Make a theme mobile friendly

[sunlit_skycat]

Hi, I'm a new Dreamwidth user, and I have a community here, at https://blueheronteanook.dreamwidth.org/. I am using the style Radiant Aqua for Venture, with a lot of recolors, set to 3 Columns (one sidebar on each side), one sidebar on each side. I want to be able to make this theme more mobile friendly by having one column only on mobile, essentially the 1 Column (modules at bottom; no sidebar) layout, while keeping the 3 column layout on desktop.

Someone in another community pointed me here. I was given this code, which I copied and pasted into the Custom CSS box, but didn't produce any changes on mobile when I went to check it on Firefox on a Galaxy Note9.

https://gist.github.com/cmho/b3501c8da9ffeb10e903152136a6377d

@media only screen and (max-width: 768px) { /* you can change the pixel width to whatever you want */
    .column-right #content {
        box-sizing: border-box;
    }

    #content {
        padding: 1em;
    }

    .two-columns-right #content, .three-columns-sides #content {
        border: none;
    }

    #content .inner #primary,
    #content .inner #secondary,
    #content .inner #tertiary {
        width: 100%;
        margin: 0;
        float: none;
    }

    .two-columns-left #secondary > .inner:first-child, .three-columns-left #secondary > .inner:first-child, .three-columns-sides #secondary > .inner:first-child, .two-columns-right #tertiary > .inner:first-child, .three-columns-right #tertiary > .inner:first-child, .three-columns-sides #tertiary > .inner:first-child {
        padding: 0;
    }
}

Searching for a theme...

[gaarahiden]

I've been trying to find a link to Juice by @ninetydegrees for SO LONG but I can't find it anywhere :( Does anyone have it? If not, I would love something similar to it.. My favourite parts are the font, colour, and the journal title display.

Here's a link to the one journal that I know has it... Thank you in advance!