A theme which minifies the sides and allows the chat to be bigger.

minified-discord.theme.css

/**
 * @name Minified Dicord
 * @version 1.2
 * @description A theme which minifies the sides and allows for a bigger chat. (You need to have Normalize Classes enabled in the Better Discord settings for the theme to work.)
 * @source https://gist.github.com/Joshix-1/72df7bdf4370191516a6f0761a9bb995
 * @authorId 564843886434975745
 * @author Joshix
**/

/* replies */
.da-repliedMessage .da-username {
    display: none;
}

/*
    right user list
 */
/*shorten right side*/
.da-membersWrap:not(:hover) {
    width: 64px;
    min-width: 64px;
    margin: 0;
}
/*make sure activity and names don't get displayed*/
.da--membersWrap:not(:hover) .da-activity {
    display:none;
}
.da-membersWrap:not(:hover) .da-nameAndDecorators {
    display:none;
}
.da-membersWrap:not(:hover) .da-members {
    width: 100%;
    padding: 0;
}
/*improve minified role names*/
.da-membersWrap:not(:hover) .da-membersGroup {
    padding-left: 5px;
    padding-right: 0;
    margin-right: 0;
    width: 100%;
}
/*role names take up less vertical space*/
.da-membersWrap .da-membersGroup {
    padding-top: 0;
    height: fit-content;
    margin-top: 10px;
}
/*center avatars*/
.da-membersWrap:not(:hover) .da-member {
    padding: 0;
}
/*remove the scroller to have more room.*/
.da-membersWrap:not(:hover) .da-members::-webkit-scrollar {
    width:0;
}

/*categorie names take up less vertical space*/
.da-base .da-content .da-sidebar .da-scroller .da-content .da-containerDefault {
    padding-top: 0;
    height: fit-content;
}
/* fix voice chat*/
#channels div.list-2luk8a.list-SuzGBZ.listDefault-3ir5aS {
    padding: 0;
}
/* fix channels */
#channels > div > div > div > div {
    padding: 0;
}

#channels  .containerDefault-3tr_sE {
    padding: 0;
}

/* show voice state buttons*/
#app-mount > div.app-1q1i1E > div > div.layers-3iHuyZ.layers-3q14ss > div > div > div > div > div.sidebar-2K8pFh > section > div.container-3baos1 > div.flex-1xMQg5.flex-1O1GKY.horizontal-1ae9ci.horizontal-2EEEnY.flex-1O1GKY.directionRow-3v3tfG.justifyStart-2NDFzi.alignStretch-DpGPf3.noWrap-3jynv6 {
    display: inherit;
    opacity: 100;
    padding: 0;
}

/* make voice state buttons small if not hovering */
#app-mount > div.app-1q1i1E > div > div.layers-3iHuyZ.layers-3q14ss > div > div > div > div > div.sidebar-2K8pFh > section > div.container-3baos1 > div.flex-1xMQg5.flex-1O1GKY.horizontal-1ae9ci.horizontal-2EEEnY.flex-1O1GKY.directionRow-3v3tfG.justifyStart-2NDFzi.alignStretch-DpGPf3.noWrap-3jynv6:not(:hover) button {
    width: 23px;
    height: 23px;
}