:root {
  --bg: #f7f7fb; --panel: #ffffff; --text: #1d1d27; --muted: #6b6b80; --border: #e3e3ee;
  --accent: #7c3aed; --accent-text: #fff; --user: #ede9fe; --danger: #dc2626; --ok: #16a34a;
  --code: #f1f1f6; --radius: 12px;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #14141c; --panel: #1c1c27; --text: #ececf3; --muted: #9a9ab0; --border: #2d2d3c;
    --user: #2e2547; --code: #26263a; }
}
* { box-sizing: border-box; }
html, body { height: 100%; margin: 0; background: var(--bg); color: var(--text); }
.hidden { display: none !important; }
.muted { color: var(--muted); font-size: .9rem; }
.error { color: var(--danger); min-height: 1.2em; }

.btn { border: 1px solid var(--border); background: var(--panel); color: var(--text); border-radius: 8px;
  padding: .55rem .9rem; font: inherit; cursor: pointer; }
.btn:disabled { opacity: .5; cursor: not-allowed; }
.btn--primary { background: var(--accent); color: var(--accent-text); border-color: var(--accent); }
.btn--danger { background: var(--danger); color: #fff; border-color: var(--danger); }
.btn--ok { background: var(--ok); color: #fff; border-color: var(--ok); }
.btn--ghost { background: transparent; }
.btn--small { padding: .3rem .6rem; font-size: .85rem; }

.login { display: grid; place-items: center; height: 100%; padding: 1rem; }
.login__card { background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 2rem; width: min(360px, 100%); display: grid; gap: .8rem; }
.login__card h1 { margin: 0; }
.login__card label { display: grid; gap: .3rem; font-size: .9rem; }
input, textarea { font: inherit; color: var(--text); background: var(--bg); border: 1px solid var(--border);
  border-radius: 8px; padding: .55rem .7rem; }

.app { display: grid; grid-template-columns: 270px 1fr; height: 100%; }
.sidebar { background: var(--panel); border-right: 1px solid var(--border); display: flex; flex-direction: column; min-height: 0; }
.sidebar__head, .sidebar__foot { display: flex; align-items: center; justify-content: space-between; gap: .5rem; padding: .8rem; }
.sidebar__foot { border-top: 1px solid var(--border); }
.brand { font-weight: 700; }
.sessions { flex: 1; overflow-y: auto; padding: 0 .5rem; }
.session { display: flex; align-items: center; gap: .3rem; border-radius: 8px; }
.session:hover, .session--active { background: var(--user); }
.session__open { flex: 1; text-align: left; background: none; border: 0; color: var(--text); padding: .55rem .6rem;
  font: inherit; cursor: pointer; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.session__del { background: none; border: 0; color: var(--muted); cursor: pointer; padding: .3rem .5rem; }

.chat { display: flex; flex-direction: column; min-height: 0; height: 100%; }
.chat__head { display: flex; align-items: center; gap: .7rem; padding: .7rem 1rem; border-bottom: 1px solid var(--border); background: var(--panel); }
.chat__head h2 { margin: 0; font-size: 1.05rem; flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.status { font-size: .8rem; color: var(--muted); }
.status--ok { color: var(--ok); }
.status--bad { color: var(--danger); }

.messages { flex: 1; overflow-y: auto; padding: 1rem; display: flex; flex-direction: column; gap: .8rem; }
.msg { max-width: min(760px, 92%); padding: .7rem .9rem; border-radius: var(--radius); line-height: 1.5; overflow-wrap: anywhere; }
.msg--user { align-self: flex-end; background: var(--user); white-space: pre-wrap; }
.msg--assistant { align-self: flex-start; background: var(--panel); border: 1px solid var(--border); }
.msg--assistant > :first-child { margin-top: 0; }
.msg--assistant > :last-child { margin-bottom: 0; }
.msg pre { background: var(--code); padding: .6rem; border-radius: 8px; overflow-x: auto; }
.msg code { background: var(--code); padding: .1rem .3rem; border-radius: 4px; font-size: .9em; }
.msg pre code { background: none; padding: 0; }
.msg blockquote { border-left: 3px solid var(--border); margin: .5rem 0; padding-left: .8rem; color: var(--muted); }
.tool { font-size: .8rem; color: var(--muted); margin: .3rem 0; }
.part-error { color: var(--danger); }
.welcome { color: var(--muted); text-align: center; margin: auto; max-width: 420px; }

.activity { padding: 0 1rem; min-height: 1.4rem; font-size: .85rem; color: var(--muted); }
.activity:not(:empty)::before { content: "⏳ "; }
.error-bar { margin: 0 1rem .4rem; padding: .5rem .8rem; border-radius: 8px; background: color-mix(in srgb, var(--danger) 15%, transparent);
  color: var(--danger); display: flex; justify-content: space-between; align-items: center; gap: .5rem; }
.hitl { margin: 0 1rem .6rem; padding: .8rem; border: 2px solid var(--accent); border-radius: var(--radius); background: var(--panel); display: grid; gap: .5rem; }
.hitl pre { background: var(--code); padding: .5rem; border-radius: 8px; overflow-x: auto; margin: 0; white-space: pre-wrap; }
.row { display: flex; gap: .5rem; flex-wrap: wrap; }
.row input { flex: 1; }
.followups { display: flex; gap: .5rem; flex-wrap: wrap; padding: 0 1rem .6rem; }
.chip { border: 1px solid var(--accent); color: var(--accent); background: transparent; border-radius: 999px; padding: .35rem .8rem; cursor: pointer; font: inherit; font-size: .9rem; }

.composer { display: flex; gap: .5rem; padding: .7rem 1rem 1rem; border-top: 1px solid var(--border); background: var(--panel); }
.composer textarea { flex: 1; resize: none; max-height: 40vh; }
.only-mobile { display: none; }

@media (max-width: 760px) {
  .app { grid-template-columns: 1fr; }
  .sidebar { position: fixed; inset: 0 25% 0 0; z-index: 10; transform: translateX(-100%); transition: transform .2s; }
  .sidebar--open { transform: none; box-shadow: 0 0 40px rgba(0,0,0,.3); }
  .only-mobile { display: inline-block; }
}