/* ─── ハブヒーロー ─── */
.hub-hero {
  position: relative;
  min-height: 40vh;
  min-height: 40svh;
  display: flex;
  align-items: flex-end;
  overflow: hidden;
}

.hub-hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.hub-hero-bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
  opacity: 0.45;
}

.hub-hero-bg::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(
    to bottom,
    rgba(10,10,15,0.6) 0%,
    rgba(10,10,15,0.85) 100%
  );
}

.hub-hero-content {
  position: relative;
  z-index: 1;
  padding: var(--space-2xl) 0;
  width: 100%;
}

/* ─── ステップリスト ─── */
.step-list {
  display: flex;
  flex-direction: column;
  gap: 0;
  counter-reset: step;
  position: relative;
}

.step-list::before {
  content: '';
  position: absolute;
  left: 19px;
  top: 24px;
  bottom: 24px;
  width: 1px;
  background: linear-gradient(to bottom, var(--accent-cyan), transparent);
  opacity: 0.3;
}

.step-item {
  display: grid;
  grid-template-columns: 40px 1fr;
  gap: var(--space-lg);
  padding: var(--space-lg) 0;
  border-bottom: 1px solid var(--border);
  position: relative;
}

.step-item:last-child { border-bottom: none; }

.step-num {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: rgba(0,240,255,0.08);
  border: 1px solid rgba(0,240,255,0.25);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 13px;
  font-weight: 700;
  color: var(--accent-cyan);
  flex-shrink: 0;
  position: relative;
  z-index: 1;
}

.step-body h3 {
  font-size: 17px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--space-xs);
}

.step-body p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.65;
}

.step-body .step-link {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 13px;
  color: var(--accent-cyan);
  margin-top: var(--space-sm);
  transition: gap var(--transition);
}

.step-body .step-link:hover { gap: 8px; }

/* ─── ハブレイアウト ─── */
.hub-layout {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: var(--space-2xl);
  align-items: start;
}

.hub-sidebar {
  position: sticky;
  top: calc(var(--header-h) + var(--space-lg));
}

.sidebar-box {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: var(--space-lg);
  margin-bottom: var(--space-lg);
}

.sidebar-box h3 {
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: var(--space-md);
}

.sidebar-nav-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

.sidebar-nav-list a {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: 14px;
  color: var(--text-secondary);
  padding: 6px 8px;
  border-radius: 4px;
  transition: background var(--transition), color var(--transition);
}

.sidebar-nav-list a:hover,
.sidebar-nav-list a.active {
  background: rgba(0,240,255,0.06);
  color: var(--accent-cyan);
}

/* ─── 記事グリッド ─── */
.hub-articles-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-lg);
}

/* ─── 関連カード ─── */
.related-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-lg);
}

/* ─── レスポンシブ ─── */
@media (max-width: 1024px) {
  .hub-layout {
    grid-template-columns: 1fr;
  }
  .hub-sidebar {
    position: static;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-lg);
  }
}

@media (max-width: 768px) {
  .hub-sidebar { grid-template-columns: 1fr; }
  .related-grid { grid-template-columns: 1fr; }
}