chromium/src/third_party/blink/renderer/modules/media_controls/resources/mediaInterstitials.css

/* Copyright 2018 The Chromium Authors. All rights reserved.
   Use of this source code is governed by a BSD-style license that can be
   found in the LICENSE file. */

video::-internal-media-interstitial {
    width: inherit;
    height: inherit;
    position: relative;
    direction: ltr;
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    align-items: center;
    /* The font size is set to be proportional to the viewport width.
     * Specifically, it is 15px for 400px width, and 36px for 1920px width.
     * The full math expression is:
     * 15px + (36 - 15) * ((100vw - 400px) / (1920 - 400)).
     */
    font-size: calc(9.5px + 1.38vw);
    background-color: transparent;
    opacity: 0;
    transition: opacity .3s ease-in-out;
}

video::-internal-media-interstitial-background-image {
    display: flex;
    position: absolute;
    margin: 0;
    top: 0px;
    left: 0px;
    width: 100%;
    height: 100%;
    border: none;
    border-width: 0px;
    background-color: transparent;
    padding: 0;
    filter: grayscale(100%) blur(5px) opacity(40%);
}

video::-internal-media-remoting-cast-icon {
    -webkit-appearance: none;
    background-size: 100% 100%;
    background-repeat: no-repeat;
    background-position: center center;
    display: flex;
    position: absolute;
    margin: 0px;
    border-width: 0px;
    background-color: transparent;
    height: 2.5vw;
    width: 3vw;
    padding: 0px;
    left: calc(50% - 1.5vw);
    top: calc(50% - 3vw);
}

video::-internal-media-interstitial-message,
video::-internal-picture-in-picture-interstitial-message {
    display: inline;
    position: absolute;
    top: calc(50% + 1vw);
    border: none;
    color: rgba(255,255,255,.54);
    width: 100%;
    text-wrap: none;
    text-align: center;
    background-color: transparent;
    font-family: Roboto-Regular, Sans-serif, Segoe, Serif, Helvetica;
    padding: 0px;
    margin: 0px;
}

video::-internal-media-interstitial-message {
    font-size: 90%;
}

video::-internal-picture-in-picture-interstitial-message {
    top: 0;
    left: 0;
    width: auto;

    color: rgba(255,255,255,0.8);
    text-align: left;
    letter-spacing: 0.2px;

    /** default to small */
    font-size: 14px;
    line-height: 20px;
    margin: 8px 16px;
}

video::-internal-media-remoting-toast-message {
    display: inline;
    position: absolute;
    top: 16pt;
    border: none;
    border-radius: 2pt;
    color: rgba(255,255,255, 1);
    width: auto;
    text-wrap: none;
    text-align: center;
    background-color: rgba(40, 44, 50, 0.7);
    font-size: 90%;
    font-family: Roboto-Regular, Sans-serif, Segoe, Serif, Helvetica;
    padding: 10pt 24pt 10pt 24pt;
    margin: 0px;
}

video::-internal-media-remoting-cast-icon {
    background-image: -webkit-image-set(
      url(default_100_percent/mediaremoting_cast.png) 1x,
      url(default_200_percent/mediaremoting_cast.png) 2x);
}

video::-internal-picture-in-picture-interstitial-message.sizing-medium {
    font-size: 24px;
    line-height: 28px;
    margin: 32px 64px;
}

video::-internal-picture-in-picture-interstitial-message.sizing-large {
    font-size: 40px;
    line-height: 47px;
    margin: 64px 96px;
}