body {
    object-fit: contain;
    background-size: contain;
    font-family: Arial, Helvetica, sans-serif;
    background-image: radial-gradient(circle, #004a67 40%, #0e020f 100%);

    
}
#timeline {
    content: '';
    position: absolute;
    background: white;
    width: 1px;
    left: 50%;
}

.child {
    position: relative;
    margin: 30px;
    opacity: 0;
}

.child:nth-child(odd) {
    float: left;
    border-radius: 20px 0px 20px 20px;
    text-align: left;
    box-shadow: 0 4px 30px rgba(0,0,0);
    backdrop-filter: blur(5px);
    -webkit-backdrop-filter:blur(5px);
    border: 1px solid rgba(255,255,255,0.3);
}

.child:nth-child(even) {
    float: right;
    border-radius: 20px 0px 20px 20px;
    text-align: left;
    box-shadow: 0 4px 30px rgba(0,0,0,0.1);
    backdrop-filter: blur(5px);
    -webkit-backdrop-filter:blur(5px);
    border: 1px solid rgba(255,255,255,0.3);
}
footer{
    bottom: 0;
    position: fixed;
    width: 100%;
    margin-top: 50px;
}
.child:nth-child(even)::before {
    content: '';
    position: absolute;
    background: white;
    border-radius: 50%;
    width: 20px;
    height: 20px;
    right: -30px;
}

.child:nth-child(odd)::before {
    content: '';
    position: absolute;
    background: white;
    border-radius: 50%;
    width: 20px;
    height: 20px;
    left: -30px;
}
.child:nth-child(odd)::after {
    content: '';
    position: absolute;
    background: white;
    width: 10px;
    height: 2px;
    left: -10px;
    top: 10px;
}
.child:nth-child(even)::after {
    content: '';
    position: absolute;
    background: white;
    width: 10px;
    height: 2px;
    right: -10px;
    top: 10px;
}
.content {
    width: 400px;
    padding: 15px;
    color: white;
    background: rgb(255, 255, 255, 0.2);
}

._show{
opacity: 1;
animation: __show 1s cubic-bezier(.99,-.7,.2,1.9);
}
._hide{
    opacity: 0;
    animation: __hide 1s cubic-bezier(.99,-.7,.2,1.9);
}
@keyframes __show{
    0% {transform :translateY(500px); opacity:0;}
    100% {transform :translateY(0); opacity:1;}
}
@keyframes __hide{
    0% {transform :translateY(0px); opacity:1;}
    100% {transform :translateY(500px); opacity:0;}
}