:root {
            --toolbar-height: 50px;
            --editor-bg: #f4f4f4;
            --viewer-bg: #ffffff;
            --toolbar-bg: #ffffff;
            --border-color: #dddddd;
            --text-color: #222222;
            --button-bg: #007bff;
            --button-hover-bg: #0069d9;
            --textarea-bg: #ffffff;
            --statusbar-height: 24px;
            --context-bar-height: 28px;
        }
        
        body, html {
            margin: 0;
            padding: 0;
            width: 100%;
            height: 100%;
            overflow: hidden;
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
            background-color: var(--editor-bg);
            color: var(--text-color);
        }

        #app-container {
            display: flex;
            flex-direction: column;
            height: 100vh;
        }

        #toolbar {
            height: var(--toolbar-height);
            background-color: var(--toolbar-bg);
            display: flex;
            align-items: center;
            padding: 0 10px;
            border-bottom: 1px solid var(--border-color);
            flex-shrink: 0;
            z-index: 10;
            gap: 10px;
        }

        #toolbar button {
            width: 36px;
            height: 36px;
            padding: 0;
            font-size: 1.4em;
            border: 1px solid var(--border-color);
            background-color: var(--textarea-bg);
            color: var(--text-color);
            border-radius: 4px;
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: center;
            transition: background-color 0.2s, transform 0.1s;
        }

        #toolbar button:hover {
            background-color: var(--editor-bg);
        }
        
        #toolbar button:active {
            transform: scale(0.95);
        }

        #toolbar #render-button {
            color: #4CAF50; /* Green icon */
        }
        
        #toolbar #export-stl-button {
            font-size: 0.9em;
            font-weight: bold;
        }

        #toolbar #export-scad-button {
            font-size: 0.7em;
            font-weight: bold;
        }

        #main-content {
            display: flex;
            flex-grow: 1;
            overflow: hidden;
        }

        #editor-pane {
            flex: 1;
            min-width: 200px;
            height: 100%;
            display: flex;
            flex-direction: column;
        }

        #editor-container {
            position: relative;
            flex-grow: 1;
            border-right: 1px solid var(--border-color);
            overflow: hidden; /* clips the children */
        }

        #code-editor, #highlighting-layer {
            margin: 0;
            padding: 10px;
            border: 0;
            outline: 0;
            box-sizing: border-box;
            
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;

            font-family: 'Fira Code', 'Consolas', 'Monaco', monospace;
            font-size: 14px;
            line-height: 1.5;
            
            white-space: pre-wrap;
            word-wrap: break-word;
            overflow: auto;
        }

        #code-editor {
            resize: none;
            background: transparent;
            color: transparent; /* Hide original text */
            caret-color: var(--text-color); /* But show the caret */
            z-index: 1;
            -webkit-text-fill-color: transparent; /* For Safari */
        }

        #highlighting-layer {
            background-color: var(--textarea-bg);
            color: var(--text-color);
            z-index: 0;
            pointer-events: none; /* Let clicks pass through */
        }
        
        #highlighting-layer code {
            display: block;
            font: inherit;
        }

        .token-comment { color: #00a0a0; } /* Cyan/Teal */
        .token-shape { color: #5f4606; }   /* Dark Yellow */
        .token-variable { color: #007bff; }/* Blue */
        .token-string { color: #28a745; }  /* Green */
        .token-number { color: #fd7e14; }  /* Orange */
        .token-invalid {
            color: #d9534f; /* Red */
            text-decoration: underline wavy #d9534f 1px;
        }

        #viewer-pane {
            flex: 2;
            min-width: 200px;
            height: 100%;
            background-color: var(--viewer-bg);
            position: relative;
            cursor: grab;
        }
        
        #viewer-pane:active {
            cursor: grabbing;
        }

        #viewer-pane canvas {
            display: block;
        }
        
        #viewer-error-overlay {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            box-sizing: border-box;
            background-color: var(--textarea-bg);
            color: #d9534f; /* Red for error text */
            padding: 20px;
            font-family: 'Fira Code', 'Consolas', 'Monaco', monospace;
            font-size: 14px;
            line-height: 1.6;
            white-space: pre-wrap;
            word-break: break-word;
            overflow-y: auto;
            z-index: 50; /* Above canvas, below popups */
            border: 1px solid var(--border-color);
        }

        #context-bar {
            height: var(--context-bar-height);
            line-height: calc(var(--context-bar-height) - 8px);
            background-color: var(--editor-bg);
            color: #555;
            padding: 4px 10px;
            font-size: 13px;
            font-family: 'Fira Code', 'Consolas', 'Monaco', monospace;
            overflow-x: auto;
            white-space: nowrap;
            border-top: 1px solid var(--border-color);
            box-sizing: border-box;
            flex-shrink: 0;
            -ms-overflow-style: none;  /* IE and Edge */
            scrollbar-width: none;  /* Firefox */
        }

        #context-bar::-webkit-scrollbar {
            display: none;
        }

        #status-bar {
            height: var(--statusbar-height);
            line-height: calc(var(--statusbar-height) - 8px);
            background-color: #222222;
            color: white;
            padding: 4px 10px;
            font-size: 12px;
            font-family: 'Fira Code', 'Consolas', 'Monaco', monospace;
            z-index: 20;
            text-align: right;
            backdrop-filter: blur(2px);
            flex-shrink: 0;
            box-sizing: border-box;
        }

        #resizer {
            width: 5px;
            cursor: col-resize;
            background-color: var(--border-color);
            z-index: 5;
        }

        /* --- Popup Styles --- */
        #popup-backdrop, #cheatsheet-backdrop, #error-backdrop {
            position: fixed;
            top: 0;
            left: 0;
            width: 100vw;
            height: 100vh;
            background-color: rgba(0, 0, 0, 0.4);
            z-index: 99;
        }

        #settings-popup {
            position: fixed;
            top: 50%;
            left: 50%;
            transform: translate(-50%, -50%);
            background-color: var(--toolbar-bg);
            padding: 20px 25px;
            border-radius: 8px;
            box-shadow: 0 4px 15px rgba(0,0,0,0.2);
            z-index: 100;
            width: 280px;
            display: flex;
            flex-direction: column;
            gap: 20px;
        }
        #settings-popup h3 {
            margin: 0;
            text-align: center;
            font-weight: 500;
        }

        .popup-controls {
            display: flex;
            flex-direction: column;
            gap: 15px;
        }
        
        .range-controls {
            display: grid;
            grid-template-columns: 20px 1fr auto 1fr;
            align-items: center;
            gap: 10px;
        }

        .range-controls span {
            font-size: 0.9em;
            color: #555;
            user-select: none;
        }
        
        .range-controls span:nth-of-type(2) { /* "to" */
             justify-self: center;
        }

        .range-controls input[type="number"] {
            width: 100%;
            box-sizing: border-box;
            padding: 6px;
            border: 1px solid var(--border-color);
            border-radius: 4px;
            background-color: var(--textarea-bg);
            color: var(--text-color);
            font-family: inherit;
            text-align: center;
            font-size: 0.9em;
        }
        
        .range-controls input[type="number"]::-webkit-inner-spin-button,
        .range-controls input[type="number"]::-webkit-outer-spin-button {
            -webkit-appearance: none;
            margin: 0;
        }
        .range-controls input[type="number"] {
            -moz-appearance: textfield;
        }
        
        .popup-buttons {
            display: flex;
            justify-content: flex-end;
            gap: 10px;
            margin-top: 10px;
        }

        .popup-buttons button {
            padding: 8px 16px;
            border: 1px solid var(--border-color);
            border-radius: 4px;
            cursor: pointer;
            font-size: 0.9em;
            transition: background-color 0.2s, border-color 0.2s;
        }

        #popup-ok {
            background-color: var(--button-bg);
            color: white;
            border-color: var(--button-bg);
        }
        
        #popup-ok:hover {
            background-color: var(--button-hover-bg);
            border-color: var(--button-hover-bg);
        }

        #popup-cancel {
            background-color: var(--textarea-bg);
            color: var(--text-color);
        }
        
        #popup-cancel:hover {
            background-color: var(--editor-bg);
        }

        /* --- Cheatsheet Styles --- */
        #cheatsheet-popup {
            position: fixed;
            top: 50%;
            left: 50%;
            transform: translate(-50%, -50%);
            background-color: var(--toolbar-bg);
            padding: 20px 25px;
            border-radius: 8px;
            box-shadow: 0 4px 15px rgba(0,0,0,0.2);
            z-index: 100;
            width: 80vw;
            max-width: 1000px;
            display: flex;
            flex-direction: column;
            gap: 15px;
        }

        #cheatsheet-popup h3 {
            margin: 0;
            text-align: center;
            font-weight: 500;
        }

        .cheatsheet-content {
            max-height: 70vh;
            overflow-y: auto;
            font-size: 0.9em;
        }

        .cheatsheet-content h4 {
            margin-top: 1em;
            margin-bottom: 0.5em;
            border-bottom: 1px solid var(--border-color);
            padding-bottom: 4px;
        }

        .cheatsheet-content p {
            margin: 0.3em 0;
        }
        .cheatsheet-content code {
            background-color: var(--editor-bg);
            padding: 2px 5px;
            border-radius: 3px;
            font-family: 'Fira Code', 'Consolas', 'Monaco', monospace;
        }
        .cheatsheet-content pre {
            background-color: var(--editor-bg);
            padding: 10px;
            border-radius: 4px;
            white-space: pre-wrap;
            word-break: break-all;
        }

        #cheatsheet-popup .popup-buttons, #error-popup .popup-buttons {
            justify-content: center;
        }
        #cheatsheet-popup .popup-buttons button, #error-popup .popup-buttons button {
            width: 100px;
        }
        
        /* --- Error Popup Styles --- */
        #error-popup {
            position: fixed;
            top: 50%;
            left: 50%;
            transform: translate(-50%, -50%);
            background-color: var(--toolbar-bg);
            padding: 20px 25px;
            border-radius: 8px;
            box-shadow: 0 4px 15px rgba(0,0,0,0.2);
            z-index: 100;
            width: 450px;
            max-width: 80vw;
            display: flex;
            flex-direction: column;
            gap: 15px;
            border-top: 4px solid #d9534f; /* Red top border for error */
        }

        #error-popup h3 {
            margin: 0;
            text-align: center;
            font-weight: 500;
            color: #d9534f; /* Red title text */
        }
        
        #error-popup .error-content {
            max-height: 50vh;
            overflow-y: auto;
            font-size: 0.95em;
            font-family: 'Fira Code', 'Consolas', 'Monaco', monospace;
            white-space: pre-wrap;
            word-break: break-word;
            background-color: var(--editor-bg);
            padding: 10px;
            border-radius: 4px;
        }