element-web/res/css/structures/_UserMenuButton.scss

/*
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_UserMenuButton {
    // No special styles on the button itself
}

.mx_UserMenuButton_contextMenu {
    width: 231px;

    .mx_UserMenuButton_contextMenu_header {
        // Create a flexbox to organize the header a bit easier
        display: flex;
        align-items: center;

        &:nth-child(n + 1) {
            // The first header will have appropriate padding, subsequent ones need a margin.
            margin-top: 10px;
        }

        .mx_UserMenuButton_contextMenu_name {
            // Create another flexbox of columns to handle large user IDs
            display: flex;
            flex-direction: column;

            // fit the container
            flex: 1;
            width: calc(100% - 40px); // 40px = 32px theme button + 8px margin to theme button

            * {
                // Automatically grow all subelements to fit the container
                flex: 1;
                width: 100%;

                // Ellipsize any text overflow
                text-overflow: ellipsis;
                overflow: hidden;
                white-space: nowrap;
            }

            .mx_UserMenuButton_contextMenu_displayName {
                font-weight: bold;
                font-size: $font-15px;
                line-height: $font-20px;
            }

            .mx_UserMenuButton_contextMenu_userId {
                font-size: $font-15px;
                line-height: $font-24px;
            }
        }

        .mx_UserMenuButton_contextMenu_themeButton {
            min-width: 32px;
            max-width: 32px;
            width: 32px;
            height: 32px;
            margin-left: 8px;
            border-radius: 32px;
            background-color: $theme-button-bg-color;
            cursor: pointer;

            // to make alignment easier, create flexbox for the image
            display: flex;
            align-items: center;
            justify-content: center;
        }
    }
}