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+<!DOCTYPE html>
+<html lang="en">
+<head>
+<meta charset="UTF-8">
+<meta name="viewport" content="width=device-width, initial-scale=1.0">
+<title>Deck Preview — markdown in, slides out, nothing leaves your browser</title>
+<style>
+  :root {
+    --bg: #0f1115;
+    --panel: #171a21;
+    --panel-2: #1e222b;
+    --ink: #e8eaf0;
+    --ink-dim: #9aa1af;
+    --accent: #6ea8fe;
+    --accent-2: #9d7bff;
+    --line: #2a2f3a;
+    --radius: 12px;
+  }
+  * { box-sizing: border-box; }
+  html, body { height: 100%; }
+  body {
+    margin: 0;
+    font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
+    background: var(--bg);
+    color: var(--ink);
+    display: flex;
+    flex-direction: column;
+    min-height: 100vh;
+  }
+  header {
+    padding: 18px 20px 10px;
+  }
+  header h1 {
+    margin: 0;
+    font-size: 1.35rem;
+    letter-spacing: 0.2px;
+  }
+  header h1 .dot { color: var(--accent); }
+  header p {
+    margin: 6px 0 0;
+    color: var(--ink-dim);
+    font-size: 0.9rem;
+    max-width: 62ch;
+  }
+  main {
+    flex: 1;
+    display: grid;
+    grid-template-columns: minmax(280px, 420px) 1fr;
+    gap: 14px;
+    padding: 12px 20px 16px;
+    min-height: 0;
+  }
+  .editor-pane {
+    display: flex;
+    flex-direction: column;
+    min-height: 0;
+  }
+  .editor-pane label {
+    font-size: 0.78rem;
+    text-transform: uppercase;
+    letter-spacing: 0.08em;
+    color: var(--ink-dim);
+    margin-bottom: 6px;
+  }
+  textarea {
+    flex: 1;
+    min-height: 220px;
+    resize: none;
+    background: var(--panel);
+    color: var(--ink);
+    border: 1px solid var(--line);
+    border-radius: var(--radius);
+    padding: 14px;
+    font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
+    font-size: 0.9rem;
+    line-height: 1.55;
+    outline: none;
+  }
+  textarea:focus { border-color: var(--accent); }
+  .hint {
+    margin-top: 8px;
+    font-size: 0.78rem;
+    color: var(--ink-dim);
+    line-height: 1.5;
+  }
+  .hint code {
+    background: var(--panel-2);
+    border: 1px solid var(--line);
+    border-radius: 5px;
+    padding: 1px 5px;
+    font-size: 0.75rem;
+  }
+  .stage {
+    display: flex;
+    flex-direction: column;
+    min-height: 0;
+  }
+  .toolbar {
+    display: flex;
+    align-items: center;
+    gap: 8px;
+    margin-bottom: 10px;
+    flex-wrap: wrap;
+  }
+  button {
+    background: var(--panel-2);
+    color: var(--ink);
+    border: 1px solid var(--line);
+    border-radius: 9px;
+    padding: 8px 14px;
+    font-size: 0.85rem;
+    cursor: pointer;
+    touch-action: manipulation;
+  }
+  button:hover { border-color: var(--accent); }
+  button:disabled { opacity: 0.4; cursor: default; }
+  button.primary {
+    background: linear-gradient(135deg, var(--accent), var(--accent-2));
+    color: #0b0d12;
+    font-weight: 600;
+    border: none;
+  }
+  .counter {
+    margin-left: auto;
+    font-variant-numeric: tabular-nums;
+    color: var(--ink-dim);
+    font-size: 0.85rem;
+  }
+  .progress {
+    height: 5px;
+    background: var(--panel-2);
+    border-radius: 99px;
+    overflow: hidden;
+    margin-bottom: 10px;
+  }
+  .progress > div {
+    height: 100%;
+    width: 0;
+    background: linear-gradient(90deg, var(--accent), var(--accent-2));
+    transition: width 180ms ease;
+  }
+  .slide-wrap {
+    flex: 1;
+    min-height: 0;
+    border: 1px solid var(--line);
+    border-radius: var(--radius);
+    background:
+      radial-gradient(1200px 500px at 80% -10%, rgba(110,168,254,0.10), transparent),
+      radial-gradient(900px 500px at 0% 110%, rgba(157,123,255,0.10), transparent),
+      var(--panel);
+    overflow-y: auto;
+    touch-action: pan-y;
+  }
+  .slide {
+    padding: clamp(22px, 5vw, 56px);
+    min-height: 100%;
+    display: flex;
+    flex-direction: column;
+    justify-content: center;
+  }
+  .slide h1 {
+    font-size: clamp(1.6rem, 4.5vw, 3rem);
+    margin: 0 0 0.5em;
+    line-height: 1.15;
+  }
+  .slide h2 {
+    font-size: clamp(1.2rem, 3vw, 1.9rem);
+    margin: 0 0 0.6em;
+    color: var(--ink-dim);
+    font-weight: 500;
+  }
+  .slide ul {
+    margin: 0;
+    padding-left: 1.3em;
+    font-size: clamp(1rem, 2.2vw, 1.35rem);
+    line-height: 1.7;
+  }
+  .slide p {
+    font-size: clamp(1rem, 2.2vw, 1.35rem);
+    line-height: 1.7;
+    margin: 0.3em 0;
+  }
+  .slide .empty { color: var(--ink-dim); font-style: italic; }
+  .slide code, .export-note code {
+    background: rgba(110,168,254,0.12);
+    border-radius: 5px;
+    padding: 1px 6px;
+    font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
+    font-size: 0.9em;
+  }
+  .export-note {
+    font-size: 0.78rem;
+    color: var(--ink-dim);
+    margin-top: 8px;
+  }
+  footer {
+    padding: 10px 20px 16px;
+    font-size: 0.8rem;
+    color: var(--ink-dim);
+  }
+  footer a { color: var(--accent); text-decoration: none; }
+  footer a:hover { text-decoration: underline; }
+  @media (max-width: 820px) {
+    main {
+      grid-template-columns: 1fr;
+      grid-template-rows: auto 1fr;
+    }
+    textarea { min-height: 150px; flex: none; }
+    .slide-wrap { min-height: 300px; }
+  }
+</style>
+</head>
+<body>
+<header>
+  <h1>Deck Preview<span class="dot">.</span></h1>
+  <p>Type markdown-ish slides on the left, watch them render live on the right.
+     Navigate with arrow keys or swipe. Everything runs in your browser — nothing is saved or sent anywhere.</p>
+</header>
+<main>
+  <section class="editor-pane">
+    <label for="src">Slides</label>
+    <textarea id="src" spellcheck="false"></textarea>
+    <p class="hint">
+      <code># Title</code> heading · <code>## Subtitle</code> · <code>- bullet</code> point ·
+      <code>---</code> on its own line starts a new slide · inline <code>**bold**</code>, <code>*italic*</code>, <code>`code`</code>.
+      Plain lines become paragraphs.
+    </p>
+  </section>
+  <section class="stage">
+    <div class="toolbar">
+      <button id="prev" aria-label="Previous slide">&larr; Prev</button>
+      <button id="next" aria-label="Next slide">Next &rarr;</button>
+      <button id="copy" class="primary">Copy deck as HTML</button>
+      <span class="counter" id="counter">1 / 1</span>
+    </div>
+    <div class="progress" role="progressbar" aria-label="Deck progress"><div id="bar"></div></div>
+    <div class="slide-wrap" id="wrap"><article class="slide" id="slide"></article></div>
+    <p class="export-note">The copied file is a self-contained deck: open it in any browser and use &larr; / &rarr; to present.</p>
+  </section>
+</main>
+<footer>built by the <a href="https://github.com/teahubxyz/time">Time venture loop</a></footer>
+<script>
+(function () {
+  "use strict";
+  var src = document.getElementById("src");
+  var slideEl = document.getElementById("slide");
+  var counterEl = document.getElementById("counter");
+  var barEl = document.getElementById("bar");
+  var wrap = document.getElementById("wrap");
+  var prevBtn = document.getElementById("prev");
+  var nextBtn = document.getElementById("next");
+  var copyBtn = document.getElementById("copy");
+
+  var SAMPLE = [
+    "# Deck Preview",
+    "## Markdown in, slides out",
+    "",
+    "- Type on the left, slides render live",
+    "- Navigate with arrow keys or swipe",
+    "- Nothing is saved or sent anywhere",
+    "",
+    "---",
+    "# A simple syntax",
+    "",
+    "- `#` and `##` for titles and subtitles",
+    "- `-` or `*` for bullet points",
+    "- `---` on its own line starts a new slide",
+    "- Inline **bold**, *italic* and `code`",
+    "",
+    "---",
+    "# Take it with you",
+    "",
+    "Press *Copy deck as HTML* and you get one self-contained file.",
+    "Open it in any browser and present with the arrow keys.",
+    "",
+    "---",
+    "# That's it",
+    "",
+    "- No accounts",
+    "- No servers",
+    "- Just your words, as slides"
+  ].join("\n");
+
+  function esc(s) {
+    return s.replace(/&/g, "&amp;").replace(/</g, "&lt;").replace(/>/g, "&gt;");
+  }
+
+  function inline(s) {
+    var out = esc(s);
+    out = out.replace(/\*\*([^*]+)\*\*/g, "<strong>$1</strong>");
+    out = out.replace(/\*([^*]+)\*/g, "<em>$1</em>");
+    out = out.replace(/`([^`]+)`/g, "<code>$1</code>");
+    return out;
+  }
+
+  // Split raw text into slides on lines that are only "---".
+  function splitSlides(text) {
+    var lines = text.split(/\r?\n/);
+    var slides = [[]];
+    for (var i = 0; i < lines.length; i++) {
+      if (/^\s*---+\s*$/.test(lines[i])) {
+        slides.push([]);
+      } else {
+        slides[slides.length - 1].push(lines[i]);
+      }
+    }
+    return slides;
+  }
+
+  // Render one slide's lines to HTML.
+  function renderSlide(lines) {
+    var html = "";
+    var inList = false;
+    var hasContent = false;
+    for (var i = 0; i < lines.length; i++) {
+      var line = lines[i];
+      var t = line.trim();
+      if (t === "") {
+        if (inList) { html += "</ul>"; inList = false; }
+        continue;
+      }
+      hasContent = true;
+      if (t.indexOf("# ") === 0) {
+        if (inList) { html += "</ul>"; inList = false; }
+        html += "<h1>" + inline(t.slice(2)) + "</h1>";
+      } else if (t.indexOf("## ") === 0) {
+        if (inList) { html += "</ul>"; inList = false; }
+        html += "<h2>" + inline(t.slice(3)) + "</h2>";
+      } else if (t.indexOf("- ") === 0 || t.indexOf("* ") === 0) {
+        if (!inList) { html += "<ul>"; inList = true; }
+        html += "<li>" + inline(t.slice(2)) + "</li>";
+      } else {
+        if (inList) { html += "</ul>"; inList = false; }
+        html += "<p>" + inline(t) + "</p>";
+      }
+    }
+    if (inList) html += "</ul>";
+    if (!hasContent) html = '<p class="empty">(empty slide)</p>';
+    return html;
+  }
+
+  var slides = [];
+  var current = 0;
+
+  function parse() {
+    slides = splitSlides(src.value);
+    if (slides.length === 0) slides = [[]];
+    if (current >= slides.length) current = slides.length - 1;
+    if (current < 0) current = 0;
+    render();
+  }
+
+  function render() {
+    slideEl.innerHTML = renderSlide(slides[current]);
+    counterEl.textContent = (current + 1) + " / " + slides.length;
+    var pct = slides.length <= 1 ? 100 : (current / (slides.length - 1)) * 100;
+    barEl.style.width = pct + "%";
+    prevBtn.disabled = current === 0;
+    nextBtn.disabled = current === slides.length - 1;
+  }
+
+  function go(delta) {
+    var next = current + delta;
+    if (next < 0 || next > slides.length - 1) return;
+    current = next;
+    render();
+  }
+
+  src.addEventListener("input", parse);
+  prevBtn.addEventListener("click", function () { go(-1); });
+  nextBtn.addEventListener("click", function () { go(1); });
+
+  document.addEventListener("keydown", function (e) {
+    if (e.target === src) return; // don't steal keys while typing
+    if (e.key === "ArrowRight" || e.key === "PageDown" || e.key === " ") { e.preventDefault(); go(1); }
+    else if (e.key === "ArrowLeft" || e.key === "PageUp") { e.preventDefault(); go(-1); }
+    else if (e.key === "Home") { current = 0; render(); }
+    else if (e.key === "End") { current = slides.length - 1; render(); }
+  });
+
+  // Swipe navigation.
+  var touchX = null;
+  wrap.addEventListener("touchstart", function (e) { touchX = e.touches[0].clientX; }, { passive: true });
+  wrap.addEventListener("touchend", function (e) {
+    if (touchX === null) return;
+    var dx = e.changedTouches[0].clientX - touchX;
+    if (Math.abs(dx) > 40) go(dx < 0 ? 1 : -1);
+    touchX = null;
+  }, { passive: true });
+
+  // Build the self-contained export deck.
+  function buildExport() {
+    var slidesHtml = slides.map(function (s) {
+      return '<section class="s">' + renderSlide(s) + "</section>";
+    }).join("\n");
+    return "<!DOCTYPE html>\n<html lang=\"en\">\n<head>\n<meta charset=\"UTF-8\">\n" +
+      "<meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\">\n" +
+      "<title>Deck</title>\n<style>\n" +
+      "*{box-sizing:border-box}html,body{height:100%;margin:0}" +
+      "body{font-family:ui-sans-serif,system-ui,-apple-system,'Segoe UI',Roboto,sans-serif;background:#0f1115;color:#e8eaf0;display:flex;flex-direction:column}" +
+      ".bar{height:5px;background:#1e222b}.bar>div{height:100%;width:0;background:linear-gradient(90deg,#6ea8fe,#9d7bff);transition:width .18s ease}" +
+      "main{flex:1;overflow-y:auto}" +
+      ".s{display:none;padding:clamp(24px,6vw,64px);min-height:100%;flex-direction:column;justify-content:center}" +
+      ".s.on{display:flex}" +
+      "h1{font-size:clamp(1.8rem,5vw,3.2rem);margin:0 0 .5em;line-height:1.15}" +
+      "h2{font-size:clamp(1.2rem,3vw,1.9rem);color:#9aa1af;font-weight:500;margin:0 0 .6em}" +
+      "ul{margin:0;padding-left:1.3em;font-size:clamp(1.1rem,2.5vw,1.5rem);line-height:1.7}" +
+      "p{font-size:clamp(1.1rem,2.5vw,1.5rem);line-height:1.7;margin:.3em 0}" +
+      "code{background:rgba(110,168,254,.12);border-radius:5px;padding:1px 6px;font-family:ui-monospace,Menlo,Consolas,monospace;font-size:.9em}" +
+      ".empty{color:#9aa1af;font-style:italic}" +
+      ".n{position:fixed;bottom:12px;right:16px;color:#9aa1af;font-size:.85rem;font-variant-numeric:tabular-nums}" +
+      "\n</style>\n</head>\n<body>\n<div class=\"bar\"><div id=\"b\"></div></div>\n<main>\n" +
+      slidesHtml +
+      "\n</main>\n<div class=\"n\" id=\"n\"></div>\n<script>\n" +
+      "var s=document.querySelectorAll('.s'),i=0,n=document.getElementById('n'),b=document.getElementById('b');\n" +
+      "function show(){for(var k=0;k<s.length;k++)s[k].classList.toggle('on',k===i);n.textContent=(i+1)+' / '+s.length;b.style.width=(s.length<=1?100:i/(s.length-1)*100)+'%';}\n" +
+      "function go(d){var j=i+d;if(j<0||j>s.length-1)return;i=j;show();}\n" +
+      "document.addEventListener('keydown',function(e){if(e.key==='ArrowRight'||e.key===' '||e.key==='PageDown'){e.preventDefault();go(1);}else if(e.key==='ArrowLeft'||e.key==='PageUp'){e.preventDefault();go(-1);}else if(e.key==='Home'){i=0;show();}else if(e.key==='End'){i=s.length-1;show();}});\n" +
+      "var x=null;document.addEventListener('touchstart',function(e){x=e.touches[0].clientX;},{passive:true});" +
+      "document.addEventListener('touchend',function(e){if(x===null)return;var d=e.changedTouches[0].clientX-x;if(Math.abs(d)>40)go(d<0?1:-1);x=null;},{passive:true});\n" +
+      "show();\n<\/script>\n</body>\n</html>";
+  }
+
+  copyBtn.addEventListener("click", function () {
+    var html = buildExport();
+    var done = function () {
+      var old = copyBtn.textContent;
+      copyBtn.textContent = "Copied!";
+      setTimeout(function () { copyBtn.textContent = old; }, 1500);
+    };
+    if (navigator.clipboard && navigator.clipboard.writeText) {
+      navigator.clipboard.writeText(html).then(done, function () { fallbackCopy(html, done); });
+    } else {
+      fallbackCopy(html, done);
+    }
+  });
+
+  function fallbackCopy(text, done) {
+    var ta = document.createElement("textarea");
+    ta.value = text;
+    ta.style.position = "fixed";
+    ta.style.opacity = "0";
+    document.body.appendChild(ta);
+    ta.select();
+    try { document.execCommand("copy"); done(); } catch (e) { /* give up quietly */ }
+    document.body.removeChild(ta);
+  }
+
+  src.value = SAMPLE;
+  parse();
+})();
+</script>
+</body>
+</html>