:root { --xy-accent: #236774; --xy-muted: #60717a; --xy-border: #e1e7e9; --xy-soft: #edf3f3; }
[data-user-color-scheme="dark"] { --xy-accent: #92d2d1; --xy-muted: #a2b0bc; --xy-border: #34434e; --xy-soft: #25353e; }
html { scroll-behavior: smooth; scroll-padding-top: 90px; }
body { line-height: 1.75; }
a:focus-visible, button:focus-visible { outline: 3px solid var(--xy-accent); outline-offset: 5px; border-radius: 3px; }
.skip-link { position: fixed; top: -90px; left: 16px; z-index: 9999; padding: 10px 18px; background: var(--board-bg-color); color: var(--text-color); }
.skip-link:focus { top: 16px; }
.navbar { box-shadow: none; }
.navbar .navbar-brand { display: flex; align-items: center; gap: 18px; }
.navbar-brand strong { font-size: 1.3rem; letter-spacing: .16em; }
.brand-note { padding-left: 18px; border-left: 1px solid #ffffff40; font-size: .72rem; letter-spacing: .06em; font-weight: 400; opacity: .8; }
.navbar .nav-item .nav-link { font-size: .9rem; margin: 0 .2rem; padding: .5rem .75rem; }
.navbar .nav-link.active { font-weight: 650; text-underline-offset: 8px; text-decoration: underline; text-decoration-thickness: 2px; }
.top-nav-collapse, .navbar-col-show { box-shadow: 0 2px 12px #12283412; }
.home-page .header-inner { min-height: 435px; max-height: 600px; }
#banner { background-image: var(--banner-image); }
@media (max-width: 767px) { #banner { background-image: var(--banner-image-mobile); } }
.home-page #banner { background-position: center 55% !important; }
.home-page .full-bg-img .mask { background: linear-gradient(90deg, #102832d9 0%, #142e35a6 40%, #142e3526 100%); }
.hero-container { position: relative; display: flex; align-items: center; height: 100%; padding-top: 56px; padding-bottom: 32px; }
.home-hero { max-width: 740px; color: #fff; }
.hero-eyebrow { font-size: .76rem; letter-spacing: .14em; color: #d4e5e8; margin: 0 0 10px; }
.home-hero #subtitle { font-size: clamp(2.8rem, 5vw, 4rem); font-weight: 650; letter-spacing: .16em; line-height: 1.2; margin: 0 0 14px; }
.hero-intro { font-size: clamp(1.15rem, 2.2vw, 1.55rem); line-height: 1.5; font-weight: 450; margin-bottom: 12px; letter-spacing: .035em; }
.hero-description { color: #d8e5e8; font-size: .9rem; max-width: 530px; margin: 0; line-height: 1.9; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 23px; }
.hero-button { display: inline-flex; align-items: center; gap: 28px; padding: 9px 19px; border-radius: 5px; font-size: .86rem; font-weight: 550; border: 1px solid #ffffff70; }
.hero-button-primary, .hero-button-primary:hover { background: #f3f8f7; border-color: #f3f8f7; color: #203c46; }
.hero-button-secondary { color: #fff; background: #ffffff08; }
.hero-button-secondary:hover { background: #ffffff20; color: #fff; }
.home-page #board { margin-top: 0; padding: 42px 0 0; background: transparent; box-shadow: none; border-radius: 0; }
.home-section { margin-bottom: 42px; scroll-margin-top: 90px; }
.section-heading { display: flex; align-items: flex-end; justify-content: space-between; gap: 20px; margin-bottom: 22px; }
.section-kicker { color: var(--xy-accent); font-size: .72rem; letter-spacing: .1em; font-weight: 600; margin: 0 0 5px; }
.section-heading h2 { color: var(--text-color); font-size: 1.4rem; font-weight: 650; margin: 0; line-height: 1.4; }
.section-heading > a { color: var(--xy-muted); font-size: .8rem; flex-shrink: 0; }
.section-heading a:hover { color: var(--xy-accent); }
.featured-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 20px; }
.featured-card { display: flex; flex-direction: column; min-width: 0; padding: 25px 25px 20px; border: 1px solid var(--xy-border); border-radius: 10px; background: var(--board-bg-color); transition: border-color .2s, box-shadow .2s; }
.featured-card:hover { border-color: var(--xy-accent); box-shadow: 0 8px 22px #12283408; }
.card-topline { display: flex; justify-content: space-between; align-items: center; gap: 8px; color: var(--xy-accent); font-size: .73rem; margin-bottom: 19px; }
.card-number { font-size: 1.25rem; color: var(--xy-muted); opacity: .5; font-weight: 350; font-variant-numeric: tabular-nums; }
.featured-card h3 { font-size: 1.19rem; font-weight: 650; line-height: 1.55; color: var(--text-color); margin: 0 0 11px; }
.featured-card p { color: var(--xy-muted); font-size: .84rem; line-height: 1.85; flex: 1; margin: 0 0 22px; }
.card-bottom { display: flex; justify-content: space-between; align-items: center; color: var(--xy-muted); font-size: .73rem; }
.card-bottom > span { color: var(--xy-accent); font-size: 1.1rem; }
.topic-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 0; border: 1px solid var(--xy-border); background: var(--board-bg-color); border-radius: 10px; overflow: hidden; }
.topic-card { padding: 24px 22px; border-right: 1px solid var(--xy-border); display: flex; flex-direction: column; }
.topic-card:last-child { border-right: 0; }
.topic-card:hover { background: var(--xy-soft); }
.topic-label { color: var(--xy-muted); display: block; font-size: .58rem; letter-spacing: .08em; line-height: 1.6; }
.topic-card h3 { font-size: 1.08rem; font-weight: 650; margin: 9px 0 10px; color: var(--text-color); }
.topic-card p { color: var(--xy-muted); font-size: .8rem; line-height: 1.85; margin-bottom: 16px; flex: 1; }
.topic-count { font-size: .72rem; color: var(--xy-accent); }
.topic-count > span { float: right; }
.recent-list { background: var(--board-bg-color); border: 1px solid var(--xy-border); border-radius: 10px; padding: 5px 28px; }
.recent-item { display: grid; grid-template-columns: 92px minmax(0, 1fr) auto; gap: 22px; padding: 23px 0; align-items: start; border-bottom: 1px solid var(--xy-border); }
.recent-item:last-child { border-bottom: none; }
.recent-item > time { color: var(--xy-muted); font-size: .74rem; padding-top: 3px; font-variant-numeric: tabular-nums; }
.recent-content h3 { font-size: 1rem; font-weight: 600; margin: 0 0 5px; line-height: 1.6; }
.recent-content p { font-size: .8rem; line-height: 1.8; color: var(--xy-muted); margin: 0; }
.recent-category { font-size: .7rem; color: var(--xy-accent); background: var(--xy-soft); border-radius: 4px; padding: 2px 9px; margin-top: 1px; }
.series-note { display: flex; align-items: center; justify-content: space-between; gap: 24px; padding: 23px 0 0; }
.series-note p { font-size: .8rem; color: var(--xy-muted); margin: 5px 0 0; }
.series-note > a { flex-shrink: 0; color: var(--xy-accent); font-size: .8rem; }
#board { box-shadow: 0 4px 28px #162d3610; border-radius: 12px; }
.inner-page .header-inner { min-height: 260px; max-height: 360px; }
.post-page .header-inner { min-height: 300px; max-height: 440px; }
.banner-title { font-size: clamp(1.65rem, 3vw, 2.1rem); font-weight: 600; line-height: 1.6; margin: 0; }
.banner-text { padding: 64px 24px 24px; }
.topics-intro { margin-bottom: 28px; }
.topics-intro h2 { font-size: 1.5rem; font-weight: 650; margin: 8px 0 12px; }
.topics-intro > p:last-child { color: var(--xy-muted); font-size: .9rem; }
.topics-intro a { color: var(--xy-accent); }
.topic-directory { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 22px; }
.topic-directory-card { padding: 24px; border: 1px solid var(--xy-border); border-radius: 9px; }
.topic-directory-card .card-topline { margin-bottom: 13px; }
.topic-directory-card h2 { font-size: 1.15rem; font-weight: 650; margin: 0 0 10px; }
.topic-directory-card h2 span { font-size: .9rem; color: var(--xy-accent); float: right; }
.topic-directory-card > p { font-size: .8rem; color: var(--xy-muted); }
.topic-directory-card ul { list-style: none; padding: 13px 0 7px; margin: 0; border-top: 1px solid var(--xy-border); }
.topic-directory-card li { font-size: .8rem; margin-bottom: 10px; line-height: 1.7; }
.directory-more { font-size: .76rem; color: var(--xy-accent); }
.post-content { padding-left: clamp(20px, 4vw, 60px); padding-right: clamp(20px, 4vw, 60px); }
.markdown-body { font-size: 16px; line-height: 1.95; }
.markdown-body p { margin-bottom: 1.2em; }
.markdown-body h2, .markdown-body h3, .markdown-body h4 { scroll-margin-top: 96px; line-height: 1.55; }
.markdown-body h2 { margin-top: 2.1em; font-size: 1.4rem; }
.markdown-body h3 { font-size: 1.13rem; }
.markdown-body pre { line-height: 1.75; font-size: .84rem; }
.markdown-body figure { max-width: 100%; }
.toc { font-size: .8rem; line-height: 1.8; }
.index-card { margin-bottom: 1.5rem; padding-bottom: 1.5rem; border-bottom: 1px solid var(--xy-border); }
.index-header { white-space: normal; font-size: 1.2rem; line-height: 1.6; }
.about-content { margin-top: 2rem !important; }
.about-intro { color: var(--xy-muted); }
footer { padding: 15px 15px 28px; font-size: .78rem; color: var(--xy-muted); }
.footer-separator { margin: 0 9px; }
.footer-credit { display: inline-block; margin-top: 8px; font-size: .67rem; opacity: .8; }
@media (max-width: 991px) {
  .brand-note { display: none; }
  .featured-grid { gap: 12px; }
  .featured-card { padding: 21px 18px 18px; }
  .featured-card h3 { font-size: 1.08rem; }
  .topic-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .topic-card:nth-child(2) { border-right: 0; }
  .topic-card:nth-child(-n+2) { border-bottom: 1px solid var(--xy-border); }
}
@media (max-width: 767px) {
  .home-page .header-inner { height: 480px !important; min-height: 0; max-height: none; }
  .hero-container { padding: 80px 24px 40px; }
  .hero-eyebrow { font-size: .7rem; }
  .hero-description { max-width: 340px; font-size: .8rem; }
  .hero-intro { max-width: 325px; line-height: 1.65; }
  .hero-actions { margin-top: 20px; }
  .home-shell { padding-left: 20px; padding-right: 20px; }
  .home-page #board { padding-top: 30px; }
  .home-section { margin-bottom: 32px; }
  .section-heading { gap: 10px; margin-bottom: 16px; }
  .section-heading h2 { font-size: 1.2rem; }
  .section-heading > a { font-size: .7rem; }
  .featured-grid { grid-template-columns: 1fr; gap: 12px; }
  .featured-card { padding: 19px 20px 16px; }
  .featured-card .card-topline { margin-bottom: 8px; }
  .featured-card h3 { margin-bottom: 7px; }
  .featured-card p { margin-bottom: 12px; }
  .card-number { font-size: 1rem; }
  .topic-card { padding: 19px 16px; }
  .topic-card h3 { font-size: 1rem; }
  .topic-card p { font-size: .75rem; }
  .topic-label { font-size: .52rem; letter-spacing: .03em; }
  .recent-list { padding: 0 18px; }
  .recent-item { grid-template-columns: 1fr auto; gap: 4px 10px; padding: 18px 0; }
  .recent-item > time { grid-column: 1; }
  .recent-content { grid-column: 1 / -1; grid-row: 2; }
  .recent-category { grid-column: 2; grid-row: 1; margin-top: 0; }
  .recent-content h3 { font-size: .95rem; margin: 6px 0; }
  .series-note { display: block; padding-top: 18px; }
  .series-note > a { display: inline-block; margin-top: 10px; }
  .topic-directory { grid-template-columns: 1fr; gap: 16px; }
  .inner-page .header-inner { height: 260px !important; }
  .post-page .header-inner { height: 310px !important; }
  .banner-title { font-size: 1.5rem; }
  #board { border-radius: 10px; }
  .markdown-body { font-size: 15px; line-height: 1.95; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .01ms !important; transition-duration: .01ms !important; }
}
.learning-series { list-style: none; padding: 0; margin: 0; }
.learning-series li { border-bottom: 1px solid var(--xy-border); }
.learning-series li:last-child { border-bottom: 0; }
.learning-series a { display: grid; grid-template-columns: 34px minmax(0, 1fr) 20px; gap: 15px; align-items: center; padding: 19px 0; }
.series-number { color: var(--xy-accent); font-size: .8rem; font-variant-numeric: tabular-nums; }
.learning-series h3 { font-size: 1rem; margin: 0 0 4px; }
.learning-series p { font-size: .8rem; color: var(--xy-muted); margin: 0; }
.learning-series a > span:last-child { color: var(--xy-accent); }
.about-avatar { width: 96px; height: 96px; margin: -5.5rem auto 1.25rem; }
.about-avatar img { border: 4px solid var(--board-bg-color); box-shadow: 0 3px 12px #12283415; }
.project-showcase { display: grid; grid-template-columns: 1.1fr 1fr; background: var(--board-bg-color); border: 1px solid var(--xy-border); border-radius: 10px; overflow: hidden; }
.project-preview { display: block; overflow: hidden; background: #f4f4ef; }
.project-preview img { width: 100%; height: 100%; min-height: 280px; object-fit: cover; object-position: top center; }
.project-copy { align-self: center; padding: 32px; }
.project-copy h3 { font-size: 1.8rem; font-weight: 650; margin: 8px 0 15px; }
.project-copy > p:not(.section-kicker) { color: var(--xy-muted); font-size: .87rem; line-height: 1.95; }
.project-visit { display: inline-block; background: var(--xy-accent); color: var(--board-bg-color); border-radius: 4px; padding: 9px 17px; margin: 8px 15px 0 0; font-size: .8rem; }
.project-visit:hover { opacity: .9; color: var(--board-bg-color); }
.project-detail { font-size: .8rem; color: var(--xy-accent); }
@media (max-width: 767px) { .project-showcase { grid-template-columns: 1fr; } .project-copy { padding: 24px; } .project-preview img { min-height: 0; aspect-ratio: 16/9; } }