HTML/CSS - Phyllotaxis - Draw With Math Online Editor and JavaScript Compiler

html

<!DOCTYPE html>
<html>
    <head>
        <title>Pattern</title>
    </head>
   
  <body style="background-color:#151515" link="#FF00FF font-color:"white">       <center><font color="#43FF3D">
<b>
 ~ Phyllotaxis ~    
 <br> <br>
</font>  
     <canvas id="can" height="400"  width="345"></canvas>
    <br><br>
<input type="range" id="cValue" min="50" value="150" max="250" step="10">     
<input id="clickMe" type="button" value="Reset" onclick="resetit();" /><input type="range" id="rValue" min="136.5" value="137.2" max="138.5" step=".1">   
<br>
<script>
var canvas=document.getElementById("can");
<!--https://lordhill.itch.io -->
var bg=canvas.getContext("2d");
bg.strokeStyle="black"; 
bg.fillRect(0,0,400,400);
var n=0; 
var c1=255;
var c2=0;
var c3=255;
var z=137.6;

css

BROWSER

Console