JSFiddle - React, Tailwind, and code Playground

HTML

<header>
      <div class="container">
        <div class="header-left">
          <img class="logo" src="../../Pictures/ki.png">
        </div>
        <div class="header-right">
          <a href="#" class="login">ログイン</a>
        </div>
      </div>
    </header>

CSS

header{
    height: 65px;
    width: 100%;
    background-color: rgba(34, 49, 52, 0.9);
}
.container{
    width: 1170px;
    padding: 0 15px;
    margin: 0 auto;
}
.header-left{
    float:left;
}
.header-right{
    float:right;
}