How to tab arrangement in css drupal 8

Go on your browser and click to inspect  see

and then see the id like "id='block-itpalce-local-tasks'" this id is call to all inner pages
go to style.css copy and past

Demo style.css
#block-itplace-local-tasks ul {
    float: left;
    width: 100%;
    margin: 0 0 10px;
    padding: 0;
    position: relative;
    z-index: 1;
    pointer-events: none;
}
#block-itplace-local-tasks {
    display: flex;
}
#block-itplace-local-tasks ul li {
    float: left;
    margin-right: 5px;
    margin-left: 0;
    pointer-events: initial;
}
#block-itplace-local-tasks ul li {
    display: inline;
    margin: 0 10px;
}
#block-itplace-local-tasks ul li a:hover, #block-itplace-local-tasks ul li a.is-active {
    background-color: #FFFFFF;
    background-image: none;
    border-left: 1px solid #E8E8E8;
    border-left-style: solid;
    border-left-width: 1px;
    border-right: 1px solid #E8E8E8;
    border-right-style: solid;
    border-right-width: 1px;
    border-style: solid solid none;
    border-top-style: solid;
    border-top: 1px solid #E8E8E8;
    border-top-width: 1px;
    border-width: 1px 1px 0;
    display: block;
    height: 37px;
    line-height: 36px;
    padding-left: 25px;
    padding-right: 25px;
}
#block-itplace-local-tasks ul li a {
    border: 1px solid #ccc;
    color: #003b71;
    display: block;
    height: 36px;
    line-height: 36px;
    padding-left: 25px;
    padding-right: 25px;
    background-color: #eee;
    text-decoration: none;
}