/* ==========================================================================
   AI仕事ラボ style.css
   優先順位: 読みやすさ > スマホ対応 > 速度 > SEO > 装飾。JavaScriptに極力依存しない。
   構成: 1.Tokens 2.Base 3.Layout/Utility 4.Header 5.Footer 6.Hero
         7.Category cards 8.Article cards 9.Page header/Breadcrumb/Pagination
         10.Article detail 11.FAQ/TOC/Author 12.Forms 13.Error pages
         14.Accessibility 15.Responsive
   ========================================================================== */

/* 1. Design tokens
   ------------------------------------------------------------------------ */
:root {
  --color-bg: #ffffff;
  --color-bg-alt: #f8fafc;
  --color-bg-dark: #0b1324;
  --color-text: #273449;
  --color-heading: #0f172a;
  --color-muted: #64748b;
  --color-border: #e2e8f0;
  --color-border-strong: #cbd5e1;
  --color-accent: #2354e6;
  --color-accent-dark: #1a3fb8;
  --color-accent-light: #eaf0fe;
  --color-on-accent: #ffffff;
  /* データセンター系の濃紺セクション(Hero/中央バナー/Footer)用。 */
  --color-navy-deep: #060a16;
  --color-on-dark: #eef1fb;
  --color-on-dark-muted: #a7b1d4;

  --content-width: 720px;
  --page-width: 1160px;

  --radius-sm: 6px;
  --radius: 12px;
  --radius-lg: 18px;

  --shadow-card: 0 1px 2px rgba(15, 23, 42, 0.06), 0 1px 3px rgba(15, 23, 42, 0.08);
  --shadow-card-hover: 0 8px 20px rgba(15, 23, 42, 0.12), 0 2px 6px rgba(15, 23, 42, 0.08);

  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 24px;
  --space-6: 32px;
  --space-7: 48px;
  --space-8: 64px;
}

/* 2. Base / Reset
   ------------------------------------------------------------------------ */
* {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Kaku Gothic ProN",
    "Hiragino Sans", "Yu Gothic", Meiryo, sans-serif;
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.85;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

h1, h2, h3, h4 {
  color: var(--color-heading);
  line-height: 1.4;
  font-weight: 700;
}

p {
  margin: 0 0 1em;
}

a {
  color: var(--color-accent);
  text-decoration: none;
}
a:hover {
  text-decoration: underline;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

ul, ol {
  padding-left: 1.4em;
}

/* 3. Layout / Utility
   ------------------------------------------------------------------------ */
main {
  max-width: var(--page-width);
  margin: 0 auto;
  padding: var(--space-5) var(--space-4) var(--space-8);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
  z-index: 100;
  background: var(--color-accent);
  color: #fff;
  padding: 10px 16px;
  border-radius: 0 0 8px 0;
}
.skip-link:focus {
  left: 0;
}

a:focus-visible,
button:focus-visible,
input:focus-visible,
summary:focus-visible {
  outline: 3px solid var(--color-accent);
  outline-offset: 2px;
  border-radius: 3px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 12px 22px;
  border-radius: 999px;
  font-weight: 700;
  font-size: 0.95rem;
  border: 1.5px solid transparent;
  cursor: pointer;
  white-space: nowrap;
}
.btn:hover {
  text-decoration: none;
}
.btn--primary {
  background: var(--color-accent);
  color: var(--color-on-accent);
}
.btn--primary:hover {
  background: var(--color-accent-dark);
}
.btn--ghost {
  background: #fff;
  color: var(--color-heading);
  border-color: var(--color-border-strong);
}
.btn--ghost:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.section {
  margin-top: var(--space-8);
}
.section__header {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-2) var(--space-4);
  margin-bottom: var(--space-5);
}
.section__header h2 {
  font-size: 1.5rem;
  margin: 0;
}
.section__note {
  color: var(--color-muted);
  font-size: 0.9rem;
  margin: 0;
}
.section__more {
  font-weight: 600;
  font-size: 0.9rem;
  white-space: nowrap;
}

.page-header {
  margin-bottom: var(--space-6);
  padding-bottom: var(--space-4);
  border-bottom: 1px solid var(--color-border);
}
.page-header h1 {
  font-size: 1.9rem;
  margin: 0 0 8px;
}
.page-header__lead {
  color: var(--color-muted);
  margin: 0;
}

.link-arrow {
  font-weight: 700;
}

/* 4. Header
   ------------------------------------------------------------------------ */
.site-header {
  border-bottom: 1px solid var(--color-border);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: saturate(180%) blur(6px);
  position: sticky;
  top: 0;
  z-index: 50;
}
.site-header__inner {
  max-width: var(--page-width);
  margin: 0 auto;
  padding: 12px 16px;
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--color-heading);
  flex-shrink: 0;
}
.brand:hover {
  text-decoration: none;
}
.brand__mark {
  flex-shrink: 0;
}
.brand__name {
  font-size: 1.15rem;
  font-weight: 800;
  letter-spacing: 0.01em;
}

.site-header__collapsible {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  flex: 1;
  min-width: 0;
}

.site-nav {
  flex: 1;
  min-width: 0;
}
.site-nav ul {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 4px 18px;
  margin: 0;
  padding: 0;
}
.site-nav a {
  color: var(--color-text);
  font-size: 0.92rem;
  font-weight: 600;
}
.site-nav a:hover {
  color: var(--color-accent);
  text-decoration: none;
}

.search-form {
  display: flex;
  gap: 0;
  margin-left: auto;
  border: 1.5px solid var(--color-border-strong);
  border-radius: 999px;
  overflow: hidden;
  flex-shrink: 0;
}
.search-form input[type="text"] {
  border: 0;
  padding: 8px 14px;
  font-size: 0.9rem;
  width: 180px;
  min-width: 0;
}
.search-form input[type="text"]:focus {
  outline: none;
}
.search-form button {
  border: 0;
  background: var(--color-bg-alt);
  color: var(--color-heading);
  padding: 0 14px;
  cursor: pointer;
  display: flex;
  align-items: center;
}
.search-form button:hover {
  background: var(--color-accent-light);
  color: var(--color-accent);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 4px;
  width: 40px;
  height: 40px;
  border: 1.5px solid var(--color-border-strong);
  border-radius: 8px;
  background: #fff;
  cursor: pointer;
  flex-shrink: 0;
}
.nav-toggle__bar {
  display: block;
  width: 18px;
  height: 2px;
  margin: 0 auto;
  background: var(--color-heading);
  border-radius: 2px;
}

/* 5. Footer
   ------------------------------------------------------------------------ */
.site-footer {
  border-top: none;
  background: var(--color-navy-deep);
  color: var(--color-on-dark-muted);
  margin-top: var(--space-8);
}
.site-footer__inner {
  max-width: var(--page-width);
  margin: 0 auto;
  padding: var(--space-7) var(--space-4) var(--space-5);
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: var(--space-6);
}
.site-footer__name {
  color: var(--color-on-dark);
  font-weight: 800;
  font-size: 1.1rem;
  margin: 0 0 6px;
}
.site-footer__tagline {
  margin: 0;
  font-size: 0.9rem;
}
.site-footer__heading {
  color: var(--color-on-dark);
  font-weight: 700;
  font-size: 0.85rem;
  margin: 0 0 10px;
}
.site-footer__nav ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.site-footer__nav a {
  color: var(--color-on-dark-muted);
  font-size: 0.9rem;
}
.site-footer__nav a:hover {
  color: #8fb0ff;
}
.site-footer__bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  padding: var(--space-4);
  text-align: center;
  font-size: 0.8rem;
  color: var(--color-on-dark-muted);
}
.site-footer__bottom p {
  margin: 0;
}

/* 6. Hero(データセンター実写を背景に使うフルブリードHero)
   ------------------------------------------------------------------------ */
.hero {
  position: relative;
  margin: 0 calc(-1 * var(--space-4)) 0;
  border-radius: 0 0 var(--radius-lg) var(--radius-lg);
  overflow: hidden;
  background: var(--color-navy-deep);
  min-height: 480px;
  display: flex;
  align-items: center;
}
.hero__bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  z-index: 0;
}
/* 写真の上に濃紺スクリムを重ね、左側のテキストの可読性を確保する。 */
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  background:
    linear-gradient(100deg, rgba(6, 10, 22, 0.93) 0%, rgba(6, 10, 22, 0.8) 34%, rgba(6, 10, 22, 0.32) 58%, rgba(6, 10, 22, 0.08) 100%);
}
/* AIインフラ感を演出する非常に薄いグリッド(SF演出ではなく実在のラック配線をイメージ)。 */
.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  opacity: 0.12;
  background-image:
    repeating-linear-gradient(90deg, rgba(120, 160, 255, 0.35) 0, rgba(120, 160, 255, 0.35) 1px, transparent 1px, transparent 64px),
    repeating-linear-gradient(0deg, rgba(120, 160, 255, 0.35) 0, rgba(120, 160, 255, 0.35) 1px, transparent 1px, transparent 64px);
}
.hero__inner {
  position: relative;
  z-index: 2;
  max-width: var(--page-width);
  margin: 0 auto;
  padding: var(--space-8) var(--space-4);
  width: 100%;
}
.hero__text {
  max-width: 640px;
}
.hero__eyebrow {
  color: #8fb0ff;
  font-weight: 700;
  font-size: 0.85rem;
  letter-spacing: 0.06em;
  margin: 0 0 14px;
}
.hero__title {
  color: var(--color-on-dark);
  font-size: clamp(2.1rem, 4.4vw, 3rem);
  margin: 0 0 18px;
  line-height: 1.3;
  text-shadow: 0 2px 16px rgba(0, 0, 0, 0.35);
}
.hero__lead {
  color: var(--color-on-dark-muted);
  font-size: 1.08rem;
  margin: 0 0 30px;
  max-width: 46ch;
}
.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}
.hero__actions .btn--ghost {
  background: rgba(255, 255, 255, 0.06);
  color: var(--color-on-dark);
  border-color: rgba(255, 255, 255, 0.35);
}
.hero__actions .btn--ghost:hover {
  background: rgba(255, 255, 255, 0.14);
  border-color: #8fb0ff;
  color: #ffffff;
}

/* 7. Category cards
   ------------------------------------------------------------------------ */
.category-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: var(--space-4);
}
.category-card {
  position: relative;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  min-height: 200px;
  padding: var(--space-5);
  border-radius: var(--radius);
  color: #fff;
  box-shadow: var(--shadow-card);
  overflow: hidden;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}
.category-card:hover {
  text-decoration: none;
  transform: translateY(-2px);
  box-shadow: var(--shadow-card-hover);
}
.category-card__media {
  position: absolute;
  inset: 0;
  z-index: 0;
  background: var(--color-navy-deep);
}
.category-card__media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}
/* 写真の上に濃紺グラデーションを重ね、下部のテキストを読みやすくする。 */
.category-card::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  background: linear-gradient(180deg, rgba(6, 10, 22, 0.1) 0%, rgba(6, 10, 22, 0.55) 55%, rgba(6, 10, 22, 0.92) 100%);
}
.category-card__body {
  position: relative;
  z-index: 2;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.category-card__icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, 0.16);
  color: #fff;
}
.category-card__name {
  color: #fff;
  font-weight: 700;
  font-size: 1.05rem;
}
.category-card__desc {
  color: rgba(238, 241, 251, 0.86);
  font-size: 0.85rem;
  line-height: 1.6;
}

/* 7.5 データセンター実写バナー(新着記事とAI仕事ラボについての間に挿入する中間ビジュアル)
   ------------------------------------------------------------------------ */
.dc-banner {
  position: relative;
  margin: var(--space-8) calc(-1 * var(--space-4)) 0;
  overflow: hidden;
  background: var(--color-navy-deep);
  min-height: 320px;
  display: flex;
  align-items: center;
}
.dc-banner__bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  z-index: 0;
}
/* Heroと同じ手法: 左側は文字の可読性を確保しつつ、右側は写真をはっきり見せる横方向の
   グラデーション(モックアップ参考、写真がほぼ見えない縦方向グラデーションから変更)。 */
.dc-banner::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  background: linear-gradient(100deg, rgba(6, 10, 22, 0.88) 0%, rgba(6, 10, 22, 0.68) 32%, rgba(6, 10, 22, 0.22) 60%, rgba(6, 10, 22, 0.05) 100%);
}
.dc-banner__inner {
  position: relative;
  z-index: 2;
  max-width: var(--page-width);
  margin: 0 auto;
  padding: var(--space-7) var(--space-4);
  width: 100%;
}
.dc-banner__text {
  max-width: 620px;
  text-align: left;
}
.dc-banner__title {
  color: #ffffff;
  font-size: clamp(1.5rem, 3.2vw, 2.1rem);
  margin: 0 0 14px;
  text-shadow: 0 2px 16px rgba(0, 0, 0, 0.35);
}
.dc-banner__lead {
  color: #ffffff;
  font-size: 1.02rem;
  line-height: 1.8;
  margin: 0;
  max-width: 52ch;
}

/* legacy: カテゴリー詳細ページの子カテゴリー一覧(シンプルなリンクリスト) */
.category-list {
  list-style: none;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 12px;
  margin: 0 0 var(--space-6);
}
.category-list a {
  display: block;
  padding: 14px;
  background: var(--color-bg-alt);
  border-radius: var(--radius-sm);
  color: var(--color-text);
  font-weight: 600;
}
.category-list a:hover {
  text-decoration: none;
  background: var(--color-accent-light);
  color: var(--color-accent);
}

/* 8. Article cards
   ------------------------------------------------------------------------ */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: var(--space-5);
}
.card {
  position: relative;
  display: flex;
  flex-direction: column;
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-card);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}
.card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-card-hover);
}
.card__thumb-link {
  position: relative;
  display: block;
  background: var(--color-bg-alt);
}
.card__thumb {
  width: 100%;
  aspect-ratio: 3 / 2;
  object-fit: cover;
}
.card__thumb--placeholder {
  display: block;
  width: 100%;
  aspect-ratio: 3 / 2;
  background: linear-gradient(135deg, var(--color-accent-light), var(--color-bg-alt));
}
.card__body {
  padding: var(--space-4);
  display: flex;
  flex-direction: column;
  gap: 6px;
  flex: 1;
}
/* 記事カードのカテゴリーラベルは、サムネイル写真に重ねるカラーバッジとして表示する。
   色はカテゴリーごとに変えるが、実在する5カテゴリーの識別用であり架空の数値・実績は含まない。 */
.card__badge {
  position: absolute;
  z-index: 2;
  left: 12px;
  bottom: 12px;
  margin: 0;
  padding: 4px 12px;
  border-radius: 999px;
  color: #fff;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  background: var(--color-heading);
}
.card__badge--ai-tools {
  background: #2f6fed;
}
.card__badge--ai-work {
  background: #d97a2f;
}
.card__badge--ai-sidejob {
  background: #2fa876;
}
.card__badge--career {
  background: #6a5cd0;
}
.card__badge--web-creation {
  background: #1a2b52;
}
.card__title {
  margin: 0;
  font-size: 1.05rem;
  line-height: 1.5;
}
.card__link {
  color: var(--color-heading);
}
.card__link:hover {
  color: var(--color-accent);
}
/* カード全体をクリック可能にしつつ、視覚的なリンクはタイトルのみに絞る
   (stretched-linkパターン。card__thumb-linkはaria-hidden+tabindex=-1で
   スクリーンリーダー・キーボード操作からは除外し、リンクの重複読み上げを防ぐ)。 */
.card__link::after {
  content: "";
  position: absolute;
  inset: 0;
}
.card__excerpt {
  margin: 0;
  color: var(--color-muted);
  font-size: 0.88rem;
  line-height: 1.7;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.card__meta {
  margin: auto 0 0;
  color: var(--color-muted);
  font-size: 0.78rem;
}

/* 9. Breadcrumb / Pagination
   ------------------------------------------------------------------------ */
.breadcrumb {
  font-size: 0.82rem;
  color: var(--color-muted);
  margin: var(--space-4) 0;
}
.breadcrumb ol {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  padding: 0;
  margin: 0;
}
.breadcrumb li:not(:last-child)::after {
  content: "/";
  padding: 0 6px;
  color: var(--color-border-strong);
}
.breadcrumb a {
  color: var(--color-muted);
}
.breadcrumb a:hover {
  color: var(--color-accent);
}

.pagination {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-top: var(--space-6);
  justify-content: center;
  font-size: 0.9rem;
}
.pagination a {
  font-weight: 700;
}

/* 10. Article detail
   ------------------------------------------------------------------------ */
.article-layout {
  display: flex;
  justify-content: center;
}
.article-content {
  max-width: var(--content-width);
  width: 100%;
}

.article-header__category a {
  display: inline-block;
  color: var(--color-accent);
  font-weight: 700;
  font-size: 0.82rem;
  background: var(--color-accent-light);
  padding: 4px 12px;
  border-radius: 999px;
  margin-bottom: 12px;
}
.article-header h1 {
  font-size: clamp(1.5rem, 3.2vw, 2.1rem);
  margin: 0 0 12px;
}
.article-header__lead {
  color: var(--color-muted);
  font-size: 1.02rem;
  margin: 0 0 14px;
}

.article-meta {
  color: var(--color-muted);
  font-size: 0.85rem;
  margin: 0 0 var(--space-5);
  display: flex;
  flex-wrap: wrap;
  gap: 4px 14px;
}
.article-meta time,
.article-meta__author {
  white-space: nowrap;
}

.article-eyecatch {
  width: 100%;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  border-radius: var(--radius);
  margin: 0 0 var(--space-6);
}

.article-body {
  margin-top: var(--space-5);
}
.article-body h2 {
  font-size: 1.35rem;
  margin-top: 2.2em;
  margin-bottom: 0.8em;
  padding-left: 14px;
  border-left: 5px solid var(--color-accent);
  scroll-margin-top: 90px;
}
.article-body h3 {
  font-size: 1.1rem;
  margin-top: 1.8em;
  margin-bottom: 0.6em;
  scroll-margin-top: 90px;
}
.article-body p {
  margin: 0 0 1.2em;
}
.article-body ul,
.article-body ol {
  margin: 0 0 1.2em;
  padding-left: 1.6em;
}
.article-body li {
  margin-bottom: 0.4em;
}
.article-body strong {
  color: var(--color-heading);
}
.article-body blockquote {
  margin: 1.4em 0;
  padding: 4px 20px;
  border-left: 4px solid var(--color-border-strong);
  color: var(--color-muted);
  background: var(--color-bg-alt);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}
.article-body pre {
  background: #0f172a;
  color: #e2e8f0;
  padding: 16px;
  overflow-x: auto;
  border-radius: var(--radius-sm);
  font-size: 0.86rem;
  line-height: 1.6;
}
.article-body code {
  background: var(--color-bg-alt);
  padding: 0.15em 0.4em;
  border-radius: 4px;
  font-size: 0.9em;
}
.article-body pre code {
  background: none;
  padding: 0;
}
.article-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.4em 0;
  font-size: 0.92rem;
  display: block;
  overflow-x: auto;
}
.article-body th,
.article-body td {
  border: 1px solid var(--color-border);
  padding: 10px 12px;
  text-align: left;
}
.article-body th {
  background: var(--color-bg-alt);
  color: var(--color-heading);
  white-space: nowrap;
}
.article-body a {
  text-decoration: underline;
  text-underline-offset: 2px;
}

/* 11. TOC / FAQ / Author box / Preview banner
   ------------------------------------------------------------------------ */
.toc {
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: var(--space-4) var(--space-5);
  margin: 0 0 var(--space-6);
}
.toc__summary {
  cursor: pointer;
  font-weight: 700;
  color: var(--color-heading);
  list-style: none;
}
.toc__summary::-webkit-details-marker {
  display: none;
}
.toc__summary::before {
  content: "▸";
  display: inline-block;
  margin-right: 8px;
  color: var(--color-accent);
  transition: transform 0.15s ease;
}
.toc[open] > .toc__summary::before {
  transform: rotate(90deg);
}
.toc__list {
  list-style: none;
  margin: var(--space-3) 0 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.toc__item a {
  color: var(--color-text);
  font-size: 0.92rem;
}
.toc__item a:hover {
  color: var(--color-accent);
}
.toc__item--level3 {
  padding-left: 1.4em;
  font-size: 0.88rem;
}

.faq-block {
  margin-top: var(--space-7);
}
.faq-block h2 {
  font-size: 1.35rem;
  margin-bottom: var(--space-4);
}
.faq-item {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 14px 18px;
  margin-bottom: 10px;
}
.faq-item summary {
  cursor: pointer;
  font-weight: 700;
  color: var(--color-heading);
  list-style: none;
}
.faq-item summary::-webkit-details-marker {
  display: none;
}
.faq-item summary::before {
  content: "Q.";
  color: var(--color-accent);
  margin-right: 8px;
}
.faq-item p {
  margin: 10px 0 0;
  color: var(--color-text);
  padding-left: 1.6em;
}

.affiliate-cta {
  position: relative;
  margin-top: var(--space-7);
  padding: var(--space-5) var(--space-5) var(--space-5);
  background: #fff;
  border: 1.5px solid var(--color-border-strong);
  border-radius: var(--radius);
}
.affiliate-cta__badge {
  position: absolute;
  top: -10px;
  left: var(--space-5);
  background: var(--color-heading);
  color: #fff;
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  padding: 2px 10px;
  border-radius: 999px;
}
.affiliate-cta__name {
  margin: 6px 0 8px;
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--color-heading);
}
.affiliate-cta__desc {
  margin: 0 0 10px;
  color: var(--color-text);
  font-size: 0.92rem;
  line-height: 1.7;
}
.affiliate-cta__campaign {
  margin: 0 0 10px;
  color: var(--color-accent-dark);
  font-size: 0.84rem;
  font-weight: 700;
}
.affiliate-cta__condition {
  margin: 0 0 14px;
  padding: 8px 12px;
  background: var(--color-bg-alt);
  border-radius: var(--radius-sm);
  color: var(--color-muted);
  font-size: 0.82rem;
  line-height: 1.6;
}
.affiliate-cta__button {
  width: 100%;
  justify-content: center;
  text-align: center;
}

/* A8.net「通常広告」(バナー/テキストのHTMLコードをそのまま出力)向け。中身(cta.a8_html)自体は
   一切書き換えないが、幅の大きい固定サイズ画像がスマホ幅を超えてはみ出さないよう、CSS側で
   表示だけ縮小する(HTML属性のwidth/heightそのものは変更しない)。 */
.affiliate-cta--a8 .affiliate-cta__a8-html {
  margin-top: 8px;
  text-align: center;
  overflow-x: auto;
}
.affiliate-cta--a8 .affiliate-cta__a8-html img {
  max-width: 100%;
  height: auto;
}

.author-box {
  margin-top: var(--space-7);
  padding: var(--space-5);
  background: var(--color-bg-alt);
  border-radius: var(--radius);
  border: 1px solid var(--color-border);
}
.author-box__label {
  margin: 0 0 4px;
  color: var(--color-muted);
  font-size: 0.78rem;
  font-weight: 700;
}
.author-box__name {
  margin: 0 0 6px;
  font-weight: 700;
  color: var(--color-heading);
}
.author-box__bio {
  margin: 0;
  color: var(--color-text);
  font-size: 0.92rem;
}

.about-box {
  display: grid;
  grid-template-columns: 1fr 1.3fr;
  gap: var(--space-6);
  align-items: center;
  background: var(--color-bg-alt);
  border-radius: var(--radius-lg);
  padding: var(--space-7) var(--space-6);
  text-align: left;
  overflow: hidden;
}
.about-box__media {
  display: block;
  border-radius: var(--radius);
  overflow: hidden;
  aspect-ratio: 4 / 3;
}
.about-box__media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}
.about-box h2 {
  margin-top: 0;
}
.about-box p {
  max-width: 68ch;
}
.about-box__points {
  list-style: none;
  margin: var(--space-4) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(180px, 1fr));
  gap: 10px 20px;
}
.about-box__points li {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--color-text);
  font-size: 0.88rem;
}
.about-box__points-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 26px;
  height: 26px;
  flex-shrink: 0;
  border-radius: 999px;
  background: var(--color-accent-light);
  color: var(--color-accent);
}

.preview-banner {
  background: #fff8e1;
  border: 1px solid #e0c341;
  color: #6b5900;
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  margin-bottom: var(--space-5);
  font-size: 0.9rem;
}

/* 12. Forms
   ------------------------------------------------------------------------ */
.search-form-page {
  display: flex;
  gap: 10px;
  margin: var(--space-2) 0 var(--space-6);
}
.search-form-page input[type="text"] {
  flex: 1;
  max-width: 420px;
  padding: 12px 16px;
  font-size: 1rem;
  border: 1.5px solid var(--color-border-strong);
  border-radius: 999px;
}
.search-form-page button {
  padding: 0 22px;
  border: 0;
  background: var(--color-accent);
  color: #fff;
  border-radius: 999px;
  font-weight: 700;
  cursor: pointer;
}
.search-form-page button:hover {
  background: var(--color-accent-dark);
}

/* 13. Error pages
   ------------------------------------------------------------------------ */
.error-page {
  text-align: center;
  padding: var(--space-8) 16px;
}
.error-page h1 {
  font-size: 3rem;
  color: var(--color-accent);
  margin-bottom: 8px;
}

/* 14. Utility
   ------------------------------------------------------------------------ */
.disclosure-note {
  font-size: 0.85rem;
  color: var(--color-muted);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 10px 14px;
  margin-bottom: 20px;
}

/* 15. Responsive
   ------------------------------------------------------------------------ */
@media (max-width: 960px) {
  .site-footer__inner {
    grid-template-columns: 1fr 1fr;
  }
  .site-footer__brand {
    grid-column: 1 / -1;
  }
  .about-box {
    grid-template-columns: 1fr;
  }
  .about-box__media {
    aspect-ratio: 16 / 9;
  }
}

@media (max-width: 760px) {
  .nav-toggle {
    display: flex;
  }
  .site-header__collapsible {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: #fff;
    border-bottom: 1px solid var(--color-border);
    padding: var(--space-4);
    flex-direction: column;
    align-items: stretch;
    gap: var(--space-4);
  }
  .site-header__collapsible.is-open {
    display: flex;
  }
  .site-nav ul {
    flex-direction: column;
    gap: 10px;
  }
  .search-form {
    width: 100%;
  }
  .search-form input[type="text"] {
    width: auto;
    flex: 1;
  }

  .hero {
    margin: 0 calc(-1 * var(--space-4));
    border-radius: 0;
    min-height: 420px;
  }
  .hero__inner {
    padding: var(--space-6) var(--space-4);
  }
  .hero__actions .btn {
    flex: 1;
    justify-content: center;
  }

  .dc-banner {
    margin: var(--space-6) calc(-1 * var(--space-4)) 0;
    min-height: 240px;
  }
  .dc-banner__inner {
    padding: var(--space-6) var(--space-4);
  }

  .site-footer__inner {
    grid-template-columns: 1fr;
    gap: var(--space-5);
  }

  main {
    padding: var(--space-4) 16px var(--space-7);
  }
}

@media (max-width: 600px) {
  body {
    font-size: 15px;
  }
  .article-header h1 {
    font-size: 1.5rem;
  }
  .about-box {
    padding: var(--space-5);
  }
  .about-box__points {
    grid-template-columns: 1fr;
  }
}