*{
    padding:0;
    margin:0;
    box-sizing:border-box;
    text-align:center;
}
html{
    height:100%;
}
body{
    background-color:#272727;
    color:#ffffff;
    min-height:100vh;
}
header{
    text-align:center;
    padding:25px;
    position:sticky;
    top:0;
    background-color: #272727;
}
header a{
    text-decoration:none;
}
main {
    text-align:center;
    background-color:#000000;
    padding:20px;
}
a{
    color:#ffffff;
}
footer{
    background-color:#272727;
    padding:40px;
    flex:1;
}

/* index.htmlを意図 */

main p{
    width:90%;
    margin:0 auto;
}

.buttonField{
    margin:40px auto;
    list-style:none;
}
.linkButton{
    width:300px;
    padding:10px;
    border:2px solid #ffffff;
    border-radius:20px;
    box-shadow: 0px 0px 10px 5px #ffffff;
    margin:0 auto;
    position:relative;
}
.linkButton::after{
    content:"";
    width:100%;
    height:100%;
    background-color:#ffffff;
    opacity:0;
    transition:opacity 0.2s;
    position:absolute;
    top:0;
    left:0;
    pointer-events:none;
}
.linkButton:hover::after{
    opacity:0.3; 
}
.linkButton a{
    display:block;
    text-decoration:none;
    font-size:24px;
    font-weight:bold;
    color:#ffffff;
}
hr{
    margin:20px 0;
}

/* not_foundページを意図 */
.messageField{
    margin:1rem auto;
}
h2{
    margin:0 auto 0.67rem;
}