lul

body{
    overflow: hidden;
    width: 100vw;
    height: 100vh;
    background-size: cover;
    background-image: url("https://d2v9y0dukr6mq2.cloudfront.net/video/thumbnail/0kjHIH6/animated-cartoon-blue-sky-with-white-clouds_vj92cw5je__F0000.png");
}

.vtak  {
    width:100px;
    height: 100px;
    background-image: url('http://mzayat.com/images/cartoon-bird-clipart-transparent-blue-bird-png-cartoon-picture-cartoon-bird-clipart-6053_4800.png');
    background-position: center;
    background-size:contain;
    background-repeat: no-repeat;
    position: absolute;
}

.slnko{
    width:150px;
    height: 150px;
    position: absolute;
    left:calc(50vw - 75px);
    top:calc(50vh - 75px);
    background-image: url('https://img.clipartxtras.com/7962e5aa9dab6b815b8cfbfb6a8a5106_sun-clipart-with-transparent-background-collection-transparent-sun-clipart_800-766.png');
    background-position:cover;
    background-size:cover;
    background-repeat: no-repeat;
}

ul {
    margin: 0;
    padding: 0;
    background: blue;
    display: inline-block;
}
li {
    padding: 0;
    list-style: none;
    margin: 0;
    display: inline-block;
    border:2px solid black;
    font-size: larger;
}
ul:nth-of-type(even) {
    background: red;
}
ul:nth-of-type(3n) {
    color: white;
    font-weight: bolder;
}
ul:hover{
    background: yellow;
}
li:hover{
    background: green;
}