<style>
        /* ==================================================
           ベース設定（ペパつくの雰囲気に合わせる）
           ================================================== */
        :root {
            --primary-color: #ff9800; /* ペパつくのオレンジ */
            --bg-color: #fcfcfc;
            --text-color: #333333;
            --box-bg: #ffffff;
        }

        body {
            font-family: 'Helvetica Neue', Arial, 'Hiragino Kaku Gothic ProN', 'Hiragino Sans', Meiryo, sans-serif;
            background-color: var(--bg-color);
            color: var(--text-color);
            line-height: 1.8;
            margin: 0;
            padding: 0;
            /* 背景にうっすらドット柄を入れて工作っぽさを出す */
            background-image: radial-gradient(#e0e0e0 1px, transparent 1px);
            background-size: 20px 20px;
        }

        /* ==================================================
           レイアウト枠
           ================================================== */
        .container {
            max-width: 800px;
            margin: 0 auto;
            padding: 20px;
        }

        .header-nav {
            margin-bottom: 30px;
            text-align: center;
        }

        .header-nav a {
            display: inline-block;
            background-color: var(--box-bg);
            color: var(--primary-color);
            text-decoration: none;
            padding: 10px 20px;
            border-radius: 30px;
            font-weight: bold;
            box-shadow: 0 4px 6px rgba(0,0,0,0.05);
            border: 2px solid var(--primary-color);
            transition: all 0.2s;
        }

        .header-nav a:hover {
            transform: translateY(-2px);
            box-shadow: 0 6px 12px rgba(0,0,0,0.1);
        }

        /* ==================================================
           記事エリアのデザイン
           ================================================== */
        .article-card {
            background-color: var(--box-bg);
            border-radius: 20px;
            padding: 30px;
            box-shadow: 0 8px 24px rgba(0,0,0,0.08);
            margin-bottom: 40px;
        }

        /* 記事ヘッダー */
        .article-header {
            border-bottom: 2px dashed #eeeeee;
            padding-bottom: 20px;
            margin-bottom: 30px;
        }

        .article-date {
            color: #888888;
            font-size: 0.9em;
            margin-bottom: 10px;
            display: block;
        }

        .article-title {
            font-size: 1.8em;
            color: #222222;
            margin: 0 0 15px 0;
            line-height: 1.4;
        }

        .article-tags span {
            display: inline-block;
            background-color: #fff3e0;
            color: #ef6c00;
            padding: 4px 12px;
            border-radius: 15px;
            font-size: 0.85em;
            margin-right: 8px;
            font-weight: bold;
        }

        /* ==================================================
           記事本文（AIに出力させる部分）のスタイル
           ================================================== */
        .article-body h2 {
            font-size: 1.5em;
            color: var(--primary-color);
            border-bottom: 3px solid #ffcc80;
            padding-bottom: 8px;
            margin-top: 40px;
            margin-bottom: 20px;
        }

        .article-body h3 {
            font-size: 1.3em;
            color: #444;
            border-left: 5px solid var(--primary-color);
            padding-left: 12px;
            margin-top: 30px;
            margin-bottom: 15px;
        }

        .article-body p {
            margin-bottom: 20px;
            font-size: 1.05em;
        }

        .article-body img {
            max-width: 100%;
            height: auto;
            border-radius: 12px;
            box-shadow: 0 4px 12px rgba(0,0,0,0.1);
            margin: 20px 0;
            display: block;
        }

        .article-body ul {
            background-color: #fafafa;
            padding: 20px 20px 20px 40px;
            border-radius: 12px;
            margin-bottom: 25px;
        }

        .article-body li {
            margin-bottom: 10px;
        }

        /* ふきだし風の強調ブロック */
        .point-box {
            background-color: #e3f2fd;
            border: 2px solid #90caf9;
            border-radius: 15px;
            padding: 20px;
            margin: 30px 0;
            position: relative;
        }
        .point-box::before {
            content: "💡 POINT";
            position: absolute;
            top: -15px;
            left: 20px;
            background-color: #1976d2;
            color: white;
            padding: 4px 12px;
            border-radius: 20px;
            font-size: 0.85em;
            font-weight: bold;
        }

        /* ==================================================
           レスポンシブ対応（スマホ向け）
           ================================================== */
        @media (max-width: 600px) {
            .container {
                padding: 15px;
            }
            .article-card {
                padding: 20px;
                border-radius: 15px;
            }
            .article-title {
                font-size: 1.4em;
            }
            .article-body h2 {
                font-size: 1.3em;
            }
        }
    </style>