How to make a two-div block with a rubber width?

Question

css

Good afternoon. There are two blocks that should be placed horizontally and be rubber in width. How to do it right?

<div class="b-tab-review__user-list">
        <div class="b-tab-review__user-item">
            <div class="b-tab-review__user-info">
            <p class="b-tab-review__name">Сергей (Уссурийск)</p>
            <p class="b-tab-review__date">18.02.2015</p>
            <p class="b-tab-review__rating">Оценка:
            <ol class="b-tab-review__star-rating_by_user">
                <li class="b-tab-review__star_by_user"></li>
                <li class="b-tab-review__star_by_user"></li>
                <li class="b-tab-review__star_by_user"></li>
                <li class="b-tab-review__star_by_user--nostar"></li>
                <li class="b-tab-review__star_by_user--nostar"></li>
            </ol>
            </p>
            </div>
        </div>
        <div class="b-tab-review__user-item">
            <p class="b-tab-review__review">
                Спасибо! Все понравились, размер подошёл, качество отличное!
                Обязательно куплю еще что-нибудь!
            </p>
        </div>
    </div>

Answer 1

make another block between them and resize the blocks when clinging it with the mouse.

Answer 2

codepen.io/aliencash/pen/GpPQVM
But it seems that the author formulated his question in a wrong way...