/* ============================================================
   Jingjiang 310 Metal Technology Co., Ltd. — Light, clean, spacious theme
   ============================================================ */
:root {
  --bg:           #ffffff;
  --bg-soft:      #f8fafc;
  --bg-tint:      #f1f5f9;
  --ink:          #0f172a;
  --ink-soft:     #334155;
  --text:         #475569;
  --text-soft:    #94a3b8;
  --line:         #e2e8f0;
  --line-soft:    #eef2f7;
  --accent:       #1e40af;
  --accent-2:     #2563eb;
  --accent-soft:  #eff6ff;
  --accent-line:  #dbeafe;
  --radius:       8px;
  --radius-lg:    14px;
  --shadow:       0 1px 3px rgba(15,23,42,.05), 0 1px 2px rgba(15,23,42,.04);
  --shadow-md:    0 4px 16px rgba(15,23,42,.06);
  --shadow-lg:    0 12px 32px rgba(15,23,42,.08);
  --container:    1240px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
               "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei",
               "Hiragino Sans GB", sans-serif;
  color: var(--text);
  background: var(--bg);
  font-size: 16px; line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a { color: var(--accent-2); text-decoration: none; transition: color .18s; }
a:hover { color: var(--accent); }
img { max-width: 100%; height: auto; display: block; }

/* ---------- Top info bar ---------- */
.topbar {
  background: var(--bg-soft);
  color: var(--text-soft);
  font-size: 13px;
  border-bottom: 1px solid var(--line);
}
.topbar-in {
  max-width: var(--container);
  margin: 0 auto;
  padding: 10px 24px;
  display: flex; flex-wrap: wrap; gap: 6px 28px;
  align-items: center; justify-content: flex-end;
}
.topbar a { color: var(--accent); }
.topbar a:hover { color: var(--accent-2); }
.topbar .wx { color: var(--ink); font-weight: 500; }

/* ---------- Masthead ---------- */
.masthead {
  background: var(--bg);
  padding: 48px 0 36px;
  border-bottom: 1px solid var(--line);
}
.banner-box {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
  display: flex; flex-direction: column; align-items: center; gap: 32px;
}
.banner-box .banner { display: none; }
.masthead-in {
  max-width: 1080px;
  display: flex; justify-content: center;
}
.brand {
  display: flex; align-items: center; gap: 32px;
}
.brand .logo {
  width: 132px; height: 132px; flex: 0 0 auto; object-fit: contain;
  border-radius: 12px;
  background: var(--bg-soft);
  padding: 8px;
  border: 1px solid var(--line);
}
.brand-text { text-align: left; }
.masthead .cn {
  font-size: clamp(26px, 3.4vw, 38px);
  font-weight: 700; color: var(--ink);
  letter-spacing: 0.3px;
  line-height: 1.25;
}
.masthead .en {
  font-size: 12px; letter-spacing: 3px; color: var(--accent);
  margin-top: 10px; text-transform: uppercase; font-weight: 500;
}
.masthead .tag {
  display: inline-block; margin-top: 20px; padding: 6px 16px;
  background: var(--accent-soft);
  color: var(--accent);
  border: 1px solid var(--accent-line);
  border-radius: 999px;
  font-size: 13px; letter-spacing: 0.3px;
}

/* ---------- Main nav ---------- */
.mainnav {
  background: var(--bg);
  position: sticky; top: 0; z-index: 50;
  border-bottom: 1px solid var(--line);
  box-shadow: 0 1px 0 rgba(15,23,42,.02);
}
.nav-in {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
  display: flex; align-items: center; gap: 0; flex-wrap: wrap;
}
.mainnav a.navlink {
  display: inline-block;
  padding: 18px 22px;
  color: var(--ink-soft);
  font-size: 15px; font-weight: 500;
  border-bottom: 2px solid transparent;
  transition: color .18s, border-color .18s;
}
.mainnav a.navlink:hover {
  color: var(--accent);
  border-bottom-color: var(--accent-line);
}
.mainnav a.navlink.active {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

/* Mobile hamburger */
.nav-toggle { display: none; }
.nav-toggle-btn {
  display: none; list-style: none; cursor: pointer; user-select: none;
  padding: 14px 24px; font-weight: 500; font-size: 15px; color: var(--ink-soft);
  background: var(--bg-soft);
  border-bottom: 1px solid var(--line);
}

/* ---------- Sidebar ---------- */
.sidebar {
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  overflow: hidden;
}
.box + .box {
  margin-top: 18px;
  border-top: 1px solid var(--line);
}
.box-title {
  padding: 16px 22px;
  font-size: 13px; font-weight: 600;
  color: var(--ink);
  letter-spacing: 1.5px;
  text-transform: uppercase;
  background: var(--bg-soft);
  border-bottom: 1px solid var(--line);
}
.cat > summary {
  list-style: none; cursor: pointer; user-select: none;
  padding: 14px 22px; font-weight: 600; font-size: 14.5px;
  color: var(--ink);
  display: flex; justify-content: space-between; align-items: center;
  border-bottom: 1px solid var(--line-soft);
  transition: color .18s, background .18s;
}
.cat:last-child > summary { border-bottom: 0; }
.cat > summary::-webkit-details-marker { display: none; }
.cat > summary::after {
  content: "+"; color: var(--text-soft); font-size: 16px; font-weight: 400;
  transition: transform .2s, color .18s;
}
.cat[open] > summary::after {
  content: "\2212"; color: var(--accent);
}
.cat > summary:hover {
  color: var(--accent);
  background: var(--bg-soft);
}
.cat ul {
  list-style: none;
  padding: 4px 0 8px;
  background: var(--bg-soft);
  border-bottom: 1px solid var(--line-soft);
}
.cat li a {
  display: block;
  padding: 9px 22px 9px 32px;
  font-size: 13.5px; color: var(--text);
  border-left: 2px solid transparent;
  transition: color .15s, background .15s, border-color .15s;
}
.cat li a:hover {
  color: var(--accent);
  background: var(--bg);
  border-left-color: var(--accent-line);
}
.cat li a.active {
  color: var(--accent);
  font-weight: 600;
  border-left-color: var(--accent);
  background: var(--accent-soft);
}

.contact-mini {
  padding: 20px 22px 22px;
  font-size: 14px; color: var(--text);
  border-top: 1px solid var(--line);
  line-height: 1.8;
}
.contact-mini strong {
  color: var(--ink); display: block; margin-bottom: 8px;
  font-size: 14px; font-weight: 600;
}
.contact-mini .tel {
  font-size: 22px; font-weight: 700;
  color: var(--accent);
  letter-spacing: 0.5px;
  margin-bottom: 8px;
}

/* ---------- Container / main ---------- */
.container {
  max-width: var(--container);
  margin: 40px auto 64px;
  padding: 0 24px;
  display: grid;
  grid-template-columns: 290px 1fr;
  gap: 36px;
}
.content { min-width: 0; }

.page-head {
  padding: 32px 0 24px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 32px;
}
.page-head h1 {
  font-size: clamp(24px, 2.8vw, 32px);
  color: var(--ink);
  font-weight: 700;
  letter-spacing: 0.3px;
}
.crumb {
  margin-top: 12px;
  font-size: 13px;
  color: var(--text-soft);
  letter-spacing: 0.3px;
}
.crumb a { color: var(--text-soft); }
.crumb a:hover { color: var(--accent); }

/* ---------- Sections ---------- */
.section { padding: 8px 0 4px; margin-bottom: 40px; }
.section-title {
  font-size: clamp(20px, 2.2vw, 24px);
  color: var(--ink);
  font-weight: 600;
  padding-bottom: 14px; margin-bottom: 24px;
  border-bottom: 1px solid var(--line);
  display: flex; align-items: baseline; gap: 14px;
}
.section-title::before {
  content: ""; display: inline-block;
  width: 4px; height: 20px;
  background: var(--accent);
  border-radius: 2px;
  align-self: center;
}

/* Body typography */
.section p, .section .prose {
  font-size: 15.5px;
  color: var(--text);
  margin: 10px 0;
  text-align: justify;
}
.section strong { color: var(--ink); font-weight: 600; }
.section .hl {
  color: var(--accent);
  font-weight: 600;
}
.section h2, .section h3 {
  color: var(--ink);
  margin: 26px 0 12px;
  font-size: 18px;
  font-weight: 600;
}

/* Product gallery */
.gallery {
  display: grid;
  gap: 18px;
  margin: 24px 0;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
}
.gallery figure {
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: border-color .2s, transform .2s, box-shadow .2s;
  display: flex; flex-direction: column;
}
.gallery figure:hover {
  border-color: var(--accent-line);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}
.gallery figure > a { display: block; }
.gallery img {
  width: 100%;
  aspect-ratio: 4 / 3.3;
  object-fit: cover;
  background: var(--bg-soft);
}
.gallery figcaption {
  padding: 12px 14px;
  font-size: 13.5px;
  color: var(--text);
  text-align: center;
  background: var(--bg);
  border-top: 1px solid var(--line);
  line-height: 1.5;
}

/* Spec / data table */
.table-wrap {
  overflow-x: auto;
  margin: 22px 0;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: var(--bg);
  box-shadow: var(--shadow);
}
table.data {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
  background: var(--bg);
  min-width: 420px;
}
table.data th, table.data td {
  border: 1px solid var(--line);
  padding: 11px 16px;
  text-align: center;
  color: var(--text);
}
table.data th {
  background: var(--bg-tint);
  color: var(--ink);
  font-weight: 600;
  white-space: nowrap;
  letter-spacing: 0.3px;
}
table.data tr:nth-child(even) td {
  background: var(--bg-soft);
}

/* Quick cards on home */
.quickcards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px;
  margin: 28px 0;
}
.qcard {
  background: var(--bg);
  color: var(--ink);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 26px 26px;
  display: flex; flex-direction: column; gap: 8px;
  transition: border-color .2s, transform .2s, box-shadow .2s;
  position: relative;
}
.qcard:hover {
  border-color: var(--accent);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}
.qcard::after {
  content: "\2192"; position: absolute; right: 24px; bottom: 18px;
  font-size: 18px; color: var(--accent);
}
.qcard .t {
  font-size: 18px; font-weight: 600;
  letter-spacing: 0.3px;
  color: var(--ink);
}
.qcard .s {
  font-size: 13px; color: var(--text-soft);
  letter-spacing: 0.3px;
}

/* Stats / feature strip */
.stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 32px;
  margin: 32px 0;
  padding: 36px 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.stat { text-align: left; padding: 0 4px; }
.stat .n {
  font-size: 28px; font-weight: 700;
  color: var(--accent);
  letter-spacing: 0.3px;
}
.stat .l {
  font-size: 13px; color: var(--text-soft);
  margin-top: 8px;
  letter-spacing: 0.3px;
}

/* Flowchart */
.flowchart img {
  margin: 0 auto;
  border-radius: var(--radius-lg);
}

/* ---------- Footer ---------- */
.sitefoot {
  background: var(--bg-soft);
  color: var(--text);
  border-top: 1px solid var(--line);
  margin-top: 64px;
}
.foot-in {
  max-width: var(--container);
  margin: 0 auto;
  padding: 52px 24px 32px;
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 40px;
  font-size: 14px;
}
.foot-in h4 {
  color: var(--ink);
  font-size: 14px;
  margin-bottom: 18px;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  font-weight: 600;
}
.foot-in a { color: var(--text); }
.foot-in a:hover { color: var(--accent); }
.foot-in .tel {
  font-size: 22px; font-weight: 700;
  color: var(--ink);
  letter-spacing: 0.3px;
}
.icp {
  border-top: 1px solid var(--line);
  text-align: center;
  padding: 22px;
  font-size: 13px;
  color: var(--text-soft);
  background: var(--bg);
}
.icp img {
  margin: 12px auto 0;
  width: 50px; height: 50px;
  border-radius: 4px;
}

/* ---------- Responsive ---------- */
@media (max-width: 960px) {
  .container {
    grid-template-columns: 1fr;
    margin-top: 28px;
    gap: 24px;
  }
}
@media (max-width: 860px) {
  .nav-toggle-btn {
    display: flex; justify-content: space-between; align-items: center;
  }
  .nav-in {
    display: none;
    padding: 4px 12px 12px;
    flex-direction: column;
    align-items: stretch;
  }
  .nav-toggle:checked ~ .nav-in { display: flex; }
  .mainnav a.navlink {
    border-bottom: 1px solid var(--line-soft);
    padding: 14px 18px;
    width: 100%;
  }
  .mainnav a.navlink.active {
    border-bottom-color: transparent;
    background: var(--accent-soft);
  }
  .section { margin-bottom: 28px; }
  .page-head { padding: 24px 0 18px; }
  .gallery {
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    gap: 12px;
  }
  .masthead { padding: 32px 0 20px; }
  .banner-box { gap: 0; }
  .masthead-in { padding: 0 4px; }
  .brand { gap: 18px; }
  .brand .logo { width: 88px; height: 88px; }
  .topbar-in {
    justify-content: center;
    font-size: 12.5px;
    gap: 4px 16px;
  }
}
@media (max-width: 600px) {
  .foot-in {
    grid-template-columns: 1fr;
    padding: 36px 24px 24px;
    gap: 28px;
  }
  .stats { gap: 20px; padding: 28px 0; }
  .container { padding: 0 16px; }
  .topbar-in { padding: 10px 16px; }
  .banner-box { padding: 0 16px; }
  .nav-in { padding: 0 16px; }
}