:root {
  --bg: #f7f4ee;
  --bg-accent: #ece2d0;
  --panel: #fffdfa;
  --ink: #1f2228;
  --muted: #646b76;
  --line: #d9d3c8;
  --accent: #0f766e;
  --danger: #b91c1c;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: "Iowan Old Style", "Palatino Linotype", serif;
  background: radial-gradient(circle at 10% 0%, var(--bg-accent), var(--bg));
  color: var(--ink);
}
.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  padding: 1rem 1.5rem;
  border-bottom: 1px solid var(--line);
  background: #fdf8efcc;
  backdrop-filter: blur(4px);
  position: sticky;
  top: 0;
}
h1,h2,h3,h4,p { margin: 0; }
.layout { padding: 1rem; max-width: 1400px; margin: 0 auto; }
.card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 1rem;
}
.auth-card { max-width: 460px; margin: 3rem auto; }
.stack { display: grid; gap: 0.6rem; }
.row-between { display: flex; justify-content: space-between; align-items: center; gap: .75rem; }
.muted { color: var(--muted); font-size: .9rem; }
.error { color: var(--danger); min-height: 1.1rem; margin-top: .4rem; }
.hidden { display: none !important; }
.session-box { font-size: .9rem; color: var(--muted); }

.app-grid {
  display: grid;
  grid-template-columns: 280px minmax(0,1fr) 340px;
  gap: 1rem;
}
.full-row { grid-column: 1 / -1; }

input, textarea, button {
  font: inherit;
  border-radius: 8px;
}
input, textarea {
  width: 100%;
  border: 1px solid var(--line);
  padding: .55rem .65rem;
  background: #fff;
}
button {
  border: 1px solid transparent;
  background: var(--accent);
  color: #fff;
  padding: .5rem .75rem;
  cursor: pointer;
}
button:hover { filter: brightness(0.95); }
button.danger { background: var(--danger); }

.list { list-style: none; padding: 0; margin: .8rem 0 0; display: grid; gap: .55rem; }
.list li {
  border: 1px solid var(--line);
  padding: .55rem;
  border-radius: 8px;
  cursor: pointer;
}
.list li.active { border-color: var(--accent); background: #eefaf8; }

.post-card {
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: .75rem;
  background: #fff;
}
.post-title { font-size: 1.1rem; }
.meta { color: var(--muted); font-size: .85rem; margin-top: .4rem; }
.post-body { white-space: pre-wrap; margin-top: .65rem; }
.reply-box { margin-top: .9rem; border-top: 1px dashed var(--line); padding-top: .75rem; }
.reply-item {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: .45rem;
}
.reply-item p { margin-top: .35rem; white-space: pre-wrap; }
.thread {
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: .65rem;
}
.card ul { margin: .4rem 0 0; padding-left: 1.1rem; }
.card li { margin: .3rem 0; }
.bubble-ai { background: #edf7ff; border-left: 3px solid #2563eb; padding: .4rem .5rem; border-radius: 6px; }
.bubble-user { background: #f6f7f8; border-left: 3px solid #6b7280; padding: .4rem .5rem; border-radius: 6px; }

@media (max-width: 1050px) {
  .app-grid { grid-template-columns: 1fr; }
  .full-row { grid-column: auto; }
}