Check out example codes for "remove box around button when clicked". It will help you in understanding the concepts better.

Code Example 1

* {
	outline: none;
}

Code Example 2

<style>
input[type="button"]
{
    width:120px;
    height:60px;
    margin-left:35px;
    display:block;
    background-color:gray;
    color:white;
    border: none;
    outline:none;
}
</style>

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