.challenge {
    margin: 20px;
    padding: 10px;
    
    border: 1px solid whitesmoke;
    background-color: darkslategray;
    color: whitesmoke;

    width: 90%;
}

header {
    position: fixed;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;

    width: 100%;
    height: 15vh;
    max-height: 150px;

    background-color: darkslategrey;

}

header h1 {
    color: whitesmoke;

    text-decoration: none;
}

header h1 a {
    color: whitesmoke;

    text-decoration: none;
}

body {
    min-height: 100vh;

    margin: 0;
    padding: 0;

    background-color: slategray;
}

.day-container, #challenges-container {
    color: slategray;

    height: 100%;
    width: 100%;

    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;

    padding-top:15vh;
}

.day-container a {
margin: 2.5% 1.5% 0 1.5%;

    height: 15vh;
    width: 25%;

    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;

    background-color: darkslategray;
    color: whitesmoke;

    border: .5vh solid whitesmoke;

    text-decoration: none;
}