refactor(samples/calc-02): simplify layout to portrait-only single column

Remove the responsive two-column desktop arrangement and make the calculator stack vertically with a 4-column display button row that preserves alignment. Also align the display buttons with the shared base button styling.

.memory/state.md

@@ -1,9 +1,9 @@
 # State
 - Core engine: `src/rpn-calculator.js`
-- Active demo: `samples/calc-02/` responsive HP48GX layout with portrait/landscape support; display-adjacent button row stays in 4 columns
+- Active demo: `samples/calc-02/` portrait-only HP48GX layout; display-adjacent button row stays in 4 columns and now shares the same base button styling as the function keys
 - Mode button shows the current angle mode only; selecting a mode uses a popup menu
 - Public API: `push`, `pop`, `clear`, `swap`, `remove`, `edit`, `isValidIndex`, `input`, `command`, `getOperationsByCategory`, `getConstants`
 - Config: `maxSize`, `base`, `angleMode`, `enabledCommands`
 - Commands: arithmetic, stack, trigonometry, constants `pi` and `e`; arithmetic now includes `root` for y-th roots
-- Demo actions: keyboard focus is kept on the hidden input on desktop so typing keeps working; the keypad layout places Enter in the bottom-left, ± in the former Enter position, and Esc before Clear for safety; paste parses clipboard text as a number before pushing it to the stack; Ctrl+V is supported via the hidden input paste event; backspace is ignored when the stack is empty; operation errors are shown as an overlay bar on top of the calculator with a shorter timeout and darker red
+- Demo actions: keyboard focus is kept on the hidden input on desktop so typing keeps working; the keypad layout places Enter in the bottom-left, ± in the former Enter position, and Esc before Clear for safety; paste parses clipboard text as a number before pushing it to the stack; Ctrl+V is supported via the hidden input paste event; backspace is ignored when the stack is empty; operation errors are shown as an overlay bar on top of the calculator with a shorter timeout and darker red; the display button row uses a 4-column grid with a spacer cell to preserve alignment
 - Exports: browser `window.RpnCalculator`, CommonJS `module.exports`

samples/calc-02/index.css

@@ -51,23 +51,23 @@ body {
 
 .calculator {
 	width: 100%;
-	height: 100%;
+	height: auto;
+	min-height: 100%;
 	display: grid;
 	padding: 8px;
 	border-radius: 8px;
 	background: linear-gradient(180deg, var(--panel2), var(--panel));
 	border: 1px solid var(--edge);
 	box-shadow: 0 26px 70px var(--shadow), inset 0 1px 0 rgba(255, 255, 255, 0.08);
-	grid-template-columns: 1.3fr 0.9fr;
+	grid-template-columns: 1fr;
-	grid-template-rows: minmax(0, 0.62fr) min-content minmax(180px, 1fr) minmax(180px, 1fr);
+	grid-template-rows: auto auto auto auto auto;
-	align-content: start;
+	row-gap: 6px;
 	grid-template-areas:
-		"display functions"
+		"display"
-		"display functions"
+		"display-buttons"
-		"keypad functions"
+		"keypad"
-		"keypad trigo";
+		"functions"
-	row-gap: 0;
+		"trigo";
-	column-gap: clamp(10px, 1.4vw, 18px);
 }
 
 .display-block,
@@ -113,7 +113,6 @@ body {
 	padding: 0;
 }
 
-
 .display-grid {
 	height: 100%;
 	display: grid;
@@ -188,7 +187,6 @@ body {
 	border-radius: 8px;
 		background: rgba(18, 24, 33, 0.98);
 	border: 1px solid rgba(255, 255, 255, 0.08);
-
 	box-shadow: 0 14px 30px rgba(0, 0, 0, 0.35);
 }
 
@@ -368,7 +366,6 @@ button:active {
 	outline-offset: 2px;
 }
 
-
 .key-default {
 	background: linear-gradient(180deg, var(--btnTop), var(--btnBottom));
 	color: #eef2f7;
@@ -403,70 +400,4 @@ button:active {
 	pointer-events: none;
 }
 
-@media (orientation: portrait), (max-width: 860px) {
-	.calculator {
-		width: 100%;
-		height: auto;
-		min-height: 100%;
-		grid-template-columns: 1fr;
-		grid-template-rows: minmax(0px, auto) auto auto auto;
-		row-gap: 6px;
-		grid-template-areas:
-			"display"
-			"display-buttons"
-			"keypad"
-			"functions"
-			"trigo";
-	}
 
-	.display-buttons-grid {
-		grid-template-columns: repeat(4, minmax(0, 1fr));
-	}
-
-	.keypad-grid {
-		grid-template-rows: repeat(5, minmax(42px, 1fr));
-	}
-
-	.functions-grid,
-	.trigo-grid {
-		grid-auto-rows: minmax(0, auto);
-		grid-template-rows: repeat(2, minmax(0, 1fr));
-	}
-}
-
-@media (max-width: 520px) {
-	.app-shell {
-		padding: 0;
-	}
-
-	.calculator {
-		width: 100%;
-		min-height: 100%;
-		border-radius: 8px;
-		padding: 8px;
-		gap: 12px;
-	}
-
-	.display-panel {
-		padding: 8px;
-		padding-bottom: 8px;
-	}
-
-	.stack-cell {
-		font-size: clamp(16px, 5.2vw, 22px);
-		gap: 8px;
-	}
-
-	.stack-copy-button {
-		padding: 4px;
-		min-width: 24px;
-	}
-
-	button {
-		border-radius: 8px;
-		padding: 10px 8px;
-		font-size: 13px;
-		line-height: 1;
-	}
-
-}

samples/calc-02/index.html

@@ -25,13 +25,13 @@
 
 			<div class="display-buttons-panel">
 				<div class="display-buttons-grid">
-					<button id="modeButton" class="display-button key-default">Mode</button>
+					<button id="modeButton" class="display-button">Mode</button>
-					<button id="pasteButton" class="display-button key-default">⎘</button>
+					<button id="pasteButton" class="display-button">⎘</button>
-					<button id="upButton" class="display-button key-default">↑</button>
+					<button id="upButton" class="display-button">↑</button>
-					<button id="constButton" class="display-button key-default">π</button>
+					<button id="constButton" class="display-button">π</button>
-					<button id="leftButton" class="display-button key-default display-button-offset">←</button>
+					<button id="leftButton" class="display-button display-button-offset">←</button>
-					<button id="downButton" class="display-button key-default">↓</button>
+					<button id="downButton" class="display-button">↓</button>
-					<button id="rightButton" class="display-button key-default">→</button>
+					<button id="rightButton" class="display-button">→</button>
 					<div class="display-button-spacer"></div>
 				</div>
 			</div>

samples/calc-02/index.js

@@ -228,7 +228,6 @@ function execute(name) {
 			} else if (calc.isValidIndex(0)) {
 				calc.remove(0);
 			}
-
 		} else if (name === 'swap') {
 			pushEditingValueIfNeeded();
 			if (calc.isValidIndex(1)) {
@@ -489,12 +488,10 @@ downButton.addEventListener('click', () => {
 	}
 });
 
-
 rightButton.addEventListener('click', () => {
 	execute('swap');
 });
 
-
 window.addEventListener('keydown', handleKeyboard, { capture: true });
 window.addEventListener('load', focusInput);
 window.addEventListener('pageshow', focusInput);