Full Width header logo?

I am trying to get an image that is 1380×350 pixels to take up the whole header area of the Hueman theme,

I have tried everything I can think of…such as…

.site-title {
	float: none;
	margin:10px 0 0px 0;
}

Also putting 

.site-title img {
	min-width:350px
}

I can get it to fix in firebug but when I use the same CSS it doesnt translate to what I see in my browser.

Here is the snippet from the theme source:

<header id="header">

		<div class="container group">
			<div class="container-inner">

				<div class="group pad">
					<h1 class="site-title"><a href="https://orlando-real.estate/" rel="home"><img src="https://orlando-real.estate/wp-content/uploads/2014/07/logo-header.png" alt="Ian L Terry - Realtor? - Orlando Real Estate"></a></h1>
									</div>

….and the CSS child theme I made…

/*
 Theme Name:   Hueman Child
 Theme URI:    https://www.orlando-real.estate/wp-content/themes/hueman-child/
 Description:  Hueman Child Theme
 Author:       Ian L Terry
 Author URI:   https://www.orlando-real.estate/
 Template:     hueman
 Version:      1.0.0
 Tags:         resultventure, orlando real estate
 Text Domain:  hueman Child
*/

@import url("../hueman/style.css");
@import url("../hueman/responsive.css");

/* =Theme customization starts here
-------------------------------------------------------------- */

/*-------------------------------------------*
/*Body, Common Classes &Structure
/*-------------------------------------------*/

/*
body {
  background-color: #fff;
  background-image: url('###');
  background-repeat:no-repeat;
  background-size:100% 100%;
}

*/

.site-title {
	float: none;
	margin:10px 0 0px 0;
}

.float-right {
	float:right;
	padding-left:10px;
}

.float-left {
	float:left;
	padding-right:10px;
}

.centerIt
{
	margin: 0;
	padding: 0;
	text-align:center;
}

/* #bottom-strip {
	margin: 10px 0 10px 0;
}

.sidebar{
	background-color: #f0f0f0;
}

*/

#nav-topbar,
#nav-header { text-align: center; }

#header .pad { padding-top: 0; padding-bottom: 0; padding-left: 0;}
.site-title { padding: 0; float: center; }

#meta-2 {
	display: inline;
}

#cal-disclaimer {
font-size:.5em;
}

Please help!

Thank you!