/* styles-base.css — All non-critical, non-responsive styles */

/* ── Buttons (extras not in critical) ── */
.btn-outline {
  background: transparent;
  color: var(--clr-primary);
  border: 2px solid var(--clr-primary);
}
.btn-outline:hover {
  background: var(--clr-primary);
  color: var(--clr-white);
}
.btn-sm  { padding: .5rem 1.25rem; font-size: .875rem; }
.btn-full { width: 100%; justify-content: center; }

/* ── Section Layout ── */
.section { padding: var(--sp-xl) 0; }
.section--light { background: var(--clr-light); }
.section-head {
  text-align: center;
  max-width: 680px;
  margin: 0 auto var(--sp-lg);
}
.section-head h2 { margin: .5rem 0 1rem; }
.section-head p  { color: var(--clr-muted); font-size: 1.05rem; }
.section-head--light h2 { color: var(--clr-white); }
.section-head--light p  { color: rgba(255,255,255,.8); }
.tag {
  display: inline-block;
  background: var(--clr-primary-lt);
  color: var(--clr-primary-dk);
  padding: .3rem .9rem;
  border-radius: var(--radius-pill);
  font-family: var(--ff-head);
  font-size: .8rem;
  font-weight: 600;
  letter-spacing: .05em;
  text-transform: uppercase;
}
.tag--light {
  background: rgba(255,255,255,.15);
  color: var(--clr-white);
}

/* ── Image Placeholder ── */
.img-ph {
  background: linear-gradient(135deg, #2A6565 0%, #4A9FA0 100%);
  color: rgba(255,255,255,.7);
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  font-family: var(--ff-head);
  font-size: .85rem;
  font-weight: 500;
  border-radius: var(--radius);
  width: 100%;
  height: 100%;
  padding: 1rem;
}

/* ── Header extras ── */
.header.scrolled .logo-img { filter: none; }
.logo-text {
  font-family: var(--ff-head);
  font-size: .95rem;
  line-height: 1.25;
  color: var(--clr-dark);
  font-weight: 400;
  transition: color var(--trans);
}
.logo-text strong { font-weight: 800; font-size: 1.15rem; display: block; }
.header.scrolled .logo-text { color: var(--clr-dark); }
.header.scrolled .nav-link { color: var(--clr-dark); }
.header.scrolled .nav-link:hover { color: var(--clr-primary); background: var(--clr-primary-lt); }
.header.scrolled .hamburger span { background: var(--clr-dark); }
.hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ── Mobile Menu ── */
.mobile-services-toggle {
  width: 100%;
  text-align: left;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: .75rem 1rem;
  font-family: var(--ff-head);
  font-weight: 500;
  font-size: 1rem;
  color: var(--clr-dark);
  border-radius: var(--radius-sm);
  transition: all var(--trans);
  cursor: pointer;
  border: none;
  background: none;
}
.mobile-services-toggle:hover { background: var(--clr-light); color: var(--clr-primary); }
.mobile-arrow {
  display: inline-block;
  font-size: .65rem;
  transition: transform var(--trans);
}
.mobile-services-toggle.open { color: var(--clr-primary); }
.mobile-services-toggle.open .mobile-arrow { transform: rotate(180deg); }
.mobile-sub-list {
  display: none;
  flex-direction: column;
  gap: 0;
  padding-left: .75rem;
  border-left: 2px solid var(--clr-border);
  margin: .1rem 0 .25rem 1rem;
}
.mobile-sub-list.open { display: flex; }
.mobile-sub-link {
  display: block;
  padding: .5rem .75rem;
  font-family: var(--ff-head);
  font-size: .83rem;
  font-weight: 400;
  color: var(--clr-muted);
  border-radius: var(--radius-sm);
  transition: all var(--trans);
}
.mobile-sub-link:hover { color: var(--clr-primary); background: var(--clr-primary-lt); }
.mobile-menu {
  position: fixed;
  top: 0; right: -100%;
  width: min(320px, 88vw);
  height: 100%;
  background: var(--clr-white);
  z-index: 950;
  padding: 5rem 2rem 2rem;
  box-shadow: -8px 0 32px rgba(0,0,0,.15);
  transition: right var(--trans);
  display: flex;
  flex-direction: column;
  gap: .25rem;
}
.mobile-menu.open { right: 0; }
.mobile-menu ul { display: flex; flex-direction: column; gap: .25rem; }
.mobile-link {
  display: block;
  padding: .75rem 1rem;
  font-family: var(--ff-head);
  font-weight: 500;
  color: var(--clr-dark);
  border-radius: var(--radius-sm);
  transition: all var(--trans);
}
.mobile-link:hover { background: var(--clr-light); color: var(--clr-primary); }
.mobile-cta { margin-top: auto; text-align: center; justify-content: center; }
.mobile-close {
  position: absolute;
  top: 1.25rem; right: 1.25rem;
  font-size: 1.75rem;
  color: var(--clr-muted);
  transition: color var(--trans);
  line-height: 1;
}
.mobile-close:hover { color: var(--clr-dark); }
.mobile-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,.4);
  z-index: 940;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--trans);
}
.mobile-overlay.open { opacity: 1; pointer-events: all; }

/* ── Footer logo ── */
.footer-logo-img {
  height: 64px;
  width: auto;
  border-radius: 8px;
  margin-bottom: 1rem;
  filter: brightness(1.1);
}

/* ── Stats Bar ── */
.stats-bar { background: var(--clr-dark); padding: 2.5rem 0; }
.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
  text-align: center;
}
.stat-item { color: var(--clr-white); }
.stat-item p {
  color: rgba(255,255,255,.7);
  font-family: var(--ff-head);
  font-size: .875rem;
  margin-top: .25rem;
}
.stat-number {
  font-family: var(--ff-head);
  font-size: clamp(2rem,4vw,2.75rem);
  font-weight: 800;
  color: var(--clr-accent);
  line-height: 1;
}
.stat-sfx {
  font-family: var(--ff-head);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--clr-accent);
  vertical-align: super;
}

/* ── Services ── */
.services-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}
.svc-card {
  background: var(--clr-white);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius);
  padding: 2rem 1.75rem;
  transition: all var(--trans);
  position: relative;
  overflow: hidden;
}
.svc-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0;
  width: 4px;
  height: 100%;
  background: var(--clr-primary);
  transform: scaleY(0);
  transition: transform var(--trans);
  transform-origin: bottom;
}
.svc-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
  border-color: transparent;
}
.svc-card:hover::before { transform: scaleY(1); }
.svc-card--accent {
  background: var(--clr-dark);
  border-color: var(--clr-dark);
  color: var(--clr-white);
}
.svc-card--accent h3 { color: var(--clr-white); }
.svc-card--accent p  { color: rgba(255,255,255,.75); }
.svc-card--accent .svc-icon { background: rgba(74,159,160,.15); color: var(--clr-primary-lt); }
.svc-card--accent .svc-more { color: var(--clr-primary-lt); }
.svc-card--accent::before { background: var(--clr-primary); }
.svc-icon {
  width: 52px;
  height: 52px;
  background: var(--clr-primary-lt);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.25rem;
  color: var(--clr-primary);
}
.svc-icon svg { width: 26px; height: 26px; }
.svc-icon img { width: 28px; height: 28px; object-fit: contain; }
.svc-card h3 { margin-bottom: .5rem; }
.svc-card p  { color: var(--clr-muted); font-size: .95rem; margin-bottom: 1.25rem; }
.svc-more {
  font-family: var(--ff-head);
  font-size: .875rem;
  font-weight: 600;
  color: var(--clr-primary);
  transition: gap var(--trans);
  display: inline-flex;
  gap: .25rem;
}
.svc-more:hover { gap: .5rem; }

/* ── Partner in Oral Health ── */
.partner-section { background: var(--clr-white); }
.partner-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 5rem;
  align-items: center;
}
.partner-visual { order: -1; }
.partner-text   { order: 1; }
.partner-text .tag  { margin-bottom: 1rem; }
.partner-text h2    { margin-bottom: 1.25rem; font-size: clamp(1.5rem, 3vw, 2.25rem); }
.gold-italic        { font-style: italic; color: var(--clr-accent); }
.partner-text > p   { color: var(--clr-muted); margin-bottom: 1rem; }
.partner-visual { position: relative; }
.partner-img-wrap {
  border-radius: var(--radius);
  overflow: hidden;
  min-height: 380px;
}
.partner-accent-box {
  position: absolute;
  bottom: -1.5rem;
  right: -1.5rem;
  background: var(--clr-accent);
  color: var(--clr-white);
  border-radius: var(--radius);
  padding: 1.25rem 1.5rem;
  text-align: center;
  box-shadow: var(--shadow-md);
  display: flex;
  flex-direction: column;
  gap: .25rem;
}
.partner-accent-box strong {
  font-family: var(--ff-head);
  font-size: 1rem;
  font-weight: 700;
  color: var(--clr-white);
}
.partner-accent-box span {
  font-size: .8rem;
  color: rgba(255,255,255,.85);
  max-width: 120px;
}
.partner-accent-icon { font-size: 1.5rem; margin-bottom: .25rem; }

/* ── About ── */
.about-section { background: var(--clr-sage-lt); }
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 5rem;
  align-items: center;
}
.about-visual { position: relative; }
.about-img-wrap {
  border-radius: var(--radius);
  overflow: hidden;
  aspect-ratio: 4/5;
}
.about-ph { min-height: 480px; }
.about-badge {
  position: absolute;
  bottom: -1.5rem;
  right: -1.5rem;
  background: var(--clr-accent);
  color: var(--clr-white);
  border-radius: var(--radius);
  padding: 1.25rem 1.5rem;
  text-align: center;
  box-shadow: var(--shadow-md);
}
.about-badge strong {
  display: block;
  font-family: var(--ff-head);
  font-size: 2rem;
  font-weight: 800;
  line-height: 1;
  color: var(--clr-white);
}
.about-badge span {
  font-family: var(--ff-head);
  font-size: .8rem;
  font-weight: 500;
  color: rgba(255,255,255,.85);
  display: block;
  margin-top: .25rem;
}
.about-floating {
  position: absolute;
  top: 1.5rem;
  left: -1.5rem;
  background: var(--clr-white);
  border-radius: var(--radius);
  padding: .75rem 1.25rem;
  display: flex;
  align-items: center;
  gap: .5rem;
  box-shadow: var(--shadow-md);
  font-family: var(--ff-head);
  font-size: .875rem;
  font-weight: 600;
  color: var(--clr-primary);
}
.float-icon {
  width: 28px;
  height: 28px;
  background: var(--clr-primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--clr-white);
  font-size: .875rem;
}
.about-text .tag  { margin-bottom: 1rem; }
.about-text h2    { margin-bottom: 1.25rem; }
.about-text > p   { color: var(--clr-muted); margin-bottom: 1rem; }
.about-list {
  display: flex;
  flex-direction: column;
  gap: .6rem;
  margin: 1.75rem 0;
}
.about-list li {
  display: flex;
  align-items: flex-start;
  gap: .75rem;
  font-family: var(--ff-body);
  font-size: .95rem;
  color: var(--clr-body);
}
.about-list li span {
  width: 20px;
  height: 20px;
  background: var(--clr-primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--clr-white);
  font-size: .75rem;
  font-weight: 700;
  flex-shrink: 0;
  margin-top: .2rem;
}
.about-ctas { display: flex; gap: 1rem; flex-wrap: wrap; }

/* ── Why Choose Us ── */
.why-section { background: var(--clr-dark); }
.why-section .section-head h2 { color: var(--clr-white); }
.why-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
}
.why-card {
  background: rgba(255,255,255,.06);
  border: 1px solid rgba(255,255,255,.12);
  border-radius: var(--radius);
  padding: 2rem 1.5rem;
  transition: all var(--trans);
  text-align: center;
}
.why-card:hover {
  background: rgba(255,255,255,.1);
  transform: translateY(-4px);
}
.why-card h3 { color: var(--clr-white); margin: 1rem 0 .5rem; }
.why-card p  { color: rgba(255,255,255,.7); font-size: .95rem; }
.why-icon    { font-size: 2.5rem; color: var(--clr-accent); display: flex; justify-content: center; }
.why-icon svg { width: 40px; height: 40px; }
.why-icon img { width: 40px; height: 40px; object-fit: contain; filter: brightness(0) invert(1); }

/* ── Team ── */
.team-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}
.team-card {
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  background: var(--clr-white);
  transition: all var(--trans);
}
.team-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
}
.team-photo { aspect-ratio: 3/4; }
.team-ph { min-height: 280px; border-radius: 0; }
.team-info { padding: 1.5rem; text-align: center; }
.team-info h3 { margin-bottom: .25rem; }
.team-info p  { color: var(--clr-muted); font-size: .875rem; margin-top: .25rem; }
.team-role {
  display: inline-block;
  background: var(--clr-primary-lt);
  color: var(--clr-primary-dk);
  padding: .2rem .75rem;
  border-radius: var(--radius-pill);
  font-family: var(--ff-head);
  font-size: .775rem;
  font-weight: 600;
}

/* ── Testimonials ── */
.testimonials-section {
  background: linear-gradient(135deg, #1A3535 0%, #2A6565 100%);
}
.testi-outer { overflow: hidden; margin-bottom: 2rem; width: 100%; }
.testi-track {
  display: flex;
  gap: 1.5rem;
  transition: transform .5s cubic-bezier(.4,0,.2,1);
}
.testi-card {
  background: rgba(255,255,255,.07);
  border: 1px solid rgba(255,255,255,.12);
  border-radius: var(--radius);
  padding: 2.5rem 2rem;
  flex-shrink: 0;
  flex-grow: 0;
  transition: all var(--trans);
}
.testi-card:hover { background: rgba(255,255,255,.1); }
.testi-stars {
  color: var(--clr-accent);
  font-size: 1.1rem;
  letter-spacing: .1em;
  margin-bottom: 1rem;
}
.testi-card > p {
  color: rgba(255,255,255,.88);
  font-size: 1rem;
  font-style: italic;
  line-height: 1.75;
  margin-bottom: 1.5rem;
}
.testi-author {
  display: flex;
  align-items: center;
  gap: .75rem;
}
.testi-avatar {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: var(--clr-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--ff-head);
  font-weight: 700;
  font-size: .875rem;
  color: var(--clr-white);
  flex-shrink: 0;
}
.testi-author strong { display: block; color: var(--clr-white); font-family: var(--ff-head); }
.testi-author span   { color: rgba(255,255,255,.6); font-size: .875rem; }
.testi-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
}
.testi-btn {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: rgba(255,255,255,.12);
  color: var(--clr-white);
  font-size: 1.1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--trans);
  border: 1px solid rgba(255,255,255,.2);
}
.testi-btn:hover { background: var(--clr-primary); border-color: var(--clr-primary); }
.testi-dots { display: flex; gap: .5rem; }
.testi-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: rgba(255,255,255,.3);
  border: none;
  transition: all var(--trans);
  cursor: pointer;
}
.testi-dot.active {
  background: var(--clr-primary);
  width: 24px;
  border-radius: 4px;
}

/* ── FAQ ── */
.faq-inner { max-width: 760px; margin: 0 auto; }
.faq-list { display: flex; flex-direction: column; gap: .75rem; }
.faq-item {
  border: 1px solid var(--clr-border);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--clr-white);
  transition: box-shadow var(--trans);
}
.faq-item.open { box-shadow: var(--shadow-sm); }
.faq-q {
  width: 100%;
  text-align: left;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  padding: 1.25rem 1.5rem;
  font-family: var(--ff-head);
  font-size: 1rem;
  font-weight: 600;
  color: var(--clr-dark);
  background: none;
  border: none;
  transition: color var(--trans);
}
.faq-q:hover { color: var(--clr-primary); }
.faq-item.open .faq-q { color: var(--clr-primary); }
.faq-chevron {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--clr-light);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  position: relative;
  transition: background var(--trans);
}
.faq-chevron::before {
  content: '';
  position: absolute;
  width: 10px;
  height: 2px;
  background: var(--clr-muted);
  border-radius: 2px;
  transition: background var(--trans);
}
.faq-chevron::after {
  content: '';
  position: absolute;
  width: 2px;
  height: 10px;
  background: var(--clr-muted);
  border-radius: 2px;
  transition: opacity var(--trans), background var(--trans);
}
.faq-item.open .faq-chevron { background: var(--clr-primary); }
.faq-item.open .faq-chevron::before { background: var(--clr-white); }
.faq-item.open .faq-chevron::after  { opacity: 0; background: var(--clr-white); }
.faq-a {
  overflow: hidden;
  max-height: 0;
  transition: max-height .4s ease, padding .3s ease;
}
.faq-a.open { max-height: 400px; }
.faq-a > p {
  padding: 0 1.5rem 1.25rem;
  color: var(--clr-muted);
  font-size: .975rem;
}
.faq-a a { color: var(--clr-primary); text-decoration: underline; }

/* ── Contact ── */
.contact-section { background: var(--clr-sand-lt); }
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 4rem;
  align-items: start;
}
.contact-info .tag  { margin-bottom: 1rem; }
.contact-info h2    { margin-bottom: 1rem; }
.contact-info > p   { color: var(--clr-muted); margin-bottom: 2rem; }
.contact-list {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}
.contact-list li {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
}
.c-icon {
  font-size: 1.4rem;
  width: 44px;
  height: 44px;
  background: var(--clr-white);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  box-shadow: var(--shadow-sm);
}
.contact-list strong { font-family: var(--ff-head); font-size: .875rem; display: block; }
.contact-list a { color: var(--clr-primary); transition: color var(--trans); }
.contact-list a:hover { color: var(--clr-primary-dk); }
.contact-form-wrap {
  background: var(--clr-white);
  border-radius: var(--radius);
  padding: 2.5rem;
  box-shadow: var(--shadow-md);
}
.contact-form { display: flex; flex-direction: column; gap: 1.25rem; }
.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}
.form-group { display: flex; flex-direction: column; gap: .35rem; }
.form-group label {
  font-family: var(--ff-head);
  font-size: .875rem;
  font-weight: 600;
  color: var(--clr-dark);
}
.form-group input,
.form-group select,
.form-group textarea {
  padding: .7rem 1rem;
  border: 1.5px solid var(--clr-border);
  border-radius: var(--radius-sm);
  font-family: var(--ff-body);
  font-size: .975rem;
  color: var(--clr-dark);
  background: var(--clr-white);
  transition: border-color var(--trans), box-shadow var(--trans);
  appearance: none;
  resize: vertical;
}
.form-group select {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16'%3E%3Cpath fill='%2364748B' d='M4 6l4 4 4-4'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right .75rem center;
  background-size: 16px;
  padding-right: 2.5rem;
  cursor: pointer;
}
.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--clr-accent);
  box-shadow: 0 0 0 3px rgba(74,159,160,.15);
}
.form-group input::placeholder,
.form-group textarea::placeholder { color: #aab4bf; }
.form-feedback {
  text-align: center;
  font-family: var(--ff-head);
  font-size: .9rem;
  color: #22a366;
  min-height: 1.4rem;
}

/* ── Footer ── */
.footer { background: var(--clr-dark); padding-top: var(--sp-lg); }
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.5fr;
  gap: 3rem;
  padding-bottom: var(--sp-lg);
}
.footer-logo-text {
  display: block;
  font-size: 1.05rem;
  color: var(--clr-white);
  margin-bottom: 1rem;
}
.footer-logo-text strong { font-size: 1.3rem; }
.footer-logo-img { height: 52px; width: auto; margin-bottom: 1rem; }
.footer-brand > p {
  color: rgba(255,255,255,.55);
  font-size: .9rem;
  line-height: 1.7;
  margin-bottom: 1.5rem;
}
.footer-socials { display: flex; gap: .75rem; }
.social-btn {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  background: rgba(255,255,255,.08);
  border: 1px solid rgba(255,255,255,.12);
  display: flex;
  align-items: center;
  justify-content: center;
  color: rgba(255,255,255,.7);
  transition: all var(--trans);
}
.social-btn:hover {
  background: var(--clr-primary);
  border-color: var(--clr-primary);
  color: var(--clr-white);
  transform: translateY(-2px);
}
.footer-col h4 {
  color: var(--clr-white);
  font-family: var(--ff-head);
  font-size: .875rem;
  letter-spacing: .05em;
  text-transform: uppercase;
  margin-bottom: 1.25rem;
}
.footer-col ul { display: flex; flex-direction: column; gap: .5rem; }
.footer-col a {
  color: rgba(255,255,255,.55);
  font-size: .9rem;
  transition: color var(--trans);
}
.footer-col a:hover { color: var(--clr-primary-lt); }
.footer-contact-col p {
  color: rgba(255,255,255,.55);
  font-size: .9rem;
  margin-bottom: .5rem;
}
.footer-contact-col a { color: var(--clr-primary-lt); }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,.08);
  padding: 1.5rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: var(--max-w-wide);
  margin: 0 auto;
  flex-wrap: wrap;
  gap: .5rem;
}
.footer-bottom p {
  color: rgba(255,255,255,.35);
  font-size: .8rem;
}

/* ── Back to Top ── */
.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  z-index: 800;
  width: 48px;
  height: 48px;
  background: var(--clr-primary);
  color: var(--clr-white);
  border-radius: 50%;
  font-size: 1.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-md);
  opacity: 0;
  transform: translateY(12px);
  pointer-events: none;
  transition: all var(--trans);
}
.back-to-top.visible {
  opacity: 1;
  transform: translateY(0);
  pointer-events: all;
}
.back-to-top:hover { background: var(--clr-primary-dk); transform: translateY(-2px); }