:root {
        --primary-blue: #4285f4;
        --primary-dark: #1a73e8;
        --sidebar-bg: #1e3a8a;
        --sidebar-dark: #1e40af;
        --chat-bg: #f8fafc;
        --white: #ffffff;
        --gray-100: #f1f5f9;
        --gray-200: #e2e8f0;
        --gray-300: #cbd5e1;
        --gray-400: #94a3b8;
        --gray-500: #64748b;
        --gray-600: #475569;
        --gray-700: #334155;
        --gray-800: #1e293b;
        --gray-900: #0f172a;
        --success: #10b981;
        --danger: #ef4444;
        --warning: #f59e0b;
        --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1);
        --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
        --border-radius: 12px;
      }

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

      body {
        font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
        background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
        height: 100vh;
        display: flex;
        overflow: hidden;
      }

      /* Sidebar */
      #sidebar {
        width: 260px;
        background: var(--sidebar-bg);
        display: flex;
        flex-direction: column;
        padding: 20px;
        box-shadow: var(--shadow-lg);
        height: 100vh;
        overflow: hidden;
      }

      .sidebar-header {
        display: flex;
        align-items: center;
        gap: 12px;
        margin-bottom: 24px;
        color: white;
        flex-shrink: 0;
      }

      .sidebar-header .logo {
        width: 32px;
        height: 32px;
        background: var(--primary-blue);
        border-radius: 8px;
        display: flex;
        align-items: center;
        justify-content: center;
        font-size: 18px;
      }

      .sidebar-header h1 {
        font-size: 18px;
        font-weight: 600;
      }

      .new-chat-btn {
        background: rgba(255, 255, 255, 0.1);
        border: 1px solid rgba(255, 255, 255, 0.2);
        color: white;
        padding: 12px 16px;
        border-radius: var(--border-radius);
        cursor: pointer;
        display: flex;
        align-items: center;
        gap: 8px;
        font-size: 14px;
        font-weight: 500;
        margin-bottom: 20px;
        transition: all 0.2s ease;
        flex-shrink: 0;
      }

      .new-chat-btn:hover {
        background: rgba(255, 255, 255, 0.15);
      }

      .sidebar-section {
        margin-bottom: 20px;
        flex: 1;
        display: flex;
        flex-direction: column;
        overflow: hidden;
      }

      .sidebar-section h3 {
        color: rgba(255, 255, 255, 0.8);
        font-size: 12px;
        font-weight: 600;
        text-transform: uppercase;
        letter-spacing: 0.5px;
        margin-bottom: 12px;
        display: flex;
        align-items: center;
        gap: 8px;
        flex-shrink: 0;
      }

      .chat-history {
        flex: 1;
        overflow-y: auto;
        padding-right: 8px;
      }

      /* Custom scrollbar for chat history */
      .chat-history::-webkit-scrollbar {
        width: 4px;
      }

      .chat-history::-webkit-scrollbar-track {
        background: rgba(255, 255, 255, 0.1);
        border-radius: 2px;
      }

      .chat-history::-webkit-scrollbar-thumb {
        background: rgba(255, 255, 255, 0.3);
        border-radius: 2px;
      }

      .chat-history::-webkit-scrollbar-thumb:hover {
        background: rgba(255, 255, 255, 0.5);
      }

      .history-item {
        padding: 10px 12px;
        margin: 4px 0;
        border-radius: 8px;
        cursor: pointer;
        color: rgba(255, 255, 255, 0.8);
        font-size: 14px;
        transition: all 0.2s ease;
      }

      .history-item:hover {
        background: rgba(255, 255, 255, 0.1);
        color: white;
      }

      .sidebar-bottom {
        margin-top: auto;
        padding-top: 20px;
        border-top: 1px solid rgba(255, 255, 255, 0.1);
        flex-shrink: 0;
      }

      .sidebar-btn {
        background: none;
        border: none;
        color: rgba(255, 255, 255, 0.8);
        padding: 10px 12px;
        border-radius: 8px;
        cursor: pointer;
        display: flex;
        align-items: center;
        gap: 8px;
        font-size: 14px;
        width: 100%;
        margin: 2px 0;
        transition: all 0.2s ease;
      }

      .sidebar-btn:hover {
        background: rgba(255, 255, 255, 0.1);
        color: white;
      }

      /* Chat History Controls - Horizontal Layout */
      .chat-controls-row {
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: 6px;
        margin-bottom: 12px;
      }

      .chat-control-btn {
        background: rgba(255, 255, 255, 0.1);
        border: 1px solid rgba(255, 255, 255, 0.2);
        color: rgba(255, 255, 255, 0.8);
        padding: 8px 6px;
        border-radius: 6px;
        cursor: pointer;
        display: flex;
        flex-direction: column;
        align-items: center;
        gap: 4px;
        font-size: 10px;
        font-weight: 500;
        transition: all 0.2s ease;
        position: relative;
      }

      .chat-control-btn:hover {
        background: rgba(255, 255, 255, 0.2);
        color: white;
        transform: translateY(-1px);
        box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
      }

      .chat-control-btn i {
        font-size: 14px;
      }

      .chat-control-btn span {
        font-size: 9px;
        text-transform: uppercase;
        letter-spacing: 0.5px;
      }

      /* Tooltip styles */
      .chat-control-btn:hover::after {
        content: attr(title);
        position: absolute;
        bottom: -30px;
        left: 50%;
        transform: translateX(-50%);
        background: rgba(0, 0, 0, 0.8);
        color: white;
        padding: 4px 8px;
        border-radius: 4px;
        font-size: 10px;
        white-space: nowrap;
        z-index: 1000;
        pointer-events: none;
      }

      .chat-control-btn:hover::before {
        content: '';
        position: absolute;
        bottom: -6px;
        left: 50%;
        transform: translateX(-50%);
        border-left: 4px solid transparent;
        border-right: 4px solid transparent;
        border-bottom: 4px solid rgba(0, 0, 0, 0.8);
        z-index: 1000;
        pointer-events: none;
      }

      /* Main Content */
      #main {
        flex: 1;
        display: flex;
        flex-direction: column;
        background: var(--white);
        position: relative;
        height: 100vh;
      }

      /* Header */
      /* Main Header - Compact */
      .main-header {
        padding: 12px 24px;
        border-bottom: 1px solid var(--gray-200);
        display: flex;
        align-items: center;
        justify-content: space-between;
        background: var(--white);
      }

      .welcome-text {
        font-size: 14px;
        color: var(--gray-700);
        font-weight: 500;
      }

      .header-actions {
        display: flex;
        gap: 8px;
      }

      .header-btn {
        background: none;
        border: 1px solid var(--gray-300);
        color: var(--gray-600);
        padding: 8px 12px;
        border-radius: 8px;
        cursor: pointer;
        font-size: 14px;
        transition: all 0.2s ease;
      }

      .header-btn:hover {
        background: var(--gray-100);
      }

      /* Quick Actions */
      .quick-actions {
        padding: 0 24px 20px 24px;
        display: grid;
        grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
        gap: 12px;
        max-width: 800px;
        margin: 0 auto;
        width: 100%;
      }

      .action-card {
        background: var(--white);
        border: 1px solid var(--gray-200);
        border-radius: var(--border-radius);
        padding: 16px;
        cursor: pointer;
        transition: all 0.2s ease;
        display: flex;
        align-items: center;
        gap: 10px;
        box-shadow: var(--shadow);
      }

      .action-card:hover {
        border-color: var(--primary-blue);
        box-shadow: 0 4px 12px rgba(66, 133, 244, 0.15);
        transform: translateY(-2px);
      }

      .action-icon {
        width: 36px;
        height: 36px;
        border-radius: 8px;
        display: flex;
        align-items: center;
        justify-content: center;
        font-size: 16px;
        color: white;
        flex-shrink: 0;
      }

      .action-content h3 {
        font-size: 13px;
        font-weight: 600;
        color: var(--gray-800);
        margin-bottom: 2px;
      }

      .action-content p {
        font-size: 11px;
        color: var(--gray-500);
        line-height: 1.3;
      }

      /* Chat Area */
      .chat-container {
        flex: 1;
        display: flex;
        flex-direction: column;
        max-width: 800px;
        margin: 0 auto;
        width: 100%;
        padding: 0 24px;
        overflow: hidden;
        /* Reserve space for bottom input area */
        padding-bottom: 180px;
      }

      .chat-messages {
        flex: 1;
        overflow-y: auto;
        padding: 20px 0;
        display: flex;
        flex-direction: column;
        gap: 16px;
      }

      .message {
        display: flex;
        gap: 12px;
        max-width: 80%;
      }

      .message.user {
        margin-left: auto;
        flex-direction: row-reverse;
      }

      .message.bot {
        margin-right: auto;
      }

      .message-avatar {
        width: 32px;
        height: 32px;
        border-radius: 50%;
        display: flex;
        align-items: center;
        justify-content: center;
        font-size: 14px;
        color: white;
        flex-shrink: 0;
      }

      .message.bot .message-avatar {
        background: var(--primary-blue);
      }

      .message.user .message-avatar {
        background: var(--gray-400);
      }

      .message-content {
        background: var(--gray-100);
        padding: 12px 16px;
        border-radius: 18px;
        font-size: 14px;
        line-height: 1.5;
        color: var(--gray-800);
      }

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

      .message.bot .message-content {
        background: var(--gray-100);
        color: var(--gray-800);
      }

      /* 🚀 CODING TASK INDICATOR STYLES */
      .coding-task-indicator {
        margin: 16px 0;
        padding: 0;
        display: flex;
        justify-content: center;
      }

      .coding-indicator-content {
        background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
        border-radius: 12px;
        padding: 16px 20px;
        color: white;
        box-shadow: 0 4px 12px rgba(102, 126, 234, 0.3);
        max-width: 500px;
        width: 100%;
        animation: slideInFromTop 0.5s ease-out;
      }

      .coding-indicator-header {
        display: flex;
        align-items: center;
        gap: 12px;
        margin-bottom: 12px;
      }

      .coding-indicator-icon {
        font-size: 24px;
        animation: pulse 2s infinite;
      }

      .coding-indicator-title {
        font-size: 16px;
        font-weight: 600;
        color: white;
      }

      .coding-indicator-details {
        display: flex;
        flex-direction: column;
        gap: 6px;
        font-size: 13px;
        opacity: 0.9;
      }

      .coding-task-type {
        font-weight: 500;
      }

      .coding-technologies {
        font-style: italic;
      }

      .coding-confidence {
        font-size: 12px;
        opacity: 0.8;
      }

      @keyframes slideInFromTop {
        from {
          opacity: 0;
          transform: translateY(-20px);
        }
        to {
          opacity: 1;
          transform: translateY(0);
        }
      }

      @keyframes pulse {
        0%, 100% {
          transform: scale(1);
        }
        50% {
          transform: scale(1.1);
        }
      }

      /* Enhanced message content for coding responses */
      .message-content.coding-response {
        background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
        border-left: 4px solid var(--primary-blue);
        position: relative;
      }

      .message-content.coding-response::before {
        content: "💻";
        position: absolute;
        top: -8px;
        right: -8px;
        background: var(--primary-blue);
        color: white;
        width: 24px;
        height: 24px;
        border-radius: 50%;
        display: flex;
        align-items: center;
        justify-content: center;
        font-size: 12px;
        box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
      }

      /* Coding completion indicator */
      .coding-completion-indicator {
        margin: 12px 0;
        padding: 0;
        display: flex;
        justify-content: center;
      }

      .coding-completion-content {
        background: linear-gradient(135deg, #10b981 0%, #059669 100%);
        border-radius: 8px;
        padding: 8px 16px;
        color: white;
        display: flex;
        align-items: center;
        gap: 8px;
        font-size: 13px;
        font-weight: 500;
        box-shadow: 0 2px 8px rgba(16, 185, 129, 0.3);
        animation: slideInFromBottom 0.5s ease-out;
      }

      .coding-completion-icon {
        font-size: 16px;
        animation: bounce 1s ease-in-out;
      }

      @keyframes slideInFromBottom {
        from {
          opacity: 0;
          transform: translateY(20px);
        }
        to {
          opacity: 1;
          transform: translateY(0);
        }
      }

      @keyframes bounce {
        0%, 20%, 50%, 80%, 100% {
          transform: translateY(0);
        }
        40% {
          transform: translateY(-10px);
        }
        60% {
          transform: translateY(-5px);
        }
      }

      /* 🚀 ENHANCED CODE BLOCK STYLES */
      .code-block-container {
        margin: 16px 0;
        border-radius: 8px;
        overflow: hidden;
        background: #1e293b;
        box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
        animation: slideInFromBottom 0.3s ease-out;
      }

      .code-block-header {
        display: flex;
        justify-content: space-between;
        align-items: center;
        padding: 8px 16px;
        background: #0f172a;
        border-bottom: 1px solid #334155;
      }

      .code-language {
        font-size: 12px;
        font-weight: 600;
        color: #94a3b8;
        text-transform: uppercase;
        letter-spacing: 0.5px;
      }

      .code-actions {
        display: flex;
        gap: 8px;
      }

      .code-copy-btn,
      .code-download-btn {
        background: rgba(255, 255, 255, 0.1);
        border: 1px solid rgba(255, 255, 255, 0.2);
        color: #e2e8f0;
        padding: 4px 12px;
        border-radius: 4px;
        font-size: 12px;
        cursor: pointer;
        display: flex;
        align-items: center;
        gap: 6px;
        transition: all 0.2s ease;
      }

      .code-copy-btn:hover,
      .code-download-btn:hover {
        background: rgba(255, 255, 255, 0.2);
        border-color: rgba(255, 255, 255, 0.3);
        transform: translateY(-1px);
      }

      .code-copy-btn.copied,
      .code-download-btn.downloaded {
        background: #10b981;
        border-color: #10b981;
        color: white;
      }

      .code-block-container pre {
        margin: 0;
        padding: 16px;
        overflow-x: auto;
        background: #1e293b;
      }

      .code-block-container code {
        font-family: 'Consolas', 'Monaco', 'Courier New', monospace;
        font-size: 14px;
        line-height: 1.6;
        color: #e2e8f0;
        display: block;
      }

      .inline-code {
        background: rgba(102, 126, 234, 0.1);
        color: #667eea;
        padding: 2px 6px;
        border-radius: 4px;
        font-family: 'Consolas', 'Monaco', 'Courier New', monospace;
        font-size: 13px;
      }

      /* Streaming message animation */
      .streaming-message .message-content {
        position: relative;
      }

      .streaming-message .message-content::after {
        content: 'â–‹';
        animation: blink 1s infinite;
        color: var(--primary-blue);
        margin-left: 2px;
      }

      @keyframes blink {
        0%, 50% {
          opacity: 1;
        }
        51%, 100% {
          opacity: 0;
        }
      }

      /* Enhanced message content styling */
      .message-content h1 {
        font-size: 24px;
        font-weight: 700;
        margin: 16px 0 12px 0;
        color: var(--gray-900);
      }

      .message-content h2 {
        font-size: 20px;
        font-weight: 600;
        margin: 14px 0 10px 0;
        color: var(--gray-800);
      }

      .message-content h3 {
        font-size: 16px;
        font-weight: 600;
        margin: 12px 0 8px 0;
        color: var(--gray-700);
      }

      .message-content strong {
        font-weight: 600;
        color: var(--gray-900);
      }

      .message-content em {
        font-style: italic;
        color: var(--gray-700);
      }

      /* 🚀 AI THINKING INDICATOR STYLES */
      .ai-thinking-indicator {
        margin: 16px 0;
        padding: 0;
        display: flex;
        justify-content: center;
        animation: slideInFromBottom 0.3s ease-out;
      }

      .thinking-content {
        background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
        border-radius: 12px;
        padding: 20px;
        color: white;
        box-shadow: 0 4px 12px rgba(102, 126, 234, 0.3);
        max-width: 400px;
        width: 100%;
      }

      .thinking-header {
        display: flex;
        align-items: center;
        gap: 12px;
        margin-bottom: 16px;
      }

      .thinking-icon {
        font-size: 24px;
        animation: pulse 2s infinite;
      }

      .thinking-text {
        font-size: 16px;
        font-weight: 600;
      }

      .thinking-progress {
        background: rgba(255, 255, 255, 0.2);
        height: 4px;
        border-radius: 2px;
        overflow: hidden;
        margin-bottom: 16px;
      }

      .thinking-progress-bar {
        background: white;
        height: 100%;
        width: 0%;
        transition: width 0.8s ease;
        border-radius: 2px;
      }

      .thinking-steps {
        display: flex;
        flex-direction: column;
        gap: 8px;
      }

      .thinking-step {
        display: flex;
        align-items: center;
        gap: 8px;
        font-size: 13px;
        opacity: 0.5;
        transition: opacity 0.3s ease;
      }

      .thinking-step.active {
        opacity: 1;
        animation: fadeInScale 0.3s ease-out;
      }

      .thinking-step i {
        width: 16px;
        text-align: center;
      }

      @keyframes fadeInScale {
        from {
          opacity: 0;
          transform: scale(0.9);
        }
        to {
          opacity: 1;
          transform: scale(1);
        }
      }

      /* Input Area - Fixed at bottom */
      .input-area {
        position: fixed;
        bottom: 0;
        left: 260px; /* Account for sidebar width */
        right: 0;
        padding: 20px 24px;
        border-top: 1px solid var(--gray-200);
        background: var(--white);
        z-index: 100;
        box-shadow: 0 -2px 10px rgba(0, 0, 0, 0.1);
      }

      .input-container {
        max-width: 800px;
        margin: 0 auto;
        position: relative;
      }

      /* Combined AI Selection and Input */
      .combined-input-section {
        display: flex;
        flex-direction: column;
        gap: 12px;
      }

      .ai-controls-row {
        display: flex;
        align-items: center;
        gap: 16px;
        flex-wrap: wrap;
        font-size: 14px;
      }

      .ai-controls-row label {
        color: var(--gray-600);
        font-weight: 500;
        white-space: nowrap;
      }

      .ai-controls-row select {
        border: 1px solid var(--gray-300);
        border-radius: 8px;
        padding: 6px 12px;
        font-size: 14px;
        background: white;
        color: var(--gray-700);
        min-width: 120px;
        font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Segoe UI Emoji', 'Segoe UI Symbol', sans-serif;
      }

      .ai-controls-row select option {
        font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Segoe UI Emoji', 'Segoe UI Symbol', sans-serif;
        padding: 8px;
      }

      .input-wrapper {
        display: flex;
        align-items: center;
        background: var(--white);
        border: 1px solid var(--gray-300);
        border-radius: 24px;
        padding: 12px 16px;
        gap: 12px;
        transition: all 0.2s ease;
      }

      .input-wrapper:focus-within {
        border-color: var(--primary-blue);
        box-shadow: 0 0 0 3px rgba(66, 133, 244, 0.1);
      }

      .input-field {
        flex: 1;
        border: none;
        outline: none;
        font-size: 14px;
        color: var(--gray-800);
        background: transparent;
      }

      .input-field::placeholder {
        color: var(--gray-400);
      }

      .input-actions {
        display: flex;
        gap: 8px;
        align-items: center;
      }

      .input-btn {
        background: none;
        border: none;
        color: var(--gray-400);
        cursor: pointer;
        padding: 4px;
        border-radius: 4px;
        transition: all 0.2s ease;
      }

      .input-btn:hover {
        color: var(--gray-600);
        background: var(--gray-100);
      }

      /* Mic button recording state */
      .mic-btn.recording {
        background: #ef4444;
        color: white;
        animation: pulse 1.5s infinite;
      }

      .mic-btn.recording:hover {
        background: #dc2626;
        color: white;
      }

      @keyframes pulse {
        0% {
          box-shadow: 0 0 0 0 rgba(239, 68, 68, 0.7);
        }
        70% {
          box-shadow: 0 0 0 10px rgba(239, 68, 68, 0);
        }
        100% {
          box-shadow: 0 0 0 0 rgba(239, 68, 68, 0);
        }
      }

      .send-btn {
        background: var(--primary-blue);
        color: white;
        border: none;
        padding: 8px 16px;
        border-radius: 16px;
        cursor: pointer;
        font-size: 14px;
        font-weight: 500;
        transition: all 0.2s ease;
      }

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

      .send-btn:disabled {
        background: var(--gray-300);
        cursor: not-allowed;
      }

      /* AI Provider Selection - Hidden (moved to input area) */
      .ai-selection {
        display: none;
      }

      /* Modals */
      .modal {
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        background: rgba(0, 0, 0, 0.5);
        display: none;
        align-items: center;
        justify-content: center;
        z-index: 1000;
      }

      .modal-content {
        background: white;
        border-radius: var(--border-radius);
        box-shadow: var(--shadow-lg);
        width: 90%;
        max-width: 500px;
        max-height: 80vh;
        overflow-y: auto;
      }

      .modal-header {
        padding: 20px 24px;
        border-bottom: 1px solid var(--gray-200);
        display: flex;
        justify-content: space-between;
        align-items: center;
      }

      .modal-header h3 {
        font-size: 18px;
        font-weight: 600;
        color: var(--gray-800);
      }

      .close-btn {
        background: none;
        border: none;
        font-size: 24px;
        cursor: pointer;
        color: var(--gray-400);
        padding: 4px;
      }

      .close-btn:hover {
        color: var(--gray-600);
      }

      .modal-body {
        padding: 24px;
      }

      .modal-footer {
        padding: 20px 24px;
        border-top: 1px solid var(--gray-200);
        display: flex;
        gap: 12px;
        justify-content: flex-end;
      }

      .btn {
        padding: 10px 16px;
        border-radius: 8px;
        font-size: 14px;
        font-weight: 500;
        cursor: pointer;
        transition: all 0.2s ease;
        border: none;
      }

      .btn-primary {
        background: var(--primary-blue);
        color: white;
      }

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

      .btn-secondary {
        background: var(--gray-100);
        color: var(--gray-700);
        border: 1px solid var(--gray-300);
      }

      .btn-secondary:hover {
        background: var(--gray-200);
      }

      /* Form Elements */
      .form-group {
        margin-bottom: 20px;
      }

      .form-group label {
        display: block;
        margin-bottom: 6px;
        font-weight: 500;
        color: var(--gray-700);
        font-size: 14px;
      }

      .form-group input,
      .form-group select,
      .form-group textarea {
        width: 100%;
        padding: 10px 12px;
        border: 1px solid var(--gray-300);
        border-radius: 8px;
        font-size: 14px;
        transition: all 0.2s ease;
      }

      .form-group input:focus,
      .form-group select:focus,
      .form-group textarea:focus {
        outline: none;
        border-color: var(--primary-blue);
        box-shadow: 0 0 0 3px rgba(66, 133, 244, 0.1);
      }

      .form-group small {
        color: var(--gray-500);
        font-size: 12px;
        margin-top: 4px;
        display: block;
      }

      /* ========================================
         MOBILE-FIRST RESPONSIVE DESIGN
         ======================================== */

      /* Mobile Menu Toggle Button */
      .mobile-menu-toggle {
        display: none;
        position: fixed;
        top: 16px;
        left: 16px;
        z-index: 1001;
        background: var(--primary-blue);
        color: white;
        border: none;
        width: 48px;
        height: 48px;
        border-radius: 12px;
        cursor: pointer;
        box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
        font-size: 20px;
        transition: all 0.3s ease;
        -webkit-tap-highlight-color: transparent;
        touch-action: manipulation;
      }

      .mobile-menu-toggle:active {
        transform: scale(0.95);
      }

      .mobile-menu-toggle.active {
        background: var(--danger);
      }

      /* Mobile Overlay */
      .mobile-overlay {
        display: none;
        position: fixed;
        top: 0;
        left: 0;
        right: 0;
        bottom: 0;
        background: rgba(0, 0, 0, 0.5);
        z-index: 999;
        opacity: 0;
        transition: opacity 0.3s ease;
      }

      .mobile-overlay.active {
        opacity: 1;
      }

      /* Tablet (768px - 1024px) */
      @media (max-width: 1024px) and (min-width: 769px) {
        #sidebar {
          width: 240px;
        }

        .chat-container {
          padding: 0 20px;
          padding-bottom: 180px;
        }

        .input-area {
          left: 240px;
          padding: 16px 20px;
        }

        .message {
          max-width: 85%;
        }

        .quick-actions {
          grid-template-columns: repeat(2, 1fr);
          gap: 12px;
        }

        .action-card {
          padding: 14px;
        }

        .action-content h3 {
          font-size: 13px;
        }

        .action-content p {
          font-size: 11px;
        }
      }

      /* Mobile (max-width: 768px) - OPTIMIZED FOR MOBILE */
      @media (max-width: 768px) {
        body {
          flex-direction: column;
          background: #f5f7fa;
          overflow-x: hidden;
        }

        /* CRITICAL: Hide desktop sidebar completely */
        #sidebar {
          display: none;
          position: fixed;
          left: -100%;
          width: 280px;
          height: 100vh;
          z-index: 2000;
          transition: left 0.3s ease;
          overflow-y: auto;
          -webkit-overflow-scrolling: touch;
        }

        /* Mobile sidebar - slide in from left */
        #sidebar.active {
          display: flex;
          left: 0;
        }

        /* Mobile menu toggle */
        .mobile-menu-toggle {
          display: flex !important;
          align-items: center;
          justify-content: center;
          background: transparent;
          color: white;
          border: none;
          width: 44px;
          height: 44px;
          border-radius: 10px;
          position: fixed;
          top: 13px;
          left: 16px;
          z-index: 1002;
          font-size: 22px;
          -webkit-tap-highlight-color: transparent;
          touch-action: manipulation;
        }

        .mobile-menu-toggle:active {
          background: rgba(255, 255, 255, 0.2);
        }

        /* Mobile overlay */
        .mobile-overlay {
          display: none;
          position: fixed;
          top: 0;
          left: 0;
          right: 0;
          bottom: 0;
          background: rgba(0, 0, 0, 0.5);
          z-index: 1999;
          opacity: 0;
          transition: opacity 0.3s ease;
        }

        .mobile-overlay.active {
          display: block;
          opacity: 1;
        }

        /* Main content - Full width */
        #main {
          width: 100%;
          height: 100vh;
          margin-left: 0;
          background: #f5f7fa;
        }

        /* Header - Gradient with rounded bottom */
        .main-header {
          padding: 16px 20px;
          background: linear-gradient(135deg, #4F46E5 0%, #7C3AED 100%);
          color: white;
          position: fixed;
          top: 0;
          left: 0;
          right: 0;
          z-index: 1000;
          height: 70px;
          border-radius: 0 0 24px 24px;
          box-shadow: 0 4px 16px rgba(79, 70, 229, 0.2);
        }

        .main-header .welcome-text {
          font-size: 16px;
          font-weight: 600;
          margin-left: 48px;
        }

        .header-btn {
          background: transparent;
          color: white;
          border: none;
          padding: 10px;
          border-radius: 8px;
          font-size: 18px;
          width: 40px;
          height: 40px;
          -webkit-tap-highlight-color: transparent;
        }

        .header-btn:active {
          background: rgba(255, 255, 255, 0.15);
        }

        /* Welcome screen - Proper scrolling */
        .welcome-screen {
          padding: 90px 20px 180px 20px;
          overflow-y: auto;
          -webkit-overflow-scrolling: touch;
          height: calc(100vh - 70px);
          margin-top: 70px;
        }

        .welcome-message {
          background: #E0E7FF;
          color: #1E293B;
          padding: 16px 20px;
          border-radius: 20px;
          margin-bottom: 24px;
          font-size: 15px;
          display: flex;
          align-items: center;
          gap: 12px;
          box-shadow: 0 2px 12px rgba(79, 70, 229, 0.1);
        }

        .welcome-message .avatar {
          width: 44px;
          height: 44px;
          background: linear-gradient(135deg, #4F46E5 0%, #7C3AED 100%);
          border-radius: 50%;
          display: flex;
          align-items: center;
          justify-content: center;
          font-size: 22px;
        }

        /* Feature cards - 2x2 grid */
        .quick-actions {
          grid-template-columns: repeat(2, 1fr);
          padding: 0 20px 20px 20px;
          gap: 16px;
        }

        .action-card {
          padding: 20px 16px;
          flex-direction: column;
          text-align: center;
          gap: 12px;
          background: #ffffff;
          border-radius: 20px;
          box-shadow: 0 4px 16px rgba(0, 0, 0, 0.06);
          min-height: 150px;
          -webkit-tap-highlight-color: transparent;
          transition: transform 0.2s ease;
        }

        .action-card:active {
          transform: scale(0.98);
        }

        .action-icon {
          width: 56px;
          height: 56px;
          font-size: 26px;
          margin: 0 auto;
          border-radius: 50%;
        }

        .action-content h3 {
          font-size: 14px;
          font-weight: 700;
        }

        .action-content p {
          font-size: 12px;
          color: #64748B;
        }

        /* Chat area - Proper scrolling */
        .chat-container {
          padding: 90px 20px 180px 20px;
          overflow-y: auto;
          -webkit-overflow-scrolling: touch;
          height: calc(100vh - 70px);
          margin-top: 70px;
          scroll-behavior: smooth;
        }

        .chat-messages {
          padding: 16px 0;
          gap: 16px;
        }

        .message {
          max-width: 85%;
        }

        .message-avatar {
          width: 32px;
          height: 32px;
          font-size: 14px;
        }

        .message-content {
          padding: 12px 16px;
          font-size: 15px;
          line-height: 1.6;
        }

        /* Input area - Fixed at bottom */
        .input-area {
          position: fixed;
          bottom: 0;
          left: 0;
          right: 0;
          width: 100%;
          padding: 12px 16px;
          padding-bottom: calc(12px + env(safe-area-inset-bottom));
          background: #ffffff;
          border-top: 1px solid #E2E8F0;
          box-shadow: 0 -2px 16px rgba(0, 0, 0, 0.06);
          z-index: 1000;
        }

        .ai-controls-row {
          margin-bottom: 10px;
        }

        .ai-controls-row label {
          display: none;
        }

        .ai-controls-row select {
          width: 100%;
          padding: 10px 14px;
          font-size: 13px;
          border: 1px solid #E2E8F0;
          border-radius: 12px;
          background: #F8FAFC;
          -webkit-tap-highlight-color: transparent;
        }

        /* Input wrapper - Prevent overflow */
        .input-wrapper {
          padding: 10px 12px;
          gap: 8px;
          border-radius: 28px;
          background: #F1F5F9;
          border: none;
          max-width: 100%;
          overflow: hidden;
          -webkit-tap-highlight-color: transparent;
        }

        .input-field {
          font-size: 15px;
          flex: 1;
          min-width: 0;
        }

        .input-btn {
          padding: 8px;
          font-size: 18px;
          min-width: 36px;
          min-height: 36px;
          -webkit-tap-highlight-color: transparent;
        }

        .input-btn:active {
          transform: scale(0.92);
          color: #4F46E5;
        }

        /* Generate button - Optimized for mobile */
        .send-btn {
          background: linear-gradient(135deg, #4F46E5 0%, #7C3AED 100%);
          color: white;
          padding: 10px 20px;
          border-radius: 24px;
          font-size: 14px;
          font-weight: 600;
          white-space: nowrap;
          flex-shrink: 0;
          -webkit-tap-highlight-color: transparent;
        }

        .send-btn:active {
          transform: translateY(1px);
        }

        /* Modals - Full screen on mobile */
        .modal-content {
          width: 100%;
          height: 100vh;
          max-height: 100vh;
          border-radius: 0;
        }

        .modal-header {
          padding: 18px 20px;
          background: linear-gradient(135deg, #4F46E5 0%, #7C3AED 100%);
          color: white;
        }

        .modal-header h3 {
          font-size: 18px;
          color: white;
        }

        .modal-body {
          padding: 20px;
          overflow-y: auto;
          max-height: calc(100vh - 140px);
        }

        .btn {
          width: 100%;
          padding: 14px;
          font-size: 15px;
          border-radius: 12px;
        }
      }

      /* Small Mobile (max-width: 480px) */
      @media (max-width: 480px) {
        .main-header .welcome-text {
          font-size: 14px;
        }

        .welcome-screen,
        .chat-container {
          padding: 80px 16px 170px 16px;
        }

        .quick-actions {
          gap: 12px;
          padding: 0 16px 16px 16px;
        }

        .action-card {
          padding: 16px;
          min-height: 140px;
        }

        .action-icon {
          width: 48px;
          height: 48px;
          font-size: 22px;
        }

        .action-content h3 {
          font-size: 13px;
        }

        .action-content p {
          font-size: 11px;
        }

        .message {
          max-width: 90%;
        }

        .input-btn {
          font-size: 16px;
          min-width: 32px;
          min-height: 32px;
        }

        .send-btn {
          padding: 8px 16px;
          font-size: 13px;
        }
      }

      /* Landscape mode for mobile */
      @media (max-width: 768px) and (orientation: landscape) {
        #sidebar {
          width: 260px;
        }

        .chat-container {
          padding-bottom: 140px;
        }

        .welcome-screen {
          padding-bottom: 140px;
        }

        .input-area {
          padding: 8px 12px;
        }

        .combined-input-section {
          gap: 8px;
        }

        .ai-controls-row {
          grid-template-columns: repeat(2, 1fr);
        }

        .message-content {
          font-size: 14px;
        }
      }

      /* iOS Safe Area Support */
      @supports (padding: max(0px)) {
        .input-area {
          padding-bottom: max(12px, env(safe-area-inset-bottom));
        }

        #sidebar {
          padding-bottom: max(20px, env(safe-area-inset-bottom));
        }
      }

      /* Loading and animations */
      .loading {
        display: inline-block;
        width: 16px;
        height: 16px;
        border: 2px solid var(--gray-300);
        border-top: 2px solid var(--primary-blue);
        border-radius: 50%;
        animation: spin 1s linear infinite;
      }

      @keyframes spin {
        0% { transform: rotate(0deg); }
        100% { transform: rotate(360deg); }
      }

      .fade-in {
        animation: fadeIn 0.3s ease;
      }

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

      /* Hide elements initially */
      .chat-messages {
        display: none;
      }

      /* Welcome Screen with Quick Actions */
      /* Welcome Screen with Quick Actions */
      .welcome-screen {
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-content: flex-start;
        flex: 1;
        text-align: center;
        padding: 20px 24px;
        overflow-y: auto;
        /* Reserve space for bottom input area */
        padding-bottom: 180px;
      }

      .welcome-message {
        background: var(--primary-blue);
        color: white;
        padding: 12px 20px;
        border-radius: 20px;
        margin-bottom: 20px;
        display: flex;
        align-items: center;
        gap: 10px;
        font-size: 14px;
        box-shadow: var(--shadow);
      }

      .welcome-message .avatar {
        width: 28px;
        height: 28px;
        background: rgba(255, 255, 255, 0.2);
        border-radius: 50%;
        display: flex;
        align-items: center;
        justify-content: center;
        font-size: 14px;
      }