*{
    border: 0; margin: 0; padding: 0; box-sizing: border-box;
}
body{
    background-color: sandybrown; font-family: verdana;
}
#container{
    width: 1400px; height: 900px; border: 4px solid gray;
    border-radius: 4px;
    margin: 20px auto;
    background-image: url(phoneframes.png);
    background-repeat: no-repeat;
    background-color: white;
    background-position: center;
    position: relative;
}
#phoneframe1, #phoneframe2, #phoneframe3{
    border: 2px solid hsla(10,100%,50%,80%);
    position: absolute;
}
#mainbutton{
    position: absolute; top: 0px; left: -105px;
    width: 100px; height: 100px;
    border: 1px outset red;
    text-align: center;
    cursor: pointer;
    background-color: aliceblue;
}
header{
    background-color: #456;
    height: 60px;
    position: relative;
}
header button{
    position: absolute;
    right: 12px; top: 4px;
    width: 50px; height: 50px;
    border: 4px outset #222;

}
button:hover{
    cursor: pointer;
}
nav.mobilemenu li{
    border-bottom: 1px solid black;
    list-style-type: none;
    height: 50px;
}
nav.mobilemenu a{
    display: block; height: 100%;
    font-size: 25px;
    text-decoration: none;
    line-height: 50px;
    text-indent: .5em;
}

/* single frames*/
/* single frame 1*/
#phoneframe1{
    top: 69px; left: 67px;
    width: 384px;height: 791px;
    border-radius: 6px 6px 36px 36px;
}
#phoneframe1 nav.mobilemenu{
    background-color: hsla(90, 100%, 50%, 70%);
    height: calc(100% - 70px);
    position: relative;
}

#phoneframe1 nav.mmclosed{
    display: none;
}
#phoneframe1 nav.mmopen{
    position: absolute;top: 60px; left: 0px;
    width: 100%;
}

/* single frame 2*/
#phoneframe2{
    top: 112px; left: 614px;
    width: 321px;height: 557px;
    border-radius: 3px 3px 3px 3px;
}
#phoneframe2 nav a span{
    display: none;
}
#phoneframe2 nav.mmclosed{
    display: none;
}
/* single frame 3*/
#phoneframe3{
    top: 112px; left: 1093px;
    width: 233px;height: 395px;
    border-radius: 2px 2px 2px 2px;
}
#phoneframe3 nav a span{
    display: none;
}
#phoneframe3 nav.mobilemenu li{
    border-bottom: 1px solid black;
    list-style-type: none;
    height: 25px;
}
#phoneframe3 nav.mobilemenu a{
    display: block; height: 100%;
    font-size: 15px;
    text-decoration: none;
    line-height: 25px;
    text-indent: .5em;
}
#phoneframe3 nav.mmclosed{
    display: none;
}
/* single frames end*/