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

:root {
    --primary-color: #2563eb;
    --primary-dark: #1e40af;
    --success-color: #10b981;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    --bg-primary: #f8fafc;
    --bg-secondary: #ffffff;
    --bg-chat: #f1f5f9;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: var(--text-primary);
}

.container {
    max-width: 1600px;
    margin: 0 auto;
    padding: 20px;
    height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header */
.header {
    background: var(--bg-secondary);
    border-radius: 12px;
    padding: 20px 30px;
    margin-bottom: 20px;
    box-shadow: var(--shadow-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.header-right {
    display: flex;
    align-items: center;
    gap: 20px;
}

.user-info {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px 16px;
    background: var(--bg-primary);
    border-radius: 20px;
    color: var(--text-primary);
    font-size: 14px;
}

.user-info i {
    font-size: 18px;
    color: var(--primary-color);
}

.logout-btn {
    background: none;
    border: none;
    color: var(--danger-color);
    cursor: pointer;
    padding: 4px 8px;
    border-radius: 4px;
    transition: background-color 0.2s;
}

.logout-btn:hover {
    background: rgba(239, 68, 68, 0.1);
}

.header-content h1 {
    color: var(--primary-color);
    font-size: 28px;
    margin-bottom: 5px;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 14px;
}

.system-status {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 16px;
    background: var(--bg-primary);
    border-radius: 20px;
}

.status-indicator {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--warning-color);
    animation: pulse 2s infinite;
}

.status-indicator.healthy {
    background: var(--success-color);
    animation: none;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

/* Main Content */
.main-content {
    display: grid;
    grid-template-columns: 350px 1fr;
    gap: 20px;
    flex: 1;
    overflow: hidden;
}

/* Sidebar */
.sidebar {
    background: var(--bg-secondary);
    border-radius: 12px;
    padding: 20px;
    box-shadow: var(--shadow-md);
    display: flex;
    flex-direction: column;
    gap: 20px;
    overflow-y: auto;
}

.sidebar h3 {
    font-size: 16px;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.upload-area {
    border: 2px dashed var(--border-color);
    border-radius: 8px;
    padding: 30px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s;
    margin-bottom: 12px;
}

.upload-area:hover {
    border-color: var(--primary-color);
    background: var(--bg-primary);
}

.upload-area.dragover {
    border-color: var(--primary-color);
    background: #dbeafe;
}

.upload-area i {
    font-size: 48px;
    color: var(--text-secondary);
    margin-bottom: 12px;
}

.upload-area p {
    color: var(--text-primary);
    margin-bottom: 8px;
}

.supported-formats {
    font-size: 12px;
    color: var(--text-secondary);
}

.btn-primary, .btn-secondary, .btn-icon {
    padding: 10px 20px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: all 0.3s;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
    width: 100%;
}

.btn-primary:hover {
    background: var(--primary-dark);
}

.btn-secondary {
    background: var(--bg-primary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    width: 100%;
}

.btn-secondary:hover {
    background: var(--border-color);
}

.btn-icon {
    padding: 8px;
    background: transparent;
    color: var(--text-secondary);
}

.btn-icon:hover {
    background: var(--bg-primary);
}

/* Documents List */
.documents-section {
    flex: 1;
    display: flex;
    flex-direction: column;
}

.documents-list {
    flex: 1;
    overflow-y: auto;
    margin-bottom: 12px;
}

.empty-state {
    text-align: center;
    padding: 40px 20px;
    color: var(--text-secondary);
}

.empty-state i {
    font-size: 48px;
    margin-bottom: 12px;
    opacity: 0.5;
}

.document-item {
    background: var(--bg-primary);
    border-radius: 8px;
    padding: 12px;
    margin-bottom: 8px;
    display: flex;
    align-items: start;
    gap: 12px;
    position: relative;
    transition: all 0.3s;
}

.document-item:hover {
    background: var(--border-color);
}

.document-item:hover .btn-delete-doc {
    opacity: 1;
}

.document-icon {
    font-size: 24px;
    color: var(--primary-color);
}

.document-info {
    flex: 1;
}

.document-name {
    font-weight: 500;
    font-size: 14px;
    margin-bottom: 4px;
}

.document-meta {
    font-size: 12px;
    color: var(--text-secondary);
}

.btn-delete-doc {
    background: transparent;
    border: none;
    color: var(--danger-color);
    cursor: pointer;
    padding: 8px;
    border-radius: 6px;
    opacity: 0;
    transition: all 0.3s;
    display: flex;
    align-items: center;
    justify-content: center;
}

.btn-delete-doc:hover {
    background: rgba(239, 68, 68, 0.1);
}

.btn-delete-doc:active {
    transform: scale(0.95);
}

.collection-info {
    padding: 12px;
    background: var(--bg-primary);
    border-radius: 8px;
    font-size: 12px;
    color: var(--text-secondary);
}

/* Chat Area */
.chat-area {
    background: var(--bg-secondary);
    border-radius: 12px;
    box-shadow: var(--shadow-md);
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

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

.chat-header h2 {
    font-size: 18px;
    color: var(--text-primary);
}

.header-controls {
    display: flex;
    align-items: center;
    gap: 16px;
}

.model-selector {
    display: flex;
    align-items: center;
    gap: 8px;
}

.model-selector label {
    font-size: 14px;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 6px;
}

.model-select {
    padding: 8px 12px;
    border: 2px solid var(--border-color);
    border-radius: 6px;
    background: var(--bg-secondary);
    color: var(--text-primary);
    font-size: 14px;
    cursor: pointer;
    min-width: 180px;
    transition: all 0.3s;
}

.model-select:hover {
    border-color: var(--primary-color);
}

.model-select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.messages-container {
    flex: 1;
    overflow-y: auto;
    padding: 20px;
    background: var(--bg-chat);
}

.welcome-message {
    text-align: center;
    padding: 60px 20px;
    max-width: 600px;
    margin: 0 auto;
}

.welcome-icon {
    font-size: 64px;
    color: var(--primary-color);
    margin-bottom: 20px;
}

.welcome-message h3 {
    color: var(--text-primary);
    margin-bottom: 12px;
}

.welcome-message > p {
    color: var(--text-secondary);
    margin-bottom: 24px;
}

.example-questions {
    background: var(--bg-secondary);
    border-radius: 8px;
    padding: 20px;
    text-align: left;
}

.example-questions h4 {
    margin-bottom: 12px;
    font-size: 14px;
}

.example-questions ul {
    list-style: none;
}

.example-questions li {
    padding: 8px 0;
    color: var(--text-secondary);
    font-size: 14px;
}

.example-questions li::before {
    content: "💬 ";
    margin-right: 8px;
}

.message {
    margin-bottom: 16px;
    display: flex;
    gap: 12px;
    animation: fadeIn 0.3s;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.message-avatar {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.message.user .message-avatar {
    background: var(--primary-color);
    color: white;
}

.message.bot .message-avatar {
    background: var(--success-color);
    color: white;
}

.message-content {
    flex: 1;
    max-width: 70%;
}

.message.user .message-content {
    margin-left: auto;
    margin-right: 0;
}

.message-bubble {
    padding: 12px 16px;
    border-radius: 12px;
    line-height: 1.5;
}

.message.user .message-bubble {
    background: var(--primary-color);
    color: white;
    border-bottom-right-radius: 4px;
}

.message.bot .message-bubble {
    background: var(--bg-secondary);
    color: var(--text-primary);
    border-bottom-left-radius: 4px;
}

.message-time {
    font-size: 11px;
    color: var(--text-secondary);
    margin-top: 4px;
}

.message-sources {
    margin-top: 12px;
    padding: 12px;
    background: var(--bg-primary);
    border-radius: 8px;
    font-size: 12px;
}

.message-sources h5 {
    margin-bottom: 8px;
    color: var(--text-primary);
}

.source-item {
    padding: 4px 0;
    color: var(--text-secondary);
}

.typing-indicator {
    display: flex;
    gap: 4px;
    padding: 12px 16px;
}

.typing-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--text-secondary);
    animation: typing 1.4s infinite;
}

.typing-dot:nth-child(2) {
    animation-delay: 0.2s;
}

.typing-dot:nth-child(3) {
    animation-delay: 0.4s;
}

@keyframes typing {
    0%, 60%, 100% {
        transform: translateY(0);
    }
    30% {
        transform: translateY(-10px);
    }
}

/* Input Area */
.input-area {
    padding: 20px;
    border-top: 1px solid var(--border-color);
}

.input-wrapper {
    display: flex;
    gap: 12px;
    margin-bottom: 8px;
}

.input-wrapper input {
    flex: 1;
    padding: 12px 16px;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 14px;
    transition: all 0.3s;
}

.input-wrapper input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.input-wrapper input:disabled {
    background: var(--bg-primary);
    cursor: not-allowed;
}

.btn-send {
    padding: 12px 24px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s;
}

.btn-send:hover:not(:disabled) {
    background: var(--primary-dark);
}

.btn-send:disabled {
    background: var(--border-color);
    cursor: not-allowed;
}

.input-hint {
    font-size: 12px;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 6px;
}

/* Loading spinner */
.spinner {
    display: inline-block;
    width: 16px;
    height: 16px;
    border: 2px solid var(--border-color);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Scrollbar */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-primary);
}

::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-secondary);
}

/* Responsive */
@media (max-width: 1024px) {
    .main-content {
        grid-template-columns: 300px 1fr;
    }
}

@media (max-width: 768px) {
    .main-content {
        grid-template-columns: 1fr;
    }
    
    .sidebar {
        display: none;
    }
}