body {
  background: #008080;
  margin: 0;
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
}

/* ウィンドウ */
.window {
  background: #c0c0c0;
  width: 640px;
  height: 420px;
  display: flex;
  flex-direction: column;
  border: 2px solid;
  border-color: #ffffff #404040 #404040 #ffffff;
}

/* タイトルバー */
.title-bar {
  background: #000080;
  color: white;
  font-family: "MS Gothic", monospace;
  padding: 4px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.window-controls {
  display: flex;
  gap: 2px;
}

.window-controls button {
  width: 22px;
  height: 22px;
  background: #c0c0c0;
  border: 2px solid;
  border-color: #ffffff #404040 #404040 #ffffff;
  font-weight: bold;
  cursor: pointer;
}

.window-controls button:active {
  border-color: #404040 #ffffff #ffffff #404040;
}

/* メニュー */
.menu-bar {
  background: #c0c0c0;
  padding: 2px;
  border-bottom: 2px solid;
  border-color: #ffffff #404040 #404040 #ffffff;
}

/* テキスト */
textarea {
  flex: 1;
  resize: none;
  border: 2px solid;
  border-color: #404040 #ffffff #ffffff #404040;
  font-family: "MS Gothic", monospace;
  font-size: 16px;
  padding: 6px;
  outline: none;
}