Seems you have added an Additional CSS already to your site

Please you can try this CSS, regarding menu width you can adjust the value in .sidr

.sidr{
width: 200px !important;
}

.custom-logo-link{
max-width: 100% !important;
left: auto !important;
float: none !important;
}

@media only screen and (max-width: 1023px){
.custom-logo-link img {
max-width: 50% !important;
left: auto !important;
}
}

@media (max-width: 480px){
.custom-logo-link {
left: auto !important;
}
}

@media only screen and (max-width: 767px){
.site-branding {
text-align: center !important;
}
}

@media screen and (min-width: 1024px) {
.container{
max-width: 1300px;
width: 100%;
}
#main-nav{
float: none;
}
.container #primary-menu{
display: flex;
flex-wrap: wrap;
justify-content: center;
align-items: center;
width: 100%;
left: 0;
}
}