diff --git a/trending.py b/trending.py
new file mode 100644
index 0000000..7a55db1
--- /dev/null
+++ b/trending.py
@@ -0,0 +1,139 @@
+#!/usr/bin/env python3
+import argparse, datetime as dt, html, json, pathlib, re, urllib.parse, urllib.request
+from html import unescape
+
+ROOT = pathlib.Path(__file__).resolve().parent
+PERIODS = [("daily","today"),("weekly","this week"),("monthly","this month")]
+
+def fetch(period):
+    url = "https://github.com/trending?" + urllib.parse.urlencode({"since": period})
+    req = urllib.request.Request(url, headers={
+        "User-Agent": "notplanned-trending/0.1",
+        "Accept": "text/html,application/xhtml+xml",
+    })
+    with urllib.request.urlopen(req, timeout=20) as r:
+        return r.read().decode("utf-8", "replace")
+
+def clean(fragment):
+    fragment = re.sub(r"<[^>]+>", " ", fragment)
+    return " ".join(unescape(fragment).split())
+
+def parse(period, body):
+    articles = re.findall(r'<article[^>]+class="[^"]*Box-row[^"]*"[^>]*>(.*?)</article>', body, re.S|re.I)
+    rows = []
+    period_phrase = dict(PERIODS)[period]
+    for rank, article in enumerate(articles, 1):
+        m = re.search(r'<h2[^>]*>.*?<a[^>]+href="/([^"#?]+/[^"#?]+)"', article, re.S|re.I)
+        if not m:
+            continue
+        repo = unescape(m.group(1)).strip()
+        if repo.count("/") != 1:
+            continue
+        desc = ""
+        pm = re.search(r'<p[^>]+class="[^"]*color-fg-muted[^"]*"[^>]*>(.*?)</p>', article, re.S|re.I)
+        if pm:
+            desc = clean(pm.group(1))
+        lang = ""
+        lm = re.search(r'itemprop="programmingLanguage"[^>]*>(.*?)</span>', article, re.S|re.I)
+        if lm:
+            lang = clean(lm.group(1))
+        stars = None
+        sm = re.search(r'([0-9][0-9,]*)\s+stars\s+' + re.escape(period_phrase), clean(article), re.I)
+        if sm:
+            stars = int(sm.group(1).replace(",",""))
+        rows.append({
+            "repo": repo,
+            "url": f"https://github.com/{repo}",
+            "rank": rank,
+            "description": desc,
+            "language": lang,
+            "stars_gained": stars,
+        })
+    return rows
+
+def build():
+    now = dt.datetime.now(dt.timezone.utc).isoformat()
+    periods = {}
+    for period, _ in PERIODS:
+        periods[period] = parse(period, fetch(period))
+
+    merged = {}
+    for period, rows in periods.items():
+        for row in rows:
+            x = merged.setdefault(row["repo"], {
+                "repo": row["repo"],
+                "url": row["url"],
+                "description": row["description"],
+                "language": row["language"],
+                "daily_rank": None, "weekly_rank": None, "monthly_rank": None,
+                "daily_stars": None, "weekly_stars": None, "monthly_stars": None,
+            })
+            x[f"{period}_rank"] = row["rank"]
+            x[f"{period}_stars"] = row["stars_gained"]
+            if not x["description"] and row["description"]:
+                x["description"] = row["description"]
+            if not x["language"] and row["language"]:
+                x["language"] = row["language"]
+
+    for x in merged.values():
+        x["periods"] = sum(x[f"{p}_rank"] is not None for p, _ in PERIODS)
+        # Mechanical prominence only: preserve GitHub rank, favor appearing in more windows.
+        x["prominence"] = sum(
+            (26 - min(x[f"{p}_rank"], 25)) * w
+            for p, w in [("daily",3),("weekly",2),("monthly",1)]
+            if x[f"{p}_rank"] is not None
+        )
+
+    items = sorted(merged.values(), key=lambda x: (
+        -x["periods"],
+        x["daily_rank"] if x["daily_rank"] is not None else 999,
+        x["weekly_rank"] if x["weekly_rank"] is not None else 999,
+        x["monthly_rank"] if x["monthly_rank"] is not None else 999,
+        x["repo"].lower(),
+    ))
+    return {"generated_at": now, "source":"https://github.com/trending", "periods": periods, "merged": items}
+
+def card(x):
+    def badge(label, rank, stars):
+        if rank is None: return ""
+        gain = f" · +{stars:,}" if stars is not None else ""
+        return f'<span class="badge">{label} #{rank}{gain}</span>'
+    badges = "".join([
+        badge("day", x["daily_rank"], x["daily_stars"]),
+        badge("week", x["weekly_rank"], x["weekly_stars"]),
+        badge("month", x["monthly_rank"], x["monthly_stars"]),
+    ])
+    desc = html.escape(x["description"])
+    lang = html.escape(x["language"] or "—")
+    repo = html.escape(x["repo"])
+    url = html.escape(x["url"], quote=True)
+    return f"""<a class="repo-card" href="{url}" target="_blank" rel="noreferrer">
+      <div class="repo-top"><h3>{repo}</h3><span class="period-count">{x['periods']}/3</span></div>
+      <p>{desc}</p>
+      <div class="badges">{badges}</div>
+      <div class="lang">{lang}</div>
+    </a>"""
+
+def render(out_html, out_json):
+    data = build()
+    tpl = (ROOT/"trending-template.html").read_text()
+    counts = {p: len(data["periods"][p]) for p, _ in PERIODS}
+    overlap = sum(1 for x in data["merged"] if x["periods"] >= 2)
+    page = (tpl
+      .replace("__UPDATED__", data["generated_at"][:16].replace("T"," "))
+      .replace("__DAILY__", str(counts["daily"]))
+      .replace("__WEEKLY__", str(counts["weekly"]))
+      .replace("__MONTHLY__", str(counts["monthly"]))
+      .replace("__OVERLAP__", str(overlap))
+      .replace("__CARDS__", "\n".join(card(x) for x in data["merged"]))
+    )
+    pathlib.Path(out_html).write_text(page)
+    pathlib.Path(out_json).write_text(json.dumps(data, indent=2)+"\n")
+    print(json.dumps({"daily":counts["daily"],"weekly":counts["weekly"],"monthly":counts["monthly"],"merged":len(data["merged"]),"overlap":overlap}))
+
+if __name__ == "__main__":
+    p=argparse.ArgumentParser()
+    p.add_argument("--html-out", required=True)
+    p.add_argument("--json-out", required=True)
+    a=p.parse_args()
+    render(a.html_out,a.json_out)