09Hero Scene Combining Every Ball-Physics Technique

<main class="stage">
<div class="bp is-demo" id="bpRoot" tabindex="0">
  <canvas class="bp__canvas" id="bpCanvas" width="480" height="300"></canvas>
  <p class="bp__caption">Gravity, floor bounce, elastic ball-to-ball collision, and pointer repulsion all combine in one scene, so the balls drop, bounce, collide, and scatter together.</p>
</div>
</main>

@use "../../../../site/static/demo-tokens" as *;
@include stage($stage-ink);

.bp {
  position: relative;
  width: min(92vw, calc(160vh - 12.8vw));
  aspect-ratio: 480 / 300;
  margin: 0 auto;
  border-radius: $r-card;
  overflow: hidden;
  box-shadow: $shadow-raised;
  background: $stage-ink;
  cursor: none;
}

.bp__canvas {
  display: block;
  width: 100%;
  height: 100%;
}

.bp__caption {
  position: absolute;
  left: $sp-3;
  bottom: $sp-3;
  max-width: 80%;
  margin: 0;
  padding: $sp-1 $sp-3;
  border-radius: $r-pill;
  background: rgba(255, 255, 255, .85);
  color: $subject-ink;
  font-weight: 500;
  font-size: 12px;
  line-height: 1.4;
  pointer-events: none;
}

@media (max-width: 340px) {
  .bp__caption { font-size: 10px; padding: $sp-1 $sp-2; }
}

@media (prefers-reduced-motion: reduce) {
  .bp { cursor: default; }
}

html, body {
  margin: 0;
  overflow: hidden;
}

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #17141a;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.bp {
  position: relative;
  width: min(92vw, 160vh - 12.8vw);
  aspect-ratio: 480/300;
  margin: 0 auto;
  border-radius: 16px;
  overflow: hidden;
  box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
  background: #17141a;
  cursor: none;
}

.bp__canvas {
  display: block;
  width: 100%;
  height: 100%;
}

.bp__caption {
  position: absolute;
  left: 12px;
  bottom: 12px;
  max-width: 80%;
  margin: 0;
  padding: 4px 12px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.85);
  color: #17141a;
  font-weight: 500;
  font-size: 12px;
  line-height: 1.4;
  pointer-events: none;
}

@media (max-width: 340px) {
  .bp__caption {
    font-size: 10px;
    padding: 4px 8px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .bp {
    cursor: default;
  }
}

(function () {
  // 기법: 앞선 세 항목의 계산을 한 장면에 합성한다 — ①매 스텝 HERO_GRAVITY 로 속도
  // 적분(항목 02) ②포인터 반경 안이면 거리 반비례 힘으로 밀어냄(항목 05) ③위치 적분
  // 뒤 벽·바닥에서 HERO_WALL_RESTITUTION 으로 반사, 공끼리는 질량비 임펄스로 탄성
  // 충돌(항목 01) 한다. 상수 이름을 HERO_ 접두사로 통일해 세 계산이 한 루프 안에서
  // 섞여도 출처를 구분할 수 있게 했다.
  var root = document.getElementById('bpRoot');
  var canvas = document.getElementById('bpCanvas');
  var ctx = canvas.getContext('2d');
  var wrap = canvas.parentElement;

  var CALC_W = 320, CALC_H = 200;
  var HERO_GRAVITY = 620;
  var HERO_RESTITUTION = 0.78;
  var HERO_WALL_RESTITUTION = 0.6;
  var HERO_POINTER_REPEL_RADIUS = 78;
  var HERO_POINTER_FORCE = 3600;

  function seedRand(seed) {
    var s = seed >>> 0;
    return function () { s = (s * 1664525 + 1013904223) >>> 0; return s / 4294967296; };
  }
  var rand = seedRand(427091);

  var COLORS = ['#6ec8ff', '#4cd4a6', '#b9a0ff', '#ff9ebb', '#ffcf7a'];
  var RADII = [12, 15, 18, 13, 16];
  var balls = [];
  function initBalls() {
    balls = [];
    for (var i = 0; i < RADII.length; i += 1) {
      var r = RADII[i];
      balls.push({
        x: 40 + i * ((CALC_W - 80) / (RADII.length - 1)),
        y: 20 + rand() * 40,
        vx: (rand() - 0.5) * 60,
        vy: 0,
        r: r, mass: r,
        color: COLORS[i],
        squash: 0
      });
    }
  }
  initBalls();

  var pointer = { x: CALC_W * 0.5, y: CALC_H * 0.35 };
  var pointerActive = false;
  var impacts = [];

  function demoPointerPos(t) {
    var tt = t / 1000;
    return {
      x: CALC_W * 0.5 + Math.cos(tt * 0.9) * (CALC_W * 0.32),
      y: CALC_H * 0.38 + Math.sin(tt * 1.3) * (CALC_H * 0.2)
    };
  }

  function resolvePair(a, b, nowMs) {
    var dx = b.x - a.x, dy = b.y - a.y;
    var dist = Math.hypot(dx, dy);
    var minDist = a.r + b.r;
    if (dist === 0 || dist >= minDist) return;
    var nx = dx / dist, ny = dy / dist;
    var overlap = minDist - dist;
    var totalMass = a.mass + b.mass;
    a.x -= nx * overlap * (b.mass / totalMass);
    a.y -= ny * overlap * (b.mass / totalMass);
    b.x += nx * overlap * (a.mass / totalMass);
    b.y += ny * overlap * (a.mass / totalMass);
    var rvx = b.vx - a.vx, rvy = b.vy - a.vy;
    var velAlongNormal = rvx * nx + rvy * ny;
    if (velAlongNormal > 0) return;
    var j = -(1 + HERO_RESTITUTION) * velAlongNormal / (1 / a.mass + 1 / b.mass);
    var ix = j * nx, iy = j * ny;
    a.vx -= ix / a.mass; a.vy -= iy / a.mass;
    b.vx += ix / b.mass; b.vy += iy / b.mass;
    var strength = Math.min(1, Math.abs(velAlongNormal) / 300);
    a.squash = Math.max(a.squash, strength);
    b.squash = Math.max(b.squash, strength);
    impacts.push({ x: (a.x + b.x) / 2, y: (a.y + b.y) / 2, born: nowMs, strength: strength });
  }

  function stepSim(dtMs, nowMs, px, py) {
    var dtS = dtMs / 1000;
    for (var i = 0; i < balls.length; i += 1) {
      var b = balls[i];
      b.vy += HERO_GRAVITY * dtS;
      var dx = b.x - px, dy = b.y - py;
      var dist = Math.hypot(dx, dy) || 0.001;
      if (dist < HERO_POINTER_REPEL_RADIUS) {
        var force = HERO_POINTER_FORCE * (1 - dist / HERO_POINTER_REPEL_RADIUS) / dist;
        b.vx += dx * force * dtS;
        b.vy += dy * force * dtS;
      }
      b.x += b.vx * dtS;
      b.y += b.vy * dtS;
      var hit = false;
      if (b.x - b.r < 0) { b.x = b.r; b.vx = -b.vx * HERO_WALL_RESTITUTION; hit = true; }
      if (b.x + b.r > CALC_W) { b.x = CALC_W - b.r; b.vx = -b.vx * HERO_WALL_RESTITUTION; hit = true; }
      if (b.y - b.r < 0) { b.y = b.r; b.vy = -b.vy * HERO_WALL_RESTITUTION; hit = true; }
      if (b.y + b.r > CALC_H) {
        b.y = CALC_H - b.r;
        b.vy = -b.vy * HERO_WALL_RESTITUTION;
        if (Math.abs(b.vy) < 24) b.vy = 0;
        hit = true;
      }
      if (hit) b.squash = Math.max(b.squash, Math.min(0.75, Math.hypot(b.vx, b.vy) / 300));
      b.squash = Math.max(0, b.squash - dtS * 3.2);
    }
    for (var a = 0; a < balls.length; a += 1) {
      for (var c = a + 1; c < balls.length; c += 1) resolvePair(balls[a], balls[c], nowMs);
    }
    var live = [];
    for (var k = 0; k < impacts.length; k += 1) { if (nowMs - impacts[k].born < 240) live.push(impacts[k]); }
    impacts = live;
  }

  function draw(px, py) {
    var sx = cw / CALC_W, sy = ch / CALC_H;
    ctx.fillStyle = 'rgba(23,20,26,0.22)';
    ctx.fillRect(0, 0, cw, ch);
    for (var i = 0; i < impacts.length; i += 1) {
      var im = impacts[i];
      ctx.beginPath();
      ctx.arc(im.x * sx, im.y * sy, (6 + im.strength * 14) * ((sx + sy) / 2), 0, Math.PI * 2);
      ctx.strokeStyle = 'rgba(255,255,255,' + (im.strength * 0.4) + ')';
      ctx.lineWidth = 2;
      ctx.stroke();
    }
    for (var j = 0; j < balls.length; j += 1) {
      var b = balls[j];
      var ppx = b.x * sx, ppy = b.y * sy, pr = b.r * ((sx + sy) / 2);
      var shf = Math.max(0, 1 - (CALC_H - b.r - b.y) / 110);
      ctx.beginPath();
      ctx.ellipse(ppx, (CALC_H - 3) * sy, pr * (0.9 + shf * 0.3), pr * 0.22, 0, 0, Math.PI * 2);
      ctx.fillStyle = 'rgba(0,0,0,' + (0.1 + shf * 0.14) + ')';
      ctx.fill();
      var sqX = 1 + b.squash * 0.45, sqY = 1 - b.squash * 0.32;
      ctx.save();
      ctx.translate(ppx, ppy);
      ctx.scale(sqX, sqY);
      ctx.beginPath();
      ctx.arc(0, 0, pr, 0, Math.PI * 2);
      ctx.fillStyle = b.color;
      ctx.fill();
      ctx.restore();
    }
    ctx.beginPath();
    ctx.arc(px * sx, py * sy, 3, 0, Math.PI * 2);
    ctx.fillStyle = 'rgba(255,255,255,0.65)';
    ctx.fill();
  }

  var cw = 480, ch = 300;
  function fit() {
    var r = wrap.getBoundingClientRect();
    cw = Math.max(1, Math.round(r.width));
    ch = Math.max(1, Math.round(r.height));
    canvas.width = cw; canvas.height = ch;
    draw(pointer.x, pointer.y);
  }

  var reduce = window.matchMedia('(prefers-reduced-motion: reduce)').matches;
  var elapsed = 0;
  if (reduce) root.classList.remove('is-demo');

  function toCalc(clientX, clientY) {
    var rect = canvas.getBoundingClientRect();
    var nx = (clientX - rect.left) / rect.width;
    var ny = (clientY - rect.top) / rect.height;
    return { x: Math.max(0, Math.min(CALC_W, nx * CALC_W)), y: Math.max(0, Math.min(CALC_H, ny * CALC_H)) };
  }

  function onRealPointer(cx, cy) {
    pointerActive = true;
    root.classList.remove('is-demo');
    var p = toCalc(cx, cy);
    pointer.x = p.x; pointer.y = p.y;
    if (reduce) { stepSim(16, elapsed, pointer.x, pointer.y); draw(pointer.x, pointer.y); }
  }
  canvas.addEventListener('mousemove', function (e) { onRealPointer(e.clientX, e.clientY); });
  canvas.addEventListener('touchmove', function (e) {
    if (e.touches && e.touches[0]) onRealPointer(e.touches[0].clientX, e.touches[0].clientY);
  }, { passive: true });

  root.addEventListener('keydown', function (e) {
    var step = 14;
    var moved = true;
    if (e.key === 'ArrowLeft') pointer.x -= step;
    else if (e.key === 'ArrowRight') pointer.x += step;
    else if (e.key === 'ArrowUp') pointer.y -= step;
    else if (e.key === 'ArrowDown') pointer.y += step;
    else moved = false;
    if (moved) {
      e.preventDefault();
      pointerActive = true;
      root.classList.remove('is-demo');
      pointer.x = Math.max(0, Math.min(CALC_W, pointer.x));
      pointer.y = Math.max(0, Math.min(CALC_H, pointer.y));
      if (reduce) { stepSim(16, elapsed, pointer.x, pointer.y); draw(pointer.x, pointer.y); }
    }
  });

  var lastTs = null;
  var acc = 0;
  var FIXED_DT = 16;
  var cycleStart = 0;
  function tick(ts) {
    if (lastTs === null) lastTs = ts;
    var frameDt = Math.min(ts - lastTs, 48);
    lastTs = ts;
    if (!reduce) {
      acc += frameDt;
      while (acc >= FIXED_DT) {
        elapsed += FIXED_DT;
        var pp = pointerActive ? pointer : demoPointerPos(elapsed);
        if (!pointerActive) { pointer.x = pp.x; pointer.y = pp.y; }
        stepSim(FIXED_DT, elapsed, pointer.x, pointer.y);
        if (elapsed - cycleStart > 2600) { cycleStart = elapsed; initBalls(); }
        acc -= FIXED_DT;
      }
      draw(pointer.x, pointer.y);
    }
    requestAnimationFrame(tick);
  }
  fit();
  window.addEventListener('resize', fit);
  draw(pointer.x, pointer.y);
  requestAnimationFrame(tick);
})();

import { useEffect, useRef } from "react";
import styles from "./BallPhysicsHeroScene.module.scss";

type Ball = { x: number; y: number; vx: number; vy: number; r: number; mass: number; color: string; squash: number };
type Impact = { x: number; y: number; born: number; strength: number };

export default function BallPhysicsHeroScene() {
  const rootRef = useRef<HTMLDivElement>(null);
  const canvasRef = useRef<HTMLCanvasElement>(null);

  useEffect(() => {
    const root = rootRef.current;
    const canvas = canvasRef.current;
    if (!root || !canvas) return;
    const ctx = canvas.getContext("2d");
    if (!ctx) return;
    const wrap = canvas.parentElement as HTMLElement;

    const CALC_W = 320, CALC_H = 200;
    const HERO_GRAVITY = 620;
    const HERO_RESTITUTION = 0.78;
    const HERO_WALL_RESTITUTION = 0.6;
    const HERO_POINTER_REPEL_RADIUS = 78;
    const HERO_POINTER_FORCE = 3600;

    function seedRand(seed: number) {
      let s = seed >>> 0;
      return function () { s = (s * 1664525 + 1013904223) >>> 0; return s / 4294967296; };
    }
    const rand = seedRand(427091);

    const COLORS = ["#6ec8ff", "#4cd4a6", "#b9a0ff", "#ff9ebb", "#ffcf7a"];
    const RADII = [12, 15, 18, 13, 16];
    let balls: Ball[] = [];
    function initBalls() {
      balls = RADII.map((r, i) => ({
        x: 40 + i * ((CALC_W - 80) / (RADII.length - 1)),
        y: 20 + rand() * 40,
        vx: (rand() - 0.5) * 60,
        vy: 0,
        r, mass: r, color: COLORS[i], squash: 0
      }));
    }
    initBalls();

    const pointer = { x: CALC_W * 0.5, y: CALC_H * 0.35 };
    let pointerActive = false;
    let impacts: Impact[] = [];

    function demoPointerPos(t: number) {
      const tt = t / 1000;
      return {
        x: CALC_W * 0.5 + Math.cos(tt * 0.9) * (CALC_W * 0.32),
        y: CALC_H * 0.38 + Math.sin(tt * 1.3) * (CALC_H * 0.2)
      };
    }

    function resolvePair(a: Ball, b: Ball, nowMs: number) {
      const dx = b.x - a.x, dy = b.y - a.y;
      const dist = Math.hypot(dx, dy);
      const minDist = a.r + b.r;
      if (dist === 0 || dist >= minDist) return;
      const nx = dx / dist, ny = dy / dist;
      const overlap = minDist - dist;
      const totalMass = a.mass + b.mass;
      a.x -= nx * overlap * (b.mass / totalMass);
      a.y -= ny * overlap * (b.mass / totalMass);
      b.x += nx * overlap * (a.mass / totalMass);
      b.y += ny * overlap * (a.mass / totalMass);
      const rvx = b.vx - a.vx, rvy = b.vy - a.vy;
      const velAlongNormal = rvx * nx + rvy * ny;
      if (velAlongNormal > 0) return;
      const j = -(1 + HERO_RESTITUTION) * velAlongNormal / (1 / a.mass + 1 / b.mass);
      const ix = j * nx, iy = j * ny;
      a.vx -= ix / a.mass; a.vy -= iy / a.mass;
      b.vx += ix / b.mass; b.vy += iy / b.mass;
      const strength = Math.min(1, Math.abs(velAlongNormal) / 300);
      a.squash = Math.max(a.squash, strength);
      b.squash = Math.max(b.squash, strength);
      impacts.push({ x: (a.x + b.x) / 2, y: (a.y + b.y) / 2, born: nowMs, strength });
    }

    function stepSim(dtMs: number, nowMs: number, px: number, py: number) {
      const dtS = dtMs / 1000;
      for (const b of balls) {
        b.vy += HERO_GRAVITY * dtS;
        const dx = b.x - px, dy = b.y - py;
        const dist = Math.hypot(dx, dy) || 0.001;
        if (dist < HERO_POINTER_REPEL_RADIUS) {
          const force = (HERO_POINTER_FORCE * (1 - dist / HERO_POINTER_REPEL_RADIUS)) / dist;
          b.vx += dx * force * dtS;
          b.vy += dy * force * dtS;
        }
        b.x += b.vx * dtS;
        b.y += b.vy * dtS;
        let hit = false;
        if (b.x - b.r < 0) { b.x = b.r; b.vx = -b.vx * HERO_WALL_RESTITUTION; hit = true; }
        if (b.x + b.r > CALC_W) { b.x = CALC_W - b.r; b.vx = -b.vx * HERO_WALL_RESTITUTION; hit = true; }
        if (b.y - b.r < 0) { b.y = b.r; b.vy = -b.vy * HERO_WALL_RESTITUTION; hit = true; }
        if (b.y + b.r > CALC_H) {
          b.y = CALC_H - b.r;
          b.vy = -b.vy * HERO_WALL_RESTITUTION;
          if (Math.abs(b.vy) < 24) b.vy = 0;
          hit = true;
        }
        if (hit) b.squash = Math.max(b.squash, Math.min(0.75, Math.hypot(b.vx, b.vy) / 300));
        b.squash = Math.max(0, b.squash - dtS * 3.2);
      }
      for (let a = 0; a < balls.length; a += 1) {
        for (let c = a + 1; c < balls.length; c += 1) resolvePair(balls[a], balls[c], nowMs);
      }
      impacts = impacts.filter((im) => nowMs - im.born < 240);
    }

    let cw = 480, ch = 300;
    function draw(px: number, py: number) {
      const sx = cw / CALC_W, sy = ch / CALC_H;
      ctx!.fillStyle = "rgba(23,20,26,0.22)";
      ctx!.fillRect(0, 0, cw, ch);
      for (const im of impacts) {
        ctx!.beginPath();
        ctx!.arc(im.x * sx, im.y * sy, (6 + im.strength * 14) * ((sx + sy) / 2), 0, Math.PI * 2);
        ctx!.strokeStyle = "rgba(255,255,255," + (im.strength * 0.4) + ")";
        ctx!.lineWidth = 2;
        ctx!.stroke();
      }
      for (const b of balls) {
        const ppx = b.x * sx, ppy = b.y * sy, pr = b.r * ((sx + sy) / 2);
        const shf = Math.max(0, 1 - (CALC_H - b.r - b.y) / 110);
        ctx!.beginPath();
        ctx!.ellipse(ppx, (CALC_H - 3) * sy, pr * (0.9 + shf * 0.3), pr * 0.22, 0, 0, Math.PI * 2);
        ctx!.fillStyle = "rgba(0,0,0," + (0.1 + shf * 0.14) + ")";
        ctx!.fill();
        const sqX = 1 + b.squash * 0.45, sqY = 1 - b.squash * 0.32;
        ctx!.save();
        ctx!.translate(ppx, ppy);
        ctx!.scale(sqX, sqY);
        ctx!.beginPath();
        ctx!.arc(0, 0, pr, 0, Math.PI * 2);
        ctx!.fillStyle = b.color;
        ctx!.fill();
        ctx!.restore();
      }
      ctx!.beginPath();
      ctx!.arc(px * sx, py * sy, 3, 0, Math.PI * 2);
      ctx!.fillStyle = "rgba(255,255,255,0.65)";
      ctx!.fill();
    }

    function fit() {
      const r = wrap.getBoundingClientRect();
      cw = Math.max(1, Math.round(r.width));
      ch = Math.max(1, Math.round(r.height));
      canvas!.width = cw; canvas!.height = ch;
      draw(pointer.x, pointer.y);
    }

    const reduce = window.matchMedia("(prefers-reduced-motion: reduce)").matches;
    let elapsed = 0;
    if (reduce) root.classList.remove("is-demo");

    function toCalc(clientX: number, clientY: number) {
      const rect = canvas!.getBoundingClientRect();
      const nx = (clientX - rect.left) / rect.width;
      const ny = (clientY - rect.top) / rect.height;
      return { x: Math.max(0, Math.min(CALC_W, nx * CALC_W)), y: Math.max(0, Math.min(CALC_H, ny * CALC_H)) };
    }

    function onRealPointer(cx: number, cy: number) {
      pointerActive = true;
      root!.classList.remove("is-demo");
      const p = toCalc(cx, cy);
      pointer.x = p.x; pointer.y = p.y;
      if (reduce) { stepSim(16, elapsed, pointer.x, pointer.y); draw(pointer.x, pointer.y); }
    }
    function onMouseMove(e: MouseEvent) { onRealPointer(e.clientX, e.clientY); }
    function onTouchMove(e: TouchEvent) { if (e.touches[0]) onRealPointer(e.touches[0].clientX, e.touches[0].clientY); }
    canvas.addEventListener("mousemove", onMouseMove);
    canvas.addEventListener("touchmove", onTouchMove, { passive: true });

    function onKeyDown(e: KeyboardEvent) {
      const step = 14;
      let moved = true;
      if (e.key === "ArrowLeft") pointer.x -= step;
      else if (e.key === "ArrowRight") pointer.x += step;
      else if (e.key === "ArrowUp") pointer.y -= step;
      else if (e.key === "ArrowDown") pointer.y += step;
      else moved = false;
      if (moved) {
        e.preventDefault();
        pointerActive = true;
        root!.classList.remove("is-demo");
        pointer.x = Math.max(0, Math.min(CALC_W, pointer.x));
        pointer.y = Math.max(0, Math.min(CALC_H, pointer.y));
        if (reduce) { stepSim(16, elapsed, pointer.x, pointer.y); draw(pointer.x, pointer.y); }
      }
    }
    root.addEventListener("keydown", onKeyDown);

    let lastTs: number | null = null;
    let acc = 0;
    const FIXED_DT = 16;
    let cycleStart = 0;
    let raf = 0;
    function tick(ts: number) {
      if (lastTs === null) lastTs = ts;
      const frameDt = Math.min(ts - lastTs, 48);
      lastTs = ts;
      if (!reduce) {
        acc += frameDt;
        while (acc >= FIXED_DT) {
          elapsed += FIXED_DT;
          const pp = pointerActive ? pointer : demoPointerPos(elapsed);
          if (!pointerActive) { pointer.x = pp.x; pointer.y = pp.y; }
          stepSim(FIXED_DT, elapsed, pointer.x, pointer.y);
          if (elapsed - cycleStart > 2600) { cycleStart = elapsed; initBalls(); }
          acc -= FIXED_DT;
        }
        draw(pointer.x, pointer.y);
      }
      raf = requestAnimationFrame(tick);
    }
    fit();
    window.addEventListener("resize", fit);
    draw(pointer.x, pointer.y);
    raf = requestAnimationFrame(tick);

    return () => {
      cancelAnimationFrame(raf);
      window.removeEventListener("resize", fit);
      canvas!.removeEventListener("mousemove", onMouseMove);
      canvas!.removeEventListener("touchmove", onTouchMove);
      root!.removeEventListener("keydown", onKeyDown);
    };
  }, []);

  return (
    <main className={styles.stage}>
      <div className={`${styles.bp} is-demo`} ref={rootRef} tabIndex={0}>
        <canvas className={styles.bp__canvas} ref={canvasRef} width={480} height={300} />
        <p className={styles.bp__caption}>중력·바닥 반발·공끼리 탄성 충돌·포인터 밀어내기를 한 장면에 합쳐, 공들이 떨어지고 튕기고 부딪히고 흩어진다</p>
      </div>
    </main>
  );
}