*{box-sizing:border-box}body{margin:0;background:#efeae2;font-family:system-ui,Arial,sans-serif}
.app{max-width:860px;margin:0 auto;height:100dvh;display:flex;flex-direction:column}

.chat{flex:1;overflow:auto;padding:16px;display:flex;flex-direction:column;gap:10px}
.bubble{max-width:80%;padding:10px 12px;border-radius:12px;position:relative}
.bubble .time{font-size:11px;color:#0008;text-align:right;margin-top:4px}
.user{align-self:flex-end;background:#dcf8c6;border-top-right-radius:4px}
.bot{align-self:flex-start;background:#fff;border-top-left-radius:4px}
.typing{width:56px;height:28px;background:#fff;border-radius:16px;display:flex;align-items:center;justify-content:center;padding:0 8px}
.dot{width:6px;height:6px;border-radius:50%;background:#888;margin:0 2px;animation:blink 1.4s infinite}
.dot:nth-child(2){animation-delay:.2s}.dot:nth-child(3){animation-delay:.4s}
@keyframes blink{0%,80%,100%{opacity:.2}40%{opacity:1}}
.composer{display:flex;gap:8px;padding:10px;background:#f0f2f5;border-top:1px solid #ddd;align-items:center}
.composer .attach{background:#fff;border:1px dashed #bbb;padding:8px;border-radius:8px;cursor:pointer}
.composer input[type=number]{width:90px}
.composer select{width:110px}
.composer button{background:#25d366;color:#fff;border:none;padding:10px 14px;border-radius:10px;font-weight:700;cursor:pointer}
.quiz-preview{background:#fff;border-radius:12px;padding:10px;border:1px solid #eee}
.quiz-preview h4{margin:6px 0}.quiz-item{margin:10px 0}.quiz-opts{margin-left:12px}
.shield{position:fixed;inset:0;background:rgba(0,0,0,.75);color:#fff;display:flex;align-items:center;justify-content:center;z-index:9999}
.shield.hidden{display:none}.shield>div{background:#1f2937;padding:24px;border-radius:12px;text-align:center}
.shield h3{margin:0 0 8px}.shield button{margin-top:10px;padding:8px 12px;border-radius:8px;border:none;cursor:pointer}
.header {
  background: #075e54;
  color: #fff;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 16px;
  font-size: 18px;
  font-weight: bold;
  position: sticky;
  top: 0;
  z-index: 10;
}

.header .logo {
  width: 40px;
  height: 40px;
  object-fit: contain;
  border-radius: 6px;
}