body {
  margin: 0;
  font-family: Arial, sans-serif;
}

#main {
  display: flex;
  flex-direction: column;
  height: 100vh;
}

#toolbar {
  background: #2c3e50;
  padding: 10px;
}

canvas {
  flex: 1;
  border: 2px solid #000;
}

/* Chat */
#chatContainer {
  height: 220px;
  display: flex;
  flex-direction: column;
  background: #f4f4f4;
  border-top: 2px solid #ccc;
}

#chatBox {
  flex: 1;
  overflow-y: auto;
  padding: 10px;
}

/* Message bubble */
.message {
  max-width: 70%;
  padding: 8px 12px;
  margin: 5px 0;
  border-radius: 10px;
  font-size: 14px;
}

.teacher {
  background: #d1ecf1;
  align-self: flex-end;
}

.student {
  background: #ffffff;
  align-self: flex-start;
}

.name {
  font-size: 11px;
  color: #555;
  margin-bottom: 2px;
}

/* Input */
#chatInput {
  display: flex;
  border-top: 1px solid #ccc;
}

#chatInput input {
  flex: 1;
  padding: 10px;
  border: none;
}

#chatInput button {
  padding: 10px;
  background: #2c3e50;
  color: white;
  border: none;
}