The page don't refresh . Why?

I tried to built this javascript calculator, but there is a problem. When I enter values it's works good. But the problem is when I refresh the page, she's doesn't refreshed; she only saves first values that was entered. Why?

var 
    displayResultBtn = document.querySelector('#calc-btn'),
    backToInputBtn = document.querySelector('#back-input');

var 
    inputPage = document.querySelector('#data-inputs'),
    outputPage = document.querySelector('#data-outputs');

/* ========== Go to Result ========== */
displayResultBtn.addEventListener('click', displayResult);

function displayResult(){

    var 
        coutJour = parseFloat(document.querySelector('#cj-input').value),
        nbrJour = parseInt(document.querySelector('#nj-input').value),
        prime;

    // calcul Base Salary
    slrBase = coutJour * nbrJour;


    if(nbrJour>=25){
        prime = 200;
    }
    else if(nbrJour>=20){
        prime = 150;
    }
    else if(nbrJour>=15){
        prime = 100;
    }
    else if(nbrJour<15){
        prime = 50;
    }

    //calcul Net Salary
    var slrNet = slrBase + prime;

    //display results in his places
    document.querySelector('#slrBase-result').innerHTML = slrBase + " $";
    document.querySelector('#prime-result').innerHTML = prime + " $";
    document.querySelector('#slrNet-result').innerHTML = slrNet + " $",
    document.querySelector('#slrNet-result').style.color = "red";

    // display the result Page
    inputPage.style.display = "none";
    outputPage.style.display = "flex";
}

/* ========== Back to inputs ========== */
backToInputBtn.addEventListener('click', displayInputs);

function displayInputs(){
    outputPage.style.display = "none";
    inputPage.style.display = "initial";
}

*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: sans-serif;
}

body{
    width: 100%;
    height: 100vh;
    display: grid;
    grid-template-rows: 10% 85% 5%;
}


/* ========== Header ========== */
header{
    width: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
    background-color: #a52a2a;
}

header h1{
    font-size: 2.5rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: .05rem;
    color: #fff;
}

main{
    width: 100%;
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
}

/* ========== Input ========== */
#data-inputs{
    display: initial;
    width: 300px;
    height: auto;
    padding: 25px;
}
  
.inputs{
    margin-bottom: 25px;
}

input{
    width: 100%;
    margin-bottom: 15px;
    padding: 5px;
    outline: none;
    border: none;
    border-bottom: 1px solid;
    font-size: 1rem;
    text-align: center;
    background-color: transparent;
}

input::placeholder{
    font-size: 1rem;
    text-align: center;
}

input:focus{
    border-bottom: 2px solid #a52a2a;
}

.btns{
    width: 100%;
    display: flex;
    justify-content: space-between;
}

button{
    padding: 10px;
    outline: none;
    font-size: 1rem;
    font-weight: 600;
    text-transform: uppercase;
    cursor: pointer;
    transition: .3s;
}

button:hover{
    transform: translateY(-2px);
    box-shadow: 0 2px 4px #333333;
}

#calc-btn, .final__btn{
    width: 50%;
    border: none;
    color: #fff;
    background-color: #a52a2a;
}

#reset-btn{
    width: 45%;
    border: 1px solid #a52a2a;
    color: #a52a2a;
    background-color: transparent;
}


/* ========== Output ========== */
#data-outputs{
    width: 400px;
    height: auto;
    display: none;
    flex-direction: column;
    row-gap: 2rem;
    padding: 25px;
}

.outputs{
    background-color: #a52a2a;
}

.result__container{
    display: flex;
    justify-content: space-between;
    margin: 2px;
    padding: 10px;
    font-size: 1.2rem;
    font-weight: 500;
    background-color: #fff;
}

.btn{
    width: 100%;
    display: flex;
    justify-content: center;
}


/* ========== Footer ========== */
footer{
    display: flex;
    justify-content: center;
    align-items: center;
    color: #fff;
    background-color: #a52a2a;  
} 

        <header class="header">
            <h1>Net Salary</h1>
        </header>

        <div class="container">
            <main class="main">
                <div class="data__inputs" id="data-inputs">
                    <div class="inputs">
                        <input type="number" placeholder="Cout Journalier" id="cj-input">
                        <input type="number" placeholder="Nombre jour" id="nj-input">
                    </div>
    
                    <div class="btns">
                        <button type="reset" id="reset-btn">reset</button>
                        <button id="calc-btn">calcul</button>
                    </div>
                </div>
    
                <div class="data__outputs" id="data-outputs">
                    <div class="outputs">
                        <div class="result__container">
                            <span class="output__title">Base Salary :</span>
                            <span id="slrBase-result">0 $</span>
                        </div>
        
                        <div class="result__container">
                            <span class="output__title">Prime :</span>
                            <span id="prime-result">0 $</span>
                        </div>
        
                        <div class="result__container">
                            <span class="output__title">Net Salary :</span>
                            <span id="slrNet-result">0 $</span>
                        </div>
                    </div>
                    <div class="btn">
                        <button type="reset" class="final__btn" id="back-input">OK</button>
                    </div>
                </div>
            </main>
        </div>

        <footer class="footer">
            <p>Copyright &#169; 2020-2021 Aatmane. All rights reserved</p>
        </footer>