/* ══════════════════════════════════════════════════════════════════
   DUMAI TUBE - GLOBAL UNIVERSAL HEADER & FOOTER DESIGN SYSTEM
   Single Source of Truth across all site pages
   Est. 2016 · Shanghai Manufacturing Base
   ══════════════════════════════════════════════════════════════════ */

@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Mono:wght@400;500;600&family=Inter:wght@400;500;600;700;800&family=Plus+Jakarta+Sans:wght@600;700;800&display=swap');

:root {
  --dumai-navy-950: #080e18;
  --dumai-navy-900: #0d1627;
  --dumai-navy-850: #0f2445;
  --dumai-navy-800: #14223d;
  --dumai-navy-700: #1e3256;
  --dumai-blue-primary: #252e80;
  --dumai-blue-hover: #1a2266;
  --dumai-teal: #4ebdc1;
  --dumai-teal-hover: #3ba8ac;
  --dumai-teal-dark: #288488;
  --dumai-border-subtle: #e2dfda;
  --dumai-border-light: #e2e8f0;
  --dumai-text-primary: #091629;
  --dumai-text-secondary: #4b5563;
  --dumai-text-muted: #64748b;
  --dumai-font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --dumai-font-display: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, sans-serif;
  --dumai-font-mono: 'IBM Plex Mono', Menlo, Consolas, monospace;
}

/* Base Isolation for Header & Footer Elements */
.top-utility,
.site-header,
.mobile-nav-drawer,
.mobile-nav-overlay,
.site-footer {
  box-sizing: border-box;
  font-family: var(--dumai-font-sans);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.top-utility *,
.site-header *,
.mobile-nav-drawer *,
.mobile-nav-overlay *,
.site-footer * {
  box-sizing: border-box;
}

/* ══════════════════════════════════════════════
   1. TOP BRAND UTILITY BAR (Global B2B Supply)
══════════════════════════════════════════════ */
.top-utility {
  background-color: var(--dumai-navy-950);
  color: #94a3b8;
  font-size: 11.5px;
  height: 38px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  position: relative;
  z-index: 1001;
  width: 100%;
}

.utility-container {
  max-width: 1440px;
  margin: 0 auto;
  padding: 0 clamp(20px, 4vw, 64px);
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.utility-left {
  display: flex;
  align-items: center;
  gap: 8px;
  color: #cbd5e1;
  font-weight: 600;
  letter-spacing: 0.04em;
  font-size: 11.5px;
}

.utility-left-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--dumai-teal);
  display: inline-block;
  box-shadow: 0 0 6px var(--dumai-teal);
}

.utility-search-box {
  display: flex;
  align-items: center;
  gap: 8px;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 4px;
  padding: 4px 12px;
  width: 240px;
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}

.utility-search-box:focus-within {
  background: rgba(255, 255, 255, 0.12);
  border-color: var(--dumai-teal);
  width: 280px;
}

.utility-search-box svg {
  width: 13px;
  height: 13px;
  stroke: #94a3b8;
  stroke-width: 2;
  fill: none;
  flex-shrink: 0;
}

.utility-search-input {
  background: transparent;
  border: none;
  outline: none;
  color: #ffffff;
  font-size: 11.5px;
  width: 100%;
  font-family: inherit;
}

.utility-search-input::placeholder {
  color: #64748b;
}

/* ══════════════════════════════════════════════
   2. PRIMARY HEADER & NAVIGATION
══════════════════════════════════════════════ */
header.site-header {
  background: #ffffff !important;
  border-bottom: 1px solid var(--dumai-border-subtle) !important;
  position: sticky !important;
  top: 0 !important;
  z-index: 1000 !important;
  box-shadow: 0 2px 12px rgba(15, 36, 69, 0.08) !important;
  transition: box-shadow 0.25s ease, background-color 0.25s ease !important;
  width: 100%;
}

header.site-header.is-pinned {
  box-shadow: 0 4px 20px rgba(15, 36, 69, 0.12) !important;
  border-bottom-color: rgba(15, 36, 69, 0.12) !important;
}

.header-container {
  max-width: 1440px;
  margin: 0 auto;
  padding: 0 clamp(20px, 4vw, 64px);
  height: 76px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 14px;
  text-decoration: none;
  color: var(--dumai-navy-900);
}

.brand-logo img {
  height: 38px;
  width: auto;
  display: block;
}

.brand-logo-text {
  display: flex;
  flex-direction: column;
  line-height: 1.15;
}

.brand-logo-text strong {
  font-size: 16px;
  font-weight: 800;
  letter-spacing: 0.08em;
  color: var(--dumai-navy-900);
  text-transform: uppercase;
  font-family: var(--dumai-font-sans);
}

.brand-logo-text small {
  font-size: 10px;
  letter-spacing: 0.12em;
  color: var(--dumai-text-muted);
  text-transform: uppercase;
  font-weight: 600;
  font-family: var(--dumai-font-sans);
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 36px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-menu li {
  margin: 0;
  padding: 0;
}

.nav-menu a {
  color: var(--dumai-text-primary);
  text-decoration: none;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: -0.01em;
  padding: 26px 0;
  display: inline-block;
  position: relative;
  transition: color 0.15s ease;
  font-family: var(--dumai-font-sans);
}

.nav-menu a:hover {
  color: var(--dumai-blue-primary);
}

.nav-menu a.active {
  color: var(--dumai-navy-850);
}

.nav-menu a.active::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--dumai-navy-850);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}

.header-actions .btn-primary-nav {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--dumai-blue-primary);
  color: #ffffff;
  padding: 12px 24px;
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
  border-radius: 4px;
  border: 1px solid var(--dumai-blue-primary);
  box-shadow: 0 1px 3px rgba(37, 46, 128, 0.2);
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  white-space: nowrap;
  font-family: var(--dumai-font-sans);
}

.header-actions .btn-primary-nav:hover {
  background: var(--dumai-blue-hover);
  border-color: var(--dumai-blue-hover);
  box-shadow: 0 4px 12px rgba(37, 46, 128, 0.25);
  transform: translateY(-1px);
}

.header-actions .btn-primary-nav svg {
  width: 14px;
  height: 14px;
  stroke: currentColor;
  stroke-width: 2.5;
  fill: none;
  transition: transform 0.2s;
}

.header-actions .btn-primary-nav:hover svg {
  transform: translate(2px, -2px);
}

/* Hamburger Menu Button */
.mobile-menu-btn {
  display: none;
  width: 42px;
  height: 42px;
  flex-shrink: 0;
  background: transparent;
  border: 1.5px solid var(--dumai-border-subtle);
  border-radius: 4px;
  cursor: pointer;
  padding: 11px 9px;
  flex-direction: column;
  justify-content: space-between;
  align-items: center;
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}

.mobile-menu-btn:hover {
  background: #f1f5f9;
  border-color: #cbd5e1;
}

.hamburger-bar {
  width: 22px;
  height: 2px;
  background: var(--dumai-navy-850);
  border-radius: 2px;
  transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.2s;
}

.mobile-menu-btn.is-active .hamburger-bar:nth-child(1) {
  transform: translateY(8px) rotate(45deg);
}

.mobile-menu-btn.is-active .hamburger-bar:nth-child(2) {
  opacity: 0;
}

.mobile-menu-btn.is-active .hamburger-bar:nth-child(3) {
  transform: translateY(-8px) rotate(-45deg);
}

/* ══════════════════════════════════════════════
   3. UNIVERSAL MOBILE NAVIGATION DRAWER
══════════════════════════════════════════════ */
.mobile-nav-overlay {
  position: fixed;
  inset: 0;
  background: rgba(9, 22, 41, 0.65);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  z-index: 2000;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s cubic-bezier(0.16, 1, 0.3, 1), visibility 0.3s;
}

.mobile-nav-overlay.is-open {
  opacity: 1;
  visibility: visible;
}

.mobile-nav-drawer {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  width: min(380px, 86vw);
  background: #ffffff;
  z-index: 2001;
  display: flex;
  flex-direction: column;
  transform: translateX(100%);
  transition: transform 0.32s cubic-bezier(0.16, 1, 0.3, 1);
  box-shadow: -10px 0 36px rgba(9, 22, 41, 0.22);
  overflow-y: auto;
}

.mobile-nav-drawer.is-open {
  transform: translateX(0);
}

.mobile-drawer-header {
  padding: 20px 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--dumai-border-subtle);
  background: #ffffff;
  position: sticky;
  top: 0;
  z-index: 2;
}

.mobile-drawer-close {
  width: 36px;
  height: 36px;
  border-radius: 4px;
  border: 1px solid var(--dumai-border-subtle);
  background: #f8fafc;
  color: var(--dumai-navy-850);
  font-size: 22px;
  line-height: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.2s;
}

.mobile-drawer-close:hover {
  background: #e2e8f0;
  border-color: #cbd5e1;
}

.mobile-drawer-search {
  padding: 16px 24px;
  background: #f8fafc;
  border-bottom: 1px solid #e2e8f0;
}

.mobile-drawer-menu {
  list-style: none;
  padding: 8px 0;
  flex: 1;
  margin: 0;
}

.mobile-drawer-menu li a {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px 24px;
  font-size: 15.5px;
  font-weight: 700;
  color: var(--dumai-navy-900);
  text-decoration: none;
  border-bottom: 1px solid #f1f5f9;
  transition: all 0.15s ease;
}

.mobile-drawer-menu li a:hover,
.mobile-drawer-menu li a.active {
  background: #f1f5f9;
  color: var(--dumai-blue-primary);
  padding-left: 28px;
}

.mobile-drawer-menu li a svg {
  width: 16px;
  height: 16px;
  color: #94a3b8;
}

.mobile-drawer-footer {
  padding: 24px;
  border-top: 1px solid var(--dumai-border-subtle);
  background: #f8fafc;
}

/* ══════════════════════════════════════════════
   4. UNIVERSAL SITE FOOTER
══════════════════════════════════════════════ */
footer.site-footer {
  background: var(--dumai-navy-900);
  color: #94a3b8;
  padding: 64px 0 32px;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  width: 100%;
}

/* ══════════════════════════════════════════════
   5. BACK TO TOP
══════════════════════════════════════════════ */
.back-to-top {
  position: fixed;
  right: clamp(16px, 3vw, 40px);
  bottom: 24px;
  z-index: 950;
  display: flex;
  width: 52px;
  height: 52px;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1px;
  padding: 0;
  border: 1px solid rgba(15, 36, 69, 0.14);
  border-radius: 50%;
  background: #ffffff;
  color: var(--dumai-blue-primary);
  box-shadow: 0 8px 24px rgba(13, 22, 39, 0.28);
  cursor: pointer;
  font: inherit;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transform: translateY(8px);
  transition: opacity 0.2s ease, visibility 0.2s ease, transform 0.2s ease, background-color 0.2s ease;
}

.back-to-top.is-visible {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transform: translateY(0);
}

.back-to-top:hover {
  background: #f1f5f9;
  transform: translateY(-2px);
}

.back-to-top:focus-visible {
  outline: 3px solid var(--dumai-teal);
  outline-offset: 3px;
}

.back-to-top svg {
  width: 16px;
  height: 16px;
  fill: none;
  stroke: currentColor;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-width: 2;
}

.back-to-top span {
  font-size: 9px;
  font-weight: 800;
  letter-spacing: 0.08em;
  line-height: 1;
}

.site-footer .container-bounded {
  max-width: 1440px;
  margin: 0 auto;
  padding: 0 clamp(20px, 4vw, 64px);
}

.footer-clean-top {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 48px;
  margin-bottom: 48px;
  flex-wrap: wrap;
}

.footer-left {
  max-width: 440px;
}

.footer-left-title {
  color: #ffffff;
  font-size: 16px;
  font-weight: 800;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  margin-bottom: 12px;
}

.footer-left-desc {
  font-size: 13.5px;
  line-height: 1.6;
  color: #64748b;
  margin-bottom: 24px;
}

.footer-social-row {
  display: flex;
  align-items: center;
  gap: 12px;
}

.social-icon-btn {
  width: 40px;
  height: 40px;
  border-radius: 4px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.1);
  color: #cbd5e1;
  display: flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}

.social-icon-btn:hover {
  background: var(--dumai-teal);
  border-color: var(--dumai-teal);
  color: #091322;
  transform: translateY(-2px);
}

.social-icon-btn svg {
  width: 18px;
  height: 18px;
  fill: currentColor;
}

.footer-right-cols {
  display: flex;
  gap: clamp(32px, 5vw, 64px);
  flex-wrap: wrap;
}

.footer-col-simple {
  min-width: 140px;
}

.footer-col-simple h5 {
  font-size: 11px;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: #ffffff;
  margin: 0 0 16px 0;
}

.footer-col-simple ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin: 0;
  padding: 0;
}

.footer-col-simple a {
  color: #94a3b8;
  text-decoration: none;
  font-size: 13.5px;
  transition: color 0.15s ease;
}

.footer-col-simple a:hover {
  color: #ffffff;
}

.footer-bottom {
  padding-top: 28px;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 12px;
  color: #64748b;
  flex-wrap: wrap;
  gap: 16px;
}

/* ══════════════════════════════════════════════
   6. RESPONSIVE BREAKPOINTS (Header & Footer)
══════════════════════════════════════════════ */
@media (max-width: 1024px) {
  .nav-menu { display: none !important; }
  .mobile-menu-btn { display: flex !important; }
  .header-actions .btn-primary-nav {
    padding: 10px 18px;
    font-size: 13px;
  }
  .footer-clean-top { gap: 36px; }
  .footer-right-cols { gap: 36px; }
}

@media (max-width: 768px) {
  .top-utility { height: 34px; font-size: 11px; }
  .utility-search-box { display: none !important; }
  .utility-container { justify-content: center !important; }
  .header-container { height: 64px !important; }
  .brand-logo img { height: 32px !important; }
  .brand-logo-text strong { font-size: 15px !important; }
  .brand-logo-text small { font-size: 9px !important; }
  .header-actions .btn-primary-nav { display: none !important; }
  .mobile-menu-btn { display: flex !important; }

  .footer-clean-top {
    flex-direction: column;
    gap: 36px;
  }
  .footer-left { max-width: 100%; }
  .footer-right-cols {
    flex-direction: column;
    gap: 28px;
    width: 100%;
  }
  .footer-col-simple { width: 100%; }
  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
  }
}

@media (max-width: 480px) {
  .header-actions .btn-primary-nav {
    display: none !important;
  }
}