@-webkit-keyframes alertstripes {
  to {
    background-position: 70px 0;
  }
}
@keyframes alertstripes {
  to {
    background-position: 70px 0;
  }
}
* {
  box-sizing: border-box;
}

body {
  --alert: #cc9900;
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  color: #fff;
  background: #000000;
  font-family: Helvetica, Arial, sans-serif;
  line-height: 1.2;
}

aside {
  width: 70%;
  max-width: 600px;
  border: 2px solid var(--alert);
}

aside time {
  font-style: italic;
}

aside h4 {
  text-align: center;
  font-size: 1.4rem;
  padding: 1rem 0;
  background: var(--alert);
  margin: 0;
}

h4[role=alert] {
  text-shadow: 1px 1px 5px black;
  background-image: url(https://s3-us-west-2.amazonaws.com/s.cdpn.io/4273/stripe.svg);
  background-size: 70px 100%;
  background-repeat: repeat-x;
  -webkit-animation: alertstripes 2s linear infinite;
          animation: alertstripes 2s linear infinite;
}

aside p {
  padding: 0.1rem 2rem;
  font-size: 1.2rem;
  line-height: 1.4;
}