<!DOCTYPE html> <html> <body> <canvas id="c" style="width:100%;height:90vh;background:#000"></canvas> <script> let c = document.getElementById('c'), a = c.getContext('2d'); c.width = window.innerWidth; c.height = window.innerHeight; a.lineWidth = 1; a.strokeStyle = 'rgba(200,0,255,0.7)'; function r() { a.clearRect(0, 0, c.width, c.height); a.beginPath(); for (let x = 0; x < c.width; x++) { let y = c.height / 2 + Math.sin(x / 100) * x / 3; a.lineTo(x, y); } a.stroke(); requestAnimationFrame(r); } r(); </script> </body> </