riot-web/res/css/structures/_RightPanel.scss

/*
Copyright 2015, 2016 OpenMarket Ltd
Copyright 2020 The Matrix.org Foundation C.I.C.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

.mx_RightPanel {
    overflow-x: hidden;
    flex: 0 0 auto;
    position: relative;
    min-width: 264px;
    max-width: 50%;
    display: flex;
    flex-direction: column;
    border-radius: 8px;
    margin: 5px;
    padding: 4px 0;

    .mx_RoomView_MessageList {
        padding: 14px 18px; // top and bottom is 4px smaller to balance with the padding set above
    }
}

.mx_RightPanel_header {
    order: 1;
    border-bottom: 1px solid $primary-hairline-color;
    flex: 0 0 52px;
}

/** Fixme - factor this out with the main header **/

.mx_RightPanel_headerButtonGroup {
    height: 100%;
    display: flex;
    background-color: $primary-bg-color;
    padding: 0 9px;
    align-items: center;
}

.mx_RightPanel_headerButton {
    cursor: pointer;
    flex: 0 0 auto;
    margin-left: 1px;
    margin-right: 1px;
    height: 32px;
    width: 32px;
    position: relative;
    border-radius: 100%;

    &::before {
        content: '';
        position: absolute;
        top: 6px; // center with parent of 32px
        left: 6px; // center with parent of 32px
        height: 20px;
        width: 20px;
        background-color: $rightpanel-button-color;
        mask-repeat: no-repeat;
        mask-size: contain;
    }
}

.mx_RightPanel_membersButton::before {
    mask-image: url('$(res)/img/element-icons/room/members.svg');
    mask-position: center;
}

.mx_RightPanel_filesButton::before {
    mask-image: url('$(res)/img/element-icons/room/files.svg');
    mask-position: center;
}

.mx_RightPanel_notifsButton::before {
    mask-image: url('$(res)/img/element-icons/notifications.svg');
    mask-position: center;
}

.mx_RightPanel_groupMembersButton::before {
    mask-image: url('$(res)/img/element-icons/community-members.svg');
    mask-position: center;
}

.mx_RightPanel_roomsButton::before {
    mask-image: url('$(res)/img/element-icons/community-rooms.svg');
    mask-position: center;
}

.mx_RightPanel_headerButton_highlight {
    background: rgba($accent-color, 0.25);
    // make the icon the accent color too
    &::before {
        background-color: $accent-color;
    }
}

.mx_RightPanel_headerButton:not(.mx_RightPanel_headerButton_highlight) {
    &:hover {
        background: rgba($accent-color, 0.1);

        &::before {
            background-color: $accent-color;
        }
    }
}

.mx_RightPanel_headerButton_badge {
    font-size: $font-8px;
    border-radius: 8px;
    color: $accent-fg-color;
    background-color: $accent-color;
    font-weight: bold;
    position: absolute;
    top: -4px;
    left: 20px;
    padding: 2px 4px;
}

.mx_RightPanel_collapsebutton {
    flex: 1;
    text-align: right;
    height: 16px;
    border: none;
}

.mx_RightPanel .mx_MemberList,
.mx_RightPanel .mx_MemberInfo,
.mx_RightPanel .mx_GroupRoomList,
.mx_RightPanel_blank {
    order: 2;
    flex: 1 1 0;
}

.mx_RightPanel .mx_RoomView_messagePanelSpinner {
    order: 2;
    margin: auto;
}