.column_header {
    background: url('../../images/archive-cover.jpg') no-repeat center center;
    background-size: cover;
    color: #fff;
    text-align: left;
    padding: 70px 0;
    height: 200px;
    display: flex;
    align-items: center;
    position: relative;
    margin-top: 70px; /* ヘッダーの高さ分を追加 */
}
.column_header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(
        to right,
        rgba(26, 0, 176, 0.9) 0%,
        rgba(0, 82, 176, 0.7) 50%,
        rgba(0, 153, 176, 0.5) 100%
    );
    z-index: 1;
}

.column_header .container {
    position: relative;
    z-index: 2;
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.column_header .title {
    font-size: 36px;
    line-height: 1.2;
    margin-bottom: 15px;
    font-weight: bold;
    letter-spacing: 0.05em;
    text-align: left;
    padding-left: 80px;
    display: block;
}
.column_header p {
    font-size: 16px;
    line-height: 1.6;
    margin: 0;
    opacity: 0.9;
    text-align: left;
    padding-left: 80px;
    display: block;
}

/* パンくずリスト */
.breadcrumbs {
    background-color: #ffffff;
    font-size: 0.8rem;
    padding: 15px 0;
    margin-bottom: 30px;
}

.breadcrumbs .container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.breadcrumbs a {
    color: #333;
    text-decoration: none;
    transition: color 0.3s ease;
}

.breadcrumbs a:hover {
    color: #0099B0;
}

.breadcrumbs-item,
.breadcrumbs-separator {
    display: inline;
    padding: 0 5px;
}

.breadcrumbs-separator {
    color: #666;
}


.single-column-container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 20px;
}

/* ヘッダー部分のスタイリング */
.single-column-header {
    margin-bottom: 30px;
}

/* 日付のスタイリング */
.single-column-date {
    color: #888;
    font-size: 0.9rem;
    margin-bottom: 10px;
    display: flex;
    gap: 10px;
}

/* タイトルのスタイリング */
.single-column-title {
    font-size: 1.8rem;
    margin-bottom: 20px;
    color: #333;
    line-height: 1.4;
}

/* サムネイル画像のスタイリング */
.single-column-thumbnail {
    margin-bottom: 40px;
    width: 100%;
}

.single-column-thumbnail img {
    width: 100%;
    max-width: 100%;
    height: auto;
    display: block;
    margin: 0 auto;
}

/* コンテンツのスタイリング */
.single-column-content {
    font-size: 1rem;
    color: #333;
    line-height: 1.6;
}

/* コンテンツ内の画像スタイリング */
.single-column-content img {
    max-width: 100%;
    width: 100%;
    height: auto;
    display: block;
    margin: 40px auto;
}

.single-column-content h1 {
    font-size: 2.2rem;
    font-weight: bold;
    margin-top: 32px;
    margin-bottom: 15px;
    position: relative;
}

.single-column-content h1::after {
    position: absolute;
    content: " ";
    display: block;
    border-bottom: solid 1px #333;
    bottom: -10px;
    width: 13%;
}

/* 各見出しタグのスタイリング */
.single-column-content h2 {
    font-size: 1.8rem;
    color: #0099B0;
    border-bottom: 2px solid #0099B0;
    padding-bottom: 5px;
    line-height: 1.5em;
    margin-top: 32px;
    font-weight: bold;
}

.single-column-content h3 {
    font-size: 1.2rem;
    line-height: 1.5em;
    margin-top: 32px;
    color: #0099B0;
    position: relative;
    padding-left: 50px;
    font-weight: bold;
}

.single-column-content h3::after {
    content: '';
    position: absolute;
    top: 50%;
    -webkit-transform: translateY(-50%);
    transform: translateY(-50%);
    width: 45px;
    height: 2px;
    background-color: #0099B0;
    left: 0;
}

.single-column-content h4 {
    font-size: 1.3rem;
    font-weight: bold;
    color: #333;
    margin: 30px 0 20px;
    padding-left: 18px;
    position: relative;
    line-height: 1.4;
}

.single-column-content h4::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0.5em;
    width: 8px;
    height: 8px;
    background: #0099B0;
    transform: translateY(-50%);
}

/* 段落のスタイリング */
.single-column-content p {
    font-size: 1rem;
    line-height: 1.8571428em;
    margin-top: 50px;
    text-align: justify;
    text-justify: inter-ideograph;
}

.single-column-content br {
    display: none;
}

/* フッター部分のスタイリング */
.single-column-footer {
    margin-top: 20px;
    margin-bottom: 20px;
    text-align: center;
}

.back-to-columns {
    display: inline-block;
    padding: 15px 40px;
    background: #0099B0;
    color: #fff;
    text-decoration: none;
    transition: background-color 0.3s ease;
}

.back-to-columns:hover {
    background: #007a8c;
}

/* レスポンシブ対応 */
@media (max-width: 768px) {
    .column_header {
        padding: 50px 0;
    }

    .column_header .title {
        font-size: 28px;
        padding-left: 20px;
    }

    .column_header p {
        font-size: 14px;
        padding-left: 20px;
    }


    .single-column-container {
        padding: 0 15px;
    }

    .single-column-title {
        font-size: 1.5rem;
    }

    .single-column-content h2 {
        font-size: 1.5rem;
        padding: 15px 20px;
        margin: 40px 0 25px;
    }

    .single-column-content h3 {
        font-size: 1.3rem;
        margin: 35px 0 20px;
    }

    .single-column-content h4 {
        font-size: 1.2rem;
        margin: 25px 0 15px;
    }

    .single-column-thumbnail {
        margin-bottom: 30px;
    }

    .single-column-content img {
        margin: 30px auto;
    }
}

@media (max-width: 480px) {
    .column_header {
        margin-top: 60px; /* ヘッダーの高さ分を追加 */
    }
    
    .column_header .title {
        font-size: 24px;
        padding-left: 15px;
    }

    .column_header p {
        padding-left: 15px;
    }

    .single-column-title {
        font-size: 1.3rem;
    }

    .back-to-columns {
        padding: 12px 30px;
        font-size: 0.9rem;
    }

    .single-column-content h2 {
        font-size: 1.3rem;
        padding: 12px 15px;
        margin: 30px 0 20px;
    }

    .single-column-content h3 {
        font-size: 1.2rem;
        margin: 25px 0 15px;
    }

    .single-column-content h4 {
        font-size: 1.1rem;
        margin: 20px 0 12px;
    }
}