Double-Date Mega Sale

Double-Date Mega Sale is a landing page for a single-day shopping event — 11.11, Black Friday, an anniversary sale. It is loud on purpose, but the trust work is what makes it convert: published stock counts, a stated rule that prices only go up through the day, and a promise that the "was" prices were not inflated first.
Sections, in order

Sticky navbar with anchors and a reminder button.
Hero — an oversized date headline in gradient display type, a countdown to the sale opening, two calls to action and the early-access explanation.
Gradient marquee repeating the four commercial promises.
Vouchers — three dashed coupon cards with click-to-copy codes and their stacking rules written on the card.
Flash slots — a working four-tab switcher for the day's time slots, each with a product grid: photo, discount flag, now and was prices, and a stock progress bar with the units claimed. Later slots show "opens at" instead of a fake bar.
Spend and save ladder — four rungs applied automatically after vouchers, with the middle one highlighted.
What happens after you press pay — three cards on dispatch, returns that include sale items, and the price-history promise.
Sale rules FAQ — six questions: stacking, early access, selling out mid-checkout, whether prices drop later, delivery speed, returns.
Reminder list — a short form promising exactly two messages.
Sticky bottom bar that appears past the hero and mirrors the live countdown.

Design and style. Crimson and amber on near-black, Anton display type for the headlines with Inter for everything readable, gradient buttons, dashed coupon edges and glowing hover states. Countdown (mirrored into the sticky bar), copy-to-clipboard with an older-browser fallback, slot tabs, FAQ accordion, scroll reveal and mobile menu are all vanilla JavaScript.
Before you publish. Set the sale start in the countdown script — it feeds the hero and the sticky bar from one value, so there is only one date to change. Then edit the four slot panels: prices, discount flags and the stock bar widths, keeping each bar's width in step with the percentage written under it, since a bar that disagrees with its own caption reads as decoration. The voucher codes must exist in your shop before this page goes live; a copied code that fails at checkout costs the order and the customer. The reminder form uses named inputs with no action attribute, so PageHub attaches the handler on publish and sign-ups arrive in Form Submissions.
Best suited to 11.11 and 12.12 sales, Black Friday, anniversary and clearance events, app-wide promotions, and any shop whose whole month depends on one day of trading.