h1 width vs fixed div width

by rwone

HTML

<div id="mobile_wrapper">
<div id="mobile_menu">
menu
</div>
<div id="mobile_logo">
<img src="http://lorempixel.com/image_output/technics-q-c-150-50-6.jpg">
</div>
<ul id="mobile_cart">
<li>i</li>
<li>i</li>
</ul>
</div>
<h1>
TITLE
</h1>

CSS

#mobile_wrapper {
  background: #000;
  display: block;
  position: fixed;
  width: 95%;
  white-space: nowrap;
  z-index: 5;
  box-sizing: border-box;
  top:0;
  left:0;
}

#mobile_menu {
  background: aqua;
  float: left;
  display:inline-block;
  position:static;
  box-sizing:border-box;
  width:60px;
}

#mobile_logo {
  background: red;
  float: left;
  display:inline-block;
  position:static;
  box-sizing:border-box;
  width: calc(100% - 120px);
  text-align:center;
}

#mobile_logo img {
  max-width: 100%;
  vertical-align: bottom;
}

#mobile_cart {
  width:60px;
  background: green;
  float: left;
  display:inline-block;
  position:static;
  box-sizing:border-box;
  margin:0;
  padding:0;
  text-align:right;
}

#mobile_cart li {
  display: inline;
  list-style: none;
}

h1 {
  width: 95%;
  background: gold;
  display:inline-block;
  position:static;
  box-sizing:border-box;
  margin-top: 50px;
  text-align: center;
}