function calcFF(){var short=document.getElementById("short").value||"1:05";var longdist=parseInt(document.getElementById("longdist").value)||800;var ff=parseFloat(document.getElementById("ff").value)||2;var p=short.split(":");var base=parseInt(p[0])*60+(parseInt(p[1])||0);var adj=base+ff;var pred=adj*(longdist/100);var pm=Math.floor(pred/60),ps=Math.round(pred%60);document.getElementById("r1").textContent=Math.floor(adj/60)+":"+String(Math.round(adj%60)).padStart(2,"0")+"/100m";document.getElementById("r2").textContent=pm+":"+String(ps).padStart(2,"0");document.getElementById("desc").innerHTML=""+longdist+"m predicted from "+short+"/100m short course pace with +"+ff+"s/100m fatigue factor:
Adjusted pace: "+Math.floor(adj/60)+":"+String(Math.round(adj%60)).padStart(2,"0")+"/100m
Predicted time: "+pm+":"+String(ps).padStart(2,"0")+"
Typical fatigue factors: 1-2s for elite, 3-5s for intermediate, 5-8s for beginners.";document.getElementById("results").style.display="block";}