body {
            margin: 0;
            background: #000;
        }

        video {
            position: fixed;
            top: 50%;
            left: 50%;
            min-width: 100%;
            min-height: 100%;
            width: auto;
            height: auto;
            z-index: -100;
            transform: translateX(-50%) translateY(-50%);
            background: url('') no-repeat;
            background-size: cover;
            transition: 1s opacity;
        }

        .stopfade {
            opacity: .5;
        }

        #polina {
            font-family: Agenda-Light, Agenda Light, Agenda, Arial Narrow, sans-serif;
            font-weight: 100;
            background: rgba(0, 0, 0, 0.3);/*(0, 0, 0, 0.3);*/
            color: white;
            padding: 2rem;
            width: 33%;
            margin: 2rem;
            float: right;
            font-size: 1.2rem;
        }

        h1 {
            font-size: 3rem;
            text-transform: uppercase;
            margin-top: 0;
            letter-spacing: .3rem;
        }

        #polina button {
            display: block;
            width: 80%;
            padding: .4rem;
            border: none;
            margin: 1rem auto;
            font-size: 1.3rem;
            background: rgba(255, 255, 255, 0.23);
            color: #fff;
            border-radius: 3px;
            cursor: pointer;
            transition: .3s background;
        }

        #polina button:hover {
            background: rgba(0, 0, 0, 0.5);
        }

        a {
            display: inline-block;
            color: #fff;
            text-decoration: none;
            background: rgba(0, 0, 0, 0.5);
            padding: .5rem;
            transition: .6s background;
        }

        a:hover {
            background: rgba(0, 0, 0, 0.9);
        }

        @media screen and (max-width: 500px) {
            div {
                width: 70%;
            }
        }

        @media screen and (max-device-width: 800px) {
            html {
            /*ここのurl()の中に画像のパスを指定すると、読み込んだときに一瞬その画像が表示される*/
                background: url() #000 no-repeat center center fixed;
            }

            #bgvid {
                display: none;
            }
        }