script.js

// Tab switching
document.querySelectorAll('.tab-btn').forEach(btn => {
    btn.addEventListener('click', () => {
        const tabName = btn.dataset.tab;
        
        // Remove active class from all tabs and contents
        document.querySelectorAll('.tab-btn').forEach(b => b.classList.remove('active'));
        document.querySelectorAll('.tab-content').forEach(c => c.classList.remove('active'));
        
        // Add active class to clicked tab and corresponding content
        btn.classList.add('active');
        document.getElementById(tabName).classList.add('active');
    });
});

// Length conversion
const lengthRatios = {
    mm: 0.001,
    cm: 0.01,
    m: 1,
    km: 1000,
    inch: 0.0254,
    ft: 0.3048,
    yard: 0.9144,
    mile: 1609.34
};

function convertLength() {
    const input = parseFloat(document.getElementById('length-input').value);
    const fromUnit = document.getElementById('length-from').value;
    const toUnit = document.getElementById('length-to').value;
    
    if (isNaN(input)) {
        document.getElementById('length-output').value = '';
        return;
    }
    
    const meters = input * lengthRatios[fromUnit];
    const result = meters / lengthRatios[toUnit];
    document.getElementById('length-output').value = result.toFixed(6);
}

document.getElementById('length-input').addEventListener('input', convertLength);
document.getElementById('length-from').addEventListener('change', convertLength);
document.getElementById('length-to').addEventListener('change', convertLength);

// Weight conversion
const weightRatios = {
    mg: 0.000001,
    g: 0.001,
    kg: 1,
    ton: 1000,
    oz: 0.0283495,
    lb: 0.453592
};

function convertWeight() {
    const input = parseFloat(document.getElementById('weight-input').value);
    const fromUnit = document.getElementById('weight-from').value;
    const toUnit = document.getElementById('weight-to').value;
    
    if (isNaN(input)) {
        document.getElementById('weight-output').value = '';
        return;
    }
    
    const kg = input * weightRatios[fromUnit];
    const result = kg / weightRatios[toUnit];
    document.getElementById('weight-output').value = result.toFixed(6);
}

document.getElementById('weight-input').addEventListener('input', convertWeight);
document.getElementById('weight-from').addEventListener('change', convertWeight);
document.getElementById('weight-to').addEventListener('change', convertWeight);

// Temperature conversion
function convertTemperature() {
    const input = parseFloat(document.getElementById('temp-input').value);
    const fromUnit = document.getElementById('temp-from').value;
    const toUnit = document.getElementById('temp-to').value;
    
    if (isNaN(input)) {
        document.getElementById('temp-output').value = '';
        return;
    }
    
    let celsius;
    if (fromUnit === 'c') {
        celsius = input;
    } else if (fromUnit === 'f') {
        celsius = (input - 32) * 5/9;
    } else if (fromUnit === 'k') {
        celsius = input - 273.15;
    }
    
    let result;
    if (toUnit === 'c') {
        result = celsius;
    } else if (toUnit === 'f') {
        result = celsius * 9/5 + 32;
    } else if (toUnit === 'k') {
        result = celsius + 273.15;
    }
    
    document.getElementById('temp-output').value = result.toFixed(4);
}

document.getElementById('temp-input').addEventListener('input', convertTemperature);
document.getElementById('temp-from').addEventListener('change', convertTemperature);
document.getElementById('temp-to').addEventListener('change', convertTemperature);

// Swap units function
function swapUnits(type) {
    const fromSelect = document.getElementById(`${type === 'temperature' ? 'temp' : type}-from`);
    const toSelect = document.getElementById(`${type === 'temperature' ? 'temp' : type}-to`);
    
    const temp = fromSelect.value;
    fromSelect.value = toSelect.value;
    toSelect.value = temp;
    
    // Trigger conversion
    if (type === 'length') convertLength();
    else if (type === 'weight') convertWeight();
    else if (type === 'temperature') convertTemperature();
}