element-web/res/css/views/rooms/_RoomBreadcrumbs2.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.
*/

@keyframes breadcrumb-popin {
    0% {
        // Ideally we'd use `width` instead of `opacity`, but we only
        // have 16 nanoseconds to render the frame, and width is expensive.
        opacity: 0;
        transform: scale(0);
    }
    100% {
        opacity: 1;
        transform: scale(1);
    }
}

.mx_RoomBreadcrumbs2 {
    // Create a flexbox for the crumbs
    display: flex;
    flex-direction: row;
    align-items: flex-start;
    width: 100%;

    .mx_RoomBreadcrumbs2_crumb {
        margin-right: 8px;
        width: 32px;

        // React loves to add elements, so only target the one we want to animate
        &:first-child {
            animation: breadcrumb-popin 0.3s;
        }
    }

    .mx_RoomBreadcrumbs2_placeholder {
        font-weight: 600;
        font-size: $font-14px;
        line-height: 32px; // specifically to match the height this is not scaled
        height: 32px;
    }
}