:root {
            --primary-color: #4a6cf7;
            --primary-light: #6a88f7;
            --bg-color: #f8fafc;
            --card-bg: #ffffff;
            --text-color: #2d3748;
            --text-light: #718096;
            --border-color: #e2e8f0;
            --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
            --radius: 12px;
            --transition: all 0.3s ease;
        }
        .dark-mode {
            --primary-color: #5b7cfa;
            --primary-light: #7a97fa;
            --bg-color: #1a202c;
            --card-bg: #2d3748;
            --text-color: #f7fafc;
            --text-light: #cbd5e0;
            --border-color: #4a5568;
            --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -1px rgba(0, 0, 0, 0.2);
        }
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        body {
            background-color: var(--bg-color);
            color: var(--text-color);
            line-height: 1.6;
            transition: var(--transition);
            padding: 20px;
            min-height: 100vh;
        }
        .container {
            max-width: 800px;
            margin: 0 auto;
        }
        header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 30px;
            padding-bottom: 20px;
            border-bottom: 1px solid var(--border-color);
        }
        h1 {
            font-size: 2rem;
            font-weight: 700;
            color: var(--primary-color);
        }
        .theme-toggle {
            background: var(--card-bg);
            border: 1px solid var(--border-color);
            border-radius: 50%;
            width: 44px;
            height: 44px;
            display: flex;
            align-items: center;
            justify-content: center;
            cursor: pointer;
            transition: var(--transition);
            color: var(--text-color);
            box-shadow: var(--shadow);
        }
        .theme-toggle:hover {
            transform: translateY(-2px);
            box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
        }
        .chat-link {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            background: var(--primary-color);
            color: white;
            padding: 10px 16px;
            border-radius: var(--radius);
            text-decoration: none;
            font-weight: 500;
            transition: var(--transition);
            margin-top: 10px;
        }
        .chat-link:hover {
            background: var(--primary-light);
            transform: translateY(-2px);
        }
        .message-form {
            background: var(--card-bg);
            border-radius: var(--radius);
            padding: 24px;
            margin-bottom: 30px;
            box-shadow: var(--shadow);
        }
        .form-group {
            margin-bottom: 16px;
        }
        label {
            display: block;
            margin-bottom: 8px;
            font-weight: 500;
            color: var(--text-color);
        }
        input,
        textarea {
            width: 100%;
            padding: 12px 16px;
            border: 1px solid var(--border-color);
            border-radius: var(--radius);
            background: var(--bg-color);
            color: var(--text-color);
            font-size: 16px;
            transition: var(--transition);
        }
        input:focus,
        textarea:focus {
            outline: none;
            border-color: var(--primary-color);
            box-shadow: 0 0 0 3px rgba(74, 108, 247, 0.1);
        }
        .avatar-section {
            display: flex;
            gap: 16px;
            align-items: center;
            margin-bottom: 16px;
        }
        .avatar-preview {
            width: 50px;
            height: 50px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: bold;
            color: white;
            font-size: 1.2rem;
            overflow: hidden;
            background-size: cover;
            background-position: center;
        }
        .avatar-options {
            flex: 1;
        }
        .avatar-toggle {
            display: flex;
            gap: 10px;
            margin-bottom: 10px;
        }
        .toggle-btn {
            padding: 8px 16px;
            border: 1px solid var(--border-color);
            border-radius: var(--radius);
            background: var(--bg-color);
            color: var(--text-color);
            cursor: pointer;
            transition: var(--transition);
            font-size: 14px;
        }
        .toggle-btn.active {
            background: var(--primary-color);
            color: white;
            border-color: var(--primary-color);
        }
        .color-picker {
            display: flex;
            flex-wrap: wrap;
            gap: 8px;
            margin-top: 10px;
        }
        .color-option {
            width: 30px;
            height: 30px;
            border-radius: 50%;
            cursor: pointer;
            border: 2px solid transparent;
            transition: var(--transition);
        }
        .color-option.selected {
            border-color: var(--text-color);
            transform: scale(1.1);
        }
        .markdown-toggle {
            display: flex;
            align-items: center;
            gap: 8px;
            margin-bottom: 16px;
        }
        .markdown-toggle input {
            width: auto;
        }
        .submit-btn {
            background: var(--primary-color);
            color: white;
            border: none;
            padding: 12px 24px;
            border-radius: var(--radius);
            font-weight: 600;
            cursor: pointer;
            transition: var(--transition);
            width: 100%;
            font-size: 16px;
        }
        .submit-btn:hover {
            background: var(--primary-light);
            transform: translateY(-2px);
        }
        .search-box {
            margin-bottom: 20px;
            position: relative;
        }
        .search-box input {
            padding-left: 40px;
        }
        .search-icon {
            position: absolute;
            left: 12px;
            top: 50%;
            transform: translateY(-50%);
            color: var(--text-light);
        }
        .messages-container {
            margin-bottom: 30px;
        }
        .message-card {
            background: var(--card-bg);
            border-radius: var(--radius);
            padding: 20px;
            margin-bottom: 20px;
            box-shadow: var(--shadow);
            transition: var(--transition);
        }
        .message-card:hover {
            transform: translateY(-2px);
            box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
        }
        .message-header {
            display: flex;
            align-items: center;
            margin-bottom: 12px;
        }
        .message-avatar {
            width: 40px;
            height: 40px;
            border-radius: 50%;
            margin-right: 12px;
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: bold;
            color: white;
            font-size: 1rem;
            background-size: cover;
            background-position: center;
        }
        .message-info {
            flex: 1;
        }
        .message-author {
            font-weight: 600;
            color: var(--text-color);
        }
        .message-time {
            font-size: 0.85rem;
            color: var(--text-light);
        }
        .message-actions {
            display: flex;
            gap: 12px;
        }
        .action-btn {
            background: none;
            border: none;
            color: var(--text-light);
            cursor: pointer;
            transition: var(--transition);
            display: flex;
            align-items: center;
            gap: 4px;
            font-size: 0.9rem;
        }
        .action-btn:hover {
            color: var(--primary-color);
        }
        .message-content {
            margin-bottom: 16px;
            line-height: 1.6;
        }
        .message-content p {
            margin-bottom: 10px;
        }
        .reply-form {
            margin-top: 16px;
            padding-top: 16px;
            border-top: 1px solid var(--border-color);
        }
        .reply-form textarea {
            margin-bottom: 10px;
            min-height: 80px;
        }
        .replies {
            margin-top: 16px;
            padding-left: 20px;
            border-left: 2px solid var(--border-color);
        }
        .reply-card {
            background: var(--bg-color);
            border-radius: var(--radius);
            padding: 16px;
            margin-bottom: 12px;
        }
        .reply-header {
            display: flex;
            align-items: center;
            margin-bottom: 8px;
        }
        .reply-avatar {
            width: 30px;
            height: 30px;
            border-radius: 50%;
            margin-right: 10px;
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: bold;
            color: white;
            font-size: 0.8rem;
            background-size: cover;
            background-position: center;
        }
        .pagination {
            display: flex;
            justify-content: center;
            gap: 8px;
            margin-bottom: 30px;
        }
        .page-btn {
            padding: 8px 16px;
            border: 1px solid var(--border-color);
            border-radius: var(--radius);
            background: var(--card-bg);
            color: var(--text-color);
            cursor: pointer;
            transition: var(--transition);
        }
        .page-btn.active {
            background: var(--primary-color);
            color: white;
            border-color: var(--primary-color);
        }
        .page-btn:hover:not(.active) {
            background: var(--bg-color);
        }
        .admin-panel {
            background: var(--card-bg);
            border-radius: var(--radius);
            padding: 20px;
            margin-bottom: 30px;
            box-shadow: var(--shadow);
        }
        .admin-login {
            display: flex;
            gap: 10px;
            margin-bottom: 16px;
        }
        .admin-login input {
            flex: 1;
        }
        .admin-btn {
            background: var(--primary-color);
            color: white;
            border: none;
            padding: 10px 16px;
            border-radius: var(--radius);
            cursor: pointer;
            transition: var(--transition);
        }
        .admin-btn:hover {
            background: var(--primary-light);
        }
        .admin-actions {
            display: flex;
            gap: 10px;
        }
        .delete-btn {
            background: #e53e3e;
            color: white;
            border: none;
            padding: 6px 12px;
            border-radius: var(--radius);
            cursor: pointer;
            transition: var(--transition);
            font-size: 0.85rem;
        }
        .delete-btn:hover {
            background: #c53030;
        }
        .modal {
            display: none;
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(0, 0, 0, 0.5);
            align-items: center;
            justify-content: center;
            z-index: 1000;
        }
        .modal-content {
            background: var(--card-bg);
            border-radius: var(--radius);
            padding: 24px;
            max-width: 500px;
            width: 90%;
            box-shadow: var(--shadow);
        }
        .modal-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 16px;
        }
        .modal-title {
            font-size: 1.25rem;
            font-weight: 600;
        }
        .close-btn {
            background: none;
            border: none;
            font-size: 1.5rem;
            color: var(--text-light);
            cursor: pointer;
        }
        @media (max-width: 768px) {
            body {
                padding: 16px;
            }
            h1 {
                font-size: 1.5rem;
            }
            .message-form,
            .message-card {
                padding: 16px;
            }
            .avatar-section {
                flex-direction: column;
                align-items: flex-start;
            }
            .replies {
                padding-left: 10px;
            }
        }