Hello,

1-I added this code into your custom css box:

@media (max-width: 480px){
#logo { left: -48px !important;}
.codeless_slider_wrapper {min-height: 300px !important;}
.codeless-slider-container.swiper-parent.swiper_slider.codeless_slider {height: 300px !important;}
.codeless_slider_swiper {
    height: 300px !important;
    min-height: 300px !important;
}
}

Result.
2-Please go to file css/bootstrap-responsive.css and find these lines:

#logo{float:right;left:0 !important; right:0 !important; -webkit-transform: none !important;
     -moz-transform: none !important;
      -ms-transform: none !important;
       -o-transform: none !important;
          transform: none !important;
  }

Replace left:0 !important; with this left:0px; Save file.
3-You needed to activate responsive menu for it to display. It is located in Header Options > Show Responsive Menu Dropdown. I already set it ON for you.

Best regards!