JSFiddle - React, Tailwind, and code Playground

HTML

<div class="panel-footer table">
    <span style="width:100%;" class="header-footer-item">
        <div class="cell"></div><!-- Empty div to fill the left-->
        <div class="cell-min-width">
          <button class="" type="button">Save</button>
        </div>  
    </span>    
</div>

CSS

.panel-footer {
    height: 70px;
    vertical-align: middle;
    border: solid;
}

.header-footer-item {
    display: inline-block;
    line-height: 70px;
    border: solid red;

}

.align-right {
	float: right;
}

.align-middle {
  vertical-align: middle;
}
.table {
    display: table;
    width: 100%;
}

.row {
    display: table-row;
    width: 100%;
}

.cell {
    display: table-cell;
}

.cell-min-width {
    display: table-cell;
    width: 1%;
}