* { 
   margin: 0; 
   padding: 0; 
   box-sizing: border-box; 
}

html, body { 
   overflow: hidden; 
   height: 100%; 
   width: 100%; 
}

.app, .terminal { 
   position: absolute;
   top: 0;
   left: 0;
   width: 100%;
   height: 100%;
   border: none;
}

.app {
   display: none;
   z-index: 1;
}

.terminal {
   display: block;
   z-index: 2;
}

.button {
   display: none;
   position: fixed;
   top: 1px;
   left: 1px;
   will-change: transform;
   width: 55px;
   height: 55px;
   border: 1px solid;
   border-radius: 50%;
   cursor: move;
   z-index: 9999;
   user-select: none;
   touch-action: none;
}

.button:active {
   border: none;
   background: blue;
   box-shadow: 0 0 25px blue;
}