        :root {
            --primary-color: #1A73E8;
            --primary-dark: #1259B8;
            --secondary-color: #3C4043;
            --light-gray: #F5F7FA;
            --medium-gray: #E0E0E6;
            --dark-gray: #5F6368;
            --text-color: #202124;
            --white: #FFFFFF;
            --success-color: #34A853;
            --danger-color: #EA4335;
            --warning-color: #FBBC04;
            --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
            --border-radius: 8px;
            --box-shadow: 0 4px 12px rgba(0,0,0,0.08);
            --transition-speed: 0.3s;
        }

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

        body {
            font-family: var(--font-family);
            background-color: var(--light-gray);
            color: var(--text-color);
            line-height: 1.6;
            padding: 20px;
            min-height: 100vh;
        }

        #app {
            display: flex;
            flex-direction: column;
            height: calc(100vh - 40px);
            background-color: var(--white);
            border-radius: var(--border-radius);
            box-shadow: var(--box-shadow);
            overflow: hidden;
        }

        .app-header {
            background-color: var(--primary-color);
            color: var(--white);
            padding: 15px 25px;
            display: flex;
            justify-content: space-between;
            align-items: center;
            border-bottom: 1px solid var(--primary-dark);
        }

        .app-header h1 {
            font-size: 22px;
            font-weight: 600;
            display: flex;
            align-items: center;
            gap: 10px;
        }

        .global-actions .btn {
            margin-left: 10px;
        }

        .btn {
            padding: 10px 18px;
            border: none;
            border-radius: var(--border-radius);
            cursor: pointer;
            font-size: 14px;
            font-weight: 500;
            transition: all var(--transition-speed) ease;
            display: inline-flex;
            align-items: center;
            gap: 8px;
            text-decoration: none;
        }

        .btn-primary { background-color: var(--primary-color); color: var(--white); }
        .btn-primary:hover { background-color: var(--primary-dark); }
        .btn-success { background-color: var(--success-color); color: var(--white); }
        .btn-success:hover { background-color: #2a8c42; }
        .btn-danger { background-color: var(--danger-color); color: var(--white); }
        .btn-danger:hover { background-color: #c5372c; }
        .btn-warning { background-color: var(--warning-color); color: var(--text-color); }
        .btn-warning:hover { background-color: #f2a600; }
        .btn-secondary { background-color: var(--medium-gray); color: var(--text-color); }
        .btn-secondary:hover { background-color: #c8cdd3; }
        .btn-icon { background: none; padding: 8px; font-size: 16px; color: var(--dark-gray);}
        .btn-icon:hover { color: var(--primary-color); }


        .app-main {
            display: flex;
            flex: 1;
            overflow: hidden; /* Untuk scrolling internal jika perlu */
        }

        .tree-view-panel {
            width: 350px;
            min-width: 300px;
            border-right: 1px solid var(--medium-gray);
            padding: 20px;
            overflow-y: auto;
            background-color: #FBFCFD;
        }
        
        .editor-panel {
            flex: 1;
            padding: 25px;
            overflow-y: auto;
        }

        .editor-placeholder {
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            height: 100%;
            color: var(--dark-gray);
            text-align: center;
        }
        .editor-placeholder i { font-size: 48px; margin-bottom: 15px; opacity: 0.7;}


        /* Tree Node Styling */
        .tree-node {
            list-style: none;
            margin-bottom: 4px;
        }
        .node-content {
            display: flex;
            align-items: center;
            padding: 8px 12px;
            border-radius: var(--border-radius);
            cursor: pointer;
            transition: background-color var(--transition-speed) ease, box-shadow var(--transition-speed) ease;
            margin-left: var(--level-indent, 0px); /* Dihitung oleh Vue */
        }
        .node-content:hover {
            background-color: #EFF3F8;
        }
        .node-content.selected {
            background-color: var(--primary-color);
            color: var(--white);
            box-shadow: 0 2px 8px rgba(26, 115, 232, 0.3);
        }
        .node-content.selected .node-icon, 
        .node-content.selected .node-type,
        .node-content.selected .node-actions .btn-icon {
            color: var(--white);
        }
         .node-content.selected .node-actions .btn-icon:hover {
            background-color: rgba(255,255,255,0.1);
        }


        .toggle-icon { width: 20px; text-align: center; color: var(--dark-gray); transition: transform var(--transition-speed) ease;}
        .toggle-icon.expanded { transform: rotate(90deg); }
        .node-icon { margin: 0 8px; color: var(--dark-gray); font-size: 15px; }
        .node-name { flex-grow: 1; font-size: 15px; }
        .node-type {
            font-size: 11px;
            padding: 2px 6px;
            border-radius: 4px;
            background-color: var(--medium-gray);
            color: var(--dark-gray);
            margin-left: 8px;
            font-weight: 500;
        }
        .node-actions { display: flex; align-items: center; }

        .tree-children {
            margin-left: 20px; /* Indentasi untuk anak */
            overflow: hidden;
            transition: max-height var(--transition-speed) ease-in-out;
        }

        /* Editor Panel Styling */
        .editor-header { margin-bottom: 20px; padding-bottom:15px; border-bottom:1px solid var(--medium-gray); }
        .editor-header h2 { font-size: 20px; display:flex; align-items:center; gap:10px; }
        .form-group { margin-bottom: 18px; }
        .form-label {
            display: block;
            font-size: 14px;
            font-weight: 500;
            margin-bottom: 6px;
            color: var(--dark-gray);
        }
        .form-control, .form-select {
            width: 100%;
            padding: 10px;
            border: 1px solid var(--medium-gray);
            border-radius: var(--border-radius);
            font-size: 14px;
            transition: border-color var(--transition-speed) ease, box-shadow var(--transition-speed) ease;
        }
        .form-control:focus, .form-select:focus {
            outline: none;
            border-color: var(--primary-color);
            box-shadow: 0 0 0 2px rgba(26, 115, 232, 0.2);
        }
        .checkbox-group { display: flex; align-items: center; gap: 15px; margin-top: 10px; }
        .checkbox-group label { font-weight: normal; display:flex; align-items:center; gap: 5px; }
        .checkbox-group input[type="checkbox"] { margin-right: 5px; }

        .dynamic-fields-enter-active, .dynamic-fields-leave-active {
            transition: all var(--transition-speed) ease;
            max-height: 500px; /* Cukup besar untuk mengakomodasi field */
        }
        .dynamic-fields-enter-from, .dynamic-fields-leave-to {
            opacity: 0;
            transform: translateY(-10px);
            max-height: 0;
        }
        
        .link-group, .option-group {
            display: flex;
            gap: 8px;
            margin-bottom: 8px;
            align-items: center;
        }
        .link-group input, .option-group input { flex: 1; }


        /* Icon Picker Modal */
        .modal-overlay {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background-color: rgba(0,0,0,0.6);
            display: flex;
            align-items: center;
            justify-content: center;
            z-index: 1000;
            opacity: 0;
            visibility: hidden;
            transition: opacity var(--transition-speed) ease, visibility var(--transition-speed) ease;
        }
        .modal-overlay.visible {
            opacity: 1;
            visibility: visible;
        }
        .modal-content {
            background-color: var(--white);
            padding: 25px;
            border-radius: var(--border-radius);
            box-shadow: 0 8px 25px rgba(0,0,0,0.15);
            width: 90%;
            max-width: 600px;
            transform: scale(0.95);
            transition: transform var(--transition-speed) ease;
        }
        .modal-overlay.visible .modal-content {
            transform: scale(1);
        }
        .modal-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 20px;}
        .modal-header h3 { font-size: 18px; }
        .icon-list { display: grid; grid-template-columns: repeat(auto-fill, minmax(40px, 1fr)); gap: 10px; max-height: 300px; overflow-y: auto; padding-top:10px; }
        .icon-list i {
            font-size: 20px;
            padding: 10px;
            text-align: center;
            border-radius: var(--border-radius);
            cursor: pointer;
            transition: background-color var(--transition-speed) ease, color var(--transition-speed) ease;
        }
        .icon-list i:hover { background-color: var(--primary-color); color: var(--white); }

        /* JSON Output area */
        .json-output-container {
            margin-top: 30px;
            padding-top: 20px;
            border-top: 1px solid var(--medium-gray);
        }
        .json-output-container h3 { margin-bottom: 10px; font-size: 16px; }
        .json-output {
            width: 100%;
            background: #282c34; /* Dark theme for code */
            color: #abb2bf;
            padding: 16px;
            border-radius: var(--border-radius);
            font-family: 'JetBrains Mono', monospace, 'Courier New', Courier;
            font-size: 13px;
            line-height: 1.6;
            min-height: 150px;
            max-height: 300px;
            overflow-y: auto;
            white-space: pre-wrap;
            border: none;
        }

        .btn-add-top { margin-bottom:15px; width:100%; }
        .node-actions .btn-sm { padding: 4px 8px; font-size:12px; gap: 4px; }
