active tab background change in color when css is applied

Hello. I’m using a tab element on my site and on mobile, the active tab background is set to none, but I want it to be #378084. I tried using

.main_color .template-archives .tabcontainer a, #top .main_color .tabcontainer .tab:hover, #top .main_color .tabcontainer .tab.active_tab {
background-color: #378084 !important;
}

but it didn’t work. Thanks in advance