:root {
  --gptc-bg: #f6f8fb;
  --gptc-surface: #ffffff;
  --gptc-surface-soft: #f9fafb;
  --gptc-text: #0f172a;
  --gptc-muted: #64748b;
  --gptc-border: #e5e7eb;
  --gptc-brand: #10a37f;
  --gptc-brand-dark: #0b7f63;
  --gptc-brand-soft: #e8f8f3;
  --gptc-warning: #f59e0b;
  --gptc-warning-bg: #fff7ed;
  --gptc-warning-border: #fed7aa;
  --gptc-radius-sm: 8px;
  --gptc-radius-md: 12px;
  --gptc-radius-lg: 16px;
  --gptc-shadow-card: 0 10px 30px rgba(15, 23, 42, .08);
  --gptc-shadow-soft: 0 6px 18px rgba(15, 23, 42, .06);
  --gptc-container: 1120px;
  --gptc-article: 760px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--gptc-bg);
  color: var(--gptc-text);
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Arial, sans-serif;
  line-height: 1.7;
  -webkit-text-size-adjust: 100%;
}
a { color: var(--gptc-brand-dark); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 3px; }
button, input { font: inherit; }

.gptc-container,
.article-container,
.footer-inner,
.site-nav {
  width: min(100% - 32px, var(--gptc-container));
  margin-inline: auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 30;
  background: rgba(246, 248, 251, .94);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(229, 231, 235, .9);
}
.site-nav {
  min-height: 66px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}
.site-brand {
  color: var(--gptc-text);
  font-size: 21px;
  font-weight: 900;
  white-space: nowrap;
}
.site-links {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 14px;
}
.site-links a,
.site-links button {
  color: #334155;
  border: 0;
  background: transparent;
  padding: 0;
  font-size: 14px;
  font-weight: 750;
  cursor: pointer;
  white-space: nowrap;
}
.site-links .nav-buy {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 40px;
  padding: 0 14px;
  border-radius: var(--gptc-radius-sm);
  background: var(--gptc-brand);
  color: #fff;
  box-shadow: 0 10px 24px rgba(16, 163, 127, .26);
}

.article-hero {
  background: linear-gradient(180deg, #fff 0%, #f6f8fb 100%);
  border-bottom: 1px solid var(--gptc-border);
  padding: 56px 0 42px;
}
.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.45fr) minmax(280px, .75fr);
  gap: 36px;
  align-items: start;
}
.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
  color: var(--gptc-muted);
  font-size: 14px;
  margin-bottom: 18px;
}
.breadcrumbs a { color: #475569; font-weight: 700; }
.article-kicker,
.gptc-pill,
.card-kicker {
  display: inline-flex;
  align-items: center;
  width: fit-content;
  min-height: 30px;
  border-radius: 999px;
  padding: 0 12px;
  background: var(--gptc-brand-soft);
  color: var(--gptc-brand-dark);
  font-size: 13px;
  font-weight: 800;
}
h1 {
  max-width: 860px;
  margin: 18px 0 16px;
  color: var(--gptc-text);
  font-size: clamp(34px, 5vw, 56px);
  line-height: 1.08;
  letter-spacing: 0;
  font-weight: 850;
}
.article-dek {
  max-width: 780px;
  margin: 0;
  color: #475569;
  font-size: 18px;
  line-height: 1.8;
}
.article-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 9px;
  margin-top: 18px;
  color: var(--gptc-muted);
  font-size: 14px;
}

.article-shell { padding: 48px 0 76px; }
.article-grid {
  display: grid;
  grid-template-columns: minmax(0, var(--gptc-article)) 310px;
  gap: 36px;
  align-items: start;
}
.article-main { min-width: 0; }
.article-main h2 {
  margin: 42px 0 14px;
  color: var(--gptc-text);
  font-size: 28px;
  line-height: 1.25;
  letter-spacing: 0;
  font-weight: 800;
}
.article-main h3 {
  margin: 28px 0 10px;
  color: var(--gptc-text);
  font-size: 21px;
  line-height: 1.35;
  font-weight: 780;
}
.article-main p,
.article-main li {
  color: #475569;
  font-size: 17px;
  line-height: 1.85;
}
.article-main p { margin: 12px 0; }
.article-main ul,
.article-main ol { padding-left: 22px; margin: 12px 0; }
.article-main li { margin: 8px 0; }
.article-main strong { color: var(--gptc-text); }
.article-main code {
  border-radius: 6px;
  padding: 2px 6px;
  background: var(--gptc-brand-soft);
  color: var(--gptc-brand-dark);
}
.article-main pre {
  white-space: pre-wrap;
  overflow: auto;
  border-radius: var(--gptc-radius-sm);
  background: #0f172a;
  color: #e2e8f0;
  padding: 16px;
}
.article-main table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  border: 1px solid var(--gptc-border);
  border-radius: var(--gptc-radius-sm);
  overflow: hidden;
  background: #fff;
  margin: 18px 0;
}
.article-main th,
.article-main td {
  padding: 14px 16px;
  border-bottom: 1px solid var(--gptc-border);
  text-align: left;
  vertical-align: top;
  font-size: 16px;
  line-height: 1.65;
}
.article-main th { background: #f8fafc; color: var(--gptc-text); font-weight: 780; }
.article-main tr:last-child td { border-bottom: 0; }
.article-aside {
  position: sticky;
  top: 88px;
  display: grid;
  gap: 16px;
}

.gptc-card,
.card,
.purchase-card,
.diagnosis-card,
.notice-card,
.notice,
.note,
.answer-box,
.note-box,
.box,
.toc,
.related-box,
.faq-box,
.next-step-card,
.rel,
.tag-card,
.post-card {
  border: 1px solid var(--gptc-border);
  border-radius: var(--gptc-radius-sm);
  background: var(--gptc-surface);
  box-shadow: var(--gptc-shadow-soft);
}
.purchase-card {
  padding: 22px;
  border-color: rgba(16, 163, 127, .2);
  background:
    radial-gradient(circle at top right, rgba(16, 163, 127, .11), transparent 36%),
    #fff;
}
.purchase-card.compact { padding: 20px; }
.purchase-card.inline-card { margin: 28px 0; }
.purchase-card h2,
.purchase-card h3 {
  margin: 0 0 10px;
  color: var(--gptc-text);
  font-size: 22px;
  line-height: 1.28;
  font-weight: 850;
}
.purchase-card .price {
  margin: 0 0 8px;
  color: var(--gptc-brand-dark);
  font-size: 32px;
  line-height: 1.1;
  font-weight: 900;
}
.purchase-card p {
  color: #475569;
  font-size: 15px;
  line-height: 1.72;
}
.purchase-card ul {
  display: grid;
  gap: 8px;
  padding: 0;
  margin: 14px 0;
  list-style: none;
}
.purchase-card li {
  color: #475569;
  font-size: 15px;
  line-height: 1.55;
}
.purchase-card li::before {
  content: "";
  display: inline-block;
  width: 7px;
  height: 7px;
  margin-right: 8px;
  border-radius: 999px;
  background: var(--gptc-brand);
  transform: translateY(-1px);
}
.card-note,
.purchase-card .card-note {
  margin-top: 12px;
  color: var(--gptc-muted);
  font-size: 13px;
  line-height: 1.6;
}

.button-row,
.cta-actions,
.gptc-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
  margin-top: 14px;
}
.button,
.btn,
.cta-button,
.home,
.nav-cta,
.gptc-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
  border-radius: var(--gptc-radius-sm);
  border: 1px solid transparent;
  font-weight: 850;
  font-size: 15px;
  cursor: pointer;
  text-decoration: none;
  transition: transform .15s ease, box-shadow .15s ease, background .15s ease;
}
.button:hover,
.btn:hover,
.cta-button:hover,
.gptc-btn:hover {
  transform: translateY(-1px);
  text-decoration: none;
}
.button-primary,
.btn.primary,
.cta-button,
.home,
.nav-cta,
.gptc-btn-primary {
  background: var(--gptc-brand);
  color: #fff !important;
  box-shadow: 0 10px 24px rgba(16, 163, 127, .28);
}
.button-primary:hover,
.gptc-btn-primary:hover { background: var(--gptc-brand-dark); }
.button-secondary,
.btn.secondary,
.gptc-btn-secondary {
  background: #fff;
  color: var(--gptc-text) !important;
  border-color: var(--gptc-border);
}
.button-ghost,
.btn.ghost,
.gptc-btn-ghost {
  background: var(--gptc-brand-soft);
  color: var(--gptc-brand-dark) !important;
  border-color: rgba(16, 163, 127, .18);
}

.diagnosis-card { padding: 20px; margin: 0 0 30px; }
.diagnosis-card strong { display: block; margin-bottom: 12px; font-size: 20px; }
.diagnosis-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}
.diagnosis-grid a,
.diagnosis-grid .diagnosis-item {
  display: block;
  width: 100%;
  text-align: left;
  border: 1px solid var(--gptc-border);
  border-radius: var(--gptc-radius-sm);
  padding: 14px;
  background: #f8fafc;
  text-decoration: none;
}
.diagnosis-grid b {
  display: block;
  color: var(--gptc-text);
  font-size: 15px;
  margin-bottom: 4px;
}
.diagnosis-grid span {
  color: var(--gptc-brand-dark);
  font-size: 13px;
  font-weight: 850;
}
.diagnosis-grid p {
  margin: 4px 0 0;
  font-size: 14px;
  line-height: 1.55;
}
.notice-card,
.box.warn,
.note-box {
  background: var(--gptc-warning-bg);
  border-color: var(--gptc-warning-border);
  color: #9a3412;
  padding: 18px 20px;
  margin: 22px 0;
}
.notice-card p,
.notice-card li,
.box.warn p,
.box.warn li,
.note-box p,
.note-box li { color: #7c2d12; }
.notice,
.note,
.box:not(.warn),
.answer-box {
  padding: 18px 20px;
  margin: 22px 0;
  background: #fff;
}
.answer-box {
  border-color: rgba(16, 163, 127, .25);
  background: linear-gradient(180deg, #f8fffc, #fff);
}
.answer-box strong,
.note-box strong,
.related-box strong,
.faq-box strong { display: block; margin-bottom: 8px; font-size: 18px; }
.toc { padding: 16px; box-shadow: none; }
.toc strong { display: block; margin-bottom: 8px; color: var(--gptc-text); }
.toc a {
  display: block;
  padding: 7px 0;
  color: #475569;
  font-size: 14px;
  line-height: 1.45;
  text-decoration: none;
}
.faq-box,
.related-box,
.rel { padding: 20px; margin: 28px 0; }
.faq-box details { border-top: 1px solid var(--gptc-border); padding: 13px 0; }
.faq-box details:first-of-type { border-top: 0; }
.faq-box summary { cursor: pointer; color: var(--gptc-text); font-weight: 850; }
.related-grid,
.rel { display: grid; gap: 10px; }
.related-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.rel a,
.related-grid a {
  display: block;
  border: 1px solid var(--gptc-border);
  border-radius: var(--gptc-radius-sm);
  padding: 12px 14px;
  background: #f8fafc;
  color: var(--gptc-text);
  font-weight: 760;
  text-decoration: none;
}
.next-step-card {
  margin: 36px 0 0;
  padding: 24px;
  background: var(--gptc-text);
  color: #fff;
  border-color: var(--gptc-text);
}
.next-step-card h2 { color: #fff; margin-top: 0; }
.next-step-card p,
.next-step-card li { color: #cbd5e1; }
.next-step-list {
  display: grid;
  gap: 10px;
  margin: 16px 0 0;
}
.next-step-list div {
  border: 1px solid rgba(255,255,255,.12);
  border-radius: var(--gptc-radius-sm);
  padding: 12px;
  background: rgba(255,255,255,.04);
}
.next-step-list b { color: #fff; display: block; margin-bottom: 3px; }

.site-footer {
  border-top: 1px solid var(--gptc-border);
  background: #fff;
  color: var(--gptc-muted);
  padding: 28px 24px 96px;
  font-size: 14px;
}
.site-footer a { color: #475569; font-weight: 760; }

.mobile-sticky {
  position: fixed;
  left: 12px;
  right: 12px;
  bottom: 12px;
  z-index: 40;
  display: none;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  padding: 10px;
  border: 1px solid rgba(229, 231, 235, .92);
  border-radius: var(--gptc-radius-sm);
  background: rgba(255,255,255,.96);
  box-shadow: 0 18px 44px rgba(15,23,42,.16);
  backdrop-filter: blur(14px);
}
.mobile-sticky a { min-height: 42px; font-size: 14px; }
.toast {
  position: fixed;
  left: 50%;
  bottom: 84px;
  z-index: 60;
  transform: translateX(-50%);
  border-radius: var(--gptc-radius-sm);
  background: var(--gptc-text);
  color: #fff;
  padding: 10px 14px;
  box-shadow: 0 12px 30px rgba(15,23,42,.24);
  opacity: 0;
  pointer-events: none;
  transition: opacity .18s ease, transform .18s ease;
}
.toast.show { opacity: 1; transform: translate(-50%, -6px); }

.tag-page,
.buy-page {
  min-height: 100vh;
}
.tag-hero,
.buy-hero {
  padding: 56px 0 32px;
}
.tag-hero h1,
.buy-hero h1 {
  margin: 14px 0 12px;
}
.tag-grid,
.post-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin: 22px 0 42px;
}
.tag-card,
.post-card {
  display: block;
  padding: 18px;
  color: var(--gptc-text);
}
.tag-card strong,
.post-card strong {
  display: block;
  color: var(--gptc-text);
  font-size: 19px;
  line-height: 1.35;
  margin-bottom: 6px;
}
.tag-card p,
.post-card p {
  color: #475569;
  margin: 0;
}
.buy-panel {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 320px;
  gap: 18px;
  align-items: start;
}
.buy-checklist {
  display: grid;
  gap: 10px;
  margin: 18px 0 0;
  padding: 0;
  list-style: none;
}
.buy-checklist li {
  border: 1px solid var(--gptc-border);
  border-radius: var(--gptc-radius-sm);
  background: #fff;
  padding: 12px 14px;
  color: #334155;
}

@media (max-width: 980px) {
  .site-links a:not(.nav-buy),
  .site-links button { display: none; }
  .hero-grid,
  .article-grid,
  .buy-panel { grid-template-columns: 1fr; }
  .article-aside { position: static; }
  .article-aside .purchase-card { display: none; }
  .article-hero { padding-top: 42px; }
  .diagnosis-grid,
  .tag-grid,
  .post-grid { grid-template-columns: 1fr; }
}
@media (max-width: 680px) {
  .gptc-container,
  .article-container,
  .footer-inner,
  .site-nav { width: min(100% - 28px, var(--gptc-container)); }
  .site-nav { min-height: 58px; }
  .site-brand { font-size: 19px; }
  .article-hero { padding: 34px 0 28px; }
  h1 { font-size: clamp(32px, 10vw, 42px); }
  .article-dek { font-size: 17px; }
  .article-shell { padding: 34px 0 58px; }
  .purchase-card.compact { display: none; }
  .button-row,
  .cta-actions,
  .gptc-actions { display: grid; grid-template-columns: 1fr; }
  .button,
  .btn,
  .cta-button,
  .gptc-btn { width: 100%; }
  .related-grid { grid-template-columns: 1fr; }
  .mobile-sticky { display: grid; }
  .site-footer { padding-bottom: 110px; }
}