/* CSS変数 */
:root {
  --color-text-primary: #1d1d1f;
  --color-text-secondary: #6e6e73;
  --color-text-tertiary: #86868b;
  --color-bg-primary: #fbfbfd;
  --color-bg-secondary: #f5f5f7;
  --color-bg-white: #ffffff;
  --color-border-subtle: #e8e8ed;
  --color-accent: #2d8653;
  --radius-md: 8px;
  --max-width-content: 980px;
  --max-width-narrow: 680px;
}

/* ========== Article Page ========== */

.article-header {
  padding: 140px 32px 48px;
  max-width: var(--max-width-narrow);
  margin: 0 auto;
}

.article-back {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  color: var(--color-text-tertiary);
  margin-bottom: 32px;
  transition: color 0.2s;
}

.article-back:hover {
  color: var(--color-text-primary);
}

.article-header .article-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
}

.article-header .article-category {
  font-size: 12px;
  font-weight: 600;
  color: var(--color-accent);
  letter-spacing: 0.04em;
}

.article-header .article-date {
  font-size: 12px;
  color: var(--color-text-tertiary);
}

.article-header h1 {
  font-size: clamp(24px, 4vw, 32px);
  font-weight: 700;
  line-height: 1.4;
  letter-spacing: -0.01em;
  margin-bottom: 20px;
  color: var(--color-text-primary);
}

.article-writer-info {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px 0;
  border-top: 1px solid var(--color-border-subtle);
}

.article-writer-avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--color-bg-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  font-weight: 600;
  color: var(--color-text-secondary);
}

.article-writer-name {
  font-size: 14px;
  font-weight: 600;
}

.article-writer-role {
  font-size: 12px;
  color: var(--color-text-tertiary);
}

/* 本文 */
.article-body {
  max-width: var(--max-width-narrow);
  margin: 0 auto;
  padding: 0 32px 80px;
}

.article-body p {
  font-size: 16px;
  line-height: 2;
  margin-bottom: 24px;
  color: var(--color-text-primary);
}

.article-body hr {
  border: none;
  border-top: 1px solid var(--color-border-subtle);
  margin: 40px 0;
}

.article-body strong {
  font-weight: 600;
  color: var(--color-text-primary);
}

.article-body .highlight {
  background: var(--color-bg-secondary);
  padding: 24px;
  border-radius: var(--radius-md);
  margin: 32px 0;
}

.article-body .highlight p {
  margin-bottom: 0;
  font-size: 17px;
  font-weight: 500;
}

/* 次の記事 */
.article-next {
  max-width: var(--max-width-narrow);
  margin: 0 auto;
  padding: 0 32px 80px;
}

.article-next h3 {
  font-size: 13px;
  font-weight: 600;
  color: var(--color-text-tertiary);
  letter-spacing: 0.04em;
  margin-bottom: 16px;
}

.article-next a {
  display: block;
  padding: 20px;
  border: 1px solid var(--color-border-subtle);
  border-radius: var(--radius-md);
  transition: all 0.2s;
}

.article-next a:hover {
  border-color: var(--color-text-primary);
  transform: translateY(-2px);
}

.article-next .next-title {
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 4px;
}

.article-next .next-writer {
  font-size: 12px;
  color: var(--color-text-tertiary);
}

/* レスポンシブ */
@media (max-width: 640px) {
  .article-header {
    padding: 120px 20px 40px;
  }

  .article-body {
    padding: 0 20px 60px;
  }

  .article-next {
    padding: 0 20px 60px;
  }
}