// ─── FEED MATRIX ─────────────────────────────────────────────────────────────
const FEED_MATRIX = {
  wheat_straw:      {name:"Wheat Straw (Bhusa)",           dm:0.90,  cp:0.030, tdn:0.50,ndf:0.742,ca:0.0030, p:0.0010, cost:8,  cat:"Roughage",    maxWetKg:99},
  paddy_straw:      {name:"Paddy Straw",                   dm:0.90,  cp:0.046, tdn:0.60,ndf:0.662,ca:0.0025, p:0.0010, cost:8,  cat:"Roughage",    maxWetKg:99},
  cultivated_maize: {name:"Fresh Maize Fodder",            dm:0.22,  cp:0.082, tdn:0.78,ndf:0.525,ca:0.0042, p:0.0014, cost:7,  cat:"Green Cereal",maxWetKg:99},
  napier_grass:     {name:"Napier Grass (Mature)",         dm:0.22,  cp:0.092, tdn:0.58,ndf:0.717,ca:0.0030, p:0.0018, cost:5,  cat:"Green Cereal",maxWetKg:99},
  maize_silage:     {name:"Maize Silage",                  dm:0.30,  cp:0.079, tdn:0.68,ndf:0.460,ca:0.0042, p:0.0014, cost:8,  cat:"Silage",      maxWetKg:99},
  jowar_green:      {name:"Jowar Green Fodder",            dm:0.22,  cp:0.070, tdn:0.65,ndf:0.550,ca:0.0050, p:0.0020, cost:7,  cat:"Green Cereal",maxWetKg:99},
  berseem:          {name:"Berseem (Green Clover)",        dm:0.15,  cp:0.174, tdn:0.72,ndf:0.424,ca:0.0200, p:0.0038, cost:5,  cat:"Green Legume",maxWetKg:6.0},
  hmf:              {name:"Hydroponic Maize Fodder",       dm:0.2207,cp:0.1427,tdn:0.72,ndf:0.180,ca:0.00105,p:0.004129,cost:9, cat:"Hydroponic",  maxWetKg:99},
  commercial_feed:  {name:"Cattle Feed (BIS Type II)",     dm:0.90,  cp:0.200, tdn:0.72,ndf:0.300,ca:0.0070, p:0.0050, cost:28, cat:"Concentrate", maxWetKg:99},
  cottonseed_cake:  {name:"Cottonseed Cake (Binola Khali)",dm:0.90,  cp:0.410, tdn:0.70,ndf:0.280,ca:0.0017, p:0.0060, cost:22, cat:"Concentrate", maxWetKg:2.0},
  mustard_cake:     {name:"Mustard Cake (Sarson Khali)",   dm:0.90,  cp:0.380, tdn:0.72,ndf:0.256,ca:0.0073, p:0.0085, cost:32, cat:"Concentrate", maxWetKg:2.0},
  wheat_bran:       {name:"Wheat Bran (Chokar)",           dm:0.88,  cp:0.160, tdn:0.70,ndf:0.640,ca:0.0017, p:0.0093, cost:28, cat:"Concentrate", maxWetKg:3.0},
};
const FEEDS = Object.entries(FEED_MATRIX).map(([key,f])=>({
  key,name:f.name,dm:f.dm,cp:f.cp*100,tdn:f.tdn*100,ndf:f.ndf*100,
  ca:f.ca*100,p:f.p*100,cost:f.cost,cat:f.cat,maxWetKg:f.maxWetKg,
  desc:{
    wheat_straw:"Dry cereal straw, primary rumen mat. Low energy, essential for gut motility.",
    paddy_straw:"Rice straw, moderately high NDF. Good roughage base in paddy-growing regions.",
    cultivated_maize:"High-energy green fodder. Widely grown across India, good palatability.",
    napier_grass:"Pennisetum purpureum. High-yield perennial. Mature CP 9.2%, NDF 71.7%.",
    maize_silage:"Fermented maize, excellent energy and fibre balance. Year-round availability.",
    jowar_green:"Sorghum green fodder. Good calcium source. Common in Deccan and central India.",
    berseem:"Highest protein green fodder. Rich in Ca. Cap at 6 kg wet/day for palatability.",
    hmf:"HMF by Shunya Fodder & Forage Agritech. Lab-tested: 14.27% CP, 0.105% Ca, 0.413% P (SGS GG25-007509).",
    commercial_feed:"Compound cattle feed meeting BIS 1974 Type II norms. Balanced concentrate.",
    cottonseed_cake:"High protein oil cake. Max 2 kg/day wet. Avoid in late pregnancy (gossypol).",
    mustard_cake:"Rich in protein and phosphorus. High cost but excellent amino acid profile.",
    wheat_bran:"Excellent phosphorus source. Laxative effect at high doses. Max 3 kg/day.",
  }[key]||""
}));

const ASMM = {ca_pct:0.20, p_pct:0.12, cost_per_g:0.15};
const NDF_MIN = 0.28;

let customFeedCosts={};
Object.entries(FEED_MATRIX).forEach(([k,f])=>{customFeedCosts[k]=f.cost;});
customFeedCosts['asmm']=ASMM.cost_per_g;

const feedImages={
  wheat_straw:"https://www.shunya.live/wp-content/uploads/2026/05/Shunya-Agritech-Wheat-Straw-Bhusa.png",
  paddy_straw:"https://www.shunya.live/wp-content/uploads/2026/05/Shunya-Agritech-Paddy-Straw.jpeg",
  cultivated_maize:"https://www.shunya.live/wp-content/uploads/2026/05/Shunya-Agritech-Maize-Green-Forage.jpg",
  napier_grass:"https://www.shunya.live/wp-content/uploads/2026/05/Shunya-Agritech-hybrid-napier-bajra-grass.jpg",
  jowar_green:"https://www.shunya.live/wp-content/uploads/2026/05/Shunya-Agritech-Jowar-Green-Grass.jpeg",
  berseem:"https://www.shunya.live/wp-content/uploads/2026/05/Shunya-Agritech-Berseem-Barseem.jpg",
  maize_silage:"https://www.shunya.live/wp-content/uploads/2026/05/Shunya-Agritech-corn-silage-cattle-feed.jpg",
  hmf:"https://www.shunya.live/wp-content/uploads/2026/03/53d2a11b-f422-4b6b-b8fb-aa07e4ee8124-removebg-preview.png",
  commercial_feed:"https://www.shunya.live/wp-content/uploads/2026/05/Shunya-Agritech-Cattle-Feed.jpg",
  cottonseed_cake:"https://www.shunya.live/wp-content/uploads/2026/05/Shunya-Agritech-Cottonseed-Cake.jpg",
  mustard_cake:"https://www.shunya.live/wp-content/uploads/2026/05/Shunya-Agritech-Mustard-Cake.jpg",
  wheat_bran:"https://www.shunya.live/wp-content/uploads/2026/05/Shunya-Agritech-wheat-bran-for-animal-feed-663.jpg",
};

const SOURCES=[
  {title:"NDDB RBP — Feed Calculator Logic",desc:"Factorial method formulas, worked example",pdfUrl:"https://www.shunya.live/wp-content/uploads/2026/05/Feed-Calculator-Logic.pdf"},
  {title:"Animal Nutrition Booklet — NDDB 2012",desc:"Feed composition tables: CP, NDF, Ca, P",pdfUrl:"https://www.shunya.live/wp-content/uploads/2026/05/Animal-Nutrition-booklet-1.pdf"},
  {title:"FAO Paper 173 — Garg 2012",desc:"SARA limits — rumen acidity guidelines",pdfUrl:"https://www.shunya.live/wp-content/uploads/2026/05/i3014e00.pdf"},
  {title:"NDDB Compound Cattle Feed Norm",desc:"Daily cattle feed norms by body weight",pdfUrl:"https://www.shunya.live/wp-content/uploads/2026/05/Compound_Cattle_Feed1.pdf"},
  {title:"ICAR 2013 Nutrient Requirements",desc:"Indian standard nutrient requirement tables",pdfUrl:"https://www.shunya.live/wp-content/uploads/2026/05/Mineral_Mixture1.pdf"},
  {title:"SGS India Lab Report GG25-007509",desc:"HMF composition: protein, Ca, P by Shunya Fodder",pdfUrl:"https://www.shunya.live/wp-content/uploads/2026/05/Report_maize-8aug-1.pdf"},
];
const CAT_GROUPS=[
  {label:"Dry Roughage",cats:["Roughage"]},
  {label:"Green Fodder",cats:["Green Cereal","Green Legume"]},
  {label:"Silage",cats:["Silage"]},
  {label:"Hydroponic",cats:["Hydroponic"]},
  {label:"Concentrates",cats:["Concentrate"]},
];

let baselineChecked={}, customQtyMap={}, customLockMap={}, milkPricePerLitre=null;
let goalsState=null, baselineResult=null, customResult=null;

// ─── GOALS ───────────────────────────────────────────────────────────────────
function computeGoals(){
  const animalType=document.getElementById('animalType').value;
  const lifeStage=document.getElementById('lifeStage').value;
  const bw=parseFloat(document.getElementById('bodyWeight').value)||450;
  const milk=lifeStage==='lactating'?parseFloat(document.getElementById('milkYield').value)||0:0;
  const fat=lifeStage==='lactating'?parseFloat(document.getElementById('fatPct').value)||4.0:0;
  const mbw=Math.pow(bw,0.75);
  let dmiTarget,dmiMax,tdnTargetG,cpTargetG,caTargetG,pTargetG;
  if(lifeStage==='calf'){
    dmiTarget=dmiMax=bw*0.022; tdnTargetG=bw*12; cpTargetG=bw*4.5;
    caTargetG=bw*0.35; pTargetG=bw*0.20;
  } else if(lifeStage==='pregnant_t1'){
    dmiTarget=dmiMax=bw*0.020; tdnTargetG=35*mbw; cpTargetG=5.0*mbw;
    caTargetG=(animalType==='buffalo'?4.5:4.0)*bw/100; pTargetG=2.0*bw/100;
  } else if(lifeStage==='pregnant_t2'){
    dmiTarget=dmiMax=bw*0.020; tdnTargetG=35*mbw+700; cpTargetG=5.0*mbw+75;
    caTargetG=(animalType==='buffalo'?4.5:4.0)*bw/100+5; pTargetG=2.0*bw/100+3;
  } else if(lifeStage==='pregnant_t3'){
    dmiTarget=dmiMax=bw*0.020; tdnTargetG=35*mbw+1500; cpTargetG=5.0*mbw+150;
    caTargetG=(animalType==='buffalo'?4.5:4.0)*bw/100+11; pTargetG=2.0*bw/100+6.5;
  } else if(lifeStage==='dry'){
    dmiTarget=dmiMax=bw*0.018; tdnTargetG=35*mbw; cpTargetG=5.0*mbw;
    caTargetG=(animalType==='buffalo'?4.5:4.0)*bw/100; pTargetG=2.0*bw/100;
  } else {
    if(animalType==='buffalo'){
      const fcm6=milk*(0.4+0.15*fat)/1.3;
      tdnTargetG=37*mbw+368*fcm6; cpTargetG=5.2*mbw+76*fcm6;
      caTargetG=4.5*bw/100+3.2*milk; pTargetG=2.0*bw/100+2.6*milk;
      dmiTarget=bw*0.025+milk*0.075; dmiMax=bw*0.025+milk*0.15;
    } else if(animalType==='cow_indigenous'){
      const fcm4=milk*(0.4+0.15*fat);
      tdnTargetG=35*mbw+236*fcm4; cpTargetG=5.0*mbw+57*fcm4;
      caTargetG=4.0*bw/100+2.8*milk; pTargetG=2.0*bw/100+2.2*milk;
      dmiTarget=bw*0.022+milk*0.140; dmiMax=bw*0.022+milk*0.200;
    } else {
      const fcm4=milk*(0.4+0.15*fat);
      tdnTargetG=35*mbw+298*fcm4; cpTargetG=5.0*mbw+63*fcm4;
      caTargetG=4.0*bw/100+2.4*milk; pTargetG=2.0*bw/100+1.9*milk;
      dmiTarget=bw*0.025+milk*0.025; dmiMax=bw*0.025+milk*0.10;
    }
  }
  return {bw,milk,fat,animalType,lifeStage,mbw,dmiTarget,dmiMax,tdnTargetG,cpTargetG,caTargetG,pTargetG};
}

function computeAsmm(caFeedD,pFeedD,caTarget,pTarget,bw){
  const ca_gap=Math.max(0,caTarget-caFeedD);
  const p_gap=Math.max(0,pTarget-pFeedD);
  if(ca_gap<=0&&p_gap<=0) return {dose_g:0,ca:0,p:0,ca_gap:0,p_gap:0,caDriver:'none'};
  const doseRaw=Math.max(ca_gap/ASMM.ca_pct, p_gap/ASMM.p_pct);
  const dynamicCeiling=bw?Math.min(300,bw*0.4):200;
  const dose_g=Math.min(dynamicCeiling,Math.ceil(doseRaw/10)*10);
  const caDriver=(ca_gap/ASMM.ca_pct)>=(p_gap/ASMM.p_pct)?'Ca':'P';
  return {dose_g,ca:dose_g*ASMM.ca_pct,p:dose_g*ASMM.p_pct,ca_gap,p_gap,caDriver};
}

function runSolverCore(goals,lockedOverrides,checkedKeys){
  const{dmiTarget,dmiMax,tdnTargetG,cpTargetG,bw,milk,lifeStage}=goals;
  const AF={};
  for(const key of(checkedKeys||Object.keys(FEED_MATRIX))){
    const fm=FEED_MATRIX[key];if(!fm)continue;
    const isLocked=!!(lockedOverrides&&lockedOverrides[key]!==undefined);
    AF[key]={...fm,isLocked,forcedWet:isLocked?lockedOverrides[key]:0};
  }
  let schedule={},dmiD=0,tdnD=0,cpD=0,ndfD=0,caFeedD=0,pFeedD=0;
  function add(key,wet){
    if(wet<=0||!AF[key])return false;
    const f=AF[key];const dm=wet*f.dm;
    if(dmiD+dm>dmiMax*1.001)return false;
    if((schedule[key]||0)+wet>(f.maxWetKg||99)*1.001)return false;
    schedule[key]=(schedule[key]||0)+wet;
    dmiD+=dm;tdnD+=dm*f.tdn*1000;cpD+=dm*f.cp*1000;
    ndfD+=dm*f.ndf;caFeedD+=dm*f.ca*1000;pFeedD+=dm*f.p*1000;
    return true;
  }
  const freeOf=cat=>Object.keys(AF).filter(k=>!AF[k].isLocked&&AF[k].cat===cat);
  const freeConc=()=>freeOf('Concentrate');
  for(const k in AF){
    if(!AF[k].isLocked)continue;
    const wet=AF[k].forcedWet;
    const allowed=Math.min(wet,Math.max(0,(dmiMax-dmiD)/AF[k].dm));
    if(allowed>0.001){
      schedule[k]=(schedule[k]||0)+allowed;
      const d=allowed*AF[k].dm;
      dmiD+=d;tdnD+=d*AF[k].tdn*1000;cpD+=d*AF[k].cp*1000;
      ndfD+=d*AF[k].ndf;caFeedD+=d*AF[k].ca*1000;pFeedD+=d*AF[k].p*1000;
    }
  }
  const roughFloorDm=(lifeStage==='calf'?bw*0.0045:bw*0.009);
  const alreadyRoughDm=Object.keys(AF).filter(k=>AF[k].isLocked&&AF[k].cat==='Roughage').reduce((s,k)=>s+AF[k].forcedWet*AF[k].dm,0);
  const roughNeedDm=Math.max(0,roughFloorDm-alreadyRoughDm);
  const fr=freeOf('Roughage').sort((a,b)=>AF[a].cost-AF[b].cost);
  if(fr.length>0&&roughNeedDm>0.05){
    if(fr.length===1)add(fr[0],roughNeedDm/AF[fr[0]].dm);
    else{add(fr[0],roughNeedDm*0.70/AF[fr[0]].dm);add(fr[1],roughNeedDm*0.30/AF[fr[1]].dm);}
  }
  const roughTdnEst=bw*0.009*(0.70*0.50+0.30*0.60)*1000;
  const maxGreenTdn=Math.max(0,tdnTargetG*0.68-roughTdnEst);
  const greenTdnPerKg=0.80*0.22*0.78*1000+0.20*0.15*0.72*1000;
  const fullGBbyTDN=maxGreenTdn/greenTdnPerKg;
  const fullGB=Math.min(bw*0.030+milk*0.50,dmiTarget*1.2,fullGBbyTDN);
  const gCereals=[...freeOf('Green Cereal'),...freeOf('Silage')].sort((a,b)=>(AF[b].tdn-AF[a].tdn)||(AF[a].cost-AF[b].cost));
  const gLegumes=freeOf('Green Legume').sort((a,b)=>AF[a].cost-AF[b].cost);
  if(gCereals.length>0&&gLegumes.length>0){add(gCereals[0],fullGB*0.80);add(gLegumes[0],fullGB*0.20);}
  else if(gCereals.length>0){add(gCereals[0],fullGB);}
  else if(gLegumes.length>0){add(gLegumes[0],Math.min(fullGB*0.50,AF[gLegumes[0]].maxWetKg||99));}
  const freeHmf=freeOf('Hydroponic');
  if(freeHmf.length>0&&gCereals.length===0){add(freeHmf[0],fullGB*0.80);}
  const concNormWet=lifeStage==='calf'?0:(2.75+milk*0.4);
  const concNormDmCeil=lifeStage==='calf'?dmiMax*0.30:concNormWet*0.92;
  const concPool=freeConc();
  const cappedC=concPool.filter(k=>(AF[k].maxWetKg||99)<=10);
  const sumCap=cappedC.reduce((s,k)=>s+(AF[k].maxWetKg||99)*AF[k].dm,0);
  const lockedConcDm=Object.keys(AF).filter(k=>AF[k].isLocked&&AF[k].cat==='Concentrate').reduce((s,k)=>s+AF[k].forcedWet*AF[k].dm,0);
  const freeDmHR=Math.max(0,concNormDmCeil-lockedConcDm);
  const cScale=(sumCap>0&&freeDmHR<sumCap)?freeDmHR/sumCap:1.0;
  const effMax=k=>(AF[k].maxWetKg||99)<=10?(AF[k].maxWetKg||99)*cScale:(AF[k].maxWetKg||99);
  for(let i=0;i<2000;i++){
    const remTdn=tdnTargetG-tdnD,remCp=cpTargetG-cpD;
    if(remTdn<=tdnTargetG*0.01&&remCp<=cpTargetG*0.01)break;
    if(dmiD>=dmiMax*0.999)break;
    const cDm=Object.keys(schedule).reduce((s,k)=>FEED_MATRIX[k]?.cat==='Concentrate'?s+(schedule[k]||0)*FEED_MATRIX[k].dm:s,0);
    if(concNormDmCeil>0&&cDm>=concNormDmCeil*0.99)break;
    if(cpD>cpTargetG*1.30)break;
    if(tdnD>tdnTargetG*1.05)break;
    const cpCeil=cpD>cpTargetG*1.15;
    const eligPool=cpCeil?concPool.filter(k=>AF[k]).sort((a,b)=>AF[a].cp-AF[b].cp):concPool;
    const elig=eligPool.filter(k=>AF[k]&&(schedule[k]||0)<effMax(k)*0.99);
    if(!elig.length)break;
    const tot=Math.max(1,Math.max(0,remTdn)+Math.max(0,remCp));
    const best=elig.reduce((b,k)=>{
      const f=AF[k];const s=(Math.max(0,remTdn)/tot*f.tdn*f.dm*1000+Math.max(0,remCp)/tot*f.cp*f.dm*1000)/f.cost;
      return s>b.score?{key:k,score:s}:b;
    },{key:null,score:-1}).key;
    if(!best)break;
    const micro=Math.min(0.04,(dmiMax-dmiD)*0.4,(effMax(best)-(schedule[best]||0))*AF[best].dm)/AF[best].dm;
    if(micro<=0||!add(best,micro))break;
  }
  if(tdnD<tdnTargetG*0.99&&cpD>cpTargetG*1.15){
    const highCpConc=freeConc().filter(k=>AF[k].cp>0.25&&(schedule[k]||0)>0.1).sort((a,b)=>AF[b].cp-AF[a].cp);
    const lowCpConc=freeConc().filter(k=>AF[k].cp<=0.25).sort((a,b)=>AF[a].cost-AF[b].cost);
    for(const hk of highCpConc){
      for(const lk of lowCpConc){
        let go=true;
        while(go){
          go=false;
          if((schedule[hk]||0)<0.11||tdnD>=tdnTargetG*0.99||cpD<=cpTargetG*1.05)break;
          const swapDm=0.1*AF[hk].dm,addWet=swapDm/AF[lk].dm;
          if((schedule[lk]||0)+addWet>effMax(lk)*1.001)break;
          const nT=tdnD-swapDm*AF[hk].tdn*1000+swapDm*AF[lk].tdn*1000;
          const nC=cpD-swapDm*AF[hk].cp*1000+swapDm*AF[lk].cp*1000;
          if(nC<=cpTargetG*1.40){
            schedule[hk]=(schedule[hk]||0)-0.1;if(schedule[hk]<0.01)delete schedule[hk];
            schedule[lk]=(schedule[lk]||0)+addWet;tdnD=nT;cpD=nC;go=true;
          }
        }
      }
    }
    const lowPool=freeConc().sort((a,b)=>AF[a].cp-AF[b].cp);
    for(const k of lowPool){
      for(let i=0;i<500;i++){
        if(tdnD>=tdnTargetG*0.99||dmiD>=dmiMax*0.999)break;
        if(cpD>cpTargetG*1.30)break;
        const cDm=Object.keys(schedule).reduce((s,j)=>FEED_MATRIX[j]?.cat==='Concentrate'?s+(schedule[j]||0)*FEED_MATRIX[j].dm:s,0);
        if(concNormDmCeil>0&&cDm>=concNormDmCeil*0.99)break;
        const micro=Math.min(0.04,(dmiMax-dmiD)*0.4,(effMax(k)-(schedule[k]||0))*AF[k].dm)/AF[k].dm;
        if(micro<=0||!add(k,micro))break;
      }
      if(tdnD>=tdnTargetG*0.99)break;
    }
  }
  if(dmiD<dmiTarget*0.97&&fr.length>0){
    const k=fr[0],gap=dmiTarget-dmiD;
    const maxByTdn=tdnTargetG*1.10>tdnD?Math.max(0,(tdnTargetG*1.10-tdnD)/(AF[k].tdn*1000*AF[k].dm)):0;
    const allowed=Math.min(gap/AF[k].dm,(dmiMax-dmiD)/AF[k].dm,maxByTdn/AF[k].dm);
    if(allowed>0.1)add(k,allowed);
  }
  if(tdnD<tdnTargetG*0.99&&cpD<cpTargetG*0.99&&dmiD<dmiMax*0.99){
    const tdnPool=freeConc().sort((a,b)=>AF[a].cost-AF[b].cost);
    for(const k of tdnPool){
      for(let i=0;i<600;i++){
        if(tdnD>=tdnTargetG*0.99||cpD>=cpTargetG*1.30||dmiD>=dmiMax*0.999)break;
        const micro=Math.min(0.1,(dmiMax-dmiD)/AF[k].dm,(AF[k].maxWetKg||99)-(schedule[k]||0));
        if(micro<=0||!add(k,micro))break;
      }
      if(tdnD>=tdnTargetG*0.99)break;
    }
  }
  if(dmiD>0.1&&(ndfD/dmiD)<NDF_MIN){
    const hNdf=freeOf('Roughage').sort((a,b)=>AF[b].ndf-AF[a].ndf);
    for(const k of hNdf){
      const need=dmiD*NDF_MIN-ndfD;if(need<=0)break;
      const wet=Math.min(need/AF[k].ndf/AF[k].dm,(dmiMax-dmiD)/AF[k].dm);
      if(wet>0.05)add(k,wet);
    }
  }
  if(goals._costMinimise){
    const baselineCaps=goals._baselineCaps||null;
    if(baselineCaps&&fr.length>0){
      const capCats=new Set(['Green Cereal','Silage','Green Legume','Concentrate']);
      const cheapRK=fr[0];
      for(const k of Object.keys(schedule)){
        if(!AF[k]||!capCats.has(AF[k].cat)||AF[k].isLocked)continue;
        const baseCap=baselineCaps[k];if(baseCap===undefined)continue;
        const excess=(schedule[k]||0)-baseCap;if(excess<0.05)continue;
        const trimDm=excess*AF[k].dm;
        schedule[k]=baseCap;if(schedule[k]<0.01)delete schedule[k];
        dmiD-=trimDm;tdnD-=trimDm*AF[k].tdn*1000;cpD-=trimDm*AF[k].cp*1000;
        ndfD-=trimDm*AF[k].ndf;caFeedD-=trimDm*AF[k].ca*1000;pFeedD-=trimDm*AF[k].p*1000;
        if(cheapRK){
          const repWet=Math.min(trimDm/AF[cheapRK].dm,(dmiMax-dmiD)/AF[cheapRK].dm);
          if(repWet>0.01){
            schedule[cheapRK]=(schedule[cheapRK]||0)+repWet;
            const repDm=repWet*AF[cheapRK].dm;
            dmiD+=repDm;tdnD+=repDm*AF[cheapRK].tdn*1000;cpD+=repDm*AF[cheapRK].cp*1000;
            ndfD+=repDm*AF[cheapRK].ndf;caFeedD+=repDm*AF[cheapRK].ca*1000;pFeedD+=repDm*AF[cheapRK].p*1000;
          }
        }
      }
    }
    const hmfTdnNow=Object.keys(schedule).filter(k=>AF[k]?.cat==='Hydroponic'&&AF[k].isLocked).reduce((s,k)=>(schedule[k]||0)*AF[k].dm*AF[k].tdn*1000+s,0);
    const hasLockedHmf=hmfTdnNow>0;
    if(!hasLockedHmf){
      const TDN_FL=tdnTargetG*0.99,CP_FL=cpTargetG*0.99,cheapRK=fr[0];
      if(tdnD>tdnTargetG*1.02){
        const greenCands=Object.keys(schedule).filter(k=>!AF[k]?.isLocked&&(AF[k]?.cat==='Green Cereal'||AF[k]?.cat==='Silage')&&(schedule[k]||0)>0.11).sort((a,b)=>(AF[b]?.tdn||0)-(AF[a]?.tdn||0));
        for(const k of greenCands){
          let go=true;
          while(go){
            go=false;const cur=schedule[k]||0;if(cur<0.11)break;
            const f=AF[k],tDm=0.1*f.dm,rf=cheapRK?AF[cheapRK]:null;
            const repDm=rf?tDm:0,repWet=rf?repDm/rf.dm:0;
            if(rf&&(dmiD-tDm+repDm)>dmiMax*1.001)break;
            const nT=tdnD-tDm*f.tdn*1000+(rf?repDm*rf.tdn*1000:0);
            const nC=cpD-tDm*f.cp*1000+(rf?repDm*rf.cp*1000:0);
            const nN=ndfD-tDm*f.ndf+(rf?repDm*rf.ndf:0);
            const nD=dmiD-tDm+repDm;
            if(nT>=TDN_FL&&nC>=cpTargetG*0.85&&nD>0){
              schedule[k]=cur-0.1;if(schedule[k]<0.01)delete schedule[k];
              dmiD=nD;tdnD=nT;cpD=nC;ndfD=nN;
              if(rf&&repWet>0){schedule[cheapRK]=(schedule[cheapRK]||0)+repWet;caFeedD+=repDm*rf.ca*1000-tDm*f.ca*1000;pFeedD+=repDm*rf.p*1000-tDm*f.p*1000;}
              else{caFeedD-=tDm*f.ca*1000;pFeedD-=tDm*f.p*1000;}
              go=true;
            }
          }
          if(tdnD<=tdnTargetG*1.02)break;
        }
      }
      if(tdnD>tdnTargetG*1.02||cpD>cpTargetG*1.30){
        const concCands=Object.keys(schedule).filter(k=>!AF[k]?.isLocked&&AF[k]?.cat==='Concentrate'&&(schedule[k]||0)>0.11).sort((a,b)=>(AF[b]?.cost||0)-(AF[a]?.cost||0));
        for(const k of concCands){
          let go=true;
          while(go){
            go=false;const cur=schedule[k]||0;if(cur<0.11)break;
            const f=AF[k],tDm=0.1*f.dm;
            const nT=tdnD-tDm*f.tdn*1000,nC=cpD-tDm*f.cp*1000,nD=dmiD-tDm,nN=ndfD-tDm*f.ndf;
            if(nT>=TDN_FL&&nC>=CP_FL&&nD>=dmiTarget*0.95){
              schedule[k]=cur-0.1;if(schedule[k]<0.01)delete schedule[k];
              dmiD=nD;tdnD=nT;cpD=nC;ndfD=nN;caFeedD-=tDm*f.ca*1000;pFeedD-=tDm*f.p*1000;go=true;
            }
          }
        }
      }
      if(dmiD<dmiTarget*0.99&&fr.length>0){
        const k=fr[0],gap=dmiTarget-dmiD;
        const fw=Math.min(gap/AF[k].dm,(dmiMax-dmiD)/AF[k].dm);
        if(fw>0.05){
          schedule[k]=(schedule[k]||0)+fw;const ad=fw*AF[k].dm;
          dmiD+=ad;tdnD+=ad*AF[k].tdn*1000;cpD+=ad*AF[k].cp*1000;
          ndfD+=ad*AF[k].ndf;caFeedD+=ad*AF[k].ca*1000;pFeedD+=ad*AF[k].p*1000;
        }
      }
    }else{
      const TDN_FL=tdnTargetG*0.99,CP_FL=cpTargetG*0.99,cheapRK=fr[0];
      const TRIM_CATS=new Set(['Concentrate','Hydroponic']);
      const trimCands=Object.keys(schedule).filter(k=>!AF[k]?.isLocked&&TRIM_CATS.has(AF[k]?.cat)&&(schedule[k]||0)>0.11).sort((a,b)=>(AF[b]?.cost||0)-(AF[a]?.cost||0));
      for(const k of trimCands){
        let go=true;
        while(go){
          go=false;const cur=schedule[k]||0;if(cur<0.11)break;
          const f=AF[k],tDm=0.1*f.dm,rf=cheapRK?AF[cheapRK]:null;
          const repDm=rf?tDm:0,repWet=rf?repDm/rf.dm:0;
          if(rf&&(dmiD-tDm+repDm)>dmiMax*1.001)break;
          const nT=tdnD-tDm*f.tdn*1000+(rf?repDm*rf.tdn*1000:0);
          const nC=cpD-tDm*f.cp*1000+(rf?repDm*rf.cp*1000:0);
          const nN=ndfD-tDm*f.ndf+(rf?repDm*rf.ndf:0);
          const nD=dmiD-tDm+repDm;
          const ndfOk=nD<0.1||(nN/nD)>=NDF_MIN;
          if(nT>=TDN_FL&&nC>=CP_FL&&ndfOk&&nD>0){
            schedule[k]=cur-0.1;if(schedule[k]<0.01)delete schedule[k];
            dmiD=nD;tdnD=nT;cpD=nC;ndfD=nN;
            if(rf&&repWet>0){schedule[cheapRK]=(schedule[cheapRK]||0)+repWet;caFeedD+=repDm*rf.ca*1000-tDm*f.ca*1000;pFeedD+=repDm*rf.p*1000-tDm*f.p*1000;}
            else{caFeedD-=tDm*f.ca*1000;pFeedD-=tDm*f.p*1000;}
            go=true;
          }
        }
      }
      if((tdnD<tdnTargetG*0.99||cpD<cpTargetG*0.99)&&dmiD<dmiMax*0.99){
        const rec=freeConc().sort((a,b)=>AF[a].cost-AF[b].cost);
        for(const k of rec){
          for(let i=0;i<500;i++){
            if(tdnD>=tdnTargetG*0.99&&cpD>=cpTargetG*0.99)break;
            if(dmiD>=dmiMax*0.999)break;
            const m=Math.min(0.1,(dmiMax-dmiD)/AF[k].dm,(AF[k].maxWetKg||99)-(schedule[k]||0));
            if(m<=0||!add(k,m))break;
          }
          if(tdnD>=tdnTargetG*0.99&&cpD>=cpTargetG*0.99)break;
        }
      }
    }
  }
  return{schedule,dmiD,tdnD,cpD,ndfD,caFeedD,pFeedD};
}

// ─── MODALS ──────────────────────────────────────────────────────────────────
function openModal(id){document.getElementById(id).classList.add('open');}
function closeModal(id){document.getElementById(id).classList.remove('open');}
// modal overlay click-to-close
document.querySelectorAll('.modal-overlay').forEach(el=>el.addEventListener('click',function(e){if(e.target===this)closeModal(this.id);}));
function buildSources(){
  document.getElementById('sourcesList').innerHTML=SOURCES.map(s=>`
    <div class="source-item">
      <div class="source-info"><div class="source-title">${s.title}</div><div class="source-desc">${s.desc}</div></div>
      ${s.pdfUrl?`<a class="source-pdf-btn" href="${s.pdfUrl}" target="_blank">PDF</a>`:`<button class="source-pdf-btn placeholder-btn" disabled>PDF</button>`}
    </div>`).join('');
}
function openFeedInfo(feedKey){
  const f=FEEDS.find(x=>x.key===feedKey);
  document.getElementById('infoModalTitle').textContent=f.name;
  document.getElementById('infoNutrientChips').innerHTML=[
    `<span class="chip chip-dm">DM ${(f.dm*100).toFixed(0)}%</span>`,
    `<span class="chip chip-cp">CP ${f.cp.toFixed(1)}%</span>`,
    `<span class="chip chip-tdn">TDN ${f.tdn.toFixed(1)}%</span>`,
    `<span class="chip chip-ndf">NDF ${f.ndf.toFixed(1)}%</span>`,
    `<span class="chip chip-ca">Ca ${f.ca.toFixed(2)}%</span>`,
    `<span class="chip chip-p">P ${f.p.toFixed(2)}%</span>`,
    `<span class="chip chip-cost">&#8377;${f.cost}/kg</span>`,
  ].join('');
  document.getElementById('infoDesc').textContent=f.desc;
  const ph=document.getElementById('infoImgPlaceholder');
  ph.innerHTML=feedImages[feedKey]?`<img src="${feedImages[feedKey]}">`:`<span style="font-size:12px;color:var(--gray-400)">No image available</span>`;
  openModal('infoModal');
}
function expandFeedImage(el){
  const img=el.querySelector('img');if(!img)return;
  const ov=document.createElement('div');
  ov.style.cssText='position:fixed;inset:0;background:rgba(0,0,0,0.85);z-index:99999;display:flex;align-items:center;justify-content:center;cursor:zoom-out';
  const bi=document.createElement('img');bi.src=img.src;
  bi.style.cssText='max-width:92vw;max-height:88vh;border-radius:8px';
  ov.appendChild(bi);ov.addEventListener('click',()=>ov.remove());document.body.appendChild(ov);
}

// ─── STEP FLOW ───────────────────────────────────────────────────────────────
function toggleStep(id){document.getElementById(id).classList.toggle('collapsed');}
function openStep(id){
  const el=document.getElementById(id);el.classList.remove('hidden','collapsed');
  setTimeout(()=>{try{el.scrollIntoView({behavior:'smooth',block:'start'});}catch(e){}},100);
}
function collapseStep(id){document.getElementById(id).classList.add('collapsed');}
function onLifeStageChange(){
  const ls=document.getElementById('lifeStage').value;
  document.getElementById('milkField').style.display=ls==='lactating'?'':'none';
  document.getElementById('fatField').style.display=ls==='lactating'?'':'none';
}
document.getElementById('animalType').addEventListener('change',function(){
  const fi=document.getElementById('fatPct');if(!fi)return;
  if(this.value==='cow_indigenous')fi.value=4.5;
  else if(this.value==='cow_crossbred')fi.value=3.5;
  updateBreedNote();
});
function updateBreedNote(){
  const el=document.getElementById('breedNote');if(!el)return;
  const v=document.getElementById('animalType').value;
  el.textContent=v==='cow_indigenous'
    ?'DMI adjusted downward (BW×2.2% + milk×2.5%) — reflects lower voluntary intake of Gir / Kankrej / Sahiwal. Same TDN, CP, Ca, P coefficients as crossbred per ICAR 2013.'
    :v==='buffalo'
    ?'DMI: BW×2.5% + milk×2.5% · Buffalo-specific TDN and Ca/P coefficients'
    :'DMI: BW×2.5% + milk×2.5% · Nutrient coefficients: ICAR 2013 standard';
}
function confirmAnimalDetails(){
  goalsState=computeGoals();
  document.getElementById('step1Num').classList.add('done');
  collapseStep('step1Section');renderStep2();openStep('step2Section');
}
function renderStep2(){
  const g=goalsState;
  document.getElementById('goalsRow').innerHTML=[
    {label:'DMI',val:g.dmiTarget.toFixed(1),unit:'kg/day'},
    {label:'TDN',val:(g.tdnTargetG/1000).toFixed(2),unit:'kg/day'},
    {label:'CP',val:g.cpTargetG.toFixed(0),unit:'g/day'},
    {label:'NDF',val:'≥28%',unit:'of DM'},
    {label:'Ca',val:g.caTargetG.toFixed(1),unit:'g/day'},
    {label:'P',val:g.pTargetG.toFixed(1),unit:'g/day'},
  ].map(d=>`<div class="goal-card"><div class="goal-label">${d.label}</div><div class="goal-value">${d.val}</div><div class="goal-unit">${d.unit}</div></div>`).join('');
  FEEDS.forEach(f=>{if(baselineChecked[f.key]===undefined)baselineChecked[f.key]=true;});
}
function openStep22(){
  document.getElementById('step2Num').classList.add('done');
  collapseStep('step2Section');renderFeedSelectList();openStep('step22Section');
}
function renderFeedSelectList(){
  const bc={'Roughage':'cat-roughage','Green Cereal':'cat-green','Green Legume':'cat-green','Silage':'cat-silage','Hydroponic':'cat-hydro','Concentrate':'cat-conc'};
  let html='';
  CAT_GROUPS.forEach(grp=>{
    const feeds=FEEDS.filter(f=>grp.cats.includes(f.cat));if(!feeds.length)return;
    html+=`<div class="feed-section-title">${grp.label}</div><div class="feed-grid">`;
    feeds.forEach(f=>{
      const checked=baselineChecked[f.key]!==false;
      html+=`<div class="feed-row${checked?' checked':''}" id="feedrow_${f.key}">
        <input type="checkbox" ${checked?'checked':''} onchange="toggleFeedCheck('${f.key}',this.checked)" id="chk_${f.key}">
        <div class="feed-name-wrap"><label for="chk_${f.key}" class="feed-name" title="${f.name}">${f.name}</label><button class="feed-info-btn" onclick="openFeedInfo('${f.key}')">i</button></div>
        <span class="feed-cat-badge ${bc[f.cat]||'cat-conc'}">${f.cat}</span>
      </div>`;
    });
    html+=`</div>`;
  });
  document.getElementById('feedSelectList').innerHTML=html;
}
function toggleFeedCheck(key,val){
  baselineChecked[key]=val;
  const row=document.getElementById('feedrow_'+key);
  if(row){val?row.classList.add('checked'):row.classList.remove('checked');}
}
function calculateBaseline(){
  const checked=FEEDS.filter(f=>baselineChecked[f.key]!==false).map(f=>f.key);
  const res=runSolverCore({...goalsState,_costMinimise:true},{},checked);
  const asmm=computeAsmm(res.caFeedD,res.pFeedD,goalsState.caTargetG,goalsState.pTargetG,goalsState.bw);
  baselineResult={...res,asmm,goals:goalsState,checked};
  document.getElementById('step22Num').classList.add('done');
  collapseStep('step22Section');renderDietSection('baseline',res,asmm,goalsState);openStep('step3Section');
}
function calcRationCost(schedule,dose_g){
  let cost=0;
  FEEDS.forEach(f=>{cost+=(schedule[f.key]||0)*(customFeedCosts[f.key]||f.cost);});
  cost+=dose_g*(customFeedCosts['asmm']||ASMM.cost_per_g);
  return cost;
}
function buildAlerts(res,asmm,goals){
  const alerts=[];
  const ndfPct=res.dmiD>0?res.ndfD/res.dmiD*100:0;
  const totalCaG=res.caFeedD+asmm.ca,totalPG=res.pFeedD+asmm.p;
  const concDmPct=(()=>{
    const cd=Object.keys(res.schedule).reduce((s,k)=>{
      const cat=FEED_MATRIX[k]?.cat,dm=(res.schedule[k]||0)*FEED_MATRIX[k].dm;
      return cat==='Concentrate'?s+dm:s;
    },0);
    return res.dmiD>0?cd/res.dmiD*100:0;
  })();
  const milk=goals.milk||0,ls=goals.lifeStage;
  const isNonLac=(ls==='pregnant_t1'||ls==='pregnant_t2'||ls==='pregnant_t3'||ls==='dry'||ls==='calf');
  const saraLim=isNonLac?30:milk<=5?40:milk<=10?50:milk<=15?60:70;
  const hasAnyGreen=Object.keys(res.schedule).some(k=>(res.schedule[k]||0)>0.1&&['Green Cereal','Silage','Green Legume','Hydroponic'].includes(FEED_MATRIX[k]?.cat));
  if(!hasAnyGreen&&goals.lifeStage==='lactating')alerts.push(`<div class="alert-item alert-warn"><div class="alert-text"><strong>No Green Fodder in Diet</strong>Add maize fodder, jowar, napier, silage, berseem, or HMF to meet energy targets within SARA-safe limits.</div></div>`);
  if(res.dmiD>goals.dmiMax*1.01)alerts.push(`<div class="alert-item alert-error"><div class="alert-text"><strong>Stomach Overfill Risk</strong>DMI ${res.dmiD.toFixed(2)} kg exceeds max ${goals.dmiMax.toFixed(2)} kg.</div></div>`);
  if(concDmPct>saraLim)alerts.push(`<div class="alert-item alert-warn"><div class="alert-text"><strong>Rumen Acidity Risk (SARA)</strong>Concentrate DM ${concDmPct.toFixed(1)}% exceeds safe limit ${saraLim}% for current yield.</div></div>`);
  if(ndfPct<28)alerts.push(`<div class="alert-item alert-warn"><div class="alert-text"><strong>Low Fibre (NDF)</strong>NDF ${ndfPct.toFixed(1)}% is below recommended 28%. Add more roughage.</div></div>`);
  if(res.tdnD<goals.tdnTargetG*0.97&&res.dmiD>=goals.dmiMax*0.98)alerts.push(`<div class="alert-item alert-error"><div class="alert-text"><strong>Energy Gap — Feed Quality Constraint</strong>TDN target cannot be met within stomach capacity. Consider higher-energy feeds.</div></div>`);
  if(totalCaG<goals.caTargetG*0.90)alerts.push(`<div class="alert-item alert-error"><div class="alert-text"><strong>Calcium Shortfall</strong>Total Ca ${totalCaG.toFixed(1)}g below 90% of target ${goals.caTargetG.toFixed(1)}g.</div></div>`);
  if(totalPG<goals.pTargetG*0.90)alerts.push(`<div class="alert-item alert-error"><div class="alert-text"><strong>Phosphorus Shortfall</strong>Total P ${totalPG.toFixed(1)}g below 90% of target ${goals.pTargetG.toFixed(1)}g.</div></div>`);
  if(res.tdnD<goals.tdnTargetG*0.97&&res.dmiD<goals.dmiMax*0.98)alerts.push(`<div class="alert-item alert-warn"><div class="alert-text"><strong>Energy Shortfall</strong>TDN ${(res.tdnD/1000).toFixed(2)}kg vs target ${(goals.tdnTargetG/1000).toFixed(2)}kg.</div></div>`);
  if(res.cpD>goals.cpTargetG*1.35)alerts.push(`<div class="alert-item alert-warn"><div class="alert-text"><strong>Excess Protein Warning</strong>CP ${res.cpD.toFixed(0)}g exceeds 135% of target. Risk of liver urea strain and wasted feed cost.</div></div>`);
  if(res.cpD<goals.cpTargetG*0.95)alerts.push(`<div class="alert-item alert-warn"><div class="alert-text"><strong>Protein Shortfall</strong>CP ${res.cpD.toFixed(0)}g vs target ${goals.cpTargetG.toFixed(0)}g. Add mustard/cottonseed cake or commercial feed.</div></div>`);
  if(res.dmiD<goals.dmiTarget*0.90)alerts.push(`<div class="alert-item alert-warn"><div class="alert-text"><strong>Low Dry Matter Intake</strong>DMI ${res.dmiD.toFixed(2)}kg below target ${goals.dmiTarget.toFixed(2)}kg.</div></div>`);
  if(!['alert-error','alert-warn'].some(c=>alerts.some(a=>a.includes(c))))alerts.push(`<div class="alert-item alert-ok"><div class="alert-text"><strong>All Nutrient Targets Met</strong>This ration meets ICAR 2013 / NDDB RBP recommendations.</div></div>`);
  return alerts;
}
function renderDietSection(which,res,asmm,goals){
  const rounded={};
  FEEDS.forEach(f=>{
    const wet=res.schedule[f.key]||0;
    if(wet<0.01){rounded[f.key]=0;return;}
    rounded[f.key]=Math.round(wet*10)/10;
  });
  let dmiCheck=FEEDS.reduce((s,f)=>{const w=rounded[f.key]||0;return s+w*(FEED_MATRIX[f.key]?.dm||0.9);},0);
  if(dmiCheck>goals.dmiMax*1.001){
    const toTrim=FEEDS.filter(f=>rounded[f.key]>0&&FEED_MATRIX[f.key]?.cat==='Roughage').sort((a,b)=>(rounded[b.key]||0)-(rounded[a.key]||0));
    for(const f of toTrim){
      while(dmiCheck>goals.dmiMax*1.001&&rounded[f.key]>=0.1){
        rounded[f.key]=Math.round((rounded[f.key]-0.1)*10)/10;
        dmiCheck=FEEDS.reduce((s,ff)=>{const w=rounded[ff.key]||0;return s+w*(FEED_MATRIX[ff.key]?.dm||0.9);},0);
      }
      if(dmiCheck<=goals.dmiMax*1.001)break;
    }
  }
  let dmiD=0,tdnD=0,cpD=0,ndfD=0,caFeedD=0,pFeedD=0;
  FEEDS.forEach(f=>{
    const wet=rounded[f.key]||0;if(!wet)return;
    const fm=FEED_MATRIX[f.key],dm=wet*fm.dm;
    dmiD+=dm;tdnD+=dm*fm.tdn*1000;cpD+=dm*fm.cp*1000;
    ndfD+=dm*fm.ndf;caFeedD+=dm*fm.ca*1000;pFeedD+=dm*fm.p*1000;
  });
  if(tdnD<goals.tdnTargetG*0.97){
    const lockedInDisplay=which==='custom'?Object.fromEntries(Object.entries(customLockMap).filter(([k,v])=>v)):{};
    const topUpCandidates=['commercial_feed','cottonseed_cake','mustard_cake']
      .filter(k=>FEED_MATRIX[k]&&!lockedInDisplay[k]&&(rounded[k]||0)<(FEED_MATRIX[k].maxWetKg||99))
      .sort((a,b)=>FEED_MATRIX[a].cost-FEED_MATRIX[b].cost);
    for(const k of topUpCandidates){
      while(tdnD<goals.tdnTargetG*0.97&&dmiD<goals.dmiMax*0.999){
        const fm=FEED_MATRIX[k],addDm=0.1*fm.dm;
        if(dmiD+addDm>goals.dmiMax)break;
        rounded[k]=(rounded[k]||0)+0.1;
        dmiD+=addDm;tdnD+=addDm*fm.tdn*1000;cpD+=addDm*fm.cp*1000;
        ndfD+=addDm*fm.ndf;caFeedD+=addDm*fm.ca*1000;pFeedD+=addDm*fm.p*1000;
      }
      if(tdnD>=goals.tdnTargetG*0.97)break;
    }
  }
  res={...res,schedule:rounded,dmiD,tdnD,cpD,ndfD,caFeedD,pFeedD};
  asmm=computeAsmm(caFeedD,pFeedD,goals.caTargetG,goals.pTargetG,goals.bw);
  if(which==='custom'&&baselineResult){
    const locked2={};FEEDS.forEach(f=>{if(customLockMap[f.key])locked2[f.key]=customQtyMap[f.key];});
    if((locked2['hmf']||0)>0||(res.schedule['hmf']||0)>0){
      const bRW=FEEDS.filter(f=>f.cat==='Roughage').reduce((s,f)=>s+(baselineResult.schedule[f.key]||0),0);
      const cRW=FEEDS.filter(f=>f.cat==='Roughage').reduce((s,f)=>s+(rounded[f.key]||0),0);
      if(cRW<bRW-0.05){
        const deficit=bRW-cRW;
        const cheapKey=FEEDS.filter(f=>f.cat==='Roughage'&&!locked2[f.key]).sort((a,b)=>a.cost-b.cost)[0]?.key;
        if(cheapKey){
          const roomDm=Math.max(0,goals.dmiMax-dmiD);
          const addWet=Math.min(Math.ceil(deficit*10)/10,Math.floor(roomDm/FEED_MATRIX[cheapKey].dm*10)/10);
          if(addWet>=0.1){
            rounded[cheapKey]=(rounded[cheapKey]||0)+addWet;
            const ad=addWet*FEED_MATRIX[cheapKey].dm;
            dmiD+=ad;tdnD+=ad*FEED_MATRIX[cheapKey].tdn*1000;cpD+=ad*FEED_MATRIX[cheapKey].cp*1000;
            ndfD+=ad*FEED_MATRIX[cheapKey].ndf;caFeedD+=ad*FEED_MATRIX[cheapKey].ca*1000;pFeedD+=ad*FEED_MATRIX[cheapKey].p*1000;
            res={...res,schedule:rounded,dmiD,tdnD,cpD,ndfD,caFeedD,pFeedD};
            asmm=computeAsmm(caFeedD,pFeedD,goals.caTargetG,goals.pTargetG,goals.bw);
          }
        }
      }
    }
  }
  const pfx=which==='baseline'?'baseline':'custom';
  const totalCaG=res.caFeedD+asmm.ca,totalPG=res.pFeedD+asmm.p;
  const ndfPct=res.dmiD>0?(res.ndfD/res.dmiD*100):0;
  const kpis=[
    {label:'DMI',actual:res.dmiD.toFixed(2),target:goals.dmiMax.toFixed(2),unit:'kg',sublabel:`min ${goals.dmiTarget.toFixed(1)}`,pct:res.dmiD/goals.dmiMax},
    {label:'TDN',actual:(res.tdnD/1000).toFixed(1),target:(goals.tdnTargetG/1000).toFixed(1),unit:'kg',pct:res.tdnD/1000/(goals.tdnTargetG/1000)},
    {label:'CP',actual:res.cpD.toFixed(0),target:goals.cpTargetG.toFixed(0),unit:'g',pct:res.cpD/goals.cpTargetG},
    {label:'NDF',actual:ndfPct.toFixed(1)+'%',target:'≥28%',unit:'',pct:ndfPct/28},
    {label:asmm.dose_g>0?`Ca +ASMM ${asmm.dose_g}g`:'Ca (feed only)',actual:totalCaG.toFixed(1),target:goals.caTargetG.toFixed(1),unit:'g',pct:totalCaG/goals.caTargetG},
    {label:asmm.dose_g>0?`P +ASMM ${asmm.dose_g}g`:'P (feed only)',actual:totalPG.toFixed(1),target:goals.pTargetG.toFixed(1),unit:'g',pct:totalPG/goals.pTargetG},
  ];
  document.getElementById(pfx+'Kpis').innerHTML=`<div class="kpi-grid">${kpis.map(k=>{
    const pct=Math.min(k.pct,2),cls=k.pct>=1?'prog-ok':k.pct>=0.9?'prog-warn':'prog-under';
    const tl=k.sublabel?`<span class="kpi-target">cap ${k.target}${k.unit} · ${k.sublabel}${k.unit}</span>`:`<span class="kpi-target">target ${k.target}${k.unit}</span>`;
    return `<div class="kpi-card"><div class="kpi-label">${k.label}</div><div class="kpi-vals"><span class="kpi-actual">${k.actual}${k.unit}</span>${tl}</div><div class="prog-bar-bg"><div class="prog-bar-fill ${cls}" style="width:${Math.min(pct*100,100)}%"></div></div></div>`;
  }).join('')}</div>`;
  const alerts=buildAlerts(res,asmm,goals);
  document.getElementById(pfx+'Alerts').innerHTML=alerts.length?`<div class="alerts-wrap">${alerts.join('')}</div>`:'';
  const activeRows=FEEDS.filter(f=>(res.schedule[f.key]||0)>0.01);
  document.getElementById(pfx+'RationWrap').innerHTML=`<div class="ration-table-wrap"><table class="ration-table">
    <thead><tr><th>Feed</th><th class="num-cell">Wet kg</th><th class="num-cell">DM kg</th><th class="num-cell">TDN g</th><th class="num-cell">CP g</th><th class="num-cell">Ca g</th><th class="num-cell">P g</th><th class="num-cell">Cost &#8377;</th></tr></thead>
    <tbody>
    ${activeRows.map(f=>{const wet=res.schedule[f.key];const dm=wet*(FEED_MATRIX[f.key]?.dm||f.dm);return`<tr><td>${f.name}</td><td class="num-cell">${wet.toFixed(1)}</td><td class="num-cell">${dm.toFixed(3)}</td><td class="num-cell">${(dm*f.tdn*10).toFixed(0)}</td><td class="num-cell">${(dm*f.cp*10).toFixed(0)}</td><td class="num-cell">${(dm*f.ca*10).toFixed(2)}</td><td class="num-cell">${(dm*f.p*10).toFixed(2)}</td><td class="num-cell">${(wet*(customFeedCosts[f.key]||f.cost)).toFixed(1)}</td></tr>`;}).join('')}
    ${asmm.dose_g>0?`<tr class="asmm-row"><td>ASMM (Mineral Mix)</td><td class="num-cell">${(asmm.dose_g/1000).toFixed(3)}</td><td class="num-cell">—</td><td class="num-cell">—</td><td class="num-cell">—</td><td class="num-cell">${asmm.ca.toFixed(2)}</td><td class="num-cell">${asmm.p.toFixed(2)}</td><td class="num-cell">${(asmm.dose_g*(customFeedCosts['asmm']||ASMM.cost_per_g)).toFixed(1)}</td></tr>`:''}
    <tr class="ration-total-row"><td><strong>Total</strong></td><td class="num-cell"><strong>${activeRows.reduce((s,f)=>s+(res.schedule[f.key]||0),0).toFixed(1)}</strong></td><td class="num-cell"><strong>${res.dmiD.toFixed(3)}</strong></td><td class="num-cell"><strong>${res.tdnD.toFixed(0)}</strong></td><td class="num-cell"><strong>${res.cpD.toFixed(0)}</strong></td><td class="num-cell"><strong>${totalCaG.toFixed(2)}</strong></td><td class="num-cell"><strong>${totalPG.toFixed(2)}</strong></td><td class="num-cell"><strong>${calcRationCost(res.schedule,asmm.dose_g).toFixed(1)}</strong></td></tr>
    </tbody></table></div>`;
  document.getElementById(pfx+'AsmmBox').innerHTML=asmm.dose_g>0
    ?`<div class="asmm-box"><strong>Mineral Supplement (ASMM)</strong><br>Feed Ca: <strong>${res.caFeedD.toFixed(1)}g</strong> | Feed P: <strong>${res.pFeedD.toFixed(1)}g</strong> | Targets — Ca: ${goals.caTargetG.toFixed(1)}g, P: ${goals.pTargetG.toFixed(1)}g<br>Recommended ASMM: <strong>${asmm.dose_g}g/day</strong> (driven by ${asmm.caDriver} deficit) → Total Ca: ${totalCaG.toFixed(1)}g, P: ${totalPG.toFixed(2)}g${totalCaG<goals.caTargetG*0.9?' ⚠ Residual Ca gap.':''}${totalPG<goals.pTargetG*0.9?' ⚠ Residual P gap.':''}</div>`
    :`<div class="asmm-box no-asmm"><strong>No Mineral Supplement Needed</strong><br>Feed-sourced Ca: <strong>${res.caFeedD.toFixed(1)}g</strong> (target ${goals.caTargetG.toFixed(1)}g) | P: <strong>${res.pFeedD.toFixed(1)}g</strong> (target ${goals.pTargetG.toFixed(1)}g)<br>Both Ca and P fully met by feed alone — no ASMM required today.</div>`;
  if(which==='baseline')baselineResult={...baselineResult,schedule:rounded,dmiD,tdnD,cpD,ndfD,caFeedD,pFeedD,asmm};
  if(which==='custom')customResult={...customResult,schedule:rounded,dmiD,tdnD,cpD,ndfD,caFeedD,pFeedD,asmm};
}

// ─── CUSTOMISE ───────────────────────────────────────────────────────────────
function openCustomize(){collapseStep('step3Section');renderCustomizeList();openStep('step4Section');}
function renderCustomizeList(){
  const res=baselineResult;
  const bc={'Roughage':'cat-roughage','Green Cereal':'cat-green','Green Legume':'cat-green','Silage':'cat-silage','Hydroponic':'cat-hydro','Concentrate':'cat-conc'};
  let html='';
  CAT_GROUPS.forEach(grp=>{
    const feeds=FEEDS.filter(f=>grp.cats.includes(f.cat)&&baselineChecked[f.key]!==false);if(!feeds.length)return;
    html+=`<div class="feed-section-title">${grp.label}</div><div class="feed-grid">`;
    feeds.forEach(f=>{
      const suggested=res.schedule[f.key]||0;
      const qty=customQtyMap[f.key]!==undefined?customQtyMap[f.key]:suggested;
      const locked=customLockMap[f.key]||false;
      html+=`<div class="feed-customize-row${qty>0?' checked':''}" id="custrow_${f.key}">
        <input type="checkbox" ${qty>0?'checked':''} onchange="toggleCustCheck('${f.key}',this.checked)" id="custchk_${f.key}">
        <div class="feed-name-wrap"><label for="custchk_${f.key}" class="feed-name" title="${f.name}">${f.name}</label><button class="feed-info-btn" onclick="openFeedInfo('${f.key}')">i</button></div>
        <input type="number" class="feed-qty-input${locked?' locked':''}" id="custqty_${f.key}" value="${qty.toFixed(1)}" min="0" step="0.1" onchange="onCustQtyChange('${f.key}')">
        <button class="lock-btn${locked?' active':''}" id="lockbtn_${f.key}" onclick="toggleLock('${f.key}')">${locked?' Locked':'Lock'}</button>
      </div>`;
    });
    html+=`</div>`;
  });
  document.getElementById('customizeFeedList').innerHTML=html;
  const hmfInBaseline=(baselineResult.schedule['hmf']||0)>0.1;
  document.getElementById('hmfPromptWrap').classList[hmfInBaseline?'add':'remove']('hidden');
  if(hmfInBaseline)document.getElementById('hmfCheck').checked=true;
}
function toggleCustCheck(key,val){
  const row=document.getElementById('custrow_'+key);
  if(row){val?row.classList.add('checked'):row.classList.remove('checked');}
  if(!val){customQtyMap[key]=0;document.getElementById('custqty_'+key).value='0.0';}
  else if(!customQtyMap[key]||customQtyMap[key]===0){
    customQtyMap[key]=Math.round((baselineResult.schedule[key]||0.5)*10)/10;
    document.getElementById('custqty_'+key).value=customQtyMap[key].toFixed(1);
  }
}
function onCustQtyChange(key){
  let val=Math.round((parseFloat(document.getElementById('custqty_'+key).value)||0)*10)/10;
  customQtyMap[key]=val;document.getElementById('custqty_'+key).value=val.toFixed(1);
  const row=document.getElementById('custrow_'+key);
  if(row){val>0?row.classList.add('checked'):row.classList.remove('checked');}
}
function toggleLock(key){
  customLockMap[key]=!customLockMap[key];
  const btn=document.getElementById('lockbtn_'+key),inp=document.getElementById('custqty_'+key);
  if(customLockMap[key]){
    btn.classList.add('active');btn.textContent=' Locked';inp.classList.add('locked');
    const snapped=Math.round((parseFloat(inp.value)||0)*10)/10;
    customQtyMap[key]=snapped;inp.value=snapped.toFixed(1);
  }else{btn.classList.remove('active');btn.textContent='Lock';inp.classList.remove('locked');}
}
function enforceRoughageFloor(cR,baseRes,lockedFeeds,dmiMaxG){
  if(!baseRes||(lockedFeeds['hmf']||0)<=0)return;
  const baseRoughWet=FEEDS.filter(f=>f.cat==='Roughage').reduce((s,f)=>s+(baseRes.schedule[f.key]||0),0);
  const custRoughWet=FEEDS.filter(f=>f.cat==='Roughage').reduce((s,f)=>s+(cR.schedule[f.key]||0),0);
  if(custRoughWet<baseRoughWet-0.05){
    const deficit=baseRoughWet-custRoughWet;
    const cheapKey=FEEDS.filter(f=>f.cat==='Roughage'&&!lockedFeeds[f.key]).sort((a,b)=>a.cost-b.cost)[0]?.key;
    if(cheapKey){
      const roomDm=dmiMaxG?Math.max(0,dmiMaxG-cR.dmiD):999;
      const addWet=Math.min(deficit,roomDm/FEED_MATRIX[cheapKey].dm);
      if(addWet>0.01){
        cR.schedule[cheapKey]=(cR.schedule[cheapKey]||0)+addWet;
        const addDm=addWet*FEED_MATRIX[cheapKey].dm;
        cR.dmiD+=addDm;cR.tdnD+=addDm*FEED_MATRIX[cheapKey].tdn*1000;
        cR.cpD+=addDm*FEED_MATRIX[cheapKey].cp*1000;cR.ndfD+=addDm*FEED_MATRIX[cheapKey].ndf;
        cR.caFeedD+=addDm*FEED_MATRIX[cheapKey].ca*1000;cR.pFeedD+=addDm*FEED_MATRIX[cheapKey].p*1000;
      }
    }
  }
}
function recalculateCustom(){
  const locked={};
  FEEDS.forEach(f=>{
    const raw=parseFloat(document.getElementById('custqty_'+f.key)?.value)||0;
    const val=Math.round(raw*10)/10;
    customQtyMap[f.key]=val;
    if(customLockMap[f.key])locked[f.key]=val;
  });
  const hmfBox=document.getElementById('hmfCheck');
  if(hmfBox&&hmfBox.checked&&locked['hmf']===undefined){
    const hq=Math.round((parseFloat(document.getElementById('hmfQtyInput')?.value)||5)*10)/10;
    locked['hmf']=hq;customQtyMap['hmf']=hq;
  }
  const checkedSet=new Set(FEEDS.filter(f=>baselineChecked[f.key]!==false).map(f=>f.key));
  Object.keys(locked).forEach(k=>checkedSet.add(k));
  const res=runSolverCore({...goalsState,_costMinimise:true,_baselineCaps:baselineResult?baselineResult.schedule:null},locked,Array.from(checkedSet));
  enforceRoughageFloor(res,baselineResult,locked,goalsState.dmiMax);
  const asmm=computeAsmm(res.caFeedD,res.pFeedD,goalsState.caTargetG,goalsState.pTargetG,goalsState.bw);
  customResult={...res,asmm,goals:goalsState};
  document.getElementById('step4Num').classList.add('done');
  collapseStep('step4Section');renderDietSection('custom',res,asmm,goalsState);openStep('step5Section');
  document.getElementById('exportSection').classList.remove('hidden');
}

function getMilkPrice(){
  if(milkPricePerLitre)return milkPricePerLitre;
  const fat=goalsState.fat||4.0;
  if(goalsState.animalType==='buffalo')return(fat/100)*875*1.03;
  const snf=8.5,eqFat=fat+(snf*(2/3));
  return(eqFat/100)*388.65*1.03;
}
function openEconomics(which){
  if(which==='baseline'){document.getElementById('econBaselineContent').innerHTML=renderEconContent('baseline',null);openStep('econBaselineSection');}
  else{document.getElementById('econCustomContent').innerHTML=renderEconContent('custom','baseline');openStep('econCustomSection');}
  document.getElementById('exportSection').classList.remove('hidden');
}
function renderEconContent(which,compareWith){
  const r=which==='baseline'?baselineResult:customResult;if(!r)return '<p>No data yet.</p>';
  const ls=goalsState.lifeStage,isLac=ls==='lactating',milk=goalsState.milk||0,bw=goalsState.bw||450;
  const mp=getMilkPrice(),dailyInc=milk*mp;
  const cost=calcRationCost(r.schedule,r.asmm.dose_g);
  const cpl=milk>0?cost/milk:0,costPct=dailyInc>0?cost/dailyInc*100:0;
  let breakdown='';
  FEEDS.forEach(f=>{const wet=r.schedule[f.key]||0;if(wet<0.01)return;breakdown+=`<div class="econ-line"><span>${f.name} (${wet.toFixed(1)} kg)</span><span class="econ-val">&#8377;${(wet*(customFeedCosts[f.key]||f.cost)).toFixed(1)}</span></div>`;});
  if(r.asmm.dose_g>0)breakdown+=`<div class="econ-line"><span>ASMM (${r.asmm.dose_g}g)</span><span class="econ-val">&#8377;${(r.asmm.dose_g*ASMM.cost_per_g).toFixed(1)}</span></div>`;
  let costInputs=`<div style="font-size:12px;font-weight:700;text-transform:uppercase;color:var(--gray-400);margin-bottom:8px;">Edit Feed Costs (&#8377;/kg)</div><div class="econ-input-row">`;
  FEEDS.forEach(f=>{const wet=r.schedule[f.key]||0;if(wet<0.01)return;costInputs+=`<div class="field"><label>${f.name}</label><input type="number" value="${customFeedCosts[f.key]||f.cost}" min="1" step="0.5" onchange="customFeedCosts['${f.key}']=parseFloat(this.value)||${f.cost};FEED_MATRIX['${f.key}'].cost=customFeedCosts['${f.key}'];markCostsDirty('${which}');updateEcon();"></div>`;});
  if(isLac)costInputs+=`<div class="field"><label>Milk Price (&#8377;/litre)</label><input type="number" value="${mp.toFixed(2)}" min="10" step="1" onchange="milkPricePerLitre=parseFloat(this.value);updateEcon();"></div>`;
  costInputs+=`</div>`;
  const dirty=window['costsDirty_'+which]||false;
  const reoptBtn=dirty?`<div style="margin-top:14px;background:#fff3cd;border:1.5px solid #e8a020;border-radius:8px;padding:12px 16px;display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:10px;"><div><div style="font-size:13px;font-weight:700;color:#92400e;">Costs changed — diet not yet re-optimised</div><div style="font-size:12px;color:#78350f;margin-top:2px;">Re-run to get cheapest balanced diet at new costs.</div></div><button onclick="reoptimiseDiet('${which}')" style="background:#1a3a2a;color:white;border:none;padding:10px 18px;border-radius:8px;font-family:Sora,sans-serif;font-size:13px;font-weight:600;cursor:pointer;white-space:nowrap;">Re-optimise Diet</button></div>`:'';
  let summaryMetrics='';
  if(isLac){
    const bCls=costPct<80?'econ-banner good':'econ-banner warn';
    const bMsg=costPct<80?` Feed cost is ${costPct.toFixed(1)}% of daily milk income — within healthy range.`:` Feed cost is ${costPct.toFixed(1)}% of daily milk income — above 80% threshold.`;
    summaryMetrics=`<div class="econ-comparison"><div style="padding:12px;background:var(--gray-100);border-radius:var(--radius-sm);">
      <div class="econ-line"><span>Total feed cost/day</span><span class="econ-val">&#8377;${cost.toFixed(1)}</span></div>
      <div class="econ-line"><span>Milk income/day</span><span class="econ-val">&#8377;${dailyInc.toFixed(1)}</span></div>
      <div class="econ-line"><span>Cost per litre milk</span><span class="econ-val">&#8377;${cpl.toFixed(2)}</span></div>
      <div class="econ-line"><span>Cost as % of income</span><span class="econ-val">${costPct.toFixed(1)}%</span></div>
    </div></div><div class="${bCls} mt14">${bMsg}</div>`;
  }else{
    const stageLabel=ls==='calf'?'Heifer / Calf':ls==='dry'?'Dry Cow':ls==='pregnant_t1'?'Pregnant T1':ls==='pregnant_t2'?'Pregnant T2':'Pregnant T3';
    summaryMetrics=`<div class="econ-comparison"><div style="padding:12px;background:var(--gray-100);border-radius:var(--radius-sm);">
      <div class="econ-line"><span>Total feed cost/day</span><span class="econ-val">&#8377;${cost.toFixed(1)}</span></div>
      <div class="econ-line"><span>Cost per kg body weight</span><span class="econ-val">&#8377;${(cost/bw).toFixed(2)}</span></div>
      <div class="econ-line"><span>Monthly feed cost (est.)</span><span class="econ-val">&#8377;${(cost*30).toFixed(0)}</span></div>
    </div></div><div class="econ-banner good mt14">Daily maintenance cost for ${stageLabel}: &#8377;${cost.toFixed(1)}/day</div>`;
  }
  let compareHtml='';
  if(compareWith==='baseline'&&baselineResult){
    const costB=calcRationCost(baselineResult.schedule,baselineResult.asmm.dose_g);
    const savDay=costB-cost,savMo=savDay*30;
    const savCol=savMo>=0?'var(--green-dark)':'var(--red)';
    const savSign=savMo>=0?'+':'-';
    let cardRows='';
    if(isLac){
      const cplB=milk>0?costB/milk:0,pctB=dailyInc>0?costB/dailyInc*100:0;
      cardRows=`<div class="econ-comparison">
        <div class="econ-card baseline"><div class="econ-card-title">Baseline Diet</div>
          <div class="econ-line"><span>Daily feed cost</span><span class="econ-val">&#8377;${costB.toFixed(1)}</span></div>
          <div class="econ-line"><span>Cost per litre</span><span class="econ-val">&#8377;${cplB.toFixed(2)}</span></div>
          <div class="econ-line"><span>% of milk income</span><span class="econ-val">${pctB.toFixed(1)}%</span></div></div>
        <div class="econ-card custom"><div class="econ-card-title">Customised Diet</div>
          <div class="econ-line"><span>Daily feed cost</span><span class="econ-val">&#8377;${cost.toFixed(1)}</span></div>
          <div class="econ-line"><span>Cost per litre</span><span class="econ-val">&#8377;${cpl.toFixed(2)}</span></div>
          <div class="econ-line"><span>% of milk income</span><span class="econ-val">${costPct.toFixed(1)}%</span></div></div>
      </div>`;
    }else{
      cardRows=`<div class="econ-comparison">
        <div class="econ-card baseline"><div class="econ-card-title">Baseline Diet</div>
          <div class="econ-line"><span>Daily feed cost</span><span class="econ-val">&#8377;${costB.toFixed(1)}</span></div>
          <div class="econ-line"><span>Monthly cost</span><span class="econ-val">&#8377;${(costB*30).toFixed(0)}</span></div></div>
        <div class="econ-card custom"><div class="econ-card-title">Customised Diet</div>
          <div class="econ-line"><span>Daily feed cost</span><span class="econ-val">&#8377;${cost.toFixed(1)}</span></div>
          <div class="econ-line"><span>Monthly cost</span><span class="econ-val">&#8377;${(cost*30).toFixed(0)}</span></div></div>
      </div>`;
    }
    if(isLac&&savDay<0){
      compareHtml=`<div class="divider"></div>
        <div style="background:#f0f7f4;border:1px solid #b6d9c8;border-radius:8px;padding:16px 18px;margin-top:14px;font-size:13px;color:#1a3a2a;line-height:1.6">
          <strong>Note on customised diet cost</strong><br>
          There is some additional monthly cost with customised diet having HMF. The slightly extra amount provides year-round fodder availability, better digestibility and improved Ca:P balance.
        </div>`;
    }else{
      compareHtml=`<div class="divider"></div><div class="section-label">Comparison: Baseline vs Customised</div>${cardRows}
        <div class="econ-savings mt14">
          <div class="econ-savings-label">${savMo>=0?'Monthly savings with customised diet':'Additional monthly cost with customised diet'}</div>
          <div class="econ-savings-val" style="color:${savCol}">${savSign}&#8377;${Math.abs(savMo).toFixed(0)}/month</div>
        </div>`;
    }
  }
  return `<div class="econ-section">${reoptBtn}<div class="section-label">Daily Feed Breakdown</div>${breakdown}<div class="divider"></div>${summaryMetrics}${compareHtml}<div class="divider"></div>${costInputs}</div>`;
}
function markCostsDirty(which){window['costsDirty_'+which]=true;updateEcon();}
function updateEcon(){
  if(!document.getElementById('econBaselineSection').classList.contains('hidden'))document.getElementById('econBaselineContent').innerHTML=renderEconContent('baseline',null);
  if(!document.getElementById('econCustomSection').classList.contains('hidden'))document.getElementById('econCustomContent').innerHTML=renderEconContent('custom','baseline');
}
function reoptimiseDiet(which){
  if(which==='baseline'&&goalsState&&baselineResult){
    const checked=baselineResult.checked||FEEDS.filter(f=>baselineChecked[f.key]!==false).map(f=>f.key);
    const res=runSolverCore({...goalsState,_costMinimise:true},{},checked);
    const asmm=computeAsmm(res.caFeedD,res.pFeedD,goalsState.caTargetG,goalsState.pTargetG,goalsState.bw);
    baselineResult={...res,asmm,goals:goalsState,checked};
    renderDietSection('baseline',res,asmm,goalsState);
    if(customResult){
      const cL={};Object.entries(customQtyMap).forEach(([k,v])=>{if(customLockMap[k])cL[k]=v;});
      const custFeeds=[...new Set([...checked,...Object.keys(cL)])];
      const cR=runSolverCore({...goalsState,_costMinimise:true,_baselineCaps:res.schedule},cL,custFeeds);
      enforceRoughageFloor(cR,{...res},cL,goalsState.dmiMax);
      const cA=computeAsmm(cR.caFeedD,cR.pFeedD,goalsState.caTargetG,goalsState.pTargetG,goalsState.bw);
      customResult={...cR,asmm:cA,goals:goalsState};renderDietSection('custom',cR,cA,goalsState);
    }
    window['costsDirty_baseline']=false;window['costsDirty_custom']=false;updateEcon();
    setTimeout(()=>{try{document.getElementById('step3Section').scrollIntoView({behavior:'smooth',block:'start'});}catch(e){}},150);
  }else if(which==='custom'&&goalsState&&customResult){
    const cL={};Object.entries(customQtyMap).forEach(([k,v])=>{if(customLockMap[k])cL[k]=v;});
    const chk=FEEDS.filter(f=>baselineChecked[f.key]!==false).map(f=>f.key);
    const bR=runSolverCore({...goalsState,_costMinimise:true},{},chk);
    const bA=computeAsmm(bR.caFeedD,bR.pFeedD,goalsState.caTargetG,goalsState.pTargetG,goalsState.bw);
    baselineResult={...bR,asmm:bA,goals:goalsState,checked:chk};
    const custFeeds2=[...new Set([...chk,...Object.keys(cL)])];
    const cR=runSolverCore({...goalsState,_costMinimise:true,_baselineCaps:bR.schedule},cL,custFeeds2);
    enforceRoughageFloor(cR,bR,cL,goalsState.dmiMax);
    const cA=computeAsmm(cR.caFeedD,cR.pFeedD,goalsState.caTargetG,goalsState.pTargetG,goalsState.bw);
    customResult={...cR,asmm:cA,goals:goalsState};renderDietSection('custom',cR,cA,goalsState);
    renderDietSection('baseline',bR,bA,goalsState);
    window['costsDirty_baseline']=false;window['costsDirty_custom']=false;updateEcon();
    setTimeout(()=>{try{document.getElementById('step5Section').scrollIntoView({behavior:'smooth',block:'start'});}catch(e){}},150);
  }
}

function exportPDF(){
  if(!goalsState){showToast('Please calculate a diet first.');return;}

  const g=goalsState, milk=g.milk||0, bw=g.bw||450, isLac=g.lifeStage==='lactating';
  const mp=getMilkPrice();
  const aLabel=g.animalType==='cow_crossbred'?'Crossbred Cow':g.animalType==='cow_indigenous'?'Indigenous Cow':'Buffalo';
  const date=new Date().toLocaleDateString('en-IN',{day:'2-digit',month:'long',year:'numeric'});
  const logo='https://www.shunya.live/wp-content/uploads/2026/02/Sunya_Logo_highres-1-scaled.png';

  function esc(s){return String(s).replace(/&/g,'&amp;').replace(/</g,'&lt;').replace(/>/g,'&gt;');}

  function rationRows(res){
    if(!res)return '';
    const ar=FEEDS.filter(function(f){return(res.schedule[f.key]||0)>0.01;});
    let rows=ar.map(function(f){
      const wet=res.schedule[f.key];
      const dm=wet*(FEED_MATRIX[f.key]?FEED_MATRIX[f.key].dm:f.dm);
      return '<tr><td>'+esc(f.name)+'</td><td>'+wet.toFixed(1)+'</td><td>'+dm.toFixed(3)+'</td><td>'+(dm*f.tdn*10).toFixed(0)+'</td><td>'+(dm*f.cp*10).toFixed(0)+'</td><td>&#8377;'+(wet*(customFeedCosts[f.key]||f.cost)).toFixed(1)+'</td></tr>';
    }).join('');
    if(res.asmm&&res.asmm.dose_g>0){
      rows+='<tr style="background:#fff7e6"><td>ASMM '+res.asmm.dose_g+'g/day</td><td>'+(res.asmm.dose_g/1000).toFixed(3)+'</td><td>&#8212;</td><td>&#8212;</td><td>&#8212;</td><td>&#8377;'+(res.asmm.dose_g*ASMM.cost_per_g).toFixed(1)+'</td></tr>';
    }
    const tc=calcRationCost(res.schedule,res.asmm?res.asmm.dose_g:0);
    const totalWet=ar.reduce(function(s,f){return s+(res.schedule[f.key]||0);},0);
    rows+='<tr class="total-row"><td><b>TOTAL</b></td><td><b>'+totalWet.toFixed(1)+'</b></td><td><b>'+res.dmiD.toFixed(3)+'</b></td><td><b>'+res.tdnD.toFixed(0)+'</b></td><td><b>'+res.cpD.toFixed(0)+'</b></td><td><b>&#8377;'+tc.toFixed(1)+(isLac&&milk>0?' (&#8377;'+(tc/milk).toFixed(2)+'/L)':'')+'</b></td></tr>';
    return rows;
  }

  let savingsHtml='';
  if(baselineResult&&customResult){
    const cB=calcRationCost(baselineResult.schedule,baselineResult.asmm.dose_g);
    const cC=calcRationCost(customResult.schedule,customResult.asmm.dose_g);
    const sD=cB-cC, sM=sD*30, sY=sD*365, sg=sD>=0?'+':'-';
    const col=sD>=0?'#166534':'#991b1b';
    savingsHtml='<div class="savings-box">'
      +'<div class="section-title">Savings Summary</div>'
      +'<table><thead><tr><th>Metric</th><th>Baseline</th><th>Customised</th><th>Change</th></tr></thead><tbody>'
      +'<tr><td>Daily Feed Cost</td><td>&#8377;'+cB.toFixed(1)+'</td><td>&#8377;'+cC.toFixed(1)+'</td><td style="color:'+col+';font-weight:700">'+sg+'&#8377;'+Math.abs(sD).toFixed(1)+'/day</td></tr>'
      +(isLac&&milk>0?'<tr><td>Cost per Litre</td><td>&#8377;'+(cB/milk).toFixed(2)+'</td><td>&#8377;'+(cC/milk).toFixed(2)+'</td><td style="color:'+col+';font-weight:700">'+sg+'&#8377;'+Math.abs(cB/milk-cC/milk).toFixed(2)+'/L</td></tr>':'')
      +'<tr><td><b>Monthly Saving</b></td><td colspan="2" style="text-align:center">30 days</td><td style="color:'+col+';font-weight:800;font-size:15px">'+sg+'&#8377;'+Math.abs(sM).toFixed(0)+'</td></tr>'
      +'<tr><td><b>Annual Saving</b></td><td colspan="2" style="text-align:center">365 days</td><td style="color:'+col+';font-weight:800;font-size:15px">'+sg+'&#8377;'+Math.abs(sY).toFixed(0)+'</td></tr>'
      +'</tbody></table></div>';
  }

  let milkEconHtml='';
  if(isLac&&milk>0&&baselineResult){
    const cB=calcRationCost(baselineResult.schedule,baselineResult.asmm.dose_g);
    const dailyInc=milk*mp, pctB=dailyInc>0?cB/dailyInc*100:0;
    const col=pctB<80?'#166534':'#c0392b';
    milkEconHtml='<div class="econ-box">'
      +'<div class="section-title">Milk Economics</div>'
      +'<table><tbody>'
      +'<tr><td>Milk income/day</td><td><b>&#8377;'+dailyInc.toFixed(1)+'</b> (@&#8377;'+mp.toFixed(2)+'/L &times; '+milk+'L)</td></tr>'
      +'<tr><td>Feed cost per litre</td><td><b>&#8377;'+(cB/milk).toFixed(2)+'</b></td></tr>'
      +'<tr><td>Feed cost % of income</td><td style="font-weight:700;color:'+col+'">'+pctB.toFixed(1)+'% '+(pctB<80?'&#10003; Healthy':'&#9888; Above 80%')+'</td></tr>'
      +'</tbody></table></div>';
  }

  const html='<!DOCTYPE html><html><head><meta charset="UTF-8">'
    +'<title>Shunya FeedRight Diet Report</title>'
    +'<style>'
    +'*{box-sizing:border-box;margin:0;padding:0}'
    +'body{font-family:Arial,Helvetica,sans-serif;font-size:13px;color:#111;padding:24px;max-width:800px;margin:0 auto}'
    +'h2{font-size:18px;color:#1a3a2a;margin-bottom:4px}'
    +'.subtitle{font-size:12px;color:#6b7280;margin-bottom:16px}'
    +'.hdr{display:flex;justify-content:space-between;align-items:center;border-bottom:3px solid #1a3a2a;padding-bottom:12px;margin-bottom:18px}'
    +'.hdr-title{font-size:19px;font-weight:800;color:#1a3a2a}'
    +'.hdr-date{font-size:11px;color:#9ca3af;margin-top:3px}'
    +'.animal-grid{display:flex;gap:24px;flex-wrap:wrap;margin-bottom:16px;font-size:13px}'
    +'.animal-grid span{font-weight:700;margin-right:4px}'
    +'.kpi-row{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:20px}'
    +'.kpi{border:1px solid #d1d5db;border-radius:6px;padding:8px 12px;background:#f9fafb;min-width:80px}'
    +'.kpi-label{font-size:9px;color:#6b7280;font-weight:700;text-transform:uppercase;letter-spacing:.05em}'
    +'.kpi-val{font-size:15px;font-weight:800;color:#1a3a2a;margin-top:2px}'
    +'.section-title{font-size:14px;font-weight:800;color:#1a3a2a;margin:20px 0 8px}'
    +'table{width:100%;border-collapse:collapse;font-size:12px;margin-bottom:4px}'
    +'th{background:#1a3a2a;color:#fff;padding:7px 8px;text-align:left;font-size:11px}'
    +'td{padding:6px 8px;border-bottom:1px solid #e5e7eb}'
    +'.total-row td{background:#e8f5ec;font-weight:700}'
    +'.savings-box{margin-top:18px;padding:14px 16px;border:2px solid #2d5a3d;border-radius:8px;background:#f0faf3}'
    +'.econ-box{margin-top:14px;padding:12px 14px;border:1.5px solid #2d5a3d;border-radius:8px;background:#f0faf3}'
    +'.econ-box td{border-bottom:1px solid #c6e6d0}'
    +'.disclaimer{margin-top:24px;padding-top:12px;border-top:1px solid #e5e7eb;font-size:10px;color:#9ca3af}'
    +'@media print{body{padding:0}}'
    +'</style></head><body>'
    +'<div class="hdr">'
    +'<img src="'+logo+'" style="height:50px;object-fit:contain" crossorigin="anonymous">'
    +'<div style="text-align:right"><div class="hdr-title">Shunya Feed Right</div><div class="hdr-date">'+esc(date)+'</div></div>'
    +'</div>'
    +'<h2>Diet Advisory Report</h2>'
    +'<div class="subtitle">ICAR 2013 &middot; NDDB RBP Method</div>'
    +'<div class="animal-grid">'
    +'<div><span>Animal:</span>'+esc(aLabel)+'</div>'
    +'<div><span>Stage:</span>'+esc(g.lifeStage)+'</div>'
    +'<div><span>Weight:</span>'+bw+' kg</div>'
    +(isLac?'<div><span>Milk:</span>'+milk+' L/day @ '+g.fat+'% fat</div>':'')
    +'</div>'
    +'<div class="kpi-row">'
    +[{l:'DMI',v:g.dmiTarget.toFixed(2)+' kg'},{l:'TDN',v:(g.tdnTargetG/1000).toFixed(2)+' kg'},{l:'CP',v:g.cpTargetG.toFixed(0)+' g'},{l:'Ca',v:g.caTargetG.toFixed(1)+' g'},{l:'P',v:g.pTargetG.toFixed(1)+' g'}]
      .map(function(k){return'<div class="kpi"><div class="kpi-label">'+k.l+'</div><div class="kpi-val">'+k.v+'</div></div>';}).join('')
    +'</div>'
    +(baselineResult?'<div class="section-title">Baseline Recommended Diet</div><table><thead><tr><th>Feed</th><th>Wet kg</th><th>DM kg</th><th>TDN g</th><th>CP g</th><th>Cost</th></tr></thead><tbody>'+rationRows(baselineResult)+'</tbody></table>':'')
    +milkEconHtml
    +(customResult?'<div class="section-title">Customised Diet</div><table><thead><tr><th>Feed</th><th>Wet kg</th><th>DM kg</th><th>TDN g</th><th>CP g</th><th>Cost</th></tr></thead><tbody>'+rationRows(customResult)+'</tbody></table>':'')
    +savingsHtml
    +'<div class="disclaimer">Generated by Shunya Feed Right BETA &middot; ICAR 2013 / NDDB RBP &middot; Advisory use only. Consult a veterinarian before changing your animal\'s diet.</div>'
    +'</body></html>';

  // Open in new tab — user prints to PDF / shares from there
  const win=window.open('','_blank');
  if(!win){showToast('Please allow popups for this site, then try again.');return;}
  win.document.write(html);
  win.document.close();
  // On mobile, trigger print immediately so the share/save dialog appears
  win.onload=function(){
    setTimeout(function(){win.print();},300);
  };
  // If onload already fired (cached)
  if(win.document.readyState==='complete'){
    setTimeout(function(){win.print();},400);
  }
}

function showToast(msg){
  let t=document.getElementById('sfrToast');
  if(!t){t=document.createElement('div');t.id='sfrToast';t.style.cssText='position:fixed;bottom:24px;left:50%;transform:translateX(-50%);background:#1a3a2a;color:#fff;padding:12px 20px;border-radius:8px;font-size:13px;z-index:99999;max-width:90vw;text-align:center;box-shadow:0 4px 16px rgba(0,0,0,0.25);transition:opacity 0.3s';document.body.appendChild(t);}
  t.textContent=msg;t.style.opacity='1';clearTimeout(t._t);t._t=setTimeout(()=>{t.style.opacity='0';},4000);
}

// Init
onLifeStageChange();
FEEDS.forEach(f=>{baselineChecked[f.key]=true;});
buildSources();

// ── Static element event bindings (replaces all removed inline handlers) ──

// Header: Sources button
document.getElementById('sourcesModal') && void 0; // modal already exists
document.querySelector('.sources-btn') && document.querySelector('.sources-btn').addEventListener('click', function(){ openModal('sourcesModal'); });

// Modal close buttons
document.querySelector('#sourcesModal .modal-close') && document.querySelector('#sourcesModal .modal-close').addEventListener('click', function(){ closeModal('sourcesModal'); });
document.querySelector('#infoModal .modal-close') && document.querySelector('#infoModal .modal-close').addEventListener('click', function(){ closeModal('infoModal'); });

// Feed info image expand
var infoImgPh = document.getElementById('infoImgPlaceholder');
if(infoImgPh) infoImgPh.addEventListener('click', function(){ expandFeedImage(this); });

// About accordion toggle
(function(){
  var aboutBtns = document.querySelectorAll('.container > div:first-child button');
  aboutBtns.forEach(function(btn){
    btn.addEventListener('click', function(){
      var panel = this.nextElementSibling;
      panel.style.display = panel.style.display === 'none' ? 'block' : 'none';
      var chev = this.querySelector('.chev');
      if(chev) chev.textContent = chev.textContent === '▾' ? '▸' : '▾';
    });
  });
})();

// Step section header toggles
['step1Section','step2Section','step22Section','step3Section','step4Section','step5Section','econBaselineSection','econCustomSection'].forEach(function(id){
  var section = document.getElementById(id);
  if(!section) return;
  var header = section.querySelector('.step-header');
  if(header) header.addEventListener('click', function(){ toggleStep(id); });
});

// Animal type change
var animalTypeEl = document.getElementById('animalType');
if(animalTypeEl) animalTypeEl.addEventListener('change', function(){
  var fi = document.getElementById('fatPct'); if(!fi) return;
  if(this.value==='cow_indigenous') fi.value=4.5;
  else if(this.value==='cow_crossbred') fi.value=3.5;
  updateBreedNote();
});

// Life stage change
var lifeStageEl = document.getElementById('lifeStage');
if(lifeStageEl) lifeStageEl.addEventListener('change', onLifeStageChange);

// Step 1: Confirm Animal Details
var confirmBtn = document.querySelector('#step1Section .btn-primary');
if(confirmBtn) confirmBtn.addEventListener('click', confirmAnimalDetails);

// Step 2: Confirm Targets -> Select Feeds
var step2Btn = document.querySelector('#step2Section .btn-primary');
if(step2Btn) step2Btn.addEventListener('click', openStep22);

// Step 2.1: Calculate Baseline
var baselineBtn = document.querySelector('#step22Section .btn-primary');
if(baselineBtn) baselineBtn.addEventListener('click', calculateBaseline);

// Step 3: Customise + Check Economics (baseline)
var customiseBtn = document.querySelector('#step3Section .btn-secondary');
if(customiseBtn) customiseBtn.addEventListener('click', openCustomize);
var econBaseBtn = document.querySelector('#step3Section .btn-outline-gray');
if(econBaseBtn) econBaseBtn.addEventListener('click', function(){ openEconomics('baseline'); });

// Step 4: Redesign Diet
var redesignBtn = document.querySelector('#step4Section .btn-purple');
if(redesignBtn) redesignBtn.addEventListener('click', recalculateCustom);

// Step 5: Check Economics (custom)
var econCustomBtn = document.querySelector('#step5Section .btn-purple');
if(econCustomBtn) econCustomBtn.addEventListener('click', function(){ openEconomics('custom'); });

// Export
var exportBtnEl = document.getElementById('exportBtn');
if(exportBtnEl) exportBtnEl.addEventListener('click', exportPDF);

// Modal overlay click-to-close
document.querySelectorAll('.modal-overlay').forEach(function(el){
  el.addEventListener('click', function(e){ if(e.target===this) closeModal(this.id); });
});