/* --- 1. 基本設定と変数 --- */
:root {
  --zeb-blue: #005bac;    /* 信頼のブルー */
  --zeb-green: #238f77;   /* 清潔感のある緑 */
  --bg-gradient: linear-gradient(135deg, #f0f7f9 0%, #e8f3f0 100%);
  --text-dark: #2c3e50;
  --text-muted: #666;
  --white: #ffffff;
}

body {
  margin: 0;
  background-color: #fcfcfc;
  font-family: "Helvetica Neue", Arial, "Hiragino Kaku Gothic ProN", "Hiragino Sans", Meiryo, sans-serif;
  color: var(--text-dark);
}

/* --- 2. ヘッダー上部（ロゴ・戻る） --- */
.article-header {
  background: var(--white);
  border-bottom: 1px solid #eee;
}

.header-top {
  max-width: 1000px;
  margin: 0 auto;
  padding: 15px 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.site-logo {
  display: flex;
  align-items: center;
  text-decoration: none;
  font-weight: bold;
  color: var(--zeb-blue);
  font-size: 1.25rem;
}

.site-logo img {
  height: 32px;
  margin-right: 10px;
}

.column-back {
  text-decoration: none;
  color: var(--zeb-green);
  background: #eef9f6;
  padding: 6px 16px;
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 600;
  transition: all 0.3s ease;
}

.column-back:hover {
  background: var(--zeb-green);
  color: var(--white);
}

/* --- 3. 記事タイトルエリア（ヒーローセクション） --- */
.column-detail-header {
  background: var(--bg-gradient);
  padding: 60px 20px;
  text-align: center;
}

.column-detail-meta {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 12px;
  margin-bottom: 20px;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.column-detail-meta::before {
  content: attr(data-text); /* HTMLのdata-text属性を取得 */
  
  /* 以下、見た目の調整（例） */
  display: inline-block;
  padding: 2px 8px;
  margin-right: 10px;
  background-color: #0000ff; /* 赤色ラベル */
  color: #fff;  
  font-size: 0.8rem;
  font-weight: bold;
  border-radius: 3px;
}

.column-detail-title {
  max-width: 900px;
  margin: 0 auto 30px;
  font-size: 2.2rem;
  line-height: 1.4;
  color: var(--text-dark);
  font-weight: 700;
}

/* --- 4. 前後の記事ボタン --- */
.nav-article-buttons {
  display: flex;
  justify-content: center;
  gap: 15px;
}

.nav-prev-btn, .nav-next-btn {
  padding: 8px 20px;
  border: 1px solid var(--zeb-blue);
  border-radius: 4px;
  text-decoration: none;
  color: var(--zeb-blue);
  font-size: 0.85rem;
  background: rgba(255, 255, 255, 0.6);
  transition: all 0.3s;
}

.nav-prev-btn:hover, .nav-next-btn:hover {
  background: var(--zeb-blue);
  color: #fff;
}

/* --- 5. メインコンテンツ --- */
.column-detail-main {
  max-width: 800px;
  margin: -40px auto 60px; /* タイトルエリアに少し被せる */
  padding: 40px;
  background: var(--white);
  border-radius: 12px;
  box-shadow: 0 10px 30px rgba(0,0,0,0.08);
  position: relative;
  z-index: 10;
}

.column-detail-img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border-radius: 8px;
  margin-bottom: 30px;
}

.column-detail-main h2 {
  font-size: 1.5rem;
  color: var(--zeb-blue);
  border-left: 5px solid var(--zeb-green);
  padding-left: 15px;
  margin: 40px 0 20px;
}

.column-detail-main p {
  line-height: 1.8;
  margin-bottom: 1.5em;
  font-size: 1.05rem;
}

.back-btn {
  display: block;
  width: fit-content;
  margin: 40px auto 0;
  background: var(--white);
  color: var(--zeb-blue);
  border: 1px solid var(--zeb-blue);
  border-radius: 30px;
  padding: 10px 30px;
  font-weight: bold;
  cursor: pointer;
  transition: all 0.3s;
}

.back-btn:hover {
  background: var(--zeb-blue);
  color: #fff;
}

/* --- 6. レスポンシブ --- */
@media (max-width: 768px) {
  .column-detail-header { padding: 40px 15px; }
  .column-detail-title { font-size: 1.5rem; }
  .column-detail-main { margin-top: -20px; padding: 20px; width: 90%; }
  .header-top { padding: 10px 15px; }
  .site-logo span { font-size: 1rem; }
}