on focus form border color css code example

Example 1: focus on input change label color

.input-group {
    display: flex;
    flex-direction: column-reverse;
}

input:focus + label {
    color: red;
}

Example 2: css focus change color

<style>
.dabutton:focus {
    background-color:yellow;
}
</style>
<button class="dabutton"></button> // <-- usage