JSFiddle - React, Tailwind, and code Playground

HTML

<div class="header">
    <div class="header_left"></div>
    <div class="header_right"></div>
</div>

CSS

.header {
    min-width: 1000px;
    height: 100px;
}

.header_left {
    float: left;
    width: 300px;
    height: 100%;
    background: #333 url(http://searchengines.guru/customavatars/thumbs/avatar990249_4.gif) no-repeat 50%;
}

.header_right {
    overflow: hidden;
    height: 100%;
    background: #1a1a1a url(http://img.forumimg.net/design/forum-header-inside.png) no-repeat;
}