feat: Add iOS-style blur bar for mobile buttons and landscape optimizations

Mobile Portrait Enhancements:
- Added iOS-style blur backdrop behind fixed buttons
- Frosted glass effect with backdrop-filter: blur(20px) saturate(180%)
- Semi-transparent background with border-top separator
- Dark mode variant for theme consistency
- Z-index 98 (below buttons at 99)
- pointer-events: none to maintain button animations and clicks

Landscape Orientation Fixes:
- Hide profile photo to maximize vertical space
- Compact header with reduced font sizes (1.2rem)
- Reduced padding on action bar, sidebar, and sections
- Optimized button sizes (40x40px) and positions
- Fixed hamburger menu positioning in landscape

Files Modified:
- static/css/05-responsive/_breakpoints.css: Added blur backdrop and landscape styles
- templates/index.html: Added fixed-buttons-backdrop element
- tests/mjs/48-mobile-landscape-and-blur-test.mjs: Comprehensive test suite

Test Results:
✅ Blur backdrop exists with correct blur effect
✅ Fixed position at bottom with 90px height
✅ Border separator visible (0.5px)
✅ Photo hidden in landscape mode
✅ Compact sizing applied in landscape
✅ All animations maintained (backdrop separate from buttons)

Screenshots:
- tests/screenshots/mobile-portrait-blur-bar.png
- tests/screenshots/mobile-landscape-optimized.png

static/css/05-responsive/_breakpoints.css

@@ -665,3 +665,107 @@
     }
 }
 
+
+/* ========================================
+   Mobile: iOS-Style Button Bar with Blur
+   ======================================== */
+
+@media (max-width: 540px) {
+    /* iOS-style blur bar behind fixed buttons */
+    .fixed-buttons-backdrop {
+        position: fixed;
+        bottom: 0;
+        left: 0;
+        right: 0;
+        height: 90px; /* Enough to cover button area */
+        background: rgba(255, 255, 255, 0.8);
+        backdrop-filter: blur(20px) saturate(180%);
+        -webkit-backdrop-filter: blur(20px) saturate(180%);
+        border-top: 0.5px solid rgba(0, 0, 0, 0.1);
+        z-index: 98; /* Below buttons (99) but above content */
+        pointer-events: none; /* Don't block button clicks */
+    }
+
+    /* Dark mode blur bar */
+    [data-color-theme="dark"] .fixed-buttons-backdrop,
+    [data-color-theme="auto"] .fixed-buttons-backdrop {
+        background: rgba(30, 30, 30, 0.8);
+        border-top: 0.5px solid rgba(255, 255, 255, 0.1);
+    }
+}
+
+/* ========================================
+   Landscape Orientation Fixes
+   ======================================== */
+
+@media (max-width: 915px) and (orientation: landscape) {
+    /* Reduce header size in landscape */
+    .cv-header {
+        margin-bottom: 1rem !important;
+    }
+
+    .cv-name {
+        font-size: 1.2rem !important;
+    }
+
+    .years-experience {
+        font-size: 0.9em !important;
+    }
+
+    /* Hide photo in landscape to save vertical space */
+    .cv-photo {
+        display: none !important;
+    }
+
+    /* Compact action bar */
+    .action-bar {
+        padding: 0.5rem 1rem !important;
+    }
+
+    /* Reduce sidebar padding */
+    .cv-sidebar {
+        padding: 1rem !important;
+    }
+
+    /* Compact sections */
+    .section-title {
+        font-size: 1rem !important;
+        margin-bottom: 0.5rem !important;
+    }
+
+    /* Reduce margins */
+    .experience-item,
+    .project-item,
+    .course-item {
+        margin-bottom: 1rem !important;
+    }
+
+    /* Make hamburger menu more accessible in landscape */
+    .hamburger-menu {
+        position: fixed !important;
+        top: 10px !important;
+        left: 10px !important;
+        z-index: 1001 !important;
+    }
+
+    /* Adjust fixed buttons for landscape */
+    .fixed-btn {
+        bottom: 1rem !important;
+        width: 40px !important;
+        height: 40px !important;
+    }
+
+    .back-to-top-btn {
+        right: 1rem !important;
+    }
+
+    .shortcuts-btn {
+        left: 1rem !important;
+        bottom: 5rem !important;
+    }
+
+    .zoom-toggle-btn {
+        left: 1rem !important;
+        bottom: 9rem !important;
+    }
+}