* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'gilroy';
}
body {
    height: 100%;
    width: 100%;
    background-color: #63ADF2;
    display: flex;
    justify-content: center;
    margin-top: 50px;
}
.bmr-calculator {
    height: 80vh;
    width: 40vw;
    background-color: aliceblue;
    box-shadow: 0 4px 8px -3px rgba(0, 0, 0, 0.5);
    border-radius: 10px;

}
@media (max-width: 600px) {
    .bmr-calculator {
        height: 65vh;
        width: 90vw;
    }
    .bmr-calculator h2 {
        height: 5%;
        padding-top: 10px;
    }
}
.bmr-calculator h2 {
    height: 10%;
    font-size: 150%;
    color: white;
    background-color: #222;
    text-align: center;
    padding-top: 15px;
    border-radius: 10px 10px 0 0;
}
.bmr-calculator form {
    height: 50vh;
    display: flex;
    flex-direction: column;
    gap: 10px;
    border: 1px solid black;
    border-radius: 5px;
    margin: 15px 10px;
    padding: 5px 5px;
    background-color: #A7CCED;
}
.bmr-calculator form .age-section {
    height: 20%;
}
.bmr-calculator form .gender {
    height: 20%;
}
.bmr-calculator form .height-section {
    height: 20%;
}
.bmr-calculator form .weight-section {
    height: 20%;
}
@media (max-width: 600px) {
    .bmr-calculator form {
        height: 40vh;
    }
}
.bmr-calculator form h3 {
    font-size: 0.9em;
    margin: 6px 3px;
    text-transform: uppercase;
}
.bmr-calculator form h3 #unit {
    font-size: 1em;
    text-transform: lowercase;
    font-weight: 200;
}
.bmr-calculator form input[type='text'] {
    width: 70%;
    padding: 4px 10px;
    font-size: 1em;
    font-weight: bold;
    border: 1px solid #d5dbdd;
    border-radius: 5px;
    margin-left: 5px;
} 
.bmr-calculator form input[type='text'].invalid {
    border: 2px solid red;
}
.bmr-calculator form .gender #male {
    margin-left: 5px;  
}
.bmr-calculator form .gender #female {
    margin-left: 5px;  
}
.bmr-calculator .result {
    height: 15vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}
.bmr-calculator .result .calculate-btn {
    padding: 8px 24px;
    font-size: 18px;
    font-weight: 100;
    text-transform: uppercase;
    background-color: #333;
    color: #fff;
    cursor: pointer;
    margin-bottom: 10px;
    border-radius: 5px;
}
.bmr-calculator .result .calories {
    color: green;
    font-size: 38px;
    font-weight: 800;
    margin-right: 7px;
    vertical-align: middle;
} 
.bmr-calculator .result {
    text-align: center;
    color: #4e4e4e;
    font-size: 1.2em;
}
.bmr-calculator .result .error-msg {
    color: red;
    font-size: 0.9em;
    padding-bottom: 20px;
    display: none;
}
.bmr-calculator .result .error-msg.active {
    display: block;
}