* {
    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;
    padding: 20px;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    background: white;
    border-radius: 10px;
    box-shadow: 0 10px 40px rgba(0,0,0,0.2);
    padding: 40px;
}

h1 {
    color: #333;
    margin-bottom: 10px;
    font-size: 28px;
}

h2 {
    color: #667eea;
    font-size: 20px;
    margin-bottom: 20px;
}

.intro {
    background: #f8f9fa;
    padding: 20px;
    border-left: 4px solid #667eea;
    margin-bottom: 30px;
    border-radius: 5px;
}

.intro p {
    margin-bottom: 10px;
    line-height: 1.6;
    color: #555;
}

.intro p:last-child {
    margin-bottom: 0;
    font-weight: bold;
}

.question {
    margin-bottom: 25px;
    padding: 20px;
    background: #f8f9fa;
    border-radius: 8px;
    transition: all 0.3s ease;
}

.question:hover {
    background: #e9ecef;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.question-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 15px;
}

.question-number {
    background: #667eea;
    color: white;
    width: 35px;
    height: 35px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    flex-shrink: 0;
}

.question-text {
    flex: 1;
    color: #333;
    line-height: 1.6;
    padding-top: 5px;
}

.question-input {
    flex-shrink: 0;
}

input[type="number"] {
    width: 80px;
    padding: 10px;
    border: 2px solid #ddd;
    border-radius: 5px;
    font-size: 16px;
    text-align: center;
    transition: all 0.3s ease;
}

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

input[type="number"]:invalid {
    border-color: #dc3545;
}

.button-container {
    text-align: center;
    margin-top: 30px;
}

button {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    padding: 15px 50px;
    font-size: 18px;
    border-radius: 50px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: bold;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

button:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.6);
}

button:active {
    transform: translateY(0);
}

.error-message {
    color: #dc3545;
    background: #f8d7da;
    padding: 15px;
    border-radius: 5px;
    margin-top: 20px;
    display: none;
    border-left: 4px solid #dc3545;
}

@media (max-width: 768px) {
    .container {
        padding: 20px;
    }
    
    h1 {
        font-size: 24px;
    }
    
    h2 {
        font-size: 18px;
    }
    
    .question-header {
        flex-direction: column;
        gap: 10px;
    }
    
    .question-input {
        width: 100%;
    }
    
    input[type="number"] {
        width: 100%;
    }
}