/* Shared OY LAND shell. Page-specific imagery and reading layouts keep their identity. */
:root {
  --oy-ink: #10294a;
  --oy-blue: #1952bb;
  --oy-muted: #526e8c;
  --oy-line: #d5e2ef;
  --oy-paper: #f9fcff;
  --oy-gutter: clamp(20px, 5.3vw, 88px);
  --oy-header-height: 78px;
  --oy-ease: cubic-bezier(.16, 1, .3, 1);
  --oy-section-title: clamp(30px, 3.4vw, 44px);
}
html:has(.oy-site) { scroll-padding-top: calc(var(--oy-header-height) + 20px); }
.oy-site :is(a, button, summary, input, select):focus-visible { outline: 2px solid var(--oy-blue); outline-offset: 5px; }
.oy-site > .oy-header {
  position: sticky; top: 0; z-index: 50; height: var(--oy-header-height); min-height: var(--oy-header-height);
  display: flex; align-items: center; gap: 24px; padding: 0 max(var(--oy-gutter), calc((100vw - 1440px) / 2));
  border: 0; border-bottom: 1px solid var(--oy-line); background: var(--oy-paper); backdrop-filter: none;
  color: var(--oy-ink); font-family: "PingFang SC", "Microsoft YaHei", sans-serif;
}
.oy-site > .hn-site-header { position: fixed; background: transparent; border-bottom-color: transparent; }
.oy-site > .hn-site-header:is(.hn-scrolled, .hn-menu-open) { background: var(--oy-paper); border-bottom-color: var(--oy-line); box-shadow: none; }
.oy-site .oy-brand {
  display: inline-flex; flex: none; align-items: center; gap: 8px; margin: 0; padding: 0;
  color: #1d5bbd; text-decoration: none; white-space: nowrap; line-height: 1;
}
.oy-site .oy-brand > svg { display: block; flex: none; width: 28px; height: 36px; color: #46a6f2; }
.oy-site .oy-brand > .oy-wordmark { display: block; margin: 0; padding: 0; border: 0; font-size: 22px; font-weight: 700; letter-spacing: .015em; line-height: 1; }
.oy-site .oy-wordmark small { display: block; margin: 7px 0 0; font-size: 8px; font-weight: 400; line-height: 1; letter-spacing: .1em; color: #58779e; }
.oy-site .oy-header > .oy-nav { display: flex; align-items: center; justify-content: center; gap: clamp(12px, 1.3vw, 20px); margin: 0 0 0 auto; padding: 0; background: none; border: 0; box-shadow: none; }
.oy-site .oy-header > .oy-nav a {
  position: relative; display: inline-flex; align-items: center; justify-content: center; min-height: 44px;
  margin: 0; padding: 10px 0; color: var(--oy-ink); font-size: 12px; font-weight: 500; line-height: 1.4;
  white-space: nowrap; text-decoration: none; border: 0; background: none;
  transition: color 160ms ease;
}
.oy-site .oy-header > .oy-nav a::after { content: ""; position: absolute; left: 0; right: 0; bottom: 2px; height: 2px; background: var(--oy-blue); transform: scaleX(0); transform-origin: center; transition: transform 200ms var(--oy-ease); }
.oy-site .oy-header > .oy-nav a:is([aria-current="page"], [aria-current="true"], .active) { color: var(--oy-blue); text-decoration: none; box-shadow: none; }
.oy-site .oy-header > .oy-nav a:is([aria-current="page"], [aria-current="true"], .active)::after { transform: scaleX(1); }
.oy-site .oy-header > .oy-nav a:hover { color: var(--oy-blue); }
.oy-site .oy-header-actions { display: flex; align-items: center; flex: none; gap: 14px; margin-left: 0; white-space: nowrap; }
.oy-site .oy-login { display: inline-flex; align-items: center; min-height: 44px; font-size: 12px; font-weight: 500; color: var(--oy-ink); text-decoration: none; }
.oy-site .oy-header .oy-contact {
  display: inline-flex; align-items: center; justify-content: center; min-height: 40px; margin: 0; padding: 10px 15px;
  border: 0; border-radius: 24px; background: var(--oy-blue); color: #fff; box-shadow: none;
  font-family: inherit; font-size: 12px; font-weight: 500; line-height: 1.5; text-decoration: none;
  transform: none; transition: background-color 160ms ease; cursor: pointer;
}
.oy-site .oy-header .oy-contact:hover { background: #123f91; transform: none; }
.oy-site .oy-header .oy-menu { display: none; flex: none; place-items: center; width: 40px; height: 44px; padding: 10px; border: 0; border-radius: 6px; background: transparent; color: var(--oy-ink); box-shadow: none; cursor: pointer; }
.oy-site .oy-menu span { display: block; height: 1.5px; width: 20px; margin: 5px 0; background: currentColor; }
.oy-site .oy-menu svg { width: 22px; height: 22px; }
.oy-site > .oy-tool-header { position: relative; height: auto; min-height: 78px; display: flex; align-items: center; justify-content: space-between; gap: 24px; padding: 20px var(--oy-gutter); background: var(--oy-paper); border-bottom: 1px solid var(--oy-line); }
.oy-site .oy-tool-name { margin-left: 8px; padding-left: 16px; border-left: 1px solid #bfd0e1; font-size: 12px; font-weight: 500; color: var(--oy-ink); }
.oy-site .oy-tool-header nav { gap: 24px; margin: 0; }
.oy-site .oy-tool-header nav a { font-size: 12px; }
.oy-site :is(.faculty-shell, .growth-shell, .activity-shell, .history-shell) { width: min(1280px, calc(100% - var(--oy-gutter) * 2)); margin-inline: auto; }
.oy-site :is(.course-hero, .curriculum-section, .benefit-section, .learning-section) { padding-inline: max(var(--oy-gutter), calc((100vw - 1280px) / 2)); }
.oy-site .course-hero { padding-top: 64px; }
.oy-site .course-2027-intro { width: min(1280px, calc(100% - var(--oy-gutter) * 2)); padding-inline: 0; }
.oy-site .faculty-toc { top: var(--oy-header-height); z-index: 35; }
.oy-site .faculty-toc a { transition: color 160ms ease, background-color 160ms ease; }
.oy-site .faculty-toc a[aria-current="location"] { background: #eaf2fd; border-bottom-color: var(--oy-blue); }
.oy-site :is(#story, #selectedWorks, #springFestival, #archive, #collaborations, #teaching) { scroll-margin-top: calc(var(--oy-header-height) + 66px); }
.oy-site .section-intro h2 { font-size: var(--oy-section-title); line-height: 1.25; }
.oy-site :is(.section-intro, .section-heading) > p { color: var(--oy-muted); }

/* The homepage moves from the sky into portraits, records and shared memories. */
.oy-site.daylight-home .page-shell { width: min(1280px, calc(100% - var(--oy-gutter) * 2)); }
.oy-site.daylight-home :is(.teacher-name, .student-works-header h2, .home-growth-heading h2, .home-course-copy > h2, .daylight-intro h2, .home-lab-intro h2, .audience h2, .faq h2, .final-cta h2) { font-size: var(--oy-section-title); line-height: 1.25; letter-spacing: -.025em; }
.oy-site.daylight-home .proof { position: relative; padding-block: 78px 84px; }
.oy-site.daylight-home .proof-inner { gap: clamp(32px, 5vw, 72px); grid-template-columns: minmax(0, .85fr) minmax(0, 1.15fr); }
.oy-site.daylight-home .teacher-name { margin-bottom: 22px; }
.oy-site.daylight-home .teacher-summary { font-size: clamp(20px, 1.85vw, 25px); line-height: 1.65; }
.oy-site.daylight-home .teacher-evidence { gap: 22px 16px; margin-top: 18px; }
.oy-site.daylight-home .teacher-evidence dt { font-size: clamp(24px, 2.2vw, 30px); }
.oy-site.daylight-home .learning { padding-block: 68px; }
.oy-site.daylight-home .student-works { padding-block: 76px 80px; background: #eff6fd; }
.oy-site.daylight-home .student-works-header { gap: 32px; grid-template-columns: 1fr auto; margin-bottom: 28px; }
.oy-site.daylight-home .student-works-header p { margin-top: 16px; font-size: 16px; letter-spacing: 0; }
.oy-site.daylight-home .works-filter { margin: 0; }
.oy-site.daylight-home .works-filter button { box-shadow: none; font-weight: 600; transition: background-color 180ms ease, color 180ms ease; }
.oy-site.daylight-home .works-orbit { margin-inline: calc((100vw - min(1280px, calc(100vw - var(--oy-gutter) * 2))) / -2); }
.oy-site.daylight-home .work-detail-shell { box-shadow: 0 16px 38px -24px #254f8052; }
.oy-site.daylight-home .home-growth { padding-block: 76px; background: #fff; }
.oy-site.daylight-home .world-news { padding-block: 72px 64px; background: #f5f9fd; }
.oy-site.daylight-home .daylight-intro { padding-bottom: 30px; }
.oy-site.daylight-home .daylight-chapter { padding-block: 60px; gap: 42px; }
.oy-site.daylight-home .daylight-copy h3 { font-size: clamp(30px, 3vw, 40px); line-height: 1.3; }
.oy-site.daylight-home .daylight-copy p { margin-block: 20px; line-height: 1.85; }
.oy-site.daylight-home .daylight-keepsakes { margin-top: 8px; padding-bottom: 20px; }
.oy-site.daylight-home :is(.audience, .faq) { padding-block: 68px; }
.oy-site.daylight-home .faq-list details[open] { background: #eaf2fb; }
.oy-site.daylight-home .student-work-card { transition: transform 320ms var(--oy-ease), opacity 240ms ease, filter 240ms ease; }
.oy-site.daylight-home .student-work-card.is-playing h3 { text-decoration: underline; text-underline-offset: 6px; text-decoration-thickness: 2px; }
.oy-site.daylight-home .work-audio-player.is-playing { background: #edf5ff; }
.oy-site.daylight-home .work-audio-player { transition: background-color 180ms ease; }
.oy-site.daylight-home .work-playback-status { margin: 8px 0 0; min-height: 20px; font-size: 12px; color: var(--oy-muted); }

.oy-site .growth-hero { padding-top: 64px; min-height: 0; }
.oy-site.daylight-culture .cohort-gallery { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 48px 36px; }
.oy-site.daylight-culture .cohort-card:nth-child(n) figure { transform: none; }
.oy-site.daylight-culture .cohort-card:nth-child(even) figure { transform: rotate(.45deg); }
.oy-site.daylight-culture .cohort-card:nth-child(odd) figure { transform: rotate(-.45deg); }
.oy-site.daylight-culture .daylight-photo-open { position: relative; }
.oy-site.daylight-culture .daylight-photo-open::after { content: "查看大图 ↗"; position: absolute; right: 10px; bottom: 10px; padding: 7px 10px; border-radius: 4px; background: #f9fcfff0; color: var(--oy-ink); font-size: 11px; line-height: 1.3; opacity: 0; transition: opacity 160ms ease; }
.oy-site.daylight-culture .daylight-photo-open:is(:hover, :focus-visible)::after { opacity: 1; }
.oy-site.daylight-activities .story-entry.journey-current::before { outline: 3px solid #d6e8fa; outline-offset: 3px; }
.oy-site.daylight-activities .story-entry.journey-current .story-meta time { color: var(--oy-blue); }
.oy-site :is(.studio-lightbox, .daylight-photo-dialog, .culture-meme-dialog, #photoLightbox) img { transform-origin: center; }

@media (max-width: 1100px) {
  .oy-site > .oy-header { gap: 18px; }
  .oy-site .oy-header-actions { margin-left: auto; }
  .oy-site .oy-header .oy-menu { display: block; }
  .oy-site .oy-header > .oy-nav {
    display: none; position: absolute; inset: var(--oy-header-height) 0 auto; margin: 0; padding: 16px var(--oy-gutter) 22px;
    grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 8px 20px; border-radius: 0; border-bottom: 1px solid var(--oy-line);
    background: var(--oy-paper); max-height: calc(100dvh - var(--oy-header-height)); overflow-y: auto;
  }
  .oy-site .oy-header:has(.oy-menu[aria-expanded="true"]) > .oy-nav { display: grid; }
  .oy-site .oy-header > .oy-nav a { min-height: 44px; padding: 12px 0; font-size: 14px; }
  .oy-site .oy-header > .oy-nav a::after { left: 30%; right: 30%; }
}
@media (max-width: 700px) {
  :root { --oy-header-height: 65px; --oy-gutter: 20px; }
  .oy-site > .oy-header { gap: 10px; }
  .oy-site .oy-brand { gap: 5px; }
  .oy-site .oy-brand > svg { width: 23px; height: 32px; }
  .oy-site .oy-brand > .oy-wordmark { font-size: 19px; }
  .oy-site .oy-wordmark small { display: none; }
  .oy-site .oy-header-actions { gap: 9px; }
  .oy-site .oy-login { font-size: 11px; }
  .oy-site .oy-header .oy-contact { min-height: 36px; padding: 8px 10px; font-size: 11px; }
  .oy-site .oy-header .oy-menu { width: 30px; padding: 5px; }
  .oy-site .oy-header > .oy-nav { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .oy-site > .oy-tool-header { flex-wrap: wrap; gap: 14px; padding: 18px 20px; }
  .oy-site .oy-tool-header nav { display: flex; flex-wrap: wrap; gap: 8px 16px; }
  .oy-site .oy-tool-header nav a { min-height: 32px; display: inline-flex; align-items: center; }
  .oy-site .chapter-navigation { top: var(--oy-header-height); z-index: 30; }
  .oy-site .chapter-panel { scroll-margin-top: calc(var(--oy-header-height) + 88px); }
  .oy-site.daylight-home .proof { padding-block: 52px; }
  .oy-site.daylight-home .proof-inner { grid-template-columns: minmax(0, 1fr); gap: 32px; }
  .oy-site.daylight-home :is(.learning, .student-works, .home-growth, .world-news, .audience, .faq) { padding-block: 48px; }
  .oy-site.daylight-home .student-works-header { grid-template-columns: minmax(0, 1fr); gap: 22px; }
  .oy-site.daylight-home .student-works-header p { font-size: 15px; }
  .oy-site.daylight-home .daylight-chapter { gap: 28px; padding-block: 42px; }
  .oy-site.daylight-home .daylight-copy h3 { font-size: 30px; }
  .oy-site.daylight-home .daylight-keepsakes { padding-bottom: 0; }
  .oy-site.daylight-home .works-filter { justify-content: flex-start; margin: 0; }
  .oy-site .growth-hero { padding-top: 32px; }
  .oy-site.daylight-culture .cohort-gallery { gap: 30px 18px; }
  .oy-site.daylight-culture .daylight-photo-open::after { opacity: 1; font-size: 10px; padding: 5px 7px; }
}
@media (max-width: 620px) {
  .oy-site .featured-story { min-height: 0; background: white; color: var(--oy-ink); border: 1px solid var(--oy-line); box-shadow: none; }
  .oy-site .featured-story::after { content: none; }
  .oy-site .featured-story > img { position: static; width: 100%; height: auto; aspect-ratio: 4 / 3; object-position: center 38%; }
  .oy-site .featured-content { width: 100%; min-height: 0; padding: 24px; }
  .oy-site .featured-content > span { margin-bottom: 20px; }
  .oy-site .featured-content :is(p, .story-meta) { color: var(--oy-muted); }
  .oy-site .featured-content .story-link { background: var(--oy-blue); color: white; margin-top: 20px; }
  .oy-site .featured-story--art > img { height: 250px; aspect-ratio: auto; object-fit: contain; padding: 24px; }
}
@media (max-width: 370px) {
  :root { --oy-gutter: 14px; }
  .oy-site .oy-brand > .oy-wordmark { font-size: 17px; }
  .oy-site .oy-brand > svg { width: 20px; }
  .oy-site .oy-header-actions { gap: 6px; }
  .oy-site .oy-login, .oy-site .oy-header .oy-contact { font-size: 10px; }
  .oy-site .oy-header .oy-contact { padding-inline: 8px; }
}
@media (prefers-reduced-motion: reduce) {
  .oy-site .oy-header *, .oy-site .oy-header *::after, .oy-site .daylight-photo-open::after { transition: none !important; }
}