feat: add BackgroundTile component and it's colours in design system

src/app/[locale]/globals.css

@@ -36,6 +36,11 @@
   --button-primary-hover-bg: var(--color-neutral-50);
   --button-primary-hover-border: #121212;
   --button-subtle-bg: #9797971e;
+
+  /* Background Tile Colors */
+  --tile-bg: rgba(227, 226, 246);
+  --tile-stroke: rgba(80, 80, 80, 0.1);
+  --line-color: rgba(0, 0, 0, 0.05);
 }
 
 /* DARK MODE */
@@ -64,6 +69,11 @@
   --button-primary-hover-bg: var(--color-neutral-100);
   --button-primary-hover-border: var(--color-neutral-100);
   --button-subtle-bg: #bbbbbb0e;
+
+  /* Background Tile Colors */
+  --tile-bg: rgba(30, 29, 28);
+  --tile-stroke: rgba(80, 80, 80, 0.5);
+  --line-color: rgba(0, 0, 0, 0.2);
 }
 
 /* --- GLOBAL STYLES --- */
@@ -96,5 +106,4 @@ body {
 /* Dark Mode: Icon flips to White */
 :is(.dark .theme-icon) {
   filter: invert(1) brightness(100);
-}
-
+}

src/components/ui/BackgroundTile.tsx

@@ -0,0 +1,187 @@
+import { useEffect, useRef } from "react";
+
+// Stable random values generated once at module level — fixes "impure function in render" warning
+const PHASES = Array.from({ length: 6 }, () => Math.random() * Math.PI * 2);
+const FREQS  = Array.from({ length: 6 }, (_, i) => 0.3 + i * 0.13);
+
+interface BackgroundTileProps {
+  /** Height of the tile in viewport height units. Defaults to 50. */
+  heightVh?: number;
+}
+
+const BackgroundTile = ({ heightVh = 50 }: BackgroundTileProps) => {
+  const canvasRef   = useRef<HTMLCanvasElement>(null);
+  const rafRef      = useRef<number | null>(null);
+  const isRunning   = useRef(false);
+  const timeRef     = useRef(0);
+  const ampRef      = useRef(0);      // target amplitude
+  const ampSmoothed = useRef(0);      // smoothed amplitude (what's actually rendered)
+  const stopTimer   = useRef<ReturnType<typeof setTimeout> | null>(null);
+
+  useEffect(() => {
+    const canvas = canvasRef.current;
+    if (!canvas) return;
+
+    const ctx = canvas.getContext("2d");
+    if (!ctx) return;
+
+    // ── resize ────────────────────────────────────────────────────────
+    const setSize = () => {
+      const dpr     = window.devicePixelRatio || 1;
+      canvas.width  = canvas.offsetWidth  * dpr;
+      canvas.height = canvas.offsetHeight * dpr;
+      ctx.setTransform(dpr, 0, 0, dpr, 0, 0);
+    };
+    setSize();
+    const ro = new ResizeObserver(setSize);
+    ro.observe(canvas);
+
+    // ── render one frame ──────────────────────────────────────────────
+    const render = () => {
+      const w   = canvas.offsetWidth;
+      const h   = canvas.offsetHeight;
+      const amp = ampSmoothed.current;
+      const t   = timeRef.current;
+
+      ctx.clearRect(0, 0, w, h);
+
+      const N   = 6;
+      const pts = Array.from({ length: N }, (_, i) => {
+        const w1 = Math.sin(t * FREQS[i]        + PHASES[i])        * 0.50;
+        const w2 = Math.sin(t * FREQS[i] * 0.43 + PHASES[i] * 1.77) * 0.30;
+        const w3 = Math.cos(t * FREQS[i] * 0.27 + PHASES[i] * 0.85) * 0.20;
+        return {
+          x: (i / (N - 1)) * w,
+          y: h * 0.5 + (w1 + w2 + w3) * h * amp * 0.95,
+        };
+      });
+
+      ctx.beginPath();
+      ctx.moveTo(pts[0].x, pts[0].y);
+
+      for (let i = 0; i < N - 1; i++) {
+        const p0 = pts[Math.max(0, i - 1)];
+        const p1 = pts[i];
+        const p2 = pts[i + 1];
+        const p3 = pts[Math.min(N - 1, i + 2)];
+        const k  = 0.5;
+        ctx.bezierCurveTo(
+          p1.x + (p2.x - p0.x) * k / 3,
+          p1.y + (p2.y - p0.y) * k / 3,
+          p2.x - (p3.x - p1.x) * k / 3,
+          p2.y - (p3.y - p1.y) * k / 3,
+          p2.x, p2.y,
+        );
+      }
+
+      ctx.strokeStyle = getComputedStyle(document.documentElement).getPropertyValue("--line-color").trim();
+      ctx.lineWidth   = 14;
+      ctx.lineJoin    = "round";
+      ctx.lineCap     = "round";
+      ctx.stroke();
+    };
+
+    render(); // initial flat line
+
+    // ── loop — only alive while scrolling ─────────────────────────────
+    const tick = () => {
+      if (!isRunning.current) {
+        // Smoothly finish lerping to the frozen target, then stop
+        const target  = ampRef.current;
+        const current = ampSmoothed.current;
+        ampSmoothed.current += (target - current) * 0.18;
+
+        if (Math.abs(ampSmoothed.current - target) > 0.001) {
+          render();
+          rafRef.current = requestAnimationFrame(tick);
+        } else {
+          ampSmoothed.current = target; // snap to exact target
+          render();
+          rafRef.current = null;
+        }
+        return;
+      }
+
+      timeRef.current += 0.055;
+
+      // Lerp smoothed amp toward target — fast rise
+      const target  = ampRef.current;
+      const current = ampSmoothed.current;
+      ampSmoothed.current += (target - current) * 0.18;
+
+      render();
+      rafRef.current = requestAnimationFrame(tick);
+    };
+
+    const startLoop = () => {
+      if (!isRunning.current) {
+        isRunning.current = true;
+        if (rafRef.current === null) {
+          rafRef.current = requestAnimationFrame(tick);
+        }
+      }
+    };
+
+    const stopLoop = () => {
+      // Stop animating time — amplitude stays frozen at current ampRef value
+      isRunning.current = false;
+    };
+
+    // ── scroll / wheel ─────────────────────────────────────────────────
+    const onWheel = (e: WheelEvent) => {
+      const vel      = Math.min(Math.abs(e.deltaY) / 60, 1);
+      ampRef.current = 0.18 + vel * 0.74;
+      startLoop();
+      if (stopTimer.current) clearTimeout(stopTimer.current);
+      stopTimer.current = setTimeout(stopLoop, 80);
+    };
+
+    const onScroll = () => {
+      ampRef.current = 0.55;
+      startLoop();
+      if (stopTimer.current) clearTimeout(stopTimer.current);
+      stopTimer.current = setTimeout(stopLoop, 80);
+    };
+
+    window.addEventListener("wheel",  onWheel,  { passive: true });
+    window.addEventListener("scroll", onScroll, { passive: true });
+    canvas.addEventListener("wheel",  onWheel,  { passive: true });
+
+    return () => {
+      stopLoop();
+      ro.disconnect();
+      if (rafRef.current)    cancelAnimationFrame(rafRef.current);
+      if (stopTimer.current) clearTimeout(stopTimer.current);
+      window.removeEventListener("wheel",  onWheel);
+      window.removeEventListener("scroll", onScroll);
+      canvas.removeEventListener("wheel",  onWheel);
+    };
+  }, []);
+
+  return (
+    <div
+      style={{
+        background:   "var(--tile-bg, #1a1a1a)",
+        border:       "0.8px solid var(--tile-stroke, rgba(255,255,255,0.08))",
+        borderRadius: "24px",
+        width:        "100%",
+        height:       `${heightVh}vh`,
+        overflow:     "hidden",
+        position:     "relative",
+      }}
+    >
+      <canvas
+        ref={canvasRef}
+        style={{
+          position: "absolute",
+          inset:    0,
+          width:    "100%",
+          height:   "100%",
+          display:  "block",
+        }}
+      />
+    </div>
+  );
+};
+
+export default BackgroundTile;