/* ===========================
   なるすろ — 記事プラットフォーム
   note風の読みやすさを重視
   =========================== */

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; }

:root {
  --bg: #fafaf7;
  --bg-card: #ffffff;
  --bg-paper: #ffffff;
  --bg-dark: #1a1a1a;
  --text: #1a1a1a;
  --text-muted: #5a5a5a;
  --text-dim: #999999;
  --border: #e8e6df;
  --border-strong: #d4d1c8;
  --accent: #e08a3a;
  --accent-soft: #f0b380;
  --accent-bg: #fdf4eb;
  --paywall-bg: linear-gradient(180deg, rgba(255,255,255,0) 0%, rgba(255,255,255,1) 70%);
  --sans: 'Noto Sans JP', sans-serif;
  --serif: 'Noto Serif JP', 'Yu Mincho', 'Hiragino Mincho ProN', serif;
  --max-w: 1200px;
  --max-w-narrow: 720px;
  --pad: clamp(16px, 4vw, 32px);
}

body {
  font-family: var(--sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.85;
  letter-spacing: 0.02em;
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; transition: color .2s ease; }
ul { list-style: none; }
button { background: none; border: none; cursor: pointer; color: inherit; font: inherit; }

/* ===========================
   ヘッダー（プラットフォーム共通）
   =========================== */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(250, 250, 247, 0.96);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.site-header__inner {
  max-width: var(--max-w); margin: 0 auto;
  padding: 16px var(--pad);
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
}
.site-logo {
  display: inline-flex; align-items: baseline; gap: 8px;
  font-family: var(--serif); font-weight: 600;
  color: var(--text);
}
.site-logo__mark {
  font-size: 22px; letter-spacing: 0.04em;
}
.site-logo__sub {
  font-family: var(--sans); font-size: 11px; font-weight: 500;
  color: var(--text-muted); letter-spacing: 0.15em;
}
.site-nav { display: flex; align-items: center; gap: 24px; }
.site-nav a {
  font-family: var(--sans); font-size: 13px; font-weight: 500;
  color: var(--text-muted);
}
.site-nav a:hover { color: var(--accent); }
.site-nav a.is-active { color: var(--text); }
.site-nav__back {
  display: inline-flex; align-items: center; gap: 6px;
  font-size: 12px; letter-spacing: 0.05em;
}
.site-nav__back::before { content: '←'; }

/* ===========================
   トップ（記事一覧ページ）
   =========================== */
.platform-hero {
  padding: clamp(40px, 8vw, 80px) 0 clamp(32px, 6vw, 56px);
  border-bottom: 1px solid var(--border);
}
.platform-hero__inner {
  max-width: var(--max-w); margin: 0 auto; padding: 0 var(--pad);
}
.platform-hero__eyebrow {
  font-family: var(--sans); font-size: 11px; font-weight: 700;
  letter-spacing: 0.3em; color: var(--accent); margin-bottom: 16px;
  text-transform: uppercase;
}
.platform-hero__title {
  font-family: var(--serif); font-weight: 600;
  font-size: clamp(28px, 4.5vw, 44px); line-height: 1.45; letter-spacing: 0.04em;
  color: var(--text); margin-bottom: 20px;
}
.platform-hero__title em {
  font-style: normal; color: var(--accent);
}
.platform-hero__lead {
  font-family: var(--sans); font-size: clamp(14px, 1.4vw, 16px);
  color: var(--text-muted); max-width: 640px; line-height: 1.95;
}

/* カテゴリタブ */
.category-tabs {
  max-width: var(--max-w); margin: 0 auto;
  padding: 24px var(--pad);
  display: flex; gap: 8px; overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}
.category-tabs::-webkit-scrollbar { display: none; }
.category-tab {
  padding: 8px 18px;
  font-family: var(--sans); font-size: 13px; font-weight: 500;
  color: var(--text-muted); white-space: nowrap;
  border: 1px solid var(--border);
  background: var(--bg-card);
  transition: all .2s ease;
  border-radius: 100px;
}
.category-tab:hover { color: var(--text); border-color: var(--border-strong); }
.category-tab.is-active {
  background: var(--text); color: var(--bg); border-color: var(--text);
}

/* 記事グリッド */
.article-list {
  max-width: var(--max-w); margin: 0 auto;
  padding: clamp(32px, 5vw, 48px) var(--pad);
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px;
}

.article-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  display: flex; flex-direction: column;
  transition: all .3s ease;
  position: relative;
}
.article-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent-soft);
  box-shadow: 0 14px 40px rgba(26, 26, 26, 0.08);
}
.article-card__thumb {
  width: 100%; aspect-ratio: 16/9;
  background: linear-gradient(135deg, #f5f0e6 0%, #e8e0cf 100%);
  display: flex; align-items: center; justify-content: center;
  color: var(--text-muted); font-family: var(--serif); font-size: 14px;
  letter-spacing: 0.15em; border-bottom: 1px solid var(--border);
  position: relative; overflow: hidden;
}
.article-card__thumb-mark {
  font-family: var(--serif); font-weight: 600; font-size: 48px;
  color: rgba(26, 26, 26, 0.15); letter-spacing: 0.05em;
}
.article-card__body { padding: 24px 22px 22px; display: flex; flex-direction: column; flex: 1; }
.article-card__category {
  display: inline-block; padding: 3px 10px;
  background: var(--accent-bg); color: var(--accent);
  font-family: var(--sans); font-size: 10px; font-weight: 700;
  letter-spacing: 0.15em; margin-bottom: 12px;
  align-self: flex-start;
}
.article-card__title {
  font-family: var(--serif); font-weight: 600;
  font-size: 17px; line-height: 1.55; letter-spacing: 0.03em;
  color: var(--text); margin-bottom: 12px;
  display: -webkit-box; -webkit-line-clamp: 3; -webkit-box-orient: vertical;
  overflow: hidden;
}
.article-card__excerpt {
  font-family: var(--sans); font-size: 13px; line-height: 1.85;
  color: var(--text-muted); margin-bottom: 16px; flex: 1;
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical;
  overflow: hidden;
}
.article-card__meta {
  display: flex; justify-content: space-between; align-items: center;
  padding-top: 14px; border-top: 1px solid var(--border);
  font-family: var(--sans); font-size: 11px;
}
.article-card__date {
  color: var(--text-dim); font-feature-settings: "tnum"; letter-spacing: 0.05em;
}
.article-card__price {
  font-family: var(--serif); font-weight: 700;
  color: var(--accent); font-size: 14px; font-feature-settings: "tnum";
}
.article-card__price--free {
  color: var(--text-muted); font-size: 11px; font-weight: 500;
  letter-spacing: 0.15em; font-family: var(--sans);
}

/* ===========================
   記事詳細ページ
   =========================== */
.article {
  max-width: var(--max-w-narrow); margin: 0 auto;
  padding: clamp(32px, 5vw, 64px) var(--pad) clamp(40px, 6vw, 80px);
}
.article__crumb {
  font-family: var(--sans); font-size: 11px; letter-spacing: 0.12em;
  color: var(--text-muted); margin-bottom: 24px;
}
.article__crumb a:hover { color: var(--accent); }
.article__crumb-sep { margin: 0 8px; color: var(--text-dim); }
.article__category {
  display: inline-block; padding: 4px 12px;
  background: var(--accent-bg); color: var(--accent);
  font-family: var(--sans); font-size: 11px; font-weight: 700;
  letter-spacing: 0.2em; margin-bottom: 20px;
}
.article__title {
  font-family: var(--serif); font-weight: 700;
  font-size: clamp(24px, 4vw, 36px); line-height: 1.5; letter-spacing: 0.04em;
  color: var(--text); margin-bottom: 24px;
}
.article__meta {
  display: flex; align-items: center; gap: 16px;
  padding-bottom: 32px; margin-bottom: 40px;
  border-bottom: 1px solid var(--border);
  font-family: var(--sans); font-size: 12px;
  color: var(--text-muted); letter-spacing: 0.05em;
}
.article__meta-divider { color: var(--text-dim); }
.article__date { font-feature-settings: "tnum"; }

/* 本文（無料部分） */
.article__body {
  font-family: var(--sans); font-size: 16px; line-height: 2;
  color: var(--text); letter-spacing: 0.04em;
}
.article__body h2 {
  font-family: var(--serif); font-weight: 600;
  font-size: clamp(20px, 2.4vw, 24px); line-height: 1.6;
  margin: 56px 0 20px; padding-bottom: 12px;
  border-bottom: 2px solid var(--text);
  letter-spacing: 0.04em;
}
.article__body h3 {
  font-family: var(--sans); font-weight: 700;
  font-size: 17px; line-height: 1.6;
  margin: 36px 0 14px;
  padding-left: 12px; border-left: 3px solid var(--accent);
  letter-spacing: 0.04em;
}
.article__body p { margin-bottom: 20px; }
.article__body strong { font-weight: 700; }
.article__body em {
  font-style: normal; background: linear-gradient(transparent 60%, var(--accent-bg) 60%);
  padding: 0 2px;
}
.article__body ul, .article__body ol {
  margin: 0 0 24px 24px;
}
.article__body ul li { list-style: disc; margin-bottom: 8px; }
.article__body ol li { list-style: decimal; margin-bottom: 8px; }
.article__body blockquote {
  margin: 24px 0; padding: 16px 20px;
  background: var(--bg-card); border-left: 3px solid var(--accent);
  font-size: 14px; color: var(--text-muted);
}
.article__body table {
  width: 100%; border-collapse: collapse; margin: 24px 0;
  font-size: 14px;
}
.article__body th, .article__body td {
  padding: 10px 14px; border-bottom: 1px solid var(--border);
  text-align: left;
}
.article__body th { background: var(--bg-card); font-weight: 700; }
.article__body code {
  background: var(--bg-card); padding: 2px 6px;
  font-family: 'SF Mono', Monaco, monospace; font-size: 0.9em;
  border: 1px solid var(--border);
}

/* 有料領域のフェードアウト */
.article__paywall-fade {
  position: relative;
  max-height: 220px; overflow: hidden;
  margin-top: -8px;
}
.article__paywall-fade::after {
  content: ''; position: absolute; left: 0; right: 0; bottom: 0; height: 180px;
  background: var(--paywall-bg);
  pointer-events: none;
}

/* Paywall ボックス */
.paywall {
  margin: 32px 0;
  padding: 36px 32px;
  background: var(--bg-card);
  border: 2px solid var(--accent);
  text-align: center;
  position: relative;
}
.paywall__tag {
  display: inline-block; padding: 5px 14px;
  background: var(--accent); color: #fff;
  font-family: var(--sans); font-size: 10px; font-weight: 700;
  letter-spacing: 0.3em; margin-bottom: 18px;
}
.paywall__title {
  font-family: var(--serif); font-weight: 600;
  font-size: 22px; line-height: 1.5; letter-spacing: 0.04em;
  margin-bottom: 16px;
}
.paywall__text {
  font-family: var(--sans); font-size: 13px; line-height: 1.95;
  color: var(--text-muted); margin-bottom: 24px;
}
.paywall__price {
  font-family: var(--serif); font-weight: 700;
  font-size: 36px; color: var(--text); margin-bottom: 24px;
  font-feature-settings: "tnum";
}
.paywall__price small {
  font-family: var(--sans); font-size: 13px; font-weight: 500;
  color: var(--text-muted); letter-spacing: 0.05em; margin-left: 6px;
}
.paywall__cta {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 16px 40px; min-height: 52px;
  font-family: var(--sans); font-size: 14px; font-weight: 700;
  letter-spacing: 0.15em;
  background: var(--accent); color: #ffffff;
  border: 2px solid var(--accent);
  transition: all .2s ease;
}
.paywall__cta:hover { background: var(--text); border-color: var(--text); }
.paywall__cta::after { content: '→'; font-family: var(--serif); }
.paywall__note {
  margin-top: 16px; font-size: 11px; color: var(--text-dim);
  letter-spacing: 0.05em;
}

/* 購入済みバナー（記事ロック解除後に表示）*/
.purchased-banner {
  display: flex; align-items: center; justify-content: center;
  padding: 14px 20px; margin-bottom: 32px;
  background: #f0f9ed; color: #2a7a3a;
  border: 1px solid #c0e0b8;
  font-family: var(--sans); font-size: 13px; font-weight: 700;
  letter-spacing: 0.08em;
}

/* 記事末の関連記事 */
.article-related {
  max-width: var(--max-w-narrow); margin: 0 auto;
  padding: 0 var(--pad) clamp(40px, 6vw, 80px);
}
.article-related__title {
  font-family: var(--sans); font-size: 13px; font-weight: 700;
  letter-spacing: 0.2em; color: var(--text-muted);
  margin-bottom: 20px; padding-bottom: 12px;
  border-bottom: 1px solid var(--border);
}
.article-related__list {
  display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px;
}

/* ===========================
   フッター
   =========================== */
.site-footer {
  background: var(--text); color: var(--bg);
  padding: 40px var(--pad) 24px;
  border-top: 4px solid var(--accent);
  margin-top: 60px;
}
.site-footer__inner {
  max-width: var(--max-w); margin: 0 auto;
  display: flex; justify-content: space-between; align-items: center;
  gap: 16px; flex-wrap: wrap;
}
.site-footer__brand {
  font-family: var(--serif); font-weight: 600; font-size: 18px;
  letter-spacing: 0.04em;
}
.site-footer__links {
  display: flex; gap: 24px; font-family: var(--sans); font-size: 12px;
  letter-spacing: 0.08em;
}
.site-footer__links a { color: rgba(255,255,255,0.75); }
.site-footer__links a:hover { color: var(--accent-soft); }
.site-footer__copy {
  font-family: var(--sans); font-size: 11px;
  color: rgba(255,255,255,0.5); letter-spacing: 0.1em;
  margin-top: 20px; padding-top: 16px;
  border-top: 1px solid rgba(255,255,255,0.1);
  text-align: center;
}

/* ===========================
   レスポンシブ
   =========================== */
@media (max-width: 880px) {
  .article-list { grid-template-columns: repeat(2, 1fr); gap: 20px; }
}
@media (max-width: 600px) {
  .article-list { grid-template-columns: 1fr; gap: 16px; }
  .article-related__list { grid-template-columns: 1fr; }
  .article__body { font-size: 15px; }
  .article__title { font-size: clamp(22px, 5.5vw, 28px); }
  .paywall { padding: 28px 22px; }
  .paywall__price { font-size: 30px; }
  .site-nav { gap: 14px; }
  .site-nav a { font-size: 12px; }
}