*{
    margin: 0;
    padding: 0;
}

h1{
    margin-top: 30px;
    text-align: center;
    font-weight: 700;
}

h4{
    margin-top: 10px;
    text-align: center;
    font-size: 1rem;
    color: gray;
}

.contents{
    width: 80%;
    margin: auto;
    margin-top: 30px;
    background-color: aliceblue;
    padding: 15px 20px;
    border-radius: 10px;
}

.contents-main{
    width: 80%;
    margin: auto;
    margin-top: 30px;
    padding: 15px 20px;
    border-radius: 10px;
}

.contents div{
    margin-top: 10px;
}

.contents div:first-of-type{
    margin-top: 0px;
}

.contents-main div{
    text-align: center;
    margin-top: 10px;
}

.contents-main div.pre{
    margin-bottom: 30px;
}

.contents-main div:first-of-type{
    margin-top: 0px;
}

.contents-main div:last-of-type{
    margin-bottom: 30px;
}

a{
    text-decoration: none;
}

button a{
    color: inherit;
}

.btnList{
    width: 100%;
    text-align: center;
    margin-top: 30px;
    margin-bottom: 30px;
}

.btnList button{
    margin-left: 10px;
    margin-right: 10px;
}