/* Renlong Pipe Fittings — site stylesheet
   Design language: mill test certificate / fabrication drawing.
   Single accent (oxide red) reserved for dimension callouts and primary actions. */

:root {
  --paper: #f4f5f3;
  --surface: #ffffff;
  --ink: #171a1c;
  --steel: #5c666c;
  --line: #d2d7d4;
  --oxide: #a33a1f;
  --oxide-deep: #7c2a14;
  --band: #1d2226;
  --band-ink: #c9d1cd;
  --display: "Barlow Condensed", "Arial Narrow", "Microsoft YaHei", sans-serif;
  --body: "Barlow", "Segoe UI", "Microsoft YaHei", "PingFang SC", sans-serif;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--body);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

a { color: inherit; }

h1, h2, h3 {
  font-family: var(--display);
  font-weight: 600;
  letter-spacing: 0.01em;
  line-height: 1.12;
  margin: 0;
  text-wrap: balance;
}

h1 { font-size: clamp(2.1rem, 4.6vw, 3.5rem); }
h2 { font-size: clamp(1.5rem, 2.6vw, 2.1rem); }
h3 { font-size: 1.18rem; }
p { margin: 0 0 1em; }
p:last-child { margin-bottom: 0; }

.wrap { max-width: 1180px; margin: 0 auto; padding: 0 22px; }

a:focus-visible,
button:focus-visible,
input:focus-visible,
textarea:focus-visible {
  outline: 2px solid var(--oxide);
  outline-offset: 2px;
}

/* ---------- dimension-line motif (drawn from drawing callouts) ---------- */

.dim {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--steel);
  font-family: var(--body);
  font-size: 0.82rem;
  font-weight: 500;
  letter-spacing: 0.02em;
}

.dim::before,
.dim::after {
  content: "";
  height: 1px;
  background: var(--line);
}

.dim::before { width: 24px; flex: 0 0 24px; }
.dim::after { flex: 1 1 auto; }

.dim.on-dark { color: #8f9b96; }
.dim.on-dark::before, .dim.on-dark::after { background: #3a423f; }

/* ---------- top utility bar ---------- */

.topbar {
  background: var(--band);
  color: var(--band-ink);
  font-size: 0.8rem;
}

.topbar .wrap {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 20px;
  align-items: center;
  min-height: 38px;
}

.topbar a { text-decoration: none; }
.topbar a:hover { color: #fff; text-decoration: underline; }
.topbar .spacer { margin-left: auto; }

/* ---------- header ---------- */

.masthead {
  background: var(--surface);
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
  z-index: 20;
}

.masthead .wrap {
  display: flex;
  align-items: center;
  gap: 18px;
  min-height: 72px;
}

.wordmark {
  font-family: var(--display);
  font-size: 1.5rem;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  text-decoration: none;
  white-space: nowrap;
}

.wordmark small {
  display: block;
  font-family: var(--body);
  font-size: 0.66rem;
  font-weight: 400;
  letter-spacing: 0.08em;
  color: var(--steel);
  text-transform: none;
}

nav.main { margin-left: auto; }

nav.main ul {
  display: flex;
  gap: 26px;
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: 0.94rem;
  font-weight: 500;
}

nav.main a {
  text-decoration: none;
  padding: 6px 0;
  border-bottom: 2px solid transparent;
}

nav.main a:hover { border-bottom-color: var(--line); }
nav.main a[aria-current="page"] { border-bottom-color: var(--oxide); }

.btn {
  display: inline-block;
  font-family: var(--body);
  font-size: 0.92rem;
  font-weight: 600;
  text-decoration: none;
  text-align: center;
  padding: 11px 20px;
  border: 1px solid var(--oxide);
  border-radius: 2px;
  background: var(--oxide);
  color: #fff;
  cursor: pointer;
}

.btn:hover { background: var(--oxide-deep); border-color: var(--oxide-deep); }

.btn.ghost {
  background: transparent;
  color: var(--ink);
  border-color: var(--line);
}

.btn.ghost:hover { border-color: var(--ink); background: transparent; }

.btn.on-dark {
  background: transparent;
  color: #fff;
  border-color: #4a534f;
}

.btn.on-dark:hover { border-color: #fff; background: transparent; }

.navtoggle {
  display: none;
  margin-left: auto;
  background: none;
  border: 1px solid var(--line);
  border-radius: 2px;
  padding: 8px 11px;
  font: inherit;
  cursor: pointer;
}

/* ---------- hero ---------- */

.hero {
  position: relative;
  background: #23282b;
  color: #fff;
  overflow: hidden;
}

.hero img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 55%;
  opacity: 0.5;
}

.hero .wrap {
  position: relative;
  padding-top: 74px;
  padding-bottom: 74px;
  max-width: 1180px;
}

.hero h1 { max-width: 17ch; }

.hero .lede {
  margin-top: 20px;
  max-width: 56ch;
  font-size: 1.02rem;
  color: #dfe4e1;
}

.hero .actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

.specstrip {
  margin-top: 34px;
  border-top: 1px solid #454d4a;
  padding-top: 14px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(190px, 1fr));
  gap: 12px 26px;
  font-size: 0.86rem;
  color: #cdd4d0;
}

.specstrip div span {
  display: block;
  font-size: 0.7rem;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  color: #8f9b96;
  margin-bottom: 2px;
}

/* ---------- sections ---------- */

section { padding: 62px 0; }
section.tight { padding: 44px 0; }

.sechead { margin-bottom: 30px; }
.sechead p { margin-top: 12px; max-width: 68ch; color: var(--steel); }

.band { background: var(--band); color: var(--band-ink); }
.band h2, .band h3 { color: #fff; }
.band p { color: var(--band-ink); }

/* ---------- product index table ---------- */

.index-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--surface);
  border: 1px solid var(--line);
  font-size: 0.92rem;
}

.index-table caption {
  caption-side: top;
  text-align: left;
  font-size: 0.8rem;
  color: var(--steel);
  padding-bottom: 10px;
}

.index-table th,
.index-table td {
  border-bottom: 1px solid var(--line);
  padding: 14px 16px;
  text-align: left;
  vertical-align: top;
}

.index-table thead th {
  background: #eceeec;
  font-size: 0.74rem;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  color: var(--steel);
  font-weight: 600;
  white-space: nowrap;
}

.index-table tbody tr:last-child td { border-bottom: none; }

.index-table .fam {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  min-width: 250px;
}

.index-table .fam img {
  width: 60px;
  height: 60px;
  object-fit: cover;
  flex: 0 0 60px;
  background: #e8ebe9;
}

.index-table .fam strong { display: block; font-weight: 600; }
.index-table .fam a { text-decoration: none; }
.index-table .fam a:hover { color: var(--oxide); text-decoration: underline; }
.index-table .fam em {
  font-style: normal;
  font-size: 0.82rem;
  color: var(--steel);
}

.nums { font-variant-numeric: tabular-nums; }

/* ---------- fact grid ---------- */

.facts {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.facts > div {
  background: var(--surface);
  padding: 22px;
}

.facts h3 { margin-bottom: 8px; }
.facts p { font-size: 0.92rem; color: var(--steel); }

.band .facts { background: #2c3336; border-color: #2c3336; }
.band .facts > div { background: var(--band); }
.band .facts p { color: #a7b0ac; }

/* ---------- photo strip ---------- */

.shots {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 18px;
}

.shots figure { margin: 0; }

.shots img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  background: #e8ebe9;
}

.shots figcaption {
  font-size: 0.84rem;
  color: var(--steel);
  padding-top: 9px;
  border-top: 1px solid var(--line);
  margin-top: 9px;
}

.band .shots figcaption { color: #a7b0ac; border-top-color: #2c3336; }

/* ---------- document cards (certificates) ---------- */

.docs {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 18px;
}

.docs figure { margin: 0; }

.docs a {
  display: block;
  padding: 8px;
  background: #fff;
  border: 1px solid var(--line);
}

.docs a:hover { border-color: var(--oxide); }

.docs img { display: block; width: 100%; height: auto; }

.docs figcaption {
  font-size: 0.84rem;
  color: var(--steel);
  padding-top: 9px;
  border-top: 1px solid var(--line);
  margin-top: 9px;
}

.docs figcaption b { display: block; color: var(--ink); font-weight: 600; margin-bottom: 4px; }

/* ---------- detail rows (products page) ---------- */

.family {
  display: grid;
  grid-template-columns: minmax(240px, 320px) 1fr;
  gap: 30px;
  padding: 34px 0;
  border-bottom: 1px solid var(--line);
}

.family:last-of-type { border-bottom: none; }
.family img { width: 100%; aspect-ratio: 4 / 3; object-fit: cover; background: #e8ebe9; }

.spec-list {
  list-style: none;
  margin: 16px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 0 26px;
  font-size: 0.92rem;
}

.spec-list li {
  display: flex;
  gap: 10px;
  padding: 8px 0;
  border-top: 1px solid var(--line);
}

.spec-list b {
  flex: 0 0 96px;
  font-weight: 600;
  color: var(--steel);
  font-size: 0.78rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  padding-top: 2px;
}

/* ---------- plain data table ---------- */

.data {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
  background: var(--surface);
  border: 1px solid var(--line);
}

.data th, .data td {
  border-bottom: 1px solid var(--line);
  padding: 11px 14px;
  text-align: left;
  vertical-align: top;
}

.data th {
  background: #eceeec;
  font-size: 0.74rem;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  color: var(--steel);
}

.data tbody tr:last-child td { border-bottom: none; }
.data td:first-child { font-weight: 600; white-space: nowrap; }

/* ---------- contact ---------- */

.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 30px;
}

.kv { list-style: none; margin: 0; padding: 0; }

.kv li {
  padding: 12px 0;
  border-top: 1px solid var(--line);
  display: flex;
  gap: 14px;
  font-size: 0.95rem;
}

.kv b {
  flex: 0 0 112px;
  font-size: 0.76rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--steel);
  font-weight: 600;
  padding-top: 3px;
}

.band .kv li { border-top-color: #2c3336; }
.band .kv b { color: #8f9b96; }

ol.steps {
  counter-reset: step;
  list-style: none;
  margin: 0;
  padding: 0;
}

ol.steps li {
  counter-increment: step;
  position: relative;
  padding: 14px 0 14px 46px;
  border-top: 1px solid var(--line);
  font-size: 0.94rem;
}

ol.steps li::before {
  content: counter(step);
  position: absolute;
  left: 0;
  top: 15px;
  width: 26px;
  height: 26px;
  border: 1px solid var(--oxide);
  color: var(--oxide);
  font-size: 0.8rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* ---------- footer ---------- */

footer {
  background: var(--band);
  color: #97a19d;
  font-size: 0.86rem;
  padding: 40px 0;
}

footer a { color: #cdd4d0; text-decoration: none; }
footer a:hover { text-decoration: underline; }

.foot-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 26px;
}

.foot-grid h3 {
  color: #fff;
  font-size: 0.82rem;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  margin-bottom: 12px;
  font-family: var(--body);
  font-weight: 600;
}

.foot-grid ul { list-style: none; margin: 0; padding: 0; }
.foot-grid li { padding: 4px 0; }

.footnote {
  margin-top: 30px;
  padding-top: 18px;
  border-top: 1px solid #2c3336;
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
  font-size: 0.8rem;
}

.footnote .spacer { margin-left: auto; }

/* ---------- responsive ---------- */

@media (max-width: 900px) {
  .navtoggle { display: block; }

  nav.main {
    order: 3;
    flex-basis: 100%;
    margin-left: 0;
    display: none;
  }

  nav.main.open { display: block; }

  nav.main ul {
    flex-direction: column;
    gap: 0;
    padding: 8px 0 16px;
  }

  nav.main li { border-top: 1px solid var(--line); }
  nav.main a { display: block; padding: 12px 0; }

  .masthead .wrap { flex-wrap: wrap; padding-top: 10px; padding-bottom: 10px; }

  .family { grid-template-columns: 1fr; gap: 18px; }
  .hero .wrap { padding-top: 52px; padding-bottom: 52px; }
  section { padding: 46px 0; }
}

@media (max-width: 640px) {
  body { font-size: 15px; }
  .topbar { font-size: 0.76rem; }
  .topbar .spacer { margin-left: 0; }

  /* The product index becomes a stacked record on narrow screens so nothing
     has to be scrolled sideways or dropped. Labels come from data-label. */
  .index-table,
  .index-table thead,
  .index-table tbody,
  .index-table tr,
  .index-table th,
  .index-table td { display: block; width: auto; }

  .index-table { border-left: none; border-right: none; }
  .index-table thead { display: none; }
  .index-table caption { padding: 0 0 6px; }

  .index-table tr {
    border-bottom: 1px solid var(--line);
    padding: 16px 0 14px;
  }

  .index-table tbody tr:last-child { border-bottom: none; }

  .index-table td {
    border-bottom: none;
    padding: 5px 16px;
    font-size: 0.88rem;
  }

  .index-table td:first-child { padding: 0 16px 10px; }
  .index-table .fam { min-width: 0; }

  .index-table td[data-label]::before {
    content: attr(data-label) "  ";
    display: inline;
    color: var(--steel);
    font-size: 0.72rem;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    font-weight: 600;
    margin-right: 4px;
  }

  .kv b, .spec-list b { flex-basis: 88px; }
  .hero h1 { max-width: none; }
}

/* Product index — the family menu at the top of the products page */
.famindex {
  background: var(--surface);
  border: 1px solid var(--line);
  margin-bottom: 38px;
}

.famindex-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 12px;
  padding: 13px 18px;
  border-bottom: 1px solid var(--line);
  font-family: var(--display);
  font-size: 0.78rem;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: var(--steel);
}

.famindex ol {
  list-style: none;
  margin: 0;
  padding: 0;
  counter-reset: fam;
}

.famindex li { border-bottom: 1px solid var(--line); }
.famindex li:last-child { border-bottom: none; }

.famindex a {
  display: grid;
  grid-template-columns: 96px 1fr auto;
  gap: 18px;
  align-items: center;
  padding: 14px 18px;
  text-decoration: none;
}

.famindex a:hover { background: #fafbfa; }
.famindex a:hover .fi-name { color: var(--oxide); }

.famindex img {
  width: 96px;
  height: 68px;
  object-fit: cover;
  background: #e8ebe9;
}

.famindex .fi-name {
  display: block;
  font-family: var(--display);
  font-size: 1.15rem;
  font-weight: 600;
  line-height: 1.25;
}

.famindex .fi-desc {
  display: block;
  font-size: 0.85rem;
  color: var(--steel);
  line-height: 1.45;
}

.famindex .fi-meta {
  font-family: var(--display);
  font-size: 0.84rem;
  letter-spacing: 0.04em;
  color: var(--oxide);
  white-space: nowrap;
}

@media (max-width: 640px) {
  .famindex a {
    grid-template-columns: 68px 1fr;
    gap: 14px;
    padding: 12px 14px;
  }
  .famindex img { width: 68px; height: 56px; }
  .famindex .fi-name { font-size: 1.02rem; }
  .famindex .fi-meta { grid-column: 1 / -1; color: var(--steel); }
}

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