You can custom the outline of the component when you focus on it. CSS allows you to custom these properties:
outline-color
outline-style
outline-width
The order of these properties doesn't matter. You can use just one, two, or all three of them.
For example:
button {
background: tomato;
color: white;
border: none;
}
button:focus {
outline: blue dotted 5px;
}
When you click the button, you will see the blue dotted outline around the button.
The outline doesn't take up space. It won't affect the layout when it shows up.