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= (sel, ctx=document) => Array.from(ctx.querySelectorAll(sel)); const fmtUSD = new Intl.NumberFormat('en-US', {style:'currency', currency:'USD', maximumFractionDigits:2}); const fmtPct = (v)=> (isFinite(v) ? (v*100).toFixed(2)+'%' : '0.00%'); // Data: 2024 brackets (rates and thresholds) from Nebraska 2024 Tax Calculation Schedule // Note: Values below reflect commonly published 2024 thresholds/rates. // Always verify against the official schedule linked in the Data Source section. const BRACKETS_2024 = { single: [ { upTo: 3370, rate: 0.0246, lower: 0 }, { upTo: 20590, rate: 0.0351, lower: 3370 }, { upTo: 33180, rate: 0.0501, lower: 20590 }, { upTo: Infinity, rate: 0.0664, lower: 33180 } ], mfj: [ { upTo: 6730, rate: 0.0246, lower: 0 }, { upTo: 41190, rate: 0.0351, lower: 6730 }, { upTo: 66380, rate: 0.0501, lower: 41190 }, { upTo: Infinity, rate: 0.0664, lower: 66380 } ], // For 2024, many references align HOH thresholds closely with Single. Verify against the schedule for filing. hoh: [ { upTo: 3370, rate: 0.0246, lower: 0 }, { upTo: 20590, rate: 0.0351, lower: 3370 }, { upTo: 33180, rate: 0.0501, lower: 20590 }, { upTo: Infinity, rate: 0.0664, lower: 33180 } ] }; // Standard deduction (federal) 2024 for estimator convenience const STD_DED_2024 = { single: 14600, mfj: 29200, hoh: 21900 }; // Elements const taxYear = $('#taxYear'); const modeTaxable = $('#mode-taxable'); const modeGross = $('#mode-gross'); const taxableGroup = $('#taxable-group'); const grossPanel = $('#gross-panel'); const taxableIncome = $('#taxableIncome'); const grossIncome = $('#grossIncome'); const preTax = $('#preTax'); const itemizedWrap = $('#itemizedWrap'); const itemizedDeduction = $('#itemizedDeduction'); const stdDeductionWrap = $('#stdDeductionWrap'); const standardDeduction = $('#standardDeduction'); const credits = $('#credits'); const calcBtn = $('#calcBtn'); const resetBtn = $('#resetBtn'); const rTaxable = $('#rTaxable'); const rTax = $('#rTax'); const rMarginal = $('#rMarginal'); const rEffective = $('#rEffective'); const rAfterTax = $('#rAfterTax'); const afterTaxRow = $('#afterTaxRow'); // Filing status const getStatus = () => { const sel =

('input[name="deductionMode"]').find(r => r.checked); return sel ? sel.value : 'standard'; }; // Tooltips toggle function setupTooltip(containerId, btnSelector='button'){ const tip = $('#'+containerId); const wrap = tip?.parentElement; const btn = wrap?.querySelector(btnSelector); if(!tip || !btn || !wrap) return; const toggle = ()=>{ const expanded = wrap.getAttribute('aria-expanded') === 'true'; wrap.setAttribute('aria-expanded', String(!expanded)); btn.setAttribute('aria-expanded', String(!expanded)); }; btn.addEventListener('click', toggle); btn.addEventListener('keydown', (e)=>{ if(e.key === ' ' || e.key === 'Enter'){ e.preventDefault(); toggle(); } }); } setupTooltip('taxableHelp'); setupTooltip('preTaxHelp'); setupTooltip('creditsHelp'); // Validation helpers function setError(input, msg, errId){ if(!input) return; input.setAttribute('aria-invalid', 'true'); const err = $('#'+errId); if(err){ err.textContent = msg || ''; } } function clearError(input, errId){ if(!input) return; input.setAttribute('aria-invalid', 'false'); const err = $('#'+errId); if(err){ err.textContent = ''; } } // Attach on-blur validation function validateNumber(input, errId, opts = {required:false, min:0}){ const v = input.value.trim(); if(opts.required && v === ''){ setError(input, 'Please enter a value.', errId); return false; } if(v !== ''){ const num = Number(v); if(!isFinite(num)){ setError(input, 'Please enter a valid number.', errId); return false; } if(typeof opts.min === 'number' && num < opts.min){ setError(input, `Value must be ≥ ${opts.min}.`, errId); return false; } } clearError(input, errId); return true; } taxableIncome.addEventListener('blur', ()=> validateNumber(taxableIncome, 'taxableErr', {required: modeTaxable.checked, min:0})); grossIncome.addEventListener('blur', ()=> validateNumber(grossIncome, 'grossErr', {required: modeGross.checked, min:0})); preTax.addEventListener('blur', ()=> validateNumber(preTax, 'preTaxErr', {required:false, min:0})); itemizedDeduction.addEventListener('blur', ()=> validateNumber(itemizedDeduction, 'itemizedErr', {required: getDeductionMode()==='itemized' && modeGross.checked, min:0})); credits.addEventListener('blur', ()=> validateNumber(credits, 'creditsErr', {required:false, min:0})); // Mode switching function syncMode(){ const usingGross = modeGross.checked; if(usingGross){ grossPanel.hidden = false; taxableGroup.hidden = true; // Set required flags programmatically for SR/validation taxableIncome.removeAttribute('aria-required'); grossIncome.setAttribute('aria-required', 'true'); // Deduction UI swap const dm = getDeductionMode(); if(dm === 'standard'){ itemizedWrap.hidden = true; stdDeductionWrap.hidden = false; }else{ itemizedWrap.hidden = false; stdDeductionWrap.hidden = true; } }else{ grossPanel.hidden = true; taxableGroup.hidden = false; taxableIncome.setAttribute('aria-required', 'true'); grossIncome.removeAttribute('aria-required'); } // Reset validation messages on switch ['taxableErr','grossErr','preTaxErr','itemizedErr'].forEach(id=>{ const el = $('#'+id); if(el) el.textContent = ''; }); }

('input[name="deductionMode"]').forEach(r => r.addEventListener('change', ()=>{ if(!modeGross.checked) return; const dm = getDeductionMode(); if(dm === 'standard'){ itemizedWrap.hidden = true; stdDeductionWrap.hidden = false; }else{ itemizedWrap.hidden = false; stdDeductionWrap.hidden = true; } })); // Standard deduction calc (for estimator only) function computeStandardDeduction(){ const year = taxYear.value; const fs = getStatus(); let sd = 0; if(year === '2024'){ sd = STD_DED_2024[fs] ?? 0; } standardDeduction.value = sd.toFixed(2); } taxYear.addEventListener('change', computeStandardDeduction);

For a given filing status with bracket set B = { (r_i, L_i, U_i) }, where r_i is the marginal rate, L_i and U_i are the lower and upper bounds, Nebraska tax T on taxable income x is: \( T(x) \;=\; \max\!\Bigg(0, \sum_i r_i \cdot \max\big(0,\; \min(x,\; U_i) - L_i\big) \Bigg) \;-\; C \) with credits C capped so that T(x) ≥ 0. If you estimate taxable income from gross: \( \text{TaxableIncome} \;=\; \max\big(0,\; \text{Gross} - \text{PreTax} - \text{Deduction}\big) \) Effective rate: \( \text{Effective} \;=\; \begin{cases} \dfrac{T(x)}{x} & x \gt 0\\ 0 & x = 0 \end{cases} \)