:root {
            --primary-color: #6366f1;
            --primary-hover: #5b5de8;
            --primary-light: #f0f0ff;
            --secondary-color: #64748b;
            --accent-color: #06b6d4;
            --error-color: #ef4444;
            --success-color: #10b981;
            --warning-color: #f59e0b;
            --dark-color: #1e293b;
            --light-color: #f8fafc;
            --border-color: #e2e8f0;
            --shadow-color: rgba(0, 0, 0, 0.1);
            --shadow-hover: rgba(0, 0, 0, 0.15);
            --gradient-bg: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
        }
        
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        
        body {
            font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
            background: var(--gradient-bg);
            min-height: 100vh;
            display: flex;
            align-items: center;
            justify-content: center;
            padding: 20px;
            position: relative;
            overflow-x: hidden;
        }
        
        /* Animated background particles */
        body::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background-image: 
                radial-gradient(circle at 25% 25%, rgba(255,255,255,0.1) 0%, transparent 50%),
                radial-gradient(circle at 75% 75%, rgba(255,255,255,0.1) 0%, transparent 50%);
            animation: float 20s ease-in-out infinite;
        }
        
        @keyframes float {
            0%, 100% { transform: translateY(0px); }
            50% { transform: translateY(-20px); }
        }
        
        .container {
            background: rgba(255, 255, 255, 0.95);
            backdrop-filter: blur(20px);
            padding: 40px;
            border-radius: 24px;
            box-shadow: 
                0 20px 40px rgba(0,0,0,0.1),
                0 1px 3px rgba(0,0,0,0.05);
            border: 1px solid rgba(255, 255, 255, 0.2);
            max-width: 450px;
            width: 100%;
            position: relative;
            z-index: 1;
            animation: slideIn 0.6s ease-out;
        }
        
        @keyframes slideIn {
            from {
                opacity: 0;
                transform: translateY(30px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }
        
        .logo {
            text-align: center;
            margin-bottom: 32px;
        }
        
        .logo-icon {
            width: 60px;
            height: 60px;
            background: var(--gradient-bg);
            border-radius: 50%;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            margin-bottom: 16px;
            color: white;
            font-size: 24px;
            font-weight: bold;
            box-shadow: 0 8px 20px rgba(102, 102, 241, 0.3);
        }
        
        h1 {
            color: var(--dark-color);
            text-align: center;
            font-size: 28px;
            font-weight: 700;
            margin-bottom: 8px;
            letter-spacing: -0.5px;
        }
        
        .subtitle {
            color: var(--secondary-color);
            text-align: center;
            font-size: 16px;
            margin-bottom: 32px;
        }
        
        .form-group {
            margin-bottom: 24px;
            position: relative;
        }
        
        label {
            display: block;
            margin-bottom: 8px;
            font-weight: 500;
            color: var(--dark-color);
            font-size: 14px;
            letter-spacing: 0.3px;
        }
        
        .input-wrapper {
            position: relative;
        }
        
        input[type="text"], input[type="password"] {
            width: 100%;
            padding: 16px 20px;
            border: 2px solid var(--border-color);
            border-radius: 12px;
            font-size: 16px;
            background: white;
            transition: all 0.3s ease;
            color: var(--dark-color);
        }
        
        input[type="text"]:focus, input[type="password"]:focus {
            outline: none;
            border-color: var(--primary-color);
            box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
            transform: translateY(-2px);
        }
        
        .input-icon {
            position: absolute;
            right: 16px;
            top: 50%;
            transform: translateY(-50%);
            color: var(--secondary-color);
            font-size: 18px;
        }
        
        button {
            width: 100%;
            padding: 16px;
            background: var(--primary-color);
            color: white;
            border: none;
            border-radius: 12px;
            font-size: 16px;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s ease;
            position: relative;
            overflow: hidden;
        }
        
        button::before {
            content: '';
            position: absolute;
            top: 0;
            left: -100%;
            width: 100%;
            height: 100%;
            background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
            transition: left 0.5s;
        }
        
        button:hover {
            background: var(--primary-hover);
            transform: translateY(-2px);
            box-shadow: 0 10px 25px rgba(99, 102, 241, 0.3);
        }
        
        button:hover::before {
            left: 100%;
        }
        
        button:active {
            transform: translateY(0);
        }
        
        button:disabled {
            background: var(--secondary-color);
            cursor: not-allowed;
            transform: none;
            box-shadow: none;
        }
        
        .alert {
            margin: 20px 0;
            padding: 16px 20px;
            border-radius: 12px;
            font-size: 14px;
            font-weight: 500;
            display: flex;
            align-items: center;
            animation: slideDown 0.3s ease-out;
        }
        
        @keyframes slideDown {
            from {
                opacity: 0;
                transform: translateY(-10px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }
        
        .alert-icon {
            margin-right: 12px;
            font-size: 18px;
        }
        
        .error {
            color: var(--error-color);
            background: rgba(239, 68, 68, 0.1);
            border: 1px solid rgba(239, 68, 68, 0.2);
        }
        
        .success {
            color: var(--success-color);
            background: rgba(16, 185, 129, 0.1);
            border: 1px solid rgba(16, 185, 129, 0.2);
        }
        
        .loading {
            display: none;
            color: var(--primary-color);
            text-align: center;
            margin: 20px 0;
            font-weight: 500;
        }
        
        .loading-spinner {
            display: inline-block;
            width: 20px;
            height: 20px;
            border: 2px solid rgba(99, 102, 241, 0.3);
            border-radius: 50%;
            border-top-color: var(--primary-color);
            animation: spin 1s ease-in-out infinite;
            margin-right: 8px;
        }
        
        @keyframes spin {
            to { transform: rotate(360deg); }
        }
        
        /* Responsive */
        @media (max-width: 480px) {
            .container {
                padding: 24px;
                margin: 10px;
                border-radius: 16px;
            }
            
            h1 {
                font-size: 24px;
            }
            
            .subtitle {
                font-size: 14px;
            }
            
            input[type="text"], input[type="password"] {
                padding: 14px 16px;
                font-size: 16px;
            }
            
            button {
                padding: 14px;
                font-size: 15px;
            }
        }
        
        /* Dark mode support */
        @media (prefers-color-scheme: dark) {
            .container {
                background: rgba(30, 41, 59, 0.95);
                color: white;
            }
            
            h1, label {
                color: white;
            }
            
            input[type="text"], input[type="password"] {
                background: rgba(51, 65, 85, 0.8);
                border-color: rgba(148, 163, 184, 0.3);
                color: white;
            }
        }
        
        /* Shake animation for errors */
        @keyframes shake {
            0%, 100% { transform: translateX(0); }
            10%, 30%, 50%, 70%, 90% { transform: translateX(-5px); }
            20%, 40%, 60%, 80% { transform: translateX(5px); }
        }