.overlay { display: none; width: 100%; height: 100%; background: rgba(0,0,0,0.6); position: fixed; z-index: 1 } .btn_area { width: 400px; height: 250px; position: absolute; top: 50%; left: 50%; transform: translate(-50%,-50%); background: #fff; text-align: center; z-index: 2 } .btn_area .ttl { font-weight: bold } .btn_area p { padding: 15px } .btn_area button { display: block; margin: 0 auto; background: #333; color: #fff; padding: 20px 40px; border: none } .btn_area button:hover { background: #777 }