.p-bottom-border {
    position: relative;
}

    .p-bottom-border:after {
        content: "";
        position: absolute;
        bottom: -8px;
        left: 0;
        height: 3px;
        width: 20px;
        background-color: #f4ba19;
        transition: all .2s ease;
    }

    .p-bottom-border:hover::after {
        width: 100%;
    }