/* ==========================================================================
   コラム機能（一覧・記事詳細）専用スタイル
   style.css の CSS変数・デザイントーンを踏襲
   ========================================================================== */

.primary-nav a.active { color: var(--brand); }

/* --- コラム一覧：ヒーロー --- */
.column-hero-section {
  position: relative;
  overflow: hidden;
  padding-block: 64px 56px;
  color: #fff;
  background:
    radial-gradient(900px 460px at 82% 0%, rgba(79,70,229,.4), transparent 60%),
    radial-gradient(700px 420px at 10% 20%, rgba(34,211,238,.2), transparent 62%),
    linear-gradient(135deg, #08111f 0%, #111827 55%, #171449 100%);
}
.column-hero-section .eyebrow { color: #dbeafe; }
.column-hero-section h1 {
  margin: 0 0 16px;
  max-width: 820px;
  font-size: clamp(28px, 4vw, 44px);
  line-height: 1.3;
  letter-spacing: -0.03em;
  font-weight: 900;
}
.column-hero-lead { max-width: 700px; margin: 0; color: #cbd5e1; font-size: 16px; line-height: 1.8; }

/* --- コラム一覧：カードグリッド --- */
.column-list-section { background: var(--surface-soft); }
.column-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); gap: 26px; }
.column-card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: 0 16px 42px rgba(15,23,42,.07);
  transition: transform .18s ease, box-shadow .18s ease;
}
.column-card:hover { transform: translateY(-4px); box-shadow: 0 22px 54px rgba(79,70,229,.16); }
.column-card-link { display: block; color: inherit; }
.column-card-thumb { margin: 0; aspect-ratio: 3 / 2; overflow: hidden; background: #0f172a; }
.column-card-thumb img { width: 100%; height: 100%; object-fit: cover; }
.column-card-body { padding: 22px 24px 26px; }
.column-card-tags { display: flex; flex-wrap: wrap; gap: 8px; margin: 0 0 12px; padding: 0; list-style: none; }
.column-card-tags span {
  display: inline-flex;
  padding: 5px 12px;
  border-radius: 999px;
  background: #eef2ff;
  color: var(--brand-dark);
  font-size: 12px;
  font-weight: 800;
}
.column-card-date {
  display: block;
  margin: 0 0 10px;
  color: var(--muted);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .02em;
}
.column-card h2 { margin: 0 0 12px; font-size: 19px; line-height: 1.5; letter-spacing: -0.02em; }
.column-card-excerpt { margin: 0 0 16px; color: var(--muted); font-size: 14px; line-height: 1.75; }
.column-card-readmore { display: inline-flex; align-items: center; gap: 6px; color: var(--brand); font-weight: 800; font-size: 13px; }
.column-card-readmore i { font-size: 11px; transition: transform .18s ease; }
.column-card:hover .column-card-readmore i { transform: translateX(4px); }
.column-list-note { margin: 34px 0 0; text-align: center; color: var(--muted); font-size: 13px; }
.column-list-note i { color: var(--brand); margin-right: 4px; }

/* --- コラム記事詳細 --- */
.column-article { padding-block: 48px 20px; }
.column-breadcrumb { display: flex; align-items: center; gap: 8px; margin-bottom: 26px; color: var(--muted); font-size: 13px; }
.column-breadcrumb a { color: var(--muted); font-weight: 700; }
.column-breadcrumb a:hover { color: var(--brand); }
.column-breadcrumb i { font-size: 10px; color: #cbd5e1; }
.column-breadcrumb span { color: var(--text); font-weight: 800; }

.column-article-header { margin-bottom: 28px; }
.column-article-header h1 {
  margin: 0 0 10px;
  font-size: clamp(26px, 3.6vw, 38px);
  line-height: 1.35;
  letter-spacing: -0.03em;
  font-weight: 900;
  color: var(--text);
}
.column-article-subtitle { margin: 0 0 14px; color: var(--muted); font-size: 17px; line-height: 1.7; }
.column-article-date { display: block; color: var(--muted); font-size: 13px; font-weight: 700; }

.column-lead-image {
  margin: 0 0 34px;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: 0 18px 46px rgba(15,23,42,.12);
}
.column-lead-image img { width: 100%; height: auto; display: block; }

.column-body { font-size: 16px; line-height: 2; color: #1f2937; }
.column-body p { margin: 0 0 26px; }

.column-diagram {
  margin: 8px 0 34px;
  padding: 14px;
  border-radius: var(--radius-xl);
  background: linear-gradient(135deg, #0f172a, #1e1b4b);
  box-shadow: 0 22px 60px rgba(15,23,42,.16);
}
.column-diagram img { width: 100%; height: auto; border-radius: 16px; border: 1px solid rgba(255,255,255,.12); }
.column-diagram figcaption { margin: 12px 6px 4px; color: #dbeafe; text-align: center; font-size: 13px; line-height: 1.7; }

.column-stat-strip {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
  margin: 0 0 34px;
  padding: 24px;
  border-radius: var(--radius-lg);
  background: #eef2ff;
  border: 1px solid var(--brand-light);
}
.column-stat-strip div { text-align: center; }
.column-stat-strip span { display: block; margin-bottom: 6px; color: var(--brand-dark); font-size: 12px; font-weight: 800; }
.column-stat-strip strong { display: block; color: var(--text); font: 900 18px/1.3 "Inter", sans-serif; letter-spacing: -.02em; }

.column-cta-box {
  margin: 40px 0;
  padding: clamp(26px, 4vw, 40px);
  border-radius: var(--radius-xl);
  background: linear-gradient(135deg, #111827, #312e81);
  color: #fff;
  text-align: center;
  box-shadow: var(--shadow);
}
.column-cta-box h2 { margin: 0 0 12px; font-size: clamp(20px, 2.6vw, 28px); line-height: 1.4; letter-spacing: -.02em; }
.column-cta-box p { margin: 0 0 22px; color: #cbd5e1; font-size: 14px; }
.column-cta-box .button { display: inline-flex; }

.column-back-link { margin: 30px 0 60px; }
.column-back-link a { display: inline-flex; align-items: center; gap: 8px; color: var(--brand); font-weight: 800; font-size: 14px; }
.column-back-link a:hover { text-decoration: underline; }

@media (max-width: 820px) {
  .column-grid { grid-template-columns: 1fr; }
  .column-stat-strip { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 560px) {
  .column-hero-section { padding-block: 48px 40px; }
  .column-body { font-size: 15px; }
  .column-stat-strip { grid-template-columns: 1fr; }
}