里，但 document_idle 会重建 body 把界面冲掉。 * · .csv / .tsv 通常没有查看器：要么直接下载，要么是一张空白页，
 里什么都没有。
 *     只读  就会表现为「JSON 能开，CSV 完全不解析」。
 *   对策：
 *     1. 有  就先抓快照（JSON 这条同步路径不能等，查看器马上会把页面换掉）；
 *     2.  是空的就按 file:// 地址把字节读回来（UTF-8 失败再试 gb18030）；
 *     3. 挂界面前摘掉 .json-formatter-container，并用 MutationObserver 在根节点被冲掉后挂回去。
 *
 * 数据特性
 *   · CSV 按 RFC 4180 解析：支持引号包裹、"" 转义、字段内逗号/换行、CRLF、BOM。
 *   · 分隔符自动嗅探（, ; Tab |），按首行一致性打分选最优。
 *   · 每列自动推断类型（数字/布尔/文本），排序和统计都按推断后的类型走。
 *     超出 JS 安全整数的纯数字（如 17 位 SteamID）保持文本，避免另存为 JSON 时丢精度。
 *   · JSON 支持对象数组、数组的数组、纯原始值数组；不是数组时退化成可折叠树视图。
 *   · 大文件只渲染当前页，DOM 节点数与总行数无关。
 */

(function () {
    'use strict';

    /* ============================================================
     * 0. 常量与状态
     * ============================================================ */

    const VERSION = '1.2.2';

    const ROOT_ID = 'dr-reader-root';
    const EXT_DATA = ['json', 'csv', 'tsv'];
    const PAGE_SIZES = [50, 100, 200, 500, 1000];
    const DEFAULT_PAGE = 100;
    const MAX_AUTO_PARSE = 64 * 1024 * 1024;   // 超过 64MB 就不再自动解析，避免把浏览器拖死
    const PREVIEW_DEBOUNCE = 300;

    const state = {
        fileName: 'data',
        format: 'json',            // json | csv | tsv
        original: '',              // 载入时的原文，用于「还原」和未保存判断
        text: '',                  // 当前原文（= textarea.value）
        model: null,               // 解析结果
        error: '',                 // 解析错误信息
        query: '',
        sortKey: null,
        sortDir: 0,                // 1 升序 / -1 降序 / 0 不排序
        page: 1,
        pageSize: DEFAULT_PAGE,
        hidden: {},                // { 列名: true } 隐藏的列
        showStats: false,
        stats: null,
        debounceTimer: 0
    };

    const refs = {};

    /**
     * 浏览器自带的 JSON 查看器（"美观输出"那个）会在 document_idle 阶段
     * 重建整个 body，把油猴脚本注入的界面直接冲掉 —— 表现就是「插件不生效」。
     * 所以正文必须一次性抓到自己手里，之后只认这份快照。
     */
    let capturedSource = null;

    function captureSource(force) {
        if (!force && capturedSource !== null) return capturedSource;
        let text = '';
        try {
            // 只认 。刻意不把任意页面的 body.textContent 当数据 ——
            // 那会把网页自己的脚本文本喂进解析器。
            const pre = document.querySelector('body > pre') || document.querySelector('pre');
            if (pre) text = pre.textContent || '';
            // 本地文件页有时没有 ，原文直接挂在 body 的文本节点上。
            // 已经有子元素时不再收：那是脚本自己的界面，或者是别的网页。
            if (!text && location.protocol === 'file:' && document.body && !document.body.firstElementChild) {
                text = document.body.textContent || '';
            }
        } catch (e) {
            text = '';
        }
        // 空读不写入缓存。否则 DOMContentLoaded 时  还没出来，
        // 这次空字符串会把后面 load / 重新读取永远挡住。
        if (text) capturedSource = text;
        return text || capturedSource || '';
    }

    /** 摘掉浏览器自带查看器的挂载点，避免它继续往页面上盖东西 */
    function killNativeViewer() {
        try {
            document.querySelectorAll('.json-formatter-container').forEach(function (el) { el.remove(); });
        } catch (e) { /* 忽略 */ }
    }

    /* ============================================================
     * 1. 小工具
     * ============================================================ */

    function escapeHtml(s) {
        return String(s == null ? '' : s)
            .replace(/&/g, '&')
            .replace(//g, '>')
            .replace(/"/g, '"')
            .replace(/'/g, ''');
    }

    function extOf(name) {
        const i = String(name || '').lastIndexOf('.');
        return i < 0 ? '' : String(name).slice(i + 1).toLowerCase();
    }

    function baseName(name) {
        return String(name || 'data').replace(/\.[^.]+$/, '') || 'data';
    }

    function fmtSize(n) {
        if (n == null) return '';
        const units = ['B', 'KB', 'MB', 'GB'];
        let i = 0, v = Number(n);
        while (v >= 1024 && i < units.length - 1) { v /= 1024; i++; }
        return (i === 0 ? v : v.toFixed(v < 10 ? 2 : 1)) + ' ' + units[i];
    }

    function downloadBlob(blob, filename) {
        const url = URL.createObjectURL(blob);
        const a = document.createElement('a');
        a.href = url;
        a.download = filename;
        a.style.display = 'none';
        document.body.appendChild(a);
        a.click();
        setTimeout(function () {
            try { a.remove(); } catch (e) { /* 忽略 */ }
            URL.revokeObjectURL(url);
        }, 4000);
    }

    /** UTF-8 严格解码，失败退 gb18030（中文 Windows 导出的 CSV 常见） */
    function decodeText(u8) {
        try {
            return new TextDecoder('utf-8', { fatal: true }).decode(u8);
        } catch (e) {
            try { return new TextDecoder('gb18030').decode(u8); } catch (e2) { return new TextDecoder('utf-8').decode(u8); }
        }
    }

    function stripBom(s) {
        return s.charCodeAt(0) === 0xFEFF ? s.slice(1) : s;
    }

    /* ============================================================
     * 2. 解析：CSV / JSON → 统一表格模型
     * ============================================================ */

    /**
     * RFC 4180 分隔符解析器。
     * 关键点：引号内的分隔符和换行都当普通字符；"" 是转义后的一个引号；
     * 未加引号字段里出现的引号按字面量处理。
     */
    function parseDelimited(text, delim) {
        const rows = [];
        let row = [], field = '', i = 0, inQuotes = false, touched = false;
        const n = text.length;
        while (i < n) {
            const ch = text[i];
            if (inQuotes) {
                if (ch === '"') {
                    if (text[i + 1] === '"') { field += '"'; i += 2; continue; }
                    inQuotes = false; i++; continue;
                }
                field += ch; i++; continue;
            }
            if (ch === '"' && field === '') { inQuotes = true; touched = true; i++; continue; }
            if (ch === delim) { row.push(field); field = ''; touched = true; i++; continue; }
            if (ch === '\r') { i++; continue; }
            if (ch === '\n') { row.push(field); rows.push(row); row = []; field = ''; touched = false; i++; continue; }
            field += ch; i++;
        }
        if (field !== '' || touched || row.length) { row.push(field); rows.push(row); }
        return rows;
    }

    /** 嗅探分隔符：取候选里「首行列数最多且后续行最齐」的那个 */
    function sniffDelim(text) {
        const candidates = [',', '\t', ';', '|'];
        let best = ',', bestScore = -1;
        for (let k = 0; k < candidates.length; k++) {
            const sample = parseDelimited(text.slice(0, 200 * 1024), candidates[k]).slice(0, 60);
            if (sample.length < 2) continue;
            const cols = sample[0].length;
            if (cols < 2) continue;
            let same = 0;
            for (let i = 1; i < sample.length; i++) if (sample[i].length === cols) same++;
            const score = same * 1000 + cols;
            if (score > bestScore) { bestScore = score; best = candidates[k]; }
        }
        return best;
    }

    const NUM_RE = /^-?(?:\d+\.?\d*|\.\d+)(?:[eE][+-]?\d+)?$/;
    const BOOL_RE = /^(?:true|false|yes|no|是|否|y|n)$/i;

    /**
     * 文本能不能当成 JS 数字。
     * 纯整数还必须是安全整数：SteamID 这种 17 位数字转 Number 会丢末尾精度，
     * 排序和「另存为 JSON」都会把好友 ID 改掉。
     */
    function isPreciseNumber(s) {
        if (!NUM_RE.test(s)) return false;
        if (/^-?\d+$/.test(s)) return Number.isSafeInteger(Number(s));
        const n = Number(s);
        return isFinite(n);
    }

    /** 按整列取值推断类型：全数字 → number，全布尔 → boolean，否则 string */
    function inferType(values) {
        let num = 0, bool = 0, txt = 0;
        for (let i = 0; i < values.length; i++) {
            const v = values[i];
            if (v === null || v === undefined || v === '') continue;
            if (typeof v === 'number') { num++; continue; }
            if (typeof v === 'boolean') { bool++; continue; }
            const s = String(v).trim();
            if (!s) continue;
            if (isPreciseNumber(s)) num++;
            else if (BOOL_RE.test(s)) bool++;
            else txt++;
        }
        if (num && !txt && !bool) return 'number';
        if (bool && !txt && !num) return 'boolean';
        return 'string';
    }

    /** 按列类型把单元格转成可排序/可统计的值；空值返回 undefined */
    function castVal(v, type) {
        if (v === null || v === undefined || v === '') return undefined;
        if (type === 'number') {
            if (typeof v === 'number') return isFinite(v) ? v : undefined;
            const s = String(v).trim();
            if (!isPreciseNumber(s)) return undefined;
            return Number(s);
        }
        if (type === 'boolean') {
            const s = String(v).trim();
            if (!s) return undefined;
            return /^(?:true|yes|y|是|1)$/i.test(s);
        }
        if (typeof v === 'object') return JSON.stringify(v);
        return String(v);
    }

    /** 单元格显示文本：嵌套结构压缩成摘要，完整内容放 title 里 */
    function cellText(v) {
        if (v === null) return 'null';
        if (v === undefined) return '';
        if (Array.isArray(v)) {
            if (!v.length) return '[]';
            const head = v.slice(0, 3).map(function (x) {
                return typeof x === 'object' && x !== null ? JSON.stringify(x) : String(x);
            }).join(', ');
            return '[' + v.length + '] ' + head + (v.length > 3 ? ' …' : '');
        }
        if (typeof v === 'object') {
            const keys = Object.keys(v);
            if (!keys.length) return '{}';
            return '{' + keys.length + '} ' + keys.slice(0, 3).join(', ') + (keys.length > 3 ? ' …' : '');
        }
        return String(v);
    }

    function cellTitle(v) {
        if (v !== null && v !== undefined && typeof v === 'object') {
            try { return JSON.stringify(v); } catch (e) { return ''; }
        }
        return '';
    }

    /** JSON 值 → 表格模型；非数组返回 kind:'tree' */
    function modelFromJson(value) {
        if (!Array.isArray(value)) {
            return { kind: 'tree', jsonValue: value, headers: [], rows: [] };
        }

        // 空数组：给出明确提示而不是空白表格
        if (!value.length) {
            return { kind: 'json', jsonValue: value, headers: [], rows: [], types: {} };
        }

        // 数组的数组 / 原始值数组 → 统一转成「每列一个 header」
        const allObjects = value.every(function (r) { return r !== null && typeof r === 'object' && !Array.isArray(r); });
        const width = value.reduce(function (m, r) {
            return Math.max(m, Array.isArray(r) ? r.length : 1);
        }, 0);

        let headers, rows, types;

        if (allObjects) {
            // 列顺序 = 首次出现顺序（不会因为后面某行多了个 key 就乱序）
            headers = [];
            const seen = {};
            for (let i = 0; i < value.length && headers.length < 500; i++) {
                const r = value[i];
                for (const k of Object.keys(r)) {
                    if (!Object.prototype.hasOwnProperty.call(seen, k)) { seen[k] = 1; headers.push(k); }
                }
            }
            rows = value.map(function (r) {
                return headers.map(function (h) { return r[h]; });
            });
        } else if (value.every(function (r) { return Array.isArray(r); })) {
            headers = [];
            for (let i = 0; i < width; i++) headers.push('列 ' + (i + 1));
            rows = value.map(function (r) {
                const out = new Array(width);
                for (let i = 0; i < width; i++) out[i] = r[i];
                return out;
            });
        } else {
            headers = ['值'];
            rows = value.map(function (r) { return [r]; });
        }

        types = {};
        for (let c = 0; c < headers.length; c++) {
            const col = new Array(rows.length);
            for (let r = 0; r < rows.length; r++) col[r] = rows[r][c];
            types[headers[c]] = inferType(col);
        }

        return { kind: 'json', jsonValue: value, headers: headers, rows: rows, types: types };
    }

    /** 文本 → 解析模型；格式靠扩展名 + 内容嗅探 */
    function parseData(text, fileName) {
        const raw = stripBom(String(text == null ? '' : text));
        const ext = extOf(fileName) || state.format;
        const looksJson = /^\s*[[{]/.test(raw);

        let format;
        if (ext === 'json') format = 'json';
        else if (ext === 'csv' || ext === 'tsv') format = 'csv';
        else format = looksJson ? 'json' : 'csv';
        state.format = ext === 'tsv' ? 'tsv' : (format === 'json' ? 'json' : 'csv');

        if (format === 'json') {
            let value;
            try {
                value = JSON.parse(raw);
            } catch (e) {
                throw new Error('JSON 解析失败：' + (e && e.message ? e.message : e));
            }
            const m = modelFromJson(value);
            m.format = 'json';
            if (ext === 'tsv') m.delim = '\t';
            return m;
        }

        const delim = ext === 'tsv' ? '\t' : sniffDelim(raw);
        const table = parseDelimited(raw, delim).filter(function (r) {
            return r.length > 1 || (r.length === 1 && r[0] !== '');
        });
        if (!table.length) throw new Error('没有解析到任何数据行');

        const headers = table[0].map(function (h, i) { return String(h).trim() || '列 ' + (i + 1); });
        const rows = table.slice(1).map(function (r) {
            const out = new Array(headers.length);
            for (let i = 0; i < headers.length; i++) out[i] = i < r.length ? r[i] : '';
            return out;
        });

        const types = {};
        for (let c = 0; c < headers.length; c++) {
            const col = new Array(rows.length);
            for (let r = 0; r < rows.length; r++) col[r] = rows[r][c];
            types[headers[c]] = inferType(col);
        }

        return {
            kind: 'csv',
            format: state.format,
            delim: delim,
            headers: headers,
            rows: rows,
            types: types,
            jsonValue: null
        };
    }

    /* ---------------- 序列化 ---------------- */

    function csvEscape(v) {
        let s;
        if (v === null || v === undefined) s = '';
        else if (typeof v === 'object') { try { s = JSON.stringify(v); } catch (e) { s = String(v); } }
        else s = String(v);
        return /[",\r\n]/.test(s) ? '"' + s.replace(/"/g, '""') + '"' : s;
    }

    function toCsv(model, delim) {
        const d = delim || (model && model.delim) || ',';
        const lines = [];
        lines.push((model.headers || []).map(csvEscape).join(d));
        (model.rows || []).forEach(function (r) {
            lines.push(r.map(csvEscape).join(d));
        });
        // 带 BOM，Excel / WPS 双击才不会乱码（和样例文件保持一致）
        return '\ufeff' + lines.join('\r\n') + '\r\n';
    }

    /** CSV 表格模型 → JSON 值（按列类型回填数字/布尔） */
    function tableToJson(model) {
        const headers = model.headers || [];
        return (model.rows || []).map(function (r) {
            const o = {};
            headers.forEach(function (h, i) {
                const type = (model.types && model.types[h]) || 'string';
                o[h] = castVal(r[i], type);
            });
            return o;
        });
    }

    /* ============================================================
     * 3. 样式
     * ============================================================ */

    const CSS = [
        'html,body{height:100%;}',
        'body{margin:0;padding:0;overflow:hidden;background:#1e1f29;color:#f8f8f2;',
        'font:13px/1.55 -apple-system,BlinkMacSystemFont,"Segoe UI","Microsoft YaHei",Helvetica,Arial,sans-serif;}',
        '.dr-root{display:flex;flex-direction:column;height:100vh;width:100vw;}',

        /* 顶部工具条 */
        '.dr-topbar{display:flex;align-items:center;gap:8px;flex-wrap:wrap;padding:6px 12px;flex:0 0 auto;',
        'background:#282a36;border-bottom:1px solid #44475a;}',
        '.dr-badge{display:inline-flex;align-items:center;justify-content:center;height:21px;padding:0 7px;border-radius:5px;',
        'font-size:10.5px;font-weight:700;letter-spacing:.5px;background:rgba(80,250,123,.14);border:1px solid rgba(80,250,123,.45);color:#50fa7b;}',
        '.dr-badge-csv{background:rgba(255,184,108,.14);border-color:rgba(255,184,108,.45);color:#ffb86c;}',
        '.dr-name{font-weight:600;font-size:13px;max-width:26vw;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;}',
        '.dr-meta{color:#6272a4;font-size:12px;white-space:nowrap;}',
        '.dr-dirty{color:#f1fa8c;font-size:12px;white-space:nowrap;}',
        '.dr-grow{flex:1 1 auto;}',
        '.dr-btn{appearance:none;border:1px solid #44475a;background:#313244;color:#f8f8f2;border-radius:6px;',
        'padding:4px 10px;font-size:12px;line-height:1.5;cursor:pointer;white-space:nowrap;transition:.14s;}',
        '.dr-btn:hover{border-color:#50fa7b;color:#50fa7b;}',
        '.dr-btn:active{transform:translateY(1px);}',
        '.dr-btn.primary{background:rgba(80,250,123,.16);border-color:rgba(80,250,123,.55);color:#50fa7b;font-weight:600;}',
        '.dr-btn.on{background:rgba(80,250,123,.24);border-color:#50fa7b;color:#50fa7b;}',
        '.dr-sel{appearance:none;background:#313244;color:#f8f8f2;border:1px solid #44475a;border-radius:6px;',
        'padding:4px 6px;font-size:12px;cursor:pointer;}',
        '.dr-search{background:#313244;border:1px solid #44475a;border-radius:6px;color:#f8f8f2;',
        'padding:4px 9px;font-size:12px;width:190px;outline:none;}',
        '.dr-search:focus{border-color:#50fa7b;}',
        '.dr-search::placeholder{color:#6272a4;}',

        /* 列显隐面板 */
        '.dr-colpanel{position:absolute;z-index:30;top:34px;right:12px;min-width:190px;max-height:60vh;overflow:auto;',
        'padding:7px 9px;border-radius:9px;background:#313244;border:1px solid #44475a;box-shadow:0 14px 40px rgba(0,0,0,.55);}',
        '.dr-colpanel h4{margin:0 0 6px;font-size:11px;color:#6272a4;font-weight:600;letter-spacing:.4px;}',
        '.dr-colpanel label{display:flex;align-items:center;gap:6px;font-size:12px;padding:3px 2px;cursor:pointer;border-radius:4px;}',
        '.dr-colpanel label:hover{background:#44475a;}',
        '.dr-colpanel input{accent-color:#50fa7b;}',
        '.dr-colpanel .dr-tp{color:#6272a4;font-size:10.5px;margin-left:auto;padding-left:10px;}',

        /* 统计面板 */
        '.dr-statspanel{flex:0 0 auto;max-height:30vh;overflow:auto;background:#21222c;border-bottom:1px solid #44475a;padding:8px 12px;}',
        '.dr-statspanel table{border-collapse:collapse;width:100%;font-size:12px;}',
        '.dr-statspanel th,.dr-statspanel td{border:1px solid #44475a;padding:3px 8px;text-align:left;white-space:nowrap;}',
        '.dr-statspanel th{background:#313244;color:#bd93f9;font-weight:600;}',
        '.dr-statspanel td{color:#cfd3e0;}',

        /* 分屏 */
        '.dr-split{flex:1 1 auto;display:flex;min-height:0;}',
        '.dr-pane{overflow:auto;box-sizing:border-box;height:100%;}',
        '.dr-pane-left{flex:1 1 0;min-width:0;background:#21222c;}',
        '.dr-pane-right{flex:1 1 0;min-width:0;background:#282a36;border-left:0;position:relative;}',
        '.dr-editor{width:100%;height:100%;background:transparent;color:#f8f8f2;border:none;resize:none;outline:none;padding:12px 14px;',
        'box-sizing:border-box;white-space:pre;overflow-wrap:normal;tab-size:2;',
        'font:12.5px/1.6 "SFMono-Regular",Consolas,"Liberation Mono",Menlo,monospace;}',
        '.dr-splitter{flex:0 0 6px;background:#44475a;cursor:col-resize;position:relative;z-index:5;transition:background .15s;}',
        '.dr-splitter:hover,.dr-splitter.dragging{background:#50fa7b;}',
        '.dr-splitter::after{content:"⋮";position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);color:#888;font-size:16px;line-height:1;}',

        /* 表格 */
        '.dr-tablewrap{padding:0 0 40px;}',
        '.dr-table{border-collapse:separate;border-spacing:0;font-size:12.5px;width:max-content;min-width:100%;}',
        '.dr-table th,.dr-table td{border-right:1px solid #44475a;border-bottom:1px solid #44475a;padding:5px 10px;',
        'white-space:nowrap;max-width:420px;overflow:hidden;text-overflow:ellipsis;vertical-align:top;}',
        '.dr-table thead th{position:sticky;top:0;z-index:2;background:#313244;color:#bd93f9;cursor:pointer;user-select:none;',
        'border-bottom:1px solid #6272a4;font-weight:600;}',
        '.dr-table thead th:hover{color:#50fa7b;}',
        '.dr-table thead th .dr-arrow{color:#50fa7b;font-size:10px;margin-left:4px;}',
        '.dr-table thead th .dr-tp{color:#6272a4;font-size:10px;margin-left:5px;font-weight:400;}',
        '.dr-table tbody tr:nth-child(even){background:rgba(255,255,255,.022);}',
        '.dr-table tbody tr:hover{background:rgba(80,250,123,.07);}',
        '.dr-table td.dr-num{text-align:right;font-family:"SFMono-Regular",Consolas,Menlo,monospace;color:#bd93f9;}',
        '.dr-table td.dr-bool{text-align:center;color:#ffb86c;}',
        '.dr-table td.dr-null{color:#6272a4;font-style:italic;}',
        '.dr-table td.dr-deep{color:#8be9fd;}',
        '.dr-table td.dr-rownum{color:#6272a4;background:rgba(255,255,255,.03);text-align:right;position:sticky;left:0;z-index:1;}',

        /* 分页条 */
        '.dr-foot{flex:0 0 auto;display:flex;align-items:center;gap:9px;flex-wrap:wrap;padding:5px 12px;',
        'background:#282a36;border-top:1px solid #44475a;color:#6272a4;font-size:12px;}',
        '.dr-foot b{color:#f8f8f2;font-weight:600;}',
        '.dr-foot .dr-btn{padding:2px 8px;font-size:11.5px;}',

        /* 空态 / 错误 */
        '.dr-empty{display:flex;flex-direction:column;align-items:center;justify-content:center;height:100%;gap:9px;',
        'color:#6272a4;text-align:center;padding:40px;}',
        '.dr-empty .dr-big{font-size:40px;line-height:1;}',
        '.dr-err{margin:14px;padding:12px 14px;border-radius:9px;background:rgba(255,85,85,.1);',
        'border:1px solid rgba(255,85,85,.45);color:#ffb3b3;font-size:12.5px;}',
        '.dr-err b{display:block;margin-bottom:4px;color:#ff6b6b;font-size:13px;}',
        '.dr-err code{background:rgba(0,0,0,.3);border-radius:4px;padding:1px 5px;color:#ffb3b3;}',

        /* 树视图 */
        '.dr-treewrap{padding:12px 14px;font-family:"SFMono-Regular",Consolas,Menlo,monospace;font-size:12.5px;line-height:1.6;}',
        '.dr-tree details{margin-left:14px;border-left:1px dotted #44475a;padding-left:10px;}',
        '.dr-tree summary{cursor:pointer;list-style:none;outline:none;}',
        '.dr-tree summary::-webkit-details-marker{display:none;}',
        '.dr-tree summary::before{content:"▸";display:inline-block;width:12px;color:#6272a4;transition:transform .12s;}',
        '.dr-tree details[open]>summary::before{transform:rotate(90deg);}',
        '.dr-tree .dr-k{color:#bd93f9;}',
        '.dr-tree .dr-s{color:#50fa7b;}',
        '.dr-tree .dr-n{color:#ffb86c;}',
        '.dr-tree .dr-b{color:#ff79c6;}',
        '.dr-tree .dr-null{color:#6272a4;font-style:italic;}',
        '.dr-tree .dr-cnt{color:#6272a4;font-size:11px;margin-left:6px;}',

        /* 拖放遮罩 */
        '#dr-drop-overlay{position:fixed;top:0;left:0;right:0;bottom:0;z-index:2147483646;display:flex;align-items:center;',
        'justify-content:center;background:rgba(40,42,54,.95);opacity:0;pointer-events:none;transition:opacity .2s;}',
        '#dr-drop-overlay.show{opacity:1;pointer-events:auto;}',
        '#dr-drop-overlay .dr-box{text-align:center;border:3px dashed #50fa7b;padding:52px 74px;border-radius:22px;background:rgba(30,31,41,.8);}',
        '#dr-drop-overlay .dr-ico{font-size:64px;margin-bottom:16px;}',
        '#dr-drop-overlay .dr-tx{font-size:24px;font-weight:600;margin-bottom:8px;}',
        '#dr-drop-overlay .dr-hi{font-size:14px;color:#6272a4;}',

        /* 滚动条 */
        '.dr-pane::-webkit-scrollbar,.dr-statspanel::-webkit-scrollbar,.dr-colpanel::-webkit-scrollbar{width:10px;height:10px;}',
        '.dr-pane::-webkit-scrollbar-track,.dr-statspanel::-webkit-scrollbar-track{background:#1e1f29;}',
        '.dr-pane::-webkit-scrollbar-thumb,.dr-statspanel::-webkit-scrollbar-thumb,.dr-colpanel::-webkit-scrollbar-thumb{',
        'background:#44475a;border-radius:5px;border:2px solid #1e1f29;}',
        '.dr-pane::-webkit-scrollbar-thumb:hover{background:#6272a4;}',

        '#dr-drop-overlay,#dr-drop-overlay *{box-sizing:border-box;}'
    ].join('\n');

    let stylesInjected = false;
    function injectStyles() {
        if (stylesInjected) return;
        stylesInjected = true;
        try {
            if (typeof GM_addStyle === 'function') { GM_addStyle(CSS); return; }
        } catch (e) { /* 走兜底 */ }
        const st = document.createElement('style');
        st.textContent = CSS;
        (document.head || document.documentElement).appendChild(st);
    }

    /** 声明当前页面归本脚本。markdown-reader 接管时会改成 markdown，守卫看到就停手。 */
    function claimReader() {
        try { document.documentElement.dataset.fileReader = 'data'; } catch (e) { /* 忽略 */ }
    }

    function readerStillOurs() {
        try { return document.documentElement.dataset.fileReader === 'data'; } catch (e) { return false; }
    }

    /* ============================================================
     * 4. 界面
     * ============================================================ */

    function buildUi() {
        const existing = document.getElementById(ROOT_ID);
        if (existing && existing.parentNode === document.body) return;   // 已经好好挂着，别重复建
        if (existing) existing.remove();                                 // 被塞到奇怪的位置，拆了重来

        // 关键：先把原文抓到手，再动 DOM。
        // 原来这里是先 innerHTML='' 把 body 清了，之后再去读 ，读到的永远是空的。
        // 只在「这个页面本身就是数据文件」时抓。 出现在别人的网页上时，抓来的是页面文案不是文件。
        if (autoTarget()) captureSource();
        claimReader();

        injectStyles();

        document.body.innerHTML = '';
        document.documentElement.style.height = '100%';

        const root = document.createElement('div');
        root.className = 'dr-root';
        root.id = ROOT_ID;

        // ---- 顶部工具条 ----
        const top = document.createElement('div');
        top.className = 'dr-topbar';
        top.innerHTML = [
            'JSON',
            'data',
            '',
            '',
            '',
            '',
            '',
            '',
            '',
            '',
            '',
            '',
            ''
        ].join('');

        // ---- 列显隐面板 ----
        const colPanel = document.createElement('div');
        colPanel.className = 'dr-colpanel';
        colPanel.hidden = true;

        // ---- 统计面板 ----
        const statPanel = document.createElement('div');
        statPanel.className = 'dr-statspanel';
        statPanel.hidden = true;

        // ---- 分屏 ----
        const split = document.createElement('div');
        split.className = 'dr-split';

        const left = document.createElement('div');
        left.className = 'dr-pane dr-pane-left';
        left.setAttribute('data-ref', 'left');

        const splitter = document.createElement('div');
        splitter.className = 'dr-splitter';

        const right = document.createElement('div');
        right.className = 'dr-pane dr-pane-right';
        const editor = document.createElement('textarea');
        editor.className = 'dr-editor';
        editor.spellcheck = false;
        editor.setAttribute('data-ref', 'editor');
        editor.setAttribute('wrap', 'off');
        right.appendChild(editor);

        split.appendChild(left);
        split.appendChild(splitter);
        split.appendChild(right);

        // ---- 分页条 ----
        const foot = document.createElement('div');
        foot.className = 'dr-foot';
        foot.setAttribute('data-ref', 'foot');

        root.appendChild(top);
        root.appendChild(statPanel);
        root.appendChild(split);
        root.appendChild(foot);
        document.body.appendChild(root);

        // ---- 拖放遮罩 ----
        const overlay = document.createElement('div');
        overlay.id = 'dr-drop-overlay';
        overlay.innerHTML = [
            '',
            '  { }',
            '  将 JSON / CSV 文件拖放到此处',
            '  支持 .json .csv .tsv',
            ''
        ].join('');
        document.body.appendChild(overlay);

        root.querySelectorAll('[data-ref]').forEach(function (el) {
            refs[el.getAttribute('data-ref')] = el;
        });
        refs.root = root;
        refs.top = top;
        refs.colPanel = colPanel;
        refs.statPanel = statPanel;
        refs.left = left;
        refs.right = right;
        refs.editor = editor;
        refs.splitter = splitter;
        refs.foot = foot;
        refs.overlay = overlay;

        document.body.appendChild(colPanel);
        bindUi();
    }

    /* ============================================================
     * 5. 渲染
     * ============================================================ */

    function visibleHeaders() {
        const m = state.model;
        if (!m || m.kind !== 'json' && m.kind !== 'csv') return [];
        return m.headers.filter(function (h) { return !state.hidden[h]; });
    }

    function compareVals(a, b, type) {
        if (a === undefined && b === undefined) return 0;
        if (a === undefined) return 1;       // 空值恒排最后
        if (b === undefined) return -1;
        if (type === 'number') return a - b;
        if (type === 'boolean') return (a ? 1 : 0) - (b ? 1 : 0);
        return String(a).localeCompare(String(b), undefined, { numeric: true, sensitivity: 'base' });
    }

    /** 应用搜索 + 排序，返回 { indexes, rows } */
    function buildView() {
        const m = state.model;
        const headers = visibleHeaders();
        const idx = headers.map(function (h) { return m.headers.indexOf(h); });

        const q = state.query.trim().toLowerCase();
        const keep = [];
        for (let r = 0; r < m.rows.length; r++) {
            if (q) {
                let hit = false;
                for (let c = 0; c < idx.length; c++) {
                    if (cellText(m.rows[r][idx[c]]).toLowerCase().indexOf(q) >= 0) { hit = true; break; }
                }
                if (!hit) continue;
            }
            keep.push(r);
        }

        if (state.sortKey && state.sortDir) {
            const ci = m.headers.indexOf(state.sortKey);
            if (ci >= 0) {
                const type = (m.types && m.types[state.sortKey]) || 'string';
                const dir = state.sortDir;
                keep.sort(function (x, y) {
                    const d = compareVals(castVal(m.rows[x][ci], type), castVal(m.rows[y][ci], type), type);
                    return d !== 0 ? d * dir : x - y;      // 同值时保持原始顺序
                });
            }
        }
        return { indexes: idx, rows: keep };
    }

    /* 一次渲染会用到筛选结果好几遍（表头 / 表格 / 分页 / 统计），
       5 万行时每遍都是全表扫描，所以按状态签名缓存一份。 */
    let viewCache = { key: null, val: null };
    let modelSeq = 0;

    function viewKey() {
        const m = state.model;
        if (!m) return 'none';
        let hid = '';
        for (const k of Object.keys(state.hidden)) if (state.hidden[k]) hid += k + '\u0001';
        return [m.__id, state.query, state.sortKey, state.sortDir, hid].join('\u0000');
    }

    function getView() {
        const key = viewKey();
        if (viewCache.key === key) return viewCache.val;
        const val = buildView();
        viewCache = { key: key, val: val };
        return val;
    }

    function columnStats() {
        const m = state.model;
        const view = getView();
        const hasNum = m.headers.some(function (h) { return (m.types && m.types[h]) === 'number'; });
        const hasBool = m.headers.some(function (h) { return (m.types && m.types[h]) === 'boolean'; });
        const canDistinct = view.rows.length <= 20000;
        const out = [];
        m.headers.forEach(function (h, ci) {
            const type = (m.types && m.types[h]) || 'string';
            let nonEmpty = 0, sum = 0, mn = Infinity, mx = -Infinity, tCount = 0, fCount = 0;
            const seen = (type === 'string' && canDistinct) ? Object.create(null) : null;
            for (let i = 0; i < view.rows.length; i++) {
                const v = castVal(m.rows[view.rows[i]][ci], type);
                if (v === undefined) continue;
                nonEmpty++;
                if (type === 'number') { sum += v; if (v < mn) mn = v; if (v > mx) mx = v; }
                else if (type === 'boolean') { if (v) tCount++; else fCount++; }
                else if (seen) { seen[String(v)] = 1; }
            }
            out.push({
                name: h, type: type, nonEmpty: nonEmpty, viewRows: view.rows.length,
                distinct: seen ? Object.keys(seen).length : null,
                sum: sum,
                min: type === 'number' ? (nonEmpty ? mn : null) : null,
                max: type === 'number' ? (nonEmpty ? mx : null) : null,
                tCount: tCount, fCount: fCount
            });
        });
        return { stats: out, viewRows: view.rows.length, hasNum: hasNum, hasBool: hasBool, canDistinct: canDistinct };
    }

    function fmtNum(n) {
        if (n === null || n === undefined || !isFinite(n)) return '—';
        if (Number.isInteger(n)) return n.toLocaleString('en-US');
        return Number(n.toFixed(4)).toLocaleString('en-US');
    }

    function typeLabel(t) {
        return t === 'number' ? '数字' : t === 'boolean' ? '布尔' : '文本';
    }

    function renderTable() {
        const m = state.model;
        const left = refs.left;

        if (state.error) {
            left.innerHTML = [
                '解析失败',
                escapeHtml(state.error),
                '左侧预览已暂停，右侧原文可继续编辑；改好后点「重新解析」。',
                ''
            ].join('');
            return;
        }

        if (!m) {
            left.innerHTML = [
                '',
                '  { }',
                '  拖入 .json / .csv / .tsv 文件，或点右上角「列」旁的编辑区直接粘贴内容',
                ''
            ].join('');
            return;
        }

        if (m.kind === 'tree') {
            left.innerHTML = '' + renderTree(m.jsonValue, 0) + '';
            return;
        }

        if (!m.rows.length) {
            left.innerHTML = [
                '',
                '  ∅',
                '  ' + escapeHtml(state.format === 'json' ? '这个 JSON 是个空数组 []' : 'CSV 只有表头，没有数据行') + '',
                ''
            ].join('');
            return;
        }

        const headers = visibleHeaders();
        const view = getView();
        const rows = view.rows;
        const total = m.rows.length;
        const pages = Math.max(1, Math.ceil(rows.length / state.pageSize));
        if (state.page > pages) state.page = pages;
        const from = (state.page - 1) * state.pageSize;
        const pageRows = rows.slice(from, from + state.pageSize);

        const html = ['',
            ''];

        headers.forEach(function (h) {
            const type = (m.types && m.types[h]) || 'string';
            const arrow = state.sortKey === h && state.sortDir
                ? '' + (state.sortDir > 0 ? '▲' : '▼') + '' : '';
            html.push('');
        });
        html.push('');

        for (let i = 0; i < pageRows.length; i++) {
            const srcRow = m.rows[pageRows[i]];
            html.push('');
            for (let c = 0; c < headers.length; c++) {
                const ci = m.headers.indexOf(headers[c]);
                const raw = srcRow[ci];
                const type = (m.types && m.types[headers[c]]) || 'string';
                const text = cellText(raw);
                let cls = '';
                if (raw === null) cls = 'dr-null';
                else if (raw !== undefined && typeof raw === 'object') cls = 'dr-deep';
                else if (type === 'number') cls = 'dr-num';
                else if (type === 'boolean') cls = 'dr-bool';
                const title = cellTitle(raw);
                html.push('');
            }
            html.push('');
        }
        html.push('# ' +
                escapeHtml(h) + arrow + '' + typeLabel(type) + '
' + (pageRows[i] + 1) + ' ' +
                    escapeHtml(text) + '');
        left.innerHTML = html.join('');
    }

    /** 非数组 JSON 的可折叠树 */
    function renderTree(v, depth) {
        const open = depth < 2 ? ' open' : '';
        if (v === null) return 'null';
        if (Array.isArray(v)) {
            if (!v.length) return '[]';
            return 'Array' +
                '' + v.length + ' 项' +
                v.map(function (x, i) { return '' + renderTree(x, depth + 1) + ''; }).join('') +
                '';
        }
        if (typeof v === 'object') {
            const keys = Object.keys(v);
            if (!keys.length) return '{}';
            return 'Object' +
                '' + keys.length + ' 键' +
                keys.map(function (k) {
                    return '' + escapeHtml(k) + ': ' +
                        renderTree(v[k], depth + 1) + '';
                }).join('') +
                '';
        }
        if (typeof v === 'string') return '"' + escapeHtml(v) + '"';
        if (typeof v === 'number') return '' + escapeHtml(String(v)) + '';
        if (typeof v === 'boolean') return '' + escapeHtml(String(v)) + '';
        return escapeHtml(String(v));
    }

    function renderHead() {
        const m = state.model;
        const isCsv = state.format !== 'json';
        refs.badge.textContent = isCsv ? state.format.toUpperCase() : 'JSON';
        refs.badge.className = 'dr-badge' + (isCsv ? ' dr-badge-csv' : '');
        refs.name.textContent = state.fileName;
        refs.dirty.textContent = state.text === state.original ? '' : '● 未保存';

        if (state.error) {
            refs.meta.textContent = state.text.length.toLocaleString('en-US') + ' 字符 · 解析失败';
        } else if (!m) {
            refs.meta.textContent = '';
        } else if (m.kind === 'tree') {
            refs.meta.textContent = '顶层不是数组，已用树视图展示';
        } else if (!m.rows.length) {
            refs.meta.textContent = (m.headers || []).length + ' 列 · 0 行';
        } else {
            const filtered = state.query.trim() ? getView().rows.length : m.rows.length;
            refs.meta.textContent = (m.headers || []).length + ' 列 · ' +
                m.rows.length.toLocaleString('en-US') + ' 行' +
                (filtered !== m.rows.length ? '（筛出 ' + filtered.toLocaleString('en-US') + '）' : '');
        }
    }

    function renderFoot() {
        const m = state.model;
        if (state.error || !m || m.kind === 'tree') { refs.foot.innerHTML = ''; return; }
        const rows = m.rows.length;
        if (!rows) { refs.foot.innerHTML = ''; return; }

        const view = getView();
        const filtered = view.rows.length;
        const pages = Math.max(1, Math.ceil(filtered / state.pageSize));
        const from = (state.page - 1) * state.pageSize;
        const shownFrom = filtered ? from + 1 : 0;
        const shownTo = Math.min(filtered, from + state.pageSize);

        refs.foot.innerHTML = [
            '显示 ' + shownFrom.toLocaleString('en-US') + '–' + shownTo.toLocaleString('en-US') +
            ' / 筛选后 ' + filtered.toLocaleString('en-US') + ' / 总计 ' +
            rows.toLocaleString('en-US') + ' 行',
            '',
            '每页 ',
            '第 ' + state.page + ' / ' + pages + ' 页',
            '',
            '',
            '',
            ''
        ].join('');
    }

    function renderStats() {
        if (!state.showStats) { refs.statPanel.hidden = true; return; }
        const m = state.model;
        if (state.error || !m || m.kind === 'tree') {
            refs.statPanel.hidden = false;
            refs.statPanel.innerHTML = '' +
                (state.error ? '解析失败，无法统计。' : '树视图不提供列统计。') + '';
            return;
        }
        refs.statPanel.hidden = false;
        const r = state.stats || (state.stats = columnStats());

        const head = ['列', '类型', '非空', '缺失'];
        if (r.hasNum) head.push('最小', '最大', '平均', '合计');
        if (r.hasBool) head.push('true', 'false');
        if (r.canDistinct) head.push('不同值');

        const body = r.stats.map(function (s) {
            const td = ['' + escapeHtml(s.name) + '',
                '' + typeLabel(s.type) + '',
                '' + s.nonEmpty.toLocaleString('en-US') + '',
                '' + (s.viewRows - s.nonEmpty).toLocaleString('en-US') + ''];
            if (r.hasNum) {
                td.push('' + fmtNum(s.min) + '', '' + fmtNum(s.max) + '',
                    '' + fmtNum(s.nonEmpty ? s.sum / s.nonEmpty : null) + '',
                    '' + fmtNum(s.sum) + '');
            }
            if (r.hasBool) {
                td.push('' + s.tCount.toLocaleString('en-US') + '',
                    '' + s.fCount.toLocaleString('en-US') + '');
            }
            if (r.canDistinct) td.push('' + (s.distinct === null ? '—' : s.distinct.toLocaleString('en-US')) + '');
            return '' + td.join('') + '';
        }).join('');

        refs.statPanel.innerHTML =
            '' + head.join('') + '' + body + '
';
    }

    function renderColPanel() {
        const m = state.model;
        if (!m || (m.kind !== 'json' && m.kind !== 'csv')) { refs.colPanel.hidden = true; return; }
        refs.colPanel.innerHTML = ['显示的列（' + visibleHeaders().length + '/' + m.headers.length + '）']
            .concat(m.headers.map(function (h) {
                const on = !state.hidden[h];
                const type = (m.types && m.types[h]) || 'string';
                return '' + escapeHtml(h) + '' + typeLabel(type) + '';
            }))
            .concat(['',
                '全选'])
            .join('');
    }

    function renderAll() {
        state.stats = null;
        renderHead();
        renderTable();
        renderFoot();
        renderStats();
        renderColPanel();
        const btn = refs.top.querySelector('[data-act="stats"]');
        if (btn) btn.classList.toggle('on', state.showStats);
    }

    /* ============================================================
     * 6. 解析调度 / 加载 / 保存
     * ============================================================ */

    function reparse(keepView) {
        const text = refs.editor ? refs.editor.value : state.text;
        state.text = text;
        state.stats = null;
        try {
            state.model = parseData(text, state.fileName);
            state.model.__id = ++modelSeq;      // 换模型 = 缓存作废
            state.error = '';
            // 换了文件结构时，清掉不再存在的排序列
            if (state.sortKey && state.model.headers && state.model.headers.indexOf(state.sortKey) < 0) {
                state.sortKey = null;
                state.sortDir = 0;
            }
        } catch (e) {
            state.model = null;
            state.error = (e && e.message) ? e.message : String(e);
        }
        if (!keepView) state.page = 1;
        renderAll();
    }

    function scheduleReparse() {
        clearTimeout(state.debounceTimer);
        state.debounceTimer = setTimeout(function () { reparse(true); }, PREVIEW_DEBOUNCE);
    }

    function loadText(text, fileName) {
        state.fileName = fileName || 'data';
        state.original = stripBom(String(text == null ? '' : text));
        state.text = state.original;
        state.query = '';
        state.sortKey = null;
        state.sortDir = 0;
        state.page = 1;
        state.hidden = {};
        state.stats = null;
        state.format = extOf(state.fileName) === 'csv' || extOf(state.fileName) === 'tsv'
            ? (extOf(state.fileName) === 'tsv' ? 'tsv' : 'csv') : 'json';

        // 内容已经就位，拖放遮罩没有存在意义了（拖进来 / 自动解析两条路径都要收）
        showOverlay(false);
        if (refs.colPanel) refs.colPanel.hidden = true;

        // 换文件时把编辑区整体换掉
        const ta = refs.editor;
        const pos = { top: ta.scrollTop, left: ta.scrollLeft };
        ta.value = state.original;
        ta.scrollTop = pos.top;
        ta.scrollLeft = pos.left;
        if (refs.search) refs.search.value = '';
        reparse(false);
    }

    async function loadFile(file) {
        if (!file) return;
        const ext = extOf(file.name);
        if (EXT_DATA.indexOf(ext) < 0) {
            alert('只支持 .json / .csv / .tsv 文件！');
            return;
        }
        if (state.text !== state.original && !confirm('当前内容有未保存的修改，确定丢弃并打开 ' + file.name + ' 吗？')) return;
        ensureUi();
        try {
            const buf = await file.arrayBuffer();
            loadText(decodeText(new Uint8Array(buf)), file.name);
        } catch (e) {
            alert('读取文件失败：' + (e && e.message ? e.message : e));
        }
    }

    function pickFiles() {
        const input = document.createElement('input');
        input.type = 'file';
        input.accept = '.json,.csv,.tsv';
        input.style.display = 'none';
        input.addEventListener('change', function () {
            const f = input.files && input.files[0];
            try { input.remove(); } catch (e) { /* 忽略 */ }
            if (f) loadFile(f);
        });
        document.body.appendChild(input);
        input.click();
    }

    /** 按目标格式拿到最终要写出的文本 */
    function buildOutput(fmt) {
        const target = fmt || 'origin';
        const srcFormat = state.format;
        const wantJson = target === 'json' || (target === 'origin' && srcFormat === 'json');

        // 解析失败时不猜，直接把原文原样写出去，绝不吞掉用户内容
        if (state.error || !state.model) {
            return { text: state.text, ext: srcFormat === 'csv' ? 'csv' : (srcFormat === 'tsv' ? 'tsv' : 'json') };
        }

        const m = state.model;
        if (wantJson) {
            if (m.kind === 'json' || m.kind === 'tree') {
                return { text: JSON.stringify(m.jsonValue, null, 2), ext: 'json' };
            }
            return { text: JSON.stringify(tableToJson(m), null, 2), ext: 'json' };
        }
        // 树视图 / JSON → CSV：把对象数组铺平成表
        if (m.kind === 'json') {
            const flat = modelFromJson(m.jsonValue);
            if (flat.kind !== 'json' || !flat.headers.length) {
                return { text: toCsv({ headers: ['值'], rows: [m.jsonValue].map(function (r) { return [r]; }), types: {} }, ','), ext: 'csv' };
            }
            return { text: toCsv(flat, ','), ext: 'csv' };
        }
        return { text: toCsv(m, m.delim), ext: target === 'csv' ? 'csv' : srcFormat };
    }

    function save(fmt) {
        const out = buildOutput(fmt);
        if (!out.text) return;
        const name = baseName(state.fileName) + '.' + out.ext;
        const mime = out.ext === 'json' ? 'application/json;charset=utf-8' : 'text/csv;charset=utf-8';
        downloadBlob(new Blob([out.text], { type: mime }), name);

        // 只有「按原格式保存」才认为已保存，格式转换另存不覆盖当前编辑状态
        if (!fmt || fmt === 'origin') {
            state.original = out.text;
            state.text = out.text;
            if (refs.editor) refs.editor.value = out.text;
            renderHead();
        }
    }

    /* ============================================================
     * 7. 事件
     * ============================================================ */

    function onAction(act) {
        switch (act) {
            case 'save': save(undefined); break;
            case 'reparse': reparse(false); break;
            case 'revert':
                if (state.text !== state.original && !confirm('确定丢弃所有修改，回到载入时的内容吗？')) return;
                if (refs.editor) refs.editor.value = state.original;
                reparse(false);
                break;
            case 'stats':
                state.showStats = !state.showStats;
                renderAll();
                break;
            case 'cols':
                refs.colPanel.hidden = !refs.colPanel.hidden;
                break;
            case 'first': state.page = 1; renderTable(); renderFoot(); break;
            case 'prev': if (state.page > 1) { state.page--; renderTable(); renderFoot(); } break;
            case 'next': if (state.page * state.pageSize < getView().rows.length) { state.page++; renderTable(); renderFoot(); } break;
            case 'last': state.page = Math.max(1, Math.ceil(getView().rows.length / state.pageSize)); renderTable(); renderFoot(); break;
            case 'pick': pickFiles(); break;
            default: break;
        }
    }

    function bindUi() {
        // 界面可能被浏览器的查看器冲掉后重建，这些 document 级监听不能重复挂
        if (bindUi._done) return;
        bindUi._done = true;

        // 顶部按钮 + 分页条按钮统一委托
        document.addEventListener('click', function (e) {
            const el = e.target && e.target.closest ? e.target.closest('[data-act]') : null;
            if (!el) return;
            const act = el.dataset.act;

            if (act === 'pagesize') return;               // change 事件处理
            if (act === 'save' || act === 'reparse' || act === 'revert' || act === 'stats' || act === 'cols' || act === 'pick') {
                e.preventDefault();
                onAction(act);
                return;
            }
            if (act === 'first' || act === 'prev' || act === 'next' || act === 'last') {
                e.preventDefault();
                if (!el.disabled) onAction(act);
                return;
            }
            // 点表格头排序
            if (el.tagName === 'TH' && el.dataset.sort !== undefined) {
                const key = el.dataset.sort;
                if (state.sortKey === key) {
                    if (state.sortDir === 1) state.sortDir = -1;
                    else if (state.sortDir === -1) { state.sortDir = 0; state.sortKey = null; }
                } else {
                    state.sortKey = key;
                    state.sortDir = 1;
                }
                state.page = 1;
                renderTable();
                renderFoot();
            }
        });

        // 分页条里的每页条数
        document.addEventListener('change', function (e) {
            const el = e.target;
            if (!el || el.dataset.act !== 'pagesize') return;
            state.pageSize = Number(el.value) || DEFAULT_PAGE;
            state.page = 1;
            renderTable();
            renderFoot();
        });

        // 列显隐
        document.addEventListener('change', function (e) {
            const el = e.target;
            if (!el || !el.dataset || el.dataset.col === undefined) return;
            const m = state.model;
            if (!m || !m.headers.length) return;
            const col = el.dataset.col;

            if (col === '__all') {
                state.hidden = {};
                // 全不勾选会得到一张空表没法恢复，所以至少保留第一列
                if (!el.checked) m.headers.forEach(function (h, i) { if (i > 0) state.hidden[h] = true; });
            } else if (el.checked) {
                delete state.hidden[col];
            } else {
                state.hidden[col] = true;
            }
            state.stats = null;
            renderColPanel();
            renderTable();
            renderFoot();
            renderStats();
        });

        // 点击面板外关闭列面板
        document.addEventListener('mousedown', function (e) {
            if (refs.colPanel.hidden) return;
            if (refs.colPanel.contains(e.target)) return;
            const btn = e.target && e.target.closest ? e.target.closest('[data-act="cols"]') : null;
            if (btn) return;
            refs.colPanel.hidden = true;
        });

        // 搜索
        let searchTimer = 0;
        refs.search.addEventListener('input', function () {
            const v = this.value;
            clearTimeout(searchTimer);
            searchTimer = setTimeout(function () {
                state.query = v;
                state.page = 1;
                state.stats = null;
                renderHead();
                renderTable();
                renderFoot();
                renderStats();
            }, 150);
        });

        // 保存格式选择
        refs.top.querySelector('[data-ref="savefmt"]').addEventListener('change', function () {
            save(this.value === 'origin' ? undefined : this.value);
            this.value = 'origin';
        });

        // 编辑区
        refs.editor.addEventListener('input', function () {
            state.text = this.value;
            renderHead();
            scheduleReparse();
        });

        refs.editor.addEventListener('keydown', function (e) {
            // Tab 插入两个空格而不是跳走（缩进敏感格式）
            if (e.key === 'Tab' && !e.ctrlKey && !e.metaKey && !e.altKey) {
                e.preventDefault();
                const ta = e.target;
                const s = ta.selectionStart, en = ta.selectionEnd;
                ta.value = ta.value.slice(0, s) + '  ' + ta.value.slice(en);
                ta.selectionStart = ta.selectionEnd = s + 2;
                state.text = ta.value;
                renderHead();
                scheduleReparse();
                return;
            }
            // Ctrl+S 保存 / Ctrl+Enter 强制重新解析
            if ((e.ctrlKey || e.metaKey) && (e.key === 's' || e.key === 'S')) {
                e.preventDefault();
                save(undefined);
                return;
            }
            if ((e.ctrlKey || e.metaKey) && e.key === 'Enter') {
                e.preventDefault();
                clearTimeout(state.debounceTimer);
                reparse(false);
            }
        });

        // 分割条拖动
        let dragging = false, startX = 0, startW = 0;
        refs.splitter.addEventListener('mousedown', function (e) {
            dragging = true;
            startX = e.clientX;
            startW = refs.left.getBoundingClientRect().width;
            refs.splitter.classList.add('dragging');
            document.body.style.cursor = 'col-resize';
            e.preventDefault();
        });
        document.addEventListener('mousemove', function (e) {
            if (!dragging) return;
            const total = refs.root.querySelector('.dr-split').getBoundingClientRect().width;
            const spW = refs.splitter.getBoundingClientRect().width;
            const w = Math.min(Math.max(startW + (e.clientX - startX), total * 0.1), total * 0.9 - spW);
            refs.left.style.flex = '0 0 ' + w + 'px';
            refs.right.style.flex = '0 0 ' + (total - w - spW) + 'px';
        });
        document.addEventListener('mouseup', function () {
            if (!dragging) return;
            dragging = false;
            refs.splitter.classList.remove('dragging');
            document.body.style.cursor = '';
        });

        // 未保存离开提醒
        window.addEventListener('beforeunload', function (e) {
            if (state.text === state.original) return;
            e.preventDefault();
            e.returnValue = '';
            return '';
        });
    }

    /* ---------------- 拖放：只接管 .json/.csv/.tsv ---------------- */

    function isDataDrag(e) {
        const dt = e.dataTransfer;
        if (!dt) return false;
        const types = dt.types || [];
        for (let i = 0; i < types.length; i++) if (types[i] === 'Files') return true;
        return false;
    }

    /**
     * 拖动中拿文件名；拿不到才看 MIME。
     * MIME 只认 json/csv/tsv 专有类型。application/vnd.ms-excel 是 .xls 的类型，
     * text/plain 又和 markdown 的 .txt 重叠——这两类一旦在 dragover 里 preventDefault，
     * 浏览器就不会打开文件，另一个脚本也收不到这次拖放。
     */
    function dragHasDataFile(e) {
        const dt = e.dataTransfer;
        if (!dt) return false;
        const items = dt.items ? Array.prototype.slice.call(dt.items) : [];
        for (let i = 0; i < items.length; i++) {
            if (items[i].kind && items[i].kind !== 'file') continue;
            let f = null;
            try { f = items[i].getAsFile(); } catch (err) { f = null; }
            if (f && f.name) {
                if (EXT_DATA.indexOf(extOf(f.name)) >= 0) return true;
                continue;
            }
            const type = String(items[i].type || '').toLowerCase().split(';')[0].trim();
            if (type === 'application/json' || type === 'text/json' || type === 'text/csv' ||
                type === 'text/tab-separated-values') return true;
        }
        return false;
    }

    /** 拖放提示层。不走 buildUi，这样在别人的页面上拖一下不会把整页清掉。 */
    function ensureOverlay() {
        if (refs.overlay && refs.overlay.parentNode) return refs.overlay;
        if (!document.body) return null;
        injectStyles();
        const overlay = document.createElement('div');
        overlay.id = 'dr-drop-overlay';
        overlay.innerHTML = [
            '',
            '  { }',
            '  将 JSON / CSV 文件拖放到此处',
            '  支持 .json .csv .tsv',
            ''
        ].join('');
        document.body.appendChild(overlay);
        refs.overlay = overlay;
        return overlay;
    }

    function showOverlay(on) {
        if (on) ensureOverlay();
        if (!refs.overlay) return;
        refs.overlay.classList.toggle('show', !!on);
    }

    function bindDrop() {
        document.addEventListener('dragenter', function (e) {
            if (!isDataDrag(e) || !dragHasDataFile(e)) return;
            e.preventDefault();
            showOverlay(true);
        }, true);
        document.addEventListener('dragover', function (e) {
            if (!isDataDrag(e) || !dragHasDataFile(e)) return;
            e.preventDefault();
            try { e.dataTransfer.dropEffect = 'copy'; } catch (err) { /* 忽略 */ }
        }, true);
        document.addEventListener('dragleave', function (e) {
            // 指针还在页面里时 relatedTarget 有值，这时收起遮罩会闪。
            // 只有真正离开窗口才收。
            if (e.relatedTarget) return;
            showOverlay(false);
        }, true);
        document.addEventListener('drop', function (e) {
            if (!isDataDrag(e)) return;
            showOverlay(false);
            const files = Array.prototype.slice.call((e.dataTransfer && e.dataTransfer.files) || []);
            const hit = files.filter(function (f) { return EXT_DATA.indexOf(extOf(f.name)) >= 0; });
            if (!hit.length) return;                 // 不是数据文件 → 原样放行，浏览器自己处理
            e.preventDefault();
            e.stopPropagation();
            loadFile(hit[0]);
        }, true);
    }

    /* ============================================================
     * 8. 启动
     * ============================================================ */

    /** 当前页面是不是「直接打开的本地数据文件」 */
    function autoTarget() {
        if (location.protocol !== 'file:') return '';      // 不接管 http(s)，避免抢接口页面
        const pathname = decodeURIComponent(location.pathname || '');
        const name = pathname.split('/').pop() || '';
        if (!name || EXT_DATA.indexOf(extOf(name)) < 0) return '';
        return name;
    }

    /** 从浏览器渲染好的页面里取原文（Chrome 把 json/csv 放在  里，JSON 查看器也是建在它旁边） */
    function readPageText() {
        return captureSource();
    }

    function registerMenus() {
        if (typeof GM_registerMenuCommand !== 'function') return;
        try {
            GM_registerMenuCommand('📂 打开 JSON / CSV 文件…', pickFiles);
            GM_registerMenuCommand('💾 保存当前内容', function () { save(undefined); });
            GM_registerMenuCommand('🔄 重新解析', function () { reparse(false); });
        } catch (e) { /* 忽略 */ }
    }

    /** 对外暴露一点口子，方便在控制台/自动化里驱动（和 word-reader.js 的做法一致） */
    function exposeApi() {
        const api = {
            version: VERSION,
            loadText: loadText,
            open: pickFiles,
            save: save,
            reparse: reparse,
            state: state
        };
        try { window.DataReader = api; } catch (e) { /* 忽略 */ }
        try { (typeof unsafeWindow !== 'undefined' ? unsafeWindow : window).DataReader = api; } catch (e) { /* 忽略 */ }
    }

    /**
     * 浏览器自带 JSON 查看器会重建 body 把界面冲掉。
     * 这里盯着 document，一旦发现自己的根节点没了就按快照重新挂回去。
     * 用 rAF 合并：一帧内几十次 DOM 变动只做一次检查，不会卡。
     */
    function guardNativeViewer() {
        let scheduled = false;
        let observer = null;
        const check = function () {
            scheduled = false;
            // markdown / word 已经声明接管时，不要把界面盖回去。
            if (!readerStillOurs()) {
                try { if (observer) observer.disconnect(); } catch (e) { /* 忽略 */ }
                return;
            }
            const root = document.getElementById(ROOT_ID);
            // 根节点必须直接挂在 body 下才算「界面还在」。
            // 被浏览器连同  一起重新插到别处，也当失效处理，重新挂一次。
            if (!root || root.parentNode !== document.body) remount();
            else killNativeViewer();
        };
        const schedule = function () {
            if (scheduled) return;
            scheduled = true;
            const raf = window.requestAnimationFrame || function (fn) { setTimeout(fn, 16); };
            raf(check);
        };
        try {
            observer = new MutationObserver(schedule);
            observer.observe(document.documentElement, {
                childList: true,
                subtree: true
            });
        } catch (e) { /* 忽略 */ }
    }

    /** 界面被冲掉后重建：用已经抓在手里的正文快照恢复 */
    function remount() {
        const fileName = state.fileName;
        buildUi();
        killNativeViewer();
        // 已经载入过的内容优先（用户可能改过）。页面原文快照只用于「还没 loadText 就被浏览器冲掉」。
        if (state.text) {
            loadText(state.text, fileName);
        } else if (capturedSource && capturedSource.trim() && fileName && fileName !== 'data') {
            loadText(capturedSource, fileName);
        } else {
            renderAll();
            showOverlay(true);
        }
    }

    /** 取不到原文时也照样给出界面（错误面板本身就是指引），绝不留一片空白让人以为脚本没装 */
    function showEmptyState(auto, msg) {
        state.fileName = auto;
        state.format = extOf(auto) === 'json' ? 'json' : extOf(auto);
        state.error = msg;
        state.text = '';
        state.model = null;
        refs.editor.value = '';
        renderAll();
    }

    function startAutoContent(text, auto) {
        if (text.length > MAX_AUTO_PARSE) {
            showEmptyState(auto, '文件超过 64 MB，已跳过自动解析。可以把内容粘贴到右侧再点「重新解析」。');
            showOverlay(true);
            return;
        }
        loadText(text, auto);
    }

    let viewerGuarding = false;
    function ensureUi() {
        if (!document.body) return;
        buildUi();
        if (viewerGuarding) return;
        viewerGuarding = true;
        guardNativeViewer();
    }

    function bufferToText(buf) {
        if (buf == null || buf === '') return '';
        if (typeof buf === 'string') return buf;
        try {
            if (buf instanceof ArrayBuffer) return decodeText(new Uint8Array(buf));
            if (typeof ArrayBuffer !== 'undefined' && ArrayBuffer.isView && ArrayBuffer.isView(buf)) {
                return decodeText(new Uint8Array(buf.buffer, buf.byteOffset, buf.byteLength));
            }
        } catch (e) { /* 忽略 */ }
        return '';
    }

    /** 页面自己的 XHR。油猴沙箱里的 XHR 经常读不到 file://，必须借页面的。 */
    function pageXhr(url, done, binary) {
        const XHR = (typeof unsafeWindow !== 'undefined' && unsafeWindow && unsafeWindow.XMLHttpRequest)
            ? unsafeWindow.XMLHttpRequest
            : XMLHttpRequest;
        let xhr;
        try { xhr = new XHR(); } catch (e) { done(''); return; }
        try { xhr.open('GET', url, true); } catch (e) { done(''); return; }
        if (binary) { try { xhr.responseType = 'arraybuffer'; } catch (e) { /* 退回文本 */ } }
        xhr.onload = function () {
            if (xhr.status && xhr.status !== 200 && xhr.status !== 0) { done(''); return; }
            if (binary) {
                const text = bufferToText(xhr.response);
                if (text && text.trim()) { done(text); return; }
                pageXhr(url, done, false);
                return;
            }
            done(xhr.responseText || '');
        };
        xhr.onerror = function () {
            if (binary) pageXhr(url, done, false);
            else done('');
        };
        try { xhr.send(); } catch (e) {
            if (binary) pageXhr(url, done, false);
            else done('');
        }
    }

    /**
     * 按文件地址把字节读回来。
     * Chrome / Edge 打开 .csv 时经常不生成 （JSON 才有内置查看器），
     * 只盯着 DOM 就会什么都不解析。
     */
    function readFileUrl(url, done) {
        let settled = false;
        const finish = function (text) {
            if (settled) return;
            settled = true;
            try { done(text || ''); } catch (e) { /* 忽略 */ }
        };
        pageXhr(url, function (text) {
            if (text && String(text).trim()) { finish(text); return; }
            if (typeof GM_xmlhttpRequest !== 'function') { finish(''); return; }
            try {
                GM_xmlhttpRequest({
                    method: 'GET',
                    url: url,
                    responseType: 'arraybuffer',
                    timeout: 20000,
                    onload: function (res) {
                        const bufText = bufferToText(res && res.response);
                        finish(bufText || (res && res.responseText) || '');
                    },
                    onerror: function () { finish(''); },
                    ontimeout: function () { finish(''); }
                });
            } catch (e) { finish(''); }
        }, true);
    }

    function init() {
        // 拖放监听在所有页面都挂上。界面只在确认是本地数据文件，或用户真的拖入了数据文件时才建。
        bindDrop();
        registerMenus();
        exposeApi();

        const auto = autoTarget();
        if (!auto) return;

        // 读到原文再铺界面。提前 buildUi 会把  清掉，后面就补不回来了。
        const bootFromText = function (text) {
            if (!text || !text.trim()) return false;
            capturedSource = text;
            ensureUi();
            startAutoContent(text, auto);
            return true;
        };
        const fail = function () {
            ensureUi();
            showEmptyState(auto, '没能从这个页面读到文件原文（浏览器可能把它当成下载处理了）。'
                + '点「📂 打开」选择文件，或直接把 ' + auto + ' 拖进这个页面。');
        };

        // JSON 查看器同步就把原文放进 ，这条路径不能改成异步，否则会被它抢先冲掉。
        if (bootFromText(captureSource(true))) return;

        readFileUrl(location.href, function (text) {
            if (bootFromText(text) || bootFromText(captureSource(true))) return;
            fail();
        });
    }

    if (document.readyState === 'loading') {
        document.addEventListener('DOMContentLoaded', init, { once: true });
    } else {
        init();
    }
})();