User Prompt
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Please help me build a single HTML file app.
Everything, including JavaScript and CSS, should be inlined into the one HTML file, and ideally it should have no font or script dependencies. Please style the app to be bright and plain.
The app should be a clone of the board game Guess Who?, but with emojis instead of people. The name of the app is "Guess the emoji!".
The game is played by two players, but the app shows the perspective of one player only. When playing this game, the players might be sitting with one phone or iPad each.
The game is meant to be played in landscape mode, but it's ok if it works in portrait mode, as well.
The game should show a grid of cards with 8 columns and 3 rows. Below these 3 rows, there is a fourth row with 1 centered card.
A “card”, possibly constructed as a single div with rounded corners, should show a centered emoji.
If a card is clicked or touched, it should flip with a flip animation. If it is touched again, it should flip back. The back of the card should have a color that I can later change in the CSS.
In the lower right corner, there is a cogwheel which, when clicked, brings up a settings dialog. The settings are:
* “Random seed”, which is a string that by default is set to the current date.
* A list of checkboxes for which groups of emojis to include. This list includes: Smileys & Emotion, People & Body, Animals & Nature, Food & Drink, Travel & Places, Activities, Objects, Symbols, and Flags. People & Body, Animals & Nature, and Food & Drink are checked by default.
To the right of the cogwheel, there is a “?” button. Clicking this brings up an info dialog with some placeholder text that we will fill in later.
When the app is started, a random selection of emojis is made for the 8 × 3 = 24 cards, from the emoji groups selected for inclusion. The random selection should be stable using the random seed, which will likely require some custom JavaScript.
Finally, out of the picked 24 emojis, one is randomly selected, not using the random seed, to be the emoji for the single card in the fourth row.
Just to the right of the card in the fourth row, there is a button with a 🔄. When this is clicked, a new card is randomly picked from the 24 emojis.
ChatGPT 5.2 response
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```html
Guess the emoji!
Guess the emoji!
Flip cards to eliminate. Your secret emoji is shown below.
Settings
This seed controls which 24 emojis are picked for the 8 × 3 grid. Same seed + same emoji groups gives the same grid.
Emoji groups to include
The secret emoji is picked from the 24 grid emojis, but it does not use the seed.