:root {
            --card-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
            --border-radius: 16px;
        }

        body {
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            min-height: 100vh;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            display: flex;
            align-items: center;
            justify-content: center;
            position: relative;
        }

        .register-container {
            background: rgba(255, 255, 255, 0.95);
            backdrop-filter: blur(20px);
            border-radius: var(--border-radius);
            box-shadow: var(--card-shadow);
            border: 1px solid rgba(255, 255, 255, 0.2);
            padding: 3rem;
            width: 100%;
            max-width: 500px;
            position: relative;
            z-index: 1;
            animation: slideUp 0.8s ease-out;
        }

        @keyframes slideUp {
            from { opacity: 0; transform: translateY(30px); }
            to { opacity: 1; transform: translateY(0); }
        }

        .logo-section {
            text-align: center;
            margin-bottom: 2rem;
        }

        .logo-icon {
            width: 80px;
            height: 80px;
            background: var(--primary-gradient);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 1rem;
            color: white;
            font-size: 2rem;
            box-shadow: 0 10px 25px rgba(102, 126, 234, 0.3);
        }

        .form-control {
            border-radius: 12px;
            border: 2px solid #e9ecef;
            padding: 0.75rem 1rem;
            font-size: 1rem;
            transition: var(--transition);
            background: rgba(255, 255, 255, 0.8);
            backdrop-filter: blur(10px);
        }

        .form-control:focus {
            border-color: #667eea;
            box-shadow: 0 0 0 0.2rem rgba(102, 126, 234, 0.25);
            background: white;
        }

        .input-group {
            position: relative;
            margin-bottom: 1.5rem;
        }

        .input-group .form-control {
            padding-left: 3rem;
        }

        .input-icon {
            position: absolute;
            left: 1rem;
            top: 50%;
            transform: translateY(-50%);
            color: #6c757d;
            z-index: 3;
            transition: var(--transition);
        }

        .input-group:focus-within .input-icon {
            color: #667eea;
        }

        .btn-primary {
            background: var(--primary-gradient);
            border: none;
            border-radius: 12px;
            padding: 0.75rem 2rem;
            font-weight: 600;
            font-size: 1rem;
            transition: var(--transition);
            box-shadow: 0 8px 20px rgba(102, 126, 234, 0.3);
        }

        .btn-primary:hover {
            transform: translateY(-2px);
            box-shadow: 0 12px 30px rgba(102, 126, 234, 0.4);
        }

        .theme-toggle, .lang-toggle {
            position: absolute;
            top: 1rem;
            background: rgba(255, 255, 255, 0.2);
            border: none;
            border-radius: 50%;
            width: 50px;
            height: 50px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            font-size: 1.2rem;
            transition: var(--transition);
            backdrop-filter: blur(10px);
        }

        .theme-toggle {
            right: 1rem;
        }

        .lang-toggle {
            right: 4.5rem;
        }

        .theme-toggle:hover, .lang-toggle:hover {
            background: rgba(255, 255, 255, 0.3);
        }

        .password-strength {
            margin-top: 0.5rem;
            font-size: 0.875rem;
        }

        .strength-weak { color: #dc3545; }
        .strength-medium { color: #ffc107; }
        .strength-strong { color: #28a745; }

        .loading-spinner {
            display: none;
            width: 20px;
            height: 20px;
            border: 2px solid transparent;
            border-top: 2px solid currentColor;
            border-radius: 50%;
            animation: spin 1s linear infinite;
        }

        @keyframes spin {
            0% { transform: rotate(0deg); }
            100% { transform: rotate(360deg); }
        }

        [data-theme="dark"] body {
            background: linear-gradient(135deg, #1a202c 0%, #2d3748 100%);
        }

        [data-theme="dark"] .register-container {
            background: rgba(26, 32, 44, 0.95);
            color: #e2e8f0;
        }

        [data-theme="dark"] .text-muted {
            --bs-text-opacity: 1;
            color: #e2e8f0 !important;
        }

        [data-theme="dark"] .form-control {
            background: rgba(45, 55, 72, 0.8);
            border-color: #4a5568;
            color: #e2e8f0;
        }

        [data-theme="dark"] .form-control:focus {
            background: #2d3748;
        }