:root {
  --color-bg: #fafafa;
  --color-surface: #ffffff;
  --color-text: #1a1a1a;
  --color-text-sub: #6b7280;
  --color-border: #e5e7eb;
  --color-accent: #1a1a1a;
  --color-accent-soft: #f3f4f6;
  --radius: 12px;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.06);
  --container: 1080px;
  --font-jp: "Noto Sans JP", system-ui, sans-serif;
  --font-en: "Inter", system-ui, sans-serif;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: var(--font-jp);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }

.container {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}

/* Header */
.site-header {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(8px);
  background: rgba(255,255,255,0.85);
}
.site-header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 64px;
}
.logo {
  font-family: var(--font-en);
  font-weight: 700;
  font-size: 22px;
  letter-spacing: -0.02em;
}
.logo-dot { color: var(--color-text-sub); }
.nav { display: flex; gap: 28px; align-items: center; font-size: 14px; }
.nav a { color: var(--color-text-sub); transition: color 0.15s; }
.nav a:hover { color: var(--color-text); }
.nav-cta {
  background: var(--color-accent);
  color: #fff !important;
  padding: 8px 16px;
  border-radius: 999px;
  font-weight: 500;
}
.nav-cta:hover { opacity: 0.85; color: #fff !important; }

/* Hero */
.hero {
  padding: 100px 0 80px;
  text-align: center;
}
.hero-eyebrow {
  font-family: var(--font-en);
  font-size: 13px;
  font-weight: 500;
  color: var(--color-text-sub);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin: 0 0 20px;
}
.hero-title {
  font-size: clamp(32px, 5vw, 52px);
  font-weight: 700;
  line-height: 1.3;
  margin: 0 0 24px;
  letter-spacing: -0.02em;
}
.hero-lead {
  font-size: 16px;
  color: var(--color-text-sub);
  margin: 0 auto 40px;
  max-width: 560px;
}
.hero-cta {
  display: flex;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
}
.btn {
  display: inline-block;
  padding: 14px 28px;
  border-radius: 999px;
  font-weight: 500;
  font-size: 15px;
  transition: all 0.15s;
  border: 1px solid transparent;
}
.btn-primary {
  background: var(--color-accent);
  color: #fff;
}
.btn-primary:hover { opacity: 0.85; }
.btn-ghost {
  background: transparent;
  color: var(--color-text);
  border-color: var(--color-border);
}
.btn-ghost:hover { background: var(--color-accent-soft); }

/* Section */
.section-title {
  font-size: 28px;
  font-weight: 700;
  margin: 0 0 40px;
  letter-spacing: -0.01em;
}

/* Articles */
.articles { padding: 60px 0; }
.article-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 24px;
}
.article-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 28px 24px;
  transition: all 0.15s;
}
.article-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}
.article-card.placeholder { opacity: 0.7; }
.article-tag {
  display: inline-block;
  font-size: 12px;
  font-weight: 500;
  background: var(--color-accent-soft);
  color: var(--color-text-sub);
  padding: 4px 10px;
  border-radius: 999px;
  margin-bottom: 14px;
}
.article-card h3 {
  font-size: 17px;
  font-weight: 700;
  line-height: 1.5;
  margin: 0 0 10px;
}
.article-excerpt {
  font-size: 14px;
  color: var(--color-text-sub);
  margin: 0 0 16px;
}
.article-meta {
  font-size: 12px;
  color: var(--color-text-sub);
}

/* About */
.about {
  padding: 60px 0 100px;
}
.about p {
  font-size: 15px;
  color: var(--color-text-sub);
  max-width: 680px;
  margin: 0 0 16px;
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding: 32px 0;
  text-align: center;
}
.site-footer p {
  font-size: 13px;
  color: var(--color-text-sub);
  margin: 0;
}

/* ===== Article page ===== */
.container-narrow {
  max-width: 760px;
  margin: 0 auto;
  padding: 0 24px;
}
.article-page { padding: 40px 0 80px; }

.breadcrumb {
  font-size: 13px;
  color: var(--color-text-sub);
  margin-bottom: 32px;
}
.breadcrumb a { color: var(--color-text-sub); }
.breadcrumb a:hover { color: var(--color-text); }

.article-header {
  margin-bottom: 48px;
  padding-bottom: 32px;
  border-bottom: 1px solid var(--color-border);
}
.article-header h1 {
  font-size: clamp(26px, 4vw, 38px);
  font-weight: 700;
  line-height: 1.4;
  letter-spacing: -0.01em;
  margin: 12px 0 16px;
}
.article-meta-row {
  display: flex;
  gap: 18px;
  font-size: 13px;
  color: var(--color-text-sub);
}

/* Article body typography */
.article-body {
  font-size: 16px;
  line-height: 1.9;
}
.article-body h2 {
  font-size: 24px;
  font-weight: 700;
  margin: 56px 0 18px;
  padding-top: 12px;
  border-top: 3px solid var(--color-text);
  padding-top: 16px;
}
.article-body h3 {
  font-size: 19px;
  font-weight: 700;
  margin: 36px 0 14px;
  padding-left: 12px;
  border-left: 4px solid var(--color-text);
}
.article-body p { margin: 0 0 22px; }
.article-body ul, .article-body ol { margin: 0 0 22px; padding-left: 1.6em; }
.article-body li { margin-bottom: 6px; }
.article-body a {
  color: #1d4ed8;
  text-decoration: underline;
  text-underline-offset: 3px;
}
.article-body a:hover { opacity: 0.7; }
.article-body blockquote {
  margin: 24px 0;
  padding: 18px 22px;
  background: var(--color-accent-soft);
  border-left: 4px solid var(--color-text);
  border-radius: 4px;
  color: var(--color-text);
}
.article-body blockquote p:last-child { margin-bottom: 0; }
.article-body code {
  background: var(--color-accent-soft);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.9em;
  font-family: "SFMono-Regular", Menlo, Consolas, monospace;
}
.article-body pre {
  background: #1a1a1a;
  color: #f5f5f5;
  padding: 20px 22px;
  border-radius: 8px;
  overflow-x: auto;
  margin: 24px 0;
  font-size: 13px;
  line-height: 1.6;
}
.article-body pre code {
  background: transparent;
  padding: 0;
  color: inherit;
}
.article-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 24px 0;
  font-size: 14px;
}
.article-body th, .article-body td {
  padding: 12px 14px;
  border: 1px solid var(--color-border);
  text-align: left;
}
.article-body th {
  background: var(--color-accent-soft);
  font-weight: 600;
}
.article-body img {
  border-radius: 8px;
  margin: 24px 0;
}
.article-body hr {
  border: none;
  border-top: 1px solid var(--color-border);
  margin: 40px 0;
}

/* ===== Callout boxes ===== */
.box {
  margin: 28px 0;
  padding: 22px 26px;
  border-radius: 10px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
}
.box-title {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  font-size: 15px;
  margin-bottom: 12px;
  letter-spacing: 0.02em;
}
.box-title::before {
  content: "";
  display: inline-block;
  width: 4px;
  height: 18px;
  border-radius: 2px;
  background: currentColor;
}
.box ul, .box ol { margin: 0; padding-left: 1.4em; }
.box li { margin-bottom: 6px; }
.box li:last-child { margin-bottom: 0; }
.box p { margin: 0 0 10px; }
.box p:last-child { margin-bottom: 0; }

/* Info box (青系：豆知識・補足) */
.box-info {
  background: #eff6ff;
  border-color: #bfdbfe;
  color: #1e3a8a;
}
.box-info .box-title { color: #1d4ed8; }

/* Point box (黒：要点・ポイント) */
.box-point {
  background: #f9fafb;
  border-color: #1a1a1a;
  border-left: 5px solid #1a1a1a;
}
.box-point .box-title { color: #1a1a1a; }

/* Tip box (緑：おすすめ・ヒント) */
.box-tip {
  background: #f0fdf4;
  border-color: #bbf7d0;
  color: #14532d;
}
.box-tip .box-title { color: #15803d; }

/* Warning box (黄：注意) */
.box-warn {
  background: #fefce8;
  border-color: #fde68a;
  color: #713f12;
}
.box-warn .box-title { color: #b45309; }

/* Check list (チェックボックス風箇条書き) */
.checklist { list-style: none; padding-left: 0; margin: 18px 0; }
.checklist li {
  position: relative;
  padding: 8px 0 8px 32px;
  border-bottom: 1px dashed var(--color-border);
}
.checklist li:last-child { border-bottom: none; }
.checklist li::before {
  content: "✓";
  position: absolute;
  left: 6px;
  top: 8px;
  width: 20px;
  height: 20px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--color-text);
  color: #fff;
  border-radius: 4px;
  font-size: 12px;
  font-weight: 700;
}

/* Strong/bold emphasis tweak */
.article-body strong {
  background: linear-gradient(transparent 65%, #fef08a 65%);
  font-weight: 700;
  padding: 0 2px;
}

/* Article images with caption support */
.article-body figure {
  margin: 32px 0;
  text-align: center;
}
.article-body figure img {
  display: block;
  margin: 0 auto;
  border-radius: 10px;
  box-shadow: var(--shadow-md);
}
.article-body figcaption {
  margin-top: 10px;
  font-size: 13px;
  color: var(--color-text-sub);
}

/* Related articles section */
.related-articles {
  margin-top: 80px;
  padding-top: 48px;
  border-top: 1px solid var(--color-border);
}
.related-articles h2 {
  font-size: 22px;
  margin: 0 0 28px;
}

/* CTA block */
.cta-block {
  margin-top: 60px;
  padding: 40px 32px;
  background: var(--color-accent-soft);
  border-radius: var(--radius);
  text-align: center;
}
.cta-block h2 {
  font-size: 22px;
  margin: 0 0 12px;
}
.cta-block p {
  color: var(--color-text-sub);
  margin: 0 0 24px;
  font-size: 15px;
}

/* Pillar grid (top page) */
.pillars { padding: 60px 0 20px; }
.pillar-card { border-color: var(--color-text); }

/* Empty state */
.empty-state {
  color: var(--color-text-sub);
  text-align: center;
  padding: 40px 0;
}

/* Author box (記事の著者ボックス) */
.author-box {
  display: flex;
  gap: 16px;
  align-items: flex-start;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 18px 20px;
  margin: 0 0 32px;
}
.author-box-top {
  margin-top: 8px;
  margin-bottom: 32px;
}
.author-box-bottom {
  margin-top: 48px;
  margin-bottom: 24px;
  background: var(--color-accent-soft);
}
.author-box-avatar {
  flex-shrink: 0;
  width: 52px;
  height: 52px;
  border-radius: 50%;
  background: var(--color-accent);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-en);
  font-weight: 700;
  font-size: 22px;
}
.author-box-text {
  flex: 1;
  min-width: 0;
}
.author-box-label {
  font-size: 12px;
  font-weight: 500;
  color: var(--color-text-sub);
  margin: 0 0 4px;
  letter-spacing: 0.05em;
}
.author-box-name {
  font-size: 15px;
  font-weight: 700;
  margin: 0 0 4px;
  line-height: 1.4;
}
.author-box-name a {
  color: var(--color-text);
  border-bottom: 1px solid transparent;
}
.author-box-name a:hover {
  border-bottom-color: var(--color-text);
}
.author-box-tagline {
  font-size: 12px;
  font-weight: 500;
  color: var(--color-text-sub);
  margin-left: 8px;
}
.author-box-bio {
  font-size: 13px;
  color: var(--color-text-sub);
  line-height: 1.65;
  margin: 0;
}
.author-box-link {
  display: inline-block;
  margin-top: 10px;
  font-size: 13px;
  font-weight: 500;
  color: var(--color-text);
  border-bottom: 1px solid var(--color-text);
  padding-bottom: 1px;
}
.author-box-link:hover {
  opacity: 0.7;
}

/* Profile page (about/author-yoshi) */
.profile-hero {
  display: flex;
  align-items: center;
  gap: 24px;
  padding: 32px 0 24px;
  margin-bottom: 8px;
  border-bottom: 1px solid var(--color-border);
}
.profile-handle {
  font-family: var(--font-en);
  font-size: 14px;
  font-weight: 600;
  color: var(--color-text-sub);
  letter-spacing: 0.1em;
  margin: 0 0 8px;
}
.profile-tagline {
  font-size: 26px;
  font-weight: 700;
  line-height: 1.4;
  margin: 0 0 8px;
}
.profile-hero-text p:last-child {
  font-size: 14px;
  color: var(--color-text-sub);
  margin: 0;
}
.profile-footer-note {
  font-size: 12px;
  color: var(--color-text-sub);
  text-align: center;
  margin-top: 32px;
  padding-top: 16px;
  border-top: 1px dashed var(--color-border);
}

@media (max-width: 640px) {
  .hero { padding: 60px 0 50px; }
  .nav { gap: 16px; }
  .nav a:not(.nav-cta) { display: none; }
  .article-body h2 { font-size: 21px; margin-top: 44px; }
  .article-body h3 { font-size: 17px; }
  .cta-block { padding: 32px 20px; }
  .author-box { padding: 14px 16px; gap: 12px; }
  .author-box-avatar { width: 44px; height: 44px; font-size: 18px; }
  .author-box-tagline { display: block; margin-left: 0; margin-top: 2px; }
  .profile-tagline { font-size: 22px; }
}