body {
            background: linear-gradient(rgba(28, 25, 22, 0.55), rgba(28, 25, 22, 0.72)), 
                        url('https://collegeinfogeek.com/wp-content/uploads/2018/11/Essential-Books.jpg');
            background-size: cover;
            background-position: center;
            background-attachment: fixed;
            min-height: 100vh;
            display: flex;
            align-items: center;
            justify-content: center;
        }
        
        .login-container {
            background: var(--ch-surface);
            border-radius: var(--bs-border-radius);
            box-shadow: var(--ch-shadow-2);
            padding: 40px;
            width: 100%;
            max-width: 400px;
        }
        
        .login-header {
            text-align: center;
            margin-bottom: 30px;
        }
        
        .login-header h1 {
            color: var(--ch-text-heading);
            font-weight: bold;
            margin-bottom: 10px;
        }
        
        .login-header p {
            color: var(--ch-text-muted);
            margin: 0;
        }
        
        .form-control {
            border-radius: var(--bs-border-radius);
            border: 1px solid var(--ch-border);
            padding: 12px 15px;
            transition: all 0.3s ease;
        }
        
        .form-control:focus {
            border-color: var(--primary-accent);
            box-shadow: 0 0 0 0.2rem var(--ch-accent-focus);
        }
        
        .btn-login {
            background: var(--primary-accent);
            border: none;
            border-radius: var(--bs-border-radius);
            padding: 12px;
            font-weight: 600;
            transition: all 0.3s ease;
        }
        
        .btn-login:hover {
            transform: translateY(-2px);
            box-shadow: 0 8px 25px var(--ch-accent-focus);
        }
        
        .input-group-text {
            background: #f8f9fa;
            border: 1px solid var(--ch-border);
            border-right: none;
            border-radius: var(--bs-border-radius) 0 0 var(--bs-border-radius);
        }
        
        .input-group .form-control {
            border-left: none;
            border-radius: 0 10px 10px 0;
        }
        
        .alert {
            border-radius: var(--bs-border-radius);
            border: none;
        }
        
        .loading {
            display: none;
        }
        
        .loading.show {
            display: block;
        }
        
        .spinner-border-sm {
            width: 1rem;
            height: 1rem;
        }
        
        .footer-links {
            text-align: center;
            margin-top: 20px;
        }
        
        .footer-links a {
            color: var(--primary-accent);
            text-decoration: none;
            font-size: 0.9em;
        }
        
        .footer-links a:hover {
            text-decoration: underline;
        }

        .login-theme-toggle {
            position: fixed;
            top: 1rem;
            right: 1rem;
            z-index: 1000;
            width: 42px;
            height: 42px;
            border-radius: 50%;
            border: none;
            background: rgba(255, 255, 255, 0.92);
            color: var(--ch-text-heading);
            box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15);
        }

        [data-bs-theme="dark"] body {
            background: linear-gradient(rgba(20, 17, 14, 0.86), rgba(20, 17, 14, 0.93)),
                        url('https://collegeinfogeek.com/wp-content/uploads/2018/11/Essential-Books.jpg');
            background-size: cover;
            background-position: center;
            background-attachment: fixed;
        }

        [data-bs-theme="dark"] .login-container {
            background: var(--ch-surface);
            color: var(--ch-text);
            border: 1px solid var(--ch-border);
        }

        [data-bs-theme="dark"] .login-header h1 {
            color: var(--ch-text-heading);
        }

        [data-bs-theme="dark"] .login-header p {
            color: var(--ch-text-muted);
        }

        [data-bs-theme="dark"] .input-group-text {
            background: var(--ch-surface-muted);
            border-color: var(--ch-border);
            color: var(--ch-text-muted);
        }

        [data-bs-theme="dark"] .form-control {
            background: var(--ch-surface-muted);
            border-color: var(--ch-border);
            color: var(--ch-text);
        }

        [data-bs-theme="dark"] .form-control:focus {
            background: var(--ch-surface-muted);
            border-color: var(--primary-accent);
            box-shadow: 0 0 0 0.2rem var(--ch-accent-focus);
            color: var(--ch-text);
        }

        [data-bs-theme="dark"] .footer-links a {
            color: var(--primary-accent);
        }

        [data-bs-theme="dark"] .login-theme-toggle {
            background: var(--ch-surface-muted);
            color: var(--ch-text);
            border: 1px solid var(--ch-border);
            box-shadow: 0 4px 16px rgba(1, 4, 9, 0.45);
        }