/* Hallmark · macrostructure: technical explainer · genre: specialist editorial · contrast: pass (40–41) · mobile: pass (34, 49–57) */
/* Hallmark · pre-emit critique: P5 H5 E4 S5 R4 V4 */
.solar-payback-page {
  --payback-navy: #14334b;
  --payback-navy-strong: #0d2a40;
  --payback-blue: #156082;
  --payback-blue-dark: #0f4b68;
  --payback-blue-soft: #eef6fa;
  --payback-blue-faint: #f6fafc;
  --payback-paper: #ffffff;
  --payback-canvas: #f7f9fa;
  --payback-text: #273844;
  --payback-muted: #5a6a75;
  --payback-line: #ccdbe4;
  --payback-line-light: #e1e9ee;
  background: var(--payback-canvas);
  color: var(--payback-text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans JP", sans-serif;
  line-height: 1.85;
}

.solar-payback-page * { box-sizing: border-box; }
.solar-payback-page a { text-underline-offset: 0.18em; }
.solar-payback-page a:focus-visible,
.solar-payback-page summary:focus-visible { outline: 3px solid var(--payback-blue); outline-offset: 3px; }

.payback-container { max-width: 1160px; margin-inline: auto; padding: 28px 24px 88px; }
.payback-breadcrumb { display: flex; flex-wrap: wrap; gap: 7px; align-items: center; margin-bottom: 30px; color: var(--payback-muted); font-size: 0.875rem; }
.payback-breadcrumb a { color: var(--payback-blue-dark); }

.payback-hero { max-width: 920px; padding: 50px 0 44px; }
.payback-label { margin: 0 0 16px; color: var(--payback-blue-dark); font-size: 0.875rem; font-weight: 700; letter-spacing: 0.06em; }
.payback-hero h1 { max-width: 900px; margin: 0; color: var(--payback-navy); font-size: clamp(2.25rem, 5vw, 4.25rem); line-height: 1.18; letter-spacing: -0.035em; overflow-wrap: anywhere; }
.payback-lead { max-width: 760px; margin: 28px 0 0; color: var(--payback-text); font-size: clamp(1rem, 1.5vw, 1.125rem); line-height: 1.9; }
.article-meta { display: flex; flex-wrap: wrap; gap: 10px 24px; margin: 28px 0 0; color: var(--payback-muted); font-size: 0.875rem; }
.article-meta div { display: flex; gap: 0.45em; }
.article-meta dt { font-weight: 700; color: var(--payback-navy); }
.article-meta dd { margin: 0; }
.article-meta a { color: var(--payback-blue-dark); }

.direct-answer { margin: 0 0 72px; padding: 30px 34px; border: 1px solid var(--payback-line); border-left: 4px solid var(--payback-blue); background: var(--payback-blue-soft); }
.direct-answer h2 { margin: 0 0 14px; color: var(--payback-navy); font-size: clamp(1.35rem, 2.5vw, 1.85rem); line-height: 1.45; }
.direct-answer p { max-width: 900px; margin: 0; }

.reading-column { max-width: 780px; margin-inline: auto; }
.payback-section { margin: 0 0 76px; }
.payback-section h2,
.wide-section h2 { margin: 0 0 22px; color: var(--payback-navy); font-size: clamp(1.7rem, 3.2vw, 2.35rem); line-height: 1.42; letter-spacing: -0.02em; }
.payback-section h3 { margin: 0 0 10px; color: var(--payback-navy); font-size: 1.12rem; line-height: 1.5; }
.payback-section p { margin: 0 0 20px; }
.payback-section ul { padding-left: 1.35em; }
.payback-section li + li { margin-top: 7px; }

.formula-list { margin: 28px 0; border: 1px solid var(--payback-line); background: var(--payback-paper); }
.formula-list p { display: grid; grid-template-columns: minmax(150px, 0.75fr) minmax(0, 1.5fr); gap: 18px; align-items: center; margin: 0; padding: 17px 20px; border-bottom: 1px solid var(--payback-line-light); }
.formula-list p:last-child { border-bottom: 0; }
.formula-list span { color: var(--payback-blue-dark); font-weight: 700; }
.formula-list strong { color: var(--payback-navy); font-size: 1.03rem; }
.formula-list .formula-result { background: var(--payback-blue-soft); }
.payback-note { margin-top: 26px; padding: 22px 24px; border-left: 4px solid var(--payback-blue); background: var(--payback-blue-faint); }
.payback-note p { margin: 0; }

.wide-section { margin: 0 0 82px; padding: 40px 34px; border-top: 1px solid var(--payback-line); border-bottom: 1px solid var(--payback-line); background: var(--payback-paper); }
.section-heading-copy { max-width: 780px; margin: 0 auto 28px; }
.section-heading-copy p { margin: 0; }
.responsive-table table { width: 100%; border-collapse: collapse; table-layout: fixed; background: var(--payback-paper); }
.responsive-table th,
.responsive-table td { padding: 15px 16px; border: 1px solid var(--payback-line); text-align: left; vertical-align: top; overflow-wrap: anywhere; }
.responsive-table thead th { background: var(--payback-blue-soft); color: var(--payback-navy); font-size: 0.9rem; font-weight: 700; }
.responsive-table tbody th { width: 20%; color: var(--payback-blue-dark); font-weight: 700; }
.responsive-table tbody td { color: var(--payback-text); font-size: 0.96rem; }
.responsive-table tbody tr:hover { background: var(--payback-blue-faint); }

.calculation-steps { margin: 28px 0 18px; padding: 0; list-style: none; counter-reset: step; border-top: 1px solid var(--payback-line); }
.calculation-steps li { display: grid; grid-template-columns: 190px minmax(0, 1fr); gap: 20px; margin: 0; padding: 18px 0; border-bottom: 1px solid var(--payback-line); counter-increment: step; }
.calculation-steps strong::before { content: counter(step) ". "; color: var(--payback-blue); }
.calculation-steps span { overflow-wrap: anywhere; }
.source-caption { color: var(--payback-muted); font-size: 0.875rem; }

.simulator-callout { margin: 0 0 76px; padding: 28px 30px; border: 1px solid var(--payback-line); background: var(--payback-blue-soft); }
.simulator-callout h2 { margin: 0 0 10px; color: var(--payback-navy); font-size: 1.6rem; line-height: 1.45; }
.simulator-callout p { margin: 0 0 18px; }
.simulator-callout a,
.section-link { display: flex; min-height: 48px; align-items: center; justify-content: space-between; gap: 16px; width: 100%; padding: 11px 17px; border: 1px solid var(--payback-blue); background: var(--payback-paper); color: var(--payback-blue-dark); font-weight: 700; text-decoration: none; transition: background-color 160ms ease, border-color 160ms ease; }
.simulator-callout a:hover,
.section-link:hover { border-color: var(--payback-blue-dark); background: var(--payback-blue-faint); }
.simulator-callout a:active,
.section-link:active { background: var(--payback-blue-soft); }

.tendency-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 28px; margin-top: 28px; }
.tendency-grid section { padding-top: 18px; border-top: 3px solid var(--payback-blue); }
.tendency-grid section:last-child { border-top-color: var(--payback-navy); }
.tendency-grid ul { margin-bottom: 0; }
.comparison-table { margin: 26px 0 20px; }
@media (min-width: 769px) {
  .solar-payback-page .comparison-table tbody th { color: var(--payback-paper); }
}
.check-list { columns: 2; column-gap: 38px; margin: 26px 0 0; }
.check-list li { break-inside: avoid; padding-right: 10px; }

.sources { padding: 26px 28px; border-left: 4px solid var(--payback-blue); background: var(--payback-blue-faint); }
.sources ul { margin-bottom: 20px; }
.sources p:last-child { margin-bottom: 0; }

.related-links { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; }
.related-links a { display: flex; min-height: 88px; flex-direction: column; justify-content: center; padding: 16px 18px; border: 1px solid var(--payback-line); background: var(--payback-paper); color: var(--payback-navy); text-decoration: none; transition: background-color 160ms ease, border-color 160ms ease; }
.related-links a::after { content: "→"; align-self: flex-end; margin-top: -1.35em; color: var(--payback-blue); font-weight: 700; }
.related-links a:hover { border-color: var(--payback-blue); background: var(--payback-blue-faint); }
.related-links a:active { background: var(--payback-blue-soft); }
.related-links strong { padding-right: 24px; font-size: 1rem; }
.related-links span { margin-top: 4px; padding-right: 24px; color: var(--payback-muted); font-size: 0.86rem; }

.faq-section details { border-top: 1px solid var(--payback-line); }
.faq-section details:last-child { border-bottom: 1px solid var(--payback-line); }
.faq-section summary { min-height: 56px; padding: 15px 36px 15px 2px; color: var(--payback-navy); font-weight: 700; cursor: pointer; }
.faq-section details p { padding: 0 2px 20px; margin: 0; }

.final-cta { margin-top: 88px; padding: 46px 42px; background: var(--payback-navy); color: var(--payback-paper); text-align: center; }
.final-cta h2 { margin: 0 0 14px; color: var(--payback-paper); font-size: clamp(1.7rem, 3.2vw, 2.5rem); line-height: 1.4; }
.final-cta p { max-width: 700px; margin: 0 auto 26px; color: var(--payback-paper); }
.final-cta-links { display: flex; flex-wrap: wrap; justify-content: center; gap: 12px; }
.final-cta-links a { display: inline-flex; min-height: 50px; align-items: center; justify-content: center; padding: 12px 22px; border: 1px solid var(--payback-paper); font-weight: 700; text-decoration: none; }
.primary-cta { background: var(--payback-paper); color: var(--payback-navy); }
.secondary-cta { background: transparent; color: var(--payback-paper); }
.final-cta-links a:hover { opacity: 0.9; }
.final-cta-links a:active { opacity: 0.8; }

@media (max-width: 768px) {
  .payback-container { padding: 18px 16px 64px; }
  .payback-hero { padding: 34px 0 32px; }
  .payback-hero h1 { font-size: clamp(2rem, 10vw, 3rem); }
  .article-meta { display: grid; grid-template-columns: 1fr; gap: 6px; }
  .direct-answer { margin-bottom: 56px; padding: 24px 20px; }
  .payback-section { margin-bottom: 58px; }
  .wide-section { margin-inline: -16px; margin-bottom: 60px; padding: 30px 16px; }
  .formula-list p { grid-template-columns: 1fr; gap: 4px; padding: 15px 16px; }
  .calculation-steps li { grid-template-columns: 1fr; gap: 5px; }
  .tendency-grid,
  .related-links { grid-template-columns: 1fr; }
  .check-list { columns: 1; }
  .simulator-callout { padding: 24px 20px; }
  .simulator-callout a,
  .section-link,
  .final-cta-links a { white-space: nowrap; }
  .simulator-callout a,
  .section-link { font-size: 0.9rem; }
  .responsive-table table,
  .responsive-table tbody,
  .responsive-table tr { display: block; width: 100%; }
  .responsive-table thead { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0; }
  .responsive-table tbody tr { border: 1px solid var(--payback-line); border-bottom: 0; }
  .responsive-table tbody tr:last-child { border-bottom: 1px solid var(--payback-line); }
  .responsive-table tbody th,
  .responsive-table tbody td { display: grid; grid-template-columns: minmax(90px, 0.7fr) minmax(0, 1.5fr); gap: 12px; width: 100%; padding: 12px 13px; border: 0; border-bottom: 1px solid var(--payback-line-light); }
  .responsive-table tbody tr > *:last-child { border-bottom: 0; }
  .responsive-table tbody th { display: block; background: var(--payback-blue-soft); }
  .responsive-table tbody td::before { content: attr(data-label); color: var(--payback-navy); font-size: 0.78rem; font-weight: 700; }
  .final-cta { margin: 68px -16px 0; padding: 38px 20px; }
  .final-cta-links { flex-direction: column; }
  .final-cta-links a { width: 100%; }
}

@media (max-width: 360px) {
  .payback-container { padding-inline: 12px; }
  .wide-section { margin-inline: -12px; padding-inline: 12px; }
  .responsive-table tbody th,
  .responsive-table tbody td { grid-template-columns: 82px minmax(0, 1fr); padding-inline: 10px; }
  .final-cta { margin-inline: -12px; }
}

@media (prefers-reduced-motion: reduce) {
  .solar-payback-page * { scroll-behavior: auto !important; transition-duration: 0.01ms !important; }
}