:root {
            --primary: #4a6cf7;
            --primary-dark: #3a5ce5;
            --secondary: #6c757d;
            --success: #28a745;
            --danger: #dc3545;
            --warning: #ffc107;
            --light: #f8f9fa;
            --dark: #343a40;
            --border: #dee2e6;
            --shadow: 0 10px 30px rgba(0,0,0,0.1);
            --gradient: linear-gradient(135deg, #4a6cf7 0%, #6a11cb 100%);
        }

        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }

        body {
            background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
            min-height: 100vh;
            display: flex;
            flex-direction: column;
        }

        .auth-section {
            flex: 1;
            display: flex;
            align-items: center;
            justify-content: center;
            padding: 40px 20px;
        }

        .auth-container {
            background: white;
            border-radius: 20px;
            box-shadow: var(--shadow);
            overflow: hidden;
            width: 100%;
            max-width: 480px;
            transition: transform 0.3s ease;
        }

        .auth-container:hover {
            transform: translateY(-5px);
        }

        .auth-header {
            background: var(--gradient);
            color: white;
            padding: 30px;
            text-align: center;
        }

        .auth-header h2 {
            font-size: 28px;
            font-weight: 700;
            margin-bottom: 8px;
        }

        .auth-header p {
            opacity: 0.9;
            font-size: 16px;
        }

        .auth-body {
            padding: 40px;
        }

        .form-group {
            margin-bottom: 24px;
            position: relative;
        }

        .form-group label {
            display: block;
            margin-bottom: 8px;
            font-weight: 600;
            color: var(--dark);
            font-size: 14px;
        }

        .form-control {
            width: 100%;
            padding: 14px 16px;
            border: 2px solid var(--border);
            border-radius: 12px;
            font-size: 16px;
            transition: all 0.3s ease;
            background: var(--light);
        }

        .form-control:focus {
            border-color: var(--primary);
            background: white;
            box-shadow: 0 0 0 3px rgba(74, 108, 247, 0.1);
            outline: none;
        }

        .form-control.has-error {
            border-color: var(--danger);
        }

        .form-row {
            display: flex;
            gap: 15px;
        }

        .form-row .form-group {
            flex: 1;
        }

        .phone-group {
            display: flex;
            gap: 12px;
        }

        .phone-group .country-code {
            width: 120px;
            flex-shrink: 0;
        }

        .phone-group .phone-number {
            flex: 1;
        }

        .country-code-hint {
            font-size: 12px;
            color: var(--secondary);
            margin-top: 6px;
        }

        .gender-group {
            display: flex;
            gap: 12px;
            background: var(--light);
            padding: 4px;
            border-radius: 12px;
        }

        .gender-option {
            flex: 1;
            text-align: center;
        }

        .gender-option input {
            display: none;
        }

        .gender-option label {
            display: block;
            padding: 12px;
            border-radius: 8px;
            cursor: pointer;
            transition: all 0.3s ease;
            margin: 0;
            font-weight: 500;
        }

        .gender-option input:checked + label {
            background: white;
            color: var(--primary);
            box-shadow: 0 2px 8px rgba(0,0,0,0.1);
        }

        .btn-auth {
            width: 100%;
            padding: 16px;
            background: var(--gradient);
            color: white;
            border: none;
            border-radius: 12px;
            font-size: 16px;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s ease;
            margin-top: 10px;
        }

        .btn-auth:hover {
            transform: translateY(-2px);
            box-shadow: 0 5px 15px rgba(74, 108, 247, 0.4);
        }

        .btn-auth:active {
            transform: translateY(0);
        }

        .auth-links {
            text-align: center;
            margin-top: 30px;
            color: var(--secondary);
        }

        .auth-links a {
            color: var(--primary);
            text-decoration: none;
            font-weight: 600;
            transition: color 0.3s ease;
        }

        .auth-links a:hover {
            color: var(--primary-dark);
            text-decoration: underline;
        }

        .alert {
            padding: 16px;
            border-radius: 12px;
            margin-bottom: 24px;
            font-weight: 500;
            display: flex;
            align-items: center;
            gap: 12px;
        }

        .alert-error {
            background: #ffeaea;
            color: var(--danger);
            border: 1px solid #ffcdd2;
        }

        .alert-success {
            background: #e8f5e8;
            color: var(--success);
            border: 1px solid #c8e6c9;
        }

        .alert i {
            font-size: 20px;
        }

        .password-strength {
            margin-top: 8px;
            font-size: 13px;
            display: flex;
            align-items: center;
            gap: 8px;
        }

        .strength-bar {
            flex: 1;
            height: 4px;
            background: var(--border);
            border-radius: 2px;
            overflow: hidden;
        }

        .strength-fill {
            height: 100%;
            transition: all 0.3s ease;
            border-radius: 2px;
        }

        .strength-weak .strength-fill {
            width: 33%;
            background: var(--danger);
        }

        .strength-medium .strength-fill {
            width: 66%;
            background: var(--warning);
        }

        .strength-strong .strength-fill {
            width: 100%;
            background: var(--success);
        }

        .strength-weak { color: var(--danger); }
        .strength-medium { color: var(--warning); }
        .strength-strong { color: var(--success); }

        .input-icon {
            position: relative;
        }

        .input-icon i {
            position: absolute;
            left: 16px;
            top: 50%;
            transform: translateY(-50%);
            color: var(--secondary);
        }

        .input-icon .form-control {
            padding-left: 45px;
        }

        .password-toggle {
            position: absolute;
            right: 16px;
            top: 50%;
            transform: translateY(-50%);
            background: none;
            border: none;
            color: var(--secondary);
            cursor: pointer;
        }

        @media (max-width: 576px) {
            .auth-body {
                padding: 30px 20px;
            }
            
            .form-row {
                flex-direction: column;
                gap: 0;
            }
            
            .phone-group {
                flex-direction: column;
            }
            
            .phone-group .country-code {
                width: 100%;
            }
        }

        .loading {
            display: inline-block;
            width: 20px;
            height: 20px;
            border: 3px solid rgba(255,255,255,.3);
            border-radius: 50%;
            border-top-color: #fff;
            animation: spin 1s ease-in-out infinite;
        }

        @keyframes spin {
            to { transform: rotate(360deg); }
        }