/* ============================================================
   Masterbatch site — shared stylesheet
   结构参考：dcmasterbatch.com（独立站）+ Xinyeda（Made-in-China 店）
   GEO 增强：规格全数字、适用/不适用分区、FAQ、JSON-LD
   ============================================================ */

:root {
  --ink: #12222e;
  --ink-2: #40566a;
  --ink-3: #6b7f90;
  --line: #dde5eb;
  --bg: #ffffff;
  --bg-alt: #f6f8fa;
  --brand: #0f3b57;
  --brand-2: #1a5f86;
  --accent: #c2571a;
  --ok: #1e7d4f;
  --warn: #b3261e;
  --radius: 6px;
  --max: 1120px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.65;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

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

a { color: var(--brand-2); text-decoration: none; }
a:hover { text-decoration: underline; }

.wrap { max-width: var(--max); margin: 0 auto; padding: 0 24px; }

/* ---------- Header ---------- */
.site-header {
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
  background: rgba(255,255,255,.97);
  backdrop-filter: blur(6px);
  z-index: 50;
}
.site-header .wrap {
  display: flex;
  align-items: center;
  gap: 28px;
  min-height: 66px;
  flex-wrap: wrap;
}
.logo {
  font-weight: 700;
  font-size: 19px;
  color: var(--brand);
  letter-spacing: -.2px;
}
.logo span { color: var(--accent); }
.logo:hover { text-decoration: none; }

.nav { display: flex; gap: 22px; flex-wrap: wrap; margin-left: auto; }
.nav a {
  color: var(--ink-2);
  font-size: 14.5px;
  font-weight: 500;
  padding: 4px 0;
  border-bottom: 2px solid transparent;
}
.nav a:hover, .nav a.active {
  color: var(--brand);
  border-bottom-color: var(--accent);
  text-decoration: none;
}
.btn {
  display: inline-block;
  background: var(--accent);
  color: #fff;
  padding: 11px 20px;
  border-radius: var(--radius);
  font-size: 14.5px;
  font-weight: 600;
  border: 1px solid var(--accent);
  cursor: pointer;
  transition: background .15s;
}
.btn:hover { background: #a8490f; text-decoration: none; color: #fff; }
.btn.ghost {
  background: transparent;
  color: var(--brand);
  border-color: var(--line);
}
.btn.ghost:hover { background: var(--bg-alt); color: var(--brand); }

/* ---------- Hero ---------- */
.hero {
  background: linear-gradient(180deg, #f3f7fa 0%, #ffffff 100%);
  padding: 66px 0 54px;
  border-bottom: 1px solid var(--line);
}
.hero .eyebrow {
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 14px;
}
.hero h1 {
  font-size: 40px;
  line-height: 1.22;
  letter-spacing: -.8px;
  color: var(--brand);
  max-width: 800px;
  margin-bottom: 18px;
}
.hero .lede {
  font-size: 17.5px;
  color: var(--ink-2);
  max-width: 700px;
  margin-bottom: 26px;
}
.hero-actions { display: flex; gap: 12px; flex-wrap: wrap; }

/* ---------- Stats strip ---------- */
.stats {
  border-bottom: 1px solid var(--line);
  background: var(--bg);
}
.stats .wrap {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  background: var(--line);
}
.stat {
  background: #fff;
  padding: 26px 20px;
  text-align: center;
}
.stat b {
  display: block;
  font-size: 25px;
  color: var(--brand);
  letter-spacing: -.4px;
}
.stat span { font-size: 13px; color: var(--ink-3); }

/* ---------- Section ---------- */
.section { padding: 62px 0; }
.section.alt { background: var(--bg-alt); }
.section-head { margin-bottom: 34px; max-width: 760px; }
.section-head h2 {
  font-size: 28px;
  letter-spacing: -.5px;
  color: var(--brand);
  margin-bottom: 10px;
}
.section-head p { color: var(--ink-2); font-size: 16px; }

/* ---------- Cards ---------- */
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 22px; }

.card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px;
  background: #fff;
}
.card h3 {
  font-size: 18px;
  color: var(--brand);
  margin-bottom: 8px;
  letter-spacing: -.2px;
}
.card p { color: var(--ink-2); font-size: 14.8px; }

.product-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: #fff;
  display: flex;
  flex-direction: column;
}
.product-card:hover { border-color: var(--brand-2); }
.product-card .thumb {
  height: 168px;
  background: var(--bg-alt);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--ink-3);
  font-size: 12.5px;
  text-align: center;
  padding: 12px;
  border-bottom: 1px solid var(--line);
}
.product-card .body { padding: 20px; flex: 1; display: flex; flex-direction: column; }
.product-card h3 { font-size: 17px; color: var(--brand); margin-bottom: 6px; }
.product-card .spec-line {
  font-size: 13.5px;
  color: var(--ink-2);
  margin-bottom: 14px;
}
.product-card .more {
  margin-top: auto;
  font-weight: 600;
  font-size: 14px;
  color: var(--accent);
}

/* ---------- Tables ---------- */
table.spec {
  width: 100%;
  border-collapse: collapse;
  font-size: 14.5px;
  margin: 8px 0 6px;
  border: 1px solid var(--line);
}
table.spec th, table.spec td {
  text-align: left;
  padding: 11px 14px;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
}
table.spec th {
  background: var(--bg-alt);
  font-weight: 600;
  color: var(--ink);
  width: 38%;
  border-right: 1px solid var(--line);
}
table.spec tr:last-child th,
table.spec tr:last-child td { border-bottom: none; }
.spec-note {
  font-size: 12.8px;
  color: var(--ink-3);
  margin-top: 8px;
}

/* ---------- Quick facts bar ---------- */
.quickfacts {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  margin: 0 0 34px;
  background: var(--bg-alt);
}
.quickfacts div {
  padding: 13px 14px;
  border-right: 1px solid var(--line);
}
.quickfacts div:last-child { border-right: none; }
.quickfacts dt {
  font-size: 11.5px;
  text-transform: uppercase;
  letter-spacing: .06em;
  color: var(--ink-3);
  margin-bottom: 3px;
}
.quickfacts dd { font-size: 14px; font-weight: 600; color: var(--ink); }

/* ---------- Suitability two-column ---------- */
.fit { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; margin: 10px 0 8px; }
.fit-box {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px;
}
.fit-box.yes { border-left: 3px solid var(--ok); }
.fit-box.no { border-left: 3px solid var(--warn); }
.fit-box h4 {
  font-size: 14px;
  text-transform: uppercase;
  letter-spacing: .05em;
  margin-bottom: 10px;
}
.fit-box.yes h4 { color: var(--ok); }
.fit-box.no h4 { color: var(--warn); }
.fit-box ul { list-style: none; font-size: 14.5px; color: var(--ink-2); }
.fit-box li { padding: 5px 0 5px 20px; position: relative; }
.fit-box.yes li::before {
  content: "✓"; position: absolute; left: 0; color: var(--ok); font-weight: 700;
}
.fit-box.no li::before {
  content: "✕"; position: absolute; left: 0; color: var(--warn); font-weight: 700;
}

/* ---------- FAQ ---------- */
.faq details {
  border-bottom: 1px solid var(--line);
  padding: 16px 0;
}
.faq summary {
  cursor: pointer;
  font-weight: 600;
  font-size: 15.5px;
  color: var(--brand);
  list-style: none;
  position: relative;
  padding-right: 28px;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: "+"; position: absolute; right: 0; top: -2px;
  font-size: 20px; color: var(--accent); font-weight: 400;
}
.faq details[open] summary::after { content: "−"; }
.faq p { margin-top: 10px; color: var(--ink-2); font-size: 15px; }

/* ---------- Prose ---------- */
.prose h2 {
  font-size: 24px; color: var(--brand); letter-spacing: -.4px;
  margin: 38px 0 12px;
}
.prose h3 { font-size: 18px; color: var(--brand); margin: 26px 0 8px; }
.prose p { margin-bottom: 14px; color: var(--ink-2); }
.prose ul, .prose ol { margin: 0 0 16px 22px; color: var(--ink-2); }
.prose li { margin-bottom: 7px; }

/* ---------- CTA band ---------- */
.cta-band {
  background: var(--brand);
  color: #fff;
  padding: 52px 0;
}
.cta-band h2 { font-size: 27px; letter-spacing: -.5px; margin-bottom: 10px; }
.cta-band p { color: #c9dae6; margin-bottom: 22px; max-width: 720px; }
.cta-band .btn { background: var(--accent); border-color: var(--accent); }

/* ---------- Form ---------- */
.form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.field { display: flex; flex-direction: column; }
.field.full { grid-column: 1 / -1; }
.field label {
  font-size: 13px; font-weight: 600; margin-bottom: 6px; color: var(--ink);
}
.field input, .field textarea, .field select {
  font: inherit;
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
  color: var(--ink);
}
.field input:focus, .field textarea:focus, .field select:focus {
  outline: none; border-color: var(--brand-2);
}
.field textarea { resize: vertical; min-height: 110px; }

/* ---------- Breadcrumb ---------- */
.crumb {
  font-size: 13px;
  color: var(--ink-3);
  padding: 18px 0 0;
}
.crumb a { color: var(--ink-3); }

/* ---------- Photo placeholder ---------- */
.photo-ph {
  border: 1px dashed var(--line);
  border-radius: var(--radius);
  background: var(--bg-alt);
  min-height: 190px;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 18px;
  color: var(--ink-3);
  font-size: 12.5px;
  line-height: 1.5;
}

/* ---------- Notice ---------- */
.draft-note {
  background: #fff6e8;
  border: 1px solid #f0d5ac;
  border-radius: var(--radius);
  padding: 12px 16px;
  font-size: 13px;
  color: #7a4b12;
  margin: 20px 0 0;
}

/* ---------- Footer ---------- */
.site-footer {
  border-top: 1px solid var(--line);
  padding: 44px 0 30px;
  font-size: 14px;
  color: var(--ink-3);
  background: var(--bg-alt);
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1fr;
  gap: 28px;
  margin-bottom: 26px;
}
.footer-grid h5 {
  font-size: 13px; text-transform: uppercase; letter-spacing: .07em;
  color: var(--ink); margin-bottom: 10px;
}
.footer-grid ul { list-style: none; font-size: 14px; }
.footer-grid li { margin-bottom: 6px; }
.footer-grid a { color: var(--ink-2); }
.footer-bottom {
  border-top: 1px solid var(--line);
  padding-top: 18px;
  font-size: 12.5px;
  display: flex;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

/* ---------- Responsive ---------- */
@media (max-width: 900px) {
  .stats .wrap { grid-template-columns: repeat(2, 1fr); }
  .grid-3, .grid-2, .fit, .form-grid { grid-template-columns: 1fr; }
  .quickfacts { grid-template-columns: repeat(2, 1fr); }
  .quickfacts div { border-bottom: 1px solid var(--line); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .hero h1 { font-size: 31px; }
  .nav { margin-left: 0; gap: 16px; }
}
@media (max-width: 560px) {
  .stats .wrap { grid-template-columns: 1fr; }
  .hero { padding: 44px 0 38px; }
  .section { padding: 44px 0; }
}