*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
body{
    width: 100%;
    height: 200vh;
    background-color: #efefef;

}
img,video{
    width: 100%;
}
a,a:active,a:link,a::before,a::after{
    color: black;
    text-decoration: none;

}
ul{
    list-style: none;
}