app.css

       body {
            margin-left: 15px;
            margin-right: 15px;
        }

        .hidden-btn {
            display: none;
        }

        .hidden-btn-parent:hover .hidden-btn {
            display: block;
        }

        .hidden-btn-parent:hover {
            background-color: #fff3b5 !important;
        }

        .address-bar {
            position: fixed;
            height: 60px;
            background-color: white;
            z-index: 999;
            padding-top: 15px;
            margin-right: 15px;
            /*margin-top: 30px;*/
        }

        .bottom-bar {
            position: fixed;
            bottom: 0;
            padding-bottom: 10px;
            margin-right: 15px;
            background-color: white;
        }

        .files-box {
            margin-top: 50px;
            margin-bottom: 30px;
        }

        .overlay {
            top: 5px;
            margin-left: -12px;
        }
        .new-dir-input {
                margin-bottom: -3px;

        }
        .new-dir-input{
            width: 10px;
            -webkit-transition: width 0.4s ease-in-out;
            transition: width 0.4s ease-in-out;
        }
        /* When the input field gets focus, change its width to 100% */
        .new-dir-input:focus {
            width: 60vw;
        }