/* === ベースリセット & テーマ変数 === */
*, *::before, *::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

:root {
  --bg-color: #f5f7fb;
  --card-bg-color: rgba(255, 255, 255, 0.92);
  --text-color: #1f2933;
  --heading-color: #0f172a;
  --accent-grad: linear-gradient(90deg, #2563eb, #7c3aed);
  --accent-color-start: #2563eb;
  --border-color: rgba(15, 23, 42, 0.12);
  --quote-color: #4b5563;
  --code-bg-color: rgba(15, 23, 42, 0.08);
  --shadow-color: rgba(15, 23, 42, 0.15);
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Hiragino Sans", "Noto Sans CJK JP", "Helvetica Neue", Arial, sans-serif;
  margin: 0;
  color: var(--text-color);
  background-color: var(--bg-color);
  line-height: 1.7;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  font-size: 16px;
  overflow-x: hidden;
  position: relative;
  transition: background-color 0.3s ease, color 0.3s ease;
}

body.light-mode {
  --bg-color: #f5f7fb;
  --card-bg-color: rgba(255, 255, 255, 0.92);
  --text-color: #1f2933;
  --heading-color: #0f172a;
  --accent-grad: linear-gradient(90deg, #2563eb, #7c3aed);
  --accent-color-start: #2563eb;
  --border-color: rgba(15, 23, 42, 0.12);
  --quote-color: #4b5563;
  --code-bg-color: rgba(15, 23, 42, 0.08);
  --shadow-color: rgba(15, 23, 42, 0.15);
}

body.dark-mode {
  --bg-color: #0d1117;
  --card-bg-color: rgba(30, 36, 46, 0.78);
  --text-color: #c9d1d9;
  --heading-color: #f0f6fc;
  --accent-grad: linear-gradient(90deg, #3081f7, #9b59b6);
  --accent-color-start: #3081f7;
  --border-color: rgba(139, 148, 158, 0.3);
  --quote-color: #8b949e;
  --code-bg-color: rgba(13, 17, 23, 0.8);
  --shadow-color: rgba(0, 0, 0, 0.4);
}

/* オーロラ背景エフェクト */
body::before {
  content: '';
  position: fixed;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle at 20% 20%, rgba(37, 99, 235, 0.12), transparent 30%),
              radial-gradient(circle at 80% 70%, rgba(124, 58, 237, 0.1), transparent 35%);
  animation: aurora 20s linear infinite;
  z-index: -1;
  pointer-events: none;
}

body.dark-mode::before {
  background: radial-gradient(circle at 20% 20%, rgba(53, 129, 247, 0.18), transparent 32%),
              radial-gradient(circle at 80% 70%, rgba(155, 89, 182, 0.18), transparent 35%);
}

h1, h2, h3, h4, h5, h6 {
  color: var(--heading-color);
  line-height: 1.3;
}

a,
button {
  transition: color 0.2s ease-in-out, background-color 0.2s ease-in-out, border-color 0.2s ease-in-out;
}

a {
  color: var(--accent-color-start);
  text-decoration: none;
  transition: color 0.2s ease-in-out;
}

a:hover {
  text-decoration: underline;
  filter: brightness(1.2);
}

/* === レイアウト === */
.container {
  width: min(100%, 960px);
  margin: 0 auto;
  padding: clamp(1rem, 2vw, 1.5rem) clamp(1rem, 4vw, 2rem);
}

/* --- Sticky Footerのための設定 --- */
main {
  flex-grow: 1;
}

img,
svg,
video,
iframe {
  max-width: 100%;
  height: auto;
}

figure {
  margin: 0;
}

pre {
  padding: 1rem 1.25rem;
  background-color: var(--code-bg-color);
  border-radius: 12px;
  overflow-x: auto;
  border: 1px solid var(--border-color);
  position: relative;
}

code {
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin: 2rem 0;
  overflow: hidden;
  border-radius: 12px;
}

table th,
table td {
  padding: 0.75rem 1rem;
  border: 1px solid var(--border-color);
}

table th {
  text-align: left;
  background-color: var(--card-bg-color);
}

.copy-code-btn {
  position: absolute;
  top: 0.55rem;
  right: 0.55rem;
  padding: 0.35rem 0.6rem;
  background: rgba(15, 23, 42, 0.08);
  border: 1px solid rgba(15, 23, 42, 0.16);
  border-radius: 10px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: var(--heading-color);
  transition: background-color 0.2s ease, border-color 0.2s ease, color 0.2s ease, transform 0.2s ease;
}

body.dark-mode .copy-code-btn {
  background: rgba(255, 255, 255, 0.08);
  border-color: rgba(255, 255, 255, 0.16);
}

.copy-code-btn:hover {
  transform: translateY(-1px);
  border-color: rgba(37, 99, 235, 0.4);
  color: var(--accent-color-start);
}

.copy-code-btn.copied {
  background: rgba(37, 99, 235, 0.12);
  border-color: rgba(37, 99, 235, 0.4);
  color: var(--accent-color-start);
}

.copy-code-btn.error {
  background: rgba(239, 68, 68, 0.12);
  border-color: rgba(239, 68, 68, 0.4);
  color: #ef4444;
}

.copy-code-btn.error .copy-label {
  color: #ef4444;
}

.copy-inner {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.75rem;
  font-weight: 600;
}

.copy-icon {
  width: 16px;
  height: 16px;
}

.copy-icon--check {
  display: none;
}

.copy-code-btn.copied .copy-icon--copy {
  display: none;
}

.copy-code-btn.copied .copy-icon--check {
  display: block;
}

/* === ヘッダー & フッター === */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  padding: 0.75rem 0;
  transition: background-color 0.3s ease, border-color 0.3s ease;
}

body.dark-mode .site-header {
  background-color: rgba(13, 17, 23, 0.82);
}

.site-header .container,
.site-foot .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
}
.site-header h1 {
  margin: 0;
  font-size: 1.5rem;
}
.site-header h1 a {
  color: var(--heading-color);
  text-decoration: none;
}

.header-controls {
  display: flex;
  align-items: center;
  gap: clamp(0.75rem, 2vw, 1.25rem);
}

.site-nav {
  display: flex;
  align-items: center;
  position: relative;
}

.site-nav .nav-links {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.site-foot {
  margin-top: 3rem;
  padding: 2rem 0;
  font-size: 0.9rem;
  color: var(--quote-color);
}
.site-foot .container {
  text-align: center;
  display: block;
  border-top: 1px solid var(--border-color);
  padding-top: 2rem;
}
.footer-quote {
  font-style: italic;
  margin-bottom: 1rem;
}

/* === カードスタイル === */
.card {
  background-color: var(--card-bg-color);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: clamp(1.25rem, 3vw, 2rem);
  margin-bottom: 2rem;
  box-shadow: 0 18px 40px -24px var(--shadow-color);
  transition: background-color 0.3s, box-shadow 0.3s, border-color 0.3s, transform 0.3s;
}
.card:hover, .post-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 22px 48px -22px var(--shadow-color);
  border-color: rgba(37, 99, 235, 0.3);
}
.card .meta {
  margin: 1rem 0 1.5rem;
  color: var(--quote-color);
  font-size: 0.9rem;
}

/* === 記事ページレイアウト (single.html) === */
.article-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
  max-width: 1100px;
  margin: 0 auto;
  padding: 1.5rem 1rem;
}

@media (min-width: 1024px) {
  .article-layout {
    grid-template-columns: minmax(0, 3fr) 1fr;
  }
}

.article-content {
  background-color: var(--card-bg-color);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 2rem 2.5rem;
}

.share-buttons {
  margin-top: 2.5rem;
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
  padding: 1rem 1.25rem;
  background-color: color-mix(in srgb, var(--card-bg-color) 90%, var(--bg-color) 10%);
  border: 1px solid var(--border-color);
  border-radius: 12px;
}

.share-title {
  margin: 0;
  font-size: 1rem;
  color: var(--heading-color);
  font-weight: 600;
}

.share-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.55rem 1.1rem;
  border-radius: 999px;
  border: 1px solid rgba(37, 99, 235, 0.28);
  background: rgba(37, 99, 235, 0.12);
  color: var(--accent-color-start);
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: background-color 0.2s ease, border-color 0.2s ease, transform 0.2s ease;
}
.share-btn.discussion-btn {
  border-color: rgba(124, 58, 237, 0.28);
  background: rgba(124, 58, 237, 0.12);
  color: #7c3aed;
}
.share-btn.discussion-btn:hover {
  background: linear-gradient(90deg, #7c3aed, #2563eb);
  color: #fff;
  border-color: transparent;
}

.share-btn svg {
  width: 18px;
  height: 18px;
}

.share-btn:hover {
  transform: translateY(-1px);
  background: var(--accent-grad);
  border-color: transparent;
  color: #fff;
}

body.dark-mode .share-btn {
  background: rgba(48, 129, 247, 0.16);
  border-color: rgba(48, 129, 247, 0.36);
}

.article-header {
  margin-bottom: 2.5rem;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 1.5rem;
}
.article-header h1 {
  margin: 0 0 1rem;
  font-size: 2.5rem;
}
.article-meta {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.4rem;
  color: var(--quote-color);
  font-size: 0.95rem;
}
.article-author {
  color: var(--heading-color);
  font-weight: 600;
}

.article-sidebar {
  position: relative;
}
.toc-wrapper {
  position: sticky;
  top: 80px; /* ヘッダーの高さ + α */
  max-height: calc(100vh - 100px);
  overflow-y: auto;
  padding-right: 1rem;
}
.toc-wrapper h5 {
  margin: 0 0 1rem;
  font-size: 1rem;
  font-weight: 600;
  color: var(--heading-color);
}
.toc-wrapper nav ul {
  list-style: none;
  padding-left: 0;
}
.toc-wrapper nav > ul {
  padding-left: 0;
  border-left: 2px solid var(--border-color);
}
.toc-wrapper nav ul li {
  margin: 0.5rem 0;
}
.toc-wrapper nav ul li a {
  display: block;
  padding-left: 1rem;
  color: var(--quote-color);
  text-decoration: none;
  border-left: 2px solid transparent;
  margin-left: -2px;
  transition: all 0.2s;
}
.toc-wrapper nav ul li a:hover {
  color: var(--heading-color);
}
.toc-wrapper nav ul li.active > a {
  color: var(--accent-color-start);
  border-left-color: var(--accent-color-start);
  transform: translateX(3px);
}

@media (max-width: 1023px) {
  .article-layout {
    padding: clamp(1.25rem, 4vw, 2rem) clamp(1rem, 4vw, 2rem);
  }
}

@media (max-width: 900px) {
  .article-header h1 {
    font-size: 2.1rem;
  }
}

@media (max-width: 768px) {
  .article-layout {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }
  .article-sidebar {
    order: -1;
  }
  .toc-wrapper {
    position: static;
    max-height: none;
    padding-right: 0;
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1.25rem;
    background-color: var(--card-bg-color);
  }
}

@media (max-width: 640px) {
  .article-content {
    padding: 1.5rem;
  }
  .article-header h1 {
    font-size: 1.9rem;
  }
}

/* === 記事一覧ページ (list.html) === */
.list-header {
  margin-bottom: 3rem;
}
.list-header .list-title {
  font-size: 2.5rem;
  text-align: center;
  background: var(--accent-grad);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}



/* === トップページ特有のスタイル === */
.site-title-wrapper {
  text-align: center;
  margin: 2rem 0 3rem;
}
.site-title-wrapper .site-title {
  font-size: 3rem;
  font-weight: 700;
  background: var(--accent-grad);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.list-header .list-content {
  text-align: center;
}
.search-form-container {
  max-width: 420px;
  margin: 0 auto 2rem;
}
.search-input {
  width: 100%;
  padding: 0.75rem 1rem;
  font-size: 1rem;
  font-family: inherit;
  color: var(--text-color);
  background-color: var(--code-bg-color);
  border: 1px solid var(--border-color);
  border-radius: 6px;
  transition: border-color 0.2s, box-shadow 0.2s;
}
.search-input:focus {
  outline: none;
  border-color: var(--accent-color-start);
  box-shadow: 0 0 0 3px rgba(48, 129, 247, 0.3);
}
.hero h1 {
  font-size: 2.2rem;
  text-align: center;
}
.hero .lead {
  font-size: 1.2rem;
  text-align: center;
  color: var(--quote-color);
}
.hero-actions {
  margin-top: 1.75rem;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 1rem;
}
.cta-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.5rem;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.95rem;
  color: #fff;
  background: var(--accent-grad);
  border: none;
  box-shadow: 0 12px 25px -18px var(--shadow-color);
  transition: transform 0.2s ease, filter 0.2s ease;
}
.cta-button:hover {
  transform: translateY(-2px);
  filter: brightness(1.05);
}
.cta-button.secondary {
  background: transparent;
  color: var(--accent-color-start);
  border: 1px solid rgba(37, 99, 235, 0.35);
}
.cta-button.secondary:hover {
  background: rgba(37, 99, 235, 0.1);
}

.taxonomy-card {
  margin-top: 2.5rem;
}
.taxonomy-columns {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 2rem;
}
.taxonomy-block h2 {
  margin-top: 0;
  font-size: 1.35rem;
}
.taxonomy-text {
  margin: 0.35rem 0 1.25rem;
  color: var(--quote-color);
  font-size: 0.95rem;
}
.pill-group {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
}
.pill {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.45rem 0.95rem;
  border-radius: 999px;
  background: rgba(37, 99, 235, 0.12);
  border: 1px solid rgba(37, 99, 235, 0.28);
  color: var(--accent-color-start);
  font-size: 0.9rem;
  font-weight: 600;
  text-decoration: none;
  transition: transform 0.2s ease, background-color 0.2s ease;
}
.pill:hover {
  transform: translateY(-1px);
  background: var(--accent-grad);
  color: #fff;
  border-color: transparent;
}
.pill.secondary {
  background: rgba(124, 58, 237, 0.12);
  border: 1px solid rgba(124, 58, 237, 0.28);
}
.pill.secondary:hover {
  background: linear-gradient(90deg, #7c3aed, #2563eb);
}
.pill-count {
  font-size: 0.75rem;
  background: rgba(255, 255, 255, 0.22);
  padding: 0.1rem 0.45rem;
  border-radius: 999px;
  color: inherit;
}
.latest-posts {
  padding-top: 2rem;
  padding-bottom: 2rem;
}
.post-card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.5rem;  
  margin-top: 1.5rem;
}
.post-card {
  display: block;
  background-color: var(--card-bg-color);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: clamp(1.25rem, 3vw, 1.75rem);
  color: var(--text-color);
  text-decoration: none;
  box-shadow: 0 18px 40px -24px var(--shadow-color);
  transition: transform 0.3s, box-shadow 0.3s, border-color 0.3s;
}
.post-card h3 {
  margin: 0 0 0.5rem;
  font-size: 1.1rem;
  color: var(--heading-color);
}
.post-card p {
  margin: 0 0 1rem;
  font-size: 0.9rem;
}
.post-card .post-meta {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.85rem;
  color: var(--quote-color);
}
.post-card .post-author {
  color: var(--heading-color);
  font-weight: 600;
}
.meta-separator {
  color: var(--quote-color);
  display: inline-flex;
  align-items: center;
}
.no-results {
  grid-column: 1 / -1; /* グリッドの全幅を占める */
  text-align: center;
  padding: 2rem;
}

@media (max-width: 600px) {
  .post-card-grid {
    grid-template-columns: 1fr;
  }
  .post-card {
    padding: 1.5rem;
  }
  .site-title-wrapper .site-title {
    font-size: 2.35rem;
  }
}


/* === 引用 & コード === */
.quote, blockquote {
  margin: 2rem 0;
  padding: 1rem 1.5rem;
  border-left: 4px solid var(--accent-color-start);
  background-color: var(--code-bg-color);
  color: var(--quote-color);
  border-radius: 0 4px 4px 0;
}
.quote cite, blockquote cite {
  display: block;
  text-align: right;
  margin-top: 0.5rem;
  font-style: normal;
  font-size: 0.9em;
}

.pagination {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 3rem;
  padding: 1rem;
  border-top: 1px solid var(--border-color);
}
.pagination-item {
  color: var(--text-color);
  font-weight: 500;
}
.pagination-item.disabled {
  color: var(--quote-color);
  pointer-events: none;
  opacity: 0.6;
}
.page-number {
  color: var(--quote-color);
  font-size: 0.9rem;
}



.contact-form {
  margin-top: 2rem;
}

.form-group {
  margin-bottom: 1.5rem;
}

.form-group label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 500;
  color: var(--heading-color);
}

.form-group input[type="text"],
.form-group input[type="email"],
.form-group textarea {
  width: 100%;
  padding: 0.75rem 1rem;
  background-color: var(--code-bg-color);
  border: 1px solid var(--border-color);
  border-radius: 6px;
  color: var(--text-color);
  font-size: 1rem;
  font-family: inherit;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.form-group input[type="text"]:focus,
.form-group input[type="email"]:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--accent-color-start);
  box-shadow: 0 0 0 3px rgba(48, 129, 247, 0.3);
}

.btn-submit {
  display: inline-block;
  padding: 0.75rem 2rem;
  font-size: 1rem;
  font-weight: 600;
  color: #fff;
  background: var(--accent-grad);
  border: none;
  border-radius: 6px;
  cursor: pointer;
  transition: transform 0.2s, filter 0.2s;
}

.btn-submit:hover {
  filter: brightness(1.1);
  transform: translateY(-2px);
  text-decoration: none;
}
.form-group input[type="file"] {
  background-color: transparent;
  border: 1px solid var(--border-color);
  border-radius: 6px;
  padding: 0.5rem 1rem;
  width: 100%;
}
.form-note {
  margin: 0.25rem 0 0.75rem;
  font-size: 0.9rem;
  color: var(--quote-color);
}
.form-error {
  margin: 0 0 1rem;
  font-size: 0.95rem;
  font-weight: 500;
  color: #ff7b7b;
}
.form-group input[type="file"]::file-selector-button {
  background: var(--accent-grad);
  border: none;
  border-radius: 4px;
  color: #fff;
  padding: 0.5rem 1rem;
  margin-right: 1rem;
  cursor: pointer;
}


.address-box {
  background-color: var(--code-bg-color);
  border: 1px solid var(--border-color);
  border-radius: 4px;
  padding: 1rem;
  margin-bottom: 1rem;
}
.address-box label {
  display: block;
  font-weight: bold;
  color: var(--heading-color);
  margin-bottom: 0.5rem;
}
.address-box .addr {
  font-family: monospace;
  word-break: break-all;
  color: var(--text-color);
}

/* === ナビゲーション (ハンバーガーメニュー含む) === */
.site-nav a {
  color: var(--text-color);
  font-weight: 500;
}

.dark-mode-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  background: rgba(37, 99, 235, 0.08);
  color: var(--heading-color);
  border: 1px solid var(--border-color);
  border-radius: 999px;
  padding: 0.4rem 0.75rem;
  cursor: pointer;
  transition: background-color 0.2s ease, border-color 0.2s ease, color 0.2s ease;
}

body.dark-mode .dark-mode-btn {
  background: rgba(48, 129, 247, 0.12);
  color: var(--text-color);
}

.dark-mode-btn:hover {
  border-color: rgba(37, 99, 235, 0.4);
}

.dark-mode-btn svg {
  display: block;
}

.dark-mode-btn .moon-icon {
  display: none;
}

body.dark-mode .dark-mode-btn .sun-icon {
  display: none;
}

body.dark-mode .dark-mode-btn .moon-icon {
  display: block;
}
.hamburger-menu {
  display: none; /* PCでは非表示 */
  background: none;
  border: none;
  cursor: pointer;
  padding: 0;
}

/* レスポンシブ対応 */
@media (max-width: 768px) {
  .site-header .container {
    gap: 0.75rem;
  }
  .header-controls {
    gap: 0.75rem;
  }
  .site-nav .nav-links {
    display: none;
    position: absolute;
    top: calc(100% + 0.75rem);
    right: 0;
    width: min(90vw, 260px);
    padding: 1.25rem;
    background-color: var(--card-bg-color);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    box-shadow: 0 20px 45px -20px var(--shadow-color);
    z-index: 1200;
  }
  .site-nav .nav-links.active {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
  }
  .site-nav .nav-links a {
    display: block;
    margin: 0;
  }
  .hamburger-menu {
    display: block; /* SPで表示 */
    z-index: 1300;
  }
  .hamburger-icon {
    display: block;
    width: 24px;
    height: 2px;
    background-color: var(--text-color);
    position: relative;
  }
  .hamburger-icon::before,
  .hamburger-icon::after {
    content: '';
    position: absolute;
    width: 24px;
    height: 2px;
    background-color: var(--text-color);
    left: 0;
  }
  .hamburger-icon::before { top: -8px; }
  .hamburger-icon::after { bottom: -8px; }
}

/* アニメーション */
@keyframes aurora {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}