#htform-reply-box { position: fixed; inset: 0; background: rgba(0,0,0,.45); z-index: 100000; display: flex; align-items: center; justify-content: center; }
#htform-reply-box[hidden] { display: none; }
#htform-reply-box > div { background: #fff; border-radius: 8px; padding: 20px; width: min(520px,92vw); max-height: 90vh; overflow-y: auto; }
#htform-reply-box h2 { margin-top: 0; }