.hashtag {
    &:empty {
        &::after {
            content: "#";
            line-height: 0;
            font-size: 18px;
            font-weight: 700;
        }
    }
}

.left-sidebar-title {
    color: var(--color-text-sidebar-heading);
    opacity: var(--opacity-sidebar-heading);
    transition: opacity 140ms linear;
    font-size: inherit;
    font-weight: var(--font-weight-sidebar-heading);
    letter-spacing: var(--letter-spacing-sidebar-heading);
    /* Override heading margin from Bootstrap. */
    margin: 0;
    /* Show an ellipsis on a heading when
       it won't sit adjacent other icons
       or controls in the row. */
    overflow: hidden;
    text-overflow: ellipsis;
}

.sidebar-topic-check,
.topic-markers-and-controls {
    cursor: pointer;
}

#left-sidebar-navigation-list .filter-icon i {
    color: var(--color-left-sidebar-navigation-icon);
}

#stream_filters,
#left-sidebar-navigation-list {
    margin-right: var(--left-sidebar-right-margin);
}

#streams_inline_icon,
.streams_filter_icon {
    opacity: 0.5;

    &:hover {
        opacity: 1;
        cursor: pointer;
    }
}

.streams_filter_icon.web_public {
    margin-right: 10px;
}

.tooltip {
    max-width: 18em;
}

#stream_filters {
    overflow: visible;
    margin-bottom: 5px;
    padding: 0;
    font-weight: normal;

    .topic_search_section {
        margin: 3px 0;

        .clear_search_button {
            grid-area: row-content;
            justify-self: self-end;
            /* Override app-component positioning. */
            position: static;
            padding-right: 4px;
        }
    }

    & li {
        & .sidebar-topic-name:hover {
            text-decoration: none;
        }

        & ul {
            margin-left: 0;

            &.topic-list li {
                padding: 0;
            }
        }
    }

    .stream-with-count.hide_unread_counts {
        .masked_unread_count {
            display: block;
            /* Shift masked dot to align with
               the least-significant digit on
               unreads in other rows.
               We have to do this with margin,
               because width or padding will
               distort the CSS-created dot. */
            margin-right: var(--masked-unread-count-margin-right);
        }

        .unread_count {
            display: none;
        }
    }

    .narrow-filter
        > .bottom_left_row:hover
        > .stream-with-count.hide_unread_counts {
        .masked_unread_count {
            display: none;
        }

        .unread_count {
            display: inline;
        }
    }

    .stream-expanded {
        .stream-with-count.hide_unread_counts {
            .masked_unread_count {
                display: none;
            }

            .unread_count {
                display: inline;
            }
        }
    }

    .has-unmuted-unreads.hide_unread_counts {
        .masked_unread_count {
            display: none;
        }

        .unread_count {
            display: inline;
        }
    }

    .inactive_stream:not(.active-filter) {
        opacity: 0.5;
    }

    .toggle_stream_mute {
        margin-right: 3px;
        opacity: 0.5;

        &:hover {
            opacity: 1;
        }
    }
}

.left-sidebar-navigation-area {
    & li a {
        &:hover {
            text-decoration: none;
        }
    }
}

#left_sidebar_scroll_container {
    outline: none;
    overflow: hidden auto;
    position: relative;
    z-index: 0;
    width: 100%;

    .direct-messages-container {
        margin-left: 0;
    }
}

#direct-messages-section-header {
    grid-template-columns:
        0 var(--left-sidebar-header-icon-toggle-width) 0 minmax(0, 1fr)
        max-content 30px 0;
    grid-template-rows: var(--line-height-sidebar-row-prominent);
    cursor: pointer;
    white-space: nowrap;
    border-radius: 4px;

    /* Prevent hover styles set on other rows when zoomed in. */
    &:not(.zoom-in):hover {
        background-color: var(--color-background-hover-narrow-filter);
        box-shadow: inset 0 0 0 1px var(--color-shadow-sidebar-row-hover);

        .left-sidebar-title,
        .sidebar-heading-icon {
            opacity: var(--opacity-sidebar-heading-hover);
        }
    }

    #toggle-direct-messages-section-icon {
        grid-area: starting-anchor-element;
        /* Horizontally center the icon in its allotted grid area. */
        justify-self: center;
    }

    .left-sidebar-title {
        grid-area: row-content;
    }

    .heading-markers-and-controls {
        grid-area: markers-and-controls;
        display: flex;
        gap: 5px;
        align-items: center;
    }

    #show-all-direct-messages {
        width: var(--left-sidebar-header-icon-width);
        display: flex;
        align-items: center;
        justify-content: center;
        opacity: 0.7;
        text-decoration: none;
        color: inherit;

        &:hover {
            opacity: 1;
        }
    }
}

.direct-messages-container {
    /* Properly offset all the grid rows
       in the DM section. */
    margin-right: var(--left-sidebar-right-margin);

    & ul.dm-list {
        list-style-type: none;
        font-weight: 400;
        margin-left: 0;
        margin-bottom: 0;
        line-height: var(--line-height-sidebar-row-prominent);

        & li.dm-list-item {
            & a {
                text-decoration: none;
                color: inherit;
            }

            .zulip-icon {
                opacity: 0.7;
            }
        }

        & li#show-more-direct-messages {
            color: var(--color-text-sidebar-action-heading);
            font-size: var(--font-size-sidebar-action-heading);
            font-weight: var(--font-weight-sidebar-action-heading);
            letter-spacing: var(--letter-spacing-sidebar-action-heading);
            font-variant: var(--font-variant-sidebar-action-heading);
            text-transform: var(--text-transform-sidebar-action-heading);
            cursor: pointer;
            /* The 'more conversations' line has no icons,
               so vertically align the text with the unread
               count, when one appears there. */
            align-items: baseline;

            &:hover {
                background-color: var(
                    --color-background-sidebar-action-heading-hover
                );

                .dm-name {
                    color: var(--color-text-sidebar-action-heading-hover);
                }
            }

            .unread_count {
                margin-top: 2px;
            }
        }
    }
}

.zulip-icon-heading-triangle-right {
    transition:
        opacity 140ms linear,
        rotate 140ms linear;
}

.zulip-icon-heading-triangle-right.rotate-icon-down {
    rotate: 90deg;
}

.zulip-icon-heading-triangle-right.rotate-icon-right {
    rotate: 0deg;
}

#toggle-direct-messages-section-icon,
#toggle-top-left-navigation-area-icon {
    color: var(--color-text-sidebar-heading);
    opacity: var(--opacity-sidebar-heading-icon);

    &:focus {
        outline: 0;
    }

    /* This renders an outline when the caret is reached
       with the keyboard, although that is not at present
       easily accomplished. */
    &:focus-visible {
        outline: 2px solid var(--color-outline-focus);
    }
}

.active-direct-messages-section {
    background-color: var(--color-background-active-narrow-filter);

    #direct-messages-section-header {
        border-radius: 4px 4px 0 0;
    }

    #direct-messages-list {
        border-radius: 0 0 4px 4px;
    }
}

.top_left_row,
.bottom_left_row {
    /* Ensure a border radius on any interactive
       state that might show a highlight. */
    border-radius: 4px;

    &:hover,
    &:has(.left_sidebar_menu_icon_visible) {
        background-color: var(--color-background-hover-narrow-filter);
        box-shadow: inset 0 0 0 1px var(--color-shadow-sidebar-row-hover);

        .sidebar-topic-check {
            background-color: var(
                --color-background-opaque-hover-narrow-filter
            );
        }
    }

    &:has(.sidebar-topic-action-heading):hover {
        background-color: var(--color-background-sidebar-action-heading-hover);
    }

    &.active-filter,
    &.active-sub-filter {
        &:has(.left_sidebar_menu_icon_visible) {
            background-color: var(--color-background-active-narrow-filter);
        }
    }
}

#stream_filters .narrow-filter.highlighted_stream {
    &.active-filter > .bottom_left_row {
        background-color: var(--color-background-hover-narrow-filter);
    }

    &.active-filter .topic-list .bottom_left_row {
        background-color: var(--color-background-active-narrow-filter);
    }

    .bottom_left_row:not(.active-sub-filter) {
        background-color: var(--color-background-hover-narrow-filter);
    }
}

#login-link-container,
#subscribe-to-more-streams {
    text-decoration: none;
    margin: 5px auto var(--left-sidebar-bottom-scrolling-buffer)
        var(--left-sidebar-toggle-width-offset);

    .subscribe-more-icon {
        min-width: 19px;
        text-align: center;

        &::before {
            padding-right: 3px;
        }
    }
}

#login-link-container {
    color: var(--color-text-url);
    display: flex;
    align-items: center;

    &:hover {
        cursor: pointer;
        color: var(--color-text-url-hover);

        &.login_button .login-text {
            color: var(--color-text-url-hover);
            text-decoration: underline;
        }
    }
}

ul.filters {
    list-style-type: none;
    margin-left: 0;
    /* Streams take a standard row height. */
    line-height: var(--line-height-sidebar-row);

    .sidebar-topic-name,
    .left-sidebar-navigation-label-container {
        color: var(--color-text-sidebar-row);

        &:hover {
            /* Push back against a:hover color in dark_theme.css */
            color: var(--color-text-sidebar-row) !important;
        }

        &:focus {
            text-decoration: none;
        }
    }

    & hr {
        margin-top: 10px;
        margin-bottom: 10px;
    }

    .has-only-muted-unreads {
        .unread_count {
            opacity: 0.5;
        }
    }

    .has-only-muted-mentions .unread_mention_info {
        opacity: 0.5;
    }

    /* This is a noop in the current design, because unread counts for
       muted streams have the same opacity, but the logic is here to
       be explicit and because the design may change in the future. */
    .more_topic_unreads_muted_only .unread_count {
        opacity: 0.5;
    }

    .zulip-icon-follow {
        opacity: 0.6;

        &:hover {
            opacity: 1;
            color: var(--color-left-sidebar-follow-icon-hover);
        }
    }

    & li.muted_topic,
    li.out_of_home_view {
        color: hsl(0deg 0% 20% / 50%);

        .has-unmuted-mentions .unread_mention_info {
            color: hsl(0deg 0% 20%);
        }

        .stream-privacy {
            opacity: 0.5;
        }

        & .unread_count {
            opacity: 0.5;
        }

        & .masked_unread_count {
            opacity: 0.5;
        }

        .has-unmuted-unreads {
            .unread_count {
                opacity: 1;
            }
        }

        & li.unmuted_or_followed_topic {
            color: var(--color-unmuted-or-followed-topic-list-item);

            .unread_count {
                opacity: 1;
            }
        }
    }

    & li.out_of_home_view {
        &:hover {
            color: hsla(0deg 0% 20% / 75%);

            .stream-privacy {
                opacity: 0.75;
            }

            .unread_count {
                opacity: 0.75;
            }

            .has-unmuted-unreads {
                .unread_count {
                    opacity: 1;
                }
            }
        }

        & li.muted_topic {
            /* If stream is muted, this resets opacity of muted topics in muted
            stream to 1; since opacity is multiplied down through child
            elements, this avoids an unreadably low opacity. */
            opacity: 1;
        }
    }
}

li.active-filter,
li.active-sub-filter {
    font-weight: 600 !important;
    position: relative;
    border-radius: 4px;
    color: var(--color-text-active-narrow-filter);
    background-color: var(--color-background-active-narrow-filter);

    &:hover {
        background-color: var(--color-background-active-narrow-filter);

        .sidebar-topic-check {
            /* This variable is only set and used in dark mode. */
            background-color: var(
                --color-background-opaque-hover-active-narrow-filter
            );
        }
    }

    .sidebar-topic-check {
        background-color: var(--color-background-active-narrow-filter);
    }

    .sidebar-topic-name-inner {
        color: var(--color-text-active-narrow-filter);
    }
}

#stream_filters .narrow-filter.active-filter {
    .topic-list .filter-topics,
    > .bottom_left_row {
        background-color: var(--color-background-active-narrow-filter);
        border-radius: 4px;

        &:hover {
            background-color: var(--color-background-hover-narrow-filter);
        }
    }
}

#left-sidebar-navigation-list-condensed {
    display: flex;
    justify-content: center;

    .left-sidebar-navigation-condensed-item {
        /* 24px minimum width from Vlad's design. */
        flex: 1 0 24px;
        /* Unset padding from individual top_left items */
        padding: 0;
        border-radius: 4px;
        /* Set a positioning context for the unread dot. */
        position: relative;

        .unread_count {
            position: absolute;
        }

        /* Show the same styles when each item is
           hovered or, via the keyboard, the `<a>`
           element within receives focus. */
        &:hover,
        &:focus-within {
            background: var(--color-background-navigation-item-hover);

            .unread_count {
                /* 6px at 12px/1em */
                top: -0.5em;
                right: -0.5em;
                background: var(--color-background-unread-counter-no-alpha);
            }
        }

        &:not(:hover) .unread_count {
            top: 2px;
            right: 2px;
            width: 6px;
            height: 6px;
            font-size: 0;
            padding: 0;
            background-color: var(--color-background-unread-counter-dot);
        }

        &.top_left_starred_messages .unread_count {
            display: none;
        }
    }

    .left-sidebar-navigation-icon-container {
        /* Unset margin from full nav list anchor elements. */
        margin: 0;
        /* Horizontally center icons within their boxes. */
        text-align: center;

        &:focus {
            /* Unset inherited :focus outline. */
            outline: 0;
        }
    }

    .active-filter {
        /* Don't display a background on condensed icons. */
        background: unset;
    }

    .filter-icon {
        display: flex;
        align-items: center;
        justify-content: center;
        /* TODO: Set this 24px height value as a variable.
           Keep filter-icon height the full height of the box. */
        height: 24px;
        /* Enlarge icons slightly in condensed views. */
        font-size: 15px;
        color: var(--color-left-sidebar-navigation-icon);
    }
}

#left-sidebar-navigation-list {
    margin-bottom: var(--left-sidebar-sections-vertical-gutter);
    /* We display this as a grid only to control
       the order of home views, using a single
       named grid area. */
    display: grid;
    grid-template-areas: "selected-home-view";
    line-height: var(--line-height-sidebar-row);
    /* Explicitly ensure parity with the line-height
       for the sake of low-resolution screens, whose
       font-rendering and rounding may cause icons
       to appear out of alignment. This grid feature should
       only apply in the expanded-navigation view. */
    grid-auto-rows: var(--line-height-sidebar-row);

    .left-sidebar-navigation-label-container {
        .left-sidebar-navigation-label {
            /* Again, for the sake of low-resolution screens,
               we'll let the actual label take 1 as a line-height
               value, and allow grid to handle the alignment. */
            line-height: 1;
            overflow: hidden;
            text-overflow: ellipsis;
            white-space: nowrap;
        }
    }
}

.selected-home-view {
    /* This bumps the selected view to the
       top of the grid (expanded list).
       Others items will auto place in the
       remaining auto-generated grid rows. */
    grid-area: selected-home-view;
    /* The condensed view is a flexbox, so
       here we'll use a negative order to
       bump the selected home view to the
       start of the flexbox (lefthand side). */
    order: -1;
}

.top_left_starred_messages .unread_count,
.top_left_drafts .unread_count,
.top_left_scheduled_messages .unread_count,
.condensed-views-popover-menu .unread_count {
    background-color: unset;
    color: inherit;
    border: 0.5px solid var(--color-border-unread-counter);
}

/* Don't show unread counts on views... */
.top_left_my_reactions,
.top_left_inbox,
.top_left_recent_view,
.top_left_all_messages {
    .unread_count {
        visibility: hidden;
    }
    /* ...unless it's the selected home view. */
    &.selected-home-view .unread_count {
        visibility: visible;
    }
}

/* Don't show the scheduled messages item... */
li.top_left_scheduled_messages {
    display: none;
    /* ...unless there are scheduled messages to show. */
    &.show-with-scheduled-messages {
        /* Use display: grid to preserve the grid
           layout when visible. */
        display: grid;
    }
}

.left-sidebar-navigation-label-container {
    grid-area: row-content;
    /* The label container itself is also a grid,
       for laying out the items that are its
       children. Same template areas, different
       column widths. */
    grid-template-columns:
        var(--left-sidebar-toggle-width-offset) var(
            --left-sidebar-icon-column-width
        )
        var(--left-sidebar-icon-content-gap) minmax(0, 1fr) max-content 0 0;

    .filter-icon {
        grid-area: starting-anchor-element;
        /* Use a flex container to handle
           icon centering within the grid area. */
        display: flex;
        justify-content: center;
    }

    .left-sidebar-navigation-label {
        grid-area: row-content;
        padding-right: var(--left-sidebar-before-unread-count-padding);
    }

    .unread_count {
        grid-area: markers-and-controls;
    }
}

.top_left_starred_messages {
    &.hide_starred_message_count {
        .masked_unread_count {
            display: block;
            grid-area: markers-and-controls;
            /* Adding margin-right aligns the .masked_unread_count with the rest of the masked unread counts in the channel list. */
            margin-right: var(--masked-unread-count-margin-right);
        }

        .unread_count {
            display: none;
        }
        /* When starred message count is 0, we dont want to show unread_count or masked_unread_count. */
        .unread_count.hide + .masked_unread_count {
            display: none;
        }
    }
}

.top_left_starred_messages:hover {
    &.hide_starred_message_count {
        .masked_unread_count {
            display: none;
        }

        .unread_count {
            display: inline;
        }

        .unread_count.hide {
            display: none;
        }
    }
}

.top_left_starred_messages.active-filter {
    &.hide_starred_message_count {
        .masked_unread_count {
            display: none;
        }

        .unread_count {
            display: inline;
        }

        .unread_count.hide {
            display: none;
        }
    }
}

.conversation-partners {
    grid-area: row-content;
    overflow: hidden;
    text-overflow: ellipsis;
    /* Use an inline grid to provide a modern layout
       for status emoji in DM rows, while preserving
       the expected ellipsis behavior on long usernames
       or large DM groups.
       The 16px-tall emoji will also align well
       vertically with the 18px line-height here. */
    display: inline-grid;
    /* Provide a two-column grid, sized to accommodate
       the content of the conversation list and status
       emoji, if any. */
    grid-template-columns: repeat(2, minmax(0, max-content));
    align-items: center;
}

.conversation-partners .status-emoji {
    /* Prevent status emoji from colliding
       with unread counts. */
    margin-right: 3px;
}

/* New .topic-box grid definitions here. */
#views-label-container,
.zoom-in #hide-more-direct-messages,
.top_left_row,
.left-sidebar-navigation-label-container,
.dm-box,
.subscription_block,
.topic-box,
.searching-for-more-topics,
.topic_search_section {
    display: grid;
    align-items: center;
    /* This general pattern of elements applies to every single row in the left
       sidebar, to some degree or another. Eventually, these template areas
       could be applied to all rows, with different `grid-template-column`
       values applied as needed (and shared as needed). For example, an element
       with no "starting-offset" sets that area to `0`; so too with other non-
       existent elements.

       The offsets themselves are meant to greedily assign all of the available
       horizontal space to the content area of the row. That space can then be
       modified or reassigned as needed, without running up against `padding`
       (which alters the box size) or `margin` (which notoriously bleeds outside
       of the element it's defined on). */
    grid-template-areas: "starting-offset starting-anchor-element icon-content-gap row-content markers-and-controls ending-anchor-element ending-offset";
}

.top_left_row {
    /* We stretch the items on the overall
       nav row, so there's no unclickable
       gaps between nav rows. */
    align-items: stretch;
    /* The row grid for the outer .top_left_row
       is chiefly for lefthand spacing and placing
       the inner row content and vdots. */
    grid-template-columns: 0 0 0 minmax(0, 1fr) 0 30px 0;

    .sidebar-menu-icon {
        grid-area: ending-anchor-element;
    }
}

#direct-messages-section-header,
#streams_header,
#topics_header {
    display: grid;
    align-items: center;
    /* This extends the general pattern of left sidebar rows, but includes a
       second grid row for placing filter boxes. This pattern keeps the box
       aligned with the text content in `row-content` and includes the
       `ending-anchor-element` space.

       There is currently no filter box on DM rows, but we can prepare for
       that now by having it share this grid template. Its row and column
       definitions have the final say about dimensions and placement. */
    grid-template-areas:
        "starting-offset starting-anchor-element icon-content-gap row-content markers-and-controls ending-anchor-element ending-offset"
        ".               .                       filter-box       filter-box  filter-box           filter-box            .            ";
}

#views-label-container {
    margin-right: var(--left-sidebar-right-margin);
    grid-template-columns:
        0 var(--left-sidebar-header-icon-toggle-width) 0 minmax(0, 0.5fr) minmax(
            0,
            1fr
        )
        30px 0;
    grid-template-rows: 28px;
    cursor: pointer;
    border-radius: 4px;

    &:not(.remove-pointer-for-spectator):hover {
        background-color: var(--color-background-hover-narrow-filter);
        box-shadow: inset 0 0 0 1px var(--color-shadow-sidebar-row-hover);

        .left-sidebar-title,
        .sidebar-heading-icon {
            opacity: var(--opacity-sidebar-heading-hover);
        }
    }

    &.showing-expanded-navigation {
        /* When the expanded navigation is visible,
           hide the condensed navigation's controls. */
        #left-sidebar-navigation-list-condensed,
        .left-sidebar-navigation-menu-icon {
            display: none;
        }
        /* Give the sidebar title through the end of the markers
           area, if needed. */
        .left-sidebar-title {
            grid-column: row-content-start / markers-and-controls-end;
        }
    }

    /* Use a next-sibling combinator (+) to use CSS to show and hide
       filter rows as needed, based on the narrow. */
    &.showing-condensed-navigation {
        + #left-sidebar-navigation-list {
            /* In the condensed state, we don't want to generate
               auto rows, or there will be a footprint where the
               expanded nav sits. */
            grid-auto-rows: unset;
            /* When the navigation area is condensed, hide all
               the rows in the full navigation list... */
            & .top_left_row {
                display: none;
            }
            /* ...except when there is an active filter in place:
               that row should still be shown. */
            & .top_left_row.active-filter {
                display: grid;
                /* In the absence of auto rows in the condensed state,
                   we set an explicit height on the active filter. */
                height: var(--line-height-sidebar-row);
            }
        }
    }

    /* Remove the cursor: pointer property of Views label for the spectators. */
    &.remove-pointer-for-spectator {
        cursor: default;
    }

    #toggle-top-left-navigation-area-icon {
        grid-area: starting-anchor-element;
        /* Horizontally center the icon in its allotted grid area. */
        justify-self: center;
    }

    .left-sidebar-title {
        grid-area: row-content;
    }

    #left-sidebar-navigation-list-condensed {
        margin: 0;
        grid-area: markers-and-controls;
    }

    .left-sidebar-navigation-menu-icon {
        grid-area: ending-anchor-element;
        /* Horizontally center vdots. */
        justify-self: stretch;
        /* Properly size vdots. */
        font-size: 17px;
        /* Occupy same clickable height as
           other condensed-view icons */
        height: 24px;
        /* Vertically center dots with
           flexbox. */
        display: flex;
        align-items: center;
        justify-content: center;
        margin-right: 2px;
        border-radius: 3px;
        color: var(--color-vdots-visible);

        &:hover {
            color: var(--color-vdots-hover);
            background-color: var(--color-background-sidebar-action-hover);
        }
    }
}

.condensed-views-popover-menu {
    .unread_count {
        margin: 1px 0 0 6px;
        border-color: var(--color-border-unread-counter-popover-menu);
        width: max-content;
    }
}

.subscription_block {
    grid-template-columns:
        var(--left-sidebar-toggle-width-offset) var(
            --left-sidebar-icon-column-width
        )
        var(--left-sidebar-icon-content-gap) minmax(0, 1fr) minmax(
            0,
            max-content
        )
        30px 0;
    white-space: nowrap;

    .stream-privacy {
        grid-area: starting-anchor-element;
        display: flex;
        place-content: center center;

        .zulip-icon.zulip-icon-globe {
            /* 12px at 14px/1em */
            font-size: 0.8571em;
        }

        .zulip-icon.zulip-icon-hashtag {
            /* 13px at 14px/1em */
            font-size: 0.9286em;
        }

        .zulip-icon.zulip-icon-lock {
            /* 13px at 14px/1em */
            font-size: 0.9286em;
        }
    }

    .stream-name {
        grid-area: row-content;
    }
}

.topic-box,
.searching-for-more-topics {
    grid-template-columns:
        0 var(--left-sidebar-icon-column-width) var(
            --left-sidebar-icon-content-gap
        )
        minmax(0, 1fr) minmax(0, max-content)
        30px 0;
}

.searching-for-more-topics {
    margin-left: var(--left-sidebar-toggle-width-offset);
    height: var(--line-height-sidebar-row-prominent);
}

.topic_search_section {
    grid-template-columns:
        var(--left-sidebar-toggle-width-offset) 0 0 minmax(0, 1fr) minmax(
            0,
            max-content
        )
        30px 0;
}

.topic-box .zero_count {
    display: none;
}

.sidebar-topic-name,
.sidebar-topic-action-heading {
    cursor: pointer;
    grid-area: row-content;
    padding: 0 var(--left-sidebar-before-unread-count-padding) 0 0;
    /* TODO: Consolidate these styles with conversation partners and stream name
        once grid rewrite is complete on all sidebar rows.

        Also: note that these styles will be moot for topic names once we allow
        for multiline topics. If we hold multiline topics to a certain number
        of lines, we'll likely need a JavaScript-based solution like Clamp.js
        to display an ellipsis on the final visible line. */
    white-space: nowrap;
    /* Both `hidden` and `clip` are shown for the sake
        of older browsers that do not support `clip`. */
    overflow-x: hidden;
    overflow-x: clip;
    text-overflow: ellipsis;

    span.sidebar-topic-name-inner {
        white-space: pre;
    }

    &:hover {
        color: inherit;
    }

    &:focus {
        text-decoration: none;
    }
}

.sidebar-topic-action-heading {
    color: var(--color-text-sidebar-action-heading);
    font-size: var(--font-size-sidebar-action-heading);
    font-weight: var(--font-weight-sidebar-action-heading);
    font-variant: var(--font-variant-sidebar-action-heading);
    font-feature-settings: var(--font-feature-settings-sidebar-action-heading);
    text-transform: var(--text-transform-sidebar-action-heading);

    &:hover {
        text-decoration: none;
        /* Push back against a:hover color in dark_theme.css. */
        color: var(--color-text-sidebar-action-heading-hover) !important;
    }
}

.topic-list-filter {
    grid-area: row-content;
}

#filter-topic-input:placeholder-shown + #clear_search_topic_button {
    display: none;
}

.searching-for-more-topics img {
    height: 16px;
    grid-area: row-content;
}

.sidebar-topic-check {
    grid-area: starting-anchor-element;
    justify-self: end;
    /* 15px at 14px/1em */
    font-size: 1.0714em;
    /* Use background to mask part of grouping bracket. */
    padding-left: 3px;
    /* Keep background from affecting rounded corners on
       .active-sub-filter by reducing the checkbox
       line-height to match its font size. */
    line-height: 1;
    /* As a grid item, adjust the checkmark's z-index here so
       that the background color appears above the grouping
       bracket's bottom line. Its value must less than
       the z-index set on the #streams_header selector. */
    z-index: 1;
}

.stream-markers-and-controls,
.topic-markers-and-controls {
    grid-area: markers-and-controls;
    display: flex;
    /* Present a uniform space between icons */
    gap: 5px;
    align-items: center;

    .unread_mention_info {
        /* Unset margin in favor of flex gap. */
        margin: 0;
    }

    .unread_count {
        /* Height is set here by the flexbox; this
           decouples .unread_count from the app-wide
           definition. */
        height: auto;
    }
}

.bottom_left_row .sidebar-menu-icon {
    grid-area: ending-anchor-element;
}

.conversation-partners-list,
.stream-name {
    white-space: nowrap;
    overflow-x: hidden;
    overflow-x: clip;
    text-overflow: ellipsis;
    padding: 0 var(--left-sidebar-before-unread-count-padding) 0 0;
}

/*
    All of our left sidebar handlers use absolute
    positioning.  We should fix that.
*/
.bottom_left_row .sidebar-menu-icon,
.top_left_row .sidebar-menu-icon {
    display: none;
    cursor: pointer;
    /* Use a flex container to handle
       icon centering within the grid area.
       :hover actually sets the `display: flex`,
       so it remains hidden otherwise. */
    justify-content: center;
    align-items: center;
    text-align: center;
    /* Ensure icons are vertically aligned, in
       case they appear in a grid definition,
       like the nav rows, that use a different
       centering regime for the row. */
    align-self: stretch;
    border-radius: 3px;
    margin: 2px 2px 2px 1px;
    /* This helps horizontally align the vdots,
       given the reduced margin-left above. */
    padding-left: 1px;
    /* Set the icon size, which will be inherited
       by .zulip-icon */
    font-size: 17px;

    /*
        If you hover directly over the ellipsis itself,
        show it in black.
    */

    &:hover {
        color: var(--color-vdots-hover);
    }

    /*
        Hover does not work for touch-based devices like mobile phones.
        Hence the icons does not appear, making the user unaware of its
        presence on such devices. The following media property displays the
        icon by default for such behaviour.
    */

    @media (hover: none) {
        display: flex;
        /* Show dots on touchscreens in a less distracting,
           lighter shade. */
        color: var(--color-vdots-hint);
    }
}

/*
    When you hover over list items, we hover
    the vdots in light gray.

    The stream icon should always display when
    any topic is hovered, which is why it gets
    a more specific selector here.
*/
#stream_filters li:hover .stream-sidebar-menu-icon,
.top_left_row:hover .sidebar-menu-icon,
.bottom_left_row:hover .sidebar-menu-icon,
.app-main .column-left .left-sidebar .left_sidebar_menu_icon_visible {
    /* We push against `display: none` with
       `display: flex` because the sidebar vdots
       all expect to be displayed as flex items
       when visible. Their vertical alignment
       depends on it, too. */
    display: flex;
    color: var(--color-vdots-visible);

    &:hover {
        color: var(--color-vdots-hover);
        background-color: var(--color-background-sidebar-action-hover);
    }
}

/*
    For topic ellipsis-v(vertical 3 dots) we use a slightly smaller
    font to show they're "lower" in the hierarchy,
    which also affects it positioning.
*/
.topic-sidebar-menu-icon {
    /* 0.9em, but with a pixel value because the
       ordinary 17px vdots size is not inherited
       here, so we can't express an em-value
       directly. Pixels are easier to reason
       about with icons, anyway. */
    font-size: 15.3px;
}

ul.topic-list {
    line-height: var(--line-height-sidebar-row-prominent);
    list-style-type: none;
    font-weight: normal;
}

ul.topic-list.topic-list-has-topics::before {
    content: " ";
    display: block;
    position: absolute;
    /* 12px at 16px/1em */
    top: 0.75em;
    bottom: 0.75em;
    left: 9px;
    border: 1px solid var(--color-topic-indent-border);
    border-right: 0;
    border-radius: 9px 0 0 9px;
    width: 6px;
    pointer-events: none;
}

ul.topic-list.topic-list-has-topics::after {
    content: " ";
    display: block;
    position: absolute;
    /* -14px at 16px/1em */
    top: -0.875em;
    /* 12px at 16px/1em */
    bottom: 0.75em;
    left: 16px;
    width: 12px;
    border-bottom: 1px solid var(--color-topic-indent-border);
    pointer-events: none;
}

ul.topic-list:has(.show-more-topics)::after {
    /* When the show all topics control is displayed,
       extend the bottom bracket. */
    width: 18px;
}

/* The grouping border should not be shown
   on zoomed-in views. */
.zoom-in .topic-list.topic-list-has-topics::before,
.zoom-in .topic-list.topic-list-has-topics::after {
    border: 0;
}

li.topic-list-item {
    position: relative;
    padding-right: 5px;
    margin-left: var(--left-sidebar-toggle-width-offset);
}

.dm-box {
    grid-template-columns:
        var(--left-sidebar-toggle-width-offset) [action-heading-start] var(
            --left-sidebar-icon-column-width
        )
        var(--left-sidebar-icon-content-gap) minmax(0, 1fr) [action-heading-end] minmax(
            0,
            max-content
        )
        30px 0;
    grid-template-rows: [action-heading-start] auto [action-heading-end];

    .conversation-partners-icon {
        grid-area: starting-anchor-element;
        place-self: center;
    }

    .dm-name {
        grid-area: action-heading;
    }

    .user_circle {
        width: var(--length-user-status-circle);
        height: var(--length-user-status-circle);

        @media screen and (resolution <= 1x) {
            /* User circles appear to sag a bit on
               low-resolution screens, so this fix
               targets them without disrupting
               line-height values that may become
               important in multi-line DM groups, etc.
               in the future. */
            margin-top: -2.5px;
        }
    }

    .unread_count {
        grid-area: markers-and-controls;
        /* TODO: This is an alternative method
           for presenting a 16px-tall unread
           counter, regardless of context. This
           method could be used app-wide once
           all of the layout methods for presenting
           unreads have been modernized.

           Set the line-height to match the
           font-size, so that the numerals sit in
           a 12px box. */
        line-height: 12px;
        /* Use flexbox to vertically center
           the 12px-high text node within the
           16px-high unread box. */
        display: flex;
        align-items: center;
    }
}

/* Since direct-messages-sticky-header also has the `input-append`
   class accompanying it. The display property of that class will
   overwrite display: none if we don't have a more specific CSS
   rule. It will also overwrite `display: none` even if `.zoom-out`
   properties are declared after the `.input-append` properties since
   the latter is more specific. */
#direct-messages-sticky-header.zoom-out,
.zoom-out {
    #topics_header {
        display: none;
    }

    .zoom-out-hide {
        display: none;
    }
}

#topics_header {
    position: sticky;
    top: 0;
    z-index: 2;
    grid-template-columns:
        [topics-content-area-start] var(--left-sidebar-toggle-width-offset)
        0 0 minmax(0, 1fr)
        max-content 0 42px [topics-content-area-end];
    grid-template-rows:
        [topics-content-area-start] var(--line-height-sidebar-row-prominent)
        [topics-content-area-end];
    padding-top: var(--left-sidebar-sections-vertical-gutter);
    color: hsl(0deg 0% 43%);
    background-color: var(--color-background);

    .show-all-streams {
        grid-area: topics-content-area;
        padding-left: var(--left-sidebar-toggle-width-offset);
        font-size: var(--font-size-sidebar-action-heading);
        font-weight: var(--font-weight-sidebar-action-heading);
        font-variant: var(--font-variant-sidebar-action-heading);
        text-transform: var(--text-transform-sidebar-action-heading);
        color: var(--color-text-sidebar-action-heading);
        text-decoration: none;

        &:hover {
            background-color: var(
                --color-background-sidebar-action-heading-hover
            );
            box-shadow: inset 0 0 0 1px var(--color-shadow-sidebar-row-hover);
            border-radius: 4px;
        }
    }

    .unread_count {
        grid-area: markers-and-controls;
    }
}

#streams_header {
    grid-template-columns:
        var(--left-sidebar-toggle-width-offset) 0 0 minmax(0, 1fr)
        minmax(17px, max-content) 30px 0;
    /* Keep the stream-search area rows collapsed. */
    grid-template-rows: var(--line-height-sidebar-row-prominent) 0 0;
    cursor: pointer;
    margin: var(--left-sidebar-sections-vertical-gutter)
        var(--left-sidebar-right-margin) 3px 0;
    position: sticky;
    /* Keep sticky within SimpleBar context. */
    top: 0;
    z-index: 2;
    background-color: var(--color-background);
    border-radius: 4px;

    &:hover {
        background-color: var(--color-background-opaque-hover-narrow-filter);
        box-shadow: inset 0 0 0 1px var(--color-shadow-sidebar-row-hover);

        .left-sidebar-title,
        .sidebar-heading-icon {
            opacity: var(--opacity-sidebar-heading-hover);
        }
    }

    &.showing-stream-search-section {
        /* Open up the stream-search rows. The 10px
           row maintains space with the streams list
           below. */
        grid-template-rows: var(--line-height-sidebar-row-prominent) 28px 10px;

        /* When the search section is showing, switch
           off the hover effects on the row. */
        &:hover {
            background-color: var(--color-background);
            box-shadow: unset;
        }
    }

    .left-sidebar-title {
        grid-area: row-content;
    }

    .heading-markers-and-controls {
        grid-area: markers-and-controls;
        height: 100%;
        display: flex;
        align-items: center;
        grid-gap: 5px;
    }

    #filter_streams_tooltip {
        display: flex;
        align-items: center;
        justify-content: center;
        width: var(--left-sidebar-header-icon-width);
    }

    #add_streams_tooltip {
        display: flex;
        align-items: center;
        justify-content: center;
        width: var(--left-sidebar-header-icon-width);
    }

    .stream_search_section {
        grid-area: filter-box;
        display: flex;
        justify-content: stretch;
        /* Set an even line-height for better
           vertical centering. */
        line-height: 20px;
        white-space: nowrap;
    }

    &.hide_unread_counts {
        .unread_count,
        .unread_count.hide,
        .masked_unread_count {
            display: none;
        }

        /* When an empty unread count is hidden,
           hide the masked unread count, too. */
        .unread_count.hide + .masked_unread_count {
            display: none;
        }

        .masked_unread_count {
            display: block;
            /* Hold space enough so single-digit
               unreads don't shift on hover. */
            margin: 0 3px;
        }

        &:hover {
            .unread_count {
                display: block;
            }

            .hide,
            .masked_unread_count {
                display: none;
            }
        }
    }
}

.stream_search_section,
.direct-messages-search-section {
    .stream-list-filter,
    .direct-messages-list-filter {
        /* Use the border-box model so flex
           can do its thing despite whatever
           padding and border we specify. */
        box-sizing: border-box;
        flex: 1 0 100%;
        /* Match the input height exactly
           with the row height for a perfect
           fit and better vertical alignment. */
        height: 28px;
        /* Pad the entire clear-button area,
           so that input text does not bleed
           into there. */
        padding-right: 30px;
    }

    .clear_search_button {
        /* Use the border-box model so flex
           can do its thing despite whatever
           padding and border we specify. */
        box-sizing: border-box;
        /* Clear inherited positioning. */
        position: static;
        /* We're going to use flexbox, not
           positioning, to get the clear button
           over top of the input. This -30px
           margin accomplishes that, in tandem
           with the 30px width of this element,
           which is shared with the ending
           anchor element in left sidebar header
           rows. */
        width: 30px;
        margin-left: -30px;
        /* Flexbox respects z-index; this just
           ensures the button remains over top
           of the input. */
        z-index: 1;
        /* Make the button itself a flex container,
           so we can perfectly center the X icon. */
        display: flex;
        justify-content: center;
        align-items: center;
        /* Flexbox will pull the element open
           to make a generous clickable area. */
        padding: 0;
    }

    .direct-messages-list-filter:placeholder-shown
        + #clear-direct-messages-search-button {
        display: none;
    }
}

/* Prepare an adjusted grid for the logged-out state,
   one that reassigns the vdots space to markers and
   controls. */
.spectator-view #streams_header {
    grid-template-columns:
        var(--left-sidebar-toggle-width-offset) 0 0 minmax(0, 1fr)
        minmax(30px, max-content) 0 0;
    margin-right: var(--left-sidebar-right-margin);

    /* With markers and controls now sized the same
       as the ordinary vdots area (but allowed to grow,
       care of `minmax(30px, max-content)`, should
       additional logged-out icons be added in the
       future), let's center the icon in that area,
       just like vdots would be. */
    .heading-markers-and-controls {
        justify-content: center;
    }
}

.streams_subheader {
    /* 14px at 16px/1em */
    font-size: 0.875em;
    font-weight: normal;
    /* 16px line-height at 0.8em (11.2px at 14px legacy em) */
    line-height: 1.4286em;
    letter-spacing: 0.04em;
    padding-left: var(--left-sidebar-toggle-width-offset);
    cursor: pointer;
    text-align: center;
    margin-right: var(--left-sidebar-right-margin);

    & .streams-subheader-wrapper {
        display: flex;
        flex-direction: row;
        width: 100%;
        left: 0.5em;
        right: 0.5em;
        color: var(--color-text-sidebar-base);
    }

    & .streams-subheader-wrapper::before,
    .streams-subheader-wrapper::after {
        content: " ";
        flex: 1 1;
        vertical-align: middle;
        margin: auto;
        border-top: 1px solid var(--color-border-sidebar-subheader);
    }

    & .streams-subheader-wrapper::before {
        margin-right: 0.2em;
    }

    & .streams-subheader-wrapper::after {
        margin-left: 0.2em;
    }

    .streams-subheader-name {
        opacity: 0.4;
    }
}

.stream-list-filter {
    white-space: nowrap;
    text-overflow: ellipsis;
    overflow: hidden;
}

.zero_count {
    visibility: hidden;
}

.zero-topic-unreads.show-more-topics .topic-box {
    margin-right: 30px;
}

.zoom-in {
    .narrow-filter > .bottom_left_row {
        position: sticky;
        top: calc(
            var(--left-sidebar-sections-vertical-gutter) +
                var(--line-height-sidebar-row-prominent)
        );
        z-index: 2;
        padding-bottom: 1px;
        background-color: var(--color-background);

        &:hover {
            /* Prevent hover styles set on other rows. */
            box-shadow: none;
            background-color: var(--color-background);
        }
    }

    #streams_header,
    #subscribe-to-more-streams,
    .show-more-topics {
        display: none;
    }

    &.direct-messages-container ul.dm-list {
        margin-bottom: var(--left-sidebar-bottom-scrolling-buffer);
    }

    #hide-more-direct-messages {
        grid-template-columns: inherit;
        grid-column: 1 / -1;
        line-height: var(--line-height-sidebar-row);
        text-decoration: none;
        color: inherit;

        .hide-more-direct-messages-text {
            color: var(--color-text-sidebar-action-heading);
            font-size: var(--font-size-sidebar-action-heading);
            font-weight: var(--font-weight-sidebar-action-heading);
            font-variant: var(--font-variant-sidebar-action-heading);
            text-transform: var(--text-transform-sidebar-action-heading);
            grid-area: row-content;
        }

        &:hover {
            background-color: var(
                --color-background-sidebar-action-heading-hover
            );
            box-shadow: inset 0 0 0 1px var(--color-shadow-sidebar-row-hover);
            border-radius: 4px;
        }
    }

    .direct-messages-search-section {
        display: flex;
        grid-column: row-content / markers-and-controls;
        margin-top: 5px;
        margin-bottom: 5px;
    }

    .zoom-in-hide {
        display: none;
    }

    .zoom-in-sticky {
        position: sticky;
        top: 0;
        z-index: 1;
    }
}