body {
    font-family: Arial, sans-serif;
    font-size: large;
    margin: 0;
    padding: 0;
    display: flex;
}
.sidebar {
    width: 200px;
    background-color: #f0f0f0;
    padding: 20px;
    height: 100vh;
}
.sidebar a {
    text-decoration: none;
    color: #4a4a4a;
}

.sidebar a:hover {
    text-decoration: underline;
}

/*sidebarのヘッダーの設定*/
.sidebar h3 {
    color: #4a4a4a;
    border-bottom: 1px solid #4a4a4a;
    padding-bottom: 10px;
    margin-bottom: 20px;
    text-align: center;
}

.main-content {
    flex-grow: 1;
    padding: 20px;
    position: relative;
}

/*main-content の ul のスタイルを設定*/
.main-content ul {
    list-style-type: none;
    padding-left: 0;
    margin: 0;
}

/*main-contentのヘッダー設定*/
h1 {
    color: #4a4a4a;
    border-bottom: 1px solid #4a4a4a;
    padding-bottom: 10px;
    text-align: center; /* タイトルを中央揃えにする */
    margin-top: 40px; /* 上部の余白を増やす */
    margin-bottom: 40px; /* 下部の余白を増やす */
}


.notice {
    background-color: #f0f0f0;
    padding: 15px;
    margin-top: 20px;
}
ul {
    list-style-type: none;
    padding-left: 0;
    margin: 0;
}
li {
    padding: 5px 0;
    cursor: pointer;
}
.submenu {
    display: none;
    padding-left: 15px;
}
.submenu li {
    padding: 3px 0;
}
.search-container {
    position: absolute;
    top: 20px;
    right: 20px;
    display: flex;
    align-items: center;
}
.search-icon {
    font-size: 20px;
    color: #4a4a4a;
    cursor: pointer;
    margin-left: 10px;
}
#search-input {
    display: none;
    padding: 5px;
    border: 1px solid #4a4a4a;
    border-radius: 3px;
}
.expandable::before {
    content: '▶ ';
}
.expandable.expanded::before {
    content: '▼ ';
}
.expandable.expanded + .submenu {
    display: block;
}