body { font-family: Inter, system-ui, Arial, sans-serif; background:#f7fafc; color:#0f172a; }
.container{ max-width:780px; margin:36px auto; }
.card{ background:white; padding:18px; border-radius:8px; box-shadow:0 1px 4px rgba(15,23,42,0.06); margin-bottom:18px }
h1{ margin:0 0 12px }
form{ display:flex; gap:8px; align-items:center }
input[type=text], input[type=file], input#question{ flex:1; padding:8px 10px; border-radius:6px; border:1px solid #e6eef5 }
button{ padding:8px 12px; border-radius:6px; border:0; background:#0ea5a4; color:white }
.muted{ color:#64748b; margin-top:8px }
#messages{ max-height:300px; overflow:auto; padding:8px; border:1px solid #f1f5f9; background:#fff }
.message{ padding:6px 8px; margin:6px 0; border-radius:6px }
.message.user{ background:#e6fffa; align-self:flex-end }
.message.assistant{ background:#eef2ff }