/* 共通スタイル */
.setCenter {
    text-align: center;
    padding-left: 10px;
    padding-right: 10px;
}

footer {
    text-align: center;
    background-color: #303038;
    color: white;
}

body {
    font-size: 16px;
    margin: 0;
    padding: 0;
    font-family: Arial, sans-serif;
}

body.is-wall {
    background-image: url("../image_dir/wall.png");
    background-size: cover;
    background-attachment: fixed;
    background-position: center;
}

.container {
    display: flex;
    flex-wrap: wrap;
}

.item {
    flex: 1 1 200px;
}

.chapter {
    text-align: center;
    color: #494544;
}

.section {
    text-align: center;
    color: #595959;
    margin-top: 10px;
    margin-bottom: 10px;
}

.image {
    text-align: center;
}

.image img {
    max-width: 80%;
    height: auto;
}

/* リンクのスタイル */

.link_main{
    list-style: none;
    padding-left: 0;
    margin: 20px 150px;
}

a.link_one{
    display:block;
    width: 500px;
    padding: 10px 0px;
    color: white;
    background: #494544;
    text-decoration:none;
    margin:auto;
    text-align:center;
    font-size: 100%;
}

a:hover.link_one{
    background: darkgray;
}

/* ナビゲーションメニューのスタイル */
#menu-toggle {
    display: none;
    background-color: #5a5e64;
    color: white;
    border: none;
    padding: 12px;
    font-size: 18px;
    width: 100%;
    text-align: center;
    cursor: pointer;
}

#nav-menu {
    display: none;
    flex-direction: column;
    align-items: center;
    width: 100%;
    background-color: #5a5e64;
    padding: 0;
    position: absolute;
    top: 60px;
    left: 0;
    z-index: 1000;
    opacity: 0;
    transition: opacity 0.3s ease-in-out;
}

#nav-menu.show {
    display: flex;
    opacity: 1;
}

nav ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

nav ul li {
    width: 100%;
    text-align: center;
    padding: 15px 0;
    border-bottom: 1px solid white;
    font-size: 18px;
}

nav ul li a {
    text-decoration: none;
    color: white;
    display: block;
    width: 100%;
    padding: 10px;
}

nav ul li:hover {
    background: darkgray;
}

/* スマホ向けレイアウト調整 */
@media screen and (max-width: 768px) {
    body {
        font-size: 14px;
        padding: 5px;
    }

    #menu-toggle {
        display: block;
    }

    #nav-menu {
        display: none;
    }

    footer {
        text-align: center;
        padding: 10px 0;
    }

    .link_main{
        margin: 0 30px;
    }

    li.link_one {
        margin-top: 20px;
        margin-bottom: 20px;
    }

    a.link_one{
        width: 90%;
        font-size: 120%;
    }
}

/* PC向けのレイアウト */
@media screen and (min-width: 769px) {

    #menu-toggle {
        display: none;
    }

    #nav-menu {
        display: flex;
        flex-direction: row;
        justify-content: space-around;
        position: static;
        opacity: 1;
    }

    nav ul li {
        display: inline-block;
        border-bottom: none;
    }

    li.link_one{
        margin-top: 30px;
        margin-bottom: 30px;
    }

}