JSFiddle - React, Tailwind, and code Playground

HTML

<div class="formInput">
    <div class="icon left"><img src="" alt="x" /></div>
    <div class="inp">
        <input type="text" name="username" placeholder="Benutzername" />
    </div>
</div>

CSS

.left { float: left; }
.right { float: right; }
.clear { clear: both; }

.formInput {
	width: 420px;
	height: 30px;
	border: 2px solid #e4e4e4;
	margin-bottom: 10px;
}
.formInput .icon {
	background-color: #fafafa;
}
.formInput .icon img {
    width: 30px;
    height: 30px;
}
.formInput .inp input, .formInput .inp select {
	background-color: transparent;
	width: 383px;
	height: 30px;
	border: none;
	border-left: 2px solid #e4e4e4;
	padding-left: 5px;
    outline: 0 !important;
}