@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+JP:wght@400;500;700&family=Noto+Serif+JP:wght@400;700&display=swap');

:root {
  --bg: #fafaf8;
  --bg-card: #ffffff;
  --text: #1a1a1a;
  --text-muted: #6b7280;
  --accent: #2563eb;
  --accent-light: #eff6ff;
  --border: #e5e7eb;
  --tag-bg: #f3f4f6;
  --max-width: 760px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { font-size: 16px; scroll-behavior: smooth; scroll-padding-top: 80px; }

body {
  font-family: 'Noto Sans JP', sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.8;
}

/* Header */
header {
  background: #fff;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
}
.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.site-title {
  font-family: 'Noto Serif JP', serif;
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text);
  text-decoration: none;
  letter-spacing: 0.02em;
}
nav a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.875rem;
  margin-left: 1.5rem;
  transition: color 0.2s;
}
nav a:hover { color: var(--accent); }

/* Main */
main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 2.5rem 1.5rem;
}

/* Hero (index) */
.hero {
  margin-bottom: 3rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--border);
}
.hero h1 {
  font-family: 'Noto Serif JP', serif;
  font-size: 1.6rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  line-height: 1.5;
}
.hero p { color: var(--text-muted); font-size: 0.95rem; }

/* Post list */
.post-list { list-style: none; }
.post-item {
  padding: 1.75rem 0;
  border-bottom: 1px solid var(--border);
}
.post-item:last-child { border-bottom: none; }
.post-meta {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 0.5rem;
}
.post-date {
  font-size: 0.8rem;
  color: var(--text-muted);
}
.post-tag {
  font-size: 0.75rem;
  background: var(--tag-bg);
  color: var(--text-muted);
  padding: 0.15rem 0.6rem;
  border-radius: 100px;
}
.post-item h2 {
  font-family: 'Noto Serif JP', serif;
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  line-height: 1.6;
}
.post-item h2 a {
  color: var(--text);
  text-decoration: none;
  transition: color 0.2s;
}
.post-item h2 a:hover { color: var(--accent); }
.post-excerpt { font-size: 0.9rem; color: var(--text-muted); line-height: 1.7; }
.read-more {
  display: inline-block;
  margin-top: 0.75rem;
  font-size: 0.85rem;
  color: var(--accent);
  text-decoration: none;
  font-weight: 500;
}
.read-more:hover { text-decoration: underline; }

/* TOC */
.toc {
  background: var(--accent-light);
  border: 1px solid #dbeafe;
  border-radius: 10px;
  padding: 1.25rem 1.5rem;
  margin: 0 0 3.5rem;
}
.toc-title {
  font-family: 'Noto Serif JP', serif;
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 0.6rem;
  display: flex;
  align-items: center;
  gap: 0.4rem;
}
.toc-title::before {
  content: "";
  display: inline-block;
  width: 3px;
  height: 0.95rem;
  background: var(--accent);
  border-radius: 2px;
}
.toc-list {
  margin: 0;
  padding-left: 0;
  font-size: 0.875rem;
  list-style: none;
  counter-reset: toc-h2;
}
.toc-list li {
  margin: 0.25rem 0;
  line-height: 1.6;
  position: relative;
}
.toc-list .toc-item-h2 {
  counter-increment: toc-h2;
  padding-left: 1.75rem;
}
.toc-list .toc-item-h2::before {
  content: counter(toc-h2) ".";
  position: absolute;
  left: 0;
  color: var(--text-muted);
}
.toc-list .toc-item-h3 {
  padding-left: 2.75rem;
  font-size: 0.82rem;
  color: var(--text-muted);
}
.toc-list .toc-item-h3::before {
  content: "・";
  position: absolute;
  left: 1.5rem;
  color: var(--text-muted);
}
.toc-list a {
  color: var(--text);
  text-decoration: none;
  border-bottom: 1px dotted transparent;
  transition: border-color 0.2s, color 0.2s;
}
.toc-list a:hover {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

/* Reading time */
.reading-time {
  font-size: 0.78rem;
  color: var(--text-muted);
}

/* Anchor offset for sticky header (fallback for browsers without scroll-padding-top support) */
.article-body h2,
.article-body h3 {
  scroll-margin-top: 80px;
}

/* Breadcrumb */
.breadcrumb {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 1.25rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  align-items: center;
}
.breadcrumb a {
  color: var(--accent);
  text-decoration: none;
}
.breadcrumb a:hover { text-decoration: underline; }
.breadcrumb span { color: var(--text-muted); }

/* Ad slot */
.ad-wrap {
  margin-top: 2.5rem;
  padding: 0.85rem;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 12px;
}
.ad-label {
  margin: 0 0 0.4rem;
  color: var(--text-muted);
  font-size: 0.72rem;
  letter-spacing: 0.04em;
}

/* Article */
.article-header { margin-bottom: 2rem; padding-bottom: 1.5rem; border-bottom: 1px solid var(--border); }
.article-header h1 {
  font-family: 'Noto Serif JP', serif;
  font-size: 1.6rem;
  font-weight: 700;
  line-height: 1.6;
  margin-bottom: 1rem;
}
.article-meta { display: flex; align-items: center; gap: 0.75rem; flex-wrap: wrap; }
.article-body { font-size: 1rem; line-height: 2; }
.article-body h2 {
  font-family: 'Noto Serif JP', serif;
  font-size: 1.25rem;
  font-weight: 700;
  margin: 2.5rem 0 1rem;
  padding-left: 0.75rem;
  border-left: 3px solid var(--accent);
}
.article-body h3 {
  font-size: 1.05rem;
  font-weight: 700;
  margin: 2rem 0 0.75rem;
}
.article-body p { margin-bottom: 1.5rem; }
.article-body ul, .article-body ol {
  margin: 0 0 1.5rem 1.5rem;
}
.article-body li { margin-bottom: 0.4rem; }
.article-body a { color: var(--accent); }
.article-body blockquote {
  border-left: 3px solid var(--border);
  padding-left: 1rem;
  color: var(--text-muted);
  margin: 1.5rem 0;
}
.article-body code {
  background: var(--tag-bg);
  padding: 0.15em 0.4em;
  border-radius: 3px;
  font-size: 0.9em;
}
.article-body pre {
  background: #1e1e2e;
  color: #cdd6f4;
  padding: 1.25rem;
  border-radius: 8px;
  overflow-x: auto;
  margin: 1.5rem 0;
}
.article-body pre code { background: none; padding: 0; }
.article-body img {
  max-width: 100%;
  border-radius: 8px;
  margin: 1.5rem 0;
}

/* Profile */
.author-card {
  margin-top: 3rem;
  padding: 1.5rem;
  background: var(--accent-light);
  border-radius: 12px;
  display: flex;
  gap: 1rem;
  align-items: flex-start;
}
.author-card-info h3 { font-size: 0.95rem; font-weight: 700; margin-bottom: 0.25rem; }
.author-card-info p { font-size: 0.875rem; color: var(--text-muted); }

/* Pages */
.page-header { margin-bottom: 2rem; }
.page-header h1 {
  font-family: 'Noto Serif JP', serif;
  font-size: 1.5rem;
  font-weight: 700;
}
.page-body { font-size: 0.95rem; line-height: 2; }
.page-body h2 { font-size: 1.1rem; font-weight: 700; margin: 2rem 0 0.75rem; }
.page-body p { margin-bottom: 1.25rem; }

/* Contact form */
.contact-form { max-width: 520px; }
.form-group { margin-bottom: 1.25rem; }
.form-group label { display: block; font-size: 0.875rem; font-weight: 500; margin-bottom: 0.4rem; }
.form-group input, .form-group textarea {
  width: 100%;
  padding: 0.6rem 0.85rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 0.95rem;
  font-family: inherit;
  background: #fff;
  transition: border-color 0.2s;
}
.form-group input:focus, .form-group textarea:focus {
  outline: none;
  border-color: var(--accent);
}
.form-group textarea { min-height: 140px; resize: vertical; }
.btn {
  display: inline-block;
  background: var(--accent);
  color: #fff;
  padding: 0.6rem 1.5rem;
  border-radius: 6px;
  border: none;
  font-size: 0.95rem;
  font-family: inherit;
  cursor: pointer;
  text-decoration: none;
  transition: opacity 0.2s;
}
.btn:hover { opacity: 0.85; }

/* Footer */
footer {
  margin-top: 4rem;
  border-top: 1px solid var(--border);
  padding: 2rem 1.5rem;
  text-align: center;
  font-size: 0.8rem;
  color: var(--text-muted);
}
footer a { color: var(--text-muted); text-decoration: none; margin: 0 0.5rem; }
footer a:hover { color: var(--accent); }

/* Responsive */
@media (max-width: 600px) {
  .hero h1 { font-size: 1.3rem; }
  .article-header h1 { font-size: 1.3rem; }
}