*{
    margin:0;
    padding:0;
    box-sizing:border-box;
    font-family:Arial,sans-serif;
}
body{
    overflow: auto;
}
/*loading screen*/
#loading-screen{
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: black;
    opacity: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    color: white;
    z-index: 9999;
}
#logo{
    width: 150px;
    margin-bottom: 20px;
    animation: spin 2s linear;
}
@keyframes spin {
    0% { transform: rotate(0deg);}
    100% { transform: rotate(360deg);}
}
/*main content*/
#mainContent{
    display: none;
    text-align: center;
    padding: 50px;
}