:root {
  --ink: #16191d;
  --text: #30363d;
  --muted: #65717d;
  --line: #dde4ea;
  --paper: #f4f1e8;
  --mist: #eef3f5;
  --white: #ffffff;
  --night: #11171b;
  --steel: #43515d;
  --accent: #c8462e;
  --accent-dark: #94331f;
  --teal: #0f726d;
  --blue: #315f8d;
  --gold: #b9842d;
  --shadow: 0 16px 40px rgba(30, 42, 52, 0.13);
  --radius: 8px;
  --header-height: 78px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--text);
  background: var(--white);
  font-family: Arial, Helvetica, sans-serif;
  line-height: 1.6;
}

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

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

button,
input {
  font: inherit;
}

button {
  cursor: pointer;
}

.section-inner {
  width: min(1180px, calc(100% - 40px));
  margin: 0 auto;
}

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 50;
  height: var(--header-height);
  color: var(--ink);
  background: rgba(255, 255, 255, 0.94);
  border-bottom: 1px solid rgba(221, 228, 234, 0.86);
  backdrop-filter: blur(14px);
}

.header-inner {
  width: min(1180px, calc(100% - 40px));
  height: 100%;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
}

.brand-mark {
  width: 52px;
  height: 52px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex: 0 0 auto;
  color: var(--white);
  background: linear-gradient(135deg, var(--accent), var(--blue));
  border-radius: 8px;
  font-size: 18px;
  font-weight: 900;
}

.brand strong,
.brand small {
  display: block;
  line-height: 1.2;
}

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

.brand small {
  margin-top: 2px;
  color: var(--muted);
  font-size: 12px;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav-list a {
  min-height: 40px;
  display: inline-flex;
  align-items: center;
  padding: 0 13px;
  border-radius: 6px;
  color: var(--steel);
  font-size: 14px;
  font-weight: 800;
}

.nav-list a:hover,
.nav-list a:focus-visible {
  color: var(--accent-dark);
  background: #faeae4;
  outline: none;
}

.nav-list .nav-contact {
  color: var(--white);
  background: var(--accent);
}

.nav-list .nav-contact:hover,
.nav-list .nav-contact:focus-visible {
  color: var(--white);
  background: var(--accent-dark);
}

.menu-button {
  width: 44px;
  height: 44px;
  display: none;
  place-items: center;
  padding: 0;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--white);
}

.menu-button span {
  width: 20px;
  height: 2px;
  display: block;
  margin: 3px 0;
  background: var(--ink);
  border-radius: 2px;
}

.hero {
  position: relative;
  min-height: 84svh;
  display: grid;
  align-items: end;
  overflow: hidden;
  color: var(--white);
  background: var(--night);
  padding: 116px 0 58px;
}

.hero-media,
.hero-overlay {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

.hero-media {
  object-fit: cover;
  object-position: center;
  filter: saturate(1.02) contrast(1.05);
}

.hero-overlay {
  background:
    linear-gradient(90deg, rgba(12, 16, 19, 0.9), rgba(12, 16, 19, 0.62) 48%, rgba(12, 16, 19, 0.2)),
    linear-gradient(0deg, rgba(12, 16, 19, 0.88), rgba(12, 16, 19, 0) 46%);
}

.hero-inner {
  position: relative;
  z-index: 1;
}

.eyebrow,
.section-kicker,
.type-label,
.toc-title {
  margin: 0;
  color: var(--accent);
  font-size: 13px;
  font-weight: 900;
  letter-spacing: 0;
  text-transform: uppercase;
}

.hero .eyebrow {
  color: #ffbd68;
}

.hero h1 {
  max-width: 880px;
  margin: 10px 0 16px;
  color: var(--white);
  font-size: 64px;
  line-height: 1;
  letter-spacing: 0;
}

.hero-copy {
  max-width: 760px;
  margin: 0;
  color: rgba(255, 255, 255, 0.88);
  font-size: 20px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.button {
  min-height: 46px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 0 18px;
  border: 1px solid transparent;
  border-radius: 6px;
  font-weight: 900;
  white-space: nowrap;
  transition: transform 0.18s ease, background 0.18s ease, border-color 0.18s ease;
}

.button:hover,
.button:focus-visible {
  transform: translateY(-1px);
  outline: none;
}

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

.button-primary:hover,
.button-primary:focus-visible {
  background: var(--accent-dark);
}

.button-quiet {
  color: var(--white);
  border-color: rgba(255, 255, 255, 0.48);
  background: rgba(255, 255, 255, 0.12);
}

.button-quiet:hover,
.button-quiet:focus-visible {
  background: rgba(255, 255, 255, 0.22);
}

.hero-metrics {
  width: min(900px, 100%);
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  margin-top: 36px;
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.22);
}

.hero-metrics div {
  min-height: 108px;
  padding: 18px;
  background: rgba(10, 14, 16, 0.56);
}

.hero-metrics strong {
  display: block;
  color: var(--white);
  font-size: 20px;
  line-height: 1.2;
}

.hero-metrics span {
  display: block;
  margin-top: 8px;
  color: rgba(255, 255, 255, 0.76);
  font-size: 14px;
}

.intro-band {
  background: var(--paper);
  border-bottom: 1px solid #e3d8c4;
  padding: 36px 0;
  scroll-margin-top: var(--header-height);
}

.intro-grid {
  display: grid;
  grid-template-columns: 0.85fr 1.15fr;
  gap: 48px;
  align-items: center;
}

.intro-grid h2,
.section-head h2,
.feature-copy h2 {
  margin: 8px 0 0;
  color: var(--ink);
  font-size: 40px;
  line-height: 1.18;
  letter-spacing: 0;
}

.intro-grid p {
  margin: 0;
  color: var(--steel);
  font-size: 17px;
}

.section {
  padding: 84px 0;
  scroll-margin-top: var(--header-height);
}

.section-muted {
  background: var(--mist);
}

.section-head {
  max-width: 780px;
  margin-bottom: 34px;
}

.section-head.compact {
  margin-bottom: 28px;
}

.section-head p,
.feature-copy > p {
  margin: 14px 0 0;
  color: var(--muted);
  font-size: 17px;
}

.article-layout {
  display: grid;
  grid-template-columns: 260px minmax(0, 1fr);
  gap: 44px;
  align-items: start;
}

.toc {
  position: sticky;
  top: calc(var(--header-height) + 18px);
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
  box-shadow: 0 10px 26px rgba(30, 42, 52, 0.07);
}

.toc-title {
  color: var(--teal);
}

.toc a {
  display: block;
  margin-top: 10px;
  color: var(--steel);
  font-size: 14px;
  font-weight: 800;
}

.toc a:hover,
.toc a:focus-visible {
  color: var(--accent-dark);
  outline: none;
}

.overview-grid,
.safety-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.overview-grid article,
.safety-grid article,
.parts-grid article,
.process-list li,
.type-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
  box-shadow: 0 12px 28px rgba(31, 42, 51, 0.08);
}

.overview-grid article {
  min-height: 170px;
  padding: 24px;
}

.overview-grid span,
.parts-grid span {
  display: block;
  color: var(--teal);
  font-size: 13px;
  font-weight: 900;
  text-transform: uppercase;
}

.overview-grid h3,
.type-content h3,
.safety-grid h3 {
  margin: 8px 0 10px;
  color: var(--ink);
  font-size: 22px;
  line-height: 1.25;
}

.overview-grid p,
.type-content p,
.safety-grid p,
.parts-grid p {
  margin: 0;
  color: var(--muted);
}

.type-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
}

.type-card {
  overflow: hidden;
}

.type-card img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  background: #d8dde1;
}

.type-card:nth-child(2) img {
  object-position: center 32%;
}

.type-content {
  padding: 24px;
}

.type-content h3 {
  font-size: 23px;
}

.clean-list {
  display: grid;
  gap: 8px;
  margin: 18px 0 0;
  padding: 0;
  list-style: none;
}

.clean-list li {
  position: relative;
  padding-left: 18px;
  color: var(--steel);
  font-size: 15px;
}

.clean-list li::before {
  content: "";
  position: absolute;
  top: 0.72em;
  left: 0;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--teal);
}

.feature-grid {
  display: grid;
  grid-template-columns: 0.92fr 1.08fr;
  gap: 42px;
  align-items: center;
}

.principle-steps {
  display: grid;
  gap: 14px;
  margin-top: 26px;
}

.principle-steps div {
  display: grid;
  grid-template-columns: 48px minmax(0, 1fr);
  column-gap: 14px;
  padding: 16px 0;
  border-bottom: 1px solid var(--line);
}

.principle-steps span,
.process-list span {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  color: var(--white);
  background: var(--teal);
  border-radius: 50%;
  font-weight: 900;
  font-size: 13px;
}

.principle-steps strong,
.process-list strong {
  display: block;
  color: var(--ink);
  font-size: 18px;
}

.principle-steps p {
  grid-column: 2;
  margin: 4px 0 0;
  color: var(--muted);
}

.workshop-figure {
  margin: 0;
}

.workshop-figure img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.workshop-figure figcaption {
  margin-top: 12px;
  color: var(--muted);
  font-size: 14px;
}

.filter-label {
  display: block;
  margin-bottom: 8px;
  color: var(--ink);
  font-weight: 900;
}

.glossary-filter {
  width: min(520px, 100%);
  min-height: 46px;
  margin-bottom: 22px;
  padding: 0 14px;
  border: 1px solid var(--line);
  border-radius: 6px;
  color: var(--ink);
  background: var(--white);
}

.glossary-filter:focus {
  border-color: var(--teal);
  outline: 3px solid rgba(15, 114, 109, 0.16);
}

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

.parts-grid article {
  min-height: 158px;
  padding: 22px;
}

.parts-grid article.is-hidden {
  display: none;
}

.parts-grid p {
  margin-top: 8px;
  font-size: 15px;
}

.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
  box-shadow: 0 12px 28px rgba(31, 42, 51, 0.08);
}

table {
  width: 100%;
  min-width: 860px;
  border-collapse: collapse;
}

th,
td {
  padding: 18px 20px;
  border-bottom: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}

th {
  color: var(--ink);
  background: #e7edf0;
  font-size: 15px;
}

td:first-child {
  width: 20%;
  color: var(--ink);
  font-weight: 900;
}

tbody tr:last-child td {
  border-bottom: 0;
}

.selection-layout {
  display: grid;
  gap: 28px;
}

.process-list {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 14px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.process-list li {
  min-height: 228px;
  padding: 22px;
}

.process-list strong {
  margin-top: 18px;
}

.process-list p {
  margin: 8px 0 0;
  color: var(--muted);
  font-size: 15px;
}

.selection-note {
  padding: 22px 24px;
  border-left: 5px solid var(--gold);
  border-radius: 0 var(--radius) var(--radius) 0;
  color: var(--steel);
  background: var(--white);
}

.selection-note strong {
  color: var(--ink);
}

.selection-note p {
  margin: 6px 0 0;
}

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

.safety-grid article {
  min-height: 170px;
  padding: 24px;
}

.faq-layout {
  display: grid;
  grid-template-columns: 0.42fr 1fr;
  gap: 42px;
  align-items: start;
}

.faq-list {
  display: grid;
  gap: 12px;
}

details {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
  box-shadow: 0 10px 24px rgba(31, 42, 51, 0.07);
}

summary {
  min-height: 58px;
  display: flex;
  align-items: center;
  padding: 16px 18px;
  color: var(--ink);
  font-weight: 900;
  cursor: pointer;
}

details p {
  margin: 0;
  padding: 0 18px 18px;
  color: var(--muted);
}

.sticky-contact {
  position: fixed;
  right: 18px;
  bottom: 18px;
  z-index: 60;
  display: flex;
  gap: 8px;
  padding: 8px;
  border: 1px solid rgba(255, 255, 255, 0.4);
  border-radius: var(--radius);
  background: rgba(17, 23, 27, 0.92);
  box-shadow: var(--shadow);
  backdrop-filter: blur(12px);
}

.sticky-contact a {
  min-height: 42px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 13px;
  border-radius: 6px;
  color: var(--white);
  background: var(--accent);
  font-weight: 900;
  white-space: nowrap;
}

.sticky-contact a:nth-child(2) {
  background: var(--teal);
}

.sticky-contact a:nth-child(3) {
  background: var(--blue);
}

.site-footer {
  padding: 24px 0;
  color: rgba(255, 255, 255, 0.74);
  background: #111517;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  gap: 20px;
}

.footer-inner p {
  margin: 0;
}

@media (max-width: 1060px) {
  .nav-list a {
    padding: 0 9px;
  }

  .type-grid,
  .overview-grid,
  .safety-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

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

@media (max-width: 900px) {
  .intro-grid,
  .article-layout,
  .feature-grid,
  .faq-layout {
    grid-template-columns: 1fr;
  }

  .toc {
    position: static;
  }
}

@media (max-width: 760px) {
  :root {
    --header-height: 70px;
  }

  .section-inner,
  .header-inner {
    width: min(100% - 28px, 1180px);
  }

  .menu-button {
    display: grid;
  }

  .nav-list {
    position: absolute;
    top: var(--header-height);
    left: 14px;
    right: 14px;
    display: none;
    flex-direction: column;
    align-items: stretch;
    padding: 10px;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    background: var(--white);
    box-shadow: var(--shadow);
  }

  .nav-list.is-open {
    display: flex;
  }

  .nav-list a {
    justify-content: center;
  }

  .hero {
    min-height: 86svh;
    padding: 98px 0 42px;
  }

  .hero h1 {
    font-size: 42px;
    line-height: 1.08;
  }

  .hero-copy {
    font-size: 17px;
  }

  .hero-metrics {
    grid-template-columns: 1fr;
    margin-top: 26px;
  }

  .hero-metrics div {
    min-height: 80px;
    padding: 14px 16px;
  }

  .intro-grid h2,
  .section-head h2,
  .feature-copy h2 {
    font-size: 31px;
  }

  .section {
    padding: 62px 0;
  }

  .type-grid,
  .overview-grid,
  .safety-grid,
  .parts-grid,
  .process-list {
    grid-template-columns: 1fr;
  }

  .overview-grid article,
  .parts-grid article,
  .process-list li,
  .safety-grid article {
    min-height: auto;
  }

  .sticky-contact {
    left: 10px;
    right: 10px;
    bottom: 10px;
    justify-content: center;
  }

  .sticky-contact a {
    flex: 1;
    padding: 0 8px;
    font-size: 14px;
  }

  .site-footer {
    padding-bottom: 82px;
  }

  .footer-inner {
    flex-direction: column;
  }
}

@media (max-width: 430px) {
  .brand small {
    display: none;
  }

  .brand strong {
    font-size: 16px;
  }

  .brand-mark {
    width: 46px;
    height: 46px;
  }

  .hero h1 {
    font-size: 38px;
  }

  .hero-actions {
    flex-direction: column;
  }

  .button {
    width: 100%;
  }

  summary {
    align-items: flex-start;
  }
}