.header{
    background-image="http://infinityexplorers.com/wp-content/uploads/2016/12/98-UFO-IN-SPACE.jpg";
    padding:20px;
    color:gold;
    font-family:helvetica;
    text-align: center;
}
.column{
    float:left;
    padding:15px;
    margin:10px;
}
#paragr{
    color:blue;
}
#paragr2{
    color:darkblue;
}
.column.left{
    padding: 0px 10px;
    margin:10px 35px;
    background-color:black;
    color:pink;
    text-align:center;
    width:20%;
    height:700px;
}
.column.main{
    margin:5px 35px;
    width:40%;
    background-color:black;
    padding:10px 5px;
    color:white;
    height:700px;
    display:inline-block;
    text-align:center;
}
.column.right{
    padding:10px 10px;
    margin: 5px 20px;
    width:25%;
    text-align:center;
    color:red;
    background-color:black;
    height: 700px;
}
.row:after{
    content:"";
    display:table;
    clear:both;
}

ul{
    list-style-type: none;
    overflow:hidden;
    background-color: black;
}
li{
    text-align:center;
}
li a{
    display:inline-block;
    color:white;
    float:center;
    text-decoration: underline;
    font-size: 20px;
}
li a:hover{
    background-color:grey;
}