/* ===========================
   RESET
=========================== */

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

body{

    font-family:'Segoe UI',Arial,sans-serif;

    background:#eef5fb;

    color:#333;

    padding:30px 15px;

}

/* ===========================
   CONTAINER
=========================== */

.container{

    max-width:700px;

    margin:auto;

}

/* ===========================
   CARD
=========================== */

.card{

    background:#fff;

    border-radius:16px;

    padding:35px;

    box-shadow:0 8px 25px rgba(0,0,0,.12);

}

/* ===========================
   TÍTULOS
=========================== */

h1{

    text-align:center;

    color:#0077c8;

    font-size:2rem;

    margin-bottom:15px;

}

h1 i{

    margin-right:8px;

}

.descricao{

    text-align:center;

    color:#666;

    line-height:1.6;

    margin-bottom:35px;

}

/* ===========================
   CAMPOS
=========================== */

.campo{

    margin-bottom:22px;

}

.campo label{

    display:block;

    margin-bottom:8px;

    font-weight:600;

    color:#005b96;

}

.campo input,
.campo select{

    width:100%;

    padding:13px 15px;

    border:1px solid #cfd8dc;

    border-radius:8px;

    font-size:1rem;

    transition:.3s;

    outline:none;

}

.campo input:focus,
.campo select:focus{

    border-color:#0077c8;

    box-shadow:0 0 10px rgba(0,119,200,.20);

}

/* ===========================
   BOTÃO
=========================== */

button{

    width:100%;

    border:none;

    border-radius:10px;

    background:#0077c8;

    color:#fff;

    font-size:1.1rem;

    font-weight:bold;

    padding:15px;

    cursor:pointer;

    transition:.3s;

}

button:hover{

    background:#005d9b;

}

/* ===========================
   RESULTADO
=========================== */

.resultado{

    display:none;

    margin-top:35px;

    padding:30px;

    border-radius:12px;

    background:#f1f9ff;

    border-left:6px solid #0077c8;

    text-align:center;

}

.resultado h2{

    color:#005b96;

    margin-bottom:18px;

}

#valorBTU{

    font-size:2rem;

    font-weight:bold;

    color:#0077c8;

}

/* ===========================
   OBSERVAÇÃO
=========================== */

.observacao{

    margin-top:30px;

    padding:18px;

    background:#fff8e8;

    border-left:5px solid #ffc107;

    border-radius:8px;

    color:#555;

    line-height:1.6;

}

.observacao strong{

    display:block;

    margin-bottom:8px;

}

/* ===========================
   RESPONSIVO
=========================== */

@media(max-width:768px){

.card{

    padding:25px;

}

h1{

    font-size:1.7rem;

}

#valorBTU{

    font-size:1.7rem;

}

button{

    font-size:1rem;

}

}