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

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

@font-face {
  font-family: 'Win98Bitmap';
  src: url('ms_sans_serif.woff2') format('woff2'),
       url('ms_sans_serif.ttf') format('truetype');
  font-weight: normal;
  font-style: normal;
  font-display: swap;
}

body {
  background: #008080;
  display: flex;
  justify-content: center;
  align-items: center;
  font-family: 'Win98Bitmap', sans-serif;
}

.window {
  background: #c0c0c0;
  border: 2px solid #000;
  box-shadow: inset -1px -1px #fff, inset 1px 1px #808080;
  width: 400px;
  padding: 10px;
}

.title-bar {
  background: #000080;
  color: #fff;
  padding: 2px 5px;
  font-weight: bold;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: 'Win98Bitmap', sans-serif;
}

.title-bar button {
  background: #c0c0c0;
  border: 1px solid #808080;
  width: 16px;
  height: 16px;
  font-size: 12px;
  line-height: 14px;
  cursor: pointer;
}

.content {
  background: #c0c0c0;
  padding: 15px;
  border: 2px solid #808080;
  box-shadow: inset -1px -1px #fff, inset 1px 1px #808080;
  text-align: center;
  font-family: 'Win98Bitmap', sans-serif;
}

.btn {
  background: #c0c0c0;
  border: 2px solid #fff;
  border-right-color: #808080;
  border-bottom-color: #808080;
  padding: 4px 12px;
  margin-top: 10px;
  cursor: pointer;
  font-family: 'Win98Bitmap', sans-serif;
}

.btn:active {
  border: 2px solid #808080;
  border-right-color: #fff;
  border-bottom-color: #fff;
}