Sightly modified custom Discord CSS based on https://github.com/AlexFlipnote/Discord_MaterialTheme/

custom-material.css

@import "https://rawgit.com/AlexFlipnote/Discord_MaterialTheme/master/theme.css";

/* For Discord_MaterialTheme, replace the default red no-border indicator to white black border circle. */
.guilds-wrapper .guilds .guild.selected.unread:before,
.guilds-wrapper .guilds .guild.selected:before,
.guilds-wrapper .guilds .guild.unread:before {
    background: #eaeaea;
    box-shadow: 0px 1px 0 rgba(0, 0, 0, 0.3), inset 0 1px 0 hsla(0, 0%, 100%, .15);
    border: 1px solid #212121;
    height: 11px;
    width: 11px;
}

/* --- CUSTOM CSS PART --- */
code {
    font-family: "Inziu Iosevka CL", "Inziu Iosevka J"
}

/* Credits to Zoud */
.bot-tag {
    visibility: hidden;
}

.bot-tag:before {
    font-family: "Inziu Roboto J";
    content: "ロトム";
    visibility: visible !important;
    background-color: #2E6DAC;
    font-size: 12px;
    font-weight: 600;
    color: #F38258 !important;
    margin-left: 0px;
    margin-right: -1px;
    padding: 0px 6px;
    -webkit-border-top-right-radius: 3px;
    -webkit-border-bottom-right-radius: 3px;
    border-top-right-radius: 10px;
    border-bottom-right-radius: 10px;
    border-left: 4px solid #F38258;
    text-transform:uppercase;
    vertical-align:bottom;
    line-height:16px;
    -webkit-flex-shrink:0;
    flex-shrink:0;
}

Extra:

/* From Zeta, applies to white-name members */
.user-name:not([style]):after {
    font-family: "Inziu Iosevka CL";
    content: "可耻的白名";
    visibility: visible !important;
    background: transparent;
    font-size: 13px;
    font-weight: 1000;
    color: #fff!important;
    margin-left: 7px;
    margin-right: 0px;
    padding: 1px 3px;
    border: 1px solid white;
    border-radius:3px;
    text-transform:uppercase;
    vertical-align:bottom;
    line-height:16px;
    flex-shrink:0;
}

.private .user-name:after {
    display: none;
}

/* Credits to 110Percent who in turn credits AlexFlipnote, WON'T WORK ON BOTS! */
avatar-small[style*='DISCORD_ID']+.member-inner .member-username .member-username-inner:after,
.avatar-large[style*='DISCORD_ID']+.comment .username-wrapper .user-name:after {
    /* Bot tag code *should* work here */
    content: "quak";
    background: #aaaa22;
    margin-left: 5px;
    font-size: 12px;
    color: #fff;
    padding: 1px 3px;
    border-radius: 4px;
}