:root{
  --lib-green:#1e3a2b;
  --lib-green-dark:#122318;
  --lib-green-soft:#2c4d3a;
  --parchment:#f6f1e4;
  --card-cream:#fbf8f0;
  --sage:#e3e8da;
  --gold:#a9812f;
  --gold-bright:#c9a24b;
  --ink:#241f18;
  --ink-soft:#544c3f;
  --serif:'Noto Serif Thai', serif;
  --sans:'Noto Sans Thai', sans-serif;
}

*{box-sizing:border-box;}
html{scroll-behavior:smooth;}
body{
  font-family:var(--sans);
  color:var(--ink);
  background:var(--parchment);
  background-image:
    radial-gradient(circle at 100% 0%, rgba(169,129,47,0.06), transparent 45%),
    radial-gradient(circle at 0% 100%, rgba(30,58,43,0.05), transparent 40%);
}
::selection{background:var(--gold-bright);color:var(--lib-green-dark);}

h1,h2,h3,h4,.font-serif{font-family:var(--serif);}

a{text-decoration:none;}

/* ---------- Utility: catalog eyebrow (Dewey-style code) ---------- */
.catalog-code{
  display:inline-flex;
  align-items:center;
  gap:.5rem;
  font-family:var(--sans);
  font-weight:700;
  letter-spacing:.14em;
  font-size:.72rem;
  color:var(--gold);
  text-transform:uppercase;
  border:1px solid var(--gold);
  border-radius:2px;
  padding:.25rem .65rem;
}
.catalog-code .num{
  font-family:var(--serif);
  font-size:.95rem;
  letter-spacing:0;
}

/* ---------- Navbar ---------- */
.navbar-library{
  background:var(--lib-green);
  padding-top:.65rem;
  padding-bottom:.65rem;
  transition:box-shadow .3s ease, padding .3s ease, background .3s ease;
  border-bottom:3px solid var(--gold);
}
.navbar-library.scrolled{
  padding-top:.35rem;
  padding-bottom:.35rem;
  box-shadow:0 8px 24px rgba(0,0,0,.25);
  background:var(--lib-green-dark);
}
.navbar-brand-lib{
  font-family:var(--serif);
  font-weight:700;
  color:var(--parchment)!important;
  font-size:1.35rem;
  display:flex;
  align-items:center;
  gap:.6rem;
}
.navbar-brand-lib .brand-mark{
  width:38px;height:38px;
  display:inline-flex;align-items:center;justify-content:center;
  border:1.5px solid var(--gold-bright);
  border-radius:50%;
  color:var(--gold-bright);
  font-size:1.1rem;
}
.navbar-brand-lib small{
  display:block;
  font-family:var(--sans);
  font-size:.62rem;
  letter-spacing:.16em;
  color:var(--sage);
  font-weight:400;
  text-transform:uppercase;
}
.navbar-library .nav-link{
  color:var(--sage)!important;
  font-weight:600;
  letter-spacing:.02em;
  padding:.55rem 1rem!important;
  position:relative;
}
.navbar-library .nav-link::after{
  content:"";
  position:absolute;
  left:1rem;right:1rem;bottom:.3rem;
  height:2px;background:var(--gold-bright);
  transform:scaleX(0);
  transform-origin:left;
  transition:transform .25s ease;
}
.navbar-library .nav-link:hover::after,
.navbar-library .nav-link.active::after{transform:scaleX(1);}
.navbar-library .nav-link.active{color:var(--gold-bright)!important;}
.btn-search-lib{
  border:1.5px solid var(--gold-bright);
  color:var(--gold-bright);
  border-radius:2px;
  font-weight:600;
  font-size:.85rem;
}
.btn-search-lib:hover{background:var(--gold-bright);color:var(--lib-green-dark);}

/* ---------- Hero Carousel (หน้าแรก) ---------- */
#heroCarousel{margin-top:0;}
.hero-slide{
  height:78vh;
  min-height:460px;
  position:relative;
  display:flex;
  align-items:flex-end;
  overflow:hidden;
}
.hero-slide::before{
  content:"";
  position:absolute;inset:0;
  background:
    linear-gradient(180deg, rgba(18,35,24,.25) 0%, rgba(18,35,24,.55) 60%, rgba(18,35,24,.92) 100%);
  z-index:1;
}
.hero-slide .shelf-pattern{
  position:absolute;inset:0;
  opacity:.55;
  background-size:cover;
  background-position:center;
}
.slide-a .shelf-pattern{background-color:#1c3f2c;}
.slide-b .shelf-pattern{background-color:#3a2f1c;}
.slide-c .shelf-pattern{background-color:#26364a;}

.hero-caption{
  position:relative;z-index:2;
  color:var(--parchment);
  padding:3rem 0 4rem;
}
.hero-stamp{
  display:inline-block;
  border:2px solid var(--gold-bright);
  color:var(--gold-bright);
  padding:.2rem .8rem;
  font-size:.72rem;
  letter-spacing:.18em;
  font-weight:700;
  text-transform:uppercase;
  border-radius:2px;
  margin-bottom:1rem;
  transform:rotate(-2deg);
}
.hero-caption h2{
  font-size:clamp(1.8rem, 4vw, 3.1rem);
  font-weight:700;
  max-width:820px;
  line-height:1.25;
}
.hero-caption p{
  max-width:620px;
  color:var(--sage);
  font-size:1.05rem;
}
.carousel-control-prev,.carousel-control-next{width:5%;}
.carousel-indicators [data-bs-target]{
  background-color:var(--gold-bright);
  width:34px;height:3px;
}

/* ---------- Page header (สำหรับหน้าเมนูย่อย) ---------- */
.page-header{
  background:var(--lib-green);
  color:var(--parchment);
  padding:3.2rem 0 2.4rem;
  position:relative;
  overflow:hidden;
  border-bottom:4px solid var(--gold);
}
.page-header::before{
  content:"";
  position:absolute;inset:0;
  background:repeating-linear-gradient(115deg, rgba(169,129,47,.10) 0 10px, transparent 10px 26px);
}
.page-header .container{position:relative;z-index:1;}
.page-header h1{
  font-weight:700;
  font-size:clamp(1.7rem, 3.4vw, 2.6rem);
  margin:.6rem 0 .5rem;
}
.page-header p{color:var(--sage);max-width:640px;margin:0;}
.breadcrumb-lib{
  font-size:.85rem;
  color:var(--sage);
}
.breadcrumb-lib a{color:var(--gold-bright);}

/* ---------- Section headings ---------- */
.section-pad{padding:5rem 0;}
.section-head{
  display:flex;
  align-items:flex-end;
  justify-content:space-between;
  flex-wrap:wrap;
  gap:1rem;
  margin-bottom:2.5rem;
  border-bottom:2px solid var(--sage);
  padding-bottom:1.25rem;
}
.section-head h2{
  font-size:2rem;
  font-weight:700;
  color:var(--lib-green);
  margin:0;
}
.section-head .lead-note{color:var(--ink-soft);font-size:.95rem;margin:0;max-width:460px;}

.section-alt{background:var(--card-cream);}

/* ---------- News cards (bulletin board) ---------- */
.news-card{
  background:var(--card-cream);
  border:1px solid var(--sage);
  border-left:4px solid var(--gold);
  border-radius:4px;
  padding:1.6rem;
  height:100%;
  transition:transform .25s ease, box-shadow .25s ease, border-color .25s ease;
}
.news-card:hover{
  transform:translateY(-6px);
  box-shadow:0 16px 28px rgba(30,58,43,.12);
  border-left-color:var(--gold-bright);
}
.news-card .date-tag{
  font-size:.78rem;
  color:var(--gold);
  font-weight:700;
  letter-spacing:.04em;
  display:flex;align-items:center;gap:.4rem;
  margin-bottom:.7rem;
}
.news-card h5{
  font-family:var(--serif);
  color:var(--lib-green);
  font-weight:600;
  margin-bottom:.6rem;
}
.news-card p{color:var(--ink-soft);font-size:.92rem;margin-bottom:.9rem;}
.news-card .read-more{
  font-weight:700;font-size:.85rem;color:var(--lib-green);
  display:inline-flex;align-items:center;gap:.35rem;
  border:none;background:none;padding:0;
}
.news-card .read-more i{transition:transform .2s ease;}
.news-card .read-more:hover i{transform:translateX(4px);}

/* ---------- Gallery ---------- */
.filter-pill{
  border:1.5px solid var(--sage);
  background:var(--card-cream);
  color:var(--ink-soft);
  border-radius:30px;
  padding:.4rem 1.1rem;
  font-size:.85rem;
  font-weight:600;
  transition:all .2s ease;
}
.filter-pill:hover{border-color:var(--gold);color:var(--lib-green);}
.filter-pill.active{background:var(--lib-green);border-color:var(--lib-green);color:var(--parchment);}

.gallery-tile{
  position:relative;
  border-radius:6px;
  overflow:hidden;
  aspect-ratio:4/3;
  cursor:pointer;
  background:var(--lib-green-soft);
}
.gallery-tile img{
  width:100%;height:100%;object-fit:cover;
  transition:transform .5s ease;
  display:block;
}
.gallery-tile:hover img{transform:scale(1.08);}
.gallery-tile .tile-overlay{
  position:absolute;inset:0;
  background:linear-gradient(0deg, rgba(18,35,24,.88) 0%, rgba(18,35,24,0) 55%);
  display:flex;align-items:flex-end;
  padding:1rem;
  opacity:0;
  transition:opacity .3s ease;
}
.gallery-tile:hover .tile-overlay{opacity:1;}
.tile-overlay span{color:var(--parchment);font-weight:600;font-size:.9rem;}
.tile-overlay i{color:var(--gold-bright);margin-left:auto;}

/* ---------- Exhibition ---------- */
.exhibit-feature{
  background:var(--lib-green);
  color:var(--parchment);
  border-radius:8px;
  overflow:hidden;
  position:relative;
}
.exhibit-feature .feature-art{
  min-height:280px;
  background:
    repeating-linear-gradient(115deg, rgba(169,129,47,.18) 0 10px, transparent 10px 26px),
    linear-gradient(160deg, #24462f, #17281c);
  position:relative;
}
.exhibit-feature .feature-body{padding:2.2rem;}
.exhibit-feature h3{font-weight:700;font-size:1.6rem;margin-bottom:.8rem;}
.exhibit-feature p{color:var(--sage);}
.exhibit-feature .catalog-code{border-color:var(--gold-bright);color:var(--gold-bright);}

.exhibit-list-item{
  display:flex;
  gap:1.1rem;
  padding:1.1rem 0;
  border-bottom:1px solid var(--sage);
  align-items:flex-start;
}
.exhibit-list-item:last-child{border-bottom:none;}
.exhibit-list-item .num-block{
  font-family:var(--serif);
  font-weight:700;
  color:var(--gold);
  font-size:1.4rem;
  min-width:70px;
  border-right:2px solid var(--sage);
  padding-right:1rem;
  line-height:1.1;
}
.exhibit-list-item .num-block small{
  display:block;font-family:var(--sans);
  font-size:.65rem;letter-spacing:.08em;
  color:var(--ink-soft);font-weight:600;
  margin-top:.15rem;
}
.exhibit-list-item h6{
  font-family:var(--serif);color:var(--lib-green);
  font-weight:600;margin-bottom:.2rem;
}
.exhibit-list-item p{color:var(--ink-soft);font-size:.88rem;margin:0;}

.exhibit-past-card{
  background:var(--card-cream);
  border:1px solid var(--sage);
  border-radius:6px;
  padding:1.4rem;
  height:100%;
}
.exhibit-past-card .catalog-code{font-size:.65rem;margin-bottom:.7rem;}
.exhibit-past-card h6{font-family:var(--serif);color:var(--lib-green);font-weight:600;}
.exhibit-past-card p{color:var(--ink-soft);font-size:.85rem;margin-bottom:0;}

/* ---------- Document / file archive cards ---------- */
.doc-card{
  display:flex;
  align-items:center;
  gap:1rem;
  background:var(--card-cream);
  border:1px solid var(--sage);
  border-radius:6px;
  padding:1.2rem 1.4rem;
  height:100%;
  transition:transform .25s ease, box-shadow .25s ease, border-color .25s ease;
}
.doc-card:hover{
  transform:translateY(-4px);
  box-shadow:0 14px 24px rgba(30,58,43,.10);
  border-color:var(--gold);
}
.doc-card .doc-icon{
  width:52px;height:52px;
  min-width:52px;
  border-radius:6px;
  background:var(--lib-green);
  color:var(--gold-bright);
  display:flex;align-items:center;justify-content:center;
  font-size:1.4rem;
}
.doc-card .doc-info h6{
  font-family:var(--serif);
  color:var(--lib-green);
  font-weight:600;
  margin-bottom:.2rem;
}
.doc-card .doc-info .doc-meta{
  font-size:.78rem;
  color:var(--ink-soft);
}
.doc-card .doc-download{
  margin-left:auto;
  width:38px;height:38px;
  border-radius:50%;
  border:1.5px solid var(--gold);
  color:var(--gold);
  display:flex;align-items:center;justify-content:center;
  flex-shrink:0;
  transition:all .2s ease;
}
.doc-card .doc-download:hover{background:var(--gold);color:var(--card-cream);}

.image-download-tile{
  position:relative;
  border-radius:6px;
  overflow:hidden;
  aspect-ratio:4/3;
}
.image-download-tile img{width:100%;height:100%;object-fit:cover;display:block;}
.image-download-tile .dl-btn{
  position:absolute;
  right:.6rem;bottom:.6rem;
  width:36px;height:36px;
  border-radius:50%;
  background:rgba(18,35,24,.75);
  color:var(--parchment);
  display:flex;align-items:center;justify-content:center;
  transition:background .2s ease;
}
.image-download-tile .dl-btn:hover{background:var(--gold-bright);color:var(--lib-green-dark);}

/* ---------- Shelf divider ---------- */
.shelf-divider{
  height:14px;
  background:repeating-linear-gradient(90deg, var(--gold) 0 6px, var(--gold-bright) 6px 9px, var(--lib-green) 9px 46px);
  opacity:.85;
}

/* ---------- Footer ---------- */
footer{
  background:var(--lib-green-dark);
  color:var(--sage);
  padding:3.5rem 0 1.5rem;
}
footer h6{
  font-family:var(--serif);
  color:var(--gold-bright);
  font-weight:700;
  margin-bottom:1rem;
}
footer a{color:var(--sage);}
footer a:hover{color:var(--gold-bright);}
footer .foot-bottom{
  border-top:1px solid rgba(255,255,255,.12);
  margin-top:2.5rem;
  padding-top:1.25rem;
  font-size:.82rem;
  color:#9fae9f;
}
.social-btn{
  width:36px;height:36px;
  border:1px solid rgba(255,255,255,.25);
  border-radius:50%;
  display:inline-flex;align-items:center;justify-content:center;
  color:var(--sage);
  margin-right:.5rem;
  transition:all .2s ease;
}
.social-btn:hover{background:var(--gold-bright);border-color:var(--gold-bright);color:var(--lib-green-dark);}

/* ---------- Back to top ---------- */
#backToTop{
  position:fixed;
  right:1.4rem;bottom:1.4rem;
  width:46px;height:46px;
  border-radius:50%;
  background:var(--gold-bright);
  color:var(--lib-green-dark);
  display:flex;align-items:center;justify-content:center;
  font-size:1.2rem;
  box-shadow:0 8px 20px rgba(0,0,0,.25);
  opacity:0;visibility:hidden;
  transform:translateY(10px);
  transition:all .3s ease;
  z-index:1050;
  border:none;
}
#backToTop.show{opacity:1;visibility:visible;transform:translateY(0);}

@media (prefers-reduced-motion: reduce){
  html{scroll-behavior:auto;}
  *{transition:none!important;animation:none!important;}
}

@media (max-width: 767.98px){
  .hero-slide{height:70vh;min-height:420px;}
  .section-pad{padding:3.2rem 0;}
  .exhibit-list-item .num-block{min-width:56px;font-size:1.1rem;}
  .page-header{padding:2.4rem 0 1.8rem;}
}