Source/WebCore/Modules/modern-media-controls/controls/tracks-panel.css

/*
 * Copyright (C) 2016 Apple Inc. All Rights Reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

.tracks-panel {
    position: absolute;
    display: inline-block;
}

.tracks-panel > .scrollable-container {
    border-radius: 8px;
}

.tracks-panel > .scrollable-container {
    position: relative;
    overflow-y: scroll;
}

.tracks-panel * {
    font-size: 14px;
    font-weight: 500;
}

.tracks-panel.fade-out {
    transition-property: opacity;
    transition-duration: 265ms;
    opacity: 0;
}

.tracks-panel section {
    border-top: 2px solid var(--secondary-glyph-color);
    will-change: transform;
}

.tracks-panel section:first-of-type {
    border-top: 0;
}

.tracks-panel section > h3 {
    color: var(--primary-glyph-color);
    mix-blend-mode: plus-lighter;
    padding: 5px 20px 1px 21px;
    margin: 0;
}

.tracks-panel section > ul {
    list-style-type: none;
    margin-top: 0;
    padding: 0;
}

.tracks-panel section > ul > li {
    position: relative;
    padding: 1px 20px 1px 33px;
    color: white;
}

.tracks-panel section > ul > li:focus {
    background-color: rgb(20, 105, 209);
    outline: none;
}

.tracks-panel section > ul > li.selected:before {
    position: absolute;
    top: 3px;
    left: 12px;
    width: 12px;
    display: inline-block;
    content: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 300 300"><polygon fill="white" points="252.301,4.477 126.667,194.104 43.358,108.3 6.868,161.408 132.515,290.814 297.732,49.926"/></svg>');
}

.tracks-panel section > ul > li.animated {
    animation-name: tracks-panel-item-selection;
    animation-duration: 150ms;
    animation-timing-function: step-end;
    animation-fill-mode: forwards;
}

@keyframes tracks-panel-item-selection {
    0%, 55.55% {
        background-color: rgba(26, 68, 243, 0.6);
        -webkit-backdrop-filter: saturate(180%) blur(20px);
    }

    22.22% {
        background: none;
        -webkit-backdrop-filter: none;
    }
}