.box {
  height: 360px;
  max-width: 92ch;
  width: 98%;
  border: 1px solid gray;
}

.target_blank:after, a[target="_blank"]:after {
  content: url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAoAAAAKCAYAAACNMs+9AAAAQElEQVR42qXKwQkAIAxDUUdxtO6/RBQkQZvSi8I/pL4BoGw/XPkh4XigPmsUgh0626AjRsgxHTkUThsG2T/sIlzdTsp52kSS1wAAAABJRU5ErkJggg==);
  margin: 0 3px 0 5px;
}

.content {
  max-width: 98ch;
  margin-left: auto;
  margin-right: auto;
}

button {
  background-color: #e7e7e7;
  border: 1px solid gray;
  color: black;
  padding: 4px 25px;
  border-radius: 4px;
  text-align: center;
  text-decoration: none;
  display: inline-block;
  font-size: 12px;
}

button[disabled] {
  color: #999;
}