Phone 320px: list grids with a 290-420px minimum column use minmax(min(N, 100%), 1fr), so a single column fits a 320px screen (#78)

ddiff --git a/public/css/app.css b/public/css/app.css
iindex b0a7f4e..f38c7a0 100644
---- a/public/css/app.css
++++ b/public/css/app.css
@@@ -80,6 +80,6 @@ dl.facts dd { margin: 0; overflow-wrap: anywhere; }
  /* The home page's showcase sections sit inside .page, which has its own gutter. */
  .page .sc-hero, .page .sc-sec, .page .sc-cta { padding-left: 0; padding-right: 0; }
  .watch-later { max-width: 1080px; margin: 10px auto 0; }
--ul.facts { list-style: none; margin: 12px 0; padding: 0; max-width: none; display: grid; gap: 10px; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); }
++ul.facts { list-style: none; margin: 12px 0; padding: 0; max-width: none; display: grid; gap: 10px; grid-template-columns: repeat(auto-fill, minmax(min(300px, 100%), 1fr)); }
  ul.facts li { margin: 0; padding: 14px 16px; border-radius: 14px; border: 1px solid var(--border, #1f2d47); background: var(--bg-card, #131c2e); font-size: .92rem; line-height: 1.5; color: var(--text-secondary, #96a7c2); }
  ul.facts li strong { display: block; margin-bottom: 4px; color: var(--text-primary, #e6edf7); font-size: 1rem; }