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

body {
	font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
	line-height: 1.6;
	color: #333;
	background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
	min-height: 100vh;
}

.container {
	max-width: 800px;
	margin: 0 auto;
	padding: 20px;
}

header {
	text-align: center;
	margin-bottom: 40px;
	color: white;
}

header h1 {
	font-size: 2.5rem;
	margin-bottom: 10px;
	text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

header p {
	font-size: 1.1rem;
	opacity: 0.9;
}

.worksheet-form {
	background: white;
	padding: 30px;
	border-radius: 15px;
	box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
	margin-bottom: 20px;
}

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

.form-section h2 {
	color: #4a5568;
	margin-bottom: 15px;
	font-size: 1.3rem;
	border-bottom: 2px solid #e2e8f0;
	padding-bottom: 5px;
}

.range-inputs {
	display: grid;
	grid-template-columns: auto 1fr auto 1fr;
	gap: 15px;
	align-items: center;
}

.settings-inputs {
	display: flex;
	flex-direction: column;
	gap: 10px;
}

label {
	font-weight: 600;
	color: #2d3748;
}

input[type="number"] {
	padding: 12px;
	border: 2px solid #e2e8f0;
	border-radius: 8px;
	font-size: 1rem;
	transition: border-color 0.3s ease;
}

input[type="number"]:focus {
	outline: none;
	border-color: #667eea;
	box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

small {
	color: #718096;
	font-style: italic;
}

.form-actions {
	text-align: center;
	margin-top: 30px;
}

.generate-btn {
	background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
	color: white;
	border: none;
	padding: 15px 40px;
	font-size: 1.1rem;
	font-weight: 600;
	border-radius: 10px;
	cursor: pointer;
	transition:
		transform 0.2s ease,
		box-shadow 0.2s ease;
}

.generate-btn:hover {
	transform: translateY(-2px);
	box-shadow: 0 8px 25px rgba(102, 126, 234, 0.3);
}

.generate-btn:active {
	transform: translateY(0);
}

.generate-btn:disabled {
	opacity: 0.6;
	cursor: not-allowed;
	transform: none;
}

.loading {
	text-align: center;
	padding: 40px;
	background: white;
	border-radius: 15px;
	box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

.spinner {
	width: 40px;
	height: 40px;
	border: 4px solid #e2e8f0;
	border-top: 4px solid #667eea;
	border-radius: 50%;
	animation: spin 1s linear infinite;
	margin: 0 auto 20px;
}

@keyframes spin {
	0% {
		transform: rotate(0deg);
	}
	100% {
		transform: rotate(360deg);
	}
}

.error {
	background: #fed7d7;
	color: #c53030;
	padding: 20px;
	border-radius: 10px;
	border-left: 4px solid #e53e3e;
	margin-top: 20px;
}

.hidden {
	display: none;
}

footer {
	text-align: center;
	margin-top: 40px;
	color: white;
	opacity: 0.8;
}

@media (max-width: 768px) {
	.container {
		padding: 10px;
	}

	.range-inputs {
		grid-template-columns: 1fr;
		gap: 10px;
	}

	header h1 {
		font-size: 2rem;
	}

	.worksheet-form {
		padding: 20px;
	}
}