/* =========================================================
   PALETTE — update these 5 variables once logo is supplied.
   Current values are sampled from the Prolific business card
   and banner (safety yellow on asphalt black).
   ========================================================= */
:root {
  --brand-primary: #FDB813;   /* safety yellow (logo bar, icons) */
  --brand-accent:  #E09A00;   /* deeper amber for hover/pressed */
  --brand-dark:    #161616;   /* fresh asphalt */
  --brand-light:   #F2F3F5;   /* concrete light */
  --text:          #1C1C1E;   /* body text */

  /* derived — usually no need to edit */
  --muted: #5B6069;
  --concrete: #8A8F98;
  --white: #FFFFFF;
  --dark-2: #222224;
  --line: #E2E4E8;
  --error: #C62828;
  --success: #1B7F3B;

  --font-display: "Barlow Condensed", "Arial Narrow", "Roboto Condensed", Impact, sans-serif;
  --font-body: "Barlow", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;

  --radius: 6px;
  --header-h: 76px;
  --container: 1200px;
}

/* ---------- Reset / base ---------- */
*, *::before, *::after { -webkit-box-sizing: border-box; box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; scroll-padding-top: var(--header-h); }
body {
  margin: 0;
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.6;
  color: var(--text);
  background: var(--white);
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; height: auto; display: block; }
a { color: inherit; }
ul { margin: 0; padding: 0; list-style: none; }
h1, h2, h3, h4 { margin: 0 0 .5em; line-height: 1.1; }
p { margin: 0 0 1em; }
button { font: inherit; cursor: pointer; }
:focus-visible { outline: 3px solid var(--brand-primary); outline-offset: 3px; }
a:focus, button:focus, input:focus, select:focus, textarea:focus { outline: 3px solid var(--brand-primary); outline-offset: 2px; }
a:focus:not(:focus-visible), button:focus:not(:focus-visible) { outline: none; }

.container { width: 100%; max-width: var(--container); margin: 0 auto; padding: 0 20px; }
@media (min-width: 768px) { .container { padding: 0 32px; } }

.skip-link { position: absolute; left: -9999px; top: 0; z-index: 200; background: var(--brand-primary); color: var(--brand-dark); padding: 12px 16px; font-weight: 700; }
.skip-link:focus { left: 12px; top: 12px; }

.section { padding: 64px 0; }
@media (min-width: 1024px) { .section { padding: 96px 0; } }

.section-title {
  font-family: var(--font-display);
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: .01em;
  font-size: 34px;
  font-size: clamp(32px, 4.5vw, 52px);
  line-height: 1;
}
.section-head { max-width: 640px; margin-bottom: 40px; }
.section-head p { color: var(--muted); font-size: 18px; }

/* ---------- Buttons ---------- */
.btn {
  display: -webkit-inline-box; display: -webkit-inline-flex; display: inline-flex;
  -webkit-box-align: center; -webkit-align-items: center; align-items: center;
  -webkit-box-pack: center; -webkit-justify-content: center; justify-content: center;
  min-height: 52px; padding: 12px 26px;
  font-family: var(--font-display); font-weight: 700; font-size: 20px; letter-spacing: .02em;
  text-decoration: none; text-transform: uppercase;
  border: 2px solid transparent; border-radius: var(--radius);
  -webkit-transition: background-color .2s, color .2s, border-color .2s, -webkit-transform .2s;
  transition: background-color .2s, color .2s, border-color .2s, transform .2s;
}
.btn-primary { background: var(--brand-primary); color: var(--brand-dark); }
.btn-primary:hover { background: var(--brand-accent); }
.btn-ghost { background: transparent; color: var(--white); border-color: rgba(255,255,255,.6); }
.btn-ghost:hover { border-color: var(--brand-primary); color: var(--brand-primary); }
.btn-block { width: 100%; }
.btn[disabled] { opacity: .6; cursor: wait; }

.text-link { font-weight: 700; color: var(--text); text-decoration: none; border-bottom: 3px solid var(--brand-primary); padding-bottom: 2px; }
.text-link:hover { color: var(--brand-accent); }

/* ---------- 1. Header ---------- */
.site-header {
  position: -webkit-sticky; position: sticky; top: 0; z-index: 100;
  background: var(--brand-dark);
  border-bottom: 3px solid var(--brand-primary);
  -webkit-transition: box-shadow .25s; transition: box-shadow .25s;
}
.header-inner {
  display: -webkit-box; display: -webkit-flex; display: flex;
  -webkit-box-align: center; -webkit-align-items: center; align-items: center;
  height: var(--header-h);
  -webkit-transition: height .25s; transition: height .25s;
}
.site-header.is-shrunk { box-shadow: 0 4px 18px rgba(0,0,0,.35); }
.site-header.is-shrunk .header-inner { height: 60px; }
.site-header.is-shrunk .brand-logo { height: 44px; }

.brand { display: block; margin-right: auto; text-decoration: none; }
.brand-logo { height: 56px; width: auto; -webkit-transition: height .25s; transition: height .25s; }
.brand.logo-failed .brand-logo { display: none; }
.brand.logo-failed .brand-fallback { display: inline-block; }
.brand-fallback { display: none; font-family: var(--font-display); font-weight: 800; font-size: 26px; color: var(--white); letter-spacing: .02em; }

.main-nav ul { display: -webkit-box; display: -webkit-flex; display: flex; }
.main-nav a {
  display: block; padding: 12px 14px; min-height: 44px;
  color: var(--white); text-decoration: none; font-weight: 600; font-size: 16px;
}
.main-nav a:hover { color: var(--brand-primary); }
.main-nav .nav-quote { color: var(--brand-primary); }

.header-phone {
  display: -webkit-box; display: -webkit-flex; display: flex;
  -webkit-box-align: center; -webkit-align-items: center; align-items: center;
  margin-left: 12px; padding: 10px 16px; min-height: 44px;
  background: var(--brand-primary); color: var(--brand-dark);
  font-weight: 700; text-decoration: none; border-radius: var(--radius); white-space: nowrap;
}
.header-phone svg { margin-right: 8px; }
.header-phone:hover { background: var(--brand-accent); }

.nav-toggle {
  display: none;
  width: 48px; height: 48px; margin-left: 10px; padding: 12px;
  background: transparent; border: 0;
}
.nav-toggle .bar { display: block; height: 3px; margin: 5px 0; background: var(--white); border-radius: 2px; -webkit-transition: transform .25s, opacity .25s; transition: transform .25s, opacity .25s; }
.nav-toggle[aria-expanded="true"] .bar:nth-child(1) { -webkit-transform: translateY(8px) rotate(45deg); transform: translateY(8px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .bar:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .bar:nth-child(3) { -webkit-transform: translateY(-8px) rotate(-45deg); transform: translateY(-8px) rotate(-45deg); }

@media (max-width: 1023px) {
  .nav-toggle { display: block; }
  .main-nav {
    position: absolute; left: 0; right: 0; top: 100%;
    background: var(--brand-dark); border-bottom: 3px solid var(--brand-primary);
    max-height: 0; overflow: hidden; visibility: hidden;
    -webkit-transition: max-height .3s ease, visibility .3s; transition: max-height .3s ease, visibility .3s;
  }
  .main-nav.is-open { max-height: 420px; visibility: visible; }
  .main-nav ul { -webkit-box-orient: vertical; -webkit-flex-direction: column; flex-direction: column; padding: 8px 20px 20px; }
  .main-nav a { padding: 14px 4px; font-size: 20px; border-bottom: 1px solid rgba(255,255,255,.08); }
}
@media (max-width: 479px) {
  .brand-logo { height: 44px; }
  .header-phone span { display: none; }
  .header-phone { padding: 12px; }
  .header-phone svg { margin-right: 0; }
}

/* ---------- 2. Hero ---------- */
.hero {
  position: relative;
  min-height: 85vh;
  min-height: calc(var(--vh, 1vh) * 85);
  min-height: 85svh;
  display: -webkit-box; display: -webkit-flex; display: flex;
  -webkit-box-orient: vertical; -webkit-flex-direction: column; flex-direction: column;
  background-color: var(--brand-dark);
  background-image: radial-gradient(circle at 88% 12%, rgba(253,184,19,.28) 0, rgba(253,184,19,0) 38%);
  color: var(--white);
  overflow: hidden;
}
.hero-copy { position: relative; z-index: 2; padding-top: 48px; padding-bottom: 24px; }
@media (min-width: 1024px) { .hero-copy { padding-top: 72px; } }

.hero-kicker { color: var(--brand-primary); font-weight: 600; font-size: 17px; margin-bottom: 14px; }
.hero-title {
  font-family: var(--font-display);
  font-weight: 800;
  text-transform: uppercase;
  font-size: 46px;
  font-size: clamp(42px, 8.2vw, 108px);
  line-height: .92;
  letter-spacing: -.005em;
  max-width: 13ch;
  margin-bottom: 20px;
}
.hero-sub { font-size: 18px; font-size: clamp(17px, 1.8vw, 21px); max-width: 44ch; color: rgba(255,255,255,.86); margin-bottom: 28px; }
.hero-ctas { display: -webkit-box; display: -webkit-flex; display: flex; -webkit-flex-wrap: wrap; flex-wrap: wrap; margin: -6px; }
.hero-ctas .btn { margin: 6px; }
@media (max-width: 479px) { .hero-ctas .btn { width: 100%; } }

.hero-media { position: relative; margin-top: auto; }
.hero-media::before {
  content: ""; position: absolute; left: 0; right: 0; top: 0; height: 55%; z-index: 1;
  background: -webkit-linear-gradient(top, var(--brand-dark) 0%, rgba(22,22,22,0) 100%);
  background: linear-gradient(to bottom, var(--brand-dark) 0%, rgba(22,22,22,0) 100%);
}
.hero-media img {
  width: 100%;
  height: 220px;
  -o-object-fit: cover; object-fit: cover;
  -o-object-position: 50% 100%; object-position: 50% 100%;
  background: url('../assets/hero-lqip.png') center / cover no-repeat;
}
@media (min-width: 640px)  { .hero-media img { height: 260px; } }
@media (min-width: 1024px) { .hero-media img { height: auto; } }

/* The road centre line: the page's signature detail */
.road-line {
  position: relative; z-index: 2;
  height: 10px;
  background-color: var(--brand-dark);
  background-image: -webkit-linear-gradient(left, var(--brand-primary) 0, var(--brand-primary) 60%, transparent 60%);
  background-image: linear-gradient(to right, var(--brand-primary) 0, var(--brand-primary) 60%, transparent 60%);
  background-size: 90px 4px;
  background-repeat: repeat-x;
  background-position: 0 50%;
  -webkit-animation: roll 1.4s ease-out 1;
  animation: roll 1.4s ease-out 1;
}
@-webkit-keyframes roll { from { background-position: -900px 50%; } to { background-position: 0 50%; } }
@keyframes roll { from { background-position: -900px 50%; } to { background-position: 0 50%; } }

/* Trust bar */
.trust-bar { background: var(--brand-primary); color: var(--brand-dark); }
.trust-list {
  display: -webkit-box; display: -webkit-flex; display: flex;
  -webkit-flex-wrap: wrap; flex-wrap: wrap;
  -webkit-box-pack: justify; -webkit-justify-content: space-between; justify-content: space-between;
  padding-top: 14px; padding-bottom: 14px;
}
.trust-list li {
  display: -webkit-box; display: -webkit-flex; display: flex;
  -webkit-box-align: center; -webkit-align-items: center; align-items: center;
  width: 50%; padding: 6px 4px;
  font-family: var(--font-display); font-weight: 700; font-size: 18px; text-transform: uppercase; letter-spacing: .02em;
}
.trust-list svg { width: 24px; height: 24px; margin-right: 8px; -webkit-flex-shrink: 0; flex-shrink: 0; }
@media (min-width: 768px) { .trust-list li { width: auto; font-size: 20px; } }

/* ---------- 3. About ---------- */
.about { background: var(--white); }
.about-grid {
  display: -ms-grid; display: grid;
  grid-template-columns: 1fr;
  grid-gap: 40px; gap: 40px;
  -webkit-box-align: center; align-items: center;
}
@media (min-width: 768px) { .about-grid { grid-template-columns: 1.3fr 1fr; grid-gap: 56px; gap: 56px; } }
.about-copy p { max-width: 62ch; }
.lead { font-size: 20px; font-weight: 500; }
.about-media { margin: 0; position: relative; }
.about-media img {
  width: 100%;
  border-radius: var(--radius);
  border-bottom: 8px solid var(--brand-primary);
  -o-object-fit: cover; object-fit: cover;
}
.about-media figcaption { margin-top: 10px; color: var(--muted); font-size: 15px; }

.stats {
  display: -ms-grid; display: grid;
  grid-template-columns: 1fr 1fr;
  grid-gap: 2px; gap: 2px;
  margin-top: 56px;
  background: var(--brand-dark);
  border-radius: var(--radius); overflow: hidden;
}
@media (min-width: 768px) { .stats { grid-template-columns: repeat(4, 1fr); } }
.stats li { background: var(--brand-dark); color: var(--white); padding: 24px 20px; }
.stats svg { width: 28px; height: 28px; color: var(--brand-primary); margin-bottom: 10px; }
.stats strong { display: block; font-family: var(--font-display); font-weight: 800; font-size: 42px; line-height: 1; color: var(--brand-primary); }
.stats span { display: block; margin-top: 6px; font-size: 15px; color: rgba(255,255,255,.8); }

/* ---------- 4. Services ---------- */
.services { background: var(--brand-dark); color: var(--white); }
.services .section-head p { color: rgba(255,255,255,.75); }
.service-grid {
  display: -ms-grid; display: grid;
  grid-template-columns: 1fr;
  grid-gap: 20px; gap: 20px;
}
@media (min-width: 640px)  { .service-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1024px) { .service-grid { grid-template-columns: repeat(3, 1fr); grid-gap: 24px; gap: 24px; } }

.service-card {
  display: -webkit-box; display: -webkit-flex; display: flex;
  -webkit-box-orient: vertical; -webkit-flex-direction: column; flex-direction: column;
  padding: 28px 24px;
  background: var(--dark-2);
  border-top: 4px solid var(--brand-primary);
  border-radius: 0 0 var(--radius) var(--radius);
  -webkit-transition: -webkit-transform .2s, box-shadow .2s; transition: transform .2s, box-shadow .2s;
}
@media (hover: hover) {
  .service-card:hover { -webkit-transform: translateY(-4px); transform: translateY(-4px); box-shadow: 0 14px 30px rgba(0,0,0,.45); }
}
.service-icon {
  display: -webkit-box; display: -webkit-flex; display: flex;
  -webkit-box-align: center; -webkit-align-items: center; align-items: center;
  -webkit-box-pack: center; -webkit-justify-content: center; justify-content: center;
  width: 64px; height: 64px; margin-bottom: 18px;
  border: 3px solid var(--brand-primary); border-radius: 50%;
  color: var(--brand-primary);
}
.service-icon svg { width: 30px; height: 30px; }
.service-card h3 { font-family: var(--font-display); font-weight: 700; font-size: 28px; text-transform: uppercase; }
.service-card p { color: rgba(255,255,255,.78); -webkit-box-flex: 1; -webkit-flex-grow: 1; flex-grow: 1; }
.card-link {
  display: inline-block; -webkit-align-self: flex-start; align-self: flex-start;
  padding: 10px 0; min-height: 44px;
  color: var(--brand-primary); font-weight: 700; text-decoration: none;
  border-bottom: 2px solid transparent;
}
.card-link:hover { border-bottom-color: var(--brand-primary); }
.service-card-more { background: var(--brand-primary); color: var(--brand-dark); }
.service-card-more p { color: rgba(22,22,22,.85); }
.service-card-more .service-icon { border-color: var(--brand-dark); color: var(--brand-dark); }
.service-card-more .card-link { color: var(--brand-dark); }
.service-card-more .card-link:hover { border-bottom-color: var(--brand-dark); }

/* ---------- 5. Gallery ---------- */
.gallery { background: var(--brand-light); }
.filters { display: -webkit-box; display: -webkit-flex; display: flex; -webkit-flex-wrap: wrap; flex-wrap: wrap; margin: 0 -4px 28px; }
.filter-btn {
  margin: 4px; min-height: 44px; padding: 8px 18px;
  background: var(--white); color: var(--text);
  border: 2px solid var(--line); border-radius: 999px;
  font-weight: 600;
}
.filter-btn:hover { border-color: var(--brand-dark); }
.filter-btn.is-active { background: var(--brand-dark); color: var(--brand-primary); border-color: var(--brand-dark); }

.gallery-grid {
  display: -ms-grid; display: grid;
  grid-template-columns: 1fr;
  grid-gap: 12px; gap: 12px;
}
@media (min-width: 480px)  { .gallery-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1024px) { .gallery-grid { grid-template-columns: repeat(3, 1fr); grid-gap: 16px; gap: 16px; } }
.gallery-item.is-hidden { display: none; }

.gallery-btn {
  position: relative; display: block; width: 100%;
  padding: 0; border: 0; background: var(--brand-dark);
  border-radius: var(--radius); overflow: hidden;
}
/* 4:3 ratio via padding fallback (no aspect-ratio dependency) */
.gallery-btn picture { display: block; position: relative; padding-top: 75%; }
.gallery-btn img {
  position: absolute; top: 0; left: 0; width: 100%; height: 100%;
  -o-object-fit: cover; object-fit: cover;
  -webkit-transition: -webkit-transform .35s, opacity .35s; transition: transform .35s, opacity .35s;
}
@media (hover: hover) { .gallery-btn:hover img { -webkit-transform: scale(1.04); transform: scale(1.04); opacity: .9; } }

/* Lightbox */
.lightbox {
  position: fixed; top: 0; right: 0; bottom: 0; left: 0; z-index: 300;
  display: -webkit-box; display: -webkit-flex; display: flex;
  -webkit-box-align: center; -webkit-align-items: center; align-items: center;
  -webkit-box-pack: center; -webkit-justify-content: center; justify-content: center;
  background: rgba(10,10,10,.94);
  padding: 60px 12px;
}
.lightbox[hidden] { display: none; }
.lb-figure { margin: 0; max-width: 1100px; width: 100%; text-align: center; }
.lb-img { max-height: 78vh; width: auto; margin: 0 auto; border-radius: var(--radius); }
.lb-caption { color: var(--white); margin-top: 12px; font-size: 15px; }
.lb-close, .lb-prev, .lb-next {
  position: absolute; width: 52px; height: 52px;
  background: var(--brand-primary); color: var(--brand-dark);
  border: 0; border-radius: 50%; font-size: 32px; line-height: 1;
}
.lb-close { top: 12px; right: 12px; }
.lb-prev { left: 12px; top: 50%; margin-top: -26px; }
.lb-next { right: 12px; top: 50%; margin-top: -26px; }
@media (max-width: 639px) { .lb-prev, .lb-next { top: auto; bottom: 14px; margin-top: 0; } }

/* ---------- 6. Quote ---------- */
.quote { background: var(--white); }
.quote-grid {
  display: -ms-grid; display: grid;
  grid-template-columns: 1fr;
  grid-gap: 40px; gap: 40px;
}
@media (min-width: 1024px) { .quote-grid { grid-template-columns: 1.4fr 1fr; grid-gap: 56px; gap: 56px; -webkit-box-align: start; align-items: start; } }
.quote-intro { color: var(--muted); font-size: 18px; margin-bottom: 28px; }

.field-row { display: -ms-grid; display: grid; grid-template-columns: 1fr; grid-gap: 0 20px; gap: 0 20px; }
@media (min-width: 640px) { .field-row { grid-template-columns: 1fr 1fr; } }
.field { margin-bottom: 18px; }
.field label { display: block; font-weight: 600; margin-bottom: 6px; }
.field input, .field select, .field textarea {
  display: block; width: 100%; min-height: 50px;
  padding: 12px 14px;
  font: inherit; font-size: 16px; color: var(--text);
  background: var(--white);
  border: 2px solid #C9CDD3; border-radius: var(--radius);
  -webkit-appearance: none; -moz-appearance: none; appearance: none;
}
.field select {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'%3E%3Cpath fill='%23161616' d='M7 10l5 5 5-5z'/%3E%3C/svg%3E");
  background-repeat: no-repeat; background-position: right 10px center; background-size: 24px;
  padding-right: 40px;
}
.field textarea { resize: vertical; min-height: 130px; }
.field input:focus, .field select:focus, .field textarea:focus { border-color: var(--brand-dark); }
.field [aria-invalid="true"] { border-color: var(--error); background-color: #FFF6F6; }
.field-error { color: var(--error); font-size: 15px; font-weight: 600; margin: 6px 0 0; min-height: 0; }
.field-error:empty { display: none; }
.field-hint { color: var(--muted); font-size: 15px; margin: 6px 0 0; }
.form-note { color: var(--muted); font-size: 14px; margin-top: 12px; }
.hp { position: absolute !important; left: -10000px; width: 1px; height: 1px; overflow: hidden; }

.form-status { display: none; padding: 16px 18px; margin-bottom: 20px; border-radius: var(--radius); font-weight: 600; }
.form-status.is-success { display: block; background: #E8F5EC; color: var(--success); border-left: 6px solid var(--success); }
.form-status.is-error { display: block; background: #FDECEC; color: var(--error); border-left: 6px solid var(--error); }

.contact-card { background: var(--brand-dark); color: var(--white); padding: 32px 24px; border-radius: var(--radius); border-top: 6px solid var(--brand-primary); }
@media (min-width: 768px) { .contact-card { padding: 36px 32px; } }
.contact-card h3 { font-family: var(--font-display); font-weight: 800; text-transform: uppercase; font-size: 32px; }
.contact-list li { display: -webkit-box; display: -webkit-flex; display: flex; padding: 14px 0; border-bottom: 1px solid rgba(255,255,255,.1); }
.contact-list svg { width: 24px; height: 24px; margin-right: 14px; margin-top: 2px; color: var(--brand-primary); -webkit-flex-shrink: 0; flex-shrink: 0; }
.contact-list a { color: var(--white); text-decoration: none; font-weight: 600; display: inline-block; padding: 2px 0; word-break: break-word; }
.contact-list a:hover { color: var(--brand-primary); }
.c-label { display: block; font-size: 14px; color: rgba(255,255,255,.65); }
.hl { color: var(--brand-primary); }
.contact-card .btn { margin-top: 24px; }

.map-wrap { position: relative; margin-top: 24px; padding-top: 56.25%; border-radius: var(--radius); overflow: hidden; background: var(--dark-2); }
.map-wrap iframe { position: absolute; top: 0; left: 0; width: 100%; height: 100%; border: 0; }

/* ---------- 7. Footer ---------- */
.site-footer { background: #0D0D0D; color: rgba(255,255,255,.78); font-size: 16px; }
.footer-grid {
  display: -ms-grid; display: grid;
  grid-template-columns: 1fr;
  grid-gap: 32px; gap: 32px;
  padding-top: 56px; padding-bottom: 40px;
}
@media (min-width: 640px)  { .footer-grid { grid-template-columns: 1fr 1fr; } }
@media (min-width: 1024px) { .footer-grid { grid-template-columns: 1.6fr 1fr 1.2fr 1fr; } }
.footer-brand img { height: 56px; width: auto; margin-bottom: 16px; }
.footer-brand p { max-width: 36ch; }
.site-footer h4 { font-family: var(--font-display); font-weight: 700; text-transform: uppercase; font-size: 20px; color: var(--brand-primary); margin-bottom: 12px; }
.site-footer li { padding: 3px 0; }
.site-footer a { color: rgba(255,255,255,.85); text-decoration: none; display: inline-block; padding: 6px 0; }
.site-footer a:hover { color: var(--brand-primary); }
.footer-bottom { border-top: 4px solid var(--brand-primary); padding: 18px 0; font-size: 14px; }
.footer-bottom p { margin: 0; }
.footer-bottom a { color: var(--brand-primary); padding: 0; }

.back-to-top {
  position: fixed; right: 16px; bottom: 16px; z-index: 90;
  bottom: calc(16px + env(safe-area-inset-bottom, 0px));
  width: 50px; height: 50px;
  display: -webkit-box; display: -webkit-flex; display: flex;
  -webkit-box-align: center; -webkit-align-items: center; align-items: center;
  -webkit-box-pack: center; -webkit-justify-content: center; justify-content: center;
  background: var(--brand-primary); color: var(--brand-dark);
  border: 2px solid var(--brand-dark); border-radius: 50%;
  opacity: 0; visibility: hidden;
  -webkit-transition: opacity .25s, visibility .25s; transition: opacity .25s, visibility .25s;
}
.back-to-top.is-visible { opacity: 1; visibility: visible; }

/* ---------- Reduced motion ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { -webkit-animation: none !important; animation: none !important; -webkit-transition: none !important; transition: none !important; }
}