Build a single-page web app called "Capital Call Calendar" for a family office next-generation member preparing for a family meeting. Deliver one self-contained HTML file (HTML, CSS and vanilla JavaScript). Use no libraries, no CDN links, no fonts from the web and no network requests of any kind: everything must run in the browser on this one computer, even with Wi-Fi off. It must read well on a projector.

INPUT
- A button to open a CSV file, plus a "Load sample data" button that uses the sample rows pasted below (embed them in the file).
- Columns: Fund, Strategy, Status (Confirmed or Estimate), Notice date, Due date, Amount, Source, Notes. Some cells may be blank.
- Never send the data anywhere. Show a small note: "Your file stays on this computer. Nothing is uploaded."

WHAT TO SHOW
1. A 12-month calendar starting with the earliest due month: one column per month showing total calls due, split into a solid bar for confirmed notices and a hatched, lighter bar for estimates. Label the hatched part "Estimate" so nobody reads it as a known amount.
2. Under each month, list the calls: fund, amount, and a "Confirmed" or "Estimate" tag.
3. An alert threshold slider, $500K to $5M in $250K steps (default $2M). Any month whose total is above it turns orange and gets a flag that says how much of that month is confirmed versus estimated.
4. A "Needs attention" panel listing every row with missing information: no due date, no amount, or a confirmed notice without a notice date. Rows without a due date go in an "Unscheduled" box instead of the calendar. Rows without an amount appear in their month with "Amount missing" and count as $0.
5. Four headline tiles: confirmed calls (total and count), estimated calls (total and count), the highest month and its total, and the number of rows that need attention.
6. A table by fund: confirmed, estimated, and next due date.
7. A footer: "Fictional data. Estimates are planning guesses, not forecasts. Not investment advice."

LOOK
White background, navy text, blue for confirmed, light blue hatching for estimates, orange only for alerts and missing information. A classic serif for headings and a clean sans-serif for everything else. Dense and useful rather than decorative.

CHECK YOUR WORK
With the sample data: 17 rows across 6 funds. Confirmed calls total $3.9M across 5 notices. Estimates total $8.8M across 12 rows. The highest month is March 2027 at $4.5M, all of it estimates, and at the default $2M threshold it is the only month flagged. Two rows need attention: Tidewell's confirmed notice has no due date ($750K, unscheduled) and Brambleton's August 2027 estimate has no amount. If anything differs, fix it before you finish.

SAMPLE DATA
Fund,Strategy,Status,Notice date,Due date,Amount,Source,Notes
Quillfield Buyout Fund III,Buyout,Confirmed,2026-10-20,2026-11-10,1250000,Capital call notice,
Larkspur Growth Partners IV,Growth equity,Confirmed,2026-10-28,2026-11-18,600000,Capital call notice,
Oakmere Real Estate Partners II,Real estate,Confirmed,2026-11-02,2026-12-01,900000,Capital call notice,
Tidewell Infrastructure Fund I,Infrastructure,Confirmed,2026-11-01,,750000,Capital call notice,Due date not stated on notice
Brambleton Ventures VII,Venture,Confirmed,2026-10-30,2026-12-08,400000,Capital call notice,
Quillfield Buyout Fund III,Buyout,Estimate,,2027-01-15,1000000,Manager pacing guidance,
Kestrel Point Credit Fund II,Private credit,Estimate,,2027-01-20,500000,Family office estimate,
Larkspur Growth Partners IV,Growth equity,Estimate,,2027-02-15,600000,Manager pacing guidance,
Quillfield Buyout Fund III,Buyout,Estimate,,2027-03-10,1500000,Manager pacing guidance,Expected add-on acquisition
Oakmere Real Estate Partners II,Real estate,Estimate,,2027-03-15,1200000,Manager pacing guidance,
Tidewell Infrastructure Fund I,Infrastructure,Estimate,,2027-03-22,1000000,Family office estimate,
Kestrel Point Credit Fund II,Private credit,Estimate,,2027-03-31,800000,Family office estimate,
Brambleton Ventures VII,Venture,Estimate,,2027-04-12,400000,Family office estimate,
Oakmere Real Estate Partners II,Real estate,Estimate,,2027-06-15,700000,Manager pacing guidance,
Larkspur Growth Partners IV,Growth equity,Estimate,,2027-07-15,500000,Family office estimate,
Brambleton Ventures VII,Venture,Estimate,,2027-08-16,,Family office estimate,Amount not yet estimated
Tidewell Infrastructure Fund I,Infrastructure,Estimate,,2027-10-15,600000,Family office estimate,