:root {
            /* Light mode colors */
            --bg-primary: #ffffff;
            --bg-secondary: #f8fafc;
            --bg-gradient-start: #667eea;
            --bg-gradient-end: #764ba2;
            --body-bg-start: #ffffff;
            --body-bg-end: #667eea;
            --text-primary: #1a1a1a;
            --text-secondary: #6b7280;
            --text-heading: #1f2937;
            --accent-primary: #667eea;
            --accent-hover: #5a67d8;
            --card-bg: #ffffff;
            --border-color: #e5e7eb;
            --input-bg: #f9fafb;
            --input-focus-bg: #ffffff;
            --shadow-color: rgba(0, 0, 0, 0.15);
            --overlay-bg: rgba(255, 255, 255, 0.95);
            --brand-text: #ffffff;
        }

        [data-theme="dark"] {
            /* Dark mode colors */
            --bg-primary: #000000;
            --bg-secondary: #111111;
            --bg-gradient-start: #000000;
            --bg-gradient-end: #1a1a1a;
            --body-bg-start: #000000;
            --body-bg-end: #1a1a1a;
            --text-primary: #ffffff;
            --text-secondary: #d1d5db;
            --text-heading: #ffffff;
            --accent-primary: #fbbf24;
            --accent-hover: #f59e0b;
            --card-bg: #111111;
            --border-color: #333333;
            --input-bg: #1a1a1a;
            --input-focus-bg: #222222;
            --shadow-color: rgba(251, 191, 36, 0.15);
            --overlay-bg: rgba(0, 0, 0, 0.95);
            --brand-text: #fbbf24;
        }

        /* Reset and base styles */
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        body {
            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
            background: linear-gradient(135deg, var(--body-bg-start) 0%, var(--body-bg-end) 100%);
            color: var(--text-primary);
            line-height: 1.6;
            min-height: 100vh;
            display: flex;
            align-items: center;
            justify-content: center;
            padding: 1rem;
            transition: background 0.3s ease, color 0.3s ease;
        }

        .login-container {
            width: 100%;
            max-width: 1000px;
            background: var(--card-bg);
            border-radius: 24px;
            box-shadow: 0 20px 60px var(--shadow-color);
            overflow: hidden;
            animation: slideUp 0.6s ease-out;
            display: flex;
            min-height: 600px;
        }

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

        /* Split-screen branding side */
        .login-brand {
            flex: 1;
            background: linear-gradient(135deg, var(--bg-gradient-start) 0%, var(--bg-gradient-end) 100%);
            display: flex;
            flex-direction: column;
            justify-content: center;
            align-items: center;
            padding: 3rem 2rem;
            text-align: center;
            position: relative;
            overflow: hidden;
        }

        .login-brand::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: radial-gradient(circle at 30% 20%, rgba(255, 255, 255, 0.1) 0%, transparent 50%),
                        radial-gradient(circle at 80% 80%, rgba(255, 255, 255, 0.08) 0%, transparent 50%);
        }

        .brand-content {
            position: relative;
            z-index: 2;
            color: var(--brand-text);
        }

        .brand-logo {
            font-size: 3rem;
            font-weight: 800;
            margin-bottom: 1rem;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 1rem;
        }

        .brand-tagline {
            font-size: 1.25rem;
            opacity: 0.9;
            margin-bottom: 2rem;
            line-height: 1.5;
        }

        .brand-features {
            display: flex;
            flex-direction: column;
            gap: 1rem;
            opacity: 0.8;
        }

        .brand-feature {
            display: flex;
            align-items: center;
            gap: 0.75rem;
            font-size: 0.95rem;
        }

        .brand-feature i {
            width: 20px;
            text-align: center;
        }

        /* Form side */
        .login-form-side {
            flex: 1;
            display: flex;
            flex-direction: column;
            justify-content: center;
            padding: 3rem 2.5rem;
            background: var(--card-bg);
            transition: background-color 0.3s ease;
        }

        .form-header {
            text-align: center;
            margin-bottom: 2rem;
        }

        .form-title {
            font-size: 1.875rem;
            font-weight: 700;
            color: var(--text-heading);
            margin-bottom: 0.5rem;
        }

        .form-subtitle {
            color: var(--text-secondary);
            font-size: 0.95rem;
        }

        /* Theme toggle button */
        .theme-toggle {
            position: absolute;
            top: 1.5rem;
            right: 1.5rem;
            background: rgba(255, 255, 255, 0.2);
            border: 2px solid rgba(255, 255, 255, 0.3);
            color: var(--brand-text);
            padding: 0.5rem;
            border-radius: 8px;
            cursor: pointer;
            font-size: 1rem;
            transition: all 0.2s ease;
            z-index: 10;
        }

        .theme-toggle:hover {
            background: rgba(255, 255, 255, 0.3);
            transform: scale(1.05);
        }

        .theme-toggle:active {
            transform: scale(0.95);
        }

        .form-group {
            margin-bottom: 1.5rem;
        }

        .form-label {
            display: block;
            font-size: 0.875rem;
            font-weight: 600;
            color: var(--text-heading);
            margin-bottom: 0.5rem;
        }

        .form-input {
            width: 100%;
            padding: 1rem 1.25rem;
            border: 2px solid var(--border-color);
            border-radius: 12px;
            font-size: 1rem;
            background: var(--input-bg);
            color: var(--text-heading);
            transition: all 0.2s ease;
        }

        .form-input:focus {
            outline: none;
            border-color: var(--accent-primary);
            background: var(--input-focus-bg);
            box-shadow: 0 0 0 3px var(--shadow-color);
        }

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

        .input-icon {
            position: relative;
        }

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

        .input-icon .icon {
            position: absolute;
            left: 1rem;
            top: 50%;
            transform: translateY(-50%);
            color: var(--text-secondary);
            font-size: 1rem;
            pointer-events: none;
            transition: color 0.2s ease;
        }

        .input-icon .form-input:focus + .icon,
        .input-icon:focus-within .icon {
            color: var(--accent-primary);
        }

        .password-toggle {
            position: absolute;
            right: 1rem;
            top: 50%;
            transform: translateY(-50%);
            background: none;
            border: none;
            color: var(--text-secondary);
            font-size: 1rem;
            cursor: pointer;
            padding: 0.25rem;
            border-radius: 4px;
            transition: color 0.2s ease;
        }

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

        .password-toggle:focus {
            outline: 2px solid var(--accent-primary);
            outline-offset: 2px;
        }

        .form-options {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 2rem;
            font-size: 0.875rem;
        }

        .remember-me {
            display: flex;
            align-items: center;
            gap: 0.5rem;
            cursor: pointer;
        }

        .remember-me input[type="checkbox"] {
            width: 1rem;
            height: 1rem;
            border: 2px solid #d1d5db;
            border-radius: 4px;
            background: white;
            cursor: pointer;
        }

        .remember-me input[type="checkbox"]:checked {
            background: var(--accent-primary);
            border-color: var(--accent-primary);
        }

        .forgot-link {
            color: var(--accent-primary);
            text-decoration: none;
            font-weight: 500;
            transition: color 0.2s ease;
        }

        .forgot-link:hover {
            color: var(--accent-hover);
            text-decoration: underline;
        }

        .login-btn {
            width: 100%;
            background: var(--accent-primary);
            color: var(--bg-primary);
            padding: 1.25rem;
            border: none;
            border-radius: 12px;
            font-size: 1rem;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.2s ease;
            margin-bottom: 1.5rem;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 0.5rem;
        }

        .login-btn:hover {
            background: var(--accent-hover);
            transform: translateY(-1px);
            box-shadow: 0 4px 12px var(--shadow-color);
        }

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

        .divider {
            text-align: center;
            position: relative;
            margin: 2rem 0;
            color: var(--text-secondary);
            font-size: 0.875rem;
        }

        .divider::before {
            content: '';
            position: absolute;
            top: 50%;
            left: 0;
            right: 0;
            height: 1px;
            background: var(--border-color);
        }

        .divider span {
            background: var(--card-bg);
            padding: 0 1rem;
        }

        .signup-link {
            text-align: center;
            color: var(--text-secondary);
            font-size: 0.95rem;
        }

        .signup-link a {
            color: var(--accent-primary);
            text-decoration: none;
            font-weight: 600;
            margin-left: 0.25rem;
        }

        .signup-link a:hover {
            color: var(--accent-hover);
            text-decoration: underline;
        }

        .error-message {
            background: #fef2f2;
            border: 1px solid #fecaca;
            border-radius: 8px;
            padding: 0.75rem 1rem;
            margin-bottom: 1.5rem;
            color: #dc2626;
            font-size: 0.875rem;
        }

        /* Dark mode specific overrides */
        [data-theme="dark"] .error-message {
            background: rgba(239, 68, 68, 0.1);
            border-color: rgba(239, 68, 68, 0.3);
            color: #fca5a5;
        }

        [data-theme="dark"] .remember-me input[type="checkbox"] {
            background: var(--input-bg);
            border-color: var(--border-color);
        }

        [data-theme="dark"] .divider::before {
            background: var(--border-color);
        }

        /* Back to home link */
        .back-link {
            position: absolute;
            top: 1rem;
            left: 1rem;
            color: rgba(255, 255, 255, 0.8);
            text-decoration: none;
            font-size: 0.875rem;
            font-weight: 500;
            display: flex;
            align-items: center;
            gap: 0.5rem;
            transition: color 0.2s ease;
            z-index: 100;
            background: rgba(0, 0, 0, 0.5);
            padding: 0.5rem 0.75rem;
            border-radius: 8px;
            backdrop-filter: blur(10px);
        }

        .back-link:hover {
            color: white;
            text-decoration: none;
            background: rgba(0, 0, 0, 0.7);
        }

        @media (max-width: 480px) {
            .back-link {
                position: fixed;
                top: 1rem;
                left: 1rem;
                background: rgba(0, 0, 0, 0.5);
                padding: 0.5rem 0.75rem;
                border-radius: 8px;
                backdrop-filter: blur(10px);
            }
        }

        /* Mobile Responsive - Hide branding on small screens */
        @media (max-width: 768px) {
            .login-container {
                max-width: 400px;
                flex-direction: column;
                min-height: auto;
            }

            .login-brand {
                display: none;
            }

            .login-form-side {
                padding: 2.5rem 2rem;
            }

            .back-link {
                position: fixed;
                top: 1rem;
                left: 1rem;
                background: rgba(0, 0, 0, 0.8);
                padding: 0.5rem 0.75rem;
                border-radius: 8px;
                backdrop-filter: blur(10px);
                z-index: 100;
            }
        }

        @media (max-width: 480px) {
            body {
                padding: 0.5rem;
            }

            .login-container {
                border-radius: 16px;
                max-width: none;
            }

            .login-form-side {
                padding: 2rem 1.5rem;
            }

            .form-options {
                flex-direction: column;
                gap: 1rem;
                align-items: stretch;
                text-align: center;
            }

            .theme-toggle {
                top: 1rem;
                right: 1rem;
            }
        }