*{
    margin:0;
    padding:0;
    box-sizing:border-box;
}

body{
    font-family:'Poppins',sans-serif;
    background:linear-gradient(135deg,#0f172a,#1e293b);
    min-height:100vh;
    display:flex;
    justify-content:center;
    align-items:center;
    padding:20px;
}

.calculadora{
    width:100%;
    max-width:520px;
    background:#ffffff;
    border-radius:25px;
    padding:35px;
    box-shadow:0 15px 40px rgba(0,0,0,.25);
    animation:fadeIn .5s ease;
    position:relative;
    overflow:hidden;
}

.calculadora::before{
    content:'';
    position:absolute;
    top:0;
    left:0;
    width:100%;
    height:6px;
    background:linear-gradient(90deg,#2563eb,#0ea5e9);
}

@keyframes fadeIn{
    from{
        opacity:0;
        transform:translateY(20px);
    }
    to{
        opacity:1;
        transform:translateY(0);
    }
}

.logo{
    text-align:center;
    margin-bottom:15px;
}

.logo img{
    width:95px;
    height:auto;
    object-fit:contain;
    filter:drop-shadow(0 5px 10px rgba(0,0,0,.15));
}

h1{
    text-align:center;
    font-size:30px;
    color:#0f172a;
    margin-bottom:10px;
    font-weight:700;
}

.subtitulo{
    text-align:center;
    color:#64748b;
    margin-bottom:30px;
    font-size:14px;
}

label{
    display:block;
    margin-bottom:8px;
    color:#334155;
    font-weight:600;
}

.input-group{
    position:relative;
    margin-bottom:22px;
}

.input-group span{
    position:absolute;
    left:15px;
    top:50%;
    transform:translateY(-50%);
    color:#2563eb;
    font-weight:700;
    font-size:18px;
}

input{
    width:100%;
    padding:15px 15px 15px 45px;
    border:2px solid #cbd5e1;
    border-radius:14px;
    font-size:18px;
    transition:.3s;
    background:#f8fafc;
}

input:focus{
    border-color:#2563eb;
    background:#fff;
    outline:none;
    box-shadow:0 0 0 4px rgba(37,99,235,.12);
}

.botones{
    display:grid;
    grid-template-columns:1fr 1fr;
    gap:15px;
    margin-bottom:25px;
}

button{
    padding:15px;
    border:none;
    border-radius:14px;
    font-size:15px;
    font-weight:600;
    cursor:pointer;
    transition:.3s;
}

.btn-primary{
    background:#2563eb;
    color:#fff;
}

.btn-primary:hover{
    background:#1d4ed8;
    transform:translateY(-2px);
}

.resultado{
    background:#f8fafc;
    border-radius:20px;
    padding:25px;
    border:1px solid #e2e8f0;
}

.resultado h2{
    font-size:22px;
    margin-bottom:20px;
    color:#0f172a;
    text-align:center;
}

.item{
    display:flex;
    justify-content:space-between;
    align-items:center;
    margin-bottom:15px;
    padding-bottom:12px;
    border-bottom:1px dashed #cbd5e1;
}

.item:last-child{
    border:none;
    margin-bottom:0;
}

.item span{
    font-size:17px;
}

.valor{
    font-weight:700;
    color:#2563eb;
}

.footer{
    text-align:center;
    margin-top:25px;
    font-size:13px;
    color:#94a3b8;
}

.footer strong{
    color:#0f172a;
}

@media(max-width:600px){

    .calculadora{
        padding:25px;
    }

    .botones{
        grid-template-columns:1fr;
    }

}