/* ==========================================================================
   Guangdong Black Hole Ceramics Technology Co., Ltd.
   B2B Foreign Trade Inquiry & Exhibition Design System
   ========================================================================== */

:root {
  /* Color Tokens */
  --color-primary: #181818;
  --color-primary-light: #282828;
  --color-accent: #C5A059;
  --color-accent-hover: #b08d48;
  --color-dark-green: #112523;
  --color-bg: #FFFFFF;
  --color-bg-alt: #F9F8F6;
  --color-bg-subtle: #F2F0EC;
  --color-border: #E5E2DC;
  --color-border-subtle: #EBE8E3;
  --color-text: #2C2C2C;
  --color-text-muted: #6C6965;
  --color-white: #FFFFFF;
  
  /* Layout & Geometry */
  --container-max: 1440px;
  --header-height: 84px;
  --announcement-height: 38px;
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-pill: 9999px;
  
  /* Transitions */
  --transition-fast: 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-smooth: 0.35s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-slow: 0.6s cubic-bezier(0.16, 1, 0.3, 1);
  
  /* Shadows */
  --shadow-subtle: 0 4px 20px rgba(0, 0, 0, 0.04);
  --shadow-hover: 0 12px 36px rgba(0, 0, 0, 0.08);
  --shadow-drawer: -8px 0 32px rgba(0, 0, 0, 0.15);
}

/* Reset & Base */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  background-color: var(--color-bg);
  color: var(--color-text);
  overflow-x: hidden;
  position: relative;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

button, input, textarea, select {
  font-family: inherit;
}

button {
  cursor: pointer;
  border: none;
  background: none;
}

.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: clamp(1rem, 3vw, 2.5rem);
  padding-right: clamp(1rem, 3vw, 2.5rem);
}

/* ==========================================================================
   Announcement Bar (Top B2B Contact & Ticker)
   ========================================================================== */
.announcement-bar {
  background-color: var(--color-primary);
  color: var(--color-white);
  height: var(--announcement-height);
  display: flex;
  align-items: center;
  overflow: hidden;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.announcement-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 100%;
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.06em;
}

.b2b-contact-link {
  color: var(--color-accent);
  font-weight: 700;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}

/* ==========================================================================
   Main Header & Navigation
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: rgba(255, 255, 255, 0.96);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border-subtle);
  transition: all var(--transition-fast);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-height);
}

.brand-logo {
  display: flex;
  flex-direction: column;
  text-align: left;
  line-height: 1;
}

.logo-text {
  font-family: var(--font-serif);
  font-size: 1.6rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--color-primary);
  text-transform: uppercase;
}

.logo-tagline {
  font-family: var(--font-sans);
  font-size: 0.55rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-top: 3px;
  font-weight: 700;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 2.25rem;
  list-style: none;
}

.nav-item {
  position: relative;
}

.nav-link {
  font-size: 0.8125rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--color-primary);
  padding: 1.5rem 0;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  position: relative;
}

.nav-link.active,
.nav-link:hover {
  color: var(--color-accent);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 1.25rem;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--color-accent);
  transition: width var(--transition-fast);
}

.nav-link.active::after,
.nav-item:hover .nav-link::after {
  width: 100%;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.action-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  color: var(--color-primary);
  transition: all var(--transition-fast);
  position: relative;
}

.action-btn:hover {
  background-color: var(--color-bg-subtle);
}

.badge-count {
  position: absolute;
  top: 4px;
  right: 4px;
  background-color: var(--color-accent);
  color: var(--color-white);
  font-size: 0.625rem;
  font-weight: 700;
  width: 17px;
  height: 17px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* Button System */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.85rem 1.75rem;
  border-radius: var(--radius-md);
  font-size: 0.8125rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  transition: all var(--transition-fast);
  cursor: pointer;
}

.btn-primary {
  background-color: var(--color-primary);
  color: var(--color-white);
}

.btn-primary:hover {
  background-color: var(--color-accent);
  color: var(--color-white);
  transform: translateY(-2px);
  box-shadow: 0 4px 14px rgba(0,0,0,0.15);
}

.btn-accent {
  background-color: var(--color-accent);
  color: var(--color-white);
}

.btn-accent:hover {
  background-color: var(--color-accent-hover);
  transform: translateY(-2px);
}

.btn-outline {
  border: 1.5px solid var(--color-primary);
  color: var(--color-primary);
  background-color: transparent;
}

.btn-outline:hover {
  background-color: var(--color-primary);
  color: var(--color-white);
}

/* ==========================================================================
   Hero Section
   ========================================================================== */
.hero-section {
  position: relative;
  min-height: 80vh;
  display: flex;
  align-items: center;
  background-color: #121212;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 1;
}

.hero-bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: brightness(0.8);
}

.hero-overlay {
  position: absolute;
  inset: 0;
  z-index: 2;
  background: linear-gradient(90deg, rgba(24,24,24,0.85) 0%, rgba(24,24,24,0.4) 60%, transparent 100%);
}

.hero-content {
  position: relative;
  z-index: 3;
  max-width: 720px;
  color: var(--color-white);
  padding: 4rem 0;
}

.hero-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  color: var(--color-accent);
  margin-bottom: 1.25rem;
}

.hero-title {
  font-size: var(--fs-hero);
  color: var(--color-white);
  margin-bottom: 1.5rem;
  line-height: 1.1;
}

.hero-desc {
  font-size: 1.0625rem;
  line-height: 1.6;
  color: #E2DFD9;
  margin-bottom: 2.25rem;
}

.hero-buttons {
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
}

/* ==========================================================================
   Category Discovery & Section Standards
   ========================================================================== */
.section {
  padding: clamp(3.5rem, 6vw, 5.5rem) 0;
}

.section-header {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 3rem auto;
}

.section-subtitle {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.18em;
  color: var(--color-accent);
  margin-bottom: 0.75rem;
}

.section-title {
  font-size: var(--fs-h2);
  margin-bottom: 1rem;
}

.section-desc {
  font-size: 0.9375rem;
  color: var(--color-text-muted);
  line-height: 1.6;
}

.category-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
}

.category-card {
  position: relative;
  border-radius: var(--radius-md);
  overflow: hidden;
  background-color: var(--color-bg-subtle);
  aspect-ratio: 4 / 5;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  padding: 1.5rem;
  box-shadow: var(--shadow-subtle);
  transition: all var(--transition-smooth);
}

.category-card-img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition-slow);
}

.category-card:hover .category-card-img {
  transform: scale(1.08);
}

.category-card-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(to top, rgba(24, 24, 24, 0.85) 0%, rgba(24, 24, 24, 0.2) 50%, transparent 100%);
}

.category-card-content {
  position: relative;
  z-index: 2;
  color: var(--color-white);
}

.category-card-title {
  font-family: var(--font-serif);
  font-size: 1.35rem;
  color: var(--color-white);
  margin-bottom: 0.35rem;
}

.category-card-link {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--color-accent);
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}

/* ==========================================================================
   Product Grid & Catalog Styling
   ========================================================================== */
.products-section {
  background-color: var(--color-bg-alt);
  border-top: 1px solid var(--color-border-subtle);
  border-bottom: 1px solid var(--color-border-subtle);
}

.products-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.75rem;
}

.product-card {
  background-color: var(--color-white);
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border-subtle);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: all var(--transition-smooth);
  position: relative;
}

.product-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-hover);
  border-color: var(--color-border);
}

.product-media {
  position: relative;
  aspect-ratio: 1 / 1;
  background-color: var(--color-bg-subtle);
  overflow: hidden;
}

.product-img-primary,
.product-img-secondary {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: opacity var(--transition-smooth), transform var(--transition-slow);
}

.product-img-secondary {
  opacity: 0;
}

.product-card:hover .product-img-secondary {
  opacity: 1;
  transform: scale(1.05);
}

.product-badge {
  position: absolute;
  top: 12px;
  left: 12px;
  background-color: var(--color-primary);
  color: var(--color-white);
  font-size: 0.625rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  padding: 4px 8px;
  border-radius: var(--radius-sm);
  z-index: 5;
}

.product-body {
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  flex-grow: 1;
}

.product-code {
  font-size: 0.6875rem;
  font-weight: 700;
  color: var(--color-accent);
  letter-spacing: 0.08em;
  margin-bottom: 0.25rem;
}

.product-title {
  font-family: var(--font-serif);
  font-size: 1.2rem;
  color: var(--color-primary);
  margin-bottom: 0.5rem;
}

.product-specs {
  font-size: 0.75rem;
  color: var(--color-text-muted);
  margin-bottom: 1rem;
  line-height: 1.4;
}

.product-b2b-badge {
  background-color: var(--color-bg-subtle);
  padding: 6px 10px;
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--color-primary);
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: auto;
}

.product-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.5rem;
  margin-top: 1rem;
}

/* ==========================================================================
   B2B Inquiry Modal & Forms
   ========================================================================== */
.modal-backdrop {
  position: fixed;
  inset: 0;
  background-color: rgba(0, 0, 0, 0.65);
  backdrop-filter: blur(6px);
  z-index: 3000;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-smooth);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
}

.modal-backdrop.active {
  opacity: 1;
  visibility: visible;
}

.modal-content {
  background-color: var(--color-white);
  border-radius: var(--radius-lg);
  width: 100%;
  max-width: 600px;
  box-shadow: 0 20px 50px rgba(0,0,0,0.3);
  overflow: hidden;
  transform: scale(0.95);
  transition: transform var(--transition-smooth);
}

.modal-backdrop.active .modal-content {
  transform: scale(1);
}

.modal-header {
  background-color: var(--color-primary);
  color: var(--color-white);
  padding: 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.modal-title {
  font-family: var(--font-serif);
  font-size: 1.35rem;
  color: var(--color-white);
}

.modal-close {
  color: var(--color-white);
  font-size: 1.5rem;
  opacity: 0.8;
}

.modal-close:hover {
  opacity: 1;
}

.modal-body {
  padding: 1.75rem;
}

.form-group {
  margin-bottom: 1.25rem;
}

.form-label {
  display: block;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 0.4rem;
  color: var(--color-primary);
}

.form-input, .form-select, .form-textarea {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  background-color: var(--color-bg-alt);
  transition: border-color var(--transition-fast);
}

.form-input:focus, .form-select:focus, .form-textarea:focus {
  outline: none;
  border-color: var(--color-accent);
  background-color: var(--color-white);
}

/* ==========================================================================
   Footer
   ========================================================================== */
.site-footer {
  background-color: var(--color-primary);
  color: #D0CDC3;
  padding: 5rem 0 2rem 0;
  border-top: 1px solid #333;
}

.footer-top {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 3.5rem;
  margin-bottom: 3.5rem;
}

.footer-brand .logo-text {
  color: var(--color-white);
}

.footer-desc {
  font-size: 0.875rem;
  line-height: 1.6;
  margin: 1.25rem 0 1.5rem 0;
  max-width: 380px;
  color: #A8A59E;
}

.footer-contact-item {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  margin-bottom: 0.5rem;
  font-size: 0.875rem;
  color: var(--color-accent);
  font-weight: 600;
}

.footer-column h4 {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--color-white);
  margin-bottom: 1.25rem;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.footer-links a {
  font-size: 0.8125rem;
  color: #A8A59E;
}

.footer-links a:hover {
  color: var(--color-accent);
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.75rem;
  color: #7A7770;
  flex-wrap: wrap;
  gap: 1rem;
}

/* Drawers */
.drawer-backdrop {
  position: fixed;
  inset: 0;
  background-color: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(4px);
  z-index: 2000;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-smooth);
}

.drawer-backdrop.active {
  opacity: 1;
  visibility: visible;
}

.side-drawer {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  width: 100%;
  max-width: 440px;
  background-color: var(--color-white);
  z-index: 2001;
  box-shadow: var(--shadow-drawer);
  transform: translateX(100%);
  transition: transform var(--transition-smooth);
  display: flex;
  flex-direction: column;
}

.side-drawer.active {
  transform: translateX(0);
}

.drawer-header {
  padding: 1.5rem;
  border-bottom: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.drawer-body {
  padding: 1.5rem;
  overflow-y: auto;
  flex: 1;
}

.drawer-footer {
  padding: 1.5rem;
  border-top: 1px solid var(--color-border);
  background-color: var(--color-bg-alt);
}

/* Breakpoints */
@media (max-width: 1200px) {
  .category-grid, .products-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .footer-top {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .nav-menu {
    display: none;
  }
  .category-grid, .products-grid {
    grid-template-columns: 1fr;
  }
  .footer-top {
    grid-template-columns: 1fr;
  }
}