I found the solution:
.flex-container{ display: flex; overflow-y: scroll;}.flex-container > div{ margin: auto; }html,body{ height: 100%; width: 100%; padding: 0; margin: 0;}.flex-container{ display: flex; width: 100%; height: 100px; overflow-y: scroll; background: #2a4;}.flex-container > div{ padding: 1em 1.5em; margin: auto; background: #E77E23; width: 400px;}<div > <div>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Iure fugit voluptas eius nemo similique aperiam quis ut! Ipsa aspernatur rem nesciunt est sed hic culpa nisi delectus error explicabo reprehenderit. Lorem ipsum dolor sit amet, consectetur adipisicing elit. Iure fugit voluptas eius nemo similique aperiam quis ut! Ipsa aspernatur rem nesciunt est sed hic culpa nisi delectus error explicabo reprehenderit. </div></div>
