       :root {
            --primary-dark: #1e293b;
            --secondary-dark: #334155;
            --primary-light: #f8fafc;
            --secondary-light: #e2e8f0;
            --accent-color: #3B82F6;
            --danger-color: #ef4444;
            --success-color: #10b981;
        }

        body {
            transition: all 0.3s ease;
            background-color: var(--primary-dark);
            color: var(--primary-light);
        }

        .light-mode {
            background-color: var(--primary-light);
            color: var(--primary-dark);
        }

        .card {
            background-color: var(--secondary-dark);
            border-radius: 0.5rem;
            box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
            transition: all 0.3s ease;
        }

        .light-mode .card {
            background-color: var(--secondary-light);
        }
    
        .btn-primary {
            background-color: var(--accent-color);
            color: white;
            transition: all 0.2s ease;
        }

        .btn-primary:hover {
            background-color: #2563eb;
            transform: translateY(-1px);
        }

        .btn-danger {
            background-color: var(--danger-color);
            color: white;
        }

        .btn-danger:hover {
            background-color: #dc2626;
        }

        .btn-success {
            background-color: var(--success-color);
            color: white;
        }

        .btn-success:hover {
            background-color: #059669;
        }

        .input-field {
            background-color: rgba(255, 255, 255, 0.1);
            border: 1px solid rgba(255, 255, 255, 0.2);
            color: var(--primary-light);
            transition: all 0.3s ease;
        }

        .light-mode .input-field {
            background-color: rgba(0, 0, 0, 0.05);
            border: 1px solid rgba(0, 0, 0, 0.1);
            color: var(--primary-dark);
        }

        .input-field:focus {
            outline: none;
            border-color: var(--accent-color);
            box-shadow: 0 0 0 2px rgba(59, 130, 246, 0.5);
        }

        .message-bubble {
            max-width: 80%;
            word-wrap: break-word;
            border-radius: 1rem;
            padding: 0.75rem 1rem;
            margin-bottom: 0.5rem;
            position: relative;
        }

        .remote-message {
            background-color: var(--secondary-dark);
            border-top-left-radius: 0;
        }

        .light-mode .remote-message {
            background-color: var(--secondary-light);
        }

        .local-message {
            background-color: var(--accent-color);
            border-top-right-radius: 0;
            color: white;
        }

        .security-badge {
            position: absolute;
            bottom: -20px;
            right: 10px;
            font-size: 0.7rem;
            color: var(--success-color);
        }

        .fade-in {
            animation: fadeIn 0.5s ease-in-out;
        }

        @keyframes fadeIn {
            from { opacity: 0; transform: translateY(10px); }
            to { opacity: 1; transform: translateY(0); }
        }

        .participant-card {
            display: flex;
            align-items: center;
            padding: 0.5rem;
            border-radius: 0.5rem;
            margin-bottom: 0.5rem;
        }

        .participant-avatar {
            width: 32px;
            height: 32px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin-right: 0.75rem;
            font-weight: bold;
            color: white;
        }

        .encryption-indicator {
            display: flex;
            align-items: center;
            color: var(--success-color);
            font-size: 0.8rem;
            margin-top: 0.5rem;
        }

        .login-container {
            max-width: 400px;
            margin: 0 auto;
            padding: 2rem;
        }

        .brand-logo {
            filter: drop-shadow(0 0 8px rgba(59, 130, 246, 0.5));
        }