/* Colorful & fun style inspired by Duolingo */
:root{
  --bg:#f7fbf9;
  --card:#ffffff;
  --accent:#00b894;
  --accent-dark:#01966f;
  --muted:#6b7280;
  --radius:16px;
  --glass: rgba(255,255,255,0.85);
}
*{box-sizing:border-box}
body{
  margin:0;
  font-family: Inter, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial;
  background: linear-gradient(135deg,#e6fff5 0%, #f0f7ff 100%);
  color:#0f172a;
  -webkit-font-smoothing:antialiased;
  -moz-osx-font-smoothing:grayscale;
  padding:24px;
}
.app{
  max-width:920px;
  margin:16px auto;
  background:var(--glass);
  border-radius:20px;
  padding:20px;
  box-shadow:0 12px 30px rgba(2,6,23,0.08);
}
.hero{
  display:flex;
  gap:16px;
  align-items:center;
}
.logo{
  font-size:28px;
  margin:0;
  color:var(--accent-dark);
}
.tag{margin:0;color:var(--muted)}
.controls{margin-top:18px;padding:12px;background:var(--card);border-radius:12px;display:flex;flex-direction:column;gap:12px}
.row{display:flex;gap:12px;align-items:center;flex-wrap:wrap}
label{font-size:14px;color:var(--muted)}
select,input[type=range]{padding:8px 10px;border-radius:8px;border:1px solid #e6eef6;background:#fff}
.primary{background:linear-gradient(180deg,var(--accent),var(--accent-dark));color:#fff;border:0;padding:10px 14px;border-radius:12px;cursor:pointer}
.secondary{background:#fff;border:1px solid #e6eef6;padding:8px 12px;border-radius:10px;cursor:pointer}
.chat{margin-top:16px}
.history{min-height:260px;max-height:420px;overflow:auto;padding:12px;background:linear-gradient(180deg,#ffffff,#f7faff);border-radius:12px;border:1px dashed rgba(0,0,0,0.04)}
.msg{display:flex;gap:12px;margin-bottom:12px;align-items:flex-start}
.msg.user .bubble{background:linear-gradient(90deg,#d7fbe9,#b8f0d9);align-self:flex-end}
.msg.ai .bubble{background:linear-gradient(90deg,#fff7d6,#fff0b3)}
.bubble{padding:10px 14px;border-radius:12px;max-width:78%;box-shadow:0 6px 18px rgba(2,6,23,0.04)}
.role{font-size:12px;color:var(--muted);margin-bottom:6px}
.foot{margin-top:14px;text-align:center;color:var(--muted)}
@media (max-width:600px){
  .app{padding:14px}
  .logo{font-size:22px}
  .history{min-height:220px}
}