/* ============================================================
   BIGUILAI — Official Site Stylesheet (SEO-friendly rebuild)
   Brand tokens: Amber #E8853A / Charcoal #141414 / Cream #F2EDE4 / Steel #8A8781
   ============================================================ */

:root {
  --amber: #E8853A;
  --amber-dark: #C96A24;
  --charcoal: #141414;
  --charcoal-soft: #1E1E1E;
  --charcoal-line: #2A2A2A;
  --cream: #F2EDE4;
  --cream-deep: #E4DFD4;
  --steel: #8A8781;
  --ink: #3C4043;
  --white: #FFFFFF;
  --line: #E4E0D8;

  --font-en: 'Space Grotesk', 'Helvetica Neue', Arial, sans-serif;
  --font-cn: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;

  --maxw: 1200px;
  --radius: 4px;
  --shadow-card: 0 2px 16px rgba(0, 0, 0, .08);
  --shadow-hover: 0 12px 32px rgba(0, 0, 0, .16);
  --ease: cubic-bezier(.4, 0, .2, 1);
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-en);
  color: var(--charcoal);
  background: var(--white);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

img { max-width: 100%; display: block; height: auto; }
a { color: inherit; text-decoration: none; }

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

/* Accessibility helpers */
.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--amber);
  color: #fff;
  padding: 12px 20px;
  z-index: 200;
  font-weight: 700;
}
.skip-link:focus { left: 8px; top: 8px; }

.visually-hidden {
  position: absolute;
  width: 1px; height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

:focus-visible { outline: 2px solid var(--amber); outline-offset: 3px; }

/* ---------- Typography ---------- */
h1, h2, h3, h4 { line-height: 1.22; font-weight: 700; letter-spacing: -.012em; }
h1 { font-size: clamp(32px, 5vw, 58px); }
h2 { font-size: clamp(26px, 3.8vw, 40px); margin-bottom: 16px; }
h3 { font-size: 20px; margin-bottom: 10px; }
p { margin-bottom: 16px; }

.eyebrow {
  font-size: 12px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--amber);
  font-weight: 700;
  margin-bottom: 14px;
}

.section-lead {
  font-size: 17px;
  color: var(--ink);
  max-width: 720px;
  margin-bottom: 44px;
}

section { padding: 84px 0; }
.section-dark { background: var(--charcoal); color: var(--cream); }
.section-dark .section-lead { color: rgba(242, 237, 228, .68); }
.section-cream { background: var(--cream); }
.section-head { margin-bottom: 46px; }
.section-head.is-center { text-align: center; }
.section-head.is-center .section-lead { margin-left: auto; margin-right: auto; }

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(20, 20, 20, .96);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--charcoal-line);
}

.header-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
  height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand { display: flex; align-items: center; gap: 12px; }
.brand img { height: 40px; width: 40px; object-fit: contain; }
.brand-name { font-size: 21px; font-weight: 700; color: var(--cream); letter-spacing: .02em; }
.brand-name span { color: var(--amber); }

.nav { display: flex; align-items: center; gap: 30px; }
.nav a {
  color: rgba(242, 237, 228, .82);
  font-size: 15px;
  font-weight: 500;
  transition: color .2s var(--ease);
}
.nav a:hover, .nav a.is-active { color: var(--amber); }

.nav-toggle {
  display: none;
  background: none;
  border: 0;
  color: var(--cream);
  font-size: 26px;
  cursor: pointer;
  line-height: 1;
}

/* ---------- Breadcrumb ---------- */
.breadcrumb {
  background: var(--cream);
  border-bottom: 1px solid var(--line);
  font-size: 13px;
  padding: 13px 0;
}
.breadcrumb ol { list-style: none; display: flex; flex-wrap: wrap; gap: 9px; align-items: center; }
.breadcrumb li { color: var(--steel); }
.breadcrumb li::after { content: '/'; margin-left: 9px; color: var(--cream-deep); }
.breadcrumb li:last-child::after { content: ''; }
.breadcrumb a:hover { color: var(--amber); }
.breadcrumb [aria-current] { color: var(--charcoal); font-weight: 700; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 28px;
  font-size: 15px;
  font-weight: 700;
  border-radius: var(--radius);
  border: 2px solid transparent;
  cursor: pointer;
  transition: background .22s var(--ease), color .22s var(--ease), transform .22s var(--ease), border-color .22s var(--ease);
  font-family: inherit;
}
.btn-primary { background: var(--amber); color: var(--white); }
.btn-primary:hover { background: var(--amber-dark); transform: translateY(-2px); }
.btn-ghost { background: transparent; color: var(--cream); border-color: rgba(242, 237, 228, .4); }
.btn-ghost:hover { border-color: var(--amber); color: var(--amber); }
.btn-dark { background: var(--charcoal); color: var(--cream); }
.btn-dark:hover { background: #000; transform: translateY(-2px); }
.btn-block { width: 100%; }

/* ---------- Hero ---------- */
.hero {
  position: relative;
  background: var(--charcoal);
  color: var(--cream);
  padding: 100px 0 92px;
  overflow: hidden;
}
.hero::after {
  content: '';
  position: absolute;
  right: -180px; top: -180px;
  width: 620px; height: 620px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(232, 133, 58, .22) 0%, rgba(232, 133, 58, 0) 68%);
  pointer-events: none;
}
.hero-inner {
  position: relative; z-index: 2;
  max-width: var(--maxw); margin: 0 auto; padding: 0 24px;
  display: grid; grid-template-columns: 1.15fr .85fr; gap: 56px; align-items: center;
}
.hero h1 em { font-style: normal; color: var(--amber); }
.hero-sub { font-size: 18px; color: rgba(242, 237, 228, .74); max-width: 560px; margin-bottom: 34px; }
.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; margin-bottom: 40px; }
.hero-stats {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px;
  padding-top: 32px; border-top: 1px solid var(--charcoal-line);
}
.hero-stats div strong { display: block; font-size: 28px; color: var(--amber); line-height: 1.1; }
.hero-stats div span { font-size: 12px; letter-spacing: .1em; text-transform: uppercase; color: rgba(242, 237, 228, .6); }

.hero-badge {
  justify-self: center; text-align: center;
  padding: 36px 30px;
  border: 1px solid var(--charcoal-line); border-radius: var(--radius);
  background: rgba(255, 255, 255, .03);
}
.hero-badge img { width: 148px; margin: 0 auto 18px; }
.hero-badge p { font-size: 13px; letter-spacing: .14em; text-transform: uppercase; color: var(--steel); }
.hero-badge .tagline { margin-top: 12px; font-size: 15px; letter-spacing: .06em; color: var(--amber); text-transform: none; font-weight: 700; }

/* ---------- Page hero (inner) ---------- */
.page-hero { background: var(--charcoal); color: var(--cream); padding: 68px 0 60px; text-align: center; }
.page-hero h1 { font-size: clamp(30px, 4.4vw, 50px); margin-bottom: 14px; }
.page-hero p { font-size: 17px; color: rgba(242, 237, 228, .68); max-width: 700px; margin: 0 auto; }
.page-hero .page-hero-narrow { max-width: 820px; margin: 0 auto; text-align: left; }

/* ---------- Product grid / cards ---------- */
.product-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; }

.product-card {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  display: flex; flex-direction: column;
  transition: transform .25s var(--ease), box-shadow .25s var(--ease);
}
.product-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-hover); }

.product-thumb {
  aspect-ratio: 4 / 3;
  background: linear-gradient(140deg, #2A2A2A 0%, #141414 100%);
  display: flex; align-items: center; justify-content: center;
  position: relative;
}
.product-thumb svg { width: 46%; height: auto; opacity: .92; }

.product-hot {
  position: absolute; top: 14px; left: 14px;
  background: var(--amber); color: var(--white);
  font-size: 11px; font-weight: 700; letter-spacing: .1em;
  padding: 5px 11px; border-radius: 2px; text-transform: uppercase;
}

.product-body { padding: 24px; flex: 1; display: flex; flex-direction: column; }
.product-body .cn { font-family: var(--font-cn); font-size: 13px; color: var(--steel); margin-bottom: 12px; }
.product-body p { font-size: 14px; color: #5C6063; }

.spec-list { list-style: none; margin-bottom: 20px; }
.spec-list li {
  font-size: 13px; color: #6A6E71;
  padding: 6px 0 6px 18px; position: relative;
  border-top: 1px dashed var(--line);
}
.spec-list li::before {
  content: ''; position: absolute; left: 0; top: 13px;
  width: 6px; height: 6px; background: var(--amber); border-radius: 50%;
}

.card-actions { margin-top: auto; display: flex; gap: 10px; }
.card-actions .btn { flex: 1; padding: 11px 14px; font-size: 14px; }

/* ---------- Why us ---------- */
.why-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 26px; }
.why-item {
  padding: 30px 26px;
  background: rgba(255, 255, 255, .04);
  border: 1px solid var(--charcoal-line);
  border-radius: var(--radius);
}
.why-item .num { font-size: 13px; font-weight: 700; color: var(--amber); letter-spacing: .14em; margin-bottom: 12px; }
.why-item h3 { font-size: 18px; margin-bottom: 10px; color: var(--cream); }
.why-item p { font-size: 14px; color: rgba(242, 237, 228, .62); }

/* Light variant */
.why-grid.is-light .why-item { background: var(--white); border-color: var(--line); }
.why-grid.is-light .why-item h3 { color: var(--charcoal); }
.why-grid.is-light .why-item p { color: var(--ink); }

/* ---------- Bundles ---------- */
.bundle { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.bundle-card {
  border: 2px solid var(--line); border-radius: var(--radius);
  padding: 32px 28px; position: relative; background: var(--white);
}
.bundle-card.is-featured { border-color: var(--amber); }
.bundle-card .ribbon {
  position: absolute; top: -13px; right: 24px;
  background: var(--amber); color: var(--white);
  font-size: 11px; font-weight: 700; letter-spacing: .1em; padding: 5px 12px;
}
.bundle-card h3 { font-size: 21px; margin-bottom: 6px; }
.bundle-card .for { font-size: 13px; color: var(--steel); margin-bottom: 18px; }
.bundle-card ul { list-style: none; margin-bottom: 22px; }
.bundle-card ul li { font-size: 14px; padding: 7px 0 7px 22px; position: relative; color: #5C6063; }
.bundle-card ul li::before { content: '✓'; position: absolute; left: 0; color: var(--amber); font-weight: 700; }

/* ---------- Split ---------- */
.split { display: grid; grid-template-columns: 1fr 1fr; gap: 56px; align-items: center; }
.split-visual {
  aspect-ratio: 4 / 3;
  background: linear-gradient(140deg, var(--amber) 0%, var(--amber-dark) 100%);
  border-radius: var(--radius);
  display: flex; align-items: center; justify-content: center;
}
.split-visual svg { width: 52%; opacity: .95; }
.split ul { list-style: none; margin: 22px 0 30px; }
.split ul li {
  padding: 12px 0 12px 30px; position: relative;
  border-bottom: 1px solid rgba(255, 255, 255, .1);
  color: rgba(242, 237, 228, .82); font-size: 15px;
}
.split ul li:last-child { border-bottom: 0; }
.split ul li::before { content: '→'; position: absolute; left: 0; color: var(--amber); font-weight: 700; }

/* ---------- FAQ ---------- */
.faq { max-width: 860px; margin: 0 auto; }
.faq-item { border-bottom: 1px solid var(--cream-deep); }
.faq-q {
  width: 100%; text-align: left; background: none; border: 0;
  padding: 22px 40px 22px 0; font-size: 17px; font-weight: 700;
  font-family: inherit; cursor: pointer; position: relative; color: var(--charcoal);
}
.faq-q::after {
  content: '+'; position: absolute; right: 4px; top: 50%;
  transform: translateY(-50%); font-size: 24px; color: var(--amber);
  transition: transform .25s var(--ease);
}
.faq-item.is-open .faq-q::after { transform: translateY(-50%) rotate(45deg); }
.faq-a { max-height: 0; overflow: hidden; transition: max-height .3s var(--ease); }
.faq-a p { padding: 0 40px 24px 0; font-size: 15px; color: #5C6063; }

/* ---------- Inquiry ---------- */
.inquiry { background: var(--charcoal); color: var(--cream); }
.inquiry-grid { display: grid; grid-template-columns: .9fr 1.1fr; gap: 56px; align-items: start; }
.inquiry h2 { color: var(--cream); }
.inquiry .section-lead { color: rgba(242, 237, 228, .68); }

.contact-direct { list-style: none; }
.contact-direct li {
  padding: 14px 0; border-top: 1px solid var(--charcoal-line);
  font-size: 15px; color: rgba(242, 237, 228, .8); display: flex; gap: 14px;
}
.contact-direct li strong {
  color: var(--amber); min-width: 92px; font-size: 12px;
  letter-spacing: .1em; text-transform: uppercase; padding-top: 3px;
}

form.inquiry-form {
  background: rgba(255, 255, 255, .04);
  border: 1px solid var(--charcoal-line);
  border-radius: var(--radius); padding: 32px;
}
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.field { margin-bottom: 16px; }
.field label {
  display: block; font-size: 12px; letter-spacing: .1em;
  text-transform: uppercase; color: var(--steel); margin-bottom: 7px; font-weight: 700;
}
.field input, .field select, .field textarea {
  width: 100%; padding: 12px 14px;
  background: rgba(255, 255, 255, .06);
  border: 1px solid var(--charcoal-line); border-radius: var(--radius);
  color: var(--cream); font-size: 15px; font-family: inherit;
  transition: border-color .2s var(--ease);
}
.field input::placeholder, .field textarea::placeholder { color: rgba(138, 135, 129, .8); }
.field input:focus, .field select:focus, .field textarea:focus { outline: none; border-color: var(--amber); }
.field select option { background: var(--charcoal); }
.field textarea { resize: vertical; min-height: 104px; }
.form-note { font-size: 12px; color: var(--steel); margin-top: 12px; margin-bottom: 0; }
.form-status { margin-top: 16px; font-size: 14px; font-weight: 700; display: none; margin-bottom: 0; }
.form-status.is-visible { display: block; }

/* ---------- Blog cards ---------- */
.post-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; }

.post-card {
  border: 1px solid var(--line); border-radius: var(--radius);
  overflow: hidden; background: var(--white);
  display: flex; flex-direction: column;
  transition: transform .25s var(--ease), box-shadow .25s var(--ease);
}
.post-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-hover); }
.post-thumb {
  aspect-ratio: 16 / 9;
  background: linear-gradient(140deg, #2A2A2A 0%, #141414 100%);
  display: flex; align-items: center; justify-content: center;
}
.post-thumb svg { width: 30%; opacity: .9; }
.post-body { padding: 24px; display: flex; flex-direction: column; flex: 1; }
.post-meta { font-size: 12px; letter-spacing: .1em; text-transform: uppercase; color: var(--steel); margin-bottom: 10px; }
.post-body h2, .post-body h3 { font-size: 19px; margin-bottom: 10px; line-height: 1.3; }
.post-body p { font-size: 14px; color: #5C6063; }
.post-more { margin-top: auto; font-size: 14px; font-weight: 700; color: var(--amber); }

/* ---------- Article layout ---------- */
.article-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 280px;
  gap: 56px;
  align-items: start;
}

.article-body { max-width: 760px; }
.article-body h2 { font-size: 27px; margin: 44px 0 14px; }
.article-body h3 { font-size: 20px; margin: 30px 0 10px; }
.article-body p { font-size: 16.5px; color: #45494C; }
.article-body ul, .article-body ol { margin: 0 0 20px 22px; }
.article-body li { font-size: 16.5px; color: #45494C; margin-bottom: 8px; }
.article-body strong { color: var(--charcoal); }

.article-lead {
  font-size: 19px;
  color: var(--ink);
  border-left: 3px solid var(--amber);
  padding-left: 18px;
  margin-bottom: 32px;
}

.article-tip {
  background: var(--cream);
  border-radius: var(--radius);
  padding: 22px 24px;
  margin: 28px 0;
}
.article-tip h4 { font-size: 15px; letter-spacing: .1em; text-transform: uppercase; color: var(--amber); margin-bottom: 10px; }
.article-tip p:last-child, .article-tip ul:last-child { margin-bottom: 0; }

.article-byline {
  display: flex; align-items: center; gap: 14px;
  font-size: 14px; color: var(--steel);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  padding: 16px 0;
  margin-bottom: 32px;
  flex-wrap: wrap;
}

.article-cta {
  background: var(--charcoal);
  color: var(--cream);
  border-radius: var(--radius);
  padding: 34px 32px;
  margin: 44px 0 0;
}
.article-cta h3 { color: var(--cream); font-size: 22px; }
.article-cta p { color: rgba(242, 237, 228, .7); }

/* Sidebar */
.sidebar { position: sticky; top: 96px; }
.sidebar-box {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px;
  margin-bottom: 24px;
  background: var(--white);
}
.sidebar-box h4 {
  font-size: 12px; letter-spacing: .14em; text-transform: uppercase;
  color: var(--steel); margin-bottom: 16px;
}
.toc { list-style: none; }
.toc li { margin-bottom: 10px; }
.toc a { font-size: 14.5px; color: #5C6063; transition: color .2s var(--ease); display: block; }
.toc a:hover, .toc a.is-active { color: var(--amber); }

.sidebar-links { list-style: none; }
.sidebar-links li { margin-bottom: 12px; }
.sidebar-links a { font-size: 14.5px; }
.sidebar-links a:hover { color: var(--amber); }

/* ---------- Spec table ---------- */
.spec-table { width: 100%; border-collapse: collapse; font-size: 15px; }
.spec-table th, .spec-table td { text-align: left; padding: 13px 16px; border-bottom: 1px solid var(--line); }
.spec-table th { background: var(--cream); font-size: 12px; letter-spacing: .1em; text-transform: uppercase; }
.spec-table td:first-child { font-weight: 700; width: 32%; }
.spec-table caption { caption-side: top; text-align: left; font-size: 13px; color: var(--steel); padding-bottom: 10px; }

/* ---------- Timeline ---------- */
.timeline { max-width: 820px; margin: 0 auto; }
.timeline-item {
  display: grid; grid-template-columns: 110px 1fr; gap: 24px;
  padding: 22px 0; border-bottom: 1px solid var(--charcoal-line);
}
.timeline-item .year { font-size: 22px; font-weight: 700; color: var(--amber); }
.timeline-item h3 { font-size: 17px; margin-bottom: 6px; color: var(--cream); }
.timeline-item p { font-size: 14px; color: rgba(242, 237, 228, .62); }

/* ---------- Footer ---------- */
.site-footer { background: #0D0D0D; color: rgba(242, 237, 228, .6); padding: 56px 0 28px; }
.footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1fr; gap: 40px; margin-bottom: 40px; }
.footer-brand img { height: 44px; width: 44px; margin-bottom: 14px; }
.footer-brand p { font-size: 14px; max-width: 300px; }
.footer-col h2, .footer-col h4 {
  font-size: 12px; letter-spacing: .14em; text-transform: uppercase;
  color: var(--cream); margin-bottom: 16px;
}
.footer-col a, .footer-col li { display: block; font-size: 14px; padding: 5px 0; }
.footer-col a:hover { color: var(--amber); }
.footer-col ul { list-style: none; }
.footer-bottom {
  border-top: 1px solid var(--charcoal-line); padding-top: 22px; font-size: 13px;
  display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap;
}

/* ---------- Responsive ---------- */
@media (max-width: 1000px) {
  .article-layout { grid-template-columns: 1fr; gap: 40px; }
  .sidebar { position: static; }
  .hero-inner { grid-template-columns: 1fr; }
  .hero-badge { display: none; }
  .product-grid, .why-grid, .bundle, .post-grid { grid-template-columns: repeat(2, 1fr); }
  .inquiry-grid, .split { grid-template-columns: 1fr; gap: 36px; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 720px) {
  section { padding: 60px 0; }
  .nav {
    display: none; position: absolute; top: 72px; left: 0; right: 0;
    background: var(--charcoal); flex-direction: column; align-items: flex-start;
    padding: 20px 24px 28px; gap: 18px; border-bottom: 1px solid var(--charcoal-line);
  }
  .nav.is-open { display: flex; }
  .nav-toggle { display: block; }
  .product-grid, .why-grid, .bundle, .post-grid { grid-template-columns: 1fr; }
  .hero-stats { grid-template-columns: repeat(2, 1fr); gap: 24px; }
  .form-row { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; gap: 28px; }
  .timeline-item { grid-template-columns: 1fr; gap: 6px; }
  .article-body h2 { font-size: 24px; }
}