Make logo in navbar big and centered

Add this to the cell containing CSS in your meta data (purple cells) to make the logo (if applicable) bigger and centered:

.navbar-brand {
   position: absolute;
   left: 50%;
   margin-left: -200px !important;  /* 50% of your logo width */
   display: block;
}

.navbar-header .navbar-brand {
 height: 200px !important;
}

.navbar-brand > img {
max-height: 200px !important;
}

#header {
height: 200px !important;
}

div#content {
   padding-top: 180px;
}