Source/WebCore/Modules/modern-media-controls/controls/activity-indicator.css

/*
 * Copyright (C) 2017 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.
 */

.activity-indicator {
    position: absolute;
    mix-blend-mode: plus-lighter;
}

.activity-indicator > div {
    position: absolute;
    left: 6px;
    width: 2px;
    height: 4px;
    border-radius: 1px;
    background-color: white;
    animation-name: activity-indicator-pulse;
    animation-duration: 1s;
    animation-timing-function: linear;
    animation-iteration-count: infinite;
    transform-origin: 50% 7px;
}

.activity-indicator > .ne {
    transform: rotate(45deg);
    animation-delay: -875ms;
}

.activity-indicator > .e {
    transform: rotate(90deg);
    animation-delay: -750ms;
}

.activity-indicator > .se {
    transform: rotate(135deg);
    animation-delay: -625ms;
}

.activity-indicator > .s {
    transform: rotate(180deg);
    animation-delay: -500ms;
}

.activity-indicator > .sw {
    transform: rotate(-135deg);
    animation-delay: -375ms;
}

.activity-indicator > .w {
    transform: rotate(-90deg);
    animation-delay: -250ms;
}

.activity-indicator > .nw {
    transform: rotate(-45deg);
    animation-delay: -125ms;
}

@keyframes activity-indicator-pulse {
    from { opacity: 0.9  }
    to   { opacity: 0.25 }
}