diff --git a/index.js b/index.js
index 5d771fa..afec942 100644
--- a/index.js
+++ b/index.js
@@ -979,60 +979,141 @@ function addDiceQuickReply() {
 }
 
 /**
- * Opens the settings popup.
+ * SettingsModal - Manages the settings popup modal
+ * Handles opening, closing, theming, and animations
  */
-function openSettingsPopup() {
-    const theme = extensionSettings.theme || 'default';
-    $('#rpg-settings-popup').attr('data-theme', theme);
-
-    // Apply custom theme colors if custom theme is selected
-    if (theme === 'custom') {
-        applyCustomThemeToSettingsPopup();
+class SettingsModal {
+    constructor() {
+        this.modal = document.getElementById('rpg-settings-popup');
+        this.content = this.modal?.querySelector('.rpg-settings-popup-content');
+        this.isAnimating = false;
     }
 
-    $('#rpg-settings-popup').fadeIn(200);
+    /**
+     * Opens the modal with proper animation
+     */
+    open() {
+        if (this.isAnimating || !this.modal) return;
+
+        // Apply theme
+        const theme = extensionSettings.theme || 'default';
+        this.modal.setAttribute('data-theme', theme);
+
+        // Apply custom theme if needed
+        if (theme === 'custom') {
+            this._applyCustomTheme();
+        }
+
+        // Open modal with CSS class
+        this.modal.classList.add('is-open');
+        this.modal.classList.remove('is-closing');
+
+        // Focus management
+        this.modal.querySelector('#rpg-close-settings')?.focus();
+    }
+
+    /**
+     * Closes the modal with animation
+     */
+    close() {
+        if (this.isAnimating || !this.modal) return;
+
+        this.isAnimating = true;
+        this.modal.classList.add('is-closing');
+        this.modal.classList.remove('is-open');
+
+        // Wait for animation to complete
+        setTimeout(() => {
+            this.modal.classList.remove('is-closing');
+            this.isAnimating = false;
+        }, 200);
+    }
+
+    /**
+     * Updates the theme in real-time (used when theme selector changes)
+     */
+    updateTheme() {
+        if (!this.modal) return;
+
+        const theme = extensionSettings.theme || 'default';
+        this.modal.setAttribute('data-theme', theme);
+
+        if (theme === 'custom') {
+            this._applyCustomTheme();
+        } else {
+            // Clear custom CSS variables to let theme CSS take over
+            this._clearCustomTheme();
+        }
+    }
+
+    /**
+     * Applies custom theme colors
+     * @private
+     */
+    _applyCustomTheme() {
+        if (!this.content || !extensionSettings.customColors) return;
+
+        this.content.style.setProperty('--rpg-bg', extensionSettings.customColors.bg);
+        this.content.style.setProperty('--rpg-accent', extensionSettings.customColors.accent);
+        this.content.style.setProperty('--rpg-text', extensionSettings.customColors.text);
+        this.content.style.setProperty('--rpg-highlight', extensionSettings.customColors.highlight);
+    }
+
+    /**
+     * Clears custom theme colors
+     * @private
+     */
+    _clearCustomTheme() {
+        if (!this.content) return;
+
+        this.content.style.setProperty('--rpg-bg', '');
+        this.content.style.setProperty('--rpg-accent', '');
+        this.content.style.setProperty('--rpg-text', '');
+        this.content.style.setProperty('--rpg-highlight', '');
+    }
+}
+
+// Global instance
+let settingsModal = null;
+
+/**
+ * Opens the settings popup.
+ * Backwards compatible wrapper for SettingsModal class.
+ */
+function openSettingsPopup() {
+    if (settingsModal) {
+        settingsModal.open();
+    }
 }
 
 /**
  * Closes the settings popup.
+ * Backwards compatible wrapper for SettingsModal class.
  */
 function closeSettingsPopup() {
-    $('#rpg-settings-popup').fadeOut(200);
+    if (settingsModal) {
+        settingsModal.close();
+    }
 }
 
 /**
  * Applies custom theme colors to the settings popup.
+ * Backwards compatible wrapper for SettingsModal class.
+ * @deprecated Use settingsModal.updateTheme() instead
  */
 function applyCustomThemeToSettingsPopup() {
-    const popup = $('#rpg-settings-popup .rpg-settings-popup-content');
-    popup.css({
-        '--rpg-bg': extensionSettings.customColors.bg,
-        '--rpg-accent': extensionSettings.customColors.accent,
-        '--rpg-text': extensionSettings.customColors.text,
-        '--rpg-highlight': extensionSettings.customColors.highlight
-    });
+    if (settingsModal) {
+        settingsModal._applyCustomTheme();
+    }
 }
 
 /**
  * Updates the settings popup theme in real-time.
+ * Backwards compatible wrapper for SettingsModal class.
  */
 function updateSettingsPopupTheme() {
-    const theme = extensionSettings.theme || 'default';
-    const popup = $('#rpg-settings-popup .rpg-settings-popup-content');
-
-    $('#rpg-settings-popup').attr('data-theme', theme);
-
-    // Apply custom theme colors if custom theme is selected
-    if (theme === 'custom') {
-        applyCustomThemeToSettingsPopup();
-    } else {
-        // Clear custom CSS variables to let theme CSS take over
-        popup.css({
-            '--rpg-bg': '',
-            '--rpg-accent': '',
-            '--rpg-text': '',
-            '--rpg-highlight': ''
-        });
+    if (settingsModal) {
+        settingsModal.updateTheme();
     }
 }
 
@@ -1040,16 +1121,26 @@ function updateSettingsPopupTheme() {
  * Sets up the settings popup functionality.
  */
 function setupSettingsPopup() {
+    // Initialize SettingsModal instance
+    settingsModal = new SettingsModal();
+
     // Open settings popup
     $('#rpg-open-settings').on('click', function() {
         openSettingsPopup();
     });
 
-    // Close settings popup
-    $('#rpg-close-settings, .rpg-settings-popup-overlay').on('click', function() {
+    // Close settings popup - close button
+    $('#rpg-close-settings').on('click', function() {
         closeSettingsPopup();
     });
 
+    // Close on backdrop click (clicking outside content)
+    $('#rpg-settings-popup').on('click', function(e) {
+        if (e.target === this) {
+            closeSettingsPopup();
+        }
+    });
+
     // Clear cache button
     $('#rpg-clear-cache').on('click', function() {
         // Clear the data
diff --git a/style.css b/style.css
index 70f3d77..8bd7905 100644
--- a/style.css
+++ b/style.css
@@ -2583,94 +2583,135 @@ body:has(.rpg-panel.rpg-position-left) #sheld {
 }
 
 /* ============================================
-   SETTINGS POPUP
+   SETTINGS MODAL - MOBILE FIRST
    ============================================ */
+
+/* CSS Custom Properties for Responsive Scaling */
+.rpg-settings-popup {
+    /* Fluid spacing */
+    --modal-padding: clamp(0.5rem, 2vw, 0.75rem);
+    --modal-gap: clamp(0.375rem, 1.5vw, 0.5rem);
+    --modal-border-width: 2px;
+
+    /* Fluid typography */
+    --modal-font-base: clamp(0.8rem, 3vw, 0.9rem);
+    --modal-font-small: clamp(0.7rem, 2.5vw, 0.8rem);
+    --modal-font-heading: clamp(0.9rem, 3.5vw, 1rem);
+
+    /* Content constraints - more height than dice roller */
+    --modal-max-width: min(90vw, 500px);
+    --modal-max-height: 75vh;
+}
+
+/* Modal Container - Hidden by default */
 .rpg-settings-popup {
     position: fixed;
-    top: 0;
-    left: 0;
-    right: 0;
-    bottom: 0;
+    inset: 0;
     z-index: 10000;
-    display: flex;
+    display: none;
     align-items: center;
     justify-content: center;
+    padding: 0.5rem;
 }
 
-.rpg-settings-popup-overlay {
+/* Open state */
+.rpg-settings-popup.is-open {
+    display: flex;
+    animation: fadeIn 0.2s ease-out;
+}
+
+/* Closing state */
+.rpg-settings-popup.is-closing {
+    display: flex;
+    animation: fadeOut 0.2s ease-in;
+}
+
+/* Backdrop overlay - using ::before pseudo-element */
+.rpg-settings-popup::before {
+    content: '';
     position: absolute;
-    top: 0;
-    left: 0;
-    right: 0;
-    bottom: 0;
-    background: rgba(0, 0, 0, 0.7);
+    inset: 0;
+    background: rgba(0, 0, 0, 0.85);
     backdrop-filter: blur(5px);
+    -webkit-backdrop-filter: blur(5px);
 }
 
+/* Modal Content Box */
 .rpg-settings-popup-content {
     position: relative;
-    background: var(--rpg-bg);
-    border: 3px solid var(--rpg-border);
-    border-radius: 0.938em;
-    max-width: 31.25rem;
-    width: 90%;
-    max-height: 80vh;
-    overflow: hidden;
+    width: 100%;
+    max-width: var(--modal-max-width);
+    height: auto;
+    max-height: var(--modal-max-height);
+    min-height: 0;
+    background: rgba(30, 30, 30, 0.8);
+    border: var(--modal-border-width) solid var(--rpg-border);
+    border-radius: 0.5rem;
+    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.9);
+    color: var(--rpg-text);
     display: flex;
     flex-direction: column;
-    box-shadow: 0 10px 50px rgba(0, 0, 0, 0.9);
-    animation: popupSlideIn 0.3s ease-out;
-    color: var(--rpg-text);
+    overflow: hidden;
+    animation: slideInUp 0.3s cubic-bezier(0.16, 1, 0.3, 1);
+    margin: auto 0;
 }
 
+/* Header */
 .rpg-settings-popup-header {
     display: flex;
     align-items: center;
     justify-content: space-between;
-    padding: 0.938em 1.25em;
+    padding: var(--modal-padding);
     background: var(--rpg-accent);
-    border-bottom: 1px solid var(--rpg-border);
+    border-bottom: var(--modal-border-width) solid var(--rpg-border);
+    flex-shrink: 0;
 }
 
 .rpg-settings-popup-header h3 {
     margin: 0;
-    font-size: 1.125rem;
+    font-size: var(--modal-font-heading);
     color: var(--rpg-highlight);
     display: flex;
     align-items: center;
-    gap: 0.625em;
+    gap: var(--modal-gap);
 }
 
+/* Close button - touch-friendly */
 .rpg-popup-close {
     background: transparent;
     border: none;
     color: var(--rpg-text);
     font-size: 1.5rem;
     cursor: pointer;
-    padding: 0;
-    width: 1.875rem;
-    height: 1.875rem;
+    padding: 0.5rem;
+    min-width: 44px;
+    min-height: 44px;
     display: flex;
     align-items: center;
     justify-content: center;
-    border-radius: 0.25em;
+    border-radius: 0.25rem;
     transition: all 0.2s ease;
 }
 
-.rpg-popup-close:hover {
+.rpg-popup-close:active {
     background: rgba(255, 255, 255, 0.1);
     color: var(--rpg-highlight);
 }
 
+/* Scrollable Body */
 .rpg-settings-popup-body {
-    padding: 1.25em;
+    padding: var(--modal-padding);
     overflow-y: auto;
-    flex: 1;
+    overflow-x: hidden;
+    -webkit-overflow-scrolling: touch;
+    flex: 1 1 auto;
+    min-height: 0;
 }
 
+/* Settings Groups */
 .rpg-settings-group {
-    margin-bottom: 1.25em;
-    padding-bottom: 1.25em;
+    margin-bottom: var(--modal-padding);
+    padding-bottom: var(--modal-padding);
     border-bottom: 1px solid var(--rpg-border);
 }
 
@@ -2679,15 +2720,16 @@ body:has(.rpg-panel.rpg-position-left) #sheld {
 }
 
 .rpg-settings-group h4 {
-    margin: 0 0 0.938em 0;
-    font-size: 0.938rem;
+    margin: 0 0 var(--modal-gap) 0;
+    font-size: var(--modal-font-base);
     color: var(--rpg-highlight);
     display: flex;
     align-items: center;
-    gap: 0.5em;
+    gap: var(--modal-gap);
+    font-weight: 600;
 }
 
-/* Apply theme to settings popup */
+/* Theme Support */
 #rpg-settings-popup[data-theme="sci-fi"] .rpg-settings-popup-content {
     --rpg-bg: #0a0e27;
     --rpg-accent: #1a1f3a;
@@ -2712,6 +2754,24 @@ body:has(.rpg-panel.rpg-position-left) #sheld {
     --rpg-border: #ff00ff;
 }
 
+/* Desktop Enhancement (1001px+) */
+@media (min-width: 1001px) {
+    .rpg-settings-popup {
+        --modal-padding: 1rem;
+        --modal-gap: 0.75rem;
+        --modal-font-base: 0.9rem;
+        --modal-font-small: 0.8rem;
+        --modal-font-heading: 1.125rem;
+        --modal-max-width: 600px;
+    }
+
+    /* Hover effects on desktop */
+    .rpg-popup-close:hover {
+        background: rgba(255, 255, 255, 0.1);
+        color: var(--rpg-highlight);
+    }
+}
+
 /* ============================================
    CHAT THOUGHT OVERLAYS
    ============================================ */
diff --git a/template.html b/template.html
index 4ba4257..6d30c04 100644
--- a/template.html
+++ b/template.html
@@ -68,17 +68,19 @@
     </div>
 </div>
 
-<!-- Settings Popup Modal -->
-<div id="rpg-settings-popup" class="rpg-settings-popup" style="display: none;">
-    <div class="rpg-settings-popup-overlay"></div>
+<!-- Settings Modal -->
+<div id="rpg-settings-popup" class="rpg-settings-popup" role="dialog" aria-modal="true" aria-labelledby="rpg-settings-title">
     <div class="rpg-settings-popup-content">
-        <div class="rpg-settings-popup-header">
-            <h3><i class="fa-solid fa-gear"></i> RPG Companion Settings</h3>
-            <button id="rpg-close-settings" class="rpg-popup-close">&times;</button>
-        </div>
+        <header class="rpg-settings-popup-header">
+            <h3 id="rpg-settings-title">
+                <i class="fa-solid fa-gear" aria-hidden="true"></i>
+                <span>RPG Companion Settings</span>
+            </h3>
+            <button id="rpg-close-settings" class="rpg-popup-close" type="button" aria-label="Close settings">&times;</button>
+        </header>
         <div class="rpg-settings-popup-body">
             <div class="rpg-settings-group">
-                <h4><i class="fa-solid fa-palette"></i> Theme</h4>
+                <h4><i class="fa-solid fa-palette" aria-hidden="true"></i> Theme</h4>
                 <div class="rpg-setting-row">
                     <label for="rpg-theme-select">Visual Theme:</label>
                     <select id="rpg-theme-select" class="rpg-select">
@@ -124,9 +126,9 @@
             </div>
 
             <div class="rpg-settings-group">
-                <h4><i class="fa-solid fa-toggle-on"></i> Display Options</h4>
+                <h4><i class="fa-solid fa-toggle-on" aria-hidden="true"></i> Display Options</h4>
                 <small class="notes" style="display: block; margin-bottom: 10px;">
-                    <i class="fa-solid fa-info-circle"></i> Use the Extensions tab to enable/disable the RPG Companion extension.
+                    <i class="fa-solid fa-info-circle" aria-hidden="true"></i> Use the Extensions tab to enable/disable the RPG Companion extension.
                 </small>
 
                 <div class="rpg-setting-row">
@@ -183,7 +185,7 @@
             </div>
 
             <div class="rpg-settings-group">
-                <h4><i class="fa-solid fa-sliders"></i> Advanced</h4>
+                <h4><i class="fa-solid fa-sliders" aria-hidden="true"></i> Advanced</h4>
 
                 <div class="rpg-setting-row">
                     <label for="rpg-generation-mode">Generation Mode:</label>
@@ -203,7 +205,7 @@
                 <!-- Clear Cache Button -->
                 <div style="margin-top: 16px; padding-top: 16px; border-top: 1px solid var(--rpg-border);">
                     <button id="rpg-clear-cache" class="rpg-btn-clear-cache">
-                        <i class="fa-solid fa-trash"></i> Clear Extension Cache
+                        <i class="fa-solid fa-trash" aria-hidden="true"></i> Clear Extension Cache
                     </button>
                 </div>
             </div>