/* ==========================================================================
   Xilemeng v2 — stylesheet
   Bigger, bolder, image-driven layout. Mobile-first, fully responsive.
   Brand: deep ocean blue + amber (oil) accents on clean white.
   ========================================================================== */
:root {
  --blue:      #0a5ca8;
  --blue-dark: #063f74;
  --blue-deep: #04294d;
  --blue-soft: #e9f2fb;
  --amber:     #f2a516;
  --amber-dk:  #d68a00;
  --ink:       #142430;
  --muted:     #56697a;
  --line:      #e4ebf2;
  --bg:        #ffffff;
  --bg-alt:    #f4f8fc;
  --green:     #17b26a;
  --green-dk:  #129155;
  --radius:    18px;
  --radius-sm: 12px;
  --shadow:    0 18px 50px rgba(8, 55, 100, .12);
  --shadow-sm: 0 6px 22px rgba(8, 55, 100, .08);
  --maxw:      1200px;
  --font:      "Segoe UI", Roboto, "Helvetica Neue", Arial,
               "PingFang SC", "Microsoft YaHei", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
img { max-width: 100%; display: block; }
a { color: var(--blue); text-decoration: none; }
h1, h2, h3, h4 { line-height: 1.15; }

.container {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 14px 28px;
  border-radius: 999px;
  font-weight: 700; font-size: 15px;
  cursor: pointer; border: 2px solid transparent;
  transition: transform .16s ease, box-shadow .16s ease, background .16s ease, color .16s ease;
  text-align: center; white-space: nowrap;
}
.btn:hover { transform: translateY(-2px); }
.btn-primary { background: var(--amber); color: #241a00; border-color: var(--amber); }
.btn-primary:hover { background: var(--amber-dk); border-color: var(--amber-dk); box-shadow: 0 12px 30px rgba(242,165,22,.4); }
.btn-ghost { background: rgba(255,255,255,.12); color: #fff; border-color: rgba(255,255,255,.5); }
.btn-ghost:hover { background: rgba(255,255,255,.2); }
.btn-order { background: var(--green); color: #fff; border-color: var(--green); width: 100%; }
.btn-order:hover { background: var(--green-dk); border-color: var(--green-dk); box-shadow: 0 12px 30px rgba(23,178,106,.35); }
.btn-lg { padding: 17px 36px; font-size: 17px; }
.btn-sm { padding: 10px 18px; font-size: 14px; }

/* ---------- header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255,255,255,.9);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid transparent;
  transition: box-shadow .2s ease, border-color .2s ease;
}
.site-header.scrolled { box-shadow: var(--shadow-sm); border-bottom-color: var(--line); }
.header-inner {
  display: flex; align-items: center; justify-content: space-between;
  height: 74px; gap: 18px;
}
.brand { display: flex; align-items: center; gap: 11px; }
.brand-logo { width: 44px; height: 44px; }
.brand-text { display: flex; flex-direction: column; line-height: 1.1; }
.brand-name { font-weight: 800; letter-spacing: .5px; color: var(--ink); font-size: 19px; }
.brand-cn { font-size: 12px; color: var(--blue); font-weight: 700; }
.brand-sub { display: none; font-size: 11px; color: var(--ink-light); font-weight: 500; }

.main-nav { display: flex; gap: 28px; margin-left: auto; }
.main-nav a { color: var(--ink); font-weight: 600; font-size: 15px; position: relative; }
.main-nav a::after {
  content: ""; position: absolute; left: 0; bottom: -6px; width: 0; height: 2px;
  background: var(--amber); transition: width .2s ease;
}
.main-nav a:hover { color: var(--blue); }
.main-nav a:hover::after { width: 100%; }

.header-tools { display: flex; align-items: center; gap: 14px; }
.lang-switch {
  display: flex; border: 1px solid var(--line);
  border-radius: 999px; overflow: hidden; background: #fff;
}
.lang-switch button {
  border: 0; background: #fff; padding: 8px 13px;
  font-size: 13px; font-weight: 700; color: var(--muted); cursor: pointer;
  transition: background .15s ease, color .15s ease;
}
.lang-switch button.active { background: var(--blue); color: #fff; }
.header-cta { display: inline-flex; }
.nav-toggle {
  display: none; border: 0; background: transparent;
  font-size: 28px; cursor: pointer; color: var(--ink); line-height: 1;
}

/* ---------- hero ---------- */
.hero {
  position: relative; overflow: hidden;
  background: linear-gradient(135deg, var(--blue-deep), var(--blue-dark) 55%, var(--blue));
  color: #fff;
  padding: 96px 0 108px;
}
.hero-bg {
  position: absolute; inset: 0;
  background:
    radial-gradient(700px 400px at 88% 8%, rgba(242,165,22,.22), transparent),
    radial-gradient(600px 500px at 10% 100%, rgba(255,255,255,.10), transparent);
  pointer-events: none;
}
.hero-inner {
  position: relative; z-index: 1;
  display: grid; grid-template-columns: 1.1fr .9fr;
  gap: 40px; align-items: center;
}
.hero-eyebrow {
  display: inline-block;
  color: var(--amber); font-weight: 800; letter-spacing: 1px;
  text-transform: uppercase; font-size: 13px; margin: 0 0 16px;
}
.hero-text h1 {
  font-size: clamp(34px, 5vw, 60px); font-weight: 900;
  margin: 0 0 20px; letter-spacing: -.5px;
}
.hero-sub { font-size: clamp(16px, 2vw, 20px); color: rgba(255,255,255,.85); margin: 0 0 32px; max-width: 560px; }
.hero-cta { display: flex; gap: 16px; flex-wrap: wrap; }
.hero-stats {
  display: grid; grid-template-columns: repeat(4, auto); gap: 34px;
  margin: 48px 0 0;
}
.hstat { display: flex; flex-direction: column; }
.hstat strong { font-size: 34px; font-weight: 900; color: var(--amber); line-height: 1; }
.hstat span { font-size: 13px; color: rgba(255,255,255,.8); margin-top: 6px; }

.hero-visual { position: relative; height: 420px; }
.hero-glow {
  position: absolute; width: 380px; height: 380px; border-radius: 50%;
  top: 50%; left: 50%; transform: translate(-50%, -50%);
  background: radial-gradient(circle, rgba(242,165,22,.30), transparent 65%);
}
.hero-visual .hv {
  position: absolute; filter: drop-shadow(0 22px 40px rgba(0,0,0,.35));
  animation: float 6s ease-in-out infinite;
}
.hv-1 { width: 210px; left: 14%; top: 8%;  z-index: 3; }
.hv-2 { width: 165px; left: 46%; top: 30%; z-index: 2; animation-delay: .8s; }
.hv-3 { width: 150px; left: 2%;  top: 46%; z-index: 1; animation-delay: 1.6s; }
@keyframes float {
  0%, 100% { transform: translateY(0); }
  50%      { transform: translateY(-16px); }
}

/* ---------- trust strip ---------- */
.trust-strip { background: var(--ink); color: #fff; }
.trust-inner {
  display: flex; flex-wrap: wrap; justify-content: center; gap: 14px 40px;
  padding: 18px 24px; font-size: 14px; font-weight: 600;
}
.trust-inner span { position: relative; padding-left: 26px; color: rgba(255,255,255,.92); }
.trust-inner span::before {
  content: "✓"; position: absolute; left: 0; color: var(--amber); font-weight: 900;
}

/* ---------- sections ---------- */
.section { padding: 92px 0; }
.section-alt { background: var(--bg-alt); }
.section-head { text-align: center; max-width: 760px; margin: 0 auto 56px; }
.kicker {
  display: inline-block; color: var(--blue); font-weight: 800;
  letter-spacing: 1px; text-transform: uppercase; font-size: 13px; margin-bottom: 12px;
}
.section-head h2 { font-size: clamp(26px, 3.5vw, 40px); font-weight: 900; margin: 0; letter-spacing: -.5px; }
.section-head p { color: var(--muted); font-size: 17px; margin: 0; }

/* ---------- category cards ---------- */
.cat-cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; }
.cat-card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  overflow: hidden; display: flex; flex-direction: column; color: var(--ink);
  transition: transform .2s ease, box-shadow .2s ease, border-color .2s ease;
}
.cat-card:hover { transform: translateY(-6px); box-shadow: var(--shadow); border-color: var(--blue); }
.cat-img {
  background: linear-gradient(160deg, var(--blue-soft), #fff);
  aspect-ratio: 16 / 11; display: flex; align-items: center; justify-content: center;
  padding: 26px;
}
.cat-img img { height: 100%; width: auto; object-fit: contain; }
.cat-info { padding: 26px 26px 30px; }
.cat-info h3 { font-size: 22px; font-weight: 800; margin: 0 0 10px; }
.cat-info p { color: var(--muted); font-size: 15px; margin: 0 0 16px; }
.cat-link { color: var(--blue); font-weight: 800; font-size: 15px; }
.cat-card:hover .cat-link { color: var(--amber-dk); }

/* ---------- category tabs ---------- */
.cat-tabs { display: flex; flex-wrap: wrap; justify-content: center; gap: 12px; margin-bottom: 42px; }
.cat-tab {
  border: 2px solid var(--line); background: #fff; color: var(--ink);
  padding: 11px 24px; border-radius: 999px; font-weight: 700; font-size: 15px; cursor: pointer;
  transition: all .16s ease;
}
.cat-tab:hover { border-color: var(--blue); color: var(--blue); }
.cat-tab.active { background: var(--blue); border-color: var(--blue); color: #fff; }

/* ---------- product grid ---------- */
.product-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 26px; }
.product-card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  overflow: hidden; display: flex; flex-direction: column;
  transition: transform .18s ease, box-shadow .18s ease, border-color .18s ease;
}
.product-card:hover { transform: translateY(-5px); box-shadow: var(--shadow); border-color: var(--blue); }
.pc-media {
  position: relative;
  background: linear-gradient(160deg, var(--blue-soft), #fbfdff);
  aspect-ratio: 1 / 1; display: flex; align-items: center; justify-content: center; padding: 22px;
}
.pc-media img { height: 100%; width: 100%; object-fit: contain; }
.pc-media img.is-fallback { padding: 6px; }
.pc-cat {
  position: absolute; top: 12px; left: 12px; z-index: 2;
  background: rgba(10,92,168,.92); color: #fff; font-size: 11px; font-weight: 700;
  padding: 4px 11px; border-radius: 999px; letter-spacing: .3px;
}
.pc-body { padding: 20px; display: flex; flex-direction: column; gap: 12px; flex: 1; }
.pc-head { display: flex; align-items: center; justify-content: space-between; gap: 8px; }
.pc-size { font-size: 24px; font-weight: 900; margin: 0; }
.pc-tag {
  font-size: 11px; font-weight: 700; color: var(--blue);
  background: var(--blue-soft); padding: 4px 10px; border-radius: 999px; white-space: nowrap;
}
.pc-price { display: flex; align-items: baseline; gap: 5px; }
.pc-price .cur { font-size: 14px; color: var(--muted); font-weight: 700; }
.pc-price .amt { font-size: 26px; font-weight: 900; color: var(--green-dk); }
.pc-price .per { font-size: 13px; color: var(--muted); }
.pc-meta { display: flex; justify-content: space-between; font-size: 13px; color: var(--muted); }
.pc-body .btn-order { margin-top: auto; }
.price-note { text-align: center; color: var(--muted); font-size: 13px; margin: 42px auto 0; max-width: 820px; }

/* ---------- features (why) ---------- */
.feature-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 26px; }
.feature {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 32px 26px; transition: transform .18s ease, box-shadow .18s ease;
}
.feature:hover { transform: translateY(-4px); box-shadow: var(--shadow-sm); }
.feature-icon {
  font-size: 30px; width: 62px; height: 62px; border-radius: 16px;
  display: flex; align-items: center; justify-content: center;
  background: var(--blue-soft); margin-bottom: 18px;
}
.feature h3 { font-size: 19px; margin: 0 0 10px; font-weight: 800; }
.feature p { color: var(--muted); font-size: 15px; margin: 0; }

/* ---------- about ---------- */
.about-inner { display: grid; grid-template-columns: 1.4fr .6fr; gap: 56px; align-items: center; }
.about-text p { color: var(--muted); font-size: 17px; margin: 0 0 16px; }
.about-text .kicker { font-size: 15px; }
.about-list { list-style: none; padding: 0; margin: 24px 0 0; }
.about-list li { padding-left: 30px; position: relative; margin-bottom: 12px; font-weight: 600; }
.about-list li::before {
  content: "✓"; position: absolute; left: 0; color: var(--green); font-weight: 900;
}
.about-stats { display: grid; gap: 18px; }
.stat {
  background: #fff; border: 1px solid var(--line);
  border-radius: var(--radius); padding: 26px; text-align: center;
}
.stat strong { display: block; font-size: 26px; color: var(--blue-dark); font-weight: 900; }
.stat span { font-size: 14px; color: var(--muted); }

/* ---------- contact ---------- */
.contact-grid { display: grid; grid-template-columns: 1.2fr .8fr; gap: 48px; align-items: start; }
.contact-row { display: flex; gap: 18px; margin-bottom: 30px; }
.contact-ico {
  font-size: 24px; width: 54px; height: 54px; flex: none; border-radius: 14px;
  display: flex; align-items: center; justify-content: center; background: var(--blue-soft);
}
.contact-row h4 { margin: 0 0 5px; font-size: 17px; }
.contact-row p { margin: 0 0 10px; color: var(--muted); }
.contact-qr {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 28px; text-align: center; box-shadow: var(--shadow-sm);
}
.contact-qr img { margin: 0 auto 14px; border-radius: 12px; }
.contact-qr p { color: var(--muted); font-size: 14px; margin: 0; }

/* ---------- footer ---------- */
.site-footer { background: var(--blue-deep); color: #b9c9d8; padding: 52px 0 32px; }
.footer-inner {
  display: grid; grid-template-columns: 1.4fr 1fr; gap: 28px; align-items: center;
}
.footer-brand { display: flex; align-items: center; gap: 16px; }
.footer-brand .brand-logo { }
.footer-brand .brand-name { color: #fff; font-size: 17px; font-weight: 800; }
.footer-brand p { margin: 5px 0 0; font-size: 14px; color: #8ba3b8; }
.footer-contact { text-align: right; font-size: 14px; }
.footer-contact p { margin: 3px 0; }
.footer-copy {
  grid-column: 1 / -1; border-top: 1px solid rgba(255,255,255,.12); padding-top: 22px;
  margin: 12px 0 0; font-size: 13px; color: #7690a6; text-align: center;
}

/* ---------- floating WhatsApp ---------- */
.wa-float {
  position: fixed; right: 22px; bottom: 22px; z-index: 200;
  width: 60px; height: 60px; border-radius: 50%;
  background: var(--green); color: #fff; font-size: 28px;
  display: flex; align-items: center; justify-content: center;
  box-shadow: 0 8px 24px rgba(23,178,106,.55);
  transition: transform .15s ease;
}
.wa-float:hover { transform: scale(1.1); }

/* ==========================================================================
   Responsive
   ========================================================================== */
@media (max-width: 1024px) {
  .product-grid { grid-template-columns: repeat(3, 1fr); }
  .hero-visual { height: 360px; }
}

@media (max-width: 900px) {
  .hero { padding: 72px 0 80px; }
  .hero-inner { grid-template-columns: 1fr; gap: 24px; }
  .hero-visual { display: none; }
  .hero-stats { gap: 24px; }
  .cat-cards { grid-template-columns: 1fr; max-width: 460px; margin: 0 auto; }
  .product-grid { grid-template-columns: repeat(2, 1fr); }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .about-inner { grid-template-columns: 1fr; gap: 34px; }
  .about-stats { grid-template-columns: repeat(3, 1fr); }
  .contact-grid { grid-template-columns: 1fr; }
  .footer-inner { grid-template-columns: 1fr; text-align: center; }
  .footer-brand { justify-content: center; }
  .footer-contact { text-align: center; }
}

@media (max-width: 720px) {
  .nav-toggle { display: block; }
  .header-cta { display: none; }
  .main-nav {
    position: absolute; top: 74px; left: 0; right: 0;
    background: #fff; border-bottom: 1px solid var(--line);
    flex-direction: column; gap: 0; padding: 8px 0; margin-left: 0;
    display: none; box-shadow: var(--shadow);
  }
  .main-nav.open { display: flex; }
  .main-nav a { padding: 14px 24px; border-bottom: 1px solid var(--bg-alt); }
  .main-nav a::after { display: none; }
  .section { padding: 60px 0; }
}

@media (max-width: 560px) {
  .product-grid { grid-template-columns: repeat(2, 1fr); gap: 16px; }
  .feature-grid { grid-template-columns: 1fr; }
  .about-stats { grid-template-columns: 1fr; }
  .hero-stats { grid-template-columns: repeat(2, 1fr); gap: 22px; }
  .brand-cn { display: none; }
  .brand-sub { display: block; font-size: 12px; color: var(--ink-light); margin-top: 2px; }
  .pc-body { padding: 16px; }
  .pc-size { font-size: 20px; }
  .pc-price .amt { font-size: 22px; }
  .hero-cta .btn { flex: 1; }
}