body {
  margin:0;
  font-family: Arial, sans-serif;
  background:#0f1724;
  color:#e6eef6;
  display:flex;
  justify-content:center;
  align-items:center;
  min-height:100vh;
}
.app {
  width:90%;
  max-width:800px;
  background:#0b1220;
  border-radius:12px;
  overflow:hidden;
  display:flex;
  flex-direction:column;
}
header {
  padding:12px 18px;
  display:flex;
  justify-content:space-between;
  align-items:center;
  background:#131a2b;
}
header h1 {margin:0;}
main {padding:12px; display:flex; flex-direction:column; gap:10px;}
.chat {
  min-height:300px;
  max-height:60vh;
  overflow-y:auto;
  display:flex;
  flex-direction:column;
  gap:8px;
}
.bubble {
  max-width:75%;
  padding:8px 12px;
  border-radius:10px;
  line-height:1.3;
}
.user {align-self:flex-end; background:#133b5c;}
.ai {align-self:flex-start; background:rgba(255,255,255,0.05);}
.controls {display:flex; gap:6px;}
.controls input {flex:1; padding:8px 10px; border-radius:8px; border:none; background:rgba(255,255,255,0.02); color:#e6eef6;}
.controls button {padding:8px 12px; border:none; border-radius:8px; background:#ff6b6b; color:#081126; cursor:pointer;}
footer {padding:8px 12px; text-align:center; font-size:12px; color:#94a3b8;}