html, body {
    -webkit-touch-callout: none; /* iOS Safari */
    -webkit-user-select: none;   /* Chrome all / Safari all */
    -khtml-user-select: none;    /* Konqueror HTML */
    -moz-user-select: none;      /* Firefox all */
    -ms-user-select: none;       /* IE 10+ */
    -o-user-select: none;        /* Opera */
    user-select: none;           /* Likely future */
}