/* ============================================================================
   App shell: left sidebar (nav) + main workspace. Right panel is in sidebar.css.
   ========================================================================== */

.app-container {
  display: flex;
  width: 100vw;
  height: 100vh;
  background: var(--bg-main);
  position: relative;
}

.app-container.drag-active::after {
  content: 'Drop files to attach';
  position: fixed;
  inset: 0;
  background: rgba(109, 167, 236, 0.08);
  border: 2px dashed var(--accent);
  display: grid;
  place-items: center;
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--accent);
  z-index: 1000;
  pointer-events: none;
}

/* ---------- Left sidebar ---------- */
.sidebar {
  width: var(--sidebar-width);
  background: var(--bg-sidebar);
  display: flex;
  flex-direction: column;
  padding: 0.85rem 0.6rem;
  gap: 0.3rem;
  flex-shrink: 0;
  min-width: 0;
}

.brand {
  display: flex;
  align-items: center;
  padding: 0.4rem 0.55rem 0.6rem;
}

.brand-name {
  font-weight: 600;
  font-size: 14px;
  letter-spacing: -0.005em;
  color: var(--text-primary);
}

.new-chat-btn {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.55rem 0.7rem;
  border-radius: var(--radius-sm);
  font-size: 13px;
  color: var(--text-primary);
  background: var(--bg-surface);
  transition: background .12s;
}
.new-chat-btn:hover { background: var(--bg-hover); }

.convo-heading {
  font-size: 10.5px;
  font-weight: 600;
  color: var(--text-faint);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: 0.85rem 0.65rem 0.35rem;
}

.convo-list {
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 1px;
  padding: 0 0.15rem;
}

.convo-item {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.42rem 0.6rem;
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  font-size: 12.5px;
  min-width: 0;
  transition: background .1s, color .1s;
}
.convo-item:hover,
.convo-item.active { background: var(--bg-surface); color: var(--text-primary); }

.convo-title {
  flex: 1;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.convo-del {
  opacity: 0;
  width: 14px;
  height: 14px;
  color: var(--text-faint);
  transition: opacity .12s, color .12s;
}
.convo-item:hover .convo-del { opacity: 1; }
.convo-del:hover { color: var(--danger); }

.convo-empty {
  padding: 0.7rem 0.65rem;
  font-size: 12px;
  color: var(--text-faint);
}

.sidebar-spacer { flex: 1; }

.sidebar-btn {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 0.65rem;
  border-radius: var(--radius-sm);
  font-size: 12.5px;
  color: var(--text-muted);
  transition: background .12s, color .12s;
}
.sidebar-btn:hover { background: var(--bg-surface); color: var(--text-primary); }

/* ---------- Main workspace ---------- */
.main-workspace {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  background: var(--bg-main);
  overflow: hidden;
}