:root {
            --primary-blue: #1877f2;
            --background-light: #f0f2f5;
            --text-dark: #1c1e21;
        }

        body {
            font-family: 'Inter', sans-serif;
            background-color: var(--background-light);
            color: var(--text-dark);
            height: 100vh;
            overflow: hidden;
            display: flex; /* Added for centering loading spinner */
            justify-content: center; /* Added for centering loading spinner */
            align-items: center; /* Added for centering loading spinner */
        }

        .chat-container {
            display: grid;
            grid-template-columns: 350px 1fr;
            height: 100vh;
            width: 100%; /* Ensure it takes full width when visible */
        }

        .conversations-list {
            border-right: 1px solid #e5e7eb;
            overflow-y: auto;
            background-color: white;
        }

        .chat-area {
            display: flex;
            flex-direction: column;
            height: 100vh;
        }

        .messages-container {
            flex: 1;
            overflow-y: auto;
            padding: 1rem;
            background-color: #f9fafb;
        }

        .message-input-container {
            padding: 1rem;
            border-top: 1px solid #e5e7eb;
            background-color: white;
        }

        .conversation-item {
            padding: 1rem;
            border-bottom: 1px solid #e5e7eb;
            cursor: pointer;
            transition: background-color 0.2s;
        }

        .conversation-item:hover {
            background-color: #f3f4f6;
        }

        .conversation-item.active {
            background-color: #e5e7eb;
        }

        .followed-user-item {
            padding: 1rem;
            border-bottom: 1px solid #e5e7eb;
            cursor: pointer;
            transition: background-color 0.2s;
        }

        .followed-user-item:hover {
            background-color: #f3f4f6;
        }

        .message {
            max-width: 70%;
            margin-bottom: 1rem;
            padding: 0.75rem 1rem;
            border-radius: 1rem;
            word-wrap: break-word;
        }

        .message.sent {
            background-color: var(--primary-blue);
            color: white;
            margin-left: auto;
            border-bottom-right-radius: 0.25rem;
        }

        .message.received {
            background-color: white;
            color: var(--text-dark);
            margin-right: auto;
            border-bottom-left-radius: 0.25rem;
            box-shadow: 0 1px 2px rgba(0,0,0,0.1);
        }

        .message-time {
            font-size: 0.75rem;
            color: #6b7280;
            margin-top: 0.25rem;
            text-align: right;
        }

        .unread-badge {
            background-color: var(--primary-blue);
            color: white;
            border-radius: 9999px;
            padding: 0.25rem 0.5rem;
            font-size: 0.75rem;
            margin-left: auto;
        }

        .chat-header {
            padding: 1rem;
            border-bottom: 1px solid #e5e7eb;
            background-color: white;
            display: flex;
            align-items: center;
        }

        .empty-state {
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            height: 100%;
            text-align: center;
            padding: 2rem;
            color: #6b7280;
        }

        .skeleton-message {
            height: 60px;
            background-color: #e5e7eb;
            border-radius: 0.5rem;
            margin-bottom: 1rem;
            position: relative;
            overflow: hidden;
        }

        .skeleton-message::after {
            content: '';
            position: absolute;
            top: 0;
            left: -100%;
            width: 100%;
            height: 100%;
            background: linear-gradient(90deg, transparent, rgba(255,255,255,0.4), transparent);
            animation: shimmer 1.5s infinite;
        }

        @keyframes shimmer {
            100% { left: 100%; }
        }

        .search-bar {
            padding: 0.75rem 1rem;
            border-bottom: 1px solid #e5e7eb;
            background-color: white;
        }

        .search-input {
            width: 100%;
            padding: 0.5rem 1rem;
            border-radius: 1rem;
            border: 1px solid #e5e7eb;
            outline: none;
            background-color: #f3f4f6;
        }

        .search-input:focus {
            background-color: white;
            border-color: var(--primary-blue);
        }

        .tab-button {
            padding: 0.75rem 1rem;
            border-bottom: 2px solid transparent;
            font-weight: 500;
            color: #6b7280;
            cursor: pointer;
        }

        .tab-button.active {
            color: var(--primary-blue);
            border-bottom-color: var(--primary-blue);
        }

        .tabs-container {
            display: flex;
            border-bottom: 1px solid #e5e7eb;
            background-color: white;
        }

        .auth-modal {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background-color: rgba(0, 0, 0, 0.5);
            display: flex;
            justify-content: center;
            align-items: center;
            z-index: 1000;
        }

        .auth-form {
            background-color: white;
            padding: 2rem;
            border-radius: 0.75rem;
            box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
            width: 100%;
            max-width: 400px;
            text-align: center;
        }

        .auth-form input {
            width: 100%;
            padding: 0.75rem;
            margin-bottom: 1rem;
            border: 1px solid #d1d5db;
            border-radius: 0.5rem;
            font-size: 1rem;
        }

        .auth-form button {
            width: 100%;
            padding: 0.75rem;
            border-radius: 0.5rem;
            font-weight: 600;
            cursor: pointer;
            transition: background-color 0.2s;
        }

        .auth-form .error-message {
            color: #ef4444;
            margin-top: -0.5rem;
            margin-bottom: 1rem;
            font-size: 0.875rem;
        }

        /* Removed Loading Spinner Styles */
        /*
        .loading-spinner {
            border: 4px solid rgba(0, 0, 0, 0.1);
            border-left-color: var(--primary-blue);
            border-radius: 50%;
            width: 50px;
            height: 50px;
            animation: spin 1s linear infinite;
        }

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

        @media (max-width: 768px) {
            .chat-container {
                grid-template-columns: 1fr;
            }
            .conversations-list {
                display: none;
            }
            .conversations-list.active {
                display: block;
            }
            .chat-area {
                display: none;
            }
            .chat-area.active {
                display: flex;
            }
        }