/* Oxford Engineering – single stylesheet */
:root {
  --red: #ef172f;
  --red-dark: #c80f24;
  --ink: #18171a;
  --charcoal: #231f1e;
  --graphite: #2e2b2b;
  --steel: #f3f3f1;
  --line: #e2e1de;
  --text: #2a2828;
  --muted: #605c5b;
  --white: #fff;
  --radius: 4px;
  --maxw: 1200px;
  --head: "Archivo", "Arial Narrow", Arial, sans-serif;
  --body: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 80px; -webkit-text-size-adjust: 100%; }
body { margin: 0; font-family: var(--body); font-size: 1.0625rem; line-height: 1.65; color: var(--text); background: var(--white); }
img { max-width: 100%; height: auto; display: block; }
a { color: var(--red-dark); }
a:hover { color: var(--red); }
h1, h2, h3 { font-family: var(--head); line-height: 1.12; color: var(--ink); margin: 0 0 .6em; letter-spacing: -0.01em; }
h1 { font-size: clamp(2.4rem, 6vw, 4.4rem); font-weight: 800; }
h2 { font-size: clamp(1.8rem, 3.6vw, 2.7rem); font-weight: 800; }
h3 { font-size: 1.25rem; font-weight: 700; }
p { margin: 0 0 1.1em; }
address { font-style: normal; }
:focus-visible { outline: 3px solid var(--red); outline-offset: 3px; }

.container { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 1.5rem; }
.visually-hidden { position: absolute !important; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.skip-link { position: absolute; left: 1rem; top: -100px; background: var(--red); color: #fff; padding: .6rem 1rem; z-index: 100; }
.skip-link:focus { top: 1rem; color: #fff; }

.eyebrow { font-family: var(--head); font-weight: 700; font-size: .85rem; letter-spacing: .14em; text-transform: uppercase; color: var(--red); margin-bottom: .8rem; display: flex; align-items: center; gap: .6rem; }
.eyebrow::before { content: ""; width: 12px; height: 12px; background: var(--red); box-shadow: inset 0 0 0 3.5px var(--red), inset 0 0 0 12px #fff; flex: none; }

/* Buttons */
.btn-row { display: flex; flex-wrap: wrap; gap: .9rem; margin-top: 1.6rem; }
.btn { display: inline-flex; align-items: center; justify-content: center; gap: .55rem; min-height: 52px; padding: .8rem 1.6rem; font-family: var(--head); font-weight: 700; font-size: 1rem; letter-spacing: .03em; text-transform: uppercase; text-decoration: none; border-radius: var(--radius); border: 2px solid transparent; transition: background .2s, color .2s, border-color .2s; }
.btn svg { width: 20px; height: 20px; fill: currentColor; }
.btn-primary { background: var(--red); color: #fff; }
.btn-primary:hover { background: var(--red-dark); color: #fff; }
.btn-outline { border-color: currentColor; color: #fff; background: transparent; }
.btn-outline:hover { background: #fff; color: var(--ink); border-color: #fff; }

/* Header */
.site-header { position: sticky; top: 0; z-index: 50; background: rgba(24, 23, 26, .97); border-bottom: 3px solid var(--red); }
.header-inner { display: flex; align-items: center; justify-content: space-between; min-height: 76px; }
.brand img { width: 190px; }
.site-nav ul { list-style: none; margin: 0; padding: 0; display: flex; align-items: center; gap: 2rem; }
.site-nav a { color: #fff; text-decoration: none; font-family: var(--head); font-weight: 600; font-size: .95rem; letter-spacing: .06em; text-transform: uppercase; }
.site-nav a:hover { color: var(--red); }
.site-nav .nav-phone { background: var(--red); padding: .6rem 1rem; border-radius: var(--radius); }
.site-nav .nav-phone:hover { background: var(--red-dark); color: #fff; }
.nav-toggle { display: none; background: none; border: 0; width: 48px; height: 48px; cursor: pointer; position: relative; }
.nav-toggle-bar, .nav-toggle-bar::before, .nav-toggle-bar::after { position: absolute; left: 12px; width: 24px; height: 2px; background: #fff; content: ""; transition: transform .2s, opacity .2s; }
.nav-toggle-bar { top: 23px; }
.nav-toggle-bar::before { left: 0; top: -8px; }
.nav-toggle-bar::after { left: 0; top: 8px; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bar { background: transparent; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bar::before { transform: translateY(8px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-bar::after { transform: translateY(-8px) rotate(-45deg); }

/* Hero */
.hero { position: relative; min-height: min(88vh, 760px); display: flex; align-items: center; color: #fff; overflow: hidden; background: var(--ink); }
.hero-bg { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; object-position: 70% 30%; }
.hero::after { content: ""; position: absolute; inset: 0; z-index: 1; background: linear-gradient(90deg, rgba(16,15,17,.78) 0%, rgba(16,15,17,.6) 35%, rgba(16,15,17,.15) 60%, rgba(16,15,17,0) 80%); }
.hero-content { position: relative; z-index: 2; padding-top: 4rem; padding-bottom: 4rem; }
.hero h1 { color: #fff; max-width: 13ch; }
.hero-lead { font-size: clamp(1.1rem, 1.6vw, 1.3rem); max-width: 40ch; color: #e7e5e3; }
.hero .eyebrow { color: #fff; }

/* Sections */
.section { padding: clamp(4rem, 8vw, 6.5rem) 0; }
.section-head { max-width: 680px; margin-bottom: 2.8rem; }
.section-intro { color: var(--muted); font-size: 1.125rem; }

/* Services */
.services { background: var(--steel); }
.service-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.5rem; }
.service-card { background: #fff; padding: 2rem 1.8rem; border-top: 4px solid var(--charcoal); border-radius: var(--radius); box-shadow: 0 1px 2px rgba(0,0,0,.05); transition: border-color .2s, transform .2s; }
.service-card:hover { border-top-color: var(--red); transform: translateY(-3px); }
.service-num { display: block; font-family: var(--head); font-weight: 800; font-size: .95rem; color: var(--red); margin-bottom: .9rem; letter-spacing: .08em; }
.service-card p { color: var(--muted); margin: 0; }

/* About */
.about-grid { display: grid; grid-template-columns: 1fr 1fr; gap: clamp(2rem, 5vw, 4.5rem); align-items: center; }
.about-media { position: relative; }
.about-media img { width: 100%; aspect-ratio: 4 / 3.4; object-fit: cover; border-radius: var(--radius); }
.about-media::before { content: ""; position: absolute; left: -14px; bottom: -14px; width: 40%; height: 40%; background: var(--red); z-index: -1; }
.about { position: relative; z-index: 0; }
.check-list { list-style: none; padding: 0; margin: 1.5rem 0 2rem; }
.check-list li { position: relative; padding-left: 2rem; margin-bottom: .8rem; }
.check-list li::before { content: ""; position: absolute; left: 0; top: .45em; width: 14px; height: 14px; background: var(--red); box-shadow: inset 0 0 0 4px var(--red), inset 0 0 0 14px #fff; }
.check-list strong { color: var(--ink); }

/* Gallery */
.gallery { background: var(--ink); }
.gallery h2 { color: #fff; }
.gallery-grid { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(4, 1fr); grid-auto-rows: 240px; grid-auto-flow: dense; gap: 10px; }
.gallery-grid li { overflow: hidden; border-radius: var(--radius); background: var(--graphite); }
.gallery-grid .g-wide { grid-column: span 2; }
.gallery-grid a { display: block; height: 100%; }
.gallery-grid img { width: 100%; height: 100%; object-fit: cover; transition: transform .4s, opacity .3s; }
.gallery-grid a:hover img, .gallery-grid a:focus-visible img { transform: scale(1.04); opacity: .9; }

.lightbox { border: 0; padding: 0; background: transparent; max-width: 94vw; max-height: 92vh; }
.lightbox::backdrop { background: rgba(10,10,12,.9); }
.lightbox img { max-width: 94vw; max-height: 88vh; object-fit: contain; margin: auto; }
.lightbox-close { position: fixed; top: 12px; right: 16px; width: 48px; height: 48px; border: 0; background: var(--red); color: #fff; font-size: 2rem; line-height: 1; cursor: pointer; border-radius: var(--radius); }

/* Contact */
.contact { background: var(--steel); }
.contact-grid { display: grid; grid-template-columns: 1.15fr 1fr; gap: clamp(2rem, 5vw, 4rem); align-items: start; }
.contact .btn-outline { color: var(--ink); }
.contact .btn-outline:hover { background: var(--ink); color: #fff; border-color: var(--ink); }
.contact-list { list-style: none; margin: 0; padding: 2rem; background: var(--charcoal); color: #fff; border-radius: var(--radius); border-left: 6px solid var(--red); }
.contact-list li { padding: 1.1rem 0; border-bottom: 1px solid rgba(255,255,255,.12); }
.contact-list li:first-child { padding-top: 0; }
.contact-list li:last-child { border-bottom: 0; padding-bottom: 0; }
.contact-label { display: block; font-family: var(--head); font-weight: 700; font-size: .8rem; letter-spacing: .14em; text-transform: uppercase; color: #bdb8b6; margin-bottom: .25rem; }
.contact-list a { color: #fff; font-size: 1.2rem; font-weight: 600; text-decoration: none; overflow-wrap: anywhere; }
.contact-list a:hover { color: var(--red); }
.contact-list address { font-size: 1.15rem; font-weight: 500; }
.contact-list .map-link { display: inline-block; margin-top: .5rem; font-size: .95rem; font-weight: 500; text-decoration: underline; color: #e7e5e3; }

/* Footer */
.site-footer { background: var(--ink); color: #b9b5b3; padding: 3rem 0; font-size: .95rem; border-top: 3px solid var(--red); }
.footer-inner { display: grid; grid-template-columns: auto 1fr; gap: .5rem 2.5rem; align-items: center; }
.footer-logo { width: 170px; grid-row: span 2; }
.site-footer p { margin: 0; }
.footer-legal { font-size: .85rem; color: #8f8a88; }


/* At a glance (entity facts) */
.facts { margin-top: clamp(3rem, 6vw, 4.5rem); padding: 2rem; background: var(--steel); border-left: 6px solid var(--red); border-radius: var(--radius); }
.facts-title { font-size: 1.15rem; margin-bottom: .6rem; }
.facts-summary { color: var(--muted); max-width: 80ch; }
.facts-list { margin: 1.4rem 0 0; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1.2rem 2rem; }
.facts-list div { border-top: 1px solid var(--line); padding-top: .8rem; }
.facts-list dt { font-family: var(--head); font-weight: 700; font-size: .78rem; letter-spacing: .14em; text-transform: uppercase; color: var(--red-dark); margin-bottom: .25rem; }
.facts-list dd { margin: 0; font-size: .97rem; color: var(--text); overflow-wrap: anywhere; }

/* FAQ */
.faq-grid { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1.6fr); gap: clamp(2rem, 5vw, 4rem); align-items: start; }
.faq-grid .section-head { margin-bottom: 0; position: sticky; top: 110px; }
.faq-list { border-top: 1px solid var(--line); }
.faq-item { border-bottom: 1px solid var(--line); }
.faq-item summary { list-style: none; cursor: pointer; display: flex; align-items: center; justify-content: space-between; gap: 1.5rem; padding: 1.3rem 0; }
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary h3 { margin: 0; font-size: 1.12rem; }
.faq-item summary::after { content: "+"; flex: none; width: 34px; height: 34px; display: grid; place-items: center; background: var(--charcoal); color: #fff; font-family: var(--head); font-weight: 700; font-size: 1.3rem; border-radius: var(--radius); transition: background .2s; }
.faq-item[open] summary::after { content: "\2212"; background: var(--red); }
.faq-item summary:hover h3 { color: var(--red-dark); }
.faq-answer { padding: 0 3.5rem 1.4rem 0; color: var(--muted); }
.faq-answer p { margin: 0; }

/* 404 */
.notfound { min-height: 70vh; display: flex; align-items: center; background: var(--ink); color: #e7e5e3; text-align: left; }
.notfound h1 { color: #fff; }
.notfound .btn-row { margin-top: 2rem; }

@media (max-width: 860px) {
  .facts-list { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .faq-grid { grid-template-columns: 1fr; }
  .faq-grid .section-head { position: static; }
}
@media (max-width: 600px) {
  .facts { padding: 1.5rem 1.25rem; }
  .facts-list { grid-template-columns: 1fr; }
  .faq-answer { padding-right: 0; }
  .faq-item summary h3 { font-size: 1.02rem; }
}

/* Responsive */
@media (max-width: 1000px) {
  .service-grid { grid-template-columns: repeat(2, 1fr); }
  .gallery-grid { grid-template-columns: repeat(3, 1fr); grid-auto-rows: 210px; }
}
@media (max-width: 860px) {
  .nav-toggle { display: block; }
  .site-nav { position: absolute; top: 100%; left: 0; right: 0; background: var(--ink); border-bottom: 3px solid var(--red); display: none; }
  .site-nav.is-open { display: block; }
  .site-nav ul { flex-direction: column; align-items: stretch; gap: 0; padding: .5rem 1.5rem 1.5rem; }
  .site-nav li a { display: block; padding: 1rem 0; border-bottom: 1px solid rgba(255,255,255,.1); }
  .site-nav .nav-phone { margin-top: 1rem; text-align: center; border-bottom: 0; }
  .about-grid, .contact-grid { grid-template-columns: 1fr; }
  .about-media::before { left: -10px; bottom: -10px; }
  .footer-inner { grid-template-columns: 1fr; }
  .footer-logo { grid-row: auto; margin-bottom: .5rem; }
}
@media (max-width: 600px) {
  body { font-size: 1rem; }
  .brand img { width: 150px; }
  .header-inner { min-height: 66px; }
  .hero { min-height: auto; }
  .hero-bg { object-position: 72% center; }
  .hero::after { background: linear-gradient(180deg, rgba(16,15,17,.5) 0%, rgba(16,15,17,.68) 40%, rgba(16,15,17,.8) 100%); }
  .hero-content { padding-top: 4.5rem; padding-bottom: 4.5rem; }
  .btn-row .btn { width: 100%; }
  .service-grid { grid-template-columns: 1fr; }
  .gallery-grid { grid-template-columns: repeat(2, 1fr); grid-auto-rows: 160px; gap: 8px; }
  .contact-list { padding: 1.4rem 1.25rem; }
  .contact-list a { font-size: 1.05rem; }
  .contact-list a[href^="mailto"] { font-size: .98rem; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; }
}

/* 3D stair model */
.stair-section { background: var(--steel); overflow: hidden; }
.stair-grid { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1.55fr); gap: clamp(2rem, 5vw, 4rem); align-items: center; }
.stair-caption { font-size: 1.125rem; color: var(--text); }
.stair-note { font-size: .9rem; color: var(--muted); }
.stair-figure { margin: 0; }
.stair3d { position: relative; aspect-ratio: 16 / 10; max-height: 580px; width: 100%; border-radius: var(--radius); background: radial-gradient(ellipse at 50% 45%, #fff 0%, var(--steel) 70%, #e9e8e5 100%); border: 1px solid var(--line); border-bottom: 4px solid var(--charcoal); overflow: hidden; }
.stair3d-fallback { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: contain; transition: opacity .4s; }
.stair3d-canvas { position: absolute; inset: 0; width: 100% !important; height: 100% !important; display: block; cursor: grab; outline: none; }
.stair3d-canvas:active { cursor: grabbing; }
.stair3d[data-state="ready"] .stair3d-fallback { opacity: 0; pointer-events: none; }
.stair3d-msg { position: absolute; left: 1rem; right: 1rem; bottom: 1rem; margin: 0; padding: .6rem .9rem; background: rgba(35, 31, 30, .88); color: #fff; font-size: .9rem; border-radius: var(--radius); }
.stair3d-toggle { position: absolute; right: .75rem; top: .75rem; min-height: 40px; padding: .4rem .9rem; font-family: var(--head); font-weight: 700; font-size: .8rem; letter-spacing: .06em; text-transform: uppercase; color: #fff; background: var(--charcoal); border: 0; border-radius: var(--radius); cursor: pointer; }
.stair3d-toggle:hover { background: var(--red); }
.stair-hint { margin-top: .7rem; font-size: .9rem; color: var(--muted); text-align: center; }

@media (min-width: 861px) and (max-width: 1140px) {
  .site-nav ul { gap: 1.1rem; }
  .site-nav a { font-size: .85rem; letter-spacing: .04em; }
}
@media (max-width: 860px) {
  .stair-grid { grid-template-columns: 1fr; }
}
@media (max-width: 600px) {
  .stair3d { aspect-ratio: 1 / 1; max-height: 70vh; }
}


/* Hero text entrance (CSS only, so content shows with JS off; static for reduced motion). */
@media (prefers-reduced-motion: no-preference) {
  .hero .eyebrow, .hero h1, .hero-lead, .hero .btn-row .btn { animation: hero-rise .6s cubic-bezier(.2, .7, .2, 1) both; }
  .hero h1 { animation-delay: .08s; animation-duration: .45s; }
  .hero-lead { animation-delay: .23s; }
  .hero .btn-row .btn:nth-child(1) { animation-delay: .36s; }
  .hero .btn-row .btn:nth-child(2) { animation-delay: .48s; }
  .hero .eyebrow { position: relative; width: fit-content; animation: hero-label-text .9s steps(1, end) both; }
  .hero .eyebrow::after { content: ""; position: absolute; left: 0; top: 0; bottom: 0; width: 100%; background: var(--red); transform: scaleX(0); transform-origin: left center; animation: hero-wipe .9s cubic-bezier(.7, 0, .3, 1) both; }
}
@keyframes hero-rise { from { opacity: 0; transform: translateY(22px); } to { opacity: 1; transform: none; } }
@keyframes hero-label-text { 0% { color: transparent; } 50% { color: #fff; } }
@keyframes hero-wipe {
  0% { transform: scaleX(0); transform-origin: left center; }
  50% { transform: scaleX(1); transform-origin: left center; }
  50.1% { transform: scaleX(1); transform-origin: right center; }
  100% { transform: scaleX(0); transform-origin: right center; }
}