Kalkulator Pro

Cinevva's analyzer read this game's design doc and its source, then wrote the brief below. "Make your own" hands it to the game creator as your opening message, so you start from a real spec rather than a one-line idea.

Create a responsive single-screen Indonesian calculator web app titled “Kalkulator Pro”. It is an interactive utility rather than an action game: the goal is to enter arithmetic, calculate results, optionally use scientific and memory functions, and review prior calculations.

Visual presentation: center a compact calculator card on the page, about 410px wide at most, with rounded 30px corners, translucent dark navy/indigo glass styling, a thin light border, inset highlight, blur, and a strong soft shadow. The full viewport background is nearly black/navy with a subtle 28px square grid overlay plus purple glow in the upper-left and cyan glow in the lower-right. Use a clean modern system/Inter-like sans-serif font. The card header has a gradient rounded-square icon containing “÷”, the title “Kalkulator Pro”, the subtitle “Lengkap, cepat, dan bergaya”, a sun/theme button, and a “Riwayat” history button. The UI should fit mobile portrait screens and adapt for short screens by reducing padding, display height, key height, and gaps. Also provide a light theme: pale blue-gray page background, white translucent card, dark text, pale display and keys, while retaining purple accents.

Below the header, show a large right-aligned display with a dark inset rounded rectangle. It has a smaller muted expression line above and a large result line initially showing “0”. The expression line shows the pending operation such as “12 +”, and the result line shows the current number. Format displayed computed/history numbers using Indonesian locale grouping with up to 10 fractional digits. Prevent overly long text from breaking the layout; clip with ellipses where appropriate.

Add a memory row with five small buttons: “MC” (memory clear), “MR” (memory recall), “M+” (add current number to memory), “M−” (subtract current number), and “MS” (store current number). Memory starts at zero and persists locally.

The main keypad is a four-column grid with rounded, raised buttons and pressed/hover feedback. Arrange it exactly as: top row AC, backspace “⌫”, percent “%”, division “÷”; then 7, 8, 9, multiplication “×”; then 4, 5, 6, subtraction “−”; then 1, 2, 3, addition “+”; final row a double-width 0, decimal “.”, and double-height-looking-width/equal-column “=”. AC is pink/red, operators are purple, and equals has a vivid purple-to-blue gradient with white text. Normal number keys are dark blue-gray. Buttons should have touch-friendly sizing, rounded corners, subtle shadows, hover lift, and active compression.

Implement standard calculator state with current input, previous operand, pending operator, and waiting-for-next-operand behavior. Digits replace the initial zero, append up to 16 characters, and begin a fresh operand after an operator or result. Decimal can be entered only once per current number. Selecting +, −, ×, or ÷ stores the current number and pending operator; selecting another operator while waiting replaces the operator. If an existing operation is pending, calculate it before chaining. Equals computes the pending binary operation, clears the pending state, leaves the result ready for a new input, and adds an entry to history. Support division by zero by displaying “Error” and resetting the pending operation appropriately. Round finite operation results to 10 decimal places. AC resets the calculator to 0; backspace removes the last digit unless waiting for an operand or displaying Error; percent divides the current value by 100.

Enable keyboard control globally: number keys input digits, period inputs a decimal, Enter or “=” evaluates, Escape clears, Backspace deletes, “%” applies percent, and +, -, *, / map to +, −, ×, ÷. Include the footer hint “Mode ilmiah • Keyboard aktif”, a scientific-mode toggle button labeled “Ilmiah”, and the small copyright/footer area is not required beyond the visible footer hint and controls.

When the user toggles scientific mode, reveal a four-column grid of smaller function buttons: x², √x, 1/x, x!, sin, cos, tan, log, ln, π, e, and ±. Toggle the button text to “Standar” when scientific mode is open and back to “Ilmiah” when closed. Scientific functions act on the current value and then wait for a new operand: square, nonnegative square root, reciprocal (Error for zero), factorial for nonnegative integers up to 170 (Error otherwise), base-10 log and natural log for positive values, and sin/cos/tan using degrees. π and e replace the current value with their constants, and ± negates it. Round finite scientific results to 10 decimal places.

The “Riwayat” button expands/collapses a history panel beneath the calculator. When expanded, show a heading “Perhitungan terakhir”, a red “Hapus semua” control, and up to the latest 20 entries, each with the formatted expression on the left and formatted result on the right. Initially show “Belum ada perhitungan”. Clearing history removes all entries. Persist history, memory, and selected light/dark theme in localStorage so they survive reloads. Render the calculator as a polished, accessible, touch-friendly app with live-updating result display and no external gameplay scenes or camera movement.