:root {
  color-scheme: light;
  --bg: #fafbf9;
  --surface: #f0f3ef;
  --text: #202722;
  --muted: #58625b;
  --accent: #a17430;
  --border: #d9deda;
  --inverse-bg: #121514;
  --inverse-text: #f4f2ed;
  --inverse-accent: #d6ad68;
  --focus-ring: var(--accent);
  --focus-width: 2px;
  --focus-offset: 5px;
  --target-min: 24px;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 24px; }
body { margin: 0; background: var(--bg); color: var(--text); font: 18px/1.75 "Segoe UI", Arial, sans-serif; }
a { color: inherit; text-underline-offset: .2em; }
a:focus-visible, summary:focus-visible { outline: var(--focus-width) solid var(--focus-ring); outline-offset: var(--focus-offset); }
.site-header { background: var(--inverse-bg); color: var(--inverse-text); }
.header-inner { max-width: 1180px; margin: auto; padding: 22px 32px; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.header-inner img { display: block; width: 230px; height: auto; }
.header-inner > a:last-child { font-size: 14px; text-decoration: none; }
.header-inner > a:last-child span { margin-left: 12px; color: var(--inverse-accent); }
main { max-width: 1180px; margin: auto; padding: 0 32px; }
.article-header { max-width: 1040px; margin-inline: auto; padding: 68px 0 38px; border-bottom: 1px solid var(--border); }
.article-label { display: flex; gap: 20px; align-items: center; font-size: 14px; color: var(--accent); }
.article-label > span:first-child { text-transform: uppercase; letter-spacing: .09em; }
.draft-label { color: var(--muted); border-left: 1px solid var(--border); padding-left: 20px; }
h1 { max-width: 24ch; font-size: clamp(2rem,4.1vw,3.5rem); line-height: 1.13; font-weight: 600; letter-spacing: -.035em; margin: 22px 0; text-wrap: balance; }
.introduction { max-width: 66ch; font-size: 21px; line-height: 1.65; color: var(--muted); margin: 0 0 30px; }
.article-meta { display: flex; flex-wrap: wrap; gap: 8px 24px; font-size: 14px; color: var(--muted); }
.article-meta > :last-child { margin-left: auto; font-family: ui-monospace, monospace; }
.reading-layout { max-width: 1040px; margin-inline: auto; display: grid; grid-template-columns: minmax(180px,220px) minmax(0,720px); justify-content: center; gap: clamp(44px,5vw,76px); padding-top: 44px; align-items: start; }
.contents { position: sticky; top: 24px; font-size: 14px; line-height: 1.45; }
.contents summary { min-height: var(--target-min); font-weight: 650; cursor: pointer; padding: 0 0 16px; }
.contents ol { list-style: none; padding: 0; margin: 0; border-top: 1px solid var(--border); }
.contents li { border-bottom: 1px solid var(--border); }
.contents a { display: grid; grid-template-columns: 22px 1fr; gap: 10px; padding: 13px 0; text-decoration: none; color: var(--muted); }
.contents a:hover { color: var(--accent); }
.contents a span { color: var(--accent); font-family: ui-monospace, monospace; }
.article-body { min-width: 0; }
.article-section { margin-bottom: 52px; scroll-margin-top: 28px; }
h2 { font-size: 27px; line-height: 1.3; font-weight: 600; letter-spacing: -.02em; margin: 0 0 22px; }
.article-section h2 { display: grid; grid-template-columns: 28px 1fr; gap: 14px; }
.section-number { font: 14px/2.5 ui-monospace, monospace; color: var(--accent); letter-spacing: 0; }
p { margin: 0 0 20px; }
ul { padding-left: 24px; margin: 20px 0; }
li { padding-left: 4px; }
.article-body li + li { margin-top: 7px; }
li::marker { color: var(--accent); }
.article-sources a { overflow-wrap: anywhere; }
.solar-diagram-embed { margin-inline: -24px; }
.solar-diagram-embed iframe { display: block; width: 100%; height: 1040px; border: 0; border-radius: 18px; background: #0d1b2a; }
.technical-note { border-left: 3px solid #bc975b; background: var(--surface); margin: 28px 0; padding: 20px 24px; }
.technical-note > span, .section-label { color: var(--muted); font-size: 14px; letter-spacing: .07em; text-transform: uppercase; }
.technical-note p { font-size: 21px; line-height: 1.5; margin: 8px 0 0; }
figure { margin: 28px 0; }
figure img { width: 100%; height: auto; display: block; }
figcaption { border-top: 1px solid var(--border); margin-top: 10px; padding-top: 8px; font-size: 14px; color: var(--muted); }
.faq-section { border-top: 1px solid var(--border); padding-top: 32px; margin-top: 60px; }
.section-label { margin-bottom: 10px; }
.faq-section details { border-bottom: 1px solid var(--border); }
.faq-section summary { min-height: var(--target-min); padding: 18px 0; cursor: pointer; font-size: 18px; font-weight: 600; line-height: 1.5; }
.faq-section p { color: var(--muted); }
.article-footer { max-width: 1040px; margin-inline: auto; display: flex; flex-wrap: wrap; gap: 14px; justify-content: space-between; padding: 34px 0 48px; font-size: 14px; color: var(--muted); }
@media (max-width: 760px) {
  .header-inner { padding: 18px 22px; gap: 16px; }
  .header-inner img { width: 175px; }
  .header-inner > a:last-child { max-width: 95px; text-align: right; line-height: 1.4; }
  .header-inner > a:last-child span { display: none; }
  main { padding: 0 22px; }
  .article-header { padding-top: 34px; padding-bottom: 26px; }
  h1 { font-size: clamp(2rem,7.6vw,2.7rem); margin-top: 18px; }
  .introduction { font-size: 19px; line-height: 1.65; }
  .article-meta { gap: 5px 16px; }
  .article-meta > :last-child { margin-left: 0; }
  .reading-layout { display: block; padding-top: 24px; }
  .contents { position: static; margin-bottom: 38px; }
  .contents a { font-size: 15px; }
  .article-section { margin-bottom: 42px; }
  h2 { font-size: 25px; }
  .article-section h2 { grid-template-columns: 22px 1fr; gap: 10px; }
  .technical-note { padding: 18px; }
  .technical-note p { font-size: 20px; }
  .solar-diagram-embed { margin-inline: 0; }
  .solar-diagram-embed iframe { height: 1220px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: 0s !important; }
}

.header-actions { display: flex; flex-wrap: wrap; gap: 12px 24px; align-items: center; justify-content: flex-end; }
.header-actions > a { min-height: var(--target-min); display: inline-flex; align-items: center; font-size: 14px; text-decoration: none; }
.article-languages { display: flex; gap: 4px; }
.article-languages a { display: inline-flex; min-width: 44px; min-height: 44px; align-items: center; justify-content: center; text-decoration: none; font-size: 14px; }
.article-languages a[aria-current="page"] { color: var(--inverse-accent); border-bottom: 2px solid currentColor; }
.article-meta > :last-child { margin-left: 0; font-family: inherit; }
.skip-link { position: absolute; left: 12px; top: -100px; background: white; color: var(--text); padding: 10px; z-index: 5; }
.skip-link:focus { top: 8px; }
.catalog-grid { list-style: none; padding: 0; margin: 40px auto 80px; max-width: 1040px; display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 28px; }
.catalog-card { padding: 0; border: 1px solid var(--border); border-radius: 12px; overflow: hidden; background: var(--surface); }
.catalog-card article { height: 100%; display: flex; flex-direction: column; }
.catalog-card img { display: block; width: 100%; height: 280px; object-fit: cover; }
.catalog-card-copy { display: flex; flex-direction: column; flex: 1; padding: 26px; }
.catalog-card h2 { font-size: 26px; margin: 10px 0 18px; overflow-wrap: anywhere; }
.catalog-card h2 a { text-decoration: none; }
.catalog-card h2 a:hover { text-decoration: underline; }
.catalog-card-copy > p:not(.article-label) { color: var(--muted); font-size: 16px; }
.catalog-card time { margin-top: auto; color: var(--muted); font-size: 14px; }
.catalog-read { display: inline-flex; align-items: center; min-height: 44px; margin-top: 14px; font-size: 16px; }
@media (max-width: 760px) { .catalog-grid { grid-template-columns: 1fr; } .catalog-card-copy { padding: 20px; } .catalog-card img { height: 240px; } }
@media (max-width: 760px) { .header-inner { flex-wrap: wrap; } .header-actions { gap: 4px 12px; } .header-inner img { width: 160px; } }