Imagen de como se ve en el navegador:

Codigo en de mi editor:
@import url(‘https://fonts.googleapis.com/css2?family=Ubuntu:wght@300&display=swap’);
* {
margin: 0;
padding: 0;
box-sizing: border-box;
}
:root {
–font: ubuntu;
–main-color: rgb(54, 172, 250);
–secundary-color: rgb(12, 13, 80);
}
.wrapper_calculator {
margin: 0;
padding: 0;
width: 100%;
min-width: 250px;
display: flex;
justify-content: center;
}
.box_calculator {
width: 100%;
min-width: 250px;
padding: 20px;
}
.paypal_fees {
display: flex;
flex-wrap: wrap;
justify-content: center;
}
.paypal_fees span {
margin: 7px;
font-size: 30px;
color: var(–main-color);
}
.label_fees {
width: 100%;
font-size: 20px;
font-weight: bold;
display: flex;
align-items: center;
margin-bottom: 20px;
}
.paypal_fees input {
width: 63px;
padding: 5px;
background-color: var(–secundary-color);
border-radius: 5px;
color: white;
font-weight: bold;
font-family: var(–font), Arial, Helvetica, sans-serif;
font-size: 18px;
text-align: center;
margin: 3px;
border: none;
border-left: 5px solid var(–main-color);
border-right: 5px solid var(–main-color);
}
input.inputs {
display : block ;
border :1 px solid rgba (0 ,0 ,0 ,0.150) ;
width :100 % ;
padding :7 px ;
font-size :16 px ;
font-family : var (–font) , Arial , Helvetica , sans-serif ;
font-weight : bold ;
outline : none ;
border-radius :7 px ;
border-left :5 px solid var (–main-color) ;
border-right :5 px solid var (–main-color) ;
margin-bottom :3 px ;
text-align : center ;
}
.inputs.disabled {
background-color : var (–secundary-color) ;
color : white ;
}
.title_fees {
display : flex ;
margin-bottom :20 px ;
min-height :80 px ;
}
.title_icon {
min-height :80 px ;
min-width :80 px ;
background-color : var (–secundary-color) ;
border-radius :10 px0 px0 px10 px ;
}
.box_tip {
padding :10 px ;
line-height :18 px ;
max-width :500 px ;
background-color : var (–main-color) ;
color : rgb (255 ,255 ,255) ;
font-family : var (–font) , Arial , Helvetica , sans-serif ;
font-weight : bold ;
display : flex ;
align-items : center ;
border-radius :0 px10 px10 px0 px ;
}
.paypal_fees label {
width :100 % ;
display : flex ;
justify-content : center ;
font-family : var (–font) , Arial , Helvetica , sans-serif ;
font-weight : bold ;
}
.box_send_receive label {
text-align : center ;
margin-top :5 px ;
width :100 % ;
}
.box_send_receive span {
font-size :20 px ;
margin-left :3 px ;
}
.calculator_send , .calculator_receive {
width :35 % ;
border-radius :20 px ;
display : flex ;
flex-direction : column ;
align-items : center ;
padding :20 px30 px ;
min-width :100 px ;
font-family : var (–font) , Arial , Helvetica , sans-serif ;
box-shadow :0 px0 px10 px1 px rgba (0 ,0 ,0 ,0.082) ;
margin :10 px ;
}
.box_send_receive {
display : flex ;
flex-wrap : wrap ;
}
.title_icon , .info {
display : flex ;
justify-content : center ;
align-items : center ;
}
.info {
width :40 px ;
height :40 px ;
background-color : var (–main-color) ;
border-radius :50 % ;
font-size :30 px ;
animation : info 1 s infinite ease ;
color : var (–secundary-color) ;
font-family : Impact , ‘Arial Narrow Bold’ , sans-serif ;
}
@keyframes info {
0 % {
width :40 px ;
height :40 px ;
}
50 % {
width :50 px ;
height :50 px ;
font-size :45 px ;
}
100 % {
width :40 px ;
height :40 px ;
}
}
@media screen and (max-width: 640px) {
.calculator_send, .calculator_receive {
flex-wrap: wrap;
width: 100%;
}
}
@media screen and (max-width: 356px) {
.label_fees {
font-size: 14px;
}
.paypal_fees span {
font-size: 14px;
}
.label_fees input {
font-size: 14px;
width: 50px;
}
}
@media screen and (max-width: 286px) {
.label_fees {
font-size: 12px;
}
.paypal_fees span {
font-size: 10px;
}
.label_fees input {
font-size: 12px;
width: 45px;
}
}
@media screen and (max-width: 262px) {
.label_fees {
font-size: 10px;
}
.label_fees input {
font-size: 10px;
width: 40px;
}
}
</style>
<main class=»wrapper_calculator»>
<form class=»box_calculator»>
<div class=»paypal_fees»>
<div class=»title_fees»>
<div class=»title_icon»>
<div class=»info»>!</div>
</div>
<div class=»box_tip»>
<p class=»tip»>
¡Con esta calculadora podrá saber cuanto llega de un envio y/o saber cuanto enviar
para que llegue un monto específico!
</p>
</div>
</div>
<label class=»label_fees» for=»»>PayPal Fee:
<input type=»text» id=»porcentage» class=»fees» placeholder=»5.4%» value=»5.4″ disabled>%<span>+</span>$
<input type=»text» id=»comision» class=»fees» placeholder=»$0.30″ value=»0.30″ disabled>
</label>
</div>
<div class=»box_send_receive»>
<div class=»calculator_send»>
<label for=»send»>Si Envia:
<input type=»text» id=»send» class=»inputs» placeholder=»Digite un monto»>
</label>
<label for=»»>Comisión:
<input type=»text» id=»send_fees» class=»inputs disabled fees» disabled>
</label>
<label for=»»>Se Recibe:
<input type=»text» id=»send_recieve» class=»inputs disabled» disabled>
</label>
<label for=»»>En Bolívares:
<input type=»text» id=»send_bolivares» class=»inputs disabled» disabled>
</label>
</div>
<div class=»calculator_receive»>
<label for=»send_2″>Para Recibir:
<input type=»text» id=»send_2″ class=»inputs» placeholder=»Digite un monto»>
</label>
<label for=»»>Comisión:
<input type=»text» id=»send_fees_2″ class=»inputs disabled fees» disabled>
</label>
<label for=»»>Debe Enviar:
<input type=»text» id=»send_recieve_2″ class=»inputs disabled» disabled>
</label>
<label for=»»>En Bolívares:
<input type=»text» id=»send_bolivares_2″ class=»inputs disabled» disabled>
</label>
</div>
</div>
</form>
</main>
<script>
const porcentagePp = parseFloat(document.querySelector(‘#porcentage’).value);
const comisionPp = parseFloat(document.querySelector(‘#comision’).value);
const send = document.querySelector(‘#send’);
const send_2 = document.querySelector(‘#send_2’);
// Tasa de cambio en bolívares
const tasaCambio = 26.40;
const getSend = () => {
const inputAmount = document.querySelector(‘#send’);
const sendFees = document.querySelector(‘#send_fees’);
const send_recive = document.querySelector(‘#send_recieve’);
const send_bolivares = document.querySelector(‘#send_bolivares’);
const newInputAmount = inputAmount.value.replace(‘,’, ‘.’);
const amount = parseFloat(newInputAmount);
const fixedAmount = amount.toFixed(2);
const menosPorcentage = (porcentagePp * fixedAmount) / 100;
const menosPorcentageFixed = menosPorcentage.toFixed(2)
const soloFee = menosPorcentage + comisionPp;
const soloFeeFixed = soloFee.toFixed(2)
const menosComision = fixedAmount – menosPorcentageFixed – comisionPp;
const menosComisionFixed = menosComision.toFixed(2)
const result = menosComisionFixed;
if ( !Number(fixedAmount) || fixedAmount == «» || inputAmount.value.length > 20) {
inputAmount.value = «»;
sendFees.value = «»;
send_recieve.value = «»;
send_bolivares.value = «»;
} else {
sendFees.value = soloFeeFixed;
send_recieve.value = result;
send_bolivares.value = (result * tasaCambio).toFixed(2);
}
}
const getSend_2 = () => {
const inputAmount_2 = document.querySelector(‘#send_2’);
const sendFees_2 = document.querySelector(‘#send_fees_2’);
const send_recieve_2 = document.querySelector(‘#send_recieve_2’);
const send_bolivares_2 = document.querySelector(‘#send_bolivares_2’);
const newInputAmount_2 = inputAmount_2.value.replace(‘,’, ‘.’);
const amount_2 = parseFloat(newInputAmount_2);
const fixedAmount_2 = parseFloat(amount_2.toFixed(2));
const masProcentage = (100 * (comisionPp + fixedAmount_2) / ((0-porcentagePp) + 100))
const masProcentageFixed = masProcentage.toFixed(2);
const soloFee_2 = masProcentageFixed – fixedAmount_2;
const soloFeeFixed_2 = parseFloat(soloFee_2.toFixed(2));
const feeMasMonto = parseFloat(fixedAmount_2 + soloFeeFixed_2);
const feeMasMontoFixed = feeMasMonto.toFixed(2);
const result_2 = feeMasMontoFixed;
if ( !Number(fixedAmount_2) || fixedAmount_2 == «» || inputAmount_2.value.length > 20) {
inputAmount_2.value = «»;
sendFees_2.value = «»;
send_recieve_2.value = «»;
send_bolivares_2.value = «»;
} else {
sendFees_2.value = soloFeeFixed_2.toFixed(2);
send_recieve_2.value = result_2;
send_bolivares_2.value = (result_2 * tasaCambio).toFixed(2);
}
}
send.addEventListener(‘keyup’, getSend)
send_2.addEventListener(‘keyup’, getSend_2)
</script>