/* Oopbuy QC Photo Guide — hand-written stylesheet
   Positioning: an image-reading guide. Neutral white ground, slate-grey labels,
   deep sea-green links. Content-led, no decorative cover art. */

/* ---------- Tokens ---------- */
:root {
  --ink: #1b2420;
  --ink-soft: #3a463f;
  --muted: #5c6862;
  --faint: #808b85;
  --line: #e0e5e1;
  --line-strong: #cdd4ce;
  --bg: #ffffff;
  --bg-soft: #f5f7f5;
  --bg-panel: #f1f4f1;
  --accent: #0f5a4b;
  --accent-strong: #0b4438;
  --accent-tint: #e7f0ec;
  --note: #fbf6ea;
  --note-line: #e7dcbf;
  --stop: #7a2f26;

  --wrap: 1200px;
  --measure: 68ch;
  --radius: 6px;
  --radius-lg: 10px;

  --font: Inter, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Arial, sans-serif;

  --gap-section: 56px;
  --pad-side: 20px;
}

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.7;
  color: var(--ink);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--accent); text-decoration: underline; text-underline-offset: 2px; }
a:hover { color: var(--accent-strong); }
h1, h2, h3, h4 { color: var(--ink); margin: 0; text-wrap: balance; }
p { margin: 0; }
ul, ol { margin: 0; padding-left: 1.2em; }
figure { margin: 0; }
:focus-visible { outline: 3px solid var(--accent); outline-offset: 2px; border-radius: 3px; }

/* ---------- Layout ---------- */
.wrap { max-width: var(--wrap); margin-inline: auto; padding-inline: var(--pad-side); }
.skip {
  position: absolute; left: -9999px; top: 0; background: var(--accent); color: #fff;
  padding: 10px 16px; z-index: 20; border-radius: 0 0 var(--radius) 0;
}
.skip:focus { left: 0; }

main { display: block; }
.sections { display: flex; flex-direction: column; gap: var(--gap-section); }
.sections > section { min-width: 0; }
.page-pad { padding-block: 40px 64px; }

/* ---------- Header ---------- */
.site-header {
  border-bottom: 1px solid var(--line);
  background: var(--bg);
}
.header-inner {
  display: flex; align-items: center; flex-wrap: wrap;
  gap: 14px 22px; padding-block: 14px;
}
.brand {
  font-weight: 800; font-size: 17px; letter-spacing: -0.01em;
  color: var(--ink); text-decoration: none; line-height: 1.2; min-width: 0;
}
.brand span { color: var(--accent); }
.primary-nav { min-width: 0; }
.primary-nav ul {
  list-style: none; margin: 0; padding: 0;
  display: flex; flex-wrap: wrap; gap: 4px 6px;
}
.primary-nav a {
  display: inline-block; padding: 6px 10px; border-radius: var(--radius);
  font-size: 14px; font-weight: 500; color: var(--ink-soft); text-decoration: none;
}
.primary-nav a:hover { background: var(--bg-soft); color: var(--accent-strong); }
.primary-nav a[aria-current="page"] { color: var(--accent-strong); background: var(--accent-tint); }
.header-search { margin-left: auto; min-width: 0; }

/* ---------- Search ---------- */
.search-form { display: flex; gap: 6px; align-items: stretch; min-width: 0; }
.search-form input[type="search"] {
  font: inherit; font-size: 14px; padding: 7px 10px; min-width: 0; width: 100%;
  border: 1px solid var(--line-strong); border-radius: var(--radius); background: #fff; color: var(--ink);
}
.search-form.header-search-form input { width: 190px; max-width: 46vw; }
.btn {
  font: inherit; font-size: 15px; font-weight: 600; cursor: pointer;
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 9px 16px; border-radius: var(--radius); border: 1px solid transparent;
  text-decoration: none; line-height: 1.2; white-space: nowrap;
}
.btn-primary { background: var(--accent); color: #fff; border-color: var(--accent); }
.btn-primary:hover { background: var(--accent-strong); border-color: var(--accent-strong); color: #fff; }
.btn-ghost { background: #fff; color: var(--accent-strong); border-color: var(--line-strong); }
.btn-ghost:hover { background: var(--bg-soft); color: var(--accent-strong); }
.btn-sm { font-size: 14px; padding: 7px 12px; }
.btn-block { width: 100%; }
.search-hint { font-size: 13px; color: var(--muted); margin-top: 8px; }

/* ---------- Hero ---------- */
.hero { padding-block: 48px 8px; }
.hero .eyebrow {
  font-size: 13px; font-weight: 600; letter-spacing: 0.06em; text-transform: uppercase;
  color: var(--accent); margin-bottom: 14px;
}
.hero h1 {
  font-size: 48px; font-weight: 800; line-height: 1.15; letter-spacing: -0.02em;
  max-width: 16ch;
}
.hero .lede { font-size: 18px; color: var(--ink-soft); max-width: 60ch; margin-top: 18px; }
.hero .hero-q {
  margin-top: 22px; padding: 16px 18px; background: var(--bg-panel);
  border-left: 3px solid var(--accent); border-radius: 0 var(--radius) var(--radius) 0;
  font-size: 17px; color: var(--ink); max-width: 60ch;
}
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 24px; align-items: center; }

/* ---------- Section headings ---------- */
.section-head { max-width: var(--measure); }
.section-head h2 { font-size: 28px; font-weight: 700; line-height: 1.3; }
.section-head p { margin-top: 12px; color: var(--ink-soft); }
.section-kicker {
  font-size: 13px; font-weight: 600; letter-spacing: 0.05em; text-transform: uppercase;
  color: var(--faint); margin-bottom: 10px;
}

/* ---------- Prose ---------- */
.prose { max-width: var(--measure); }
.prose > * + * { margin-top: 20px; }
.prose h2 { font-size: 28px; line-height: 1.3; margin-top: 44px; }
.prose h3 { font-size: 18px; line-height: 1.4; margin-top: 32px; }
.prose ul, .prose ol { padding-left: 1.3em; }
.prose li + li { margin-top: 8px; }
.prose li { padding-left: 2px; }
.lead { font-size: 18px; color: var(--ink-soft); }

/* ---------- Cards / grids ---------- */
.grid { display: grid; gap: 20px; }
.grid-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.card {
  min-width: 0; border: 1px solid var(--line); border-radius: var(--radius-lg);
  background: #fff; padding: 18px; display: flex; flex-direction: column;
}
.card h3 { font-size: 18px; line-height: 1.35; }
.card p { color: var(--ink-soft); margin-top: 8px; font-size: 15px; }
.card .card-link { margin-top: auto; padding-top: 14px; font-weight: 600; font-size: 14px; }

/* ---------- Product cards ---------- */
.product-grid {
  display: grid; gap: 18px;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
}
.product-card {
  min-width: 0; border: 1px solid var(--line); border-radius: var(--radius-lg);
  overflow: hidden; background: #fff; display: flex; flex-direction: column;
}
.product-card .thumb {
  background: var(--bg-soft); aspect-ratio: 3 / 4; display: block; border-bottom: 1px solid var(--line);
}
.product-card .thumb img { width: 100%; height: 100%; object-fit: cover; }
.product-card .body { padding: 12px 14px 16px; display: flex; flex-direction: column; gap: 8px; flex: 1; }
.product-card .title {
  font-size: 15px; font-weight: 600; line-height: 1.4; color: var(--ink);
  text-decoration: none; overflow-wrap: anywhere;
}
.product-card .title:hover { color: var(--accent-strong); }
.product-card .price { font-size: 14px; color: var(--ink-soft); }
.product-card .price .usd { font-weight: 600; color: var(--ink); }
.product-card .tag {
  font-size: 12px; font-weight: 600; color: var(--muted);
  display: inline-flex; align-items: center; gap: 6px; margin-top: auto;
}
.tag-dot { width: 7px; height: 7px; border-radius: 50%; background: var(--accent); display: inline-block; }
.tag-dot.none { background: var(--line-strong); }

/* ---------- Callouts ---------- */
.callout {
  border: 1px solid var(--note-line); background: var(--note);
  border-radius: var(--radius-lg); padding: 18px 20px; max-width: var(--measure);
}
.callout.plain { background: var(--bg-soft); border-color: var(--line); }
.callout h3 { font-size: 17px; margin-bottom: 8px; }
.callout p + p { margin-top: 10px; }
.callout p, .callout li { color: var(--ink-soft); font-size: 15px; }

/* ---------- Breadcrumb ---------- */
.breadcrumb { font-size: 13px; color: var(--muted); padding-block: 18px 4px; }
.breadcrumb ol { list-style: none; display: flex; flex-wrap: wrap; gap: 6px; margin: 0; padding: 0; }
.breadcrumb li { display: flex; gap: 6px; align-items: center; }
.breadcrumb li + li::before { content: "/"; color: var(--line-strong); }
.breadcrumb a { color: var(--muted); text-decoration: none; }
.breadcrumb a:hover { color: var(--accent-strong); text-decoration: underline; }
.breadcrumb [aria-current="page"] { color: var(--ink-soft); }

/* ---------- Product page ---------- */
.product-head h1 { font-size: 34px; font-weight: 800; line-height: 1.2; margin-top: 8px; letter-spacing: -0.01em; }
.product-layout { display: grid; grid-template-columns: minmax(0, 360px) minmax(0, 1fr); gap: 32px; align-items: start; }
.product-figure { min-width: 0; }
.product-figure img {
  width: 100%; height: auto; border: 1px solid var(--line); border-radius: var(--radius-lg); background: var(--bg-soft);
}
.product-figure figcaption { font-size: 13px; color: var(--muted); margin-top: 8px; }
.product-main { min-width: 0; display: flex; flex-direction: column; gap: 22px; }
.price-block { border: 1px solid var(--line); border-radius: var(--radius-lg); padding: 16px 18px; background: #fff; }
.price-block .usd { font-size: 24px; font-weight: 800; color: var(--ink); }
.price-block .cny { font-size: 15px; color: var(--ink-soft); margin-top: 2px; }
.price-block .fx { font-size: 13px; color: var(--muted); margin-top: 10px; }
.source-cta { border: 1px solid var(--line-strong); border-radius: var(--radius-lg); padding: 18px 20px; background: var(--bg-soft); }
.source-cta h2 { font-size: 20px; }
.source-cta p { color: var(--ink-soft); margin-top: 10px; font-size: 15px; }
.source-cta .actions { margin-top: 16px; display: flex; flex-wrap: wrap; gap: 10px; }
.agent-list {
  margin-top: 12px; display: flex; flex-wrap: wrap; gap: 6px; list-style: none; padding: 0;
}
.agent-list li {
  font-size: 13px; color: var(--ink-soft); background: #fff;
  border: 1px solid var(--line); border-radius: 100px; padding: 3px 11px;
}

/* ---------- QC gallery ---------- */
.qc-section h2 { font-size: 22px; }
.qc-note { font-size: 14px; color: var(--muted); margin-top: 8px; max-width: var(--measure); }
.qc-gallery {
  margin-top: 16px; display: grid; gap: 12px;
  grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
}
.qc-gallery a {
  display: block; aspect-ratio: 1 / 1; border: 1px solid var(--line); border-radius: var(--radius);
  overflow: hidden; background: var(--bg-panel); min-width: 0;
}
.qc-gallery img { width: 100%; height: 100%; object-fit: contain; }
.empty-state {
  border: 1px dashed var(--line-strong); border-radius: var(--radius-lg);
  padding: 20px 22px; background: var(--bg-soft); max-width: var(--measure);
}
.empty-state p { color: var(--ink-soft); }
.empty-state p + p { margin-top: 10px; }

/* ---------- Definition rows ---------- */
.factlist { border-top: 1px solid var(--line); max-width: var(--measure); }
.factlist div { display: flex; gap: 16px; padding: 12px 0; border-bottom: 1px solid var(--line); }
.factlist dt { flex: 0 0 34%; font-weight: 600; color: var(--muted); font-size: 14px; }
.factlist dd { margin: 0; color: var(--ink-soft); font-size: 15px; min-width: 0; }

/* ---------- FAQ ---------- */
.faq-item { border-bottom: 1px solid var(--line); padding: 18px 0; max-width: var(--measure); }
.faq-item h3 { font-size: 18px; }
.faq-item p { margin-top: 8px; color: var(--ink-soft); }

/* ---------- Panel band ---------- */
.band { background: var(--bg-soft); border-block: 1px solid var(--line); padding-block: 44px; }
.band .sections { gap: 0; }

/* ---------- Footer ---------- */
.site-footer { border-top: 1px solid var(--line); background: var(--bg-soft); margin-top: 72px; }
.footer-inner { padding-block: 40px 48px; display: grid; gap: 22px; }
.footer-brand { font-weight: 800; font-size: 16px; color: var(--ink); }
.footer-nav ul { list-style: none; display: flex; flex-wrap: wrap; gap: 8px 20px; margin: 0; padding: 0; }
.footer-nav a { font-size: 14px; color: var(--ink-soft); text-decoration: none; }
.footer-nav a:hover { color: var(--accent-strong); text-decoration: underline; }
.footer-note { font-size: 13px; color: var(--muted); max-width: 80ch; }
.footer-note.flag { color: var(--stop); font-weight: 500; }

/* ---------- Utilities ---------- */
.tag-row { display: flex; flex-wrap: wrap; gap: 8px; }
.chip {
  font-size: 13px; font-weight: 500; color: var(--ink-soft);
  border: 1px solid var(--line); border-radius: 100px; padding: 4px 12px; text-decoration: none; background: #fff;
}
.chip:hover { border-color: var(--accent); color: var(--accent-strong); }
.muted { color: var(--muted); }
.small { font-size: 14px; }
.mt-24 { margin-top: 24px; }
.mt-32 { margin-top: 32px; }
.divider { border: 0; border-top: 1px solid var(--line); margin-block: 8px; }
.related-head { font-size: 20px; margin-bottom: 16px; }

/* ---------- Mobile ---------- */
@media (max-width: 900px) {
  .product-layout { grid-template-columns: 1fr; gap: 24px; }
  .product-figure { max-width: 360px; }
  .grid-3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 640px) {
  :root { --gap-section: 40px; }
  body { font-size: 15px; line-height: 1.6; }
  .header-inner { gap: 12px 16px; }
  .header-search { margin-left: 0; flex: 1 1 100%; }
  .search-form.header-search-form input { width: 100%; max-width: none; }
  .hero { padding-block: 32px 4px; }
  .hero h1 { font-size: 32px; line-height: 1.2; }
  .hero .lede { font-size: 16px; }
  .section-head h2, .prose h2 { font-size: 22px; }
  .product-head h1 { font-size: 26px; }
  .hero .hero-q { font-size: 16px; }
  .grid-3, .grid-2 { grid-template-columns: 1fr; }
  .product-grid { grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: 14px; }
  .qc-gallery { grid-template-columns: repeat(auto-fill, minmax(120px, 1fr)); gap: 10px; }
  .factlist dt { flex-basis: 42%; }
  .footer-inner { padding-block: 32px 40px; }
}
@media (max-width: 380px) {
  .product-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (prefers-reduced-motion: reduce) {
  * { animation-duration: 0.001ms !important; transition-duration: 0.001ms !important; }
}