:root {
  --modal-duration: 1s;
}

.modal {
  display: none;
  position: fixed;
  z-index: 1;
  left: 0;
  top: 0;
  height: 100%;
  width: 100%;
  overflow: auto;
  background: rgba(0, 0, 0, 0.5);
}

.modal-content {
  background: #fff;
  text-align: center;
  margin: 10% auto;
  width: 350px;
  border-radius: 10px;
  padding: 3rem;
  box-shadow: 0 5px 8px 0 rgba(0, 0, 0, 0.2), 0 7px 20px 0 rgba(0, 0, 0, 0.17);
  animation-name: modalopen;
  animation-duration: var(--modal-duration);
}

.modal-content h1 {
  margin-bottom: 1rem;
}

.modal-content p {
  font-size: 1.2rem;
  margin-top: 1rem;
}

@keyframes modalopen {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}