index.css

/* Page Layout */
body {
  font-family: OpenSans, Arial;
  color: #555;
  margin: 0;
}
h1 {
  text-align: center;
  background: #f5f5f5;
  padding: 1rem;
  box-shadow: 0 0 3px rgba(0, 0, 0, .3);
}
article {
  max-width: 1200px;
  margin: 5rem auto;
  padding-bottom: 5rem;
  border-bottom: 1px solid #999;
  gap: 1rem;
}
article > section {
  background-color: #f5f5f5;
  padding: 2rem;
  box-shadow: 1px 1px 3px rgba(0, 0, 0, .3);
}
article p {
  margin-bottom: 1rem;
  padding-bottom: 1rem;
  border-bottom: 1px dotted #ccc;
}

/* Used within components */
button {
  background-color: #2a85d2;
  border-radius: 5px;
  border: none;
  color: white;
  font-size: 3rem;
  text-align: center;
  padding: 0 1rem;
  cursor: pointer;
}

button.reset {
  font-size: 1rem;
  margin-left: 5rem;
}

progress {
  display: block;
  width: 100%;
}

/* Only reference span within the component, not in the HTML page */
:host(x-counter) span {
  display: inline-block;
  font-size: 2rem;
  padding: 2rem;
  width: 50px;
  text-align: right;
}

/* code embedded */

.emgithub-container {
  margin: 0 !important;
}

@media screen and (min-width: 1200px) {
  article {
    display: flex;
  }
  article > section {
    width: 50%;
  }
  article > aside {
    width: 50%;
  }
}