* {
    margin: 0;
    padding: 0;
}

body {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background-color: #000;
}

#container {
    background-color: #ffff;
    border: 2px solid #000;
    border-radius: 15px;
    max-width: 100%;
    padding: 2rem;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 12px;
}

#hex-number {
    font-family: Cambria, Cochin, Georgia, Times, 'Times New Roman', serif;
    font-size: 4rem;
}

#change-color-btn {
    color: #ffff;
    font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    font-size: 1rem;
    font-weight: bold;
    padding: 10px;
    border: none;
    border-radius: 15px;
    background-color: #000;
    cursor: pointer;
}