var svg = document.getElementById('svg');
var NS = 'http://www.w3.org/2000/svg';
function se(t){ return document.createElementNS(NS,t); }
function sa(e,o){ for (var k in o) e.setAttribute(k,o[k]); }
function R(a,b){ return a + Math.random()*(b-a); }
var CATS = ['A','B','C','D','E','F'];
var cur = CATS.map(function(){ return 0; });
var W = 300, H = 200;
function measure(){
var r = svg.getBoundingClientRect();
W = Math.max(r.width,10); H = Math.max(r.height,10);
sa(svg,{ viewBox: '0 0 ' + W + ' ' + H });
}
function draw(){
svg.innerHTML = '';
var padL=26, padR=10, padT=18, padB=22;
var pw=W-padL-padR, ph=H-padT-padB;
var maxV=100, n=CATS.length;
var fs = Math.max(8, Math.min(13, W/70));
var gap = pw*0.16/n;
var bw = Math.min(34,(pw-gap*(n-1))/n);
var totalW = bw*n+gap*(n-1);
var startX = padL+(pw-totalW)/2;
var base = se('line');
sa(base,{x1:padL,y1:H-padB,x2:W-padR,y2:H-padB,class:'axis'});
svg.appendChild(base);
var gtop = se('line');
sa(gtop,{x1:padL,y1:padT,x2:W-padR,y2:padT,class:'axis minor'});
svg.appendChild(gtop);
var gl = se('text');
sa(gl,{x:padL-5,y:padT+3,'text-anchor':'end',class:'tick minor','font-size':fs-1});
gl.textContent = maxV;
svg.appendChild(gl);
var zl = se('text');
sa(zl,{x:padL-5,y:H-padB+3,'text-anchor':'end',class:'tick','font-size':fs-1});
zl.textContent = '0';
svg.appendChild(zl);
CATS.forEach(function(c,i){
var v = cur[i];
var bh = (v/maxV)*ph;
var x = startX+i*(bw+gap);
var y = H-padB-bh;
var rect = se('rect');
sa(rect,{x:x,y:y,width:bw,height:Math.max(bh,0.5),rx:4,ry:4,class:'bar'});
svg.appendChild(rect);
var lab = se('text');
sa(lab,{x:x+bw/2,y:Math.max(y-5,padT+fs),'text-anchor':'middle',class:'val','font-size':fs});
lab.textContent = Math.round(v);
svg.appendChild(lab);
var cat = se('text');
sa(cat,{x:x+bw/2,y:H-padB+14,'text-anchor':'middle',class:'tick','font-size':fs-1});
cat.textContent = c;
svg.appendChild(cat);
});
}
function animate(target){
var from = cur.slice();
var t0 = performance.now();
function step(t){
var p = Math.min(1,(t-t0)/650);
var e = 1-Math.pow(1-p,3);
cur = from.map(function(v,i){ return v+(target[i]-v)*e; });
draw();
if (p<1) requestAnimationFrame(step);
}
requestAnimationFrame(step);
}
new ResizeObserver(function(){ measure(); draw(); }).observe(svg);
measure();
draw();
animate(CATS.map(function(){ return R(28,96); }));
setInterval(function(){
animate(CATS.map(function(){ return R(15,98); }));
}, 3400);