*{
    box-sizing: border-box;
}

body{
    font-family: sans-serif;
    background-color: #000;
    font-size: 15px;
    line-height: 1.5;
    padding: 0;
    margin: 0;
}

.container{
    width: 520px;
    max-width: 95%;
    height: auto;
    min-height: 100px;
    margin: 100px auto;
    background-color: #000;
    border-radius: 5px;
    border: 1px solid #0ef;
    box-shadow: inset 0 0 0.5em 0 #0ef, 0 0 0.5em 0 #0ef;
}

/* Title */
.base h4{
    font-size: 34px;
    text-align: center;
    font-weight: normal;
    margin-top: 0px;
    color:#0ef;
    box-shadow: 0px 2px #bababa;
    padding-bottom: 10px;
}

/* Input blocks container */
.form-blocks {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
}

/* Each block */
.block{
    width: 135px;
    padding: 5px 10px;
    margin-left: 20px;
    margin-bottom: 20px;
    display: inline-block;
}

/* Labels */
p.title{
    font-size: 20px;
    text-align: left;
    font-weight: normal;
    line-height: 0.5;
    letter-spacing: 0.5px;
    word-spacing: 2.7px;
    color: #0ef;
}

/* Input fields (text or number) */
input[type="text"],
input[type="number"]{
    width: 140px;
    margin: auto;
    outline: none;
    min-height: 50px;
    border: 2px solid #0ef;
    padding: 12px;
    background-color: #111;
    border-radius: 10px;
    color: #fff;
    font-size: 17px;
    text-align: center;
    transition: border 0.1s ease, box-shadow 0.1s ease;
}

/* Remove number arrows/spinners */
input[type=number]::-webkit-inner-spin-button,
input[type=number]::-webkit-outer-spin-button {
    -webkit-appearance: none;
    margin: 0;
}
input[type=number] {
    -webkit-appearance: textfield;
    -moz-appearance: textfield;
    appearance: textfield;
}

/* Focus highlight */
input[type="text"]:focus,
input[type="number"]:focus {
    border: 3px solid #0ef;  
    box-shadow: 0 0 10px #0ef; 
    outline: none;
}

/* Submit Button */
.submit-button {
    text-align: center;
}

input[type=button]{
    width: 140px;
    height: 50px;
    align-items: center;
    margin-top: 5%;
    font-size: 2em;
    cursor: pointer;
    background-color: #0ef;
    color:  #fff;
    border: 1px solid #0ef;
    padding: 5px;
    border-radius: 0.25em;
    box-shadow: inset 0 0 0.5em 0 #0ef, 0 0 0.5em 0 #0ef;
    transition: box-shadow 0.2s ease, color 0.2s ease;
}

input[type=button]:hover{
    color: #000;
    box-shadow: inset 0 0 1.5em 0 #0ef, 0 0 0.5em 0 #fff;
}

/* Age Output */
#age{
    padding: 20px;
    overflow: hidden;
    font-size: 23px;
    font-weight: normal;
    line-height: 1.5;
    word-spacing: 2.7px;
    color: #fff;
}

/* Responsive adjustments */
@media (max-width: 480px){
    .form-blocks {
        flex-direction: column;
        align-items: center;
    }

    .block {
        width: 90%;
        margin-left: 0;
        padding: 0;
    }

    input[type="text"],
    input[type="number"] {
        width: 100%;
    }

    input[type=button] {
        width: 100%;
    }

    .base h4 {
        font-size: 28px;
    }
}