Source/WebCore/css/fullscreen.css

/*
 * Copyright (C) 2020 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,
 * 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. 
 */

#if defined(ENABLE_FULLSCREEN_API) && ENABLE_FULLSCREEN_API

/* https://fullscreen.spec.whatwg.org/#user-agent-level-style-sheet-defaults */

@namespace "http://www.w3.org/1999/xhtml";

*|*:not(:root):fullscreen {
  position: fixed !important;
  inset: 0 !important;
  margin: 0 !important;
  box-sizing: border-box !important;
  min-width: 0 !important;
  max-width: none !important;
  min-height: 0 !important;
  max-height: none !important;
  width: 100% !important;
  height: 100% !important;
  transform: none !important;

  /* intentionally not !important */
  object-fit: contain;
}

*|*:root:-internal-fullscreen-document:not(:fullscreen) {
    overflow: hidden !important;
}

*|*:fullscreen video,
video:fullscreen {
    -webkit-cursor-visibility: auto-hide;
}

#if defined(WTF_PLATFORM_APPLETV) && WTF_PLATFORM_APPLETV
video:fullscreen {
    /*
     * FIXME: Adding !important improves compatibility when placing video elements in element
     * fullscreen on tvOS, but we should add an -internal pseudo-class to contain styles that are
     * specific to video using element fullscreen.
     */
    object-fit: contain !important;
}
#endif

img:fullscreen {
    width: auto;
    height: 100%;
    max-width: 100%;
}

iframe:fullscreen {
    border: none !important;
    padding: 0 !important;
}

*|*:not(:root):fullscreen::backdrop {
    background: black;
}

*|*:not(:root):-internal-in-window-fullscreen {
    margin: auto !important;
    width: auto !important;
    height: 80vh !important;
    max-width: 100vw !important;
    max-height: 100vh !important;
    border-radius: 20px !important;
    pointer-events: auto !important;
    cursor: auto !important;
}

*|*:not(:root):-internal-in-window-fullscreen::backdrop {
    background: rgba(0,0,0,0.85);
}

#endif