:root {
  color-scheme: light;
  --ink: #132831;
  --ink-soft: #24414a;
  --paper: #f4f7f6;
  --surface: #ffffff;
  --line: #d7e0df;
  --teal: #0d6964;
  --teal-dark: #084b49;
  --orange: #d85d28;
  --green: #168367;
  --muted: #61737a;
  --max: 1180px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--paper); color: var(--ink); font: 15px/1.65 system-ui, -apple-system, "Segoe UI", "Microsoft YaHei", sans-serif; overflow-wrap: break-word; }
img { display: block; max-width: 100%; }
a { color: inherit; }
.shell { width: min(calc(100% - 56px), var(--max)); margin: 0 auto; }
.site-header { position: absolute; z-index: 10; top: 0; left: 50%; display: flex; width: min(calc(100% - 56px), var(--max)); height: 78px; transform: translateX(-50%); align-items: center; justify-content: space-between; gap: 24px; border-bottom: 1px solid rgba(255,255,255,.28); color: #fff; }
.brand { display: inline-flex; align-items: center; gap: 11px; text-decoration: none; }
.brand-mark { display: grid; place-items: center; width: 40px; height: 40px; border-radius: 6px; background: var(--orange); color: #fff; font-size: 17px; font-weight: 850; }
.brand-copy { display: grid; line-height: 1.15; }
.brand-copy strong { font-size: 18px; }
.brand-copy small { color: rgba(255,255,255,.72); font-size: 11px; }
.header-actions, .language { display: flex; align-items: center; gap: 12px; }
.language { color: rgba(255,255,255,.78); font-size: 12px; }
.language select { min-height: 36px; border: 1px solid rgba(255,255,255,.38); border-radius: 4px; background: rgba(19,40,49,.72); padding: 5px 28px 5px 9px; color: #fff; font: inherit; }
.header-link { min-height: 36px; display: inline-flex; align-items: center; padding: 5px 13px; border: 1px solid rgba(255,255,255,.48); border-radius: 4px; text-decoration: none; font-weight: 750; }

.hero { position: relative; height: min(720px, calc(100svh - 86px)); min-height: 580px; overflow: hidden; background: var(--ink); color: #fff; }
.hero-image, .hero-overlay { position: absolute; inset: 0; }
.hero-image { background: url('/products/dilucalc/assets/hero-railway-track.jpg') center 45% / cover no-repeat; transform: scale(1.01); }
.hero-overlay { background: rgba(10,31,39,.72); }
.hero-content { position: relative; z-index: 2; display: flex; height: 100%; flex-direction: column; align-items: flex-start; justify-content: center; padding-top: 70px; }
.eyebrow { margin: 0 0 17px; color: #ff9b70; font-size: 12px; font-weight: 850; letter-spacing: 0; }
.eyebrow.dark { color: var(--teal); }
h1, h2, h3, p { margin-top: 0; }
h1 { max-width: 760px; margin-bottom: 18px; font-size: 68px; line-height: 1.04; letter-spacing: 0; }
.hero-lead { max-width: 720px; margin-bottom: 31px; color: rgba(255,255,255,.82); font-size: 19px; line-height: 1.75; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 11px; }
.button { display: inline-flex; min-height: 48px; align-items: center; justify-content: center; gap: 9px; border: 1px solid transparent; border-radius: 4px; padding: 10px 18px; text-decoration: none; font-weight: 800; }
.button svg, .text-link svg, .download-link svg, .release-badge svg { width: 17px; height: 17px; flex: 0 0 auto; }
.button.primary { background: var(--orange); color: #fff; }
.button.primary:hover { background: #bd4820; }
.button.ghost { border-color: rgba(255,255,255,.5); background: rgba(19,40,49,.36); color: #fff; }
.button.ghost:hover { background: rgba(19,40,49,.62); }

.release-strip { background: var(--ink); color: #fff; }
.release-grid { display: grid; grid-template-columns: repeat(3, 1fr); }
.release-item { min-height: 108px; display: grid; align-content: center; gap: 3px; padding: 22px 28px; border-left: 1px solid rgba(255,255,255,.14); }
.release-item:last-child { border-right: 1px solid rgba(255,255,255,.14); }
.release-item strong { color: #ff9b70; font-size: 25px; line-height: 1.15; }
.release-item span { color: rgba(255,255,255,.68); font-size: 12px; }

.released { padding: 96px 0 104px; }
.section-heading { display: grid; grid-template-columns: 1fr minmax(320px, 520px); gap: 56px; align-items: end; margin-bottom: 34px; }
.section-heading.compact { display: block; margin-bottom: 30px; }
.section-heading h2, .building h2 { margin-bottom: 0; font-size: 42px; line-height: 1.12; letter-spacing: 0; }
.section-heading > p { margin-bottom: 3px; color: var(--muted); }
.product-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 20px; }
.product-card { min-width: 0; overflow: hidden; border: 1px solid var(--line); border-radius: 6px; background: var(--surface); }
.product-media { position: relative; display: block; aspect-ratio: 16 / 9; overflow: hidden; background: #dce5e5; }
.product-media img { width: 100%; height: 100%; object-fit: cover; transition: transform .3s ease; }
.product-card:hover .product-media img { transform: scale(1.025); }
.media-label { position: absolute; left: 16px; bottom: 16px; padding: 6px 9px; background: rgba(19,40,49,.9); color: #fff; font-size: 10px; font-weight: 850; letter-spacing: 0; }
.product-body { padding: 24px; }
.product-topline { display: flex; align-items: center; justify-content: space-between; gap: 14px; color: var(--muted); font-size: 12px; font-weight: 750; }
.release-badge { display: inline-flex; align-items: center; gap: 6px; color: var(--green); }
.product-body h3 { margin: 13px 0 7px; font-size: 30px; line-height: 1.15; letter-spacing: 0; }
.product-body > p { min-height: 50px; margin-bottom: 23px; color: var(--muted); }
.product-actions { display: flex; align-items: center; justify-content: space-between; gap: 16px; border-top: 1px solid var(--line); padding-top: 18px; }
.text-link, .download-link { display: inline-flex; align-items: center; gap: 7px; color: var(--teal); text-decoration: none; font-weight: 800; }
.download-link { color: var(--ink); font-size: 13px; }
.text-link:hover, .download-link:hover { color: var(--orange); }

.building { border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); background: #e9efed; }
.building-layout { min-height: 230px; display: grid; grid-template-columns: .8fr 1.5fr auto; align-items: center; gap: 54px; }
.building-layout p { margin-bottom: 0; color: var(--muted); }
.principles { padding: 88px 0 100px; background: var(--surface); }
.principle-grid { display: grid; grid-template-columns: repeat(3, 1fr); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.principle-grid article { min-height: 210px; padding: 30px; border-left: 1px solid var(--line); }
.principle-grid article:last-child { border-right: 1px solid var(--line); }
.principle-grid svg { width: 25px; height: 25px; color: var(--orange); }
.principle-grid h3 { margin: 34px 0 8px; font-size: 19px; }
.principle-grid p { margin-bottom: 0; color: var(--muted); }
.footer { background: var(--ink); color: rgba(255,255,255,.65); }
.footer-inner { min-height: 92px; display: flex; align-items: center; justify-content: space-between; gap: 24px; font-size: 12px; }
.footer a { text-decoration: none; }

@media (max-width: 900px) {
  h1 { font-size: 52px; }
  .section-heading { grid-template-columns: 1fr; gap: 16px; }
  .building-layout { grid-template-columns: 1fr; gap: 18px; padding: 50px 0; }
}

@media (max-width: 700px) {
  .shell, .site-header { width: calc(100% - 28px); }
  .site-header { height: 64px; }
  .brand-mark { width: 36px; height: 36px; }
  .brand-copy strong { font-size: 16px; }
  .brand-copy small, .language > span, .header-link { display: none; }
  .language select { min-height: 34px; }
  .hero { height: min(690px, calc(100svh - 68px)); min-height: 570px; }
  .hero-content { padding-top: 56px; }
  h1 { font-size: 40px; }
  .hero-lead { font-size: 16px; line-height: 1.65; }
  .hero-actions { display: grid; width: 100%; }
  .button { width: 100%; }
  .release-grid { grid-template-columns: 1fr; padding: 10px 0; }
  .release-item { min-height: 74px; grid-template-columns: 120px 1fr; align-items: center; padding: 14px 0; border-left: 0; border-bottom: 1px solid rgba(255,255,255,.14); }
  .release-item:last-child { border-right: 0; border-bottom: 0; }
  .release-item strong { font-size: 20px; }
  .released { padding: 68px 0 72px; }
  .section-heading h2, .building h2 { font-size: 34px; }
  .product-grid { grid-template-columns: 1fr; gap: 16px; }
  .product-body { padding: 20px; }
  .product-body > p { min-height: auto; }
  .product-actions { align-items: flex-start; flex-direction: column; }
  .principles { padding: 66px 0 70px; }
  .principle-grid { grid-template-columns: 1fr; }
  .principle-grid article { min-height: auto; border-left: 0; border-bottom: 1px solid var(--line); padding: 25px 0; }
  .principle-grid article:last-child { border-right: 0; border-bottom: 0; }
  .principle-grid h3 { margin-top: 18px; }
  .footer-inner { min-height: 112px; flex-direction: column; align-items: flex-start; justify-content: center; gap: 7px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .product-media img { transition: none; }
}