simple-slack.css

/* Set the grid to display only primary/secondary view in focus mode */
.p-workspace {
    grid-template-columns: auto;
    grid-template-rows: auto;
    grid-template-areas: "p-workspace__primary_view p-workspace__secondary_view";
    margin-top: 3vh;
}
.p-workspace__banner, .p-workspace__top_nav, .p-workspace__sidebar, .p-client__team_sidebar {
    display:none;
}
.p-client--show-team-sidebar {
    grid-template-columns: 0 auto;
}

/* Primary view focus mode (full width) */
.p-workspace__primary_view {
    width: 100vw;
}

/* Secondary view focus mode (full width, fixed, z-indexed in front of primary view, background color set) */
.p-workspace__secondary_view {
    position: fixed;
    width: 100vw;
    height: 98vh;
    bottom: 0;
    left: 0;
    border-left: none;
    z-index: 200;
    background: rgb(255,255,255);
}

/* Dark mode background for secondary view */
.sk-client-theme--dark .p-workspace__secondary_view {
    background: rgb(26,29,33);
}

.sk-client-theme--dark .c-virtual_list__item button.c-reaction > img,
.sk-client-theme--dark .c-virtual_list__item div.c-aspect_box__content > a,
.sk-client-theme--dark .c-virtual_list__item span.c-emoji > img,
.sk-client-theme--dark .c-virtual_list__item span img.c-emoji,
.sk-client-theme--dark .c-virtual_list__item span.c-emoji img,
.sk-client-theme--dark .p-emoji_picker__list_item > img {
    background-repeat: no-repeat;
    background-position: 50%;
    background-size: contain;
}

/* Prevent typing in primary_view when secondary_view (threads) is open */
.p-workspace--context-pane-expanded .p-workspace__primary_view .ql-editor {
    display: none;
}

/* Make preferences page (and other full screen modals) take up the full width in focus mode */
.p-prefs_modal--sidebar-open-multi-team {
    left: 0;
}
.p-prefs_modal {
    left: 0;
}

/* Hide gifs except on hover/focus */
.c-virtual_list__item div.c-aspect_box__content > a[href$=".gif"],
.c-virtual_list__item button.c-reaction > img[src$=".gif"],
.c-virtual_list__item span.c-emoji > img[src$=".gif"],
.c-virtual_list__item span img.c-emoji[src$=".gif"],
.c-virtual_list__item span.c-emoji img[src$=".gif"]
{
    visibility: hidden;
}
.c-virtual_list__item:hover div.c-aspect_box__content > a[href$=".gif"],
.c-virtual_list__item:focus div.c-aspect_box__content > a[href$=".gif"],
.c-virtual_list__item:hover button.c-reaction > img[src$=".gif"],
.c-virtual_list__item:focus button.c-reaction > img[src$=".gif"],
.c-virtual_list__item:hover span.c-emoji > img[src$=".gif"],
.c-virtual_list__item:focus span.c-emoji > img[src$=".gif"],
.c-virtual_list__item:hover span img.c-emoji[src$=".gif"],
.c-virtual_list__item:focus span img.c-emoji[src$=".gif"],
.c-virtual_list__item:hover span.c-emoji img[src$=".gif"],
.c-virtual_list__item:focus span.c-emoji img[src$=".gif"]
{
    visibility: visible;
}