Mark All Read with Undo

<div class="nuda-nc2-mark-read-undo" role="status" aria-live="polite">
  <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"
       stroke-linecap="round" stroke-linejoin="round" aria-hidden="true">
    <path d="M20 6 9 17l-5-5" />
  </svg>
  <span class="nuda-nc2-mark-read-undo__text">12 marked as read</span>
  <button type="button" class="nuda-nc2-mark-read-undo__undo">Undo</button>
  <span class="nuda-nc2-mark-read-undo__timer" aria-hidden="true"></span>
</div>

.nuda-nc2-mark-read-undo {
  position: relative;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 12px;
  background: #131316;
  border: 1px solid rgba(255,255,255,.1);
  border-radius: 10px;
  color: #fafafa;
  width: 100%;
  max-width: 290px;
  overflow: hidden;
  animation: _nuda-nc2mark-read-undo-in .35s cubic-bezier(.16,1,.3,1) both;
}

.nuda-nc2-mark-read-undo > svg {
  width: 15px;
  height: 15px;
  color: #6ee7b7;
  flex-shrink: 0;
}

.nuda-nc2-mark-read-undo__text {
  flex: 1;
  font-size: 12px;
  color: #cfcfcf;
}

.nuda-nc2-mark-read-undo__undo {
  background: transparent;
  border: 0;
  color: #e4ff54;
  font-size: 11px;
  font-weight: 700;
  cursor: pointer;
  padding: 6px 8px;
  min-height: 32px;
  border-radius: 6px;
  transition: background .2s;
}

.nuda-nc2-mark-read-undo__undo:hover {
  background: rgba(228,255,84,.1);
}

.nuda-nc2-mark-read-undo__undo:focus-visible {
  outline: 2px solid #e4ff54;
  outline-offset: 2px;
}

.nuda-nc2-mark-read-undo__timer {
  position: absolute;
  left: 0;
  bottom: 0;
  height: 2px;
  width: 100%;
  background: #e4ff54;
  transform-origin: right;
  animation: _nuda-nc2mark-read-undo-shrink 5s linear forwards;
}

@keyframes _nuda-nc2mark-read-undo-in {
  from {
    opacity: 0;
    transform: translateY(-6px);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

@keyframes _nuda-nc2mark-read-undo-shrink {
  to {
    transform: scaleX(0);
  }
}

@media (prefers-reduced-motion:reduce) {
  .nuda-nc2-mark-read-undo {
    animation: none;
  }
  .nuda-nc2-mark-read-undo__timer {
    animation: none;
    transform: none;
    opacity: .4;
  }
}