JSFiddle - React, Tailwind, and code Playground

HTML

<a href="#win1" rel="nofollow" class="sf">Открыть окно 1</a>
<div class="popup" id="win1">Здесь то, что будет в окне.
  <a class="close sf" title="Закрыть" href="#close"></a>
</div>


<a href="#win2" rel="nofollow" class="sf">Открыть окно 2</a>
<div class="popup" id="win2">Что будет в окне.
  <a class="close sf" title="Закрыть" href="#close"></a>
</div>

CSS

.overlay {
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  z-index: 10;
  display: none;
  background-color: rgba(0, 0, 0, 0.65);
  position: fixed;
  cursor: default
}

.overlay:target {
  //display: block
}

.popup {
  top: -100%;
  right: 0;
  left: 50%;
  font-size: 14px;
  z-index: 20;
  margin: 0;
  width: 85%;
  min-width: 320px;
  max-width: 600px;
  position: fixed;
  padding: 15px;
  border: 1px solid #383838;
  background: #FEFEFE;
  -webkit-border-radius: 4px;
  -moz-border-radius: 4px;
  -ms-border-radius: 4px;
  border-radius: 4px;
  font: 14px/18px 'Tahoma', Arial, sans-serif;
  -webkit-box-shadow: 0 15px 20px rgba(0, 0, 0, .22), 0 19px 60px rgba(0, 0, 0, .3);
  -moz-box-shadow: 0 15px 20px rgba(0, 0, 0, .22), 0 19px 60px rgba(0, 0, 0, .3);
  -ms-box-shadow: 0 15px 20px rgba(0, 0, 0, .22), 0 19px 60px rgba(0, 0, 0, .3);
  box-shadow: 0 15px 20px rgba(0, 0, 0, .22), 0 19px 60px rgba(0, 0, 0, .3);
  -webkit-transform: translate(-50%, -500%);
  -ms-transform: translate(-50%, -500%);
  -o-transform: translate(-50%, -500%);
  transform: translate(-50%, -500%);
  -webkit-transition: -webkit-transform .6s ease-out;
  -moz-transition: -moz-transform .6s ease-out;
  -o-transition: -o-transform .6s ease-out;
  transition: transform .6s ease-out
}

.popup:target {
  -webkit-transform: translate(-50%, 0);
  -ms-transform: translate(-50%, 0);
  -o-transform: translate(-50%, 0);
  transform: translate(-50%, 0);
  top: 20%
}

.close {
  top: -10px;
  right: -10px;
  width: 20px;
  height: 20px;
  position: absolute;
  padding: 0;
  border: 2px solid #CCC;
  -webkit-border-radius: 15px;
  -moz-border-radius: 15px;
  -ms-border-radius: 15px;
  -o-border-radius: 15px;
  border-radius: 15px;
  background-color: rgba(61, 61, 61, 0.8);
  -webkit-box-shadow: 0 0 10px #000;
  -moz-box-shadow: 0 0 10px #000;
  box-shadow: 0 0 10px #000;
  text-align: center;
  text-decoration: none;
  font: 13px/20px 'Tahoma', Arial, sans-serif;
  font-weight: bold;
  -webkit-transition:...

JavaScript

$(document).ready(function() {
  $('a[href^="#"], a[href^="."]').not('.sf').click(function() {
    var t = $(this).attr("href");
    return 0 != $(t).length && $("html, body").animate({
      scrollTop: $(t).offset().top
    }, 1500), !1
  })
});