body {
    background-color: Yellow;
    border: 2px solid Black;
    border-radius: 16px;
    font-family: verdana;
    margin-left: auto;
    margin-right: auto;
    max-width: 1560px;
    min-width: 256px;
    padding: 24px;
    color: #111111;
    text-align: center;
}
html {
    background-image: linear-gradient(to left, red,orange,yellow,green,blue); 
}
nav ul {
    list-style-type: none;
    background-color: #B577B5;
    border: 4px solid #111111;
    border-radius: 10px;
    font-family: verdana;
    font-weight: bold;
    padding: 16px;
}
nav ul li {
    display: inline;
    border-right: 2px solid #111111;
    padding-right: 8px;
    padding-left: 8px;
}
nav ul li:last-child {
    border-right: none;
}
nav ul li a {
    text-decoration: none;
    color: #111111;
}
nav .selected {
    color:#606060;
}
nav li a:hover {
    text-decoration: underline;
}
img {
    border: 2px solid #111111;
    border-radius: 16px;
}
#game{
    width: 300px;
    height: 500px;
    border: 1px solid black;
    margin: auto;
    box-sizing: border-box;
    overflow: hidden;
}
#character{
    width: 100px;
    height: 100px;
    background-color: red;
    position: relative;
    top: 200px;
    left: 100px;
}
#block1, #block2{
    background-color: black;
    width: 100px;
    height: 100px;
    position: relative;
}
@keyframes slide{
    0%{top:-100px};
    100%{top:500px};
}
#left, #right{
    width:50%;
    position: absolute;
    height: 500px;
}
#right{
    left: 50%;
}
#blocks{
    display: flex;
    top: 500px;
    width: 300px;
    position: relative;
    animation: slide 1s infinite linear;
}
#coin{
    width: 100px;
    height: 100px;
    top: 500px;
    position: relative;
    animation: coinSlide 1s infinite linear;
    animation-delay: 600ms;
    border-radius: 50%;
    background-color: blue;
}
@keyframes coinSlide{
    0%{top:-200px};
    100%{top:400px};
}