.header{display:flex;justify-content:space-between;align-items:center;padding:10px 20px;background-color:#f8f9fa;border-bottom:1px solid #e9ecef}.footer{background-color:#282c34;color:#fff;text-align:center;padding:10px;position:fixed;bottom:0;width:100%}*{margin:0;padding:0;box-sizing:border-box}#app{text-align:center}