.detail-page { min-height: 100dvh; background: var(--paper); }
.detail-page::before { display: none; }
.detail-topbar { background: var(--paper); }
.detail-shell { width: min(900px, 86vw); margin: 0 auto; padding: 104px 0 56px; text-align: center; }
.detail-heading { margin: 0; font-size: clamp(34px, 4.2vw, 56px); font-weight: 500; line-height: 1.08; letter-spacing: -.025em; }
.detail-lead { max-width: 560px; margin: 15px auto 34px; color: var(--ink-soft); font-size: 15px; line-height: 1.7; }

.faq-list { width: min(720px, 100%); margin: 32px auto 0; border-top: 1px solid var(--line); }
.faq-list details { border-bottom: 1px solid var(--line); }
.faq-list summary { display: grid; grid-template-columns: 1fr auto; align-items: center; padding: 17px 10px 17px 24px; cursor: pointer; list-style: none; font-size: clamp(17px, 1.45vw, 21px); text-align: left; }
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary::after { content: "+"; font: 24px/1 ui-sans-serif, system-ui, sans-serif; transition: transform .22s ease; }
.faq-list summary:hover { color: var(--vermilion); background: rgba(255,251,243,.24); }
.faq-list summary:focus-visible { outline: 2px solid var(--vermilion); outline-offset: -2px; }
.faq-list details[open] summary::after { transform: rotate(45deg); }
.faq-list details p { margin: -2px 0 22px; padding: 0 54px 0 24px; color: var(--ink-soft); font-size: 14px; line-height: 1.8; text-align: left; }

/* Labs: project sketches, with the existing paper and ink palette. */
.labs-shell { width: min(1200px, 88vw); text-align: left; }
.labs-intro { padding: 24px 0 36px; }
.labs-intro .detail-lead { max-width: none; margin: 18px 0 12px; font-size: clamp(20px, 2.5vw, 28px); color: var(--ink); }
.labs-note, .labs-more { color: var(--ink-soft); font-size: 13px; line-height: 1.8; }
.labs-list { border-top: 1px solid var(--line); }
.lab-item { display: grid; grid-template-columns: .75fr 1.25fr; gap: clamp(28px, 4vw, 56px); align-items: center; padding: 38px 0; border-bottom: 1px solid var(--line); }
.lab-number { display: block; color: var(--vermilion); font: 12px/1.5 ui-monospace, monospace; margin-bottom: 14px; }
.lab-item h2 { margin: 0; font-size: clamp(24px, 2.5vw, 32px); line-height: 1.5; text-wrap: balance; }
.lab-item p { margin: 16px 0; color: var(--ink-soft); font-size: 14px; line-height: 1.9; }
.lab-caption { display: block; margin-top: 22px; font-size: 12px; color: var(--vermilion); }
.lab-scene { min-width: 0; margin: 0; }
.lab-preview { position: relative; display: block; }
.lab-preview img { display: block; width: 100%; height: auto; border: 1px solid var(--line); }
.lab-preview:hover img { border-color: var(--vermilion); }
.lab-expand { position: absolute; right: 12px; bottom: 12px; padding: 6px 10px; color: var(--ink); background: var(--paper-light); border: 1px solid var(--line); font: 11px/1.4 ui-sans-serif, system-ui, sans-serif; }
.lab-scene figcaption { margin-top: 10px; color: var(--ink-soft); font-size: 12px; line-height: 1.6; }
.labs-more { margin: 32px 0 0; text-align: center; }

.feedback-shell { width: min(960px, 90vw); padding-top: 94px; }
.feedback-shell .detail-lead { margin-bottom: 24px; }
.feedback-form { display: grid; gap: 22px; width: min(760px, 100%); margin: 0 auto; padding-top: 24px; border-top: 1px solid var(--line); text-align: left; }
.feedback-kind { min-width: 0; margin: 0; padding: 0; border: 0; }
.feedback-kind legend, .feedback-field > span { margin-bottom: 10px; color: #62584d; font-family: "WeiBei Stele", serif; font-size: 13px; font-weight: 400; letter-spacing: .065em; }
.feedback-kind-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; }
.feedback-kind-option { position: relative; display: block; cursor: pointer; }
.feedback-kind-option input { position: absolute; width: 1px; height: 1px; opacity: 0; }
.feedback-kind-option > span { display: grid; gap: 5px; min-height: 66px; padding: 12px 14px; border: 1px solid rgba(54,47,40,.2); background: rgba(255,251,243,.16); transition: border-color .2s ease, background .2s ease, transform .2s ease; }
.feedback-kind-option strong { color: var(--ink); font-family: "WeiBei Stele", serif; font-size: 14px; font-weight: 400; letter-spacing: .055em; }
.feedback-kind-option small { color: var(--ink-soft); font: 10px/1.2 ui-monospace, SFMono-Regular, Menlo, monospace; }
.feedback-kind-option:hover > span { border-color: rgba(54,47,40,.42); background: rgba(255,251,243,.32); }
.feedback-kind-option input:checked + span { border-color: var(--vermilion); background: rgba(185,52,32,.055); box-shadow: inset 3px 0 0 var(--vermilion); }
.feedback-kind-option input:focus-visible + span { outline: 2px solid var(--vermilion); outline-offset: 3px; }
.feedback-kind-option:active > span { transform: translateY(1px); }
.feedback-field { display: grid; }
.feedback-form input[type="text"], .feedback-form textarea { width: 100%; border: 0; border-bottom: 1px solid rgba(54,47,40,.3); border-radius: 0; color: var(--ink); background: rgba(255,251,243,.24); font: 16px/1.65 "Songti SC", "STSong", "Noto Serif CJK SC", serif; outline: 0; transition: border-color .2s ease, background .2s ease; }
.feedback-form input[type="text"] { height: 48px; padding: 0 12px; }
.feedback-form textarea { min-height: 126px; padding: 12px; resize: vertical; }
.feedback-form input[type="text"]:focus, .feedback-form textarea:focus { border-color: var(--vermilion); background: rgba(255,251,243,.52); }
.feedback-form input::placeholder, .feedback-form textarea::placeholder { color: #81766a; opacity: 1; }
.feedback-footer { display: grid; grid-template-columns: 1fr auto; align-items: center; gap: 24px; }
.feedback-disclosure { max-width: 460px; margin: 0; color: #6b6156; font-size: 12px; line-height: 1.65; }
.feedback-submit { min-width: 188px; padding: 13px 22px; border: 1px solid #2d2823; color: #f7eddb; background: #2d2823; font: 14px "WeiBei Stele", serif; letter-spacing: .055em; white-space: nowrap; cursor: pointer; transition: color .2s ease, background .2s ease, transform .2s ease; }
.feedback-submit:hover { color: #2d2823; background: transparent; }
.feedback-submit:active { transform: translateY(1px); }
.feedback-status { min-height: 18px; margin: -10px 0 0; color: var(--vermilion); font-size: 12px; text-align: right; }
:is(.detail-heading, .detail-lead, .faq-list summary, .lab-item h2) { font-family: "WeiBei Stele", serif; font-weight: 400; letter-spacing: .065em; }

@media (max-width: 760px) {
  .detail-shell { width: 88vw; padding: 120px 0 48px; }
  .detail-heading { font-size: 34px; }
  .detail-lead { margin: 12px auto 24px; font-size: 14px; }
  .faq-list { margin-top: 24px; }
  .faq-list summary { padding: 15px 8px 15px 12px; font-size: 17px; }
  .faq-list details p { padding: 0 34px 0 12px; font-size: 13px; }
  .labs-intro { padding: 0 0 24px; }
  .lab-item { grid-template-columns: 1fr; gap: 24px; padding: 28px 0; }
  .lab-item h2 { font-size: 25px; }
  .lab-caption { margin-top: 14px; }
  .lab-expand { right: 8px; bottom: 8px; }
  .feedback-shell { width: 88vw; padding-top: 120px; }
  .feedback-kind-grid { grid-template-columns: 1fr 1fr; }
  .feedback-kind-option > span { min-height: 62px; padding: 11px 12px; }
  .feedback-footer { grid-template-columns: 1fr; gap: 14px; }
  .feedback-submit { width: 100%; }
  .feedback-status { text-align: left; }
}


.guide-shell { max-width: 960px; }
.guide-shell section { max-width: 42em; margin: 48px auto; scroll-margin-top: 116px; text-align: left; }
.guide-shell h2 { font-size: clamp(21px, 3vw, 28px); font-weight: 500; line-height: 1.5; }
.guide-shell p, .guide-shell li { line-height: 1.9; }
.guide-shell section > p, .guide-shell li { color: var(--ink-soft); }
.guide-shell ol { padding-left: 1.5em; }
.guide-index, .guide-links { display: flex; flex-wrap: wrap; justify-content: center; gap: 12px 24px; }
.guide-shell section .guide-links { justify-content: flex-start; }
.guide-index a, .guide-links a { padding: 8px 0; }
.guide-index a:hover, .guide-links a:hover { color: var(--vermilion); }
.guide-shell a { text-decoration: underline; text-underline-offset: 4px; }
.guide-screenshot { display: block; width: 100%; height: auto; margin: 32px 0; }
.guide-shell pre { overflow-x: auto; padding: 20px; background: rgba(255,255,255,.35); font-size: 13px; line-height: 1.8; }
@media (max-width: 760px) {
  .guide-shell .detail-heading { font-size: 30px; line-height: 1.35; text-wrap: balance; }
  .guide-shell section { margin: 36px 0; }
  .guide-index { gap: 4px 20px; }
}