:root {
  --canvas: #ffffff;
  --surface: #f5f7f4;
  --surface-strong: #eef2ec;
  --ink: #171c1a;
  --ink-soft: #36413b;
  --muted: #65706a;
  --brand-green: #33cc33;
  --action-green: #168c1f;
  --action-green-hover: #0f7418;
  --brand-yellow: #ffcc00;
  --line: #dde4de;
  --line-strong: #c8d3ca;
  --shadow-soft: 0 10px 30px rgba(23, 28, 26, 0.08);
  --max: 1340px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; overflow-x: hidden; background: var(--canvas); color: var(--ink); font: 16px/1.65 Inter, Manrope, system-ui, -apple-system, "Segoe UI", sans-serif; }
img { display: block; max-width: 100%; height: auto; }
a { color: var(--action-green); }
a:visited { color: var(--action-green); }
a:hover { color: var(--action-green-hover); }
a:focus-visible, button:focus-visible { outline: 3px solid var(--brand-yellow); outline-offset: 4px; }
.skip { position: absolute; left: -999px; top: 8px; z-index: 100; padding: .7rem 1rem; background: var(--ink); color: #fff; }
.skip:focus { left: 8px; }
.wrap { width: min(calc(100% - 6rem), var(--max)); margin-inline: auto; }

.site-header { position: sticky; top: 0; z-index: 20; background: var(--canvas); border-bottom: 1px solid var(--line); }
.header-row { min-height: 94px; display: flex; align-items: center; gap: 2rem; }
.brand { display: inline-flex; flex: 0 0 235px; text-decoration: none; }
.brand img { width: 235px; height: auto; aspect-ratio: 440 / 160; object-fit: contain; }
.nav { margin-left: auto; }
.nav ul { display: flex; align-items: center; gap: clamp(1rem, 2vw, 2rem); margin: 0; padding: 0; list-style: none; }
.nav a { position: relative; padding-block: .55rem; color: var(--ink); text-decoration: none; font-size: .95rem; font-weight: 650; }
.nav a:visited { color: var(--ink); }
.nav a:not(.lang)::after { content: ""; position: absolute; right: 0; bottom: .15rem; left: 0; height: 2px; background: var(--brand-green); transform: scaleX(0); transition: transform .2s ease; }
.nav a:hover, .nav a[aria-current="page"] { color: var(--action-green); }
.nav a:hover::after, .nav a[aria-current="page"]::after { transform: scaleX(1); }
.lang { display: inline-block; min-width: 46px; padding: .3rem .7rem !important; text-align: center; border: 1px solid var(--brand-green); border-radius: 3px; }
.menu-toggle { display: none; margin-left: auto; padding: .55rem .8rem; background: var(--canvas); border: 1px solid var(--line-strong); border-radius: 3px; color: var(--ink); font: inherit; font-weight: 700; }

.home-hero { padding: 1rem 0; background: var(--surface); border-bottom: 1px solid var(--line); }
.home-hero-grid { min-height: 470px; display: grid; grid-template-columns: repeat(12, 1fr); align-items: center; gap: 2rem; }
.home-hero-copy { grid-column: span 5; padding-block: 3rem; }
.home-hero-visual { position: relative; grid-column: span 7; }
.home-hero-visual img { width: 100%; aspect-ratio: 16 / 9; object-fit: cover; border: 1px solid var(--brand-green); border-radius: 3px; }
.engineering-marker { position: absolute; right: 8%; top: 37%; width: 52px; height: 52px; border: 3px solid var(--brand-yellow); border-radius: 50%; }
.engineering-marker::after { content: ""; position: absolute; inset: 19px; background: var(--brand-yellow); border-radius: 50%; }
.eyebrow { color: var(--action-green); text-transform: uppercase; letter-spacing: .1em; font-weight: 800; font-size: .8rem; }
.home-hero h1 { max-width: 680px; margin: .5rem 0 1rem; font-size: clamp(2.6rem, 5vw, 4.8rem); line-height: 1.08; letter-spacing: -.035em; }
.home-hero p { max-width: 600px; margin: 0; color: var(--ink-soft); font-size: clamp(1rem, 1.4vw, 1.125rem); }
.hero-actions { display: flex; flex-wrap: wrap; align-items: center; gap: 1.75rem; margin-top: 1.7rem; }
.button { display: inline-block; margin-top: 1rem; padding: .78rem 1.2rem; background: var(--action-green); border: 1px solid var(--action-green); border-radius: 3px; color: #fff; text-decoration: none; font-weight: 800; }
.button:visited { color: #fff; }
.button:hover, .button:active { background: var(--action-green-hover); color: #fff; }
.hero-actions .button { margin-top: 0; }
.text-link { color: var(--ink); text-decoration: none; font-weight: 750; }
.text-link:visited { color: var(--ink); }
.text-link:hover { color: var(--action-green); }

/* Light, image-led heroes shared by all internal English and Bulgarian pages. */
.hero { position: relative; min-height: 330px; overflow: hidden; background: var(--surface); border-bottom: 1px solid var(--line); }
.hero-media { position: absolute; top: 0; right: 0; width: 50%; height: 100%; object-fit: cover; }
.hero-content { position: relative; z-index: 1; width: 50%; margin-left: max(3rem, calc((100% - var(--max)) / 2)); padding: 5rem 3rem 4rem 0; background: var(--surface); }
.hero h1 { margin: .45rem 0 1rem; font-size: clamp(2.6rem, 5vw, 4.2rem); line-height: 1.08; letter-spacing: -.03em; }
.hero p { max-width: 620px; color: var(--ink-soft); font-size: 1.125rem; }

.section { padding: 5.5rem 0; background: var(--canvas); }
.section.alt { background: var(--surface); }
.section-head { display: flex; justify-content: space-between; align-items: end; gap: 2rem; margin-bottom: 2.4rem; }
.section h2 { margin: .25rem 0; color: var(--ink); font-size: clamp(2rem, 3.4vw, 3.2rem); line-height: 1.15; }
.section-head p, .prose p, .prose li { max-width: 680px; color: var(--muted); }
.grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1.5rem; }
.grid.two { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.card { min-height: 190px; padding: 1.6rem; background: var(--canvas); border: 1px solid var(--line-strong); border-radius: 3px; }
.card h2, .card h3 { margin: .3rem 0 .65rem; color: var(--ink); }
.card h2 { font-size: 1.3rem; line-height: 1.25; }
.card h3 { font-size: 1.25rem; }
.card p { color: var(--muted); }
.card a.more, .timeline-panel .more { font-weight: 750; text-decoration: none; }
.media-card { overflow: hidden; padding: 0; transition: transform .2s ease, box-shadow .2s ease; }
.media-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-soft); }
.media-card img { width: 100%; aspect-ratio: 16 / 9; object-fit: cover; }
.media-card > div { padding: 1.5rem; }
.visual-card { overflow: hidden; }
.visual-card .card-image { width: calc(100% + 3.2rem); max-width: none; aspect-ratio: 16 / 9; margin: -1.6rem -1.6rem 1.25rem; object-fit: cover; border-bottom: 1px solid var(--line); }
.additional-areas { margin-top: 3.5rem; padding-top: 2.5rem; border-top: 1px solid var(--line); }
.additional-areas > p { max-width: 720px; color: var(--muted); }
.number { color: var(--action-green); font: 800 .8rem/1 monospace; letter-spacing: .1em; }
.prose { max-width: 850px; }
.prose h2 { margin-top: 2.5rem; }
.facts { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; background: var(--line); border: 1px solid var(--line); }
.fact { padding: 1.7rem; background: var(--canvas); }
.fact strong { display: block; color: var(--action-green); font-size: 1.35rem; }
.contact-grid { display: grid; grid-template-columns: 1.2fr .8fr; gap: 1.5rem; }
.contact-box { padding: 2rem; background: var(--canvas); border: 1px solid var(--line-strong); }
.contact-box address { color: var(--muted); font-style: normal; }
.notice { padding: 1rem 1.2rem; background: var(--surface); border-left: 3px solid var(--brand-green); color: var(--ink-soft); }

.process-section .section-head { margin-bottom: 1rem; }
.timeline { max-width: 940px; margin-inline: auto; border-left: 2px solid var(--line); }
.timeline-item { position: relative; border-bottom: 1px solid var(--line); }
.timeline-item h3 { margin: 0; }
.timeline-trigger { position: relative; width: 100%; display: grid; grid-template-columns: 3.5rem 1fr 1.5rem; gap: 1rem; align-items: start; padding: 1.35rem 1.5rem; background: transparent; border: 0; color: var(--ink); text-align: left; font: inherit; cursor: pointer; }
.timeline-trigger svg { width: 2.25rem; height: 2.25rem; padding: .45rem; background: var(--surface-strong); border: 1px solid var(--line-strong); border-radius: 50%; fill: none; stroke: var(--muted); stroke-width: 1.7; }
.timeline-trigger[aria-expanded="true"] svg { background: var(--brand-green); border-color: var(--brand-green); stroke: var(--ink); box-shadow: inset 0 0 0 10px var(--brand-green); }
.timeline-trigger[aria-expanded="true"]::before { content: ""; position: absolute; z-index: 1; left: 2.88rem; top: 2.24rem; width: 7px; height: 7px; border-radius: 50%; background: var(--brand-yellow); pointer-events: none; }
.timeline-trigger > span:nth-child(2) { position: relative; font-size: 1.18rem; font-weight: 750; }
.timeline-trigger small { display: block; margin-top: .35rem; color: var(--muted); font-size: .95rem; font-weight: 400; line-height: 1.5; }
.timeline-mark::before, .timeline-mark::after { content: ""; display: block; width: 14px; height: 2px; margin-top: 1rem; background: var(--ink-soft); }
.timeline-mark::after { margin-top: -2px; transform: rotate(90deg); transition: transform .2s; }
.timeline-trigger[aria-expanded="true"] .timeline-mark::after { transform: rotate(0); }
.timeline-trigger[aria-expanded="true"] { margin: .5rem; width: calc(100% - 1rem); border: 1px solid var(--line-strong); border-bottom: 0; }
.timeline-panel { margin: -.5rem .5rem .5rem; padding: 0 4rem 1.5rem 6rem; background: var(--canvas); border: 1px solid var(--line-strong); border-top: 0; color: var(--muted); }
.timeline-panel[hidden] { display: none; }
.timeline-panel p { max-width: 720px; margin-top: 0; }

.breadcrumbs { display: flex; flex-wrap: wrap; gap: .6rem; margin-bottom: 2rem; color: var(--muted); }
.detail-gallery { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1rem; margin: 2rem 0; }
.detail-gallery.single { grid-template-columns: minmax(0, 1fr); }
.detail-gallery img { width: 100%; aspect-ratio: 16 / 9; object-fit: cover; }
.detail-actions { display: flex; justify-content: space-between; align-items: center; gap: 1rem; margin-top: 2.5rem; }
.project-list { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1px; margin: 0; padding: 1px; background: var(--line); list-style: none; }
.project-list li { padding: 1.15rem 1.35rem; background: var(--canvas); color: var(--muted); }
.project-list li::before { content: ""; display: inline-block; width: .5rem; height: .5rem; margin-right: .7rem; background: var(--brand-green); border-radius: 50%; vertical-align: .08rem; }

.site-footer { padding: 3.5rem 0 2rem; background: var(--surface); border-top: 1px solid var(--line); color: var(--muted); }
.site-footer .brand { margin-bottom: 1rem; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 3rem; }
.footer-grid strong { color: var(--ink); }
.footer-nav { margin: .5rem 0 0; padding: 0; list-style: none; }
.footer-nav a { color: var(--action-green); }
.copyright { margin-top: 2rem; padding-top: 1.4rem; border-top: 1px solid var(--line); font-size: .87rem; }

@media (max-width: 1100px) {
  .wrap { width: min(calc(100% - 3rem), var(--max)); }
  .header-row { min-height: 84px; }
  .brand { flex-basis: 205px; }
  .brand img { width: 205px; }
  .menu-toggle { display: block; }
  .nav { display: none; position: absolute; top: 84px; right: 0; left: 0; padding: 1rem 1.5rem; background: var(--canvas); border-bottom: 1px solid var(--line); box-shadow: var(--shadow-soft); }
  .nav.open { display: block; }
  .nav ul { align-items: stretch; flex-direction: column; gap: .2rem; }
  .nav a { display: block; padding: .55rem; }
  .lang { width: 100%; }
  .grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .home-hero-grid { min-height: 0; }
  .home-hero-copy, .home-hero-visual { grid-column: span 6; }
  .home-hero h1 { font-size: clamp(2.5rem, 5vw, 3.7rem); }
}

@media (max-width: 760px) {
  .wrap { width: min(calc(100% - 2.5rem), var(--max)); }
  .home-hero { padding: 2.5rem 0 3rem; }
  .home-hero-grid { display: flex; flex-direction: column; align-items: stretch; gap: 2rem; }
  .home-hero-copy { padding: 0; }
  .engineering-marker { display: none; }
  .hero { min-height: 0; display: flex; flex-direction: column-reverse; }
  .hero-media { position: static; width: 100%; height: auto; aspect-ratio: 16 / 7; }
  .hero-content { width: min(calc(100% - 2.5rem), var(--max)); margin-inline: auto; padding: 3rem 0; }
  .section { padding: 3.75rem 0; }
  .section-head { display: block; }
  .grid, .grid.two, .facts, .contact-grid, .footer-grid { grid-template-columns: 1fr; }
  .card { min-height: 0; }
  .timeline { border-left: 0; }
  .timeline-trigger { grid-template-columns: 2.8rem 1fr 1rem; padding: 1.1rem .6rem; }
  .timeline-trigger[aria-expanded="true"] { margin-inline: 0; width: 100%; }
  .timeline-trigger[aria-expanded="true"]::before { left: 1.98rem; top: 1.99rem; }
  .timeline-panel { margin-inline: 0; padding: 0 1rem 1.4rem 4.4rem; }
  .project-list, .detail-gallery { grid-template-columns: 1fr; }
  .detail-actions { align-items: flex-start; flex-direction: column; }
}

@media (max-width: 480px) {
  .header-row { min-height: 78px; gap: .75rem; }
  .brand { flex-basis: 175px; }
  .brand img { width: 175px; }
  .nav { top: 78px; }
  .home-hero h1 { font-size: 2.55rem; }
  .hero-actions { align-items: stretch; flex-direction: column; gap: 1rem; }
  .hero-actions .button { width: 100%; text-align: center; }
  .timeline-trigger small { display: none; }
}

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