/* ============================================================
   DuyTom Joomla Template — template.css
   Editorial Ink Design System
   Fonts: Playfair Display (headings) + Inter (body)
   Colors: Navy #0D47A1, Warm White #FAFAF8, Near-black #0D1B3E
   ============================================================ */

/* ── Google Fonts are loaded via index.php ── */

/* ── CSS Reset & Base ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --dt-navy:       #0D47A1;
  --dt-navy-dark:  #0D1B3E;
  --dt-navy-mid:   #1565C0;
  --dt-teal:       #0E7490;
  --dt-amber:      #B45309;
  --dt-bg:         #FAFAF8;
  --dt-white:      #FFFFFF;
  --dt-text:       #1A1A2E;
  --dt-text-muted: #4B5563;
  --dt-text-light: #6B7280;
  --dt-border:     #E2E8F0;
  --dt-shadow-sm:  0 1px 4px rgba(13,71,161,.06);
  --dt-shadow-md:  0 4px 16px rgba(13,71,161,.10);
  --dt-shadow-lg:  0 12px 32px rgba(13,71,161,.14);
  --dt-radius:     0.5rem;
  --dt-font-serif: 'Playfair Display', Georgia, 'Times New Roman', serif;
  --dt-font-sans:  'Inter', system-ui, -apple-system, Arial, sans-serif;
  --dt-max-width:  1060px;
  --dt-ease:       cubic-bezier(0.23, 1, 0.32, 1);
}

html { font-size: 15px; scroll-behavior: smooth; }

body {
  font-family: var(--dt-font-sans);
  font-size: 1rem;
  line-height: 1.65;
  color: var(--dt-text);
  background: var(--dt-bg);
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--dt-font-serif);
  line-height: 1.25;
  letter-spacing: -0.01em;
  color: var(--dt-navy-dark);
}

a {
  color: var(--dt-navy);
  text-decoration: none;
  transition: color 0.15s ease;
}
a:hover { color: var(--dt-navy-mid); }

img { display: block; max-width: 100%; height: auto; }

/* ── Container ── */
.dt-container {
  width: 100%;
  max-width: var(--dt-max-width);
  margin: 0 auto;
  padding: 0 1rem;
}
@media (min-width: 640px)  { .dt-container { padding: 0 1.5rem; } }
@media (min-width: 1080px) { .dt-container { padding: 0 2rem; } }

/* ══════════════════════════════════════════
   HEADER
══════════════════════════════════════════ */
.dt-header {
  background: var(--dt-white);
  position: sticky;
  top: 0;
  z-index: 100;
  transition: box-shadow 0.2s ease;
}
.dt-header.scrolled {
  box-shadow: 0 2px 20px rgba(13,71,161,.10);
}

.dt-accent-bar {
  height: 3px;
  background: linear-gradient(90deg, #0D47A1, #1976D2, #0E7490);
}

.dt-header-inner {
  max-width: var(--dt-max-width);
  margin: 0 auto;
  padding: 0 1rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
  gap: 1rem;
}
@media (min-width: 640px) { .dt-header-inner { padding: 0 1.5rem; } }

/* Brand / Masthead */
.dt-brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  flex-shrink: 0;
}
.dt-brand:hover { text-decoration: none; }
.dt-brand-logo {
  height: 48px;
  width: auto;
  transition: opacity 0.2s ease;
}
.dt-brand:hover .dt-brand-logo { opacity: 0.8; }
.dt-brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1;
}
.dt-brand-name {
  font-family: var(--dt-font-serif);
  font-size: 22px;
  font-weight: 800;
  color: var(--dt-navy-dark);
  letter-spacing: -0.02em;
}
.dt-brand-tagline {
  font-family: var(--dt-font-sans);
  font-size: 9px;
  font-weight: 600;
  color: var(--dt-navy);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  margin-top: 3px;
}
@media (max-width: 480px) { .dt-brand-text { display: none; } }

/* Desktop Nav */
.dt-nav { display: flex; align-items: center; gap: 2px; }

.dt-nav ul { list-style: none; display: flex; align-items: center; gap: 2px; }
.dt-nav ul li { position: relative; }
.dt-nav ul li a,
.dt-nav ul li span.separator { display: none; } /* hide Joomla separators */

.dt-nav ul li a {
  display: block;
  padding: 0.5rem 1rem;
  font-family: var(--dt-font-sans);
  font-size: 13px;
  font-weight: 600;
  color: #374151;
  letter-spacing: 0.01em;
  border-radius: 4px;
  transition: color 0.15s ease, background 0.15s ease;
  position: relative;
  text-decoration: none;
}
.dt-nav ul li a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 1rem;
  right: 1rem;
  height: 2px;
  background: var(--dt-navy);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.2s var(--dt-ease);
}
.dt-nav ul li a:hover,
.dt-nav ul li.active > a,
.dt-nav ul li.current > a {
  color: var(--dt-navy);
  background: #EEF2FF;
  text-decoration: none;
}
.dt-nav ul li.active > a::after,
.dt-nav ul li.current > a::after,
.dt-nav ul li a:hover::after {
  transform: scaleX(1);
}

/* Mobile toggle */
.dt-nav-toggle {
  display: none;
  background: none;
  border: none;
  padding: 0.5rem;
  cursor: pointer;
  color: #6B7280;
  border-radius: 6px;
  transition: background 0.15s ease, color 0.15s ease;
}
.dt-nav-toggle:hover { background: #EEF2FF; color: var(--dt-navy); }
.dt-hamburger { display: flex; flex-direction: column; gap: 5px; width: 22px; }
.dt-hamburger span {
  display: block;
  height: 2px;
  background: currentColor;
  border-radius: 2px;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

@media (max-width: 767px) {
  .dt-nav { display: none; }
  .dt-nav-toggle { display: flex; }
  .dt-nav.dt-nav-open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--dt-white);
    border-top: 1px solid var(--dt-border);
    padding: 0.75rem 1rem;
    gap: 2px;
    box-shadow: var(--dt-shadow-md);
  }
  .dt-nav.dt-nav-open ul { flex-direction: column; width: 100%; }
  .dt-nav.dt-nav-open ul li a {
    display: block;
    padding: 0.625rem 1rem;
    border-radius: 6px;
  }
  .dt-nav.dt-nav-open ul li a::after { display: none; }
}

/* ══════════════════════════════════════════
   MAIN LAYOUT
══════════════════════════════════════════ */
.dt-main { padding: 2rem 0 3rem; }

.dt-content-wrap { display: flex; gap: 2rem; }
.dt-content-main { flex: 1; min-width: 0; }
.dt-sidebar { width: 300px; flex-shrink: 0; }
.dt-no-sidebar .dt-content-main { width: 100%; }

@media (max-width: 900px) {
  .dt-content-wrap { flex-direction: column; }
  .dt-sidebar { width: 100%; }
}

/* Breadcrumb */
.dt-breadcrumb {
  margin-bottom: 1.5rem;
  font-size: 12px;
  color: var(--dt-text-light);
}
.dt-breadcrumb a { color: var(--dt-navy); }
.dt-breadcrumb .divider { margin: 0 0.4rem; color: #D1D5DB; }

/* ══════════════════════════════════════════
   SECTION LABELS
══════════════════════════════════════════ */
.dt-section-label {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1.25rem;
}
.dt-section-label span {
  font-family: var(--dt-font-sans);
  font-size: 10px;
  font-weight: 900;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--dt-navy);
  white-space: nowrap;
}
.dt-section-rule {
  flex: 1;
  height: 1px;
  background: rgba(13,71,161,.2);
}
.dt-section-label--grid { margin-top: 3rem; }

/* ══════════════════════════════════════════
   HERO FEATURED CARD
══════════════════════════════════════════ */
.dt-hero-card { margin-bottom: 1.25rem;position: relative; }
.dt-hero-link { display: block; text-decoration: none; }
.dt-hero-link:hover { text-decoration: none; }

.dt-hero-img-wrap {
  position: relative;
  aspect-ratio: 21/9;
  overflow: hidden;
  border-radius: 1rem;
  box-shadow: var(--dt-shadow-lg);
}
.dt-hero-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.7s var(--dt-ease);
}
.dt-hero-link:hover .dt-hero-img { transform: scale(1.03); }

.dt-hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(to top, rgba(13,27,62,.9) 0%, rgba(13,27,62,.3) 50%, transparent 100%);
  border-radius: 1rem;
  pointer-events: none;
}

.dt-hero-content {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  padding: 2rem 2.5rem;
}
@media (max-width: 640px) { .dt-hero-content { padding: 1.25rem 1.25rem; } }

.dt-hero-title {
  font-family: var(--dt-font-serif);
  font-size: clamp(20px, 3vw, 34px);
  font-weight: 700;
  color: white;
  line-height: 1.2;
  margin-bottom: 1rem;
  max-width: 680px;
  text-shadow: 0 2px 12px rgba(0,0,0,.4);
  transition: color 0.15s ease;
}
.dt-hero-link:hover .dt-hero-title { color: #BFDBFE; }

.dt-hero-meta {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}
.dt-hero-date {
  display: flex;
  align-items: center;
  gap: 6px;
  color: rgba(255,255,255,.65);
  font-size: 12px;
  font-weight: 500;
}
.dt-hero-readmore {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: white;
  font-size: 12px;
  font-weight: 700;
  background: rgba(255,255,255,.15);
  backdrop-filter: blur(4px);
  border: 1px solid rgba(255,255,255,.2);
  padding: 6px 16px;
  border-radius: 999px;
  transition: background 0.15s ease;
}
.dt-hero-link:hover .dt-hero-readmore { background: rgba(255,255,255,.25); }

.dt-hero-excerpt {
  font-family: var(--dt-font-sans);
  font-size: 14px;
  color: var(--dt-text-muted);
  line-height: 1.7;
  max-width: 680px;
  border-left: 3px solid rgba(13,71,161,.3);
  padding-left: 1rem;
  margin-top: 1.25rem;
}

/* ══════════════════════════════════════════
   ARTICLE GRID & CARDS
══════════════════════════════════════════ */
.dt-article-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}
@media (max-width: 900px)  { .dt-article-grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 560px)  { .dt-article-grid { grid-template-columns: 1fr; } }

.dt-article-card {
  background: var(--dt-white);
  border: 1px solid var(--dt-border);
  border-radius: var(--dt-radius);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: transform 0.2s var(--dt-ease), box-shadow 0.2s var(--dt-ease);
}
.dt-article-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--dt-shadow-lg);
}

.dt-card-img-link { display: block; text-decoration: none; }
.dt-card-img-wrap {
  aspect-ratio: 16/10;
  overflow: hidden;
}
.dt-card-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.35s var(--dt-ease);
}
.dt-article-card:hover .dt-card-img { transform: scale(1.04); }

.dt-card-body {
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  flex: 1;
  border-top: 1px solid var(--dt-border);
}

.dt-card-meta {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-bottom: 0.625rem;
}
.dt-card-date {
  display: flex;
  align-items: center;
  gap: 4px;
  font-size: 11px;
  color: var(--dt-text-light);
  font-weight: 500;
}

.dt-card-title {
  font-family: var(--dt-font-serif);
  font-size: 16px;
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 0.625rem;
  flex: 1;
}
.dt-card-title a {
  color: var(--dt-navy-dark);
  text-decoration: none;
  transition: color 0.15s ease;
}
.dt-card-title a:hover { color: var(--dt-navy); }

.dt-card-rule {
  width: 2rem;
  height: 2px;
  background: rgba(13,71,161,.3);
  margin-bottom: 0.75rem;
  flex-shrink: 0;
}

.dt-card-excerpt {
  font-size: 13px;
  color: var(--dt-text-muted);
  line-height: 1.65;
  margin-bottom: 1rem;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.dt-card-readmore {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  font-weight: 700;
  color: var(--dt-navy);
  text-decoration: none;
  margin-top: auto;
  transition: color 0.15s ease, gap 0.15s ease;
}
.dt-card-readmore:hover { color: var(--dt-navy-mid); gap: 10px; text-decoration: none; }

/* ══════════════════════════════════════════
   CATEGORY PAGE
══════════════════════════════════════════ */
.dt-category-page { }
.dt-category-banner {
  background: linear-gradient(135deg, #0D2E6B, #0D47A1);
  color: white;
  padding: 2.5rem 2rem;
  margin: -2rem -1rem 2rem;
}
@media (min-width: 640px) { .dt-category-banner { margin: -2rem -1.5rem 2rem; padding: 2.5rem 1.5rem; } }
@media (min-width: 1080px) { .dt-category-banner { margin: -2rem -2rem 2rem; padding: 2.5rem 2rem; } }

.dt-category-title {
  font-family: var(--dt-font-serif);
  font-size: 2rem;
  font-weight: 700;
  color: white;
  margin-bottom: 0.25rem;
}
.dt-category-desc { color: rgba(255,255,255,.75); font-size: 14px; margin-bottom: 0.25rem; }
.dt-category-count { color: rgba(255,255,255,.55); font-size: 13px; }

/* ══════════════════════════════════════════
   ARTICLE DETAIL PAGE
══════════════════════════════════════════ */
.dt-article-detail { max-width: 860px; }

.dt-article-title {
  font-family: var(--dt-font-serif);
  font-size: clamp(24px, 4vw, 38px);
  font-weight: 700;
  color: var(--dt-navy-dark);
  line-height: 1.2;
  margin: 0.75rem 0 1rem;
}

.dt-article-meta {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: 12px;
  color: var(--dt-text-light);
  padding-bottom: 1.25rem;
  border-bottom: 1px solid var(--dt-border);
  margin-bottom: 1.5rem;
}
.dt-article-date, .dt-article-author {
  display: flex;
  align-items: center;
  gap: 5px;
}

.dt-article-hero {
  border-radius: var(--dt-radius);
  overflow: hidden;
  box-shadow: var(--dt-shadow-md);
  margin-bottom: 2rem;
}
.dt-article-hero-img {
  width: 100%;
  max-height: 500px;
  object-fit: cover;
}

.dt-article-body {
  font-size: 15px;
  line-height: 1.8;
  color: var(--dt-text);
}
.dt-article-body p { margin-bottom: 1.25rem; }
.dt-article-body h2, .dt-article-body h3 { margin: 2rem 0 1rem; }
.dt-article-body img { border-radius: 6px; margin: 1.5rem 0; }
.dt-article-body a { color: var(--dt-navy); text-decoration: underline; }
.dt-article-body blockquote {
  border-left: 3px solid var(--dt-navy);
  padding: 0.75rem 1.25rem;
  margin: 1.5rem 0;
  background: #EEF2FF;
  border-radius: 0 6px 6px 0;
  font-style: italic;
  color: var(--dt-text-muted);
}

.dt-article-tags {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
  margin-top: 2rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--dt-border);
}
.dt-tags-label { font-size: 12px; font-weight: 700; color: var(--dt-text-light); }
.dt-tag {
  font-size: 11px;
  font-weight: 600;
  color: var(--dt-navy);
  background: #EEF2FF;
  padding: 3px 10px;
  border-radius: 999px;
  text-decoration: none;
  transition: background 0.15s ease;
}
.dt-tag:hover { background: #DBEAFE; text-decoration: none; }

.dt-article-back {
  margin-top: 2.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--dt-border);
}
.dt-back-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 14px;
  font-weight: 600;
  color: var(--dt-navy);
  text-decoration: none;
  transition: gap 0.15s ease, color 0.15s ease;
}
.dt-back-link:hover { color: var(--dt-navy-mid); gap: 10px; text-decoration: none; }

/* ══════════════════════════════════════════
   BADGES
══════════════════════════════════════════ */
.dt-badge {
  display: inline-block;
  font-family: var(--dt-font-sans);
  font-size: 9px;
  font-weight: 900;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  padding: 3px 8px;
  border-radius: 3px;
  white-space: nowrap;
  text-decoration: none;
}
.dt-badge-link:hover { opacity: 0.85; text-decoration: none; }

/* Default navy */
.dt-badge { background: var(--dt-navy); color: white; }

/* Category-specific — matches Joomla category alias */
.dt-badge-danh-gia,
.dt-badge-review,
.dt-badge-evaluation { background: #0D47A1; color: white; }

.dt-badge-tin-tuc,
.dt-badge-news,
.dt-badge-tintuc { background: #0E7490; color: white; }

.dt-badge-huong-dan,
.dt-badge-tutorial,
.dt-badge-guide { background: #B45309; color: white; }

/* ══════════════════════════════════════════
   BUTTONS
══════════════════════════════════════════ */
.dt-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 0.625rem 1.25rem;
  border-radius: var(--dt-radius);
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  border: none;
  transition: background 0.15s ease, transform 0.1s ease;
}
.dt-btn:active { transform: scale(0.97); }
.dt-btn-primary { background: var(--dt-navy); color: white; }
.dt-btn-primary:hover { background: var(--dt-navy-mid); color: white; text-decoration: none; }

/* ══════════════════════════════════════════
   PAGINATION
══════════════════════════════════════════ */
.dt-pagination {
  display: flex;
  justify-content: center;
  margin-top: 2.5rem;
  padding-top: 2rem;
  border-top: 1px solid var(--dt-border);
}
.dt-pagination .pagination { display: flex; gap: 4px; list-style: none; flex-wrap: wrap; justify-content: center; }
.dt-pagination .pagination li a,
.dt-pagination .pagination li span {
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 36px;
  height: 36px;
  padding: 0 10px;
  border: 1px solid var(--dt-border);
  border-radius: 6px;
  font-size: 13px;
  font-weight: 600;
  color: var(--dt-text-muted);
  text-decoration: none;
  transition: all 0.15s ease;
}
.dt-pagination .pagination li a:hover { background: #EEF2FF; color: var(--dt-navy); border-color: var(--dt-navy); text-decoration: none; }
.dt-pagination .pagination li.active span,
.dt-pagination .pagination li.active a { background: var(--dt-navy); color: white; border-color: var(--dt-navy); }

/* ══════════════════════════════════════════
   MODULES (sidebar, etc.)
══════════════════════════════════════════ */
.dt-module {
  background: var(--dt-white);
  border: 1px solid var(--dt-border);
  border-radius: var(--dt-radius);
  padding: 1.25rem;
  margin-bottom: 1.5rem;
}
.dt-module-title {
  font-family: var(--dt-font-serif);
  font-size: 16px;
  font-weight: 700;
  color: var(--dt-navy-dark);
  margin-bottom: 1rem;
  padding-bottom: 0.625rem;
  border-bottom: 2px solid var(--dt-navy);
}

/* ══════════════════════════════════════════
   FOOTER
══════════════════════════════════════════ */
.dt-footer {
  background: #0D1B3E;
  color: white;
  margin-top: 3rem;
}
.dt-footer-accent-bar {
  height: 3px;
  background: linear-gradient(90deg, #0D47A1, #1976D2, #0E7490);
}
.dt-footer-inner {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1.5rem;
  padding: 2.5rem 0 1.5rem;
}
.dt-footer-name {
  font-family: var(--dt-font-serif);
  font-size: 20px;
  font-weight: 700;
  color: white;
  display: block;
  margin-bottom: 0.375rem;
}
.dt-footer-desc {
  font-size: 12px;
  color: rgba(255,255,255,.5);
  max-width: 280px;
}
.dt-footer-nav ul { list-style: none; display: flex; flex-wrap: wrap; gap: 0.375rem 1.5rem; }
.dt-footer-nav ul li a {
  font-size: 14px;
  color: rgba(255,255,255,.6);
  text-decoration: none;
  transition: color 0.15s ease;
}
.dt-footer-nav ul li a:hover { color: white; text-decoration: none; }

.dt-footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.75rem;
  padding: 1.25rem 0;
  border-top: 1px solid rgba(255,255,255,.1);
}
.dt-copyright { font-size: 12px; color: rgba(255,255,255,.4); }
.dt-back-to-top {
  font-size: 12px;
  color: rgba(255,255,255,.4);
  background: none;
  border: none;
  cursor: pointer;
  transition: color 0.15s ease;
}
.dt-back-to-top:hover { color: rgba(255,255,255,.7); }

/* ══════════════════════════════════════════
   ERROR / OFFLINE PAGES
══════════════════════════════════════════ */
.dt-error-page, .dt-offline-page {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--dt-bg);
}
.dt-error-wrap, .dt-offline-wrap {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 3rem 1.5rem;
}
.dt-error-brand, .dt-offline-brand {
  font-family: var(--dt-font-serif);
  font-size: 24px;
  font-weight: 800;
  color: var(--dt-navy);
  margin-bottom: 2rem;
  text-decoration: none;
}
.dt-error-code {
  font-size: 96px;
  font-weight: 900;
  color: var(--dt-navy);
  line-height: 1;
  margin-bottom: 0.5rem;
  opacity: 0.15;
}
.dt-error-title, .dt-offline-title {
  font-family: var(--dt-font-serif);
  font-size: 28px;
  color: var(--dt-navy-dark);
  margin-bottom: 0.75rem;
}
.dt-error-msg, .dt-offline-msg {
  font-size: 15px;
  color: var(--dt-text-muted);
  max-width: 400px;
  margin-bottom: 2rem;
}

/* ══════════════════════════════════════════
   BACK TO TOP FLOATING BUTTON
══════════════════════════════════════════ */
.dt-back-to-top-fab {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  width: 40px;
  height: 40px;
  background: var(--dt-navy);
  color: white;
  border: none;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: var(--dt-shadow-md);
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 0.2s ease, transform 0.2s ease, background 0.15s ease;
  z-index: 200;
}
.dt-back-to-top-fab.visible { opacity: 1; transform: translateY(0); }
.dt-back-to-top-fab:hover { background: var(--dt-navy-mid); }

/* ══════════════════════════════════════════
   UTILITY
══════════════════════════════════════════ */
.sr-only {
  position: absolute; width: 1px; height: 1px;
  padding: 0; margin: -1px; overflow: hidden;
  clip: rect(0,0,0,0); white-space: nowrap; border-width: 0;
}