Content-type: text/html

<div class="centered">
   <p>
   <svg class="icon" xmlns="http://www.w3.org/2000/svg" width="20" height="20" viewBox="0 0 20 20">
     <title>
       alert
     </title>
     <style type="text/css">* { fill: #fc3 }</style>
     <path d="M19.64 16.36L11.53 2.3A1.85 1.85 0 0 0 10 1.21 1.85 1.85 0 0 0 8.48 2.3L.36 16.36C-.48 17.81.21 19 1.88 19h16.24c1.67 0 2.36-1.19 1.52-2.64zM11 16H9v-2h2zm0-4H9V6h2z"/>
   </svg>
   Something went wrong
   </p>
   <p>Error ID: <span class="error-id">r7IIX28MmQtcXT90</span></p>
</div>

<style>
body {
   font-family: sans-serif;
}

.icon {
   position: relative;
   top: 4px;
}

div.centered {
   text-align: center;
   top: 50%;
   position: absolute;
   width: 98%;
   transform: translateY(-50%);
   line-height: 28px;
   background: white;
}

.error-id {
   font-weight: bold;
}
</style>