:root {
            --bg: #030712;
            --card-bg: #0b1329;
            --text: #f9fafb;
            --muted: #9ca3af;
            --accent: #2563eb;
            --border: #1f2937;
        }

        * {
            box-sizing: border-box;
        }

        body {
            font-family: system-ui, -apple-system, sans-serif;
            background: var(--bg);
            color: var(--text);
            margin: 0;
            padding: 0;
            line-height: 1.6;
        }

        .container {
            max-width: 1000px;
            margin: 0 auto;
            padding: 0 20px;
        }

        header {
            padding: 90px 0 40px 0;
            text-align: center;
        }

        header h1 {
            font-size: 56px;
            font-weight: 800;
            margin: 0;
            letter-spacing: -0.04em;
        }

        .tagline {
            font-size: 20px;
            color: var(--muted);
            margin: 15px 0 30px 0;
        }

        .btn-group {
            display: flex;
            justify-content: center;
            gap: 10px;
            margin-bottom: 30px;
        }

        .btn-tab {
            background: #111827;
            color: var(--text);
            border: 1px solid var(--border);
            padding: 8px 16px;
            border-radius: 6px;
            cursor: pointer;
            font-weight: 500;
        }

        .btn-tab:hover {
            border-color: var(--accent);
        }

        .workspace {
            display: flex;
            gap: 20px;
            min-height: 320px;
            margin-bottom: 40px;
        }

        @media (max-width: 768px) {
            .workspace {
                flex-direction: column;
            }
        }

        .editor-box {
            flex: 1;
            background: #010409;
            border: 1px solid var(--border);
            border-radius: 10px;
            display: flex;
            overflow: hidden;
        }

        .lines {
            padding: 15px 10px;
            background: #0d1117;
            color: #484f58;
            font-family: monospace;
            font-size: 16px;
            text-align: right;
            line-height: 1.5;
            user-select: none;
        }

        textarea {
            flex: 1;
            background: transparent;
            color: #7ee787;
            border: none;
            resize: none;
            font-family: monospace;
            font-size: 16px;
            padding: 15px;
            outline: none;
            line-height: 1.5;
        }

        .panel-right {
            width: 380px;
            display: flex;
            flex-direction: column;
            gap: 15px;
        }

        @media (max-width: 768px) {
            .panel-right {
                width: 100%;
            }
        }

        .btn-run {
            background: #238636;
            color: white;
            border: none;
            padding: 14px;
            font-size: 16px;
            font-weight: bold;
            border-radius: 6px;
            cursor: pointer;
        }

        .btn-run:hover {
            background: #2ea043;
        }

        .meta-box {
            background: #161b22;
            border: 1px solid var(--border);
            padding: 12px;
            border-radius: 6px;
            font-family: monospace;
            font-size: 14px;
            color: #58a6ff;
        }

        pre {
            flex: 1;
            background: #010409;
            border: 1px solid var(--border);
            padding: 15px;
            font-size: 15px;
            border-radius: 8px;
            color: #ffa657;
            font-family: monospace;
            margin: 0;
            white-space: pre-wrap;
        }

        footer {
            text-align: center;
            padding: 30px 0;
            color: var(--muted);
            font-size: 14px;
            border-top: 1px solid var(--border);
            margin-top: 40px;
        }