element-web/res/css/views/audio_messages/_AudioPlayer.scss

/*
Copyright 2021 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_AudioPlayer_container {
    padding: 16px 12px 12px 12px;
    max-width: 267px; // use max to make the control fit in the files/pinned panels

    .mx_AudioPlayer_primaryContainer {
        display: flex;

        .mx_PlayPauseButton {
            margin-right: 8px;
        }

        .mx_AudioPlayer_mediaInfo {
            flex: 1;
            overflow: hidden; // makes the ellipsis on the file name work

            & > * {
                display: block;
            }

            .mx_AudioPlayer_mediaName {
                color: $primary-fg-color;
                font-size: $font-15px;
                line-height: $font-15px;
                text-overflow: ellipsis;
                white-space: nowrap;
                overflow: hidden;
                padding-bottom: 4px; // mimics the line-height differences in the Figma
            }

            .mx_AudioPlayer_byline {
                font-size: $font-12px;
                line-height: $font-12px;
            }
        }
    }

    .mx_AudioPlayer_seek {
        display: flex;
        align-items: center;

        .mx_SeekBar {
            flex: 1;
        }

        .mx_Clock {
            width: $font-42px; // we're not using a monospace font, so fake it
            min-width: $font-42px; // for flexbox
            padding-left: 4px; // isolate from seek bar
            text-align: right;
        }
    }
}