style.css

/* Import Google font - Poppins */
@import url("https://fonts.googleapis.com/css2?family=Poppins:wght@200;300;400;500;600;700&display=swap");

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: "Poppins", sans-serif;
}

body {
    min-height: 150vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
    background: rgb(130, 106, 251);
}

.container {
   position: relative;
   max-width: 700px;
   width: 100%;
   background: #fff;
   padding: 25px;
   border-radius: 8px;
   box-shadow: 0 0 15px rgba(0, 0, 0, 0.1);
}

.container header {
   font-size: 1.5rem;
   color: #333;
   font-weight: 500;
   text-align: center;
}

.container .row {
  margin-top: 30px;
}

.row .input-box {
    width: 100%;
    margin-top: 20px;
}

.input-box label {
    color: #333;
}

.row :where(.input-box input, .select-box) {
    position: relative;
    height: 50px;
    width: 100%;
    outline: none;
    font-size: 1rem;
    color: #707070;
    margin-top: 8px;
    border: 1px solid #ddd;
    border-radius: 6px;
    padding: 0 15px;
}

.input-box input:focus {
    box-shadow: 0 1px 0 rgba(0, 0, 0, 0.1);
}

.row .column {
    display: flex;
    column-gap: 15px;
}

.row .gender-box {
    margin-top: 20px;
}

.gender-box h3 {
    color: #333;
    font-size: 1rem;
    font-weight: 400;
    margin-bottom: 8px;
}

.row :where(.gender-option, .gender) {
    display: flex;
    align-items: center;
    column-gap: 50px;
    flex-wrap: wrap;
}

.row .gender {
    column-gap: 5px;
}

.gender input {
    accent-color: rgb(130, 106, 251);
}

.row :where(.gender input, .gender label) {
    cursor: pointer;
}

.gender label {
    color: #707070;
}

.address :where(input, .select-box) {
    margin-top: 15px;
}

.select-box select {
    height: 100%;
    width: 100%;
    outline: none;
    border: none;
    color: #707070;
    font-size: 1rem;
}

.row button {
    height: 55px;
    width: 100%;
    color: #fff;
    font-size: 1rem;
    font-weight: 400;
    margin-top: 30px;
    border: none;
    cursor: pointer;
    transition: all 0.2s ease;
    background: rgb(130, 106, 251);
}
    .row button:hover {
        background: rgb(88, 56, 250);
    }
/*Responsive*/
@media screen and (max-width: 500px) {
    .row .column {
        flex-wrap: wrap;
    }

    .row :where(.gender-option, .gender) {
        row-gap: 15px;
    }
}