/* ── Sidebar ── */
.sidebar {
  width: 256px; min-width: 256px;
  background: var(--surface); border-right: 1px solid var(--b1);
  display: flex; flex-direction: column;
  transition: width .22s, min-width .22s; overflow: hidden;
}
.sidebar.collapsed { width: 0; min-width: 0; }

.sb-hdr {
  padding: 15px 13px 12px; border-bottom: 1px solid var(--b1);
  display: flex; align-items: center; gap: 9px;
}
.logo {
  width: 27px; height: 27px; background: var(--ac);
  border-radius: 7px; display: grid; place-items: center; flex-shrink: 0;
}
.logo svg { width: 14px; height: 14px; }
.logo-t { font-size: 13px; font-weight: 600; line-height: 1.2; }
.logo-s { font-size: 10px; color: var(--t3); }

.new-btn {
  margin: 7px 9px;
  padding: 7px 11px;
  background: var(--acbg); border: 1px solid rgba(59,124,247,.2); color: var(--ac);
  border-radius: var(--r); font-family: var(--sans); font-size: 12px; font-weight: 500;
  cursor: pointer; display: flex; align-items: center; gap: 6px; transition: .15s;
}
.new-btn:hover { background: rgba(59,124,247,.15); border-color: rgba(59,124,247,.4); }

.sec-label {
  padding: 9px 11px 3px;
  font-size: 10px; font-weight: 600; letter-spacing: .08em;
  text-transform: uppercase; color: var(--t3);
}

.chat-list { flex: 1; overflow-y: auto; padding: 2px 6px; }
.chat-item {
  padding: 7px 9px; border-radius: 7px; cursor: pointer;
  font-size: 13px; color: var(--t2);
  display: flex; align-items: center; gap: 6px;
  transition: .12s; white-space: nowrap; overflow: hidden;
}
.chat-item:hover, .chat-item.active { background: var(--panel); color: var(--t1); }
.chat-item svg { opacity: .4; flex-shrink: 0; }
.ci-label { overflow: hidden; text-overflow: ellipsis; flex: 1; }
.stage-pill {
  margin-left: auto; padding: 2px 6px; border-radius: 20px;
  font-size: 10px; font-family: var(--mono);
  background: var(--acbg); color: var(--ac); flex-shrink: 0;
}

.sb-foot { padding: 9px; border-top: 1px solid var(--b1); }
.kb-open-btn {
  width: 100%; padding: 7px 11px;
  background: transparent; border: 1px solid var(--b2); color: var(--t2);
  border-radius: var(--r); font-family: var(--sans); font-size: 12px;
  cursor: pointer; display: flex; align-items: center; gap: 7px; transition: .15s;
}
.kb-open-btn:hover { background: var(--panel); border-color: var(--ac); color: var(--t1); }

/* ── Main ── */
.main { flex: 1; display: flex; flex-direction: column; min-width: 0; }

.topbar {
  height: 50px; border-bottom: 1px solid var(--b1);
  display: flex; align-items: center; padding: 0 13px; gap: 9px;
  background: var(--surface); flex-shrink: 0;
}
.tb-toggle {
  width: 30px; height: 30px; background: transparent; border: none;
  color: var(--t2); cursor: pointer; border-radius: 6px;
  display: grid; place-items: center; transition: .15s;
}
.tb-toggle:hover { background: var(--panel); color: var(--t1); }
.tb-title { flex: 1; font-size: 13px; font-weight: 500; }
.tb-title span { color: var(--t3); font-weight: 400; }

.provider-sel {
  padding: 4px 8px; background: var(--panel); border: 1px solid var(--b2);
  color: var(--t1); border-radius: 7px; font-family: var(--sans); font-size: 12px;
  cursor: pointer; outline: none; transition: .15s;
}
.provider-sel:focus { border-color: var(--ac); }

.model-tag {
  padding: 3px 9px;
  background: var(--grbg); border: 1px solid rgba(34,197,94,.2); color: var(--gr);
  border-radius: 20px; font-size: 11px; font-family: var(--mono); white-space: nowrap;
}