:root{
  --bg:#0b0b0f;
  --panel:#11111a;
  --card:#141420;
  --line:#2a2a3a;
  --text:#ffffff;
  --muted:#a9a9c0;
  --btn:#2d6cdf;
  --btn2:#222236;
  --danger:#ffb4b4;
  --bubbleUser:#1c2a44;
  --bubbleBot:#141420;
}

*{box-sizing:border-box}
html,body{height:100%}
body{margin:0;background:var(--bg);color:var(--text);font-family:system-ui,-apple-system,Segoe UI,Roboto,Arial}
a{color:var(--text);text-decoration:none}
.page{height:100%;display:flex}
.card{padding:18px;border:1px solid var(--line);border-radius:14px;background:var(--card)}

.sidebar{
  width:280px;min-width:260px;max-width:320px;
  background:var(--panel);
  border-right:1px solid var(--line);
  display:flex;flex-direction:column;
}
.sideTop{padding:14px;border-bottom:1px solid var(--line);display:flex;gap:10px;align-items:center;justify-content:space-between}
.brand{font-weight:900}
.newBtn{background:var(--btn);border:none;color:#fff;padding:8px 10px;border-radius:10px;cursor:pointer;font-weight:700}
.chatList{padding:10px;overflow:auto;flex:1}
.chatItem{
  padding:10px;border-radius:10px;border:1px solid transparent;
  cursor:pointer;margin-bottom:8px;
  background:transparent;
}
.chatItem:hover{border-color:var(--line);background:#0e0e16}
.chatItem.active{background:#0e0e16;border-color:var(--line)}
.chatTitle{font-weight:700;font-size:14px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.chatMeta{font-size:12px;color:var(--muted);margin-top:4px}
.sideBottom{padding:12px;border-top:1px solid var(--line);display:flex;gap:10px;align-items:center;justify-content:space-between}

.main{flex:1;display:flex;flex-direction:column;min-width:0}
.topbar{padding:14px;border-bottom:1px solid var(--line);display:flex;justify-content:space-between;align-items:center;gap:12px}
.badge{padding:4px 8px;border-radius:999px;border:1px solid var(--line);font-size:12px;color:var(--muted)}
.btn2{background:var(--btn2);border:1px solid var(--line);color:#fff;padding:8px 10px;border-radius:10px;cursor:pointer}
.btn{background:var(--btn);border:none;color:#fff;padding:10px 14px;border-radius:12px;cursor:pointer;font-weight:800}

.thread{flex:1;overflow:auto;padding:18px;display:flex;flex-direction:column;gap:12px}
.msgRow{display:flex;gap:10px}
.msgRow.user{justify-content:flex-end}
.bubble{
  max-width:900px;width:fit-content;
  padding:12px 14px;border-radius:14px;border:1px solid var(--line);
  white-space:pre-wrap;line-height:1.45;
}
.user .bubble{background:var(--bubbleUser)}
.assistant .bubble{background:var(--bubbleBot)}
.avatar{
  width:34px;height:34px;border-radius:10px;border:1px solid var(--line);
  display:flex;align-items:center;justify-content:center;
  color:var(--muted);font-weight:800;font-size:12px;flex:0 0 auto;
  background:#0e0e16;
}
.user .avatar{display:none}
.assistant .avatar{display:flex}

.composer{
  border-top:1px solid var(--line);
  padding:12px;display:flex;gap:10px;align-items:flex-end;
}
.textarea{
  flex:1;min-height:44px;max-height:180px;
  padding:10px 12px;border-radius:12px;border:1px solid var(--line);
  background:#0b0b0f;color:#fff;resize:none;outline:none;
}
.sendBtn{background:var(--btn);border:none;color:#fff;padding:10px 14px;border-radius:12px;cursor:pointer;font-weight:800}
.muted{color:var(--muted)}
.alert{padding:10px 12px;border-radius:12px;border:1px solid var(--line);margin-top:10px}
.alert.bad{border-color:rgba(255,180,180,.35);color:var(--danger)}
.input{width:100%;padding:10px;border-radius:12px;border:1px solid var(--line);background:var(--bg);color:#fff;margin:6px 0 12px 0}
label{display:block;color:var(--muted);font-size:12px;margin-top:8px}