body{font-family:Arial}
.calculator-container{
max-width:420px;
margin:auto;
padding:32px;
background:#fff;
border-radius:18px;
box-shadow:0 8px 24px rgba(0,0,0,.15)
}
input,select,button{
width:100%;
padding:12px;
margin:10px 0;
border-radius:8px;
border:1px solid #ccc
}
button{
background:#ff6a00;
color:#fff;
border:none;
font-weight:bold;
cursor:pointer
}