/* ===== M3 DESIGN TOKENS — Library Theme ===== */
:root {
  /* M3 Tonal Palette — Warm Sage/Teal for library */
  --md-primary: #3a6a5b;
  --md-on-primary: #ffffff;
  --md-primary-container: #bdf0de;
  --md-on-primary-container: #00201a;
  --md-secondary: #4d6357;
  --md-on-secondary: #ffffff;
  --md-secondary-container: #d0e8d8;
  --md-on-secondary-container: #0b1f16;
  --md-tertiary: #3f6373;
  --md-on-tertiary: #ffffff;
  --md-tertiary-container: #c2e8fb;
  --md-on-tertiary-container: #001f29;
  --md-surface: #f8faf6;
  --md-surface-dim: #d8dbd6;
  --md-surface-bright: #f8faf6;
  --md-surface-container-lowest: #ffffff;
  --md-surface-container-low: #f2f5f0;
  --md-surface-container: #ecefea;
  --md-surface-container-high: #e6e9e4;
  --md-surface-container-highest: #e1e3de;
  --md-on-surface: #191d1a;
  --md-on-surface-variant: #404943;
  --md-outline: #707973;
  --md-outline-variant: #c0c9c1;
  --md-error: #ba1a1a;
  --md-shadow: rgba(0,0,0,0.08);

  /* Semantic */
  --bg: var(--md-surface);
  --card: var(--md-surface-container-lowest);
  --card-hover: var(--md-surface-container-low);
  --text: var(--md-on-surface);
  --text-secondary: var(--md-on-surface-variant);
  --text-dim: var(--md-outline);
  --accent: var(--md-primary);
  --accent-container: var(--md-primary-container);
  --border: var(--md-outline-variant);

  /* Spacing & Shape */
  --radius-xl: 28px;
  --radius-lg: 16px;
  --radius-md: 12px;
  --radius-sm: 8px;
  --transition: 0.25s cubic-bezier(0.2,0,0,1);
}

/* ===== RESET ===== */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  font-family:'Inter',system-ui,-apple-system,sans-serif;
  background:var(--bg);
  color:var(--text);
  line-height:1.6;
  min-height:100vh;
}

/* ===== HERO ===== */
.hero{
  padding:56px 24px 44px;
  text-align:center;
  background:linear-gradient(180deg,var(--md-primary-container) 0%,var(--md-surface) 100%);
  position:relative;
}
.hero::after{
  content:'';position:absolute;bottom:0;left:0;right:0;height:1px;
  background:var(--md-outline-variant);
}
.hero-content{max-width:680px;margin:0 auto}
.hero-badge{
  display:inline-flex;align-items:center;gap:6px;
  padding:6px 16px;
  background:var(--md-surface-container-lowest);
  border:1px solid var(--md-outline-variant);
  border-radius:40px;
  font-size:13px;font-weight:500;
  color:var(--md-primary);
  margin-bottom:20px;
  box-shadow:0 1px 3px var(--md-shadow);
}
.hero h1{
  font-family:'Playfair Display','Georgia',serif;
  font-size:clamp(1.8rem,4.5vw,2.8rem);
  font-weight:700;
  color:var(--md-on-primary-container);
  margin-bottom:10px;
}
.hero-subtitle{font-size:1rem;color:var(--text-secondary);margin-bottom:28px}
.hero-subtitle strong{color:var(--md-primary);font-weight:600}

/* Search Bar — M3 Filled */
.search-bar{position:relative;max-width:520px;margin:0 auto}
.search-bar input{
  width:100%;padding:14px 44px 14px 48px;
  background:var(--md-surface-container-highest);
  border:none;
  border-radius:28px;
  font-size:0.95rem;color:var(--text);
  outline:none;transition:var(--transition);
}
.search-bar input:focus{
  background:var(--md-surface-container-lowest);
  box-shadow:0 2px 8px var(--md-shadow),0 0 0 2px var(--md-primary);
}
.search-bar input::placeholder{color:var(--text-dim)}
.search-icon{position:absolute;left:16px;top:50%;transform:translateY(-50%);width:20px;height:20px;color:var(--text-dim);pointer-events:none}
.clear-btn{position:absolute;right:14px;top:50%;transform:translateY(-50%);background:none;border:none;color:var(--text-dim);cursor:pointer;font-size:15px;padding:4px 8px;border-radius:50%}
.clear-btn:hover{background:var(--md-surface-container-high)}

/* ===== STATS BAR ===== */
.stats-bar{
  display:flex;justify-content:center;gap:10px;
  padding:20px 24px;flex-wrap:wrap;
  background:var(--md-surface-container-lowest);
  border-bottom:1px solid var(--md-outline-variant);
}
.stat-item{
  display:flex;flex-direction:column;align-items:center;
  padding:14px 24px;
  background:var(--md-surface-container-low);
  border-radius:var(--radius-lg);
  min-width:110px;
  transition:var(--transition);
}
.stat-item:hover{background:var(--md-primary-container);transform:translateY(-2px);box-shadow:0 4px 12px var(--md-shadow)}
.stat-number{font-size:1.5rem;font-weight:700;color:var(--md-primary);line-height:1.2}
.stat-label{font-size:0.7rem;color:var(--text-dim);text-transform:uppercase;letter-spacing:1px;margin-top:3px}

/* ===== FILTER NAV — M3 Chips ===== */
.filter-nav{
  display:flex;justify-content:center;gap:8px;
  padding:14px 24px;flex-wrap:wrap;
  position:sticky;top:0;z-index:100;
  background:rgba(248,250,246,0.92);
  backdrop-filter:blur(16px);
  border-bottom:1px solid var(--md-outline-variant);
}
.filter-tab{
  padding:8px 20px;
  border:1px solid var(--md-outline-variant);
  border-radius:20px;
  background:transparent;
  color:var(--text-secondary);
  font-size:0.88rem;font-weight:500;
  cursor:pointer;
  transition:var(--transition);
  white-space:nowrap;
}
.filter-tab:hover{background:var(--md-surface-container-high);border-color:var(--md-outline)}
.filter-tab.active{
  background:var(--md-secondary-container);
  border-color:transparent;
  color:var(--md-on-secondary-container);
  font-weight:600;
}

/* ===== MAIN CONTENT ===== */
.main-content{max-width:1100px;margin:0 auto;padding:28px 24px 60px}
.view{display:none;animation:fadeUp .35s ease}
.view.active{display:block}
@keyframes fadeUp{from{opacity:0;transform:translateY(12px)}to{opacity:1;transform:none}}
.section-title{
  font-size:1.35rem;font-weight:700;
  margin-bottom:20px;
  display:flex;align-items:center;gap:10px;
  color:var(--md-on-surface);
}
.badge{
  font-size:0.72rem;padding:4px 12px;
  background:var(--md-secondary-container);
  color:var(--md-on-secondary-container);
  border-radius:16px;font-weight:500;
}

/* ===== COLLECTION CARDS — M3 Filled Cards ===== */
.card-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:16px}
.collection-card{
  background:var(--card);
  border:1px solid var(--md-outline-variant);
  border-radius:var(--radius-lg);
  padding:24px 22px;
  cursor:pointer;
  transition:var(--transition);
  position:relative;
  overflow:hidden;
}
.collection-card::before{
  content:'';position:absolute;top:0;left:0;right:0;height:4px;
  background:var(--card-accent,var(--md-primary));
  border-radius:var(--radius-lg) var(--radius-lg) 0 0;
}
.collection-card:hover{
  transform:translateY(-3px);
  box-shadow:0 6px 24px var(--md-shadow),0 2px 8px var(--md-shadow);
  border-color:var(--card-accent,var(--md-primary));
}
.collection-card .card-icon{font-size:2.2rem;margin-bottom:10px}
.collection-card .card-code{
  font-size:0.72rem;font-weight:600;
  color:var(--card-accent,var(--md-primary));
  text-transform:uppercase;letter-spacing:2px;margin-bottom:3px;
}
.collection-card .card-name{font-size:1.05rem;font-weight:600;margin-bottom:6px;color:var(--text)}
.collection-card .card-count{font-size:1.8rem;font-weight:800;color:var(--card-accent,var(--md-primary))}
.collection-card .card-count span{font-size:0.8rem;font-weight:400;color:var(--text-dim);margin-left:4px}
.collection-card .card-loan{font-size:0.78rem;color:var(--text-dim);margin-top:6px}
.collection-card .card-loan strong{color:var(--text-secondary)}

/* ===== DDC — M3 List Items ===== */
.ddc-container{display:flex;flex-direction:column;gap:8px}
.ddc-row{
  display:flex;align-items:center;gap:14px;
  padding:16px 20px;
  background:var(--card);
  border:1px solid var(--md-outline-variant);
  border-radius:var(--radius-md);
  cursor:pointer;
  transition:var(--transition);
}
.ddc-row:hover{
  background:var(--md-surface-container-low);
  border-color:var(--md-primary);
  box-shadow:0 2px 12px var(--md-shadow);
  transform:translateX(3px);
}
.ddc-num{
  font-size:1.2rem;font-weight:800;
  color:var(--ddc-color,var(--md-primary));
  min-width:56px;text-align:center;
  background:var(--md-surface-container-high);
  padding:6px 0;border-radius:var(--radius-sm);
}
.ddc-name{flex:1;font-weight:500;font-size:0.95rem;color:var(--text)}
.ddc-name-vi{font-size:0.8rem;color:var(--text-dim);margin-top:2px}
.ddc-bar-wrap{flex:0 0 180px;height:6px;background:var(--md-surface-container-high);border-radius:10px;overflow:hidden}
.ddc-bar{height:100%;border-radius:10px;transition:width 1s ease}
.ddc-count{font-size:0.88rem;font-weight:600;color:var(--text-secondary);min-width:46px;text-align:right}

/* ===== SUBJECTS — M3 Cards ===== */
.subjects-container{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:12px}
.subject-card{
  padding:16px;
  background:var(--card);
  border:1px solid var(--md-outline-variant);
  border-radius:var(--radius-md);
  cursor:pointer;
  transition:var(--transition);
  display:flex;align-items:center;gap:12px;
}
.subject-card:hover{
  background:var(--md-primary-container);
  border-color:var(--md-primary);
  box-shadow:0 2px 10px var(--md-shadow);
  transform:translateY(-2px);
}
.subject-icon{
  font-size:1.4rem;width:44px;height:44px;
  display:flex;align-items:center;justify-content:center;
  background:var(--md-surface-container-high);
  border-radius:var(--radius-md);flex-shrink:0;
}
.subject-card:hover .subject-icon{background:var(--md-on-primary-container);filter:brightness(1.2)}
.subject-info{flex:1}
.subject-name{font-weight:600;font-size:0.9rem;color:var(--text)}
.subject-meta{font-size:0.76rem;color:var(--text-dim);margin-top:2px}

/* ===== TAG CLOUD ===== */
.tag-cloud{display:flex;flex-wrap:wrap;gap:8px;justify-content:center;padding:16px 0}
.tag{
  padding:7px 16px;
  border-radius:20px;font-size:0.84rem;font-weight:500;
  cursor:pointer;transition:var(--transition);
  border:1px solid var(--md-outline-variant);
  background:var(--card);
  color:var(--text-secondary);
}
.tag:hover{
  background:var(--md-primary-container);
  border-color:var(--md-primary);
  color:var(--md-on-primary-container);
  transform:scale(1.06);
  box-shadow:0 2px 8px var(--md-shadow);
}
.tag.size-lg{font-size:1.05rem;padding:9px 22px;font-weight:600;background:var(--md-secondary-container);border-color:transparent;color:var(--md-on-secondary-container)}
.tag.size-md{font-size:0.92rem;padding:8px 18px}

/* ===== RESULTS PANEL ===== */
.results-panel{
  margin-top:28px;
  background:var(--card);
  border:1px solid var(--md-outline-variant);
  border-radius:var(--radius-lg);
  overflow:hidden;
  animation:fadeUp .3s ease;
  box-shadow:0 2px 12px var(--md-shadow);
}
.results-header{
  display:flex;justify-content:space-between;align-items:center;
  padding:18px 22px;
  border-bottom:1px solid var(--md-outline-variant);
  background:var(--md-surface-container-low);
}
.results-header h3{font-size:1.05rem;font-weight:600;color:var(--text)}
.close-btn{
  background:none;border:1px solid var(--md-outline-variant);
  border-radius:20px;color:var(--text-secondary);
  padding:5px 14px;cursor:pointer;font-size:0.82rem;
  transition:var(--transition);
}
.close-btn:hover{border-color:var(--md-error);color:var(--md-error);background:rgba(186,26,26,0.05)}
.results-list{max-height:480px;overflow-y:auto;padding:6px 0}
.result-item{
  display:flex;align-items:flex-start;gap:12px;
  padding:12px 22px;
  border-bottom:1px solid var(--md-surface-container-high);
  transition:var(--transition);
}
.result-item:last-child{border-bottom:none}
.result-item:hover{background:var(--md-surface-container-low)}
.result-num{font-size:0.72rem;color:var(--text-dim);min-width:26px;padding-top:3px;text-align:right;font-weight:600}
.result-info{flex:1}
.result-title{font-weight:600;font-size:0.92rem;margin-bottom:3px;color:var(--text)}
.result-meta{font-size:0.78rem;color:var(--text-dim)}
.result-meta span{margin-right:12px}
.result-ddc{
  padding:3px 10px;
  background:var(--md-tertiary-container);
  color:var(--md-on-tertiary-container);
  border-radius:6px;font-size:0.76rem;font-weight:600;white-space:nowrap;
}
.no-results{padding:36px;text-align:center;color:var(--text-dim);font-size:0.92rem}
.no-results a{color:var(--md-primary);text-decoration:none;font-weight:500}
.no-results a:hover{text-decoration:underline}

/* ===== FOOTER ===== */
.site-footer{
  text-align:center;padding:36px 24px 28px;
  border-top:1px solid var(--md-outline-variant);
  color:var(--text-dim);font-size:0.82rem;
  background:var(--md-surface-container-low);
}
.footer-sub{font-size:0.72rem;margin-top:5px;opacity:0.7}

/* ===== SCROLLBAR ===== */
::-webkit-scrollbar{width:5px}
::-webkit-scrollbar-track{background:transparent}
::-webkit-scrollbar-thumb{background:var(--md-outline-variant);border-radius:3px}

/* ===== RESPONSIVE ===== */
@media(max-width:768px){
  .hero{padding:36px 16px 28px}
  .stats-bar{gap:6px}
  .stat-item{padding:10px 14px;min-width:70px}
  .stat-number{font-size:1.15rem}
  .filter-nav{gap:6px;padding:10px 16px}
  .filter-tab{padding:7px 14px;font-size:0.8rem}
  .main-content{padding:18px 16px 36px}
  .card-grid{grid-template-columns:1fr}
  .ddc-bar-wrap{display:none}
  .subjects-container{grid-template-columns:1fr 1fr}
}
@media(max-width:480px){
  .subjects-container{grid-template-columns:1fr}
  .ddc-row{flex-wrap:wrap;gap:6px}
}