/* 全体を縦レイアウトに */
body {
    display: flex;
    flex-direction: column;
}

/* ヘッダー */
header {
    background: var(--color-primary);
    color: var(--color-text-pale);
    height: 80px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 40px;
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    font-family: "Kaisei Tokumin", serif;
}

header a {
    color: inherit;
    text-decoration: none;
}

#menu-button {
    display: none;
    background: transparent;
    padding: 4px 10px;
    border: 2px solid var(--color-text-pale);
    color: var(--color-text-pale);
    font-size: 18px;
    cursor: pointer;
}

/* メイン部分 */
.container {
    display: flex;
    flex: 1;
    margin-top: 80px; /* ヘッダー分 */
    background: var(--color-bg)
}

/* フッター */
footer {
    height: 60px;
    min-height: 60px; /* index.htmlでフッターが低くなってしまうため追加 */
    background: var(--color-footer);
    color: var(--color-text-pale);
    display: flex;
    align-items: center;
    justify-content: center;
}

/* ================= サイドバー ================= */
.sidebar {
    width: 240px;
    flex-shrink: 0; /* 画面幅に依存しない（狭くならない） */
    background: var(--color-bg);
    box-shadow: 2px 0 12px rgba(0,0,0,0.2);
    padding: 20px;
}

.sidebar a {
    display: block;
    padding: 10px;
    color: var(--color-text-dark);
    text-decoration: none;
    border-radius: 8px;
}

.sidebar a:hover {
    background: var(--color-hover);
}

/* ================= コンテンツ ================= */
.content {
    flex: 1;
    /* display: flex; */
    gap: 24px;
    padding: 20px;
}

/* ################# 2カラム用 ################# */
.content-2col {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: flex-start;
    gap: 24px;
    padding: 20px;
}

/* 左側エリア */
.main-left {
    flex: 0 1 500px;
    min-width: 0;
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 10px;
    align-items: stretch;
}

.board-top-area {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 8px 10px;
    border-radius: 8px;
}

.board-area {
    display: flex;
    flex-direction: column;
    align-items: stretch;
    gap: 10px;
}

.board-bottom-area {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 8px 10px;
    border-radius: 8px;
}

/* 右側エリア */
.main-right {
    flex: 0 1 500px;
    min-width: 0;
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 10px;
    align-items: stretch;
}

/* ################# 一般ページ用素材 ################# */
/* ================= ページ説明 ================= */
.page-header {
    text-align: center;
}

.page-title {
    margin-bottom: 24px;
    font-size: 48px;
    font-weight: 700;
    letter-spacing: 0.04em;
}

.page-description {
    /* max-width: 720px; */
    line-height: 2;
}

/* ================= コンテンツ ================= */
/* セクションタイトル */
.category-title {
    width: 100%;
    display: inline-block;
    margin-bottom: 40px;
    padding-bottom: 10px;
    border-bottom: 3px solid var(--color-primary);
    font-size: 1.8rem;
    font-weight: 700;
    letter-spacing: 0.08em;
}

.paragraph-title {
    width: 100%;
    display: inline-block;
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: 0.08em;
}

/* セクション内画像 */
.content-inside {
    width: 100%;
    max-width: 500px;
    height: auto;
}

.content-inside img {
    display: block;
    width: 100%;
    height: auto;
}

.content-inside figcaption {
    margin-bottom: 1rem;
    text-align: center;
}

/* ================= レスポンシブ ================= */
@media (max-width: 960px) {
    #menu-button {
        display: block;
    }

    .sidebar {
        position: fixed;
        top: 80px;
        left: -240px; /* openされなければ画面外 */
        width: 220px;
        height: calc(100vh - 80px);

        z-index: 1500;
        transition: left 0.3s ease;
    }
    .sidebar.open {
        left: 0;
    }

    .content-2col {
        flex-direction: column;
        align-items: center;
    }

    .main-left,
    .main-right {
        flex: none;
        width: 100%;
        max-width: 500px;
    }
}