.masthead {
    position: relative;
}
.masthead-video {
    z-index: 0;
}


.sound img {
    width: 40px;
}
.mail img {
    width: 40px;
}

.sound {
    position: absolute;
    z-index: 10;
    width: 40px;
    height: 20px;
    right: 40px;
    top: 10px;
}

.mail {
    position: absolute;
    z-index: 10;
    width: 40px;
    height: 20px;
    right: 20px;
    top: 10px;
}
.sound {
    position: absolute;
    z-index:5;
    width: 100px;

}
.sound button {
    width: 40px;
    height: 40px;
    border: none;
    color: #fff;
    text-align: center;
    background: none;
    outline: none;
}
.sound-on {
    display: block;
}
.sound-off {
    display: none;
}

.mobile {
    width: 100%;
    height: 100%;
    background: #000;
    display: flex;
    justify-content: center;
    position: absolute;
    justify-items: center;
}
.mobile video {
    width: 100%;
}