body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f0f2f5;
    color: #333;
    display: flex;
    justify-content: center;
    padding: 20px;
}

.container {
    width: 600px;
    background: white;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.controls {
    margin: 20px 0;
    display: flex;
    gap: 10px;
}

.doc-picker {
    display: flex;
    flex-direction: column;
    gap: 6px;
    margin-top: 10px;
}

.doc-picker label {
    font-size: 14px;
    font-weight: 600;
    color: #444;
}

.doc-picker select {
    padding: 8px 10px;
    border: 1px solid #ccc;
    border-radius: 6px;
    font-size: 14px;
    background: #fff;
}

button {
    padding: 10px 20px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 16px;
    transition: background 0.2s;
}

#startBtn {
    background-color: #007bff;
    color: white;
}

#startBtn:disabled {
    background-color: #ccc;
}

#stopBtn {
    background-color: #dc3545;
    color: white;
}

#recordBtn {
    background-color: #17a2b8;
    color: white;
}

#stopBtn:disabled {
    background-color: #ccc;
}

.chat-window {
    height: 300px;
    overflow-y: auto;
    border: 1px solid #eee;
    padding: 10px;
    margin-bottom: 20px;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.message {
    padding: 10px;
    border-radius: 8px;
    max-width: 80%;
}

.tutor {
    background-color: #e3f2fd;
    align-self: flex-start;
}

.user {
    background-color: #f1f0f0;
    align-self: flex-end;
}

.message.live {
    opacity: 0.7;
    font-style: italic;
}

.citations-panel {
    border-top: 1px solid #eee;
    padding-top: 10px;
}

.concept-panel {
    border-top: 1px solid #eee;
    padding-top: 10px;
    margin-top: 10px;
}

#conceptCanvas {
    width: 100%;
    border: 1px solid #eee;
    border-radius: 6px;
    background: #fafafa;
}

.input-area {
    display: flex;
    gap: 10px;
    margin-bottom: 15px;
}

.input-area input {
    flex: 1;
    padding: 10px;
    border: 1px solid #ccc;
    border-radius: 4px;
    font-size: 14px;
}

.input-area input:disabled {
    background-color: #f5f5f5;
}

.input-area button {
    padding: 10px 20px;
    background-color: #28a745;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
}

.input-area button:disabled {
    background-color: #ccc;
}