body { font-family: 'Noto Sans KR', sans-serif; }
        .font-serif { font-family: 'Nanum Myeongjo', serif; }
        
        .glass-panel {
            background: rgba(255, 255, 255, 0.95);
            backdrop-filter: blur(10px);
            border: 1px solid rgba(229, 231, 235, 0.5);
        }
        
        /* A4 Paper Styling */
        .a4-page {
            width: 210mm;
            min-height: 297mm;
            padding: 20mm;
            background: white;
            box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
            margin: 0 auto;
        }

        /* Source Highlight Animation */
        .source-highlight {
            background-color: rgba(16, 185, 129, 0.1);
            border-bottom: 2px solid #10B981;
            cursor: pointer;
            transition: background-color 0.2s;
        }
        .source-highlight:hover {
            background-color: rgba(16, 185, 129, 0.2);
        }
        .source-highlight.active {
            background-color: rgba(16, 185, 129, 0.3);
            outline: 2px solid #10B981;
            border-radius: 2px;
        }

        /* Chat Bubble Styles */
        .chat-bubble-ai {
            background-color: #F3F4F6;
            color: #374151;
            border-bottom-left-radius: 0;
        }
        .chat-bubble-user {
            background-color: #7C3AED;
            color: white;
            border-bottom-right-radius: 0;
        }

        /* Sidebar Styles */
        .sidebar-item {
            position: relative;
            overflow: hidden;
            transition: all 0.3s ease;
        }
        .sidebar-item::before {
            content: '';
            position: absolute;
            left: 0;
            top: 0;
            height: 100%;
            width: 4px;
            background: #7C3AED;
            transform: scaleY(0);
            transition: transform 0.3s ease;
        }
        .sidebar-item.active::before {
            transform: scaleY(1);
        }
        .sidebar-item.active {
            background: #F3F4F6;
            color: #7C3AED;
        }

        /* Animations */
        @keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }
        .fade-in { animation: fadeIn 0.3s ease-out forwards; }

        /* Custom Scrollbar */
        ::-webkit-scrollbar { width: 6px; }
        ::-webkit-scrollbar-track { background: transparent; }
        ::-webkit-scrollbar-thumb { background: #cbd5e1; border-radius: 3px; }
        ::-webkit-scrollbar-thumb:hover { background: #94a3b8; }