/* ----------------- General ----------------- */

body{
    font-family: Arial, sans-serif;
    margin:0;
    background:#f4f6f9;
    text-align:center;
    color:#333;
}

/* ----------------- Header ----------------- */

header{
background: linear-gradient(90deg, #3498db, #2980b9);
color:white;
padding:20px 0;
position:sticky;
top:0;
z-index:1000;
transition:padding 0.3s ease;
}

header.header-small{
padding:8px 0;
}
/* ----------------- Navegación ----------------- */

nav{
    margin-top:10px;
}

nav a{
    color:white;
    margin:0 15px;
    text-decoration:none;
    font-weight:bold;
    transition:0.3s;
}

nav a:hover{
    color:#f1c40f;
}

/* ----------------- Main ----------------- */

main{
max-width:900px;
margin:auto;
padding:40px 20px;
}
/* ----------------- Herramientas / Tarjetas ----------------- */

.tools{
    display:flex;
    flex-wrap:wrap;
    justify-content:center;
    gap:20px;
    margin-top:30px;
}

.tools a{
    display:flex;
    flex-direction:column;
    align-items:center;
    justify-content:center;
    width:200px;
    padding:20px;
    background:white;
    border-radius:15px;
    text-decoration:none;
    color:#333;
    font-weight:bold;
    box-shadow:0 10px 20px rgba(0,0,0,0.15);
    transition:transform 0.3s, box-shadow 0.3s;
    text-align:center;
}

.tools a:hover{
    transform:translateY(-5px) scale(1.05);
    box-shadow:0 15px 25px rgba(0,0,0,0.25);
    background:#3498db;
    color:white;
}

.tools i{
    margin-bottom:10px;
    color:#3498db;
    font-size:30px;
}

/* ----------------- Botones ----------------- */

button{
    background:#3498db;
    color:white;
    border:none;
    padding:10px 20px;
    border-radius:8px;
    cursor:pointer;
    font-weight:bold;
    transition:0.3s;
    margin:5px;
}

button:hover{
    background:#2980b9;
    transform:scale(1.05);
}

/* ----------------- Inputs ----------------- */

input{
    padding:10px;
    margin:5px 0;
    border-radius:6px;
    border:1px solid #ccc;
    width:150px;
    text-align:center;
    transition:0.3s;
}

input:focus{
    border-color:#3498db;
    outline:none;
    box-shadow:0 0 5px rgba(52,152,219,0.5);
}

/* ----------------- Filas para calculadoras ----------------- */

.fila{
    display:flex;
    flex-wrap:wrap;
    justify-content:center;
    align-items:center;
    gap:10px;
    margin-bottom:10px;
}

/* ----------------- Resultado ----------------- */

#resultado{
    margin-top:20px;
    font-size:1.5rem;
    font-weight:bold;
}

/* ----------------- Responsive ----------------- */

@media (max-width:768px){

    header h1{
        font-size:1.4rem;
    }

    nav{
        display:flex;
        flex-wrap:wrap;
        justify-content:center;
    }

    nav a{
        margin:5px 8px;
        font-size:14px;
    }

    main{
        padding:20px 15px;
    }

    .tools{
        flex-direction:column;
        align-items:center;
    }

    .tools a{
        width:90%;
    }

    .fila{
        flex-direction:column;
    }

    input{
        width:90%;
    }

    button{
        width:90%;
    }

}
footer{
background:#2c3e50;
color:white;
text-align:center;
padding:25px;
margin-top:50px;
font-size:14px;
}

footer a{
color:#f1c40f;
text-decoration:none;
margin:0 5px;
}

footer a:hover{
text-decoration:underline;
}


/* BARRA SUPERIOR */

.header-bar{
display:flex;
align-items:center;
justify-content:center;
position:relative;
}