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

/*
Copyright 2015, 2016 OpenMarket Ltd

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_MatrixChat_splash {
    position: relative;
    height: 100%;
}

.mx_MatrixChat_splashButtons {
    text-align: center;
    width: 100%;
    position: absolute;
    bottom: 30px;
}

.mx_MatrixChat_wrapper {
    display: flex;

    width: 100%;
    height: 100%;
}

.mx_MatrixToolbar {
    order: 1;

    height: 40px;
}

.mx_MatrixChat {
    position: relative;
    width: 100%;
    height: 100%;

    display: flex;

    flex: 1;
    min-height: 0;
}

.mx_MatrixChat_syncError {
    color: $accent-fg-color;
    background-color: #DF2A8B; // Only used here
    border-radius: 5px;
    display: table;
    padding: 30px;
    position: absolute;
    top: 100px;
    left: 50%;
    transform: translateX(-50%);
}

/* not the left panel, and not the resize handle, so the roomview/groupview/... */
.mx_MatrixChat > :not(.mx_LeftPanel):not(.mx_SpacePanel):not(.mx_ResizeHandle):not(.mx_LeftPanel_wrapper) {
    background-color: $background;

    flex: 1 1 0;
    min-width: 0;

    /* To fix https://github.com/vector-im/element-web/issues/3298 where Safari
       needed height 100% all the way down to the HomePage. Height does not
       have to be auto, empirically.
    */
    height: 100%;
}

// We'd like to remove this, but this makes matrixchat's resizehandle's
// negative margin greater than its positive padding. If it's the same
// or less, Safari and other WebKit based browsers get confused about overflows somehow and
// https://github.com/vector-im/element-web/issues/19863 happens.
.mx_MatrixChat > .mx_ResizeHandle.mx_ResizeHandle_horizontal {
    margin: 0 calc(-5.5px - $container-gap-width / 2) 0 calc(-6.5px + $container-gap-width / 2);
    // The condition to prevent bleeding is: (margin-left + margin-right < -11px) (IF there is NO margin on the leftPanel_wrapper)
    // The resizeHandle does not change the gap between the left panel and the room view:
    //  the resizeHandle width is: 11px =  10px (padding) + 1px (width) and the total negative margin is -12px -> the handle requires no space
    // right: -6px left: -6px positions the element exactly on the edge of leftPanel.
    // left+=1 and right-=1 => resizeHandle moves 1px to the right closer to the center of the gap.
    // We want the handle to be in the middle of the gap so it is shifted by ($container-gap-width / 2)
}

.mx_MatrixChat > .mx_ResizeHandle_horizontal:hover {
    position: relative;

    &::before {
        position: absolute;
        top: 50%;
        left: 50%;
        transform: translate(-50%, -50%);

        height: 64px; // to match width of the ones on roomlist
        width: 4px;
        border-radius: 4px;

        content: ' ';

        background-color: $primary-content;
        opacity: 0.8;
    }
}