transparent betterdiscord theme with a nice megumin background

minimalistic_megumin.theme.css

#app-mount {
    
    /* Shinobu */
    /* background-image: url("https://www.walldevil.com/wallpapers/a91/shinobu-oshino-bakemonogatari.jpg"); */
    
    /* Megumin */
    background-image: url('https://images3.alphacoders.com/704/704387.png');
    background-size: cover;

}


/* transparent */
div[class^="layer"], /* Needs to be transparent */
.da-activity > .da-body, /* Currently Playing text*/
.da-category, /* Emoji selector category aka server emojis*/ 
/*.da-channels,  Where the channels are listed */
.da-channels .da-scrollerThemed, /* Discord channels */
.container-2Thooq,.container-2lgZY8, .container-PNkimc,/* Needs to be transparent */
.da-content, /* Messages and member list */
.da-chat, /* Chat and everything to it's right */
.da-flex div[class^="chat"],
.da-headerBar, 
.da-markup:not(.da-isMention), /* Message contents */
.da-scroller, /* All Scrollables */
.da-scrollerFade div[class^="scroller-"], /* All Scrollables */
.da-searchBarLight, /* Emoji searchbar */
.da-recentMentionsPopout .da-header, /* Header inside the recent mentions popup */
.da-themedPopout > .da-header, /* Header inside the pinned messages popup, could have sideeffects. Blame discord */
.da-unread, /* Tell you in which direction you can find new, unread messages */
.stop-animation,
.da-wrapper .da-flexChild,
.da-typing,
div[class^="typing"],
#friends
{ 
    background-color: transparent !important;
}

/* Everthing else */
div[class^="contentHoveredText"], /* Channel entry hovered*/
.da-activityFeed,
.applicationStore-1pNvnv, /*.da-applicationStore, */
.gameLibrary-TTDw4Y, /*.da-library, */
.channels-Ie2l6A,
.da-content form, /* Message Textfield */
.da-divider span, /* Divider between days */
.da-gameLibrary,
.guildsWrapper-5TJh6A, /* .da-guildsWrapper,  Sidebar where the discord servers are displayed */
.da-members, /* Memberlist */
.da-membersWrap,
.da-messagesWrapper, /* Contains the messages */
.da-noChannel,
.da-recentMentionsPopout .da-messageGroupWrapper, /* Message inside recent mentions */
.da-privateChannels .search-bar,
.da-themedPopout .da-messageGroupWrapper,
.friends-table
{
    background-color: RGBA(0, 0, 0, 0.6) !important;
}

/* Appbar */
.da-chat .da-title, /* App bar */
.da-titleWrapper .da-title,
.da-flexChild .da-container,
#friends .da-headerBar {
    background-color: RGBA(0, 0, 0, 0.9) !important;
}

/* 0.6 (Popups)  */
.da-menu, /* online status popup*/
.da-embedInner, /* Embeds */
.da-emojiPicker, /* Emoji picker */
.da-popout section, /* Popup when modifying roles */
.da-themedPopout /* Mentions popup */
{
    background-color: RGBA(0, 0, 0, 0.6) !important;
}

/* 0.7 Darker popups*/
.da-headerNormal, /* User info Popup header*/
.da-headerPlaying, /* User info Popup content*/
.da-userPopout .da-body:not(.da-bodyNormal), /* User info Popup content*/
.da-footer, /* User info Popup footer*/ 
.da-markup pre, /* Markup */
.da-markup pre code /* Markup */
{
    background-color: RGBA(0, 0, 0, 0.7) !important;
}

/* 0.8 (Popup hover, focus, etc.) */
.da-menu .da-item:hover /* online status popup*/
{
    background-color: RGBA(0, 0, 0, 0.8) !important;
}

/* Make things brighter */

/* 0.2 */

form .da-innerNoAutocomplete, /* main Textfield */ 
.da-privateChannels .search-bar .da-searchBarInner,
.da-member .da-content:hover /* Hover over a member inside the memberslist */
{
    background-color: RGBA(255, 255, 255, 0.2) !important;
}

/* 0.4 */ 
.da-footer .da-quickMessage /* Popup Textfield*/
{
    background-color: RGBA(255, 255, 255, 0.4) !important;
}

/* Mention fix */
.da-isMentioned /* The whole markup that contains the message */
{
    background-color: RGBA(100, 100, 50, 0.7) !important;
}

.da-isMentioned .da-markup .da-mention /* The text that mentioned you. E.g. @You */
{
    background-color: RGBA(40, 40, 80, 0.5) !important;
}

/* Fix indent*/
.da-popout header h3 /* Fixes indentation for the textfield where you can search for roles to assign */
{
    margin-left: 4.5em;
}

.da-popout .da-scroller  /* indents the roles inside the popup where you can assign roles */
{
    margin-left: 1em;
}

.friends-table {
    margin-top: 0 !important;
    padding-top: 8px;
}


/* main textfield container fix*/
.da-content form {
    margin: 0 !important;
    padding: 0 20px;
}

/* Emoji select buttons */
#bda-qem, /* The container for the emoji tabs */
#bda-qem-emojis, /* pure discord emojis tab/button */
#bda-qem-favourite, /* ... */
#bda-qem-twitch, /* You can already guess it */
#bda-qem-twitch-container, /* Where the twitch emojis are displayed. Might have broken it */
#bda-qem-favourite-container /* Where the favourites are displayed */
{
    background-color: RGBA(0, 0, 0, 0.5) !important;
}

/* Emoji select buttons */
#bda-qem > .active /* Active category when selecting an emoji */
{
    background-color: black !important;
}

/* Scrollbar */
.theme-dark .messagesWrapper-3lZDfY .scroller-wrap ::-webkit-scrollbar-track-piece,
.bda-dark .emojiPicker-3m1S-j .scroller-3vODG7::-webkit-scrollbar-track-piece 
{
    border-color: transparent;
    background-color: RGBA(50, 50, 50, 0.7);
}

/* Undo border radius */
.da-guildsWrapper,
.da-base {
    border-radius: 0;
}


/* Scrollbar tracker*/
.theme-dark .messagesWrapper-3lZDfY .scroller-wrap ::-webkit-scrollbar-thumb {
    border-color: RGBA(255, 255, 255, 0.0);
    background-color: RGBA(20, 20, 20, 0.7);
}

.stickyHeader-1pqx0j, /* .da-stickyHeader,  Sticky header that tells you the current servers for the emojis */
.da-messageGroupBlocked
{
    display: none !important;
}

div[class*="innerNoAutocomplete-"] {
    background-color: rgba(114,118,125,.15) !important;
}

.guilds {
    background: red !important;
}

/* Custom app headers */

/* Spotify */
.headerSpotify-zpWxgT {
    background-color: RGBA(29, 185, 84, 0.8) !important;
}

/* Xbox */
.headerXbox-3G-4PF {
    background-color: rgba(16, 124, 16, 0.8);
}

.headerXbox-3G-4PF .da-activity .da-body {
    background-color: transparent !important;
}

how tf do u download

doesnt work

It works fine you just have to input it as custom css, you can do it with any

Discord changes their layout all the time, so it would not surprise me if the layout only works partially, if at all. It has been over a year since I've updated this, but I don't use BD nowadays