/* Global reset for login page */
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        
        html, body {
            height: 100%;
            overflow-x: hidden;
        }
        
        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
        }
        
        .login-page {
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            min-height: 100vh;
            min-height: -webkit-fill-available;
            display: flex;
            align-items: center;
            justify-content: center;
            padding: 1rem;
            position: relative;
        }
        
        .login-container {
            width: 100%;
            max-width: 450px;
            margin: 0 auto;
        }
        
        .login-card {
            background: white;
            border-radius: 20px;
            box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
            overflow: hidden;
            animation: slideInUp 0.6s ease-out;
        }
        
        @keyframes slideInUp {
            from {
                opacity: 0;
                transform: translateY(30px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }
        
        .login-header {
            background: linear-gradient(135deg, #3b82f6 0%, #1e40af 100%);
            color: white;
            padding: 2rem;
            text-align: center;
        }
        
        .login-body {
            padding: 2rem;
        }
        
        /* Login Type Selector */
        .login-type-selector {
            display: flex;
            border-radius: 12px;
            background: #f3f4f6;
            padding: 0.25rem;
            margin-bottom: 2rem;
        }
        
        .login-type-btn {
            flex: 1;
            padding: 0.75rem;
            border: none;
            background: transparent;
            border-radius: 8px;
            font-weight: 600;
            font-size: 0.875rem;
            cursor: pointer;
            transition: all 0.3s ease;
            color: #6b7280;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 0.25rem;
        }
        
        .login-type-btn.active {
            background: white;
            color: #3b82f6;
            box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
        }
        
        .login-type-btn:hover:not(.active) {
            color: #374151;
        }
        
        /* Login Forms */
        .login-form {
            display: none;
        }
        
        .login-form.active {
            display: block;
            animation: fadeInUp 0.4s ease-out;
        }
        
        @keyframes fadeInUp {
            from {
                opacity: 0;
                transform: translateY(20px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }
        
        .form-group {
            margin-bottom: 1.5rem;
        }
        
        .form-label {
            display: block;
            font-weight: 600;
            margin-bottom: 0.5rem;
            color: #374151;
            font-size: 0.875rem;
            text-transform: uppercase;
            letter-spacing: 0.05em;
        }
        
        .form-input {
            width: 100%;
            padding: 0.875rem 1rem;
            border: 2px solid #e5e7eb;
            border-radius: 12px;
            font-size: 1rem;
            transition: all 0.3s ease;
            background: #f9fafb;
            -webkit-appearance: none;
            -moz-appearance: none;
            appearance: none;
        }
        
        .form-input:focus {
            outline: none;
            border-color: #3b82f6;
            background: white;
            box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
        }
        
        .code-input {
            text-align: center;
            font-size: 1.2rem;
            font-weight: bold;
            letter-spacing: 0.1em;
            text-transform: uppercase;
        }
        
        .btn-primary, .btn-secondary {
            width: 100%;
            padding: 1rem;
            border: none;
            border-radius: 12px;
            font-size: 1rem;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s ease;
            text-transform: uppercase;
            letter-spacing: 0.05em;
            -webkit-tap-highlight-color: transparent;
        }
        
        .btn-primary {
            background: linear-gradient(135deg, #3b82f6 0%, #1e40af 100%);
            color: white;
        }
        
        .btn-secondary {
            background: linear-gradient(135deg, #10b981 0%, #059669 100%);
            color: white;
        }
        
        .btn-primary:hover, .btn-secondary:hover {
            transform: translateY(-2px);
            box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.2);
        }
        
        .btn-primary:active, .btn-secondary:active {
            transform: translateY(0);
        }
        
        .error-message, .success-message {
            padding: 1rem;
            border-radius: 12px;
            margin-bottom: 1.5rem;
            font-size: 0.875rem;
            font-weight: 500;
        }
        
        .error-message {
            background: linear-gradient(135deg, #fef2f2 0%, #fee2e2 100%);
            border: 1px solid #fca5a5;
            color: #dc2626;
        }
        
        .success-message {
            background: linear-gradient(135deg, #f0fdf4 0%, #dcfce7 100%);
            border: 1px solid #86efac;
            color: #16a34a;
        }
        
        .back-home {
            position: absolute;
            top: 1rem;
            left: 1rem;
            background: rgba(255, 255, 255, 0.2);
            color: white;
            padding: 0.5rem 1rem;
            border-radius: 8px;
            text-decoration: none;
            font-weight: 500;
            transition: all 0.3s ease;
            backdrop-filter: blur(10px);
            font-size: 0.875rem;
        }
        
        .back-home:hover {
            background: rgba(255, 255, 255, 0.3);
            transform: translateY(-1px);
        }
        
        .student-info {
            background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 100%);
            border: 1px solid #93c5fd;
            border-radius: 12px;
            padding: 1.5rem;
            margin-bottom: 1.5rem;
        }
        
        .qr-scanner {
            background: #f9fafb;
            border: 2px dashed #d1d5db;
            border-radius: 12px;
            padding: 1rem;
            text-align: center;
            margin-bottom: 1rem;
        }
        
        #qr-reader {
            border: 2px solid #3b82f6;
            border-radius: 12px;
            overflow: hidden;
            margin: 0 auto;
        }
        
        .demo-code {
            padding: 0.75rem;
            border-radius: 8px;
            border: 1px solid #fbbf24;
            background: #fef3c7;
            cursor: pointer;
            transition: all 0.3s ease;
            font-size: 0.8rem;
            margin-bottom: 0.5rem;
            text-align: left;
        }
        
        .demo-code:hover {
            background: #fde68a;
            transform: translateX(4px);
        }
        
        .demo-info {
            position: fixed;
            bottom: 1rem;
            right: 1rem;
            background: rgba(0,0,0,0.85);
            color: white;
            padding: 1rem;
            border-radius: 12px;
            font-size: 0.7rem;
            max-width: 300px;
            z-index: 1000;
            backdrop-filter: blur(10px);
        }
        
        /* Responsive Design */
        
        /* iPhone SE, small phones (320px - 374px) */
        @media (max-width: 374px) {
            .login-page {
                padding: 0.5rem;
            }
            
            .login-header {
                padding: 1.5rem 1rem;
            }
            
            .login-header h1 {
                font-size: 1.5rem;
            }
            
            .login-body {
                padding: 1.5rem 1rem;
            }
            
            .login-type-btn {
                font-size: 0.7rem;
                padding: 0.6rem 0.3rem;
                flex-direction: column;
            }
            
            .form-label {
                font-size: 0.75rem;
            }
            
            .form-input {
                font-size: 0.9rem;
                padding: 0.75rem;
            }
            
            .btn-primary, .btn-secondary {
                padding: 0.875rem;
                font-size: 0.875rem;
            }
            
            .demo-info {
                display: none;
            }
            
            .back-home {
                position: static;
                display: block;
                margin: 0 auto 1rem;
                text-align: center;
                background: rgba(255, 255, 255, 0.95);
                color: #3b82f6;
                max-width: 200px;
            }
        }
        
        /* Standard phones (375px - 767px) */
        @media (min-width: 375px) and (max-width: 767px) {
            .login-page {
                padding: 1rem;
            }
            
            .login-header {
                padding: 1.75rem 1.5rem;
            }
            
            .login-body {
                padding: 1.75rem 1.5rem;
            }
            
            .login-type-btn {
                font-size: 0.8rem;
                padding: 0.7rem 0.5rem;
            }
            
            .demo-info {
                font-size: 0.65rem;
                padding: 0.75rem;
                max-width: 280px;
            }
            
            .back-home {
                font-size: 0.8rem;
                padding: 0.4rem 0.8rem;
            }
        }
        
        /* Tablets (768px - 1023px) */
        @media (min-width: 768px) and (max-width: 1023px) {
            .login-container {
                max-width: 500px;
            }
            
            .login-header {
                padding: 2.5rem;
            }
            
            .login-body {
                padding: 2.5rem;
            }
            
            .demo-info {
                font-size: 0.75rem;
                max-width: 350px;
            }
        }
        
        /* Desktop (1024px+) */
        @media (min-width: 1024px) {
            .login-container {
                max-width: 450px;
            }
            
            .login-page {
                padding: 2rem;
            }
        }
        
        /* Landscape orientation on phones */
        @media (max-height: 500px) and (orientation: landscape) {
            .login-page {
                padding: 0.5rem;
            }
            
            .login-header {
                padding: 1rem 2rem;
            }
            
            .login-header h1 {
                font-size: 1.5rem;
                margin-bottom: 0.5rem;
            }
            
            .login-body {
                padding: 1rem 2rem;
            }
            
            .form-group {
                margin-bottom: 1rem;
            }
            
            .login-type-selector {
                margin-bottom: 1rem;
            }
            
            .demo-info {
                display: none;
            }
        }
        
        /* iPad Pro and larger tablets */
        @media (min-width: 1024px) and (min-height: 1366px) {
            .login-container {
                max-width: 500px;
            }
            
            .login-header {
                padding: 3rem;
            }
            
            .login-header h1 {
                font-size: 2.5rem;
            }
            
            .login-body {
                padding: 3rem;
            }
        }
        
        /* Prevent zoom on input focus on iOS */
        @supports (-webkit-touch-callout: none) {
            .form-input {
                font-size: 16px;
            }
        }
        
        /* Loading spinner */
        @keyframes spin {
            0% { transform: rotate(0deg); }
            100% { transform: rotate(360deg); }
        }
        
        .spinner {
            border: 3px solid #f3f3f3;
            border-top: 3px solid #3498db;
            border-radius: 50%;
            width: 40px;
            height: 40px;
            animation: spin 1s linear infinite;
            margin: 0 auto;
        }
        
        /* Safe area insets for iPhone X+ */
        @supports (padding: max(0px)) {
            .login-page {
                padding-left: max(1rem, env(safe-area-inset-left));
                padding-right: max(1rem, env(safe-area-inset-right));
                padding-top: max(1rem, env(safe-area-inset-top));
                padding-bottom: max(1rem, env(safe-area-inset-bottom));
            }
        }