Phone 320px: list grids with a 290-420px minimum column use minmax(min(N, 100%), 1fr), so a single column fits a 320px screen (#90)

ddiff --git a/public/css/pics.css b/public/css/pics.css
iindex 1407eee..4b9773c 100644
---- a/public/css/pics.css
++++ b/public/css/pics.css
@@@ -88,7 +88,7 @@
  .ovp-desc { max-width: 70ch; white-space: pre-line; overflow-wrap: anywhere; }
  .ovp-ai { max-width: 70ch; margin: 8px 0 0; color: var(--ovp-dim); overflow-wrap: anywhere; }
  .ovp-ai-label { display: inline-block; margin-right: 6px; padding: 1px 8px; border-radius: 999px; border: 1px solid color-mix(in srgb, var(--ovp-pink) 45%, var(--ovp-line-strong)); color: var(--ovp-accent-text); font-size: .74rem; font-weight: 700; vertical-align: 1px; }
--.ovp-share { margin-top: 1.6rem; display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 10px 16px; }
++.ovp-share { margin-top: 1.6rem; display: grid; grid-template-columns: repeat(auto-fit, minmax(min(300px, 100%), 1fr)); gap: 10px 16px; }
  .ovp-share h2 { grid-column: 1 / -1; margin-bottom: 0; }
  .ovp-copy { display: grid; gap: 4px; min-width: 0; }
  .ovp-copy label { font-size: .8rem; font-weight: 700; color: var(--ovp-dim); }