.col {
    margin-top: 12px;
    display: inline-block;
    position: relative;
}

.textbox {
    border: 0;
    padding: 2px 0;
    border-bottom: 1px solid #ccc;
    font: 13px/24px "Lato", Arial, sans-serif;
    color: #333;
    width: 275px;
    box-sizing: border-box;
    letter-spacing: 1px;
}

    .textbox ~ .focus-border {
        position: absolute;
        bottom: 0;
        left: 50%;
        width: 0;
        height: 2px;
        background-color: #3399FF;
        transition: 0.4s;
    }

    .textbox:focus {
        outline: none;
    }

        .textbox:focus ~ .focus-border {
            width: 100%;
            transition: 0.4s;
            left: 0;
        }