iframe.css

<style>
    /* 1) Lift the 40rem prose cap on the editorial chain that contains our iframe. */
    .page-node-type-contenu-classement .contenu-classement-content
      > .field--name-field-contenu-editorial:has(iframe[src*="infog-index.rsf.org"]),
    .page-node-type-contenu-classement .contenu-classement-content
      > .field--name-field-contenu-editorial > .field__item:has(.paragraph--type--texte-riche > .field--name-field-texte-riche > iframe[src*="infog-index.rsf.org"]) {
      max-width: none !important;
      width: 100% !important;
    }

    /* 2) Restore the 40rem cap on every sibling paragraph (those without our iframe). */
    .page-node-type-contenu-classement .contenu-classement-content
      > .field--name-field-contenu-editorial:has(iframe[src*="infog-index.rsf.org"])
      > .field__item
      > .paragraph:not(:has(iframe[src*="infog-index.rsf.org"])) {
      max-width: 40rem;
      margin-left: auto;
      margin-right: auto;
    }

    /* 3) Bleed the iframe paragraph past the container's L/R padding (responsive). */
    .page-node-type-contenu-classement .contenu-classement-content
      .paragraph--type--texte-riche:has(> .field--name-field-texte-riche > iframe[src*="infog-index.rsf.org"]) {
      max-width: none !important;
      width: calc(100% + 3rem) !important;
      margin-left: -1.5rem !important;
      margin-right: -1.5rem !important;
      margin-top: 2rem !important;
      margin-bottom: 2rem !important;
    }

    @media (min-width: 992px) {
      .page-node-type-contenu-classement .contenu-classement-content
        .paragraph--type--texte-riche:has(> .field--name-field-texte-riche > iframe[src*="infog-index.rsf.org"]) {
        width: calc(100% + 12rem) !important;
        margin-left: -6rem !important;
        margin-right: -6rem !important;
        margin-top: 3rem !important;
        margin-bottom: 3rem !important;
      }
    }

    /* 4) Stretch the inner rich-text wrapper and the iframe itself. */
    .page-node-type-contenu-classement .contenu-classement-content
      .paragraph--type--texte-riche:has(> .field--name-field-texte-riche > iframe[src*="infog-index.rsf.org"])
      > .field--name-field-texte-riche {
      max-width: none !important;
      width: 100% !important;
    }

    .page-node-type-contenu-classement .contenu-classement-content
      .paragraph--type--texte-riche:has(> .field--name-field-texte-riche > iframe[src*="infog-index.rsf.org"])
      > .field--name-field-texte-riche > iframe[src*="infog-index.rsf.org"] {
      display: block;
      width: 100%;
      max-width: 100%;
      border: 0;
      min-height: 80vh;
    }
  </style>