html, body, main {
    height: 100%;
    /*    background-color: #f2f2f2;*/
    letter-spacing: 0.02em;
}

header, footer {
    background-color: #163549;
}

header {
    height: 70px;
}

footer {
    height: 40px;
}

main > .container {
    padding: 70px 0px 40px;
}

#gender:required:invalid {
    color: gray;
}

#gender option[value=""] {
    display: none;
}

#landing .card {
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border-radius: 15px;
    overflow: hidden;
}

#landing .card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(255, 78, 121, 0.2) !important;
}