* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        :root {
            --bg-primary: #ffffff;
            --bg-secondary: #f8f9fa;
            --bg-tertiary: #f1f3f4;
            --text-primary: #202124;
            --text-secondary: #5f6368;
            --text-tertiary: #80868b;
            --border-color: #dadce0;
            --accent-color: #1a73e8;
            --accent-hover: #1765cc;
            --success-color: #34a853;
            --warning-color: #fbbc04;
            --error-color: #ea4335;
            --shadow: 0 1px 2px 0 rgba(60,64,67,0.3), 0 1px 3px 1px rgba(60,64,67,0.15);
            --shadow-hover: 0 1px 3px 0 rgba(60,64,67,0.3), 0 4px 8px 3px rgba(60,64,67,0.15);
        }

        body.dark-mode {
            --bg-primary: #202124;
            --bg-secondary: #292a2d;
            --bg-tertiary: #35363a;
            --text-primary: #e8eaed;
            --text-secondary: #9aa0a6;
            --text-tertiary: #5f6368;
            --border-color: #5f6368;
        }

        body {
            font-family: 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
            background-color: var(--bg-secondary);
            color: var(--text-primary);
            line-height: 1.6;
            transition: background-color 0.3s, color 0.3s;
        }

        .header {
            background-color: var(--bg-primary);
            border-bottom: 1px solid var(--border-color);
          
            position: sticky;
            top: 0;
            z-index: 100;
            transition: background-color 0.3s;
        }

        .header-content {
            max-width: 1400px;
            margin: 0 auto;
            display: flex;
            justify-content: space-between;
            align-items: center;
            flex-wrap: wrap;
            gap: 16px;
        }

        .logo {
            font-size: 20px;
            font-weight: 500;
            color: var(--text-primary);
            display: flex;
            align-items: center;
            gap: 8px;
        }

        .header-actions {
            display: flex;
            gap: 12px;
            align-items: center;
        }

        .btn {
            padding: 10px 16px;
            border: none;
            border-radius: 8px;
            cursor: pointer;
            font-size: 14px;
            font-weight: 500;
            transition: all 0.2s;
            display: inline-flex;
            align-items: center;
            gap: 8px;
            background-color: var(--bg-tertiary);
            color: var(--text-primary);
        }

        .btn:hover {
            box-shadow: var(--shadow);
            transform: translateY(-1px);
        }

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

        .btn-primary:hover {
            background-color: var(--accent-hover);
        }

        .btn-secondary {
            background-color: var(--bg-secondary);
            border: 1px solid var(--border-color);
        }

        .btn-secondary:hover {
            background-color: var(--bg-tertiary);
            border-color: var(--accent-color);
        }

        .btn-icon {
            padding: 8px;
            border-radius: 50%;
            background-color: transparent;
        }

        .btn-icon:hover {
            background-color: var(--bg-tertiary);
        }

        .tabs {
            display: flex;
            gap: 4px;
            margin-top: 12px;
        }

        .tab {
            padding: 10px 20px;
            background-color: transparent;
            border: none;
            border-radius: 8px 8px 0 0;
            cursor: pointer;
            font-size: 14px;
            font-weight: 500;
            color: var(--text-secondary);
            transition: all 0.2s;
        }

        .tab.active {
            background-color: var(--bg-tertiary);
            color: var(--accent-color);
        }

        .tab:hover {
            background-color: var(--bg-tertiary);
        }

        .container {
            max-width: 1400px;
            margin: 24px auto;
            padding: 0 24px;
        }

        .main-grid {
            display: grid;
            grid-template-columns: 1fr 400px;
            gap: 24px;
        }

        @media (max-width: 1024px) {
            .main-grid {
                grid-template-columns: 1fr;
            }
        }

        .editor-section {
            display: flex;
            flex-direction: column;
            gap: 24px;
        }

        .card {
            background-color: var(--bg-primary);
            border: 1px solid var(--border-color);
            border-radius: 12px;
            padding: 28px;
            transition: all 0.3s;
            box-shadow: 0 2px 4px rgba(0,0,0,0.05);
        }

        .card:hover {
            box-shadow: var(--shadow-hover);
            border-color: var(--accent-color);
        }

        .card-title {
            font-size: 16px;
            font-weight: 500;
            margin-bottom: 16px;
            color: var(--text-primary);
            display: flex;
            align-items: center;
            gap: 8px;
        }

        .textarea-wrapper {
            position: relative;
        }

        .text-input {
            width: 100%;
            min-height: 400px;
            padding: 20px;
            border: 2px solid var(--border-color);
            border-radius: 12px;
            font-size: 15px;
            font-family: 'Segoe UI', system-ui, sans-serif;
            line-height: 1.6;
            resize: vertical;
            background-color: var(--bg-primary);
            color: var(--text-primary);
            transition: all 0.3s ease;
        }

        .text-input:focus {
            outline: none;
            border-color: var(--accent-color);
            box-shadow: 0 0 0 4px rgba(26, 115, 232, 0.12);
            transform: translateY(-1px);
        }

        .text-input::placeholder {
            color: var(--text-tertiary);
            font-style: italic;
        }

        .drag-overlay {
            position: absolute;
            inset: 0;
            background-color: rgba(26, 115, 232, 0.1);
            border: 2px dashed var(--accent-color);
            border-radius: 8px;
            display: none;
            align-items: center;
            justify-content: center;
            pointer-events: none;
        }

        .drag-overlay.active {
            display: flex;
        }

        .stats-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
            gap: 16px;
        }

        .stat-card {
            background-color: var(--bg-secondary);
            padding: 16px;
            border-radius: 8px;
            border: 1px solid var(--border-color);
            transition: all 0.2s;
        }

        .stat-card:hover {
            box-shadow: var(--shadow);
        }

        .stat-label {
            font-size: 12px;
            color: var(--text-secondary);
            display: flex;
            align-items: center;
            gap: 6px;
            margin-bottom: 8px;
        }

        .stat-value {
            font-size: 28px;
            font-weight: 600;
            color: var(--text-primary);
        }

        .sidebar {
            display: flex;
            flex-direction: column;
            gap: 24px;
        }

        .progress-bar {
            width: 100%;
            height: 8px;
            background-color: var(--bg-tertiary);
            border-radius: 4px;
            overflow: hidden;
        }

        .progress-fill {
            height: 100%;
            background-color: var(--success-color);
            transition: width 0.3s, background-color 0.3s;
            border-radius: 4px;
        }

        .progress-fill.warning {
            background-color: var(--warning-color);
        }

        .progress-fill.error {
            background-color: var(--error-color);
        }

        .keyword-list {
            display: flex;
            flex-direction: column;
            gap: 12px;
        }

        .keyword-item {
            display: flex;
            justify-content: space-between;
            align-items: center;
        }

        .keyword-bar {
            flex: 1;
            margin: 0 12px;
        }

        .readability-score {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 12px 0;
            border-bottom: 1px solid var(--border-color);
        }

        .readability-score:last-child {
            border-bottom: none;
        }

        .checkbox-wrapper {
            display: flex;
            align-items: center;
            gap: 8px;
            margin: 8px 0;
        }

        .checkbox-wrapper input[type="checkbox"] {
            width: 18px;
            height: 18px;
            cursor: pointer;
        }

        .range-wrapper {
            margin: 16px 0;
        }

        .range-wrapper label {
            display: block;
            margin-bottom: 8px;
            font-size: 14px;
            color: var(--text-secondary);
        }

        .range-wrapper input[type="range"] {
            width: 100%;
            cursor: pointer;
        }

        .select-wrapper {
            margin: 16px 0;
        }

        .select-wrapper select {
            width: 100%;
            padding: 10px;
            border: 1px solid var(--border-color);
            border-radius: 4px;
            background-color: var(--bg-primary);
            color: var(--text-primary);
            font-size: 14px;
            cursor: pointer;
        }

        .comparison-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 16px;
        }

        @media (max-width: 768px) {
            .comparison-grid {
                grid-template-columns: 1fr;
            }
        }

        .comparison-textarea {
            width: 100%;
            min-height: 200px;
            padding: 12px;
            border: 1px solid var(--border-color);
            border-radius: 8px;
            font-size: 14px;
            font-family: inherit;
            resize: vertical;
            background-color: var(--bg-primary);
            color: var(--text-primary);
        }

        .comparison-results {
            display: flex;
            flex-direction: column;
            gap: 12px;
            margin-top: 16px;
        }

        .comparison-row {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 12px;
            background-color: var(--bg-secondary);
            border-radius: 4px;
        }

        .history-list {
            display: flex;
            flex-direction: column;
            gap: 12px;
            max-height: 500px;
            overflow-y: auto;
        }

        .history-item {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 12px;
            background-color: var(--bg-secondary);
            border-radius: 4px;
            cursor: pointer;
            transition: all 0.2s;
        }

        .history-item:hover {
            background-color: var(--bg-tertiary);
        }

        .dropdown {
            position: relative;
        }

        .dropdown-menu {
            position: absolute;
            top: 100%;
            right: 0;
            margin-top: 8px;
            background-color: var(--bg-primary);
            border: 1px solid var(--border-color);
            border-radius: 8px;
            box-shadow: var(--shadow-hover);
            min-width: 200px;
            display: none;
            z-index: 1000;
        }

        .dropdown-menu.show {
            display: block;
        }

        .dropdown-item {
            padding: 12px 16px;
            cursor: pointer;
            display: flex;
            align-items: center;
            gap: 12px;
            font-size: 14px;
            color: var(--text-primary);
            transition: background-color 0.2s;
        }

        .dropdown-item:hover {
            background-color: var(--bg-tertiary);
        }

        .dropdown-item:first-child {
            border-radius: 8px 8px 0 0;
        }

        .dropdown-item:last-child {
            border-radius: 0 0 8px 8px;
        }

        .alert {
            padding: 12px;
            border-radius: 4px;
            display: flex;
            align-items: center;
            gap: 12px;
            margin-top: 12px;
        }

        .alert-success {
            background-color: rgba(52, 168, 83, 0.1);
            color: var(--success-color);
            border: 1px solid var(--success-color);
        }

        .alert-warning {
            background-color: rgba(251, 188, 4, 0.1);
            color: var(--warning-color);
            border: 1px solid var(--warning-color);
        }

        .alert-error {
            background-color: rgba(234, 67, 53, 0.1);
            color: var(--error-color);
            border: 1px solid var(--error-color);
        }

        .input-wrapper {
            margin: 16px 0;
        }

        .input-wrapper label {
            display: block;
            margin-bottom: 8px;
            font-size: 14px;
            font-weight: 500;
            color: var(--text-primary);
        }

        .input-wrapper input[type="text"] {
            width: 100%;
            padding: 10px;
            border: 1px solid var(--border-color);
            border-radius: 4px;
            background-color: var(--bg-primary);
            color: var(--text-primary);
            font-size: 14px;
        }

        .input-wrapper input[type="text"]:focus {
            outline: none;
            border-color: var(--accent-color);
            box-shadow: 0 0 0 3px rgba(26, 115, 232, 0.1);
        }

        .hidden {
            display: none !important;
        }

        .loading {
            display: flex;
            justify-content: center;
            align-items: center;
            padding: 20px;
            flex-wrap: wrap;
    gap: 10px;
        }

        .spinner {
            width: 40px;
            height: 40px;
            border: 4px solid var(--border-color);
            border-top-color: var(--accent-color);
            border-radius: 50%;
            animation: spin 1s linear infinite;
        }

        @keyframes spin {
            to { transform: rotate(360deg); }
        }

        .metric-grid {
            display: grid;
            grid-template-columns: repeat(2, 1fr);
            gap: 12px;
            margin-top: 16px;
        }

        .metric-item {
            padding: 12px;
            background-color: var(--bg-secondary);
            border-radius: 4px;
        }

        .metric-label {
            font-size: 12px;
            color: var(--text-secondary);
            margin-bottom: 4px;
        }

        .metric-value {
            font-size: 18px;
            font-weight: 600;
            color: var(--text-primary);
        }