JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js">
</script>

<article class="alert-box" id="alert-box-news">
  <h1>News Alerts</h1>
  <p>text text text text text text text text text text text text text text</p>
  <a class="alert-box-close" id="close-alert-box-news">
    <img src="http://i.imgur.com/czf8yas.png" height="25" width="25" alt="">
  </a>
</article>

<article class="alert-box" id="alert-box-maintenance">
  <h1>Site Maintenance</h1>
  <p>text text text text text text text text text text text text text text</p>
  <a class="alert-box-close" id="close-alert-box-maintenance">
    <img src="http://i.imgur.com/czf8yas.png" height="25" width="25" alt="">
  </a>
</article>

CSS

.alert-box {
  width: 50vw;
  position: relative;
  margin: 20px auto;
  border: 1px solid black;
}
.alert-box-close {
  position: absolute;
  top: -12px;
  right: -12px;
  cursor: pointer;
}

JavaScript

$(document).ready(function() {
  checkCookie("alertDisplayed")
  $("#close-alert-box-news").click(function() {
    setCookie("alertDisplayed", 'yes', 1); 
    $(".alert-box").hide(800);
  });
  $("#close-alert-box-maintenance").click(function() {
    setCookie("alertDisplayed", 'yes', 1); 
    $(".alert-box").hide(800);
  });
});

function setCookie(cname, cvalue, exdays) {
    var d = new Date();
    d.setTime(d.getTime() + (exdays*24*60*60*1000));
    var expires = "expires="+ d.toUTCString();
    document.cookie = cname + "=" + cvalue + ";" + expires + ";path=/";
}

function checkCookie(cname) {
    var name = cname + "=";
    var ca = document.cookie.split(';');
    for(var i = 0; i <ca.length; i++) {
        var c = ca[i];
        while (c.charAt(0)==' ') {
            c = c.substring(1);
        }
        if (c.indexOf(name) == 0) {
            $(".alert-box").hide();
        }
    }
    return;
}