:root {
    --bg: #eef1f4; --col: #e1e6eb; --card: #ffffff; --ink: #1c2530; --muted: #667585;
    --line: #cfd7df; --accent: #1f6fd1; --danger: #b3261e; --ok: #1d7a46;
    color-scheme: light dark;
  }
  @media (prefers-color-scheme: dark) {
    :root { --bg:#11161c; --col:#1a222b; --card:#232d38; --ink:#e7ecf1; --muted:#93a3b3;
            --line:#33414f; --accent:#6aa7f5; --danger:#f2918b; --ok:#6fd09a; }
  }
  * { box-sizing: border-box; }
  html, body { height: 100%; margin: 0; }
  body { font: 15px/1.4 system-ui, -apple-system, "Segoe UI", sans-serif; background: var(--bg);
         color: var(--ink); display: flex; flex-direction: column; }
  header { display: flex; align-items: center; gap: 10px; padding: 12px 16px; flex-wrap: wrap; }
  header h1 { font-size: 18px; margin: 0 6px 0 0; font-weight: 650; letter-spacing: -.01em; }
  header .spacer { flex: 1; }
  #status { color: var(--muted); font-size: 13px; }
  button, select { font: inherit; padding: 6px 12px; border-radius: 6px; border: 1px solid var(--line);
           background: var(--card); color: var(--ink); }
  button { cursor: pointer; }
  button:hover { border-color: var(--accent); }
  button:focus-visible, select:focus-visible, .card:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
  button.primary { background: var(--accent); border-color: var(--accent); color: #fff; }
  button.danger { color: var(--danger); }
  button:disabled { opacity: .6; cursor: default; }
  #error { margin: 0 16px 8px; padding: 10px 12px; border-radius: 6px; color: var(--danger);
           border: 1px solid var(--danger); display: none; }
  #board { flex: 1; min-height: 0; display: flex; gap: 12px; padding: 0 16px 16px; overflow-x: auto; }
  .col { flex: 0 0 280px; display: flex; flex-direction: column; background: var(--col);
         border-radius: 8px; max-height: 100%; }
  .col h2 { margin: 0; padding: 12px 12px 8px; font-size: 14px; font-weight: 650; display: flex; gap: 8px; }
  .col h2 .n { color: var(--muted); font-weight: 400; }
  .list { flex: 1; overflow-y: auto; padding: 4px 8px 8px; min-height: 60px; }
  .card { background: var(--card); border: 1px solid var(--line); border-radius: 6px;
          padding: 9px 10px; margin-bottom: 8px; cursor: grab; }
  .card .subj { font-weight: 450; overflow-wrap: anywhere; display: -webkit-box;
                -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
  .card.unseen .subj { font-weight: 700; }
  .card.unseen { border-left: 3px solid var(--accent); }
  .card .meta { margin-top: 4px; font-size: 12.5px; color: var(--muted); display: flex;
                justify-content: space-between; gap: 8px; }
  .card .meta .who { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
  .card .meta .when { white-space: nowrap; }
  .ghost { opacity: .4; }
  .emptystate { margin: auto; text-align: center; color: var(--muted); display: flex; flex-direction: column; gap: 12px; align-items: center; }
  dialog { width: min(680px, 94vw); max-height: 92vh; padding: 0; border: 1px solid var(--line);
           border-radius: 8px; background: var(--card); color: var(--ink); }
  dialog::backdrop { background: rgba(0,0,0,.45); }
  dialog .inner { display: flex; flex-direction: column; gap: 10px; padding: 16px; max-height: 92vh; }
  dialog h2 { margin: 0; font-size: 17px; overflow-wrap: anywhere; }
  dialog .who { color: var(--muted); font-size: 13px; }
  dialog .text { white-space: pre-wrap; overflow-wrap: anywhere; overflow-y: auto; min-height: 120px;
                 padding: 10px; background: var(--bg); border-radius: 6px; font-size: 14px; }
  dialog .actions { display: flex; gap: 8px; justify-content: flex-end; flex-wrap: wrap; }
  dialog .actions .spacer { flex: 1; }
  dialog label { display: flex; flex-direction: column; gap: 3px; font-size: 13px; color: var(--muted); }
  dialog label.check { flex-direction: row; align-items: center; gap: 8px; }
  dialog input[type=text], dialog input[type=password], dialog input[type=number], dialog textarea, dialog select {
           font: inherit; padding: 7px 9px; border-radius: 6px; color: var(--ink);
           border: 1px solid var(--line); background: var(--card); width: 100%; }
  dialog textarea { min-height: 240px; resize: vertical; }
  dialog .err { color: var(--danger); font-size: 13px; margin: 0; min-height: 1em; }
  .scroll { overflow-y: auto; display: flex; flex-direction: column; gap: 14px; padding-right: 2px; }
  fieldset { border: 1px solid var(--line); border-radius: 6px; margin: 0; padding: 10px 12px 12px;
             display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
  fieldset legend { padding: 0 6px; font-weight: 650; font-size: 13px; }
  fieldset .wide { grid-column: 1 / -1; }
  .res { font-size: 13px; margin: 0; }
  .res .ok { color: var(--ok); } .res .bad { color: var(--danger); } .res .na { color: var(--muted); }
  .hint { font-size: 12.5px; color: var(--muted); margin: 0; }
  @media (max-width: 640px) { .col { flex-basis: 85vw; } fieldset { grid-template-columns: 1fr; } }
  /* login page */
  body.login { align-items: center; justify-content: center; padding: 16px; }
  .loginbox { width: min(360px, 100%); background: var(--card); border: 1px solid var(--line);
              border-radius: 8px; padding: 20px; display: flex; flex-direction: column; gap: 12px; }
  .loginbox h1 { margin: 0 0 4px; font-size: 20px; }
  .loginbox label { display: flex; flex-direction: column; gap: 3px; font-size: 13px; color: var(--muted); }
  .loginbox input { font: inherit; padding: 8px 10px; border-radius: 6px; color: var(--ink);
                    border: 1px solid var(--line); background: var(--bg); }
  .loginbox .err { color: var(--danger); margin: 0; font-size: 14px; }
  .loginbox button { padding: 8px 12px; }
  #whoami { color: var(--muted); font-size: 13px; }