* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: #f5f5f5;
    color: #333;
}

.container {
    display: flex;
    height: 100vh;
}

.sidebar {
    width: 300px;
    background: #fff;
    border-right: 1px solid #e0e0e0;
    display: flex;
    flex-direction: column;
}

.sidebar-header {
    padding: 20px;
    border-bottom: 1px solid #e0e0e0;
}

.sidebar-header h2 {
    font-size: 18px;
    font-weight: 600;
}

.upload-section {
    padding: 20px;
    border-bottom: 1px solid #e0e0e0;
}

.btn-upload {
    width: 100%;
    padding: 12px;
    background: #007bff;
    color: white;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: background 0.2s;
}

.btn-upload:hover {
    background: #0056b3;
}

.document-list {
    flex: 1;
    overflow-y: auto;
    padding: 10px;
}

.document-item {
    padding: 12px;
    margin-bottom: 8px;
    background: #f8f9fa;
    border-radius: 6px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.document-item:hover {
    background: #e9ecef;
}

.document-name {
    font-size: 14px;
    flex: 1;
}

.btn-delete {
    padding: 6px 12px;
    background: #dc3545;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 12px;
}

.btn-delete:hover {
    background: #c82333;
}

.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    background: #fff;
}

.chat-header {
    padding: 20px;
    border-bottom: 1px solid #e0e0e0;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.chat-header h1 {
    font-size: 24px;
    font-weight: 600;
}

.toggle-rag {
    display: flex;
    align-items: center;
    gap: 8px;
}

.toggle-rag label {
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
}

.chat-messages {
    flex: 1;
    overflow-y: auto;
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.message {
    max-width: 70%;
    padding: 12px 16px;
    border-radius: 12px;
    line-height: 1.5;
    font-size: 14px;
}

.message.user {
    align-self: flex-end;
    background: #007bff;
    color: white;
}

.message.assistant {
    align-self: flex-start;
    background: #f1f3f4;
    color: #333;
}

.message.loading {
    align-self: flex-start;
    background: #f1f3f4;
    color: #666;
    font-style: italic;
}

.chat-input {
    padding: 20px;
    border-top: 1px solid #e0e0e0;
    display: flex;
    gap: 12px;
}

#messageInput {
    flex: 1;
    padding: 12px 16px;
    border: 1px solid #e0e0e0;
    border-radius: 24px;
    font-size: 14px;
    outline: none;
}

#messageInput:focus {
    border-color: #007bff;
}

.btn-send {
    padding: 12px 24px;
    background: #007bff;
    color: white;
    border: none;
    border-radius: 24px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: background 0.2s;
}

.btn-send:hover {
    background: #0056b3;
}

.btn-send:disabled {
    background: #ccc;
    cursor: not-allowed;
}

::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: #f1f1f1;
}

::-webkit-scrollbar-thumb {
    background: #888;
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: #555;
}