diff --git a/alphabetizer-lab.html b/alphabetizer-lab.html
index 1668545..01099e2 100644
--- a/alphabetizer-lab.html
+++ b/alphabetizer-lab.html
@@ -73,7 +73,13 @@ <h2>Upload Text File</h2>
         </div>
 
         <div class="results-section" id="resultsSection" style="display: none;">
-            <div class="results-header" id="resultsHeader">Word Analysis Results</div>
+            <div class="output-header">
+                <div class="results-header" id="resultsHeader">Word Analysis Results</div>
+                <div class="font-size-control">
+                    <label for="fontSizeSlider">Font Size:</label>
+                    <input type="range" id="fontSizeSlider" class="slider" min="10" max="28" value="16" step="1">
+                </div>
+            </div>
             <div class="word-display" id="wordDisplay"></div>
             <div class="stats" id="statsDisplay"></div>
         </div>
@@ -213,6 +219,15 @@ <h2>Upload Text File</h2>
     resultsSection.style.display = 'block';
     resultsSection.scrollIntoView({ behavior: 'smooth' });
 }
+
+// Font size slider
+const fontSizeSlider = document.getElementById('fontSizeSlider');
+const wordDisplay = document.getElementById('wordDisplay');
+if (fontSizeSlider && wordDisplay) {
+    fontSizeSlider.addEventListener('input', (e) => {
+        wordDisplay.style.fontSize = e.target.value + 'px';
+    });
+}
     </script>
 </body>
 </html>
diff --git a/grid-it-lab.html b/grid-it-lab.html
index 7189a9a..1efa4f6 100644
--- a/grid-it-lab.html
+++ b/grid-it-lab.html
@@ -115,23 +115,16 @@ <h3>Grid Dimensions</h3>
 
             <div class="option-group words-per-cell-group">
                 <h3>Words Per Cell</h3>
-                <div class="radio-group">
-                    <label class="radio-option" for="oneWord">
-                        <input type="radio" id="oneWord" name="wordsPerCell" value="1" checked />
-                        <span>1 Word</span>
-                    </label>
-                    <label class="radio-option" for="twoWords">
-                        <input type="radio" id="twoWords" name="wordsPerCell" value="2" />
-                        <span>2 Words</span>
-                    </label>
-                    <label class="radio-option" for="threeWords">
-                        <input type="radio" id="threeWords" name="wordsPerCell" value="3" />
-                        <span>3 Words</span>
-                    </label>
-                    <label class="radio-option" for="fitAll">
-                        <input type="radio" id="fitAll" name="wordsPerCell" value="fit" />
-                        <span>Fit All (divide evenly)</span>
-                    </label>
+                <div class="checkbox-container">
+                    <input type="checkbox" id="fitAllCheckbox" />
+                    <label for="fitAllCheckbox">Fit All (divide evenly across grid)</label>
+                </div>
+                <div class="slider-container" id="wordsPerCellContainer">
+                    <div class="slider-label">
+                        <span>Words per cell:</span>
+                        <span id="wordsPerCellValue">1</span>
+                    </div>
+                    <input type="range" id="wordsPerCellSlider" class="slider" min="1" max="20" value="1" step="1">
                 </div>
             </div>
 
@@ -155,6 +148,10 @@ <h3>Reading Direction</h3>
         <div class="results-section" id="resultsSection" style="display: none;">
             <div class="output-header">
                 <div class="output-title">Grid View</div>
+                <div class="font-size-control">
+                    <label for="fontSizeSlider">Font Size:</label>
+                    <input type="range" id="fontSizeSlider" class="slider" min="10" max="24" value="14" step="1">
+                </div>
             </div>
             <div id="gridContainer"></div>
             <div class="stats" id="statsDisplay"></div>
@@ -226,27 +223,22 @@ <h3>Reading Direction</h3>
 
             const columnsInput = document.getElementById('columnsInput').value;
             const rowsInput = document.getElementById('rowsInput').value;
-            const wordsPerCellValue = document.querySelector('input[name="wordsPerCell"]:checked').value;
+            const fitAllChecked = document.getElementById('fitAllCheckbox').checked;
+            const wordsPerCellSliderValue = parseInt(document.getElementById('wordsPerCellSlider').value);
             const direction = document.querySelector('input[name="direction"]:checked').value;
 
             let columns, rows, wordsPerCell;
 
-            // Determine words per cell
-            if (wordsPerCellValue === 'fit') {
-                wordsPerCell = null; // Will calculate later
-            } else {
-                wordsPerCell = parseInt(wordsPerCellValue);
-            }
-
             // Calculate grid dimensions
-            if (wordsPerCellValue === 'fit') {
+            if (fitAllChecked) {
                 // "Fit All" mode: divide words evenly
                 columns = columnsInput ? parseInt(columnsInput) : 10;
                 rows = rowsInput ? parseInt(rowsInput) : Math.ceil(words.length / columns);
                 const totalCells = columns * rows;
                 wordsPerCell = Math.ceil(words.length / totalCells);
             } else {
-                // Specific words per cell
+                // Specific words per cell from slider
+                wordsPerCell = wordsPerCellSliderValue;
                 const totalWordsNeeded = words.length;
                 const cellsNeeded = Math.ceil(totalWordsNeeded / wordsPerCell);
 
@@ -313,14 +305,14 @@ <h3>Reading Direction</h3>
             gridContainer.appendChild(table);
 
             // Calculate statistics
-            const wordsUsed = wordsPerCellValue === 'fit'
+            const wordsUsed = fitAllChecked
                 ? words.length
                 : Math.min(words.length, totalCells * wordsPerCell);
             const wordsNotUsed = words.length - wordsUsed;
 
             statsDisplay.innerHTML = `
                 <strong>Grid Size:</strong> ${columns} columns × ${rows} rows (${totalCells} cells)<br>
-                <strong>Words Per Cell:</strong> ${wordsPerCellValue === 'fit' ? `~${wordsPerCell} (average)` : wordsPerCell}<br>
+                <strong>Words Per Cell:</strong> ${fitAllChecked ? `~${wordsPerCell} (average)` : wordsPerCell}<br>
                 <strong>Total Words:</strong> ${words.length}<br>
                 <strong>Words in Grid:</strong> ${wordsUsed}<br>
                 ${wordsNotUsed > 0 ? `<strong>Words Not Displayed:</strong> ${wordsNotUsed}<br>` : ''}
@@ -330,6 +322,37 @@ <h3>Reading Direction</h3>
             resultsSection.style.display = 'block';
             resultsSection.scrollIntoView({ behavior: 'smooth' });
         }
+
+        // Words per cell slider
+        const wordsPerCellSlider = document.getElementById('wordsPerCellSlider');
+        const wordsPerCellValue = document.getElementById('wordsPerCellValue');
+        const wordsPerCellContainer = document.getElementById('wordsPerCellContainer');
+        const fitAllCheckbox = document.getElementById('fitAllCheckbox');
+
+        if (wordsPerCellSlider && wordsPerCellValue) {
+            wordsPerCellSlider.addEventListener('input', (e) => {
+                wordsPerCellValue.textContent = e.target.value;
+            });
+        }
+
+        if (fitAllCheckbox && wordsPerCellContainer) {
+            fitAllCheckbox.addEventListener('change', (e) => {
+                wordsPerCellContainer.style.opacity = e.target.checked ? '0.5' : '1';
+                wordsPerCellSlider.disabled = e.target.checked;
+            });
+        }
+
+        // Font size slider
+        const fontSizeSlider = document.getElementById('fontSizeSlider');
+        const gridContainer = document.getElementById('gridContainer');
+        if (fontSizeSlider && gridContainer) {
+            fontSizeSlider.addEventListener('input', (e) => {
+                const table = gridContainer.querySelector('.grid-table');
+                if (table) {
+                    table.style.fontSize = e.target.value + 'px';
+                }
+            });
+        }
     </script>
 </body>
 </html>
diff --git a/lipogram-lab.html b/lipogram-lab.html
index eda7f1e..d08e4ca 100644
--- a/lipogram-lab.html
+++ b/lipogram-lab.html
@@ -106,6 +106,14 @@ <h2>Upload Text File</h2>
         </div>
 
         <div class="options-section" id="optionsSection" style="display: none;">
+            <div class="alphabet-section">
+                <h3>Filter Mode</h3>
+                <div class="mode-buttons">
+                    <button class="mode-btn active" id="removeModeBtn">Remove words WITH selected letters</button>
+                    <button class="mode-btn" id="keepModeBtn">Keep ONLY words WITH selected letters</button>
+                </div>
+            </div>
+
             <div class="alphabet-section">
                 <h3>English Alphabet</h3>
                 <div class="select-controls">
@@ -119,13 +127,15 @@ <h3>English Alphabet</h3>
                 <h3>Spanish Letter</h3>
                 <div class="letter-toggles" id="spanishToggles"></div>
             </div>
-
-            <button class="apply-btn" id="applyBtn">Apply Lipogram Filter</button>
         </div>
 
         <div class="results-section" id="resultsSection" style="display: none;">
             <div class="output-header">
                 <div class="output-title">Filtered Text</div>
+                <div class="font-size-control">
+                    <label for="fontSizeSlider">Font Size:</label>
+                    <input type="range" id="fontSizeSlider" class="slider" min="12" max="32" value="16" step="1">
+                </div>
             </div>
             <div class="output-text" id="outputText"></div>
             <div class="stats" id="statsDisplay"></div>
@@ -135,13 +145,15 @@ <h3>Spanish Letter</h3>
     <script>
         let fileContent = '';
         let selectedLetters = new Set();
+        let filterMode = 'remove'; // 'remove' or 'keep'
 
         const fileInput = document.getElementById('textFile');
         const optionsSection = document.getElementById('optionsSection');
-        const applyBtn = document.getElementById('applyBtn');
         const resultsSection = document.getElementById('resultsSection');
         const outputText = document.getElementById('outputText');
         const statsDisplay = document.getElementById('statsDisplay');
+        const removeModeBtn = document.getElementById('removeModeBtn');
+        const keepModeBtn = document.getElementById('keepModeBtn');
 
         const englishLetters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'.split('');
         const spanishLetters = ['Ñ'];
@@ -180,8 +192,31 @@ <h3>Spanish Letter</h3>
                 selectedLetters.add(letter);
                 element.classList.add('selected');
             }
+            // Auto-apply filter when letters are toggled
+            if (fileContent) {
+                applyLipogramFilter();
+            }
         }
 
+        // Mode button handlers
+        removeModeBtn.addEventListener('click', () => {
+            filterMode = 'remove';
+            removeModeBtn.classList.add('active');
+            keepModeBtn.classList.remove('active');
+            if (fileContent && selectedLetters.size > 0) {
+                applyLipogramFilter();
+            }
+        });
+
+        keepModeBtn.addEventListener('click', () => {
+            filterMode = 'keep';
+            keepModeBtn.classList.add('active');
+            removeModeBtn.classList.remove('active');
+            if (fileContent && selectedLetters.size > 0) {
+                applyLipogramFilter();
+            }
+        });
+
         // Select/Deselect all English letters
         document.getElementById('selectAllEnglish').addEventListener('click', () => {
             englishLetters.forEach(letter => {
@@ -189,6 +224,9 @@ <h3>Spanish Letter</h3>
                 const toggle = document.querySelector(`#englishToggles [data-letter="${letter}"]`);
                 if (toggle) toggle.classList.add('selected');
             });
+            if (fileContent) {
+                applyLipogramFilter();
+            }
         });
 
         document.getElementById('deselectAllEnglish').addEventListener('click', () => {
@@ -197,10 +235,12 @@ <h3>Spanish Letter</h3>
                 const toggle = document.querySelector(`#englishToggles [data-letter="${letter}"]`);
                 if (toggle) toggle.classList.remove('selected');
             });
+            if (fileContent) {
+                applyLipogramFilter();
+            }
         });
 
         fileInput.addEventListener('change', handleFileUpload);
-        applyBtn.addEventListener('click', applyLipogramFilter);
 
         function handleFileUpload(event) {
             const file = event.target.files[0];
@@ -212,7 +252,10 @@ <h3>Spanish Letter</h3>
                         fileContent = e.target.result;
                         optionsSection.style.display = 'block';
                         resultsSection.style.display = 'none';
-                        applyBtn.disabled = false;
+                        // Auto-apply if letters are already selected
+                        if (selectedLetters.size > 0) {
+                            applyLipogramFilter();
+                        }
                     };
                     reader.onerror = function(e) {
                         console.error('Error reading file:', e);
@@ -243,12 +286,11 @@ <h3>Spanish Letter</h3>
 
         function applyLipogramFilter() {
             if (!fileContent) {
-                alert('Please upload a text file first');
                 return;
             }
 
             if (selectedLetters.size === 0) {
-                alert('Please select at least one letter to filter');
+                resultsSection.style.display = 'none';
                 return;
             }
 
@@ -256,36 +298,62 @@ <h3>Spanish Letter</h3>
             const words = fileContent.split(/\s+/);
             const totalWords = words.filter(w => w.trim().length > 0).length;
 
-            // Filter words that don't contain any selected letters
-            const filteredWords = words.filter(word => {
-                if (word.trim().length === 0) return false;
-
-                // Check if word contains any of the selected letters
-                for (let letter of selectedLetters) {
-                    if (wordContainsLetter(word, letter)) {
-                        return false;
+            let filteredWords;
+            if (filterMode === 'remove') {
+                // Filter words that don't contain any selected letters (original behavior)
+                filteredWords = words.filter(word => {
+                    if (word.trim().length === 0) return false;
+
+                    // Check if word contains any of the selected letters
+                    for (let letter of selectedLetters) {
+                        if (wordContainsLetter(word, letter)) {
+                            return false;
+                        }
                     }
-                }
-                return true;
-            });
+                    return true;
+                });
+            } else {
+                // Keep only words that contain at least one selected letter (inverse mode)
+                filteredWords = words.filter(word => {
+                    if (word.trim().length === 0) return false;
+
+                    // Check if word contains any of the selected letters
+                    for (let letter of selectedLetters) {
+                        if (wordContainsLetter(word, letter)) {
+                            return true;
+                        }
+                    }
+                    return false;
+                });
+            }
 
             const filteredText = filteredWords.join(' ');
             const remainingWords = filteredWords.length;
             const removedWords = totalWords - remainingWords;
             const removalPercentage = ((removedWords / totalWords) * 100).toFixed(1);
+            const keptPercentage = ((remainingWords / totalWords) * 100).toFixed(1);
 
             outputText.textContent = filteredText || 'No words remaining after filter.';
 
             const selectedLettersList = Array.from(selectedLetters).join(', ');
+            const modeText = filterMode === 'remove' ? 'Removed' : 'Kept';
             statsDisplay.innerHTML = `
-                <strong>Filtered Letters:</strong> ${selectedLettersList}<br>
+                <strong>Filter Mode:</strong> ${modeText} words ${filterMode === 'remove' ? 'WITH' : 'WITHOUT'} selected letters<br>
+                <strong>Selected Letters:</strong> ${selectedLettersList}<br>
                 <strong>Original Word Count:</strong> ${totalWords}<br>
-                <strong>Remaining Words:</strong> ${remainingWords}<br>
+                <strong>Remaining Words:</strong> ${remainingWords} (${keptPercentage}%)<br>
                 <strong>Removed Words:</strong> ${removedWords} (${removalPercentage}%)
             `;
 
             resultsSection.style.display = 'block';
-            resultsSection.scrollIntoView({ behavior: 'smooth' });
+        }
+
+        // Font size slider
+        const fontSizeSlider = document.getElementById('fontSizeSlider');
+        if (fontSizeSlider) {
+            fontSizeSlider.addEventListener('input', (e) => {
+                outputText.style.fontSize = e.target.value + 'px';
+            });
         }
 
         // Initialize on page load
diff --git a/long-tail-lab.html b/long-tail-lab.html
index 1df30b5..bce0434 100644
--- a/long-tail-lab.html
+++ b/long-tail-lab.html
@@ -76,12 +76,28 @@ <h2>Upload Text File</h2>
                 </div>
             </div>
 
+            <div class="option-group">
+                <label>Whitespace Handling:</label>
+                <div class="checkbox-container">
+                    <input type="checkbox" id="ignoreLineBreaks" checked />
+                    <label for="ignoreLineBreaks">Ignore line breaks when measuring length</label>
+                </div>
+                <div class="checkbox-container">
+                    <input type="checkbox" id="ignoreWhitespace" checked />
+                    <label for="ignoreWhitespace">Ignore extra whitespace when measuring length</label>
+                </div>
+            </div>
+
             <button class="apply-btn" id="organizeBtn">Organize Text</button>
         </div>
 
         <div class="results-section" id="resultsSection" style="display: none;">
             <div class="output-header">
                 <div class="output-title">Reorganized Text</div>
+                <div class="font-size-control">
+                    <label for="fontSizeSlider">Font Size:</label>
+                    <input type="range" id="fontSizeSlider" class="slider" min="12" max="32" value="16" step="1">
+                </div>
             </div>
             <div class="output-text" id="outputText"></div>
             <div class="stats" id="statsDisplay"></div>
@@ -212,6 +228,20 @@ <h2>Upload Text File</h2>
             return text.split(/\s+/).filter(word => word.trim().length > 0);
         }
 
+        function getMeasuredLength(text) {
+            let measured = text;
+            const ignoreLineBreaks = document.getElementById('ignoreLineBreaks').checked;
+            const ignoreWhitespace = document.getElementById('ignoreWhitespace').checked;
+
+            if (ignoreLineBreaks) {
+                measured = measured.replace(/\n/g, '');
+            }
+            if (ignoreWhitespace) {
+                measured = measured.replace(/\s+/g, ' ').trim();
+            }
+            return measured.length;
+        }
+
         function organizeText() {
             if (!fileContent) {
                 alert('Please upload a text file first');
@@ -243,17 +273,18 @@ <h2>Upload Text File</h2>
                     break;
             }
 
-            // Sort by length
+            // Sort by measured length (considering whitespace options)
             segments.sort((a, b) => {
-                const lengthDiff = a.length - b.length;
+                const lengthDiff = getMeasuredLength(a) - getMeasuredLength(b);
                 return sortOrder === 'longest' ? -lengthDiff : lengthDiff;
             });
 
-            // Calculate statistics
+            // Calculate statistics using measured lengths
             const totalSegments = segments.length;
-            const avgLength = Math.round(segments.reduce((sum, s) => sum + s.length, 0) / totalSegments);
-            const minLength = Math.min(...segments.map(s => s.length));
-            const maxLength = Math.max(...segments.map(s => s.length));
+            const lengths = segments.map(s => getMeasuredLength(s));
+            const avgLength = Math.round(lengths.reduce((sum, l) => sum + l, 0) / totalSegments);
+            const minLength = Math.min(...lengths);
+            const maxLength = Math.max(...lengths);
 
             // Display results
             let displayText = '';
@@ -276,6 +307,14 @@ <h2>Upload Text File</h2>
             resultsSection.style.display = 'block';
             resultsSection.scrollIntoView({ behavior: 'smooth' });
         }
+
+        // Font size slider
+        const fontSizeSlider = document.getElementById('fontSizeSlider');
+        if (fontSizeSlider) {
+            fontSizeSlider.addEventListener('input', (e) => {
+                outputText.style.fontSize = e.target.value + 'px';
+            });
+        }
     </script>
 </body>
 </html>