:root {
  --bg: #ffffff;
  --ink: #111719;
  --muted: #687477;
  --line: #dbe5e4;
  --soft: #f4f7f6;
  --soft-2: #edf3f2;
  --accent: #00565e;
  --accent-dark: #004950;
  --orange: #ee7201;
  --panel: #ffffff;
  --shadow: 0 24px 70px rgba(0, 86, 94, 0.12);
  --radius: 8px;
  --max: 1180px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: Inter, Arial, sans-serif;
  line-height: 1.55;
  overflow-x: hidden;
}

main {
  overflow: hidden;
}

img {
  display: block;
  max-width: 100%;
}

a {
  color: inherit;
  text-decoration: none;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 28px;
  width: 100%;
  max-width: none;
  margin: 0 auto;
  padding: 22px max(40px, calc((100vw - var(--max)) / 2));
  background: rgba(255, 255, 255, 0.96);
  border-bottom: 1px solid rgba(217, 226, 231, 0.7);
  backdrop-filter: blur(16px);
  box-shadow: 0 10px 34px rgba(0, 86, 94, 0.05);
}

.brand {
  display: inline-flex;
  align-items: center;
  width: auto;
}

.brand-logo {
  color: #5e6163;
  font-size: 29px;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: lowercase;
}

.brand-logo span {
  color: var(--accent);
}

.site-nav {
  display: flex;
  justify-content: center;
  gap: 28px;
  color: #40505a;
  font-size: 14px;
  font-weight: 600;
}

.site-nav a:hover,
.site-footer a:hover {
  color: var(--accent);
}

.header-cta,
.button {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  padding: 0 20px;
  border: 1px solid transparent;
  border-radius: 7px;
  font-size: 14px;
  font-weight: 700;
  cursor: pointer;
  transition: transform 0.2s ease, background 0.2s ease, border 0.2s ease;
}

.header-cta,
.button.primary {
  color: white;
  background: var(--accent);
}

.button.secondary {
  color: var(--ink);
  background: white;
  border-color: var(--line);
}

.header-cta:hover,
.button:hover {
  transform: translateY(-1px);
}

.header-cta:hover,
.button.primary:hover {
  background: var(--orange);
}

.menu-toggle {
  display: none;
}

.section {
  width: min(calc(100% - 40px), var(--max));
  max-width: var(--max);
  margin: 0 auto;
}

.hero {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 0.86fr) minmax(380px, 0.95fr);
  gap: 46px;
  align-items: center;
  min-height: calc(100vh - 90px);
  padding: 18px 0 42px;
}

.scroll-cue {
  position: absolute;
  left: 50%;
  bottom: 28px;
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 700;
  transform: translateX(-50%);
}

.scroll-cue i {
  display: grid;
  width: 42px;
  height: 42px;
  place-items: center;
  border: 1px solid var(--line);
  border-radius: 50%;
}

.scroll-cue i::before {
  width: 8px;
  height: 8px;
  border-right: 2px solid var(--accent);
  border-bottom: 2px solid var(--accent);
  content: "";
  transform: rotate(45deg) translate(-1px, -2px);
}

.hero-copy h1 {
  max-width: 560px;
  margin: 0;
  font-size: clamp(34px, 4.1vw, 56px);
  line-height: 1.05;
  font-weight: 800;
  letter-spacing: 0;
}

.hero-copy p {
  max-width: 520px;
  margin: 24px 0 0;
  color: var(--muted);
  font-size: 18px;
}

.hero-note {
  display: grid;
  grid-template-columns: minmax(180px, 0.72fr) 1fr;
  gap: 24px;
  max-width: 760px;
  margin-top: 34px;
  padding-top: 24px;
  border-top: 1px solid var(--line);
}

.hero-note h2 {
  font-size: 24px;
  line-height: 1.1;
}

.hero-note p {
  margin: 0;
  font-size: 15px;
  line-height: 1.55;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 34px;
}

.hero-media {
  position: relative;
  min-height: 420px;
  overflow: hidden;
  border-radius: 0 0 0 var(--radius);
  background: var(--soft);
  box-shadow: 0 28px 84px rgba(0, 86, 94, 0.12);
}

.hero-media img {
  width: 100%;
  height: 420px;
  object-fit: cover;
}

.hero-videos {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  grid-template-rows: none;
  gap: 12px;
  padding: 12px;
  background: var(--soft);
}

.compact-videos {
  align-self: center;
}

.video-card {
  position: relative;
  display: block;
  min-height: 220px;
  overflow: hidden;
  border-radius: 7px;
  background: #dce7eb;
}

.video-card img {
  width: 100%;
  height: 100%;
  min-height: 220px;
  object-fit: cover;
  transition: transform 0.25s ease;
}

.video-card::after {
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(10, 20, 25, 0.08), rgba(10, 20, 25, 0.34));
  content: "";
}

.video-card:hover img {
  transform: scale(1.03);
}

.play-button {
  position: absolute;
  left: 50%;
  top: 50%;
  z-index: 2;
  display: grid;
  width: 56px;
  height: 56px;
  place-items: center;
  background: rgba(255, 255, 255, 0.92);
  border-radius: 50%;
  box-shadow: 0 18px 44px rgba(15, 32, 40, 0.28);
  transform: translate(-50%, -50%);
}

.play-button::before {
  width: 0;
  height: 0;
  margin-left: 5px;
  border-top: 10px solid transparent;
  border-bottom: 10px solid transparent;
  border-left: 16px solid var(--orange);
  content: "";
}

.hero-videos iframe {
  width: 100%;
  height: 100%;
  min-height: 260px;
  border: 0;
  border-radius: 7px;
  background: #dce7eb;
}

.system-video {
  display: block;
  width: 100%;
  height: 100%;
  min-height: 0;
  overflow: hidden;
  border: 0;
  border-radius: 7px;
  background: #dce7eb;
  box-shadow: 0 14px 34px rgba(0, 86, 94, 0.1);
}

.media-note {
  position: absolute;
  right: 18px;
  bottom: 18px;
  max-width: 250px;
  padding: 16px;
  color: var(--ink);
  background: rgba(255, 255, 255, 0.9);
  border: 1px solid rgba(255, 255, 255, 0.9);
  border-radius: var(--radius);
  backdrop-filter: blur(12px);
}

.media-note strong,
.media-note span {
  display: block;
}

.media-note span {
  color: var(--muted);
  font-size: 13px;
}

.intro {
  display: grid;
  grid-template-columns: 0.8fr 1.2fr;
  gap: 42px;
  padding: 54px 0 74px;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

h2 {
  margin: 0;
  font-size: clamp(26px, 3vw, 40px);
  line-height: 1.05;
  letter-spacing: 0;
}

.intro p,
.section-head p,
.quote-copy p,
.contact-panel p {
  margin: 0;
  color: var(--muted);
  font-size: 16px;
}

.systems,
.benefits,
.applications,
.process,
.quote-contact {
  padding: 78px 0;
}

.systems.section {
  width: 100%;
  max-width: none;
  padding: 72px 0 0;
  scroll-margin-top: 96px;
}

.systems > .section-head {
  width: min(calc(100% - 40px), var(--max));
  max-width: var(--max);
  margin-left: auto;
  margin-right: auto;
}

.section-head {
  display: grid;
  grid-template-columns: minmax(0, 0.8fr) minmax(300px, 0.62fr);
  gap: 42px;
  align-items: end;
  margin-bottom: 34px;
}

.applications .section-head,
.process .section-head {
  display: block;
  max-width: 680px;
  margin-left: auto;
  margin-right: auto;
  text-align: center;
}

.applications .section-head::before,
.process .section-head::before {
  display: block;
  margin-bottom: 8px;
  color: var(--accent);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.applications .section-head::before {
  content: "Применение";
}

.process .section-head::before {
  content: "Этапы работы";
}

.applications .section-head p,
.process .section-head p {
  margin-top: 12px;
}

.system-panel {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(420px, 0.92fr);
  gap: clamp(34px, 5vw, 76px);
  align-items: stretch;
  width: 100%;
  max-width: none;
  min-height: 100vh;
  margin: 0;
  padding: 56px max(40px, calc((100vw - var(--max)) / 2)) 76px;
  overflow: hidden;
  background: #ffffff;
  border: 0;
  border-radius: 0;
  box-shadow: none;
}

.system-panel::before {
  position: absolute;
  top: 48px;
  right: max(40px, calc((100vw - var(--max)) / 2));
  color: var(--orange);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

#folding::before {
  content: "Система 01";
}

#sliding::before {
  content: "Система 02";
  right: auto;
  left: max(40px, calc((100vw - var(--max)) / 2));
}

.system-panel.is-active {
  display: grid;
}

.system-panel-reverse .system-media {
  order: 2;
}

.system-panel-reverse {
  background: #f4f7f6;
}

.system-panel-reverse .system-content {
  order: 1;
}

.system-media {
  display: grid;
  grid-template-rows: minmax(0, 1fr) minmax(0, 1fr);
  gap: 16px;
  overflow: hidden;
  align-self: stretch;
  border-radius: 0;
  background: transparent;
  box-shadow: none;
}

.system-media > img {
  width: 100%;
  height: 100%;
  min-height: 0;
  object-fit: cover;
  border-radius: 7px;
  box-shadow: 0 22px 70px rgba(0, 86, 94, 0.12);
}

.system-content {
  display: flex;
  min-height: 100%;
  flex-direction: column;
  justify-content: center;
  padding: 22px 4px;
  max-width: 590px;
}

.system-content h3,
.benefit-grid h3 {
  margin: 0;
  font-size: 30px;
  line-height: 1.1;
}

.system-content p {
  margin: 16px 0 0;
  color: var(--muted);
}

.spec-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin-top: 24px;
}

.spec-grid div {
  padding: 14px;
  background: white;
  border: 1px solid var(--line);
  border-radius: 7px;
}

.spec-grid span,
.contact-grid span {
  display: block;
  color: var(--muted);
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
}

.spec-grid strong {
  display: block;
  margin-top: 4px;
  font-size: 16px;
}

.check-list {
  display: grid;
  gap: 10px;
  margin: 24px 0 0;
  padding: 0;
  list-style: none;
}

.check-list li {
  position: relative;
  padding-left: 28px;
  color: #3d4e58;
}

.check-list li::before {
  position: absolute;
  left: 0;
  top: 2px;
  color: var(--accent);
  content: "✓";
  font-weight: 800;
}

.benefits.section {
  width: 100%;
  max-width: none;
  min-height: auto;
  display: grid;
  align-content: center;
  background: #00565e;
}

.benefits.section {
  padding-top: 62px;
  padding-bottom: 62px;
}

.benefits .section-head,
.benefit-grid {
  width: min(calc(100% - 40px), var(--max));
  max-width: var(--max);
  margin-left: auto;
  margin-right: auto;
}

.benefits h2,
.benefit-grid h3 {
  color: white;
}

.benefits .section-head p,
.benefit-grid p {
  color: #aebcc4;
}

.benefit-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1px;
  background: rgba(255, 255, 255, 0.15);
  border: 1px solid rgba(255, 255, 255, 0.15);
}

.benefit-grid article {
  min-height: 260px;
  padding: 28px;
  background: #00565e;
}

.icon {
  display: inline-flex;
  margin-bottom: 70px;
  color: #ffb067;
  font-weight: 800;
}

.application-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
  counter-reset: application;
}

.application-grid article {
  position: relative;
  display: grid;
  overflow: hidden;
  min-height: 168px;
  align-content: center;
  background:
    linear-gradient(135deg, rgba(0, 86, 94, 0.06), transparent 48%),
    white;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 0 16px 34px rgba(16, 49, 61, 0.06);
  counter-increment: application;
}

.application-grid article::before {
  position: absolute;
  top: 18px;
  right: 20px;
  color: rgba(0, 86, 94, 0.16);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0.12em;
  content: counter(application, decimal-leading-zero);
}

.application-grid article::after {
  position: absolute;
  right: 0;
  bottom: 0;
  width: 64px;
  height: 4px;
  background: var(--orange);
  content: "";
}

.application-grid div {
  display: grid;
  gap: 18px;
  align-items: start;
  min-height: 132px;
  padding: 30px 28px 26px;
}

.application-grid div img {
  width: 42px;
  height: 42px;
  object-fit: contain;
  opacity: 0.78;
}

.application-grid span {
  max-width: 210px;
  font-size: 18px;
  font-weight: 700;
  line-height: 1.14;
}

.process {
  border-top: 1px solid var(--line);
}

.process-list {
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  gap: 18px;
  margin: 0;
  padding: 0;
  list-style: none;
  border: 0;
}

.process-list li {
  position: relative;
  min-height: 188px;
  padding: 0 8px;
  text-align: center;
}

.process-list li:not(:last-child)::after {
  position: absolute;
  top: 30px;
  right: -18px;
  width: 36px;
  height: 1px;
  background: linear-gradient(90deg, var(--accent) 0 35%, transparent 35% 100%);
  background-size: 8px 1px;
  content: "";
}

.process-list span {
  display: grid;
  width: 60px;
  height: 60px;
  place-items: center;
  margin: 0 auto;
  color: var(--orange);
  background: white;
  border: 1px solid var(--orange);
  border-radius: 50%;
  font-weight: 800;
  box-shadow: 0 10px 26px rgba(238, 114, 1, 0.16);
}

.process-list strong {
  display: block;
  margin-top: 18px;
  font-size: 16px;
  line-height: 1.15;
}

.process-list p {
  margin: 12px 0 0;
  color: var(--muted);
  font-size: 14px;
}

.process.section {
  width: 100%;
  max-width: none;
  padding: 86px 0;
  background: #f4f7f6;
}

.process .section-head,
.process-list {
  width: min(calc(100% - 40px), var(--max));
  max-width: var(--max);
  margin-left: auto;
  margin-right: auto;
}

.quote-contact {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 28px;
  align-items: start;
}

.quote-form {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  min-height: 380px;
  padding: 32px;
  background: var(--soft);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 0 18px 50px rgba(16, 49, 61, 0.07);
}

.quote-form h2 {
  grid-column: 1 / -1;
  font-size: 28px;
}

.quote-form label {
  display: grid;
  gap: 8px;
}

.quote-form span {
  color: #40505a;
  font-size: 13px;
  font-weight: 700;
}

.quote-form input,
.quote-form select,
.quote-form textarea {
  width: 100%;
  min-height: 48px;
  padding: 12px 13px;
  color: var(--ink);
  background: white;
  border: 1px solid var(--line);
  border-radius: 7px;
  font: inherit;
  font-size: 15px;
}

.quote-form textarea {
  resize: vertical;
}

.file-field input[type="file"] {
  min-height: auto;
  padding: 12px 13px;
  cursor: pointer;
}

.quote-form button:disabled {
  opacity: 0.65;
  cursor: wait;
  transform: none;
}

.full {
  grid-column: 1 / -1;
}

.form-status {
  grid-column: 1 / -1;
  margin: 0;
  color: var(--accent-dark);
  font-weight: 700;
}

.contact-card {
  display: grid;
  grid-template-columns: 0.88fr 1.12fr;
  min-height: 380px;
  overflow: hidden;
  background: white;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 0 18px 50px rgba(16, 49, 61, 0.07);
}

.contact-info {
  display: grid;
  align-content: start;
  gap: 18px;
  padding: 32px;
}

.contact-info h2 {
  font-size: 28px;
}

.contact-info a,
.contact-info div {
  display: grid;
  gap: 4px;
}

.contact-info span {
  color: var(--orange);
  font-size: 12px;
  font-weight: 800;
  text-transform: uppercase;
}

.contact-info strong {
  display: block;
  font-size: 15px;
  line-height: 1.25;
}

.contact-card > img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.contact-photo {
  filter: brightness(1.08) contrast(1.08) saturate(1.05);
  object-position: 52% center;
}

.site-footer {
  display: flex;
  justify-content: space-between;
  width: calc(100% - 40px);
  max-width: var(--max);
  margin: 0 auto;
  padding: 26px 0 36px;
  color: var(--muted);
  font-size: 14px;
}

.back-top {
  position: fixed;
  right: 22px;
  bottom: 22px;
  z-index: 30;
  display: grid;
  width: 46px;
  height: 46px;
  place-items: center;
  color: white;
  background: var(--accent);
  border-radius: 50%;
  box-shadow: 0 14px 34px rgba(0, 86, 94, 0.22);
  font-size: 20px;
  font-weight: 800;
}

.back-top:hover {
  background: var(--orange);
}

@media (max-width: 980px) {
  .site-header {
    grid-template-columns: auto auto;
    width: calc(100% - 28px);
    margin-top: 14px;
    padding: 14px 16px;
    border: 1px solid rgba(217, 226, 231, 0.9);
    border-radius: var(--radius);
  }

  .menu-toggle {
    display: grid;
    gap: 6px;
    justify-self: end;
    width: 42px;
    height: 42px;
    place-content: center;
    background: white;
    border: 1px solid var(--line);
    border-radius: 7px;
  }

  .menu-toggle span {
    width: 18px;
    height: 2px;
    background: var(--ink);
  }

  .site-nav,
  .header-cta {
    display: none;
  }

  .site-header.is-open .site-nav {
    display: grid;
    grid-column: 1 / -1;
    justify-content: stretch;
    gap: 0;
  }

  .site-header.is-open .site-nav a {
    padding: 14px 0;
    border-top: 1px solid var(--line);
  }

  .hero,
  .intro,
  .section-head,
  .system-panel,
  .quote {
    grid-template-columns: 1fr;
  }

  .systems.section {
    padding-top: 64px;
  }

  .systems > .section-head,
  .system-panel {
    width: 100%;
  }

  .system-panel {
    min-height: auto;
    gap: 24px;
    padding: 58px 14px;
  }

  .system-panel::before {
    top: 28px;
    right: 14px;
  }

  #sliding::before {
    right: auto;
    left: 14px;
  }

  .system-content {
    padding: 8px 2px 14px;
  }

  .system-video {
    max-width: 100%;
  }

  .system-panel-reverse .system-media,
  .system-panel-reverse .system-content {
    order: initial;
  }

  .hero {
    min-height: auto;
    padding-bottom: 74px;
  }

  .hero-media,
  .hero-media img {
    min-height: 340px;
    height: 340px;
  }

  .hero-videos {
    grid-template-columns: 1fr;
    height: auto;
    min-height: 0;
  }

  .hero-videos iframe,
  .video-card {
    aspect-ratio: 16 / 9;
    min-height: 0;
  }

  .video-card img {
    min-height: 0;
  }

  .benefit-grid,
  .application-grid,
  .quote-contact {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .process-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (max-width: 640px) {
  body {
    width: 100%;
  }

  .site-header,
  .section,
  .benefits .section-head,
  .benefit-grid,
  .site-footer {
    width: calc(100% - 28px);
    max-width: var(--max);
  }

  .brand-word {
    font-size: 18px;
  }

  .brand-logo {
    font-size: 21px;
  }

  .hero {
    padding-top: 44px;
    gap: 32px;
  }

  .scroll-cue {
    bottom: 18px;
    font-size: 12px;
  }

  .hero-copy h1 {
    max-width: 100%;
    font-size: 28px;
    line-height: 1.04;
    overflow-wrap: anywhere;
  }

  .hero-copy p {
    max-width: 100%;
    font-size: 16px;
    overflow-wrap: anywhere;
  }

  .hero-note {
    grid-template-columns: 1fr;
    gap: 10px;
  }

  .hero-note h2 {
    font-size: 22px;
  }

  .hero-actions {
    display: grid;
    grid-template-columns: 1fr;
  }

  .hero-actions .button {
    width: 100%;
  }

  .hero-facts,
  .hero-note,
  .spec-grid,
  .quote-form,
  .benefit-grid,
  .application-grid,
  .process-list,
  .quote-contact,
  .contact-card {
    grid-template-columns: 1fr;
  }

  .hero-media,
  .hero-media img,
  .system-media img {
    min-height: 280px;
    height: 280px;
  }

  .hero-videos {
    height: auto;
    min-height: 0;
  }

  .intro,
  .systems,
  .benefits,
  .applications,
  .process,
  .quote,
  .contacts {
    padding-top: 58px;
    padding-bottom: 58px;
  }

  .systems.section {
    padding-top: 58px;
    padding-bottom: 0;
  }

  .system-panel {
    margin-top: 22px;
    padding: 58px 14px 44px;
  }

  .system-content h3 {
    font-size: 24px;
  }

  .system-media {
    grid-template-rows: 280px 220px;
  }

  .process.section {
    padding: 58px 0;
  }

  .process .section-head,
  .process-list {
    width: calc(100% - 28px);
  }

  .back-top {
    right: 14px;
    bottom: 14px;
    width: 40px;
    height: 40px;
    font-size: 18px;
  }

  .quote-form,
  .contact-info {
    padding: 24px;
  }

  .contact-card > img {
    height: 240px;
  }

  .process-list li {
    min-height: 190px;
  }

  .process-list li::after {
    display: none;
  }

  .site-footer {
    display: grid;
    gap: 10px;
  }
}