feat(binary): add full binary simulator with unsigned and two’s complement modes

- Introduce new Binary Simulator page with adjustable bit width (4–16 bits)
- Support unsigned and two’s complement representations with live conversion
- Add left/right shift operations and custom binary/denary input
- Implement accessible bulb-and-switch UI with MD3-inspired styling
- Add seven-segment display font assets for realistic number output
- Establish shared base layout, styles, and tooling for future simulators

Signed-off-by: Alexander Lyall <alex@adcm.uk>

public/css/tools/binary.css

@@ -0,0 +1,137 @@
+/* ---------- DSEG7 font ---------- */
+/* Put your font file here:
+   public/fonts/DSEG7Classic-Regular.woff2
+*/
+@font-face {
+  font-family: "DSEG7ClassicRegular";
+  src: url("/fonts/DSEG7Classic-Regular.woff2") format("woff2");
+  font-display: swap;
+}
+
+/* ---------- Layout ---------- */
+.tool-shell {
+  min-height: 100vh;
+  display: grid;
+  place-items: center;
+  padding: 1rem;
+  background: #0b0f14;
+  color: #e7eaf0;
+  font-family: system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
+}
+
+.tool-card {
+  width: min(1100px, 100%);
+  background: #111824;
+  border: 1px solid rgba(255,255,255,0.08);
+  border-radius: 18px;
+  padding: 1rem;
+}
+
+.tool-header h1 { margin: 0 0 .25rem 0; font-size: 1.4rem; }
+.tool-header p { margin: 0 0 1rem 0; opacity: .85; }
+
+.display-grid {
+  display: grid;
+  grid-template-columns: 1fr 1fr;
+  gap: .75rem;
+  margin-bottom: .75rem;
+}
+
+.display-box {
+  background: #0b0f14;
+  border: 1px solid rgba(255,255,255,0.08);
+  border-radius: 14px;
+  padding: .75rem;
+}
+
+.display-label { font-size: .9rem; opacity: .8; margin-bottom: .25rem; }
+
+.sevenseg {
+  font-family: "DSEG7ClassicRegular", monospace;
+  font-size: clamp(2rem, 4vw, 3.2rem);
+  letter-spacing: 0.08em;
+  line-height: 1.1;
+}
+
+/* Buttons under denary/binary (your request) */
+.actions {
+  display: flex;
+  flex-wrap: wrap;
+  gap: .5rem;
+  margin-bottom: 1rem;
+}
+
+/* ---------- Simple MD3-ish buttons ---------- */
+.md3-btn {
+  border: 1px solid rgba(255,255,255,0.16);
+  background: rgba(255,255,255,0.06);
+  color: #e7eaf0;
+  padding: .6rem .9rem;
+  border-radius: 999px;
+  cursor: pointer;
+  font-weight: 600;
+}
+.md3-btn:hover { background: rgba(255,255,255,0.10); }
+.md3-btn--tonal { background: rgba(255,255,255,0.10); }
+
+/* ---------- Switches row ---------- */
+.switch-row {
+  display: grid;
+  grid-template-columns: repeat(8, minmax(90px, 1fr));
+  gap: .75rem;
+}
+
+.switch-col {
+  display: grid;
+  justify-items: center;
+  gap: .35rem;
+}
+
+.bit-label { opacity: .85; font-weight: 600; }
+
+/* ---------- “Light switch” rocker ---------- */
+.rocker {
+  position: relative;
+  width: 70px;
+  height: 46px;
+  display: inline-block;
+  user-select: none;
+}
+
+.rocker input {
+  opacity: 0;
+  width: 0;
+  height: 0;
+}
+
+.rocker-body {
+  position: absolute;
+  inset: 0;
+  border-radius: 12px;
+  background: #1a2331;
+  border: 1px solid rgba(255,255,255,0.14);
+  box-shadow: inset 0 0 0 2px rgba(0,0,0,0.35);
+}
+
+/* the “toggle” */
+.rocker-body::after {
+  content: "";
+  position: absolute;
+  left: 6px;
+  top: 6px;
+  width: 58px;
+  height: 18px;
+  border-radius: 10px;
+  background: rgba(255,255,255,0.20);
+  transition: transform 180ms ease, background 180ms ease;
+}
+
+/* ON position */
+.rocker input:checked + .rocker-body::after {
+  transform: translateY(16px);
+  background: rgba(255,255,255,0.55);
+}
+
+@media (max-width: 900px) {
+  .switch-row { grid-template-columns: repeat(4, minmax(90px, 1fr)); }
+}

public/favicon.svg

@@ -0,0 +1,9 @@
+<svg xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 128 128">
+    <path d="M50.4 78.5a75.1 75.1 0 0 0-28.5 6.9l24.2-65.7c.7-2 1.9-3.2 3.4-3.2h29c1.5 0 2.7 1.2 3.4 3.2l24.2 65.7s-11.6-7-28.5-7L67 45.5c-.4-1.7-1.6-2.8-2.9-2.8-1.3 0-2.5 1.1-2.9 2.7L50.4 78.5Zm-1.1 28.2Zm-4.2-20.2c-2 6.6-.6 15.8 4.2 20.2a17.5 17.5 0 0 1 .2-.7 5.5 5.5 0 0 1 5.7-4.5c2.8.1 4.3 1.5 4.7 4.7.2 1.1.2 2.3.2 3.5v.4c0 2.7.7 5.2 2.2 7.4a13 13 0 0 0 5.7 4.9v-.3l-.2-.3c-1.8-5.6-.5-9.5 4.4-12.8l1.5-1a73 73 0 0 0 3.2-2.2 16 16 0 0 0 6.8-11.4c.3-2 .1-4-.6-6l-.8.6-1.6 1a37 37 0 0 1-22.4 2.7c-5-.7-9.7-2-13.2-6.2Z" />
+    <style>
+        path { fill: #000; }
+        @media (prefers-color-scheme: dark) {
+            path { fill: #FFF; }
+        }
+    </style>
+</svg>

public/js/binary/unsigned-binary.js

@@ -0,0 +1,115 @@
+// Browser-only script. Safe because it's loaded via <script> (not server-imported).
+
+const BIT_COUNT = 8; // unsigned page = 8 bits
+const bitValues = [128, 64, 32, 16, 8, 4, 2, 1];
+
+const elDenary = document.getElementById("denaryNumber");
+const elBinary = document.getElementById("binaryNumber");
+const elSwitches = document.getElementById("bitSwitches");
+
+const btnCustomDenary = document.getElementById("btnCustomDenary");
+const btnCustomBinary = document.getElementById("btnCustomBinary");
+const btnReset = document.getElementById("btnReset");
+
+let bits = new Array(BIT_COUNT).fill(false);
+
+function renderSwitches() {
+  elSwitches.innerHTML = "";
+
+  bitValues.forEach((value, index) => {
+    const id = `bit-${value}`;
+
+    const wrapper = document.createElement("div");
+    wrapper.className = "switch-col";
+
+    const labelTop = document.createElement("div");
+    labelTop.className = "bit-label";
+    labelTop.textContent = value;
+
+    const label = document.createElement("label");
+    label.className = "rocker";
+    label.setAttribute("for", id);
+
+    const input = document.createElement("input");
+    input.type = "checkbox";
+    input.id = id;
+    input.checked = bits[index];
+
+    input.addEventListener("change", () => {
+      bits[index] = input.checked;
+      updateNumbers();
+    });
+
+    const span = document.createElement("span");
+    span.className = "rocker-body";
+    span.setAttribute("aria-hidden", "true");
+
+    label.appendChild(input);
+    label.appendChild(span);
+
+    wrapper.appendChild(labelTop);
+    wrapper.appendChild(label);
+
+    elSwitches.appendChild(wrapper);
+  });
+}
+
+function updateNumbers() {
+  const binary = bits.map(b => (b ? "1" : "0")).join("");
+  const denary = bits.reduce((acc, b, i) => acc + (b ? bitValues[i] : 0), 0);
+
+  elBinary.textContent = binary;
+  elDenary.textContent = denary.toString();
+}
+
+function resetAll() {
+  bits = new Array(BIT_COUNT).fill(false);
+  renderSwitches();
+  updateNumbers();
+}
+
+function requestCustomDenary() {
+  let input = prompt(`Enter a denary number (0 to 255):`);
+  if (input === null) return;
+
+  const n = Number.parseInt(input, 10);
+  if (Number.isNaN(n) || n < 0 || n > 255) {
+    alert("Invalid input. Enter a number from 0 to 255.");
+    return;
+  }
+
+  let remaining = n;
+  bits = bitValues.map(v => {
+    if (remaining >= v) {
+      remaining -= v;
+      return true;
+    }
+    return false;
+  });
+
+  renderSwitches();
+  updateNumbers();
+}
+
+function requestCustomBinary() {
+  let input = prompt(`Enter an ${BIT_COUNT}-bit binary number (e.g. 01010101):`);
+  if (input === null) return;
+
+  input = input.trim();
+  const re = new RegExp(`^[01]{${BIT_COUNT}}$`);
+  if (!re.test(input)) {
+    alert(`Invalid input. Enter exactly ${BIT_COUNT} digits using only 0 or 1.`);
+    return;
+  }
+
+  bits = input.split("").map(c => c === "1");
+  renderSwitches();
+  updateNumbers();
+}
+
+btnCustomDenary?.addEventListener("click", requestCustomDenary);
+btnCustomBinary?.addEventListener("click", requestCustomBinary);
+btnReset?.addEventListener("click", resetAll);
+
+renderSwitches();
+updateNumbers();

public/js/tools/unsigned-binary.js

@@ -0,0 +1,72 @@
+// public/js/tools/unsigned-binary.js
+// Lightweight: no frameworks. Works on weak devices.
+const BIT_COUNT = 8;
+const MAX_DENARY = 255;
+let bits = new Array(BIT_COUNT).fill(false);
+function bitsToBinaryString(){
+ return bits.map(b => (b ? "1" : "0")).join("");
+}
+function bitsToDenary(){
+ // MSB on the left: 128..1
+ const weights = [128,64,32,16,8,4,2,1];
+ return bits.reduce((acc, b, i) => acc + (b ? weights[i] : 0), 0);
+}
+function render(){
+ const grid = document.getElementById("bitGrid");
+ grid.innerHTML = "";
+ const weights = [128,64,32,16,8,4,2,1];
+ bits.forEach((on, i) => {
+ const btn = document.createElement("button");
+ btn.type = "button";
+ btn.className = "btn";
+ btn.style.width = "100%";
+ btn.style.justifyContent = "space-between";
+ btn.setAttribute("aria-pressed", on ? "true" : "false");
+ btn.innerHTML = `<span>${weights[i]}</span><b>${on ? "1" : "0"}</b>`;
+ btn.addEventListener("click", () => {
+ bits[i] = !bits[i];
+ update();
+ });
+ grid.appendChild(btn);
+ });
+}
+function update(){
+ document.getElementById("binaryNumber").innerText = bitsToBinaryString();
+ document.getElementById("denaryNumber").innerText = bitsToDenary();
+ render();
+}
+function requestBinary(){
+ let v;
+ do{
+ v = prompt("Enter an 8-bit binary value (8 digits, only 0 or 1):", bitsToBinaryString());
+ if(v === null) return;
+ v = v.trim();
+ }while(!/^[01]{8}$/.test(v));
+ bits = v.split("").map(ch => ch === "1");
+ update();
+}
+function requestDenary(){
+ let v;
+ do{
+ v = prompt("Enter a denary value (0 to 255):", String(bitsToDenary()));
+ if(v === null) return;
+ v = Number(v);
+ }while(!Number.isInteger(v) || v < 0 || v > MAX_DENARY);
+ // set bits from MSB to LSB
+ const weights = [128,64,32,16,8,4,2,1];
+ bits = weights.map(w => {
+ if(v >= w){ v -= w; return true; }
+ return false;
+ });
+ update();
+}
+function reset(){
+ bits = new Array(BIT_COUNT).fill(false);
+ update();
+}
+document.addEventListener("DOMContentLoaded", () => {
+ document.getElementById("btnCustomBinary")?.addEventListener("click", requestBinary);
+ document.getElementById("btnCustomDenary")?.addEventListener("click", requestDenary);
+ document.getElementById("btnReset")?.addEventListener("click", reset);
+ update();
+});

public/styles.css

@@ -0,0 +1,96 @@
+/* src/styles/md3-tokens.css */
+/* MD3-inspired tokens tuned for education: high readability, clear contrast, calm surfaces */
+:root{
+ /* Typography */
+ --font-sans: system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
+ --font-mono: ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;
+ /* Spacing + shape */
+ --radius-1: 10px;
+ --radius-2: 16px;
+ --radius-3: 22px;
+ --shadow-1: 0 1px 2px rgba(0,0,0,.08), 0 2px 8px rgba(0,0,0,.06);
+ /* Color roles (keep simple) */
+ --md-surface: #ffffff;
+ --md-surface-2: #f6f7fb;
+ --md-on-surface: #111318;
+ --md-primary: #2f6fed; /* calm blue */
+ --md-on-primary: #ffffff;
+ --md-secondary: #5a5f72; /* muted */
+ --md-on-secondary: #ffffff;
+ --md-tertiary: #0f766e; /* teal for "practical" tools */
+ --md-on-tertiary: #ffffff;
+ --md-outline: #d7dbe7;
+ --md-success: #1a7f37;
+ --md-warning: #b54708;
+ --md-danger: #b42318;
+ /* Focus ring for accessibility */
+ --md-focus: 0 0 0 3px rgba(47,111,237,.28);
+}
+@media (prefers-color-scheme: dark){
+ :root{
+ --md-surface: #0b0e14;
+ --md-surface-2: #121725;
+ --md-on-surface: #e8eaf2;
+ --md-primary: #9bb6ff;
+ --md-on-primary: #0b0e14;
+ --md-secondary: #b8bccd;
+ --md-on-secondary: #0b0e14;
+ --md-tertiary: #4fd1c5;
+ --md-on-tertiary: #0b0e14;
+ --md-outline: #2b3244;
+ --md-focus: 0 0 0 3px rgba(155,182,255,.25);
+ }
+}
+
+/* src/styles/base.css */
+@import "./md3-tokens.css";
+html, body{ height:100%; }
+body{
+ margin:0;
+ font-family: var(--font-sans);
+ background: var(--md-surface-2);
+ color: var(--md-on-surface);
+}
+a{ color: var(--md-primary); text-decoration: none; }
+a:hover{ text-decoration: underline; }
+.container{
+ max-width: 1100px;
+ margin: 0 auto;
+ padding: 16px;
+}
+.card{
+ background: var(--md-surface);
+ border: 1px solid var(--md-outline);
+ border-radius: var(--radius-2);
+ box-shadow: var(--shadow-1);
+ padding: 16px;
+}
+.btn{
+ display:inline-flex;
+ gap:8px;
+ align-items:center;
+ justify-content:center;
+ border-radius: 999px;
+ border: 1px solid var(--md-outline);
+ background: var(--md-surface);
+ color: var(--md-on-surface);
+ padding: 10px 14px;
+ font-weight: 600;
+ cursor: pointer;
+}
+.btn:hover{ filter: brightness(0.98); }
+.btn:focus{ outline:none; box-shadow: var(--md-focus); }
+.btn-primary{
+ background: var(--md-primary);
+ color: var(--md-on-primary);
+ border-color: transparent;
+}
+.badge{
+ display:inline-block;
+ padding: 2px 10px;
+ border-radius: 999px;
+ font-size: 12px;
+ border: 1px solid var(--md-outline);
+ background: var(--md-surface-2);
+}
+code, pre{ font-family: var(--font-mono); }