diff --git a/pdf-sign.html b/pdf-sign.html
new file mode 100644
index 0000000..6f97723
--- /dev/null
+++ b/pdf-sign.html
@@ -0,0 +1,628 @@
+<!DOCTYPE html>
+<html lang="zh-TW">
+<head>
+  <meta charset="UTF-8" />
+  <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+  <title>PDF 簽名工具</title>
+  <script src="https://cdn.tailwindcss.com"></script>
+  <script src="https://cdnjs.cloudflare.com/ajax/libs/pdf.js/3.11.174/pdf.min.js"></script>
+  <script src="https://unpkg.com/pdf-lib@1.17.1/dist/pdf-lib.min.js"></script>
+
+  <!-- type="text/tailwindcss" required for @apply to work with Play CDN -->
+  <style type="text/tailwindcss">
+    /* ── Floating signature wrapper ───────────────────────────── */
+    .sig-el {
+      position: absolute; cursor: move; user-select: none;
+    }
+    .sig-el:hover { outline: 2px dashed #3b82f6; outline-offset: 2px; }
+    .sig-el:hover .sig-del  { display: flex !important; }
+    .sig-el:hover .sig-rs   { display: block !important; }
+
+    /* Resize handles */
+    .sig-rs {
+      display: none; position: absolute;
+      width: 10px; height: 10px;
+      background: #3b82f6; border: 2px solid #fff;
+      border-radius: 2px; z-index: 10;
+    }
+    .sig-rs-nw { top:-5px; left:-5px;  cursor:nw-resize; }
+    .sig-rs-ne { top:-5px; right:-5px; cursor:ne-resize; }
+    .sig-rs-sw { bottom:-5px; left:-5px;  cursor:sw-resize; }
+    .sig-rs-se { bottom:-5px; right:-5px; cursor:se-resize; }
+
+    /* Delete button */
+    .sig-del {
+      display: none; position: absolute;
+      top:-12px; right:-12px; width:22px; height:22px;
+      background:#ef4444; border-radius:50%;
+      align-items:center; justify-content:center;
+      color:#fff; font-size:12px; cursor:pointer;
+      z-index:10; border:2px solid #fff;
+    }
+
+    /* ── Toolbar buttons ──────────────────────────────────────── */
+    .tbtn {
+      @apply px-3 py-1.5 rounded-lg text-sm font-medium transition cursor-pointer select-none;
+    }
+    .tbtn-blue   { @apply tbtn bg-blue-500   hover:bg-blue-600   text-white; }
+    .tbtn-green  { @apply tbtn bg-emerald-500 hover:bg-emerald-600 text-white; }
+    .tbtn-purple { @apply tbtn bg-violet-500  hover:bg-violet-600  text-white; }
+    .tbtn-orange { @apply tbtn bg-orange-500  hover:bg-orange-600  text-white; }
+    .tbtn-gray   {
+      @apply tbtn bg-slate-100 hover:bg-slate-200 text-slate-600;
+    }
+    .tbtn-gray:disabled { @apply opacity-40 cursor-not-allowed; }
+
+    /* ── Pen type buttons ─────────────────────────────────────── */
+    .pen-btn {
+      @apply px-3 py-1.5 rounded-lg text-sm font-medium border-2 border-transparent
+             bg-slate-100 text-slate-600 transition cursor-pointer;
+    }
+    .pen-btn.active { @apply border-blue-500 bg-blue-50 text-blue-700; }
+
+    /* ── Color dot buttons ────────────────────────────────────── */
+    .cdot {
+      @apply w-9 h-9 rounded-full border-2 border-white shadow cursor-pointer
+             transition ring-2 ring-transparent ring-offset-1;
+    }
+    .cdot.active { @apply ring-blue-500; }
+
+    /* ── Small action buttons inside modal ───────────────────── */
+    .mbtn-red  { @apply px-4 py-1.5 rounded-lg text-sm font-medium bg-red-100  hover:bg-red-200  text-red-600  transition; }
+    .mbtn-gray { @apply px-4 py-1.5 rounded-lg text-sm font-medium bg-slate-100 hover:bg-slate-200 text-slate-600 transition; }
+  </style>
+
+  <style>
+    #pdf-container { position:relative; display:inline-block; line-height:0; }
+    #sig-canvas    { touch-action:none; cursor:crosshair; display:block; }
+    #pdf-scroll    { overflow:auto; max-height:calc(100vh - 180px); }
+  </style>
+</head>
+<body class="bg-slate-100 min-h-screen flex flex-col">
+
+  <!-- ═══════════════ HEADER TOOLBAR ═══════════════ -->
+  <header class="bg-white border-b shadow-sm sticky top-0 z-30">
+    <div class="max-w-screen-xl mx-auto px-4 py-2 flex flex-wrap items-center gap-2">
+      <div class="mr-2">
+        <h1 class="text-base font-bold text-slate-700 leading-tight">📄 PDF 簽名工具</h1>
+        <p class="text-[11px] text-slate-400 leading-tight">開發者：GinoHung</p>
+      </div>
+
+      <label class="tbtn-blue">
+        📂 載入 PDF
+        <input type="file" accept=".pdf" id="upload-pdf" class="hidden" />
+      </label>
+
+      <label class="tbtn-green">
+        🖼️ 匯入簽名圖片
+        <input type="file" accept="image/*" id="upload-sig-img" class="hidden" />
+      </label>
+
+      <button id="btn-open-pad" class="tbtn-purple">✍️ 手寫簽名</button>
+
+      <div class="flex items-center gap-1 ml-auto">
+        <button id="btn-prev" class="tbtn-gray" disabled>← 上頁</button>
+        <span id="page-label" class="text-xs text-slate-500 min-w-[90px] text-center">尚未載入</span>
+        <button id="btn-next" class="tbtn-gray" disabled>下頁 →</button>
+      </div>
+
+      <button id="btn-export" class="tbtn-orange">💾 匯出 PDF</button>
+    </div>
+  </header>
+
+  <!-- ═══════════════ MAIN PDF AREA ═══════════════ -->
+  <main class="flex-1 flex flex-col items-center py-6 px-4">
+
+    <div id="empty-state"
+      class="w-full max-w-2xl flex flex-col items-center justify-center gap-3 h-72
+             border-2 border-dashed border-slate-300 rounded-2xl bg-white
+             text-slate-400 cursor-pointer hover:border-blue-400 transition"
+      onclick="document.getElementById('upload-pdf').click()">
+      <div class="text-5xl">📄</div>
+      <p class="text-lg font-medium">點擊或拖放 PDF 至此處開始</p>
+      <p class="text-sm">支援多頁 PDF・手寫簽名・PNG 圖片簽名</p>
+    </div>
+
+    <div id="pdf-scroll" class="hidden w-full justify-center">
+      <div id="pdf-container" class="shadow-2xl rounded-lg overflow-visible">
+        <canvas id="pdf-canvas" class="block rounded-lg"></canvas>
+      </div>
+    </div>
+  </main>
+
+  <!-- ═══════════════ HANDWRITING MODAL ═══════════════ -->
+  <div id="modal-pad"
+    class="hidden fixed inset-0 bg-black/60 z-50 flex items-center justify-center
+           p-4 backdrop-blur-sm">
+    <div class="bg-white rounded-2xl shadow-2xl w-full max-w-2xl flex flex-col">
+
+      <!-- Header -->
+      <div class="flex items-center justify-between px-5 py-3 border-b">
+        <h2 class="font-bold text-slate-700">✍️ 手寫簽名</h2>
+        <button id="btn-close-pad" class="text-slate-400 hover:text-slate-600 text-2xl leading-none">&times;</button>
+      </div>
+
+      <!-- Toolbar -->
+      <div class="px-5 py-3 border-b flex flex-wrap gap-5 items-end">
+
+        <!-- Pen type -->
+        <div>
+          <p class="text-xs font-semibold text-slate-400 uppercase tracking-wide mb-1.5">筆觸</p>
+          <div class="flex gap-1" id="pen-type-group">
+            <button class="pen-btn active" data-pen="ballpoint">原子筆</button>
+            <button class="pen-btn"        data-pen="fountain" >鋼筆</button>
+            <button class="pen-btn"        data-pen="brush"    >毛筆</button>
+            <button class="pen-btn"        data-pen="pencil"   >鉛筆</button>
+            <button class="pen-btn"        data-pen="marker"   >奇異筆</button>
+          </div>
+        </div>
+
+        <!-- Color -->
+        <div>
+          <p class="text-xs font-semibold text-slate-400 uppercase tracking-wide mb-1.5">顏色</p>
+          <div class="flex gap-2 items-center" id="color-group">
+            <button class="cdot active" data-color="#111111" style="background:#111111;" title="黑色"></button>
+            <button class="cdot"        data-color="#dc2626" style="background:#dc2626;" title="紅色"></button>
+            <button class="cdot"        data-color="#16a34a" style="background:#16a34a;" title="綠色"></button>
+            <button class="cdot"        data-color="#2563eb" style="background:#2563eb;" title="藍色"></button>
+          </div>
+        </div>
+
+        <!-- Stroke width 1–10 -->
+        <div class="flex-1 min-w-[130px]">
+          <p class="text-xs font-semibold text-slate-400 uppercase tracking-wide mb-1.5">
+            粗細 <span id="width-val">3</span> px
+          </p>
+          <input type="range" id="stroke-width" min="1" max="10" value="3"
+            class="w-full accent-blue-500 cursor-pointer" />
+        </div>
+
+      </div>
+
+      <!-- Canvas -->
+      <div class="px-5 py-4">
+        <div class="relative border-2 border-dashed border-slate-200 rounded-xl overflow-hidden bg-white">
+          <canvas id="sig-canvas" width="620" height="280" class="w-full"></canvas>
+          <p id="pad-hint"
+            class="absolute inset-0 flex items-center justify-center
+                   text-slate-300 text-sm pointer-events-none select-none">
+            在此手寫您的簽名…
+          </p>
+        </div>
+      </div>
+
+      <!-- Footer -->
+      <div class="flex justify-between px-5 py-3 border-t">
+        <div class="flex gap-2">
+          <button id="btn-clear" class="mbtn-red" >清除</button>
+          <button id="btn-undo"  class="mbtn-gray">↩ 撤銷</button>
+        </div>
+        <button id="btn-apply" class="tbtn-blue">✓ 套用到 PDF</button>
+      </div>
+    </div>
+  </div>
+
+  <!-- Toast -->
+  <div id="toast"
+    class="hidden fixed bottom-6 right-6 bg-slate-800 text-white text-sm
+           px-5 py-3 rounded-xl shadow-xl z-50">
+  </div>
+
+  <!-- ═══════════════ SCRIPT ═══════════════ -->
+  <script>
+  // ── Setup ────────────────────────────────────────────────────────
+  pdfjsLib.GlobalWorkerOptions.workerSrc =
+    'https://cdnjs.cloudflare.com/ajax/libs/pdf.js/3.11.174/pdf.worker.min.js';
+
+  const state = {
+    pdfJsDoc: null, rawBytes: null, origName: '',
+    curPage: 1, totalPages: 0, renderScale: 1.5,
+    sigs: [], sigId: 0,
+  };
+
+  const pad = {
+    drawing: false, penType: 'ballpoint',
+    color: '#111111', lineWidth: 3,
+    lastX: 0, lastY: 0, lastVel: 0,
+    history: [], hasContent: false,
+  };
+
+  // ── PDF loading ──────────────────────────────────────────────────
+  document.getElementById('upload-pdf').addEventListener('change', async e => {
+    const file = e.target.files[0];
+    if (!file) return;
+    const buf = await file.arrayBuffer();
+    // Slice a copy for pdf-lib export; pass the original to pdf.js
+    // (pdf.js worker may transfer/detach the ArrayBuffer it receives)
+    state.rawBytes  = new Uint8Array(buf.slice(0));
+    state.origName  = file.name.replace(/\.pdf$/i, '');
+    try {
+      state.pdfJsDoc   = await pdfjsLib.getDocument({ data: buf }).promise;
+      state.totalPages = state.pdfJsDoc.numPages;
+      state.curPage    = 1;
+      state.sigs       = [];
+      document.getElementById('empty-state').classList.add('hidden');
+      const scr = document.getElementById('pdf-scroll');
+      scr.classList.remove('hidden');
+      scr.classList.add('flex');
+      await renderPage(1);
+      toast(`PDF 已載入，共 ${state.totalPages} 頁`);
+    } catch(err) { toast('PDF 載入失敗：' + err.message, true); }
+    e.target.value = '';
+  });
+
+  // Drag-and-drop on empty area
+  const emptyEl = document.getElementById('empty-state');
+  emptyEl.addEventListener('dragover', e => { e.preventDefault(); emptyEl.classList.add('border-blue-400'); });
+  emptyEl.addEventListener('dragleave', () => emptyEl.classList.remove('border-blue-400'));
+  emptyEl.addEventListener('drop', e => {
+    e.preventDefault(); emptyEl.classList.remove('border-blue-400');
+    const f = e.dataTransfer.files[0];
+    if (f?.type === 'application/pdf') {
+      const dt = new DataTransfer(); dt.items.add(f);
+      const inp = document.getElementById('upload-pdf');
+      inp.files = dt.files;
+      inp.dispatchEvent(new Event('change'));
+    }
+  });
+
+  async function renderPage(n) {
+    const page     = await state.pdfJsDoc.getPage(n);
+    const viewport = page.getViewport({ scale: state.renderScale });
+    const cv       = document.getElementById('pdf-canvas');
+    cv.width  = viewport.width;
+    cv.height = viewport.height;
+    await page.render({ canvasContext: cv.getContext('2d'), viewport }).promise;
+    document.getElementById('page-label').textContent = `第 ${n} 頁 / 共 ${state.totalPages} 頁`;
+    document.getElementById('btn-prev').disabled = n <= 1;
+    document.getElementById('btn-next').disabled = n >= state.totalPages;
+    refreshSigElements(n);
+  }
+
+  document.getElementById('btn-prev').addEventListener('click', () => { if (state.curPage > 1) renderPage(--state.curPage); });
+  document.getElementById('btn-next').addEventListener('click', () => { if (state.curPage < state.totalPages) renderPage(++state.curPage); });
+
+  // ── Floating signature elements ──────────────────────────────────
+  function addSig(src, page, x = 80, y = 80, w = 200, h = 80) {
+    const id = ++state.sigId;
+    state.sigs.push({ id, src, x, y, w, h, page });
+    mountSigEl(state.sigs.at(-1));
+  }
+
+  function refreshSigElements(page) {
+    document.querySelectorAll('.sig-el').forEach(el => el.remove());
+    state.sigs.filter(s => s.page === page).forEach(s => mountSigEl(s));
+  }
+
+  function mountSigEl(sig) {
+    const wrap = document.getElementById('pdf-container');
+    const el   = document.createElement('div');
+    el.className  = 'sig-el';
+    el.dataset.id = sig.id;
+    el.style.cssText = `left:${sig.x}px;top:${sig.y}px;width:${sig.w}px;height:${sig.h}px;`;
+
+    const img = document.createElement('img');
+    img.src = sig.src;
+    img.style.cssText = 'width:100%;height:100%;pointer-events:none;display:block;';
+    img.draggable = false;
+    el.appendChild(img);
+
+    // Delete button
+    const del = document.createElement('div');
+    del.className = 'sig-del'; del.innerHTML = '✕';
+    del.addEventListener('click', e => { e.stopPropagation(); state.sigs = state.sigs.filter(s => s.id !== sig.id); el.remove(); });
+    el.appendChild(del);
+
+    // Resize handles
+    ['nw','ne','sw','se'].forEach(c => {
+      const h = document.createElement('div');
+      h.className = `sig-rs sig-rs-${c}`;
+      h.addEventListener('mousedown', e => startResize(e, el, sig, c));
+      el.appendChild(h);
+    });
+
+    el.addEventListener('mousedown', e => { if (e.target === el || e.target === img) startDrag(e, el, sig); });
+    el.addEventListener('touchstart', e => { if (e.target === el || e.target === img) startDragTouch(e, el, sig); }, { passive:false });
+    wrap.appendChild(el);
+  }
+
+  function startDrag(e, el, sig) {
+    e.preventDefault();
+    const ox = e.clientX - sig.x, oy = e.clientY - sig.y;
+    const mv = e => { sig.x = e.clientX - ox; sig.y = e.clientY - oy; el.style.left = sig.x+'px'; el.style.top = sig.y+'px'; };
+    const up = () => { removeEventListener('mousemove',mv); removeEventListener('mouseup',up); };
+    addEventListener('mousemove',mv); addEventListener('mouseup',up);
+  }
+  function startDragTouch(e, el, sig) {
+    e.preventDefault();
+    const t = e.touches[0], ox = t.clientX - sig.x, oy = t.clientY - sig.y;
+    const mv = e => { const t=e.touches[0]; sig.x=t.clientX-ox; sig.y=t.clientY-oy; el.style.left=sig.x+'px'; el.style.top=sig.y+'px'; };
+    const up = () => { removeEventListener('touchmove',mv); removeEventListener('touchend',up); };
+    addEventListener('touchmove',mv,{passive:false}); addEventListener('touchend',up);
+  }
+  function startResize(e, el, sig, c) {
+    e.preventDefault(); e.stopPropagation();
+    const sx=e.clientX,sy=e.clientY,ox=sig.x,oy=sig.y,ow=sig.w,oh=sig.h;
+    const mv = e => {
+      const dx=e.clientX-sx, dy=e.clientY-sy;
+      if(c==='se'){sig.w=Math.max(30,ow+dx);sig.h=Math.max(20,oh+dy);}
+      if(c==='sw'){sig.w=Math.max(30,ow-dx);sig.h=Math.max(20,oh+dy);sig.x=ox+ow-sig.w;}
+      if(c==='ne'){sig.w=Math.max(30,ow+dx);sig.h=Math.max(20,oh-dy);sig.y=oy+oh-sig.h;}
+      if(c==='nw'){sig.w=Math.max(30,ow-dx);sig.h=Math.max(20,oh-dy);sig.x=ox+ow-sig.w;sig.y=oy+oh-sig.h;}
+      el.style.left=sig.x+'px';el.style.top=sig.y+'px';el.style.width=sig.w+'px';el.style.height=sig.h+'px';
+    };
+    const up = () => { removeEventListener('mousemove',mv); removeEventListener('mouseup',up); };
+    addEventListener('mousemove',mv); addEventListener('mouseup',up);
+  }
+
+  // ── Import PNG signature ─────────────────────────────────────────
+  document.getElementById('upload-sig-img').addEventListener('change', e => {
+    const file = e.target.files[0];
+    if (!file) return;
+    if (!state.pdfJsDoc) { toast('請先載入 PDF', true); return; }
+    const rd = new FileReader();
+    rd.onload = ev => { addSig(ev.target.result, state.curPage); toast('圖片簽名已插入，可拖曳調整'); };
+    rd.readAsDataURL(file);
+    e.target.value = '';
+  });
+
+  // ── Handwriting modal open/close ─────────────────────────────────
+  document.getElementById('btn-open-pad').addEventListener('click', () => {
+    if (!state.pdfJsDoc) { toast('請先載入 PDF', true); return; }
+    clearPad(); document.getElementById('modal-pad').classList.remove('hidden');
+  });
+  document.getElementById('btn-close-pad').addEventListener('click', closePad);
+  document.getElementById('modal-pad').addEventListener('click', e => { if(e.target===e.currentTarget) closePad(); });
+  function closePad() { document.getElementById('modal-pad').classList.add('hidden'); }
+
+  // ── Pen type selection ───────────────────────────────────────────
+  document.getElementById('pen-type-group').addEventListener('click', e => {
+    const btn = e.target.closest('.pen-btn');
+    if (!btn) return;
+    document.querySelectorAll('#pen-type-group .pen-btn').forEach(b => b.classList.remove('active'));
+    btn.classList.add('active');
+    pad.penType = btn.dataset.pen;
+  });
+
+  // ── Color selection ──────────────────────────────────────────────
+  document.getElementById('color-group').addEventListener('click', e => {
+    const btn = e.target.closest('.cdot');
+    if (!btn) return;
+    document.querySelectorAll('#color-group .cdot').forEach(b => b.classList.remove('active'));
+    btn.classList.add('active');
+    pad.color = btn.dataset.color;
+  });
+
+  // ── Stroke width ─────────────────────────────────────────────────
+  document.getElementById('stroke-width').addEventListener('input', e => {
+    pad.lineWidth = +e.target.value;
+    document.getElementById('width-val').textContent = e.target.value;
+  });
+
+  // ── Canvas drawing ───────────────────────────────────────────────
+  const sigCv  = document.getElementById('sig-canvas');
+  const sigCtx = sigCv.getContext('2d');
+
+  function clearPad() {
+    sigCtx.clearRect(0,0,sigCv.width,sigCv.height);
+    pad.history=[]; pad.hasContent=false;
+    document.getElementById('pad-hint').style.opacity='1';
+  }
+  function snapshot() {
+    pad.history.push(sigCtx.getImageData(0,0,sigCv.width,sigCv.height));
+    if(pad.history.length>40) pad.history.shift();
+  }
+
+  document.getElementById('btn-clear').addEventListener('click', clearPad);
+  document.getElementById('btn-undo').addEventListener('click', () => {
+    if(!pad.history.length) return;
+    sigCtx.putImageData(pad.history.pop(),0,0);
+    if(!pad.history.length) pad.hasContent=false;
+  });
+
+  function evPos(e) {
+    const r=sigCv.getBoundingClientRect(), sx=sigCv.width/r.width, sy=sigCv.height/r.height;
+    const s=e.touches?e.touches[0]:e;
+    return { x:(s.clientX-r.left)*sx, y:(s.clientY-r.top)*sy };
+  }
+
+  // ═══════════════════════════════════════════
+  //  PEN ALGORITHMS
+  // ═══════════════════════════════════════════
+
+  /** 原子筆 – uniform width, full opacity, crisp round joins */
+  function drawBallpoint(x,y,lx,ly,color,w) {
+    sigCtx.globalAlpha=1; sigCtx.strokeStyle=color;
+    sigCtx.lineWidth=w; sigCtx.lineCap='round'; sigCtx.lineJoin='round';
+    sigCtx.beginPath(); sigCtx.moveTo(lx,ly); sigCtx.lineTo(x,y); sigCtx.stroke();
+  }
+
+  /** 鋼筆 – fast → thin; slow/turning → thick; smooth quadratic curve */
+  function drawFountain(x,y,lx,ly,color,w,vel) {
+    const t   = Math.max(0.2, Math.min(1, 1 - vel/25));
+    const dyn = w*0.4 + w*t*1.8;
+    sigCtx.globalAlpha=1; sigCtx.strokeStyle=color;
+    sigCtx.lineWidth=dyn; sigCtx.lineCap='round'; sigCtx.lineJoin='round';
+    sigCtx.beginPath(); sigCtx.moveTo(lx,ly);
+    sigCtx.quadraticCurveTo((lx+x)/2,(ly+y)/2,x,y); sigCtx.stroke();
+  }
+
+  /**
+   * 毛筆 – very wide when slow/turning, razor-thin when fast
+   *   • Main stroke with heavy velocity modulation (0.05 → 4× base width)
+   *   • Soft alpha edges (two passes: outer 40% alpha, inner 85%)
+   *   • Bristle spread: 4 thin parallel lines fan out from centre
+   *   • Ink-bleed dot at segment endpoint for 飛白 feel
+   */
+  function drawBrush(x,y,lx,ly,color,w,vel) {
+    const t      = Math.max(0.05, Math.min(1, 1 - vel/18));
+    const thick  = w*0.3 + w*t*4.5;          // 0.3w ... 4.8w
+    const angle  = Math.atan2(y-ly, x-lx) + Math.PI/2;
+
+    // Outer soft halo
+    sigCtx.globalAlpha = 0.30;
+    sigCtx.strokeStyle = color;
+    sigCtx.lineWidth   = thick*1.45;
+    sigCtx.lineCap='round'; sigCtx.lineJoin='round';
+    sigCtx.beginPath(); sigCtx.moveTo(lx,ly);
+    sigCtx.quadraticCurveTo((lx+x)/2,(ly+y)/2,x,y);
+    sigCtx.stroke();
+
+    // Core stroke
+    sigCtx.globalAlpha = 0.88;
+    sigCtx.lineWidth   = thick;
+    sigCtx.beginPath(); sigCtx.moveTo(lx,ly);
+    sigCtx.quadraticCurveTo((lx+x)/2,(ly+y)/2,x,y);
+    sigCtx.stroke();
+
+    // Bristle lines (fan spread perpendicular to stroke direction)
+    const offsets = [-0.55, -0.3, 0.3, 0.55];
+    offsets.forEach(ratio => {
+      const off = thick * ratio;
+      sigCtx.globalAlpha = Math.max(0.08, 0.25 * t);
+      sigCtx.lineWidth   = Math.max(0.4, thick*0.08);
+      sigCtx.beginPath();
+      sigCtx.moveTo(lx + Math.cos(angle)*off, ly + Math.sin(angle)*off);
+      sigCtx.lineTo(x  + Math.cos(angle)*off, y  + Math.sin(angle)*off);
+      sigCtx.stroke();
+    });
+
+    // 飛白 ink-bleed dot at end of segment when moving fast
+    if (vel > 12) {
+      sigCtx.globalAlpha = 0.10 + Math.random()*0.08;
+      sigCtx.beginPath();
+      sigCtx.arc(x, y, thick*0.4, 0, Math.PI*2);
+      sigCtx.fillStyle = color; sigCtx.fill();
+    }
+
+    sigCtx.globalAlpha = 1;
+  }
+
+  /** 鉛筆 – low alpha, grainy texture that accumulates on overlap */
+  function drawPencil(x,y,lx,ly,color,w) {
+    const dist  = Math.hypot(x-lx,y-ly) || 1;
+    const steps = Math.ceil(dist*1.5);
+    for(let i=0;i<=steps;i++){
+      const t=i/steps, px=lx+(x-lx)*t, py=ly+(y-ly)*t;
+      sigCtx.globalAlpha=0.32; sigCtx.fillStyle=color;
+      sigCtx.beginPath(); sigCtx.arc(px,py,w/2,0,Math.PI*2); sigCtx.fill();
+      if(Math.random()<0.45){
+        sigCtx.globalAlpha=0.10;
+        sigCtx.beginPath();
+        sigCtx.arc(px+(Math.random()-0.5)*w*1.8, py+(Math.random()-0.5)*w*1.8,
+                   Math.random()*w*0.35+0.3, 0, Math.PI*2);
+        sigCtx.fill();
+      }
+    }
+    sigCtx.globalAlpha=1;
+  }
+
+  /** 奇異筆 – wide, semi-transparent, square/miter edges */
+  function drawMarker(x,y,lx,ly,color,w) {
+    sigCtx.globalAlpha=0.65; sigCtx.strokeStyle=color;
+    sigCtx.lineWidth=w*3; sigCtx.lineCap='square'; sigCtx.lineJoin='miter';
+    sigCtx.beginPath(); sigCtx.moveTo(lx,ly); sigCtx.lineTo(x,y); sigCtx.stroke();
+    sigCtx.globalAlpha=1;
+  }
+
+  // ── Canvas event wiring ──────────────────────────────────────────
+  function onDown(e){
+    e.preventDefault(); snapshot();
+    pad.drawing=true; pad.hasContent=true;
+    const p=evPos(e); pad.lastX=p.x; pad.lastY=p.y; pad.lastVel=0;
+    document.getElementById('pad-hint').style.opacity='0';
+  }
+  function onMove(e){
+    if(!pad.drawing) return; e.preventDefault();
+    const p=evPos(e), vel=Math.hypot(p.x-pad.lastX,p.y-pad.lastY);
+    const {penType:pt,color:col,lineWidth:lw,lastX:lx,lastY:ly}=pad;
+    if(pt==='ballpoint') drawBallpoint(p.x,p.y,lx,ly,col,lw);
+    else if(pt==='fountain') drawFountain(p.x,p.y,lx,ly,col,lw,vel);
+    else if(pt==='brush')    drawBrush   (p.x,p.y,lx,ly,col,lw,vel);
+    else if(pt==='pencil')   drawPencil  (p.x,p.y,lx,ly,col,lw);
+    else if(pt==='marker')   drawMarker  (p.x,p.y,lx,ly,col,lw);
+    pad.lastX=p.x; pad.lastY=p.y; pad.lastVel=vel;
+  }
+  function onUp(){ pad.drawing=false; }
+
+  sigCv.addEventListener('mousedown',  onDown);
+  sigCv.addEventListener('mousemove',  onMove);
+  sigCv.addEventListener('mouseup',    onUp);
+  sigCv.addEventListener('mouseleave', onUp);
+  sigCv.addEventListener('touchstart', onDown, {passive:false});
+  sigCv.addEventListener('touchmove',  onMove, {passive:false});
+  sigCv.addEventListener('touchend',   onUp);
+
+  // ── Apply handwritten signature ──────────────────────────────────
+  document.getElementById('btn-apply').addEventListener('click', () => {
+    if(!pad.hasContent){ toast('請先在簽名板書寫',true); return; }
+    const imgData=sigCtx.getImageData(0,0,sigCv.width,sigCv.height);
+    const b=contentBounds(imgData);
+    if(!b){ toast('簽名板是空的',true); return; }
+    const pad2=8;
+    const cx=Math.max(0,b.x1-pad2), cy=Math.max(0,b.y1-pad2);
+    const cw=Math.min(sigCv.width, b.x2+pad2)-cx;
+    const ch=Math.min(sigCv.height,b.y2+pad2)-cy;
+    const tmp=document.createElement('canvas'); tmp.width=cw; tmp.height=ch;
+    tmp.getContext('2d').drawImage(sigCv,cx,cy,cw,ch,0,0,cw,ch);
+    const dispW=Math.min(cw,280), dispH=Math.round(ch/cw*dispW);
+    addSig(tmp.toDataURL('image/png'), state.curPage, 100, 100, dispW, dispH);
+    closePad(); clearPad();
+    toast('簽名已插入，可拖曳調整位置與大小');
+  });
+
+  function contentBounds(imgData){
+    const {data,width,height}=imgData;
+    let x1=width,y1=height,x2=0,y2=0,found=false;
+    for(let y=0;y<height;y++) for(let x=0;x<width;x++)
+      if(data[(y*width+x)*4+3]>8){
+        if(x<x1)x1=x; if(x>x2)x2=x; if(y<y1)y1=y; if(y>y2)y2=y; found=true;
+      }
+    return found?{x1,y1,x2,y2}:null;
+  }
+
+  // ── Export PDF ───────────────────────────────────────────────────
+  document.getElementById('btn-export').addEventListener('click', async () => {
+    if(!state.rawBytes)    { toast('請先載入 PDF',true); return; }
+    if(!state.sigs.length) { toast('尚未加入任何簽名',true); return; }
+    toast('正在產生 PDF…');
+    try {
+      const {PDFDocument}=PDFLib;
+      const doc=await PDFDocument.load(state.rawBytes);
+      for(const sig of state.sigs){
+        const page=doc.getPage(sig.page-1);
+        const {width:pW,height:pH}=page.getSize();
+        const pdfJsPage=await state.pdfJsDoc.getPage(sig.page);
+        const vp=pdfJsPage.getViewport({scale:state.renderScale});
+        const scX=pW/vp.width, scY=pH/vp.height;
+        const raw=sig.src.split(',')[1];
+        const bytes=Uint8Array.from(atob(raw),c=>c.charCodeAt(0));
+        const emb=sig.src.startsWith('data:image/png')
+                  ? await doc.embedPng(bytes)
+                  : await doc.embedJpg(bytes);
+        page.drawImage(emb,{
+          x:sig.x*scX, y:pH-(sig.y+sig.h)*scY,
+          width:sig.w*scX, height:sig.h*scY,
+        });
+      }
+      const out=await doc.save();
+      const url=URL.createObjectURL(new Blob([out],{type:'application/pdf'}));
+      Object.assign(document.createElement('a'),{href:url,download:`簽名_${state.origName}.pdf`}).click();
+      URL.revokeObjectURL(url);
+      toast('PDF 匯出成功 ✓');
+    } catch(err){ toast('匯出失敗：'+err.message,true); console.error(err); }
+  });
+
+  // ── Toast ────────────────────────────────────────────────────────
+  let toastTm;
+  function toast(msg, isErr=false){
+    const el=document.getElementById('toast');
+    el.textContent=msg;
+    el.className=`fixed bottom-6 right-6 text-white text-sm px-5 py-3
+                  rounded-xl shadow-xl z-50 ${isErr?'bg-red-600':'bg-slate-800'}`;
+    clearTimeout(toastTm);
+    toastTm=setTimeout(()=>el.classList.add('hidden'),3200);
+  }
+  </script>
+</body>
+</html>
