Hello,

Sorry for the late reply.
1-The line below the slider is actually a border. I see this is an added element. If you did not add the custom code then perhaps some plugins you have installed may have added it. Anyway, to remove it please add this code into your custom css box:

@media (max-width: 480px){
.header_wrapper.background--dark {
    border-bottom: none !important;
}}

I don’t see the white border in the side you are mentioning.

2- To remove logo from mobile menu overlapping, please add this code:

@media (max-width: 480px){
#logo {
    left: 65px !important;
}}

Let us know if you need further help.

Have a nice day!