.ia-msg-cols{
  display:grid;
  grid-template-columns: 320px 1fr;
  min-height: 560px;
}

/* LEFT (Discord-like sidebar) */
.ia-msg-left{
  border-right: 1px solid var(--ia-line);
  background:
    linear-gradient(180deg, rgba(255,255,255,0.03), transparent 30%),
    linear-gradient(180deg, var(--ia-panel), var(--ia-bg0));
  display:flex;
  flex-direction:column;
}

.ia-msg-left-head{
  display:flex;
  align-items:center;
  justify-content:space-between;
  padding: 12px 12px;
  border-bottom: 1px solid var(--ia-line);
  background: linear-gradient(180deg, rgba(255,255,255,0.03), transparent);
}

.ia-msg-search{
  padding: 10px 12px 12px;
  border-bottom: 1px solid var(--ia-line);
}

.ia-msg-search-input{
  width:100%;
  padding: 10px 12px;
  border-radius: 12px;
  border: 1px solid var(--ia-line2);
  background: rgba(0,0,0,0.35);
  color: var(--ia-text);
  outline: none;
  transition: border-color .12s ease, box-shadow .12s ease, background .12s ease;
}
.ia-msg-search-input:focus{
  border-color: rgba(167,139,250,0.55);
  box-shadow: 0 0 0 3px rgba(124,58,237,0.18);
  background: rgba(0,0,0,0.45);
}

.ia-msg-threadlist{
  flex:1;
  overflow:auto;
  padding: 8px 6px 10px;
}

/* RIGHT (Discord-ish chat pane) */
.ia-msg-main{
  display:flex;
  flex-direction:column;
  background:
    radial-gradient(900px 480px at 70% 0%, rgba(124,58,237,0.08), transparent 60%),
    linear-gradient(180deg, var(--ia-bg2), var(--ia-bg0));
}

.ia-msg-main-head{
  padding: 12px 14px;
  border-bottom: 1px solid var(--ia-line);
  background: linear-gradient(180deg, rgba(255,255,255,0.03), transparent);
}

.ia-msg-threadname{
  font-weight: 800;
  font-size: 13px;
  letter-spacing: 0.2px;
  color: var(--ia-text);
}

.ia-msg-log{
  flex:1;
  overflow:auto;
  padding: 14px;
}

.ia-msg-composer{
  display:grid;
  grid-template-columns: 1fr auto;
  gap: 10px;
  padding: 12px 14px;
  border-top: 1px solid var(--ia-line);
  background:
    linear-gradient(180deg, rgba(0,0,0,0.25), rgba(0,0,0,0.45));
}

.ia-msg-text{
  width:100%;
  resize:none;
  border-radius: 14px;
  border: 1px solid var(--ia-line2);
  background: rgba(0,0,0,0.35);
  color: var(--ia-text);
  padding: 10px 12px;
  min-height: 44px;
  outline: none;
  transition: border-color .12s ease, box-shadow .12s ease, background .12s ease;
}
.ia-msg-text:focus{
  border-color: rgba(167,139,250,0.55);
  box-shadow: 0 0 0 3px rgba(124,58,237,0.18);
  background: rgba(0,0,0,0.45);
}

/* Mobile: single-pane routing */
.ia-msg-back{
  display:none;
  background: rgba(0,0,0,0.25);
  border: 1px solid var(--ia-line2);
  color: var(--ia-text);
  border-radius: 12px;
  padding: 6px 10px;
  cursor: pointer;
}

@media (max-width: 820px){
  .ia-msg-cols{ grid-template-columns: 1fr; min-height: 100%; height: 100%; }
  .ia-msg-shell[data-mobile-view="list"] .ia-msg-left{ display:flex; }
  .ia-msg-shell[data-mobile-view="list"] .ia-msg-main{ display:none; }
  .ia-msg-shell[data-mobile-view="chat"] .ia-msg-left{ display:none; }
  .ia-msg-shell[data-mobile-view="chat"] .ia-msg-main{ display:flex; }
  .ia-msg-back{ display:inline-flex; }
  .ia-msg-main-head{ display:flex; align-items:center; gap: 10px; }
}

/* Hard rule: back button never shows on desktop */
.ia-msg-back{ display:none !important; }
@media (max-width: 820px){ .ia-msg-back{ display:inline-flex !important; } }