:root{
  --bg:#ffffff;
  --ink:#1f2937;
  --muted:#6b7280;
  --line:#e5e7eb;
  --accent:#2563eb;
  --accent-ink:#ffffff;
  --card:#f9fafb;
  --good:#16a34a;
  --warn:#f59e0b;
}
@media (prefers-color-scheme: dark){
  :root{ --bg:#0b0f14; --ink:#e5e7eb; --muted:#94a3b8; --line:#263244; --accent:#3b82f6; --accent-ink:#0b0f14; --card:#121823; }
}
.trustbox-form, .trustbox-success, .trustbox-thread-public{ background:var(--bg); color:var(--ink); font: 16px/1.55 system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif; }
.trustbox-form .note{color:var(--muted); font-size:.95rem}
.trustbox-form input[type="text"], .trustbox-form input[type="email"], .trustbox-form textarea{
  width:100%; max-width:720px; padding:12px 14px; border:1px solid var(--line); border-radius:10px; background:#fff; color:#111827;
}
@media (prefers-color-scheme: dark){
  .trustbox-form input[type="text"], .trustbox-form input[type="email"], .trustbox-form textarea{ background:#0f1622; color:var(--ink); border-color:var(--line); }
}
.trustbox-form input:focus, .trustbox-form textarea:focus{ outline:2px solid transparent; box-shadow:0 0 0 3px rgba(37,99,235,.35); border-color:var(--accent); }
.trustbox-form button{ display:inline-flex; align-items:center; gap:.5rem; background:var(--accent); color:var(--accent-ink); border:0; border-radius:999px; padding:10px 18px; font-weight:600; cursor:pointer; }
.trustbox-form button:hover{ filter:brightness(1.08) } .trustbox-form button:active{ transform:translateY(1px) }
.trustbox-success{ margin:18px 0; padding:18px; border:1px dashed var(--line); border-radius:14px; background:var(--card); }
.trustbox-success h3{ margin:0 0 8px }
.trustbox-success .trustbox-code{ font-size:2rem; letter-spacing:.18em; font-weight:800; padding:10px 14px; border:1px solid var(--line); display:inline-block; border-radius:12px; background:#fff; color:#111827; }
@media (prefers-color-scheme: dark){ .trustbox-success .trustbox-code{ background:#0f1622; color:var(--ink) } }
.trustbox-success .actions{ margin-top:10px } .trustbox-success .copy{ background:transparent; border:1px solid var(--line); border-radius:999px; padding:8px 14px; cursor:pointer; }
.trustbox-thread-public .msg{ border:1px solid var(--line); padding:14px 16px; margin:12px 0; border-radius:12px; background:#fff; }
@media (prefers-color-scheme: dark){ .trustbox-thread-public .msg{ background:#0f1622 } }
.trustbox-thread-public .msg .badge{ display:inline-block; font-size:.8rem; color:#fff; background:#9ca3af; border-radius:999px; padding:3px 8px; margin-bottom:8px; }
.trustbox-thread-public .msg-student{ border-left:4px solid var(--warn) } .trustbox-thread-public .msg-student .badge{ background:var(--warn) }
.trustbox-thread-public .msg-teacher{ border-left:4px solid var(--good); background:var(--card) } .trustbox-thread-public .msg-teacher .badge{ background:var(--good) }
.trustbox-thread-public .meta{ color:var(--muted); font-size:.85rem; margin-top:6px }
.trustbox-thread-public textarea{width:100%; max-width:720px; padding:12px 14px; border:1px solid var(--line); border-radius:10px;}