diff --git a/static/css/01-foundation/_reset.css b/static/css/01-foundation/_reset.css
index 384aeb6..c68bd94 100644
--- a/static/css/01-foundation/_reset.css
+++ b/static/css/01-foundation/_reset.css
@@ -25,13 +25,16 @@ body {
   background-image: var(--page-bg-pattern);
   background-size: 40px 40px; /* For dark theme diagonal grid */
   background-attachment: fixed;
-  overflow-x: auto;
+  max-width: 100vw; /* Prevent horizontal overflow */
+  overflow-x: hidden; /* NO horizontal scroll on mobile */
 }
 
 /* Smooth scrolling */
 html {
   scroll-behavior: smooth;
   scroll-padding-top: 70px; /* Account for fixed header */
+  max-width: 100vw; /* Prevent horizontal overflow */
+  overflow-x: hidden; /* NO horizontal scroll */
 }
 
 /* Ensure Iconify icons display properly */
diff --git a/static/css/05-responsive/_breakpoints.css b/static/css/05-responsive/_breakpoints.css
index 6c407e5..8503452 100644
--- a/static/css/05-responsive/_breakpoints.css
+++ b/static/css/05-responsive/_breakpoints.css
@@ -697,15 +697,83 @@
 }
 
 /* ========================================
-   Landscape Orientation Fixes
+   Landscape Orientation Fixes (Mobile Devices)
    ======================================== */
 
 @media (max-width: 915px) and (orientation: landscape) {
+    /* CRITICAL: Prevent horizontal scroll in landscape */
+    * {
+        max-width: 100vw !important;
+    }
+
+    html, body {
+        width: 100vw !important;
+        max-width: 100vw !important;
+        overflow-x: hidden !important;
+    }
+
+    .cv-container {
+        width: 100% !important;
+        max-width: 100% !important;
+        overflow-x: hidden !important;
+        padding: 0 !important;
+        margin: 0 !important;
+    }
+
+    .cv-page {
+        width: 100% !important;
+        max-width: 100% !important;
+        margin: 0 !important;
+        transform: scale(1) !important; /* Reset zoom that might cause overflow */
+        box-shadow: none !important; /* Remove shadow that might cause overflow */
+    }
+
+    .page-content {
+        width: 100% !important;
+        max-width: 100% !important;
+        overflow-x: hidden !important;
+    }
+
+    /* Hide elements that might cause overflow */
+    .action-bar, .cv-header, .cv-sidebar, .cv-main {
+        max-width: 100% !important;
+        overflow-x: hidden !important;
+    }
+
     /* Force single column layout in landscape mobile */
+    .cv-page .page-1 .page-content,
+    .cv-page .page-2 .page-content,
     .page-1 .page-content,
     .page-2 .page-content {
         grid-template-columns: 1fr !important;
-        grid-template-rows: auto auto;
+        grid-template-rows: auto auto !important;
+        max-width: 100% !important;
+    }
+
+    /* Stack elements vertically in landscape: sidebar -> main */
+    .page-1 .cv-sidebar-left {
+        grid-column: 1;
+        grid-row: 1;
+        order: 1;
+    }
+
+    .page-1 .cv-main {
+        grid-column: 1;
+        grid-row: 2;
+        order: 2;
+    }
+
+    /* Stack elements vertically in landscape: main -> sidebar */
+    .page-2 .cv-main {
+        grid-column: 1;
+        grid-row: 1;
+        order: 1;
+    }
+
+    .page-2 .cv-sidebar-right {
+        grid-column: 1;
+        grid-row: 2;
+        order: 2;
     }
 
     /* Reduce header size in landscape */
@@ -714,28 +782,120 @@
     }
 
     .cv-name {
-        font-size: 1.2rem !important;
+        font-size: 1.4rem !important;
+        text-align: center;
     }
 
     .years-experience {
-        font-size: 0.9em !important;
+        font-size: 1em !important;
+        text-align: center;
+    }
+
+    /* Reduce photo size in landscape to ~50% width but keep visible */
+    .cv-header-content {
+        flex-direction: column;
+        align-items: center;
+        gap: 0.5rem;
     }
 
-    /* Reduce photo size in landscape to 50% */
     .cv-photo {
-        width: 50% !important;
+        position: static !important;
+        width: auto !important;
         height: auto !important;
-        max-width: 80px !important;
+        max-width: 120px !important;
+        margin: 0.5rem auto !important;
+        text-align: center;
     }
 
-    /* Compact action bar */
+    .cv-photo img {
+        width: 100% !important;
+        height: auto !important;
+    }
+
+    /* Compact action bar - keep hamburger menu visible */
     .action-bar {
-        padding: 0.5rem 1rem !important;
+        padding: 0.5rem 0.75rem !important;
+    }
+
+    /* Simplify action bar for landscape */
+    .action-bar-content {
+        grid-template-columns: 1fr !important;
+        gap: 0;
+        padding: 0;
+    }
+
+    /* Hide center controls on landscape mobile (moved to hamburger menu) */
+    .view-controls-center {
+        display: none !important;
+    }
+
+    /* Hide action buttons on landscape (available in hamburger menu) */
+    .action-buttons-right {
+        display: none !important;
+    }
+
+    /* Keep site title visible and compact */
+    .site-title {
+        display: flex;
+        justify-content: space-between;
+        align-items: center;
+        width: 100%;
+        padding: 0 0.5rem;
+        gap: 0.5rem;
+    }
+
+    .site-title-left {
+        display: flex;
+        align-items: center;
+        gap: 0.5rem;
+        flex: 1 1 auto;
+        min-width: 0;
+    }
+
+    .site-title-text {
+        white-space: nowrap;
+        overflow: hidden;
+        text-overflow: ellipsis;
+        font-size: 0.95rem !important;
+    }
+
+    /* Language selector compact */
+    .language-selector {
+        display: flex;
+        flex: 0 0 auto;
+        margin-left: auto;
+        gap: 0.25rem;
+    }
+
+    .language-selector .selector-btn {
+        padding: 0.3rem 0.6rem !important;
+        font-size: 0.85rem !important;
+        min-width: 35px !important;
+    }
+
+    /* Hide year from title in landscape mobile */
+    .site-title-year {
+        display: none !important;
+    }
+
+    /* Show mobile icon in title */
+    .site-logo-link {
+        display: none !important;
+    }
+
+    .site-icon-mobile {
+        display: inline-flex !important;
     }
 
     /* Reduce sidebar padding */
     .cv-sidebar {
-        padding: 1rem !important;
+        padding: 0.75rem !important;
+    }
+
+    /* Compact accordion headers in landscape */
+    .sidebar-accordion summary.sidebar-accordion-header {
+        padding: 6px 12px !important;
+        font-size: 0.8em !important;
     }
 
     /* Compact sections */
@@ -749,34 +909,97 @@
     .project-item,
     .course-item {
         margin-bottom: 1rem !important;
+        padding-bottom: 1rem !important;
     }
 
-    /* Make hamburger menu more accessible in landscape */
-    .hamburger-menu {
-        position: fixed !important;
-        top: 10px !important;
-        left: 10px !important;
+    /* Reduce font sizes for landscape */
+    .experience-period,
+    .experience-location,
+    .position {
+        font-size: 0.85rem !important;
+    }
+
+    .short-desc,
+    .responsibilities li {
+        font-size: 0.8rem !important;
+    }
+
+    /* Make hamburger button accessible in landscape */
+    .hamburger-btn {
+        display: flex !important; /* Force visible */
+        position: relative !important;
         z-index: 1001 !important;
+        opacity: 1 !important;
+        visibility: visible !important;
     }
 
-    /* Adjust fixed buttons for landscape */
-    .fixed-btn {
-        bottom: 1rem !important;
+    /* Adjust bottom button bar for landscape - smaller buttons */
+    .download-btn,
+    .print-friendly-btn,
+    .shortcuts-btn,
+    .info-button,
+    .back-to-top,
+    .color-theme-switcher {
         width: 40px !important;
         height: 40px !important;
+        bottom: 1rem !important;
     }
 
-    .back-to-top-btn {
-        right: 1rem !important;
+    /* Recalculate button positions for smaller 40px buttons */
+    /* 6 buttons: 6 * 40px + 5 * 10px = 290px total */
+    .download-btn {
+        left: calc(50% - 145px) !important;
+    }
+
+    .print-friendly-btn {
+        left: calc(50% - 95px) !important;
     }
 
     .shortcuts-btn {
-        left: 1rem !important;
-        bottom: 5rem !important;
+        left: calc(50% - 45px) !important;
     }
 
-    .zoom-toggle-btn {
-        left: 1rem !important;
-        bottom: 9rem !important;
+    .color-theme-switcher {
+        left: calc(50% + 5px) !important;
+    }
+
+    .info-button {
+        left: calc(50% + 55px) !important;
+    }
+
+    .back-to-top {
+        left: calc(50% + 105px) !important;
+    }
+
+    /* Real mobile devices in landscape: 5 buttons (no shortcuts) */
+    /* 5 buttons: 5 * 40px + 4 * 10px = 240px total */
+    .is-mobile-device .download-btn {
+        left: calc(50% - 120px) !important;
+    }
+
+    .is-mobile-device .print-friendly-btn {
+        left: calc(50% - 70px) !important;
+    }
+
+    .is-mobile-device .color-theme-switcher {
+        left: calc(50% - 20px) !important;
+    }
+
+    .is-mobile-device .info-button {
+        left: calc(50% + 30px) !important;
+    }
+
+    .is-mobile-device .back-to-top {
+        left: calc(50% + 80px) !important;
+    }
+
+    /* Reduce blur bar height for landscape */
+    .fixed-buttons-backdrop {
+        height: 70px !important;
+    }
+
+    /* Add bottom padding to footer for landscape */
+    footer.no-print {
+        padding-bottom: 90px !important;
     }
 }
diff --git a/tests/mjs/54-landscape-mode-test.mjs b/tests/mjs/54-landscape-mode-test.mjs
new file mode 100755
index 0000000..2e1cd2a
--- /dev/null
+++ b/tests/mjs/54-landscape-mode-test.mjs
@@ -0,0 +1,117 @@
+#!/usr/bin/env node
+
+import { chromium } from 'playwright';
+
+const LANDSCAPE_VIEWPORT = { width: 667, height: 375 }; // iPhone SE landscape
+
+(async () => {
+    const browser = await chromium.launch({ headless: true });
+
+    console.log('🧪 Testing Landscape Mode Layout\n');
+
+    // TEST 1: Android Landscape
+    console.log('📱 TEST 1: Android Landscape (Pixel 5)\n');
+    const androidContext = await browser.newContext({
+        viewport: LANDSCAPE_VIEWPORT,
+        userAgent: 'Mozilla/5.0 (Linux; Android 11; Pixel 5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.91 Mobile Safari/537.36',
+        hasTouch: true
+    });
+    const androidPage = await androidContext.newPage();
+
+    await androidPage.goto('http://localhost:1999/?lang=en&view=extended');
+    await androidPage.waitForLoadState('networkidle');
+
+    const androidLayout = await androidPage.evaluate(() => {
+        const page1 = document.querySelector('.page-1 .page-content');
+        const sidebar = document.querySelector('.cv-sidebar-left');
+        const hamburger = document.querySelector('.hamburger-btn'); // Correct class name
+        const photo = document.querySelector('.cv-photo');
+        const buttons = document.querySelector('.download-btn');
+
+        const gridCols = window.getComputedStyle(page1).gridTemplateColumns;
+        // Single column if it's just one value (e.g., "667px" not "300px 667px")
+        const singleColumn = !gridCols.includes(' ');
+
+        return {
+            gridColumns: gridCols,
+            singleColumn: singleColumn,
+            hamburgerVisible: hamburger ? window.getComputedStyle(hamburger).display !== 'none' : false,
+            photoMaxWidth: photo ? window.getComputedStyle(photo).maxWidth : 'N/A',
+            photoVisible: photo ? window.getComputedStyle(photo).display !== 'none' : false,
+            buttonWidth: buttons ? window.getComputedStyle(buttons).width : 'N/A',
+            hasHorizontalScroll: document.body.scrollWidth > window.innerWidth
+        };
+    });
+
+    console.log('Android Landscape Layout:');
+    console.log(`  • Grid columns: ${androidLayout.gridColumns}`);
+    console.log(`  • Single column: ${androidLayout.singleColumn ? '✅' : '❌'}`);
+    console.log(`  • Hamburger menu visible: ${androidLayout.hamburgerVisible ? '✅' : '❌'}`);
+    console.log(`  • Photo max-width: ${androidLayout.photoMaxWidth}`);
+    console.log(`  • Photo visible: ${androidLayout.photoVisible ? '✅' : '❌'}`);
+    console.log(`  • Button width: ${androidLayout.buttonWidth}`);
+    console.log(`  • Has horizontal scroll: ${androidLayout.hasHorizontalScroll ? '❌ FAIL' : '✅'}\n`);
+
+    await androidPage.screenshot({
+        path: 'tests/screenshots/landscape-android.png',
+        fullPage: true
+    });
+
+    await androidContext.close();
+
+    // TEST 2: iPhone Landscape
+    console.log('📱 TEST 2: iPhone Landscape (iPhone 12)\n');
+    const iphoneContext = await browser.newContext({
+        viewport: { width: 844, height: 390 }, // iPhone 12 landscape
+        userAgent: 'Mozilla/5.0 (iPhone; CPU iPhone OS 15_0 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/15.0 Mobile/15E148 Safari/604.1',
+        hasTouch: true
+    });
+    const iphonePage = await iphoneContext.newPage();
+
+    await iphonePage.goto('http://localhost:1999/?lang=en&view=extended');
+    await iphonePage.waitForLoadState('networkidle');
+
+    const iphoneLayout = await iphonePage.evaluate(() => {
+        const page1 = document.querySelector('.page-1 .page-content');
+        const photo = document.querySelector('.cv-photo');
+        const buttons = document.querySelector('.download-btn');
+
+        const gridCols = window.getComputedStyle(page1).gridTemplateColumns;
+        // Single column if it's just one value (e.g., "844px" not "300px 844px")
+        const singleColumn = !gridCols.includes(' ');
+
+        return {
+            gridColumns: gridCols,
+            singleColumn: singleColumn,
+            photoMaxWidth: photo ? window.getComputedStyle(photo).maxWidth : 'N/A',
+            photoVisible: photo ? window.getComputedStyle(photo).display !== 'none' : false,
+            buttonWidth: buttons ? window.getComputedStyle(buttons).width : 'N/A',
+            hasHorizontalScroll: document.body.scrollWidth > window.innerWidth
+        };
+    });
+
+    console.log('iPhone Landscape Layout:');
+    console.log(`  • Grid columns: ${iphoneLayout.gridColumns}`);
+    console.log(`  • Single column: ${iphoneLayout.singleColumn ? '✅' : '❌'}`);
+    console.log(`  • Photo max-width: ${iphoneLayout.photoMaxWidth}`);
+    console.log(`  • Photo visible: ${iphoneLayout.photoVisible ? '✅' : '❌'}`);
+    console.log(`  • Button width: ${iphoneLayout.buttonWidth}`);
+    console.log(`  • Has horizontal scroll: ${iphoneLayout.hasHorizontalScroll ? '❌ FAIL' : '✅'}\n`);
+
+    await iphonePage.screenshot({
+        path: 'tests/screenshots/landscape-iphone.png',
+        fullPage: true
+    });
+
+    await iphoneContext.close();
+
+    const allPassed = androidLayout.singleColumn && !androidLayout.hasHorizontalScroll &&
+                      androidLayout.hamburgerVisible && androidLayout.photoVisible &&
+                      iphoneLayout.singleColumn && !iphoneLayout.hasHorizontalScroll &&
+                      iphoneLayout.photoVisible;
+
+    console.log(`${allPassed ? '✅' : '❌'} Tests ${allPassed ? 'PASSED' : 'FAILED'}\n`);
+
+    await browser.close();
+    process.exit(allPassed ? 0 : 1);
+})();
diff --git a/tests/mjs/55-button-centering-test.mjs b/tests/mjs/55-button-centering-test.mjs
new file mode 100755
index 0000000..8abf895
--- /dev/null
+++ b/tests/mjs/55-button-centering-test.mjs
@@ -0,0 +1,197 @@
+#!/usr/bin/env node
+
+import { chromium } from 'playwright';
+
+const MOBILE_VIEWPORT = { width: 375, height: 667 };
+
+(async () => {
+    const browser = await chromium.launch({ headless: true });
+
+    console.log('🧪 Testing Button Centering on Mobile\n');
+
+    // TEST 1: Android Portrait
+    console.log('📱 TEST 1: Android Portrait (Pixel 5)\n');
+    const androidContext = await browser.newContext({
+        viewport: MOBILE_VIEWPORT,
+        userAgent: 'Mozilla/5.0 (Linux; Android 11; Pixel 5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.91 Mobile Safari/537.36',
+        hasTouch: true
+    });
+    const androidPage = await androidContext.newPage();
+
+    await androidPage.goto('http://localhost:1999/?lang=en&view=extended');
+    await androidPage.waitForLoadState('networkidle');
+
+    const androidButtons = await androidPage.evaluate(() => {
+        const viewport = {
+            width: window.innerWidth,
+            height: window.innerHeight
+        };
+
+        const buttons = {
+            download: document.querySelector('.download-btn'),
+            print: document.querySelector('.print-friendly-btn'),
+            theme: document.querySelector('.color-theme-switcher'),
+            info: document.querySelector('.info-button'),
+            backToTop: document.querySelector('.back-to-top'),
+            shortcuts: document.querySelector('.shortcuts-btn')
+        };
+
+        const positions = {};
+        let leftmostButton = Infinity;
+        let rightmostButton = 0;
+
+        for (const [name, btn] of Object.entries(buttons)) {
+            if (btn) {
+                const rect = btn.getBoundingClientRect();
+                const computed = window.getComputedStyle(btn);
+                const visible = computed.display !== 'none';
+
+                if (visible) {
+                    positions[name] = {
+                        left: Math.round(rect.left),
+                        right: Math.round(rect.right),
+                        centerX: Math.round(rect.left + rect.width / 2),
+                        visible: true
+                    };
+                    leftmostButton = Math.min(leftmostButton, rect.left);
+                    rightmostButton = Math.max(rightmostButton, rect.right);
+                } else {
+                    positions[name] = { visible: false };
+                }
+            }
+        }
+
+        const buttonBarWidth = rightmostButton - leftmostButton;
+        const buttonBarCenterX = leftmostButton + buttonBarWidth / 2;
+        const viewportCenterX = viewport.width / 2;
+        const centeringOffset = Math.abs(buttonBarCenterX - viewportCenterX);
+
+        return {
+            viewport,
+            positions,
+            buttonBarWidth: Math.round(buttonBarWidth),
+            buttonBarCenterX: Math.round(buttonBarCenterX),
+            viewportCenterX: Math.round(viewportCenterX),
+            centeringOffset: Math.round(centeringOffset),
+            isCentered: centeringOffset < 10 // Within 10px is acceptable
+        };
+    });
+
+    console.log('Android Button Positions:');
+    Object.entries(androidButtons.positions).forEach(([name, pos]) => {
+        if (pos.visible) {
+            console.log(`  • ${name}: ${pos.left}px to ${pos.right}px (center: ${pos.centerX}px)`);
+        } else {
+            console.log(`  • ${name}: HIDDEN`);
+        }
+    });
+    console.log(`\nButton Bar Analysis:`);
+    console.log(`  • Button bar width: ${androidButtons.buttonBarWidth}px`);
+    console.log(`  • Button bar center: ${androidButtons.buttonBarCenterX}px`);
+    console.log(`  • Viewport center: ${androidButtons.viewportCenterX}px`);
+    console.log(`  • Centering offset: ${androidButtons.centeringOffset}px`);
+    console.log(`  • Is centered: ${androidButtons.isCentered ? '✅' : '❌'}\n`);
+
+    await androidPage.screenshot({
+        path: 'tests/screenshots/buttons-android-portrait.png',
+        fullPage: true
+    });
+
+    await androidContext.close();
+
+    // TEST 2: iPhone Portrait
+    console.log('📱 TEST 2: iPhone Portrait (iPhone 12)\n');
+    const iphoneContext = await browser.newContext({
+        viewport: MOBILE_VIEWPORT,
+        userAgent: 'Mozilla/5.0 (iPhone; CPU iPhone OS 15_0 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/15.0 Mobile/15E148 Safari/604.1',
+        hasTouch: true
+    });
+    const iphonePage = await iphoneContext.newPage();
+
+    await iphonePage.goto('http://localhost:1999/?lang=en&view=extended');
+    await iphonePage.waitForLoadState('networkidle');
+
+    const iphoneButtons = await iphonePage.evaluate(() => {
+        const viewport = {
+            width: window.innerWidth,
+            height: window.innerHeight
+        };
+
+        const buttons = {
+            download: document.querySelector('.download-btn'),
+            print: document.querySelector('.print-friendly-btn'),
+            theme: document.querySelector('.color-theme-switcher'),
+            info: document.querySelector('.info-button'),
+            backToTop: document.querySelector('.back-to-top')
+        };
+
+        const positions = {};
+        let leftmostButton = Infinity;
+        let rightmostButton = 0;
+
+        for (const [name, btn] of Object.entries(buttons)) {
+            if (btn) {
+                const rect = btn.getBoundingClientRect();
+                const computed = window.getComputedStyle(btn);
+                const visible = computed.display !== 'none';
+
+                if (visible) {
+                    positions[name] = {
+                        left: Math.round(rect.left),
+                        right: Math.round(rect.right),
+                        centerX: Math.round(rect.left + rect.width / 2),
+                        visible: true
+                    };
+                    leftmostButton = Math.min(leftmostButton, rect.left);
+                    rightmostButton = Math.max(rightmostButton, rect.right);
+                } else {
+                    positions[name] = { visible: false };
+                }
+            }
+        }
+
+        const buttonBarWidth = rightmostButton - leftmostButton;
+        const buttonBarCenterX = leftmostButton + buttonBarWidth / 2;
+        const viewportCenterX = viewport.width / 2;
+        const centeringOffset = Math.abs(buttonBarCenterX - viewportCenterX);
+
+        return {
+            viewport,
+            positions,
+            buttonBarWidth: Math.round(buttonBarWidth),
+            buttonBarCenterX: Math.round(buttonBarCenterX),
+            viewportCenterX: Math.round(viewportCenterX),
+            centeringOffset: Math.round(centeringOffset),
+            isCentered: centeringOffset < 10
+        };
+    });
+
+    console.log('iPhone Button Positions:');
+    Object.entries(iphoneButtons.positions).forEach(([name, pos]) => {
+        if (pos.visible) {
+            console.log(`  • ${name}: ${pos.left}px to ${pos.right}px (center: ${pos.centerX}px)`);
+        } else {
+            console.log(`  • ${name}: HIDDEN`);
+        }
+    });
+    console.log(`\nButton Bar Analysis:`);
+    console.log(`  • Button bar width: ${iphoneButtons.buttonBarWidth}px`);
+    console.log(`  • Button bar center: ${iphoneButtons.buttonBarCenterX}px`);
+    console.log(`  • Viewport center: ${iphoneButtons.viewportCenterX}px`);
+    console.log(`  • Centering offset: ${iphoneButtons.centeringOffset}px`);
+    console.log(`  • Is centered: ${iphoneButtons.isCentered ? '✅' : '❌'}\n`);
+
+    await iphonePage.screenshot({
+        path: 'tests/screenshots/buttons-iphone-portrait.png',
+        fullPage: true
+    });
+
+    await iphoneContext.close();
+
+    const allPassed = androidButtons.isCentered && iphoneButtons.isCentered;
+
+    console.log(`${allPassed ? '✅' : '❌'} Tests ${allPassed ? 'PASSED' : 'FAILED'}\n`);
+
+    await browser.close();
+    process.exit(allPassed ? 0 : 1);
+})();
diff --git a/tests/mjs/56-landscape-debug-test.mjs b/tests/mjs/56-landscape-debug-test.mjs
new file mode 100755
index 0000000..426102d
--- /dev/null
+++ b/tests/mjs/56-landscape-debug-test.mjs
@@ -0,0 +1,64 @@
+#!/usr/bin/env node
+
+import { chromium } from 'playwright';
+
+const LANDSCAPE_VIEWPORT = { width: 667, height: 375 };
+
+(async () => {
+    const browser = await chromium.launch({ headless: true });
+    const context = await browser.newContext({
+        viewport: LANDSCAPE_VIEWPORT,
+        userAgent: 'Mozilla/5.0 (Linux; Android 11; Pixel 5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.91 Mobile Safari/537.36',
+        hasTouch: true
+    });
+    const page = await context.newPage();
+
+    await page.goto('http://localhost:1999/?lang=en&view=extended');
+    await page.waitForLoadState('networkidle');
+
+    const debug = await page.evaluate(() => {
+        const page1 = document.querySelector('.page-1 .page-content');
+        const computed = window.getComputedStyle(page1);
+
+        // Check media query matches
+        const landscapeMatch = window.matchMedia('(max-width: 915px) and (orientation: landscape)').matches;
+        const maxWidth915 = window.matchMedia('(max-width: 915px)').matches;
+        const orientationLandscape = window.matchMedia('(orientation: landscape)').matches;
+        const maxWidth768 = window.matchMedia('(max-width: 768px)').matches;
+
+        return {
+            viewport: {
+                width: window.innerWidth,
+                height: window.innerHeight,
+                ratio: window.innerWidth / window.innerHeight
+            },
+            mediaQueries: {
+                'max-width: 915px': maxWidth915,
+                'orientation: landscape': orientationLandscape,
+                'max-width: 915px AND landscape': landscapeMatch,
+                'max-width: 768px': maxWidth768
+            },
+            gridColumns: computed.gridTemplateColumns,
+            bodyOverflow: window.getComputedStyle(document.body).overflowX,
+            htmlOverflow: window.getComputedStyle(document.documentElement).overflowX
+        };
+    });
+
+    console.log('Landscape Debug Info:\n');
+    console.log('Viewport:');
+    console.log(`  • Width: ${debug.viewport.width}px`);
+    console.log(`  • Height: ${debug.viewport.height}px`);
+    console.log(`  • Ratio: ${debug.viewport.ratio.toFixed(2)} (${debug.viewport.ratio > 1 ? 'LANDSCAPE' : 'PORTRAIT'})\n`);
+
+    console.log('Media Query Matches:');
+    Object.entries(debug.mediaQueries).forEach(([query, matches]) => {
+        console.log(`  • ${query}: ${matches ? '✅ YES' : '❌ NO'}`);
+    });
+
+    console.log(`\nComputed Styles:`);
+    console.log(`  • Grid columns: ${debug.gridColumns}`);
+    console.log(`  • Body overflow-x: ${debug.bodyOverflow}`);
+    console.log(`  • HTML overflow-x: ${debug.htmlOverflow}\n`);
+
+    await browser.close();
+})();
diff --git a/tests/mjs/57-horizontal-scroll-debug.mjs b/tests/mjs/57-horizontal-scroll-debug.mjs
new file mode 100755
index 0000000..fb5e445
--- /dev/null
+++ b/tests/mjs/57-horizontal-scroll-debug.mjs
@@ -0,0 +1,70 @@
+#!/usr/bin/env node
+
+import { chromium } from 'playwright';
+
+const LANDSCAPE_VIEWPORT = { width: 667, height: 375 };
+
+(async () => {
+    const browser = await chromium.launch({ headless: true });
+    const context = await browser.newContext({
+        viewport: LANDSCAPE_VIEWPORT,
+        userAgent: 'Mozilla/5.0 (Linux; Android 11; Pixel 5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.91 Mobile Safari/537.36',
+        hasTouch: true
+    });
+    const page = await context.newPage();
+
+    await page.goto('http://localhost:1999/?lang=en&view=extended');
+    await page.waitForLoadState('networkidle');
+
+    const debug = await page.evaluate(() => {
+        // Find all elements wider than viewport
+        const viewportWidth = window.innerWidth;
+        const wideElements = [];
+
+        document.querySelectorAll('*').forEach((el) => {
+            const rect = el.getBoundingClientRect();
+            if (rect.width > viewportWidth) {
+                const computed = window.getComputedStyle(el);
+                wideElements.push({
+                    tag: el.tagName.toLowerCase(),
+                    id: el.id || '(no id)',
+                    classes: el.className || '(no classes)',
+                    width: Math.round(rect.width),
+                    computedWidth: computed.width,
+                    maxWidth: computed.maxWidth,
+                    overflow: computed.overflowX
+                });
+            }
+        });
+
+        // Sort by width descending
+        wideElements.sort((a, b) => b.width - a.width);
+
+        return {
+            viewportWidth,
+            bodyScrollWidth: document.body.scrollWidth,
+            documentScrollWidth: document.documentElement.scrollWidth,
+            hasHorizontalScroll: document.body.scrollWidth > viewportWidth,
+            wideElements: wideElements.slice(0, 10) // Top 10 widest
+        };
+    });
+
+    console.log(`Horizontal Scroll Debug:\n`);
+    console.log(`Viewport: ${debug.viewportWidth}px`);
+    console.log(`Body scroll width: ${debug.bodyScrollWidth}px`);
+    console.log(`Document scroll width: ${debug.documentScrollWidth}px`);
+    console.log(`Has horizontal scroll: ${debug.hasHorizontalScroll ? '❌ YES' : '✅ NO'}\n`);
+
+    if (debug.wideElements.length > 0) {
+        console.log(`Elements wider than viewport:\n`);
+        debug.wideElements.forEach((el, i) => {
+            console.log(`${i + 1}. <${el.tag}> #${el.id} .${el.classes}`);
+            console.log(`   Width: ${el.width}px | Max-width: ${el.maxWidth} | Overflow: ${el.overflow}`);
+            console.log(`   Computed width: ${el.computedWidth}\n`);
+        });
+    } else {
+        console.log('No elements wider than viewport found\n');
+    }
+
+    await browser.close();
+})();