body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    background-color: #f0f2f5;
    color: #333;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
    background: #1F2937;
}

.container {
    text-align: center;
    background-color: #fff;
    padding: 40px;
    border-radius: 16px;
    box-shadow: 0 10px 20px rgba(0,0,0,0.1), 0 6px 6px rgba(0,0,0,0.1);
    width: 90%;
    max-width: 500px;
    background: #111827;
    border: 1px solid #374151;
}

h1 {
    color: #4f46e5;
    margin-bottom: 20px;
    font-size: 2.5em;
    color: white;
}

.number-display {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin: 30px 0;
}

.number {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    background-color: #e0e7ff;
    color: #4f46e5;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.8em;
    font-weight: bold;
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
    transition: transform 0.3s ease;
}


#generate-btn {
    background-color: #4f46e5;
    color: white;
    border: none;
    padding: 15px 30px;
    font-size: 1.2em;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.3s, box-shadow 0.3s;
    box-shadow: 0 4px 8px rgba(79, 70, 229, 0.4);
}

#generate-btn:hover {
    background-color: #4338ca;
    box-shadow: 0 6px 12px rgba(79, 70, 229, 0.6);

}

.number.generated {
    transform: scale(1.1);
    background-color: #c7d2fe;
}