common-styles.html

<dom-module id="common-styles">
  <template>
    <style>
      :host {
        --divider-color: #edf1f4;
        --max-top-image-dimension: 125px;
        --max-bottom-image-dimension: 150px;
        --section-spacer-distance: 20px;

        box-shadow: 0px 5px 10px rgba(0,0,0,0.25);
        display: block;
        font-family: serif;
        padding: calc(var(--section-spacer-distance) * 2) 20px;
        text-align: center;
      }
      /* Image at the top of the document. */
      :host .certificate-image img {
        max-width: var(--max-top-image-dimension);
        max-height: var(--max-top-image-dimension);
      }

      /* Headers section */
      :host .headers::before,
      :host .headers::after {
        content: ' ';
        display: block;
        background-color: var(--divider-color);
        width: 30%;
        height: 1px;
        text-align: center;
        margin: var(--section-spacer-distance) auto;
      }
      :host .headers h1,
      :host .headers h2,
      :host .headers h3 {
        font-weight: normal;
        margin-top: 0px;
        margin-bottom: 0px;
      }
      :host .headers h1 {
        font-size: 30px;
      }
      :host .headers h2 {
        font-size: 24px;
        margin-top: calc(var(--section-spacer-distance) / 2);
      }
      :host .headers h3 {
        font-size: 16px;
        font-style: italic;
        margin-top: calc(var(--section-spacer-distance) / 2);
      }

      /* Description section */
      :host .description p {
        font-style: italic;
        margin-top: var(--section-spacer-distance);
      }

      /* Signatures section*/
      :host .signatures {
        margin-top: var(--section-spacer-distance);
      }
      :host .signatures img {
        max-width: var(--max-bottom-image-dimension);
      }

      /* Image at the bottom of the document. */
      :host .seal {
        margin-top: var(--section-spacer-distance);
      }
      :host .seal img {
        max-width: var(--max-bottom-image-dimension);
        max-height: var(--max-bottom-image-dimension);
      }
    </style>
  </template>
</dom-module>