/* ─────────────────────────────────────────────
   産学連携トレンド・レター（公開版）共通スタイル
   コーポレートサイト index.html のパレットに準拠
   ───────────────────────────────────────────── */

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

:root {
  --off-white: #ffffff;
  --cream: #faf8f4;
  --ink-blue: #1a1f2e;
  --gold: #b8964a;
  --gold-light: #d4af6e;
  --text-body: #3d4354;
  --text-muted: #6b7280;
  --border: rgba(26, 31, 46, 0.12);
  --border-soft: rgba(26, 31, 46, 0.07);
}

html { scroll-behavior: smooth; }

body {
  background-color: var(--off-white);
  color: var(--ink-blue);
  font-family: 'Noto Sans JP', sans-serif;
  font-weight: 300;
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
}

/* ─── NAV ─── */
nav.site {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: rgba(250, 248, 244, 0.95);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: 1160px; margin: 0 auto; padding: 0 40px; height: 68px;
  display: flex; align-items: center; justify-content: space-between;
}
.nav-logo { display: flex; align-items: center; gap: 12px; text-decoration: none; }
.logo-text {
  font-family: 'Lexend Deca', sans-serif; font-size: 1.9rem; font-weight: 500;
  letter-spacing: -0.01em; color: #1f0acc;
}
.logo-sub {
  font-family: 'Inter', sans-serif; font-size: 0.72rem; font-weight: 400;
  letter-spacing: 0.06em; color: var(--text-muted);
}
.nav-links { display: flex; gap: 34px; list-style: none; }
.nav-links a {
  font-size: 0.78rem; letter-spacing: 0.08em; color: var(--ink-blue);
  text-decoration: none; font-weight: 400; transition: color 0.2s;
}
.nav-links a:hover, .nav-links a.current { color: var(--gold); }

/* ─── LAYOUT ─── */
.wrap { max-width: 820px; margin: 0 auto; padding: 0 24px; }
/* コンテンツ幅をコーポレートサイト／研QのLPと揃える（内側1160px） */
.wrap.wide { max-width: 1240px; padding: 0 40px; }
.wide .lead-text { max-width: none; font-size: 0.89rem; text-wrap: balance; }
.header-note { margin-top: 14px; font-size: 0.82rem; color: var(--text-muted); letter-spacing: 0.03em; }
.header-note a { color: var(--ink-blue); text-decoration: none; border-bottom: 1px solid var(--gold); padding-bottom: 1px; }
.header-note a:hover { color: var(--gold); }
.signup { scroll-margin-top: 90px; }
.narrow { max-width: 760px; margin: 0 auto; }

/* ─── ARTICLE HEADER ─── */
header.article {
  background: var(--off-white);
  padding: 128px 0 8px;
}
/* 一覧・タグページ：直下のタグパネル（クリーム）と色が続かないよう白地にする */
header.article.plain {
  background: var(--off-white);
  border-bottom: 1px solid var(--border-soft);
  padding: 112px 0 26px;
}
header.article.plain + main.wrap { padding-top: 32px; }
.filters .label { margin-bottom: 0; }
.breadcrumb { font-size: 0.72rem; letter-spacing: 0.06em; color: var(--text-muted); margin-bottom: 26px; }
.breadcrumb a { color: var(--text-muted); text-decoration: none; }
.breadcrumb a:hover { color: var(--gold); }

h1 { font-size: 1.95rem; font-weight: 700; line-height: 1.55; letter-spacing: 0.01em; margin: 22px 0 28px; }

.article-meta {
  display: flex; flex-wrap: wrap; align-items: center; gap: 14px;
  font-size: 0.74rem; color: var(--text-muted); letter-spacing: 0.04em;
}
.article-meta a { color: var(--text-muted); text-decoration: none; border-bottom: 1px solid var(--border); }
.article-meta a:hover { color: var(--gold); }

/* ─── TAGS ─── */
.taglist { display: flex; flex-wrap: wrap; gap: 8px; }
.tag {
  display: inline-block; font-size: 0.68rem; letter-spacing: 0.06em;
  padding: 4px 11px; border-radius: 3px; white-space: nowrap; text-decoration: none;
  border: 1px solid var(--border); color: var(--text-muted); background: #fff;
  transition: border-color 0.2s, color 0.2s;
}
a.tag:hover { border-color: var(--gold); color: var(--gold); }
.tag-actor { border-color: rgba(184,150,74,0.45); color: #8a6f31; background: rgba(184,150,74,0.08); font-weight: 500; }
.tag-form  { border-color: rgba(26,31,46,0.2); color: var(--ink-blue); }

/* ─── BODY ─── */
main.wrap { padding-top: 64px; }
.label {
  font-family: 'Inter', sans-serif; font-size: 0.62rem; font-weight: 700;
  letter-spacing: 0.2em; color: var(--gold); margin-bottom: 20px;
}
.facts { font-size: 0.95rem; line-height: 2.15; color: var(--text-body); }

/* 「何があったか」＝他社記事にもとづく事実。色を敷いて解説（自社の見解）と区別する */
.facts-box {
  background: var(--cream);
  border: 1px solid var(--border-soft);
  border-radius: 4px;
  padding: 30px 34px;
}
.facts-box .label { margin-bottom: 16px; }
.facts-box .source { margin-top: 22px; padding-top: 18px; border-top: 1px dotted rgba(26,31,46,0.18); }
.source {
  font-size: 0.74rem; letter-spacing: 0.04em; color: var(--text-muted);
  margin-top: 26px; padding-top: 22px; border-top: 1px dotted var(--border);
}
.source a { color: var(--gold); text-decoration: none; border-bottom: 1px solid rgba(184,150,74,0.35); }
.source a:hover { border-bottom-color: var(--gold); }

.take { margin-top: 64px; }
.take p { font-size: 0.97rem; line-height: 2.2; color: var(--text-body); margin-bottom: 1.8em; }
.take p:last-child { margin-bottom: 0; }
.take strong { font-weight: 600; color: var(--ink-blue); }

/* ─── TAG FOOTER ─── */
.tag-footer { margin-top: 72px; padding-top: 32px; border-top: 1px solid var(--border-soft); }
.tag-footer .label { margin-bottom: 14px; }

/* ─── CTA ─── */
.cta { margin-top: 64px; padding: 32px 34px; border: 1px solid var(--border); border-radius: 4px; background: var(--cream); }
.cta h2 { font-size: 1.22rem; font-weight: 700; line-height: 1.55; margin-bottom: 10px; }
.cta-sub { font-size: 0.8rem; font-weight: 600; color: var(--gold); letter-spacing: 0.03em; }
.cta p { font-size: 0.86rem; line-height: 1.95; color: var(--text-body); margin-bottom: 22px; }
.cta-grid, .signup-grid { display: grid; grid-template-columns: 1fr; gap: 20px; }
.cta-head .cta-sub { margin-bottom: 0; }
.btn {
  display: inline-block; background: var(--gold-light); color: var(--ink-blue);
  font-size: 0.82rem; font-weight: 600; letter-spacing: 0.05em;
  padding: 13px 32px; border-radius: 3px; text-decoration: none; transition: background 0.2s;
}
.btn:hover { background: var(--gold); }

/* ─── NEWSLETTER ─── */
.signup { margin-top: 64px; padding-top: 44px; border-top: 1px solid var(--border); }
.signup h2 { font-size: 1.18rem; font-weight: 700; line-height: 1.5; margin-bottom: 14px; }
.signup p { font-size: 0.88rem; line-height: 2; color: var(--text-body); margin-bottom: 0; }

/* 広いページ（一覧・タグ）では2カラムにして横幅を使う */
@media (min-width: 1000px) {
  .wide .cta { padding: 34px 38px; }
  .wide .cta-grid { grid-template-columns: 400px 1fr; gap: 40px; align-items: center; }
  .wide .signup-grid { grid-template-columns: 1fr 420px; gap: 56px; align-items: start; }
}

/* Benchmark の登録フォームは iframe 内で描画されるため、
   見た目（ボタン色・フォント等）は Benchmark のフォームデザイナー側で設定する。
   ここからは上書きできない。 */

/* ─── FOOTER ─── */
footer { margin-top: 88px; background: #0f1218; padding: 44px 0; }
.footer-inner {
  max-width: 1160px; margin: 0 auto; padding: 0 40px;
  display: flex; align-items: center; justify-content: space-between; gap: 24px; flex-wrap: wrap;
}
.footer-logo { font-family: 'Inter', sans-serif; font-size: 0.8rem; letter-spacing: 0.06em; color: rgba(250,248,244,0.5); }
.footer-links { display: flex; align-items: center; gap: 28px; flex-wrap: wrap; }
.footer-links a, .footer-copy {
  font-size: 0.68rem; letter-spacing: 0.08em; color: rgba(250,248,244,0.4);
  text-decoration: none; transition: color 0.2s;
}
.footer-links a:hover { color: rgba(250,248,244,0.8); }

@media (max-width: 900px) {
  .nav-inner { padding: 0 24px; height: 60px; }
  .nav-links { display: none; }
  .logo-text { font-size: 1.5rem; }
  header.article { padding: 104px 0 8px; }
  .facts-box { padding: 24px 22px; }
  h1 { font-size: 1.45rem; }
  .cta { padding: 32px 24px; }
  .footer-inner { padding: 0 24px; flex-direction: column; align-items: flex-start; }
}

/* ─── 一覧・タグページ ─── */
.filters { margin-bottom: 32px; padding: 18px 24px; background: var(--cream); border: 1px solid var(--border-soft); border-radius: 4px; }
.filter-head { display: flex; align-items: center; justify-content: space-between; margin-bottom: 12px; }
.clear {
  background: none; border: none; cursor: pointer; font-family: inherit;
  font-size: 0.72rem; letter-spacing: 0.04em; color: var(--text-muted);
  border-bottom: 1px solid var(--border); padding: 0 0 2px;
}
.clear:hover { color: var(--gold); border-bottom-color: var(--gold); }
.filter-row { display: flex; gap: 14px; align-items: flex-start; margin-bottom: 8px; }
.filter-row:last-child { margin-bottom: 0; }
.filter-label {
  flex: 0 0 58px; font-size: 0.68rem; color: var(--text-muted);
  letter-spacing: 0.06em; padding-top: 4px;
}
.filter-row .taglist { gap: 5px; }
button.filter { cursor: pointer; font-family: inherit; padding: 3px 10px; }
button.filter.on { background: var(--ink-blue) !important; border-color: var(--ink-blue) !important; color: #fff !important; }

.count { font-size: 0.74rem; color: var(--text-muted); letter-spacing: 0.06em; margin-bottom: 16px; }
.empty { font-size: 0.86rem; color: var(--text-muted); padding: 32px 0; }

.cards { display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px; align-items: stretch; grid-auto-rows: 1fr; }
a.card {
  display: flex; flex-direction: column; text-decoration: none; color: inherit;
  padding: 22px 24px; border: 1px solid var(--border-soft); border-radius: 4px;
  transition: border-color 0.2s, background 0.2s;
}
a.card[hidden] { display: none; }
a.card:hover { border-color: var(--gold); background: var(--cream); }
.card-tags { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 12px; }
.card-title { font-size: 0.98rem; font-weight: 600; line-height: 1.6; margin-bottom: 10px; }
.card-desc {
  font-size: 0.8rem; line-height: 1.9; color: var(--text-muted);
  margin-bottom: 16px;
  display: -webkit-box; -webkit-line-clamp: 3; -webkit-box-orient: vertical; overflow: hidden;
}
.card-date { font-size: 0.72rem; color: var(--text-muted); letter-spacing: 0.05em; margin-top: auto; }

.backlink { margin-top: 32px; font-size: 0.82rem; }
.backlink a { color: var(--ink-blue); text-decoration: none; border-bottom: 1px solid var(--border); }
.backlink a:hover { color: var(--gold); border-bottom-color: var(--gold); }

@media (max-width: 1000px) {
  .cards { grid-template-columns: 1fr; }
}
@media (max-width: 900px) {
  .wrap.wide { padding: 0 24px; }
  .filters { padding: 18px; }
  .filter-row { flex-direction: column; gap: 6px; }
  .filter-label { flex: none; padding-top: 0; }
  a.card { padding: 20px; }
}

/* ─── 本文中のリンク ─── */
.inline-link {
  color: var(--ink-blue);
  text-decoration: none;
  border-bottom: 1px solid var(--gold);
  padding-bottom: 1px;
  transition: color 0.2s, background 0.2s;
}
.inline-link:hover { color: var(--gold); }
.facts-box .inline-link { border-bottom-color: rgba(184,150,74,0.7); }

/* ─── 参考リンクのカード ─── */
a.ref-card {
  display: flex; align-items: center; gap: 20px;
  text-decoration: none; color: inherit;
  border: 1px solid var(--border); border-radius: 6px;
  padding: 22px 24px; margin: 2.2em 0;
  transition: border-color 0.2s, background 0.2s, box-shadow 0.2s;
}
a.ref-card:hover {
  border-color: var(--gold);
  background: var(--cream);
  box-shadow: 0 2px 10px rgba(26,31,46,0.05);
}
.ref-card-body { flex: 1; min-width: 0; }
.ref-card-title {
  font-size: 0.95rem; font-weight: 600; line-height: 1.6; color: var(--ink-blue);
}
.ref-card-note {
  font-size: 0.8rem; line-height: 1.8; color: var(--text-muted); margin-top: 7px;
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden;
}
.ref-card-meta {
  font-size: 0.72rem; letter-spacing: 0.04em; color: var(--text-muted); margin-top: 10px;
}
.ref-card-arrow {
  flex: 0 0 auto; font-size: 1rem; color: var(--gold);
  transition: transform 0.2s;
}
a.ref-card:hover .ref-card-arrow { transform: translateX(3px); }
.facts-box a.ref-card { background: #fff; }
.facts-box a.ref-card:hover { background: #fff; border-color: var(--gold); }

@media (max-width: 900px) {
  a.ref-card { padding: 18px 18px; gap: 14px; }
}

/* ─── 本文内の小見出し ─── */
.take h3.sub {
  font-size: 1.1rem; font-weight: 700; line-height: 1.5; color: var(--ink-blue);
  margin: 2.8em 0 1.2em; padding-top: 1.6em;
  border-top: 1px solid var(--border-soft);
}

/* ─── 本文内の箇条書き ─── */
.take ul.bullets { list-style: none; margin: 1.8em 0; }
.take ul.bullets li {
  position: relative; padding-left: 20px; margin-bottom: 0.9em;
  font-size: 0.93rem; line-height: 2.0; color: var(--text-body);
}
.take ul.bullets li:last-child { margin-bottom: 0; }
.take ul.bullets li::before {
  content: ''; position: absolute; left: 2px; top: 0.85em;
  width: 5px; height: 5px; border-radius: 50%; background: var(--gold);
}

/* ─── CTA内のビジュアル（研QのOGP）─── */
.cta-visual { display: block; border-radius: 4px; overflow: hidden; line-height: 0; }
.cta-visual img { width: 100%; height: auto; display: block; transition: opacity 0.2s; }
.cta-visual:hover img { opacity: 0.88; }
.cta-body .cta-sub { margin-bottom: 14px; }