batharoy

Thats where the current_page_item comes in.

#nav .menu > ul > .current_page_item > a {
background: blue;
}

For solid colors:

#nav a {
background: red;
}
#nav .menu > ul > .current_page_item > a {
background: blue;
}

To get a gradient follow the example:

background: -webkit-linear-gradient(red, blue); /* For Safari */
background: -o-linear-gradient(red, blue); /* For Opera 11.1 to 12.0 */
background: -moz-linear-gradient(red, blue); /* For Firefox 3.6 to 15 */
background: linear-gradient(red, blue); /* Standard syntax */

That plugin did work for me when transferring to a new directory on the same localhost

I’d still be interested to know how to set the background colour

#site-header {
    background: red;
}

For the search:
Do want it in the top-right or bottom-right? That will determine placement of the code in the file. Either way copy your header.php file from your parent folder into your child folder.

Shopping:
woocommerce does not work out of the box but following this video I did get it to work.

I also had no problems with IE 11 on Windows 7.

.entry.single img {
max-width: 100%;
}

You can put it at the bottom of your child css file.

.entry-title {
    text-transform: none;
}