.touch-target{min-height:44px;min-width:44px;padding:8px;margin:4px}button,.btn,input[type=button],input[type=submit]{min-height:44px;padding:12px 16px;border-radius:8px;font-size:16px;touch-action:manipulation;-webkit-tap-highlight-color:transparent;user-select:none;-webkit-user-select:none}input,textarea,select{min-height:44px;padding:12px 16px;font-size:16px;border-radius:8px;border:2px solid #e0e0e0;transition:border-color .2s ease}input:focus,textarea:focus,select:focus{outline:none;border-color:#1976d2;box-shadow:0 0 0 3px #1976d21a}a{min-height:44px;display:inline-flex;align-items:center;padding:8px;text-decoration:none;color:#1976d2;border-radius:4px;transition:background-color .2s ease}a:hover,a:focus{background-color:#1976d21a}.swipeable{touch-action:pan-x pan-y;-webkit-overflow-scrolling:touch}.swipe-container{overflow-x:auto;scroll-snap-type:x mandatory;-webkit-overflow-scrolling:touch;scrollbar-width:none;-ms-overflow-style:none}.swipe-container::-webkit-scrollbar{display:none}.swipe-item{scroll-snap-align:start;flex-shrink:0}.pull-to-refresh{overscroll-behavior-y:contain;touch-action:pan-x pan-down pinch-zoom}.pull-indicator{position:absolute;top:-60px;left:50%;transform:translate(-50%);width:40px;height:40px;border-radius:50%;background:#1976d2;color:#fff;display:flex;align-items:center;justify-content:center;transition:transform .3s ease}.pull-indicator.active{transform:translate(-50%) rotate(180deg)}.haptic-light{animation:haptic-pulse-light .1s ease-out}.haptic-medium{animation:haptic-pulse-medium .15s ease-out}.haptic-heavy{animation:haptic-pulse-heavy .2s ease-out}@keyframes haptic-pulse-light{0%{transform:scale(1)}50%{transform:scale(1.02)}to{transform:scale(1)}}@keyframes haptic-pulse-medium{0%{transform:scale(1)}50%{transform:scale(1.05)}to{transform:scale(1)}}@keyframes haptic-pulse-heavy{0%{transform:scale(1)}50%{transform:scale(1.08)}to{transform:scale(1)}}.responsive-grid{display:grid;gap:16px;padding:16px}@media (max-width: 480px){.responsive-grid{grid-template-columns:1fr;gap:12px;padding:12px}}@media (min-width: 481px) and (max-width: 768px){.responsive-grid{grid-template-columns:repeat(2,1fr)}}@media (min-width: 769px) and (max-width: 1024px){.responsive-grid{grid-template-columns:repeat(3,1fr)}}@media (min-width: 1025px){.responsive-grid{grid-template-columns:repeat(4,1fr)}}.mobile-nav{position:fixed;bottom:0;left:0;right:0;background:#fff;border-top:1px solid #e0e0e0;padding:8px 0;z-index:1000;display:flex;justify-content:space-around;align-items:center;box-shadow:0 -2px 10px #0000001a}.mobile-nav-item{display:flex;flex-direction:column;align-items:center;padding:8px 12px;min-width:60px;text-decoration:none;color:#666;transition:color .2s ease}.mobile-nav-item.active{color:#1976d2}.mobile-nav-icon{font-size:24px;margin-bottom:4px}.mobile-nav-label{font-size:12px;font-weight:500}.fab{position:fixed;bottom:80px;right:16px;width:56px;height:56px;border-radius:50%;background:#1976d2;color:#fff;border:none;box-shadow:0 4px 12px #0000004d;display:flex;align-items:center;justify-content:center;font-size:24px;cursor:pointer;transition:all .3s ease;z-index:999}.fab:hover{transform:scale(1.1);box-shadow:0 6px 16px #0006}.fab:active{transform:scale(.95)}.exam-question-card{padding:20px;margin:16px;border-radius:12px;background:#fff;box-shadow:0 2px 8px #0000001a;touch-action:manipulation}.exam-option{padding:16px 20px;margin:8px 0;border:2px solid #e0e0e0;border-radius:8px;background:#fff;cursor:pointer;transition:all .2s ease;min-height:60px;display:flex;align-items:center;font-size:16px;line-height:1.4}.exam-option:hover{border-color:#1976d2;background:#f8f9ff}.exam-option.selected{border-color:#1976d2;background:#1976d2;color:#fff}.exam-option:active{transform:scale(.98)}.offline-banner{position:fixed;top:0;left:0;right:0;background:#ff9800;color:#fff;padding:12px;text-align:center;font-weight:500;z-index:1001;transform:translateY(-100%);transition:transform .3s ease}.offline-banner.show{transform:translateY(0)}.pwa-install-prompt{position:fixed;bottom:0;left:0;right:0;background:#fff;border-top:1px solid #e0e0e0;padding:16px;box-shadow:0 -4px 12px #0000001a;z-index:1002;transform:translateY(100%);transition:transform .3s ease}.pwa-install-prompt.show{transform:translateY(0)}.pwa-install-content{display:flex;align-items:center;gap:12px}.pwa-install-icon{font-size:32px;color:#1976d2}.pwa-install-text{flex:1}.pwa-install-title{font-weight:600;margin-bottom:4px}.pwa-install-description{font-size:14px;color:#666}.pwa-install-actions{display:flex;gap:8px}.pwa-install-button{padding:8px 16px;border:none;border-radius:6px;font-weight:500;cursor:pointer;transition:background-color .2s ease}.pwa-install-button.primary{background:#1976d2;color:#fff}.pwa-install-button.secondary{background:#f5f5f5;color:#666}.loading-spinner{width:24px;height:24px;border:2px solid #e0e0e0;border-top:2px solid #1976d2;border-radius:50%;animation:spin 1s linear infinite}@keyframes spin{0%{transform:rotate(0)}to{transform:rotate(360deg)}}.loading-skeleton{background:linear-gradient(90deg,#f0f0f0 25%,#e0e0e0,#f0f0f0 75%);background-size:200% 100%;animation:loading-shimmer 1.5s infinite}@keyframes loading-shimmer{0%{background-position:-200% 0}to{background-position:200% 0}}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}.focus-visible{outline:2px solid #1976d2;outline-offset:2px}@media (prefers-contrast: high){button,.btn{border:2px solid currentColor}.exam-option{border-width:3px}.exam-option.selected{border-width:4px}}@media (prefers-reduced-motion: reduce){*{animation-duration:.01ms!important;animation-iteration-count:1!important;transition-duration:.01ms!important}}@media (prefers-color-scheme: dark){.exam-question-card{background:#2d2d2d;color:#fff}.exam-option{background:#3d3d3d;border-color:#555;color:#fff}.exam-option:hover{background:#4d4d4d}.mobile-nav{background:#2d2d2d;border-top-color:#555}.mobile-nav-item{color:#ccc}.mobile-nav-item.active{color:#64b5f6}}@supports (padding: max(0px)){.mobile-nav{padding-bottom:max(8px,env(safe-area-inset-bottom))}.fab{bottom:max(80px,calc(80px + env(safe-area-inset-bottom)))}.pwa-install-prompt{padding-bottom:max(16px,env(safe-area-inset-bottom))}}@media (orientation: landscape) and (max-height: 500px){.mobile-nav{display:none}.fab{bottom:16px}.exam-question-card{margin:8px;padding:16px}}@media print{.mobile-nav,.fab,.pwa-install-prompt,.offline-banner{display:none!important}.exam-question-card{box-shadow:none;border:1px solid #ccc}}*{margin:0;padding:0;box-sizing:border-box}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif;line-height:1.6;color:#333;background-color:#f5f5f5}