Change "equal height" to "individual height" in mobile version

Hi everyone
I have set some of my rows to adjust to “equal height columns”. In the mobile version I however want to transform these to ”individual height columns” in order to get rid of unnecessary whitespace as the whitespace is disturbing when boxes get stacked in the mobile version.
Is there a way to achieve this?
I´m grateful for any help.

P.S. I tried to use:
@media only screen and (max-device-width: 736px) {
.responsive #top #wrap_all .flex_column {
margin-bottom: 0px !important;
}}

but it does´t change anything…