Insert navbar inside the header.

Hello!

I’ve been trying for many days how could this possible and I always failed. What I want to do is insert navigation bar inside the logo as same the picture below. I can’t buy the premium for while, but I woul appreciate so much if someone could help me to do that with some CSS.

Link

I tried this CSS trick, but this only put the navbar beside from the logo.

.nav-float-right .inside-header .main-navigation {
    float: none;
    display: inline-block;
    vertical-align: middle;
}

Thank you!