font-size: 1.4rem;
	border-top: 2px solid rgba(255, 255, 255, 0.3);
	padding-top: 15px;
}

.result-buttons {
	display: flex;
	flex-direction: column;
	gap: 15px;
}

.result-btn {
	background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
	color: white;
	border: none;
	padding: 15px 30px;
	border-radius: 50px;
	font-size: 1.1rem;
	cursor: pointer;
	transition: all 0.3s ease;
	box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.result-btn:hover {
	transform: translateY(-2px);
	box-shadow: 0 8px 25px rgba(0, 0, 0, 0.2);
}

.reset-btn {
	background: linear-gradient(135deg, #dc3545 0%, #c82333 100%);
}

.hidden {
	display: none;
}

@media (max-width: 768px) {
	.container {
		margin: 10px;
		border-radius: 15px;
	}

	.header {
		padding: 20px;
	}

	.header h1 {
		font-size: 2rem;
	}

	.content {
		padding: 20px;
	}

	.difficulty-buttons {
		gap: 10px;
	}

	.difficulty-btn {
		padding: 15px;
		font-size: 1.1rem;
	}

	.question {
		padding: 20px;
	}

	.question h3 {
		font-size: 1.2rem;
	}

	.option {
		padding: 15px;
		font-size: 1rem;
	}

	.result-buttons {
		gap: 10px;
	}

	.result-btn {
		padding: 12px 25px;
		font-size: 1rem;
	}
}