site / test.css

.tabs {
display: flex;
flex-wrap: wrap;
}
.tabs > input {
display: none;
}
.tabs > input:checked + label + div {
display: block;
}
.tabs > label {
order: 1;
}
.tabs > div {
display: none;
flex-basis: 100%;
order: 2;
}

.tabs {
border: 1px solid;
}
.tabs > input:checked + label {
background-color: gray;
}
.tabs > label {
padding: 10px;
}
.tabs > div {
padding: 10px;
}

body {
background-color: white;
color: black;
}
body.dark {
background-color: black;
color: white;
}