:root {
            --color-primary: #213A8C;
            --color-primary-dark: #162A63;
            --color-accent: #2EB26B;
            --color-danger: #EF4444;
            --color-warning: #F59E0B;
            --color-muted-blue: #7E8EB8;
            --color-surface: #FFFFFF;
            --color-page-bg: #F6F7FB;
            --color-lavender-tint: #F0F2FB;
            --color-soft-pink: #F5D3E0;
            --color-text-primary: #10203A;
            --color-text-secondary: #6B7280;
            --color-border: #E6E9F2;
            --font-family: 'Poppins', 'Inter', system-ui, sans-serif;
            --radius-sm: 8px;
            --radius-md: 16px;
            --radius-lg: 24px;
            --radius-xl: 48px;
            --radius-huge: 56px;
            --elevation-low: 0 2px 8px rgba(33, 58, 140, 0.06);
            --elevation-medium: 0 12px 30px rgba(33, 58, 140, 0.06);
            --elevation-floating: 0 18px 40px rgba(46, 178, 107, 0.18);
        }

        * {
            -webkit-tap-highlight-color: transparent;
        }

        body {
            font-family: var(--font-family);
            background-color: var(--color-page-bg);
            margin: 0;
            padding: 0;
            min-height: 100vh;
            display: flex;
            align-items: center;
            justify-content: center;
        }

        /* Main container */
        .signup-container {
            width: 100%;
            max-width: 520px;
            padding: 20px;
            margin: 0 auto;
        }

        /* Card styling */
        .signup-card {
            background: var(--color-surface);
            border-radius: var(--radius-xl);
            padding: 40px 32px;
            box-shadow: var(--elevation-medium);
            text-align: center;
        }

        /* Logo/Brand area */
        .brand-section {
            margin-bottom: 40px;
        }

        .brand-icon {
            width: 72px;
            height: 72px;
            background: var(--color-accent);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 20px;
            color: white;
            font-size: 32px;
        }

        .brand-title {
            font-size: 28px;
            font-weight: 800;
            color: var(--color-text-primary);
            margin-bottom: 8px;
        }

        .brand-subtitle {
            font-size: 16px;
            color: var(--color-text-secondary);
            font-weight: 400;
        }

        /* Form styling */
        .signup-form {
            text-align: left;
        }

        .form-row {
            display: flex;
            gap: 16px;
            margin-bottom: 24px;
        }

        .form-group {
            margin-bottom: 24px;
            flex: 1;
        }

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

        .form-input {
            width: 100%;
            background: var(--color-lavender-tint);
            border: 2px solid transparent;
            border-radius: var(--radius-md);
            padding: 16px;
            font-size: 16px;
            font-family: var(--font-family);
            color: var(--color-text-primary);
            transition: all 0.2s ease;
            box-sizing: border-box;
        }

        .form-input:focus {
            outline: none;
            border-color: var(--color-primary);
            background: var(--color-surface);
            box-shadow: 0 0 0 4px rgba(33, 58, 140, 0.1);
        }

        .form-input::placeholder {
            color: var(--color-text-secondary);
        }

        .form-input.error {
            border-color: var(--color-danger);
            background: #FFF5F5;
        }

        .form-input.success {
            border-color: var(--color-accent);
            background: #F0FDF4;
        }

        .form-input.warning {
            border-color: var(--color-warning);
            background: #FFFBEB;
        }

        /* Password input with toggle */
        .password-input-container {
            position: relative;
        }

        .password-toggle {
            position: absolute;
            right: 16px;
            top: 50%;
            transform: translateY(-50%);
            background: none;
            border: none;
            color: var(--color-muted-blue);
            cursor: pointer;
            font-size: 16px;
            padding: 4px;
            transition: color 0.2s ease;
        }

        .password-toggle:hover {
            color: var(--color-primary);
        }

        /* Password strength indicator */
        .password-strength {
            margin-top: 8px;
            display: none;
        }

        .password-strength.show {
            display: block;
        }

        .strength-bar {
            height: 4px;
            background: var(--color-border);
            border-radius: 2px;
            overflow: hidden;
            margin-bottom: 8px;
        }

        .strength-fill {
            height: 100%;
            width: 0%;
            background: var(--color-danger);
            transition: all 0.3s ease;
            border-radius: 2px;
        }

        .strength-fill.weak {
            width: 25%;
            background: var(--color-danger);
        }

        .strength-fill.fair {
            width: 50%;
            background: var(--color-warning);
        }

        .strength-fill.good {
            width: 75%;
            background: var(--color-accent);
        }

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

        .strength-text {
            font-size: 12px;
            color: var(--color-text-secondary);
        }

        /* Error message */
        .error-message {
            margin-top: 8px;
            font-size: 13px;
            color: var(--color-danger);
            display: none;
        }

        .error-message.show {
            display: block;
        }

        /* Success message */
        .success-message {
            margin-top: 8px;
            font-size: 13px;
            color: var(--color-accent);
            display: none;
        }

        .success-message.show {
            display: block;
        }

        /* Submit button */
        .submit-button {
            width: 100%;
            background: var(--color-accent);
            color: white;
            border: none;
            border-radius: var(--radius-md);
            padding: 18px;
            font-size: 16px;
            font-weight: 600;
            font-family: var(--font-family);
            cursor: pointer;
            transition: all 0.2s ease;
            margin-bottom: 24px;
            box-shadow: var(--elevation-floating);
        }

        .submit-button:hover {
            background: #25A55A;
            transform: translateY(-1px);
            box-shadow: 0 20px 45px rgba(46, 178, 107, 0.25);
        }

        .submit-button:active {
            transform: scale(0.98);
        }

        .submit-button:disabled {
            background: var(--color-muted-blue);
            cursor: not-allowed;
            transform: none;
            box-shadow: var(--elevation-low);
        }

        /* Loading state */
        .submit-button.loading {
            position: relative;
            color: transparent;
        }

        .submit-button.loading::after {
            content: '';
            position: absolute;
            top: 50%;
            left: 50%;
            transform: translate(-50%, -50%);
            width: 20px;
            height: 20px;
            border: 2px solid rgba(255, 255, 255, 0.3);
            border-top: 2px solid white;
            border-radius: 50%;
            animation: spin 1s linear infinite;
        }

        @keyframes spin {
            0% { transform: translate(-50%, -50%) rotate(0deg); }
            100% { transform: translate(-50%, -50%) rotate(360deg); }
        }

        /* Terms checkbox */
        .checkbox-group {
            display: flex;
            align-items: flex-start;
            margin-bottom: 24px;
            gap: 12px;
        }

        .checkbox-input {
            width: 18px;
            height: 18px;
            margin-top: 2px;
            accent-color: var(--color-accent);
            flex-shrink: 0;
        }

        .checkbox-label {
            font-size: 14px;
            color: var(--color-text-secondary);
            cursor: pointer;
            line-height: 1.5;
        }

        .checkbox-label a {
            color: var(--color-primary);
            text-decoration: none;
            font-weight: 500;
        }

        .checkbox-label a:hover {
            text-decoration: underline;
        }

        /* Links */
        .form-links {
            text-align: center;
            margin-top: 24px;
        }

        .form-link {
            color: var(--color-primary);
            text-decoration: none;
            font-size: 14px;
            font-weight: 500;
            transition: color 0.2s ease;
        }

        .form-link:hover {
            color: var(--color-primary-dark);
            text-decoration: underline;
        }

        /* Social signup section */
        .social-signup {
            margin-top: 32px;
            padding-top: 32px;
            border-top: 1px solid var(--color-border);
        }

        .social-signup-title {
            text-align: center;
            margin-bottom: 20px;
            font-size: 14px;
            color: var(--color-text-secondary);
            font-weight: 500;
        }

        .social-button {
            width: 100%;
            background: var(--color-surface);
            border: 2px solid var(--color-border);
            border-radius: var(--radius-md);
            padding: 14px;
            font-size: 15px;
            font-weight: 500;
            font-family: var(--font-family);
            cursor: pointer;
            transition: all 0.2s ease;
            display: flex;
            align-items: center;
            justify-content: center;
            margin-bottom: 12px;
            color: var(--color-text-primary);
        }

        .social-button:hover {
            border-color: var(--color-primary);
            background: var(--color-lavender-tint);
        }

        .social-button:active {
            transform: scale(0.98);
        }

        .social-button i {
            margin-right: 12px;
            font-size: 18px;
        }

        .social-button.google i {
            color: #4285F4;
        }

        .social-button.microsoft i {
            color: #0078D4;
        }

        /* Responsive design */
        @media (max-width: 580px) {
            .signup-container {
                padding: 16px;
            }

            .signup-card {
                padding: 32px 24px;
            }

            .brand-title {
                font-size: 24px;
            }

            .form-row {
                flex-direction: column;
                gap: 0;
            }

            .form-input {
                padding: 14px;
                font-size: 16px; /* Prevent zoom on iOS */
            }

            .submit-button {
                padding: 16px;
            }
        }

        /* Touch improvements */
        @media (hover: none) and (pointer: coarse) {
            .form-input {
                font-size: 16px; /* Prevent zoom on mobile */
            }
        }

        /* Safe area handling */
        @supports (padding: max(0px)) {
            body {
                padding-top: max(20px, env(safe-area-inset-top));
                padding-bottom: max(20px, env(safe-area-inset-bottom));
            }
        }

        /* High contrast mode support */
        @media (prefers-contrast: high) {
            .form-input {
                border: 2px solid var(--color-text-secondary);
            }

            .form-input:focus {
                border-color: var(--color-primary);
            }
        }

        /* Reduced motion support */
        @media (prefers-reduced-motion: reduce) {
            * {
                animation-duration: 0.01ms !important;
                animation-iteration-count: 1 !important;
                transition-duration: 0.01ms !important;
            }
        }