style.css

* {
outline:none;
user-select: none;
}

body {
margin:0;
padding:0;
height:100vh;
display:flex;
flex-direction:column;
}

.nav {
height:10vh;
width:100%;
background:#0079ff;
margin:0;
display:flex;
justify-content:ceneter;
align-self:center;
position:sticky;
top:0;
}

.nav div {
height:100%;
width:100%;
display:flex;
align-items:center;
box-sizing:border-box;
padding:1rem;
}

.nav div>span {
font-size:1.3rem;
font-weight:300;
color:white;
}

.root {
height:100%;
width:100%;
background:transparent;
flex:1;
}

.tabs {
width:100%;
height:10vh;
background:#0078ff;
display:flex;
align-items:center;
position:sticky;
top:0;
}

.tabs .btn {
height:100%;
width:50%;
background:transparent;
border:none;
color:#fcfcfc;
border-bottom:3px solid #0078ff;
}

.tabs .btn.active {
border-bottom:3px solid #fff;
}