.demo-notice {
    color: red;
    font-size: 90%;
}

.mb-4 {
    margin-bottom: 1rem;
}

.back-to-menu-btn {
    position: absolute;
    right: 30px;
    top: 80px;
}

.content-inner {
    position: relative;
}

.topmenu {
    text-align: center;
}

.topmenu > div {
    margin-top: 2em;
}

.topmenu .m-btn-common {
    width: 100%;
}

.topmenu img {
    border: solid 1px gray;
    display: block;
    margin-left: auto;
    margin-right: auto;
    margin-bottom: 1em;
    box-shadow: 4px 4px 4px #aaa;
}

.m-table-common.index .no {
    text-align: right;
    width: 5em;
}

.m-table-common.index .button {
    text-align: center;
    width: 10em;
}

.m-table-common.graph .no {
    width: 8em;
    text-align: right;
}

.m-table-common.graph td, .m-table-common.graph th {
    text-align: center;
}

caption {
    text-align: left;
}

.rittai .thumbnail {
    text-align: center;
    margin-top: 1em;
    margin-bottom: 2em;
    border: solid 1px #aaa;
    border-radius: 0.5em;
    padding: 1em;
}

.rittai .thumbnail .title {
    font-size: 1.2em;
    margin-top: 0.5em;
}

.rittai .thumbnail .m-btn-common {
    width: 40%;
    margin-left: auto;
    margin-right: auto;
}

.w-auto {
    width: auto;
}

.zuhan-notice {
    margin-top: 0 !important;
}

.zuhan-index-btns {
    margin-top: 0 !important;
}

.zuhan-index {
    margin-top: 0.5em !important;
}

.zuhan-index .chapter-name {
    margin: 1em 0 0 0;
    font-size: 110%;
    border-bottom: dotted 1px #777;
}

.zuhan-index a {
    color: #00AFEC;
}

.zuhan-index a:hover {
    text-decoration: underline;
}

.images {
    display: flex;
    flex-wrap: wrap;
    align-items: flex-end;
}

.images .img-box {
    width: 200px;
    margin: 0 1em 2em 1em;
    text-align: center;
}

.img-box img {
    border: solid 1px #aaa;
    max-height: 250px;
}

.img-btns {
    display: flex;
    justify-content: center;
    margin-top: 0.5em;
}

.img-btns.btn-center {
    justify-content: center;
}

.img-btns .m-btn-common {
    width: 45%;
}

.d-none {
    display: none !important;
}

.word-index-table .m-btn-simple {
    width: 16em;
}