You have to increase the width of the menu for as much as you want, but you should put the same menu size in translate.
Where 200px is the size of the MENU, it has to be the same.
.pushy-left {
-webkit-transform: translate3d(-200px, 0, 0);
-ms-transform: translate3d(-200px, 0, 0);
transform: translate3d(-200px, 0, 0);
}
.pushy-open-left #container,
.pushy-open-left .push {
-webkit-transform: translate3d(200px, 0, 0);
-ms-transform: translate3d(200px, 0, 0);
transform: translate3d(200px, 0, 0);
}
.pushy-right {
-webkit-transform: translate3d(200px, 0, 0);
-ms-transform: translate3d(200px, 0, 0);
transform: translate3d(200px, 0, 0);
}
.pushy-open-right #container,
.pushy-open-right .push {
-webkit-transform: translate3d(-200px, 0, 0);
-ms-transform: translate3d(-200px, 0, 0);
transform: translate3d(-200px, 0, 0);
}