style.css

body {
  padding: 0;
  margin: 0;
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  color: white;
}

#menu-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 30px;
  background: #34475a;
  -webkit-app-region: drag;
}

#menu-bar > div {
  height: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.menubar-btn {
  -webkit-app-region: no-drag;
}

.container {
  height: calc(100vh - 30px);
  background: #34475ab0;
  color: white;
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: 2em;
}

button {
  height: 100%;
  padding: 0 15px;
  border: none;
  background: transparent;
  outline: none;
}

button:hover {
  background: rgba(221, 221, 221, 0.2);
}

#close-btn:hover {
  background: rgb(255, 0, 0);
}

button i {
  color: white;
}