/* ==========================================================================
   HRI ENTEC - Premium Standalone Static Design System
   Company: HRI ENTEC CO., LTD.
   Technology: Pure Vanilla CSS3 (Zero external dependencies)
   ========================================================================== */

:root {
  /* Color Palette */
  --bg-dark: #040421;
  --bg-dark-secondary: #080833;
  --bg-dark-tertiary: #0e0e47;
  --bg-surface: #0a0a38;
  --bg-tile-dark: #050529;
  --bg-tile-blue: #1c4b82;
  --bg-tile-red: #ba1414;
  
  --text-main: #ffffff;
  --text-muted: #b8b8d0;
  --text-subtle: #8585a8;
  
  --accent-red: #e51d1d;
  --accent-red-hover: #ff3333;
  --accent-yellow: #f8c01c;
  --accent-yellow-light: #ffdc52;
  --accent-blue: #2563eb;
  
  --border-subtle: rgba(255, 255, 255, 0.08);
  --border-light: rgba(255, 255, 255, 0.15);
  
  /* Typography */
  --font-heading: 'Barlow', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  
  /* Transitions & Shadows */
  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  --shadow-card: 0 10px 30px rgba(0, 0, 0, 0.4);
  --shadow-glow: 0 0 25px rgba(248, 192, 28, 0.25);
  
  /* Layout Sizing */
  --header-height: 80px;
  --max-width: 1280px;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  background-color: var(--bg-dark);
  color: var(--text-main);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-body);
  line-height: 1.6;
  background-color: var(--bg-dark);
  color: var(--text-main);
  overflow-x: hidden;
  position: relative;
}

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

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

ul {
  list-style: none;
}

/* ==========================================================================
   Header & Sticky Navigation (Clean White Bar matching original site)
   ========================================================================== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--header-height);
  z-index: 1000;
  background-color: rgba(255, 255, 255, 0.98);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(0, 0, 0, 0.08);
  box-shadow: 0 2px 15px rgba(0, 0, 0, 0.06);
  transition: all var(--transition-normal);
}

.site-header.scrolled {
  height: 68px;
  background-color: #ffffff;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.12);
}

.nav-container {
  max-width: 1440px;
  height: 100%;
  margin: 0 auto;
  padding: 0 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-brand {
  display: flex;
  align-items: center;
  height: 100%;
}

.brand-logo {
  height: 50px;
  width: auto;
  object-fit: contain;
  transition: transform var(--transition-fast);
}

.site-header.scrolled .brand-logo {
  height: 44px;
}

.brand-logo:hover {
  transform: scale(1.03);
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 2rem;
}

.nav-item {
  position: relative;
}

.nav-link {
  font-family: var(--font-heading);
  font-size: 1.05rem;
  font-weight: 500;
  letter-spacing: 0.5px;
  color: #333344;
  padding: 0.5rem 0;
  display: flex;
  align-items: center;
  gap: 0.4rem;
  transition: color var(--transition-fast);
}

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

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

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

.nav-link-map {
  display: inline-flex;
  align-items: center;
  padding: 0.4rem;
  border-radius: 50%;
  background: rgba(0, 0, 0, 0.05);
  transition: all var(--transition-fast);
}

.nav-link-map:hover {
  background: rgba(0, 0, 0, 0.12);
  transform: scale(1.1);
}

.nav-link-map img {
  width: 20px;
  height: 20px;
}

/* Mobile Menu Toggle */
.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
  color: #222233;
  flex-direction: column;
  gap: 5px;
}

.mobile-menu-btn span {
  display: block;
  width: 24px;
  height: 2px;
  background-color: #222233;
  transition: transform var(--transition-fast), opacity var(--transition-fast);
}

/* ==========================================================================
   Hero Section with Dynamic Multi-Image Background Slideshow
   ========================================================================== */
.hero-section {
  position: relative;
  min-height: 100vh;
  padding-top: var(--header-height);
  display: flex;
  align-items: center;
  justify-content: flex-start;
  overflow: hidden;
  background-color: #040421;
}

.hero-slideshow {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  z-index: 1;
}

.hero-slide {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  background-position: center;
  background-size: cover;
  background-repeat: no-repeat;
  opacity: 0;
  transform: scale(1.05);
  transition: opacity 1.4s cubic-bezier(0.4, 0, 0.2, 1), transform 6s ease-out;
  will-change: opacity, transform;
}

.hero-slide.active {
  opacity: 1;
  transform: scale(1.0);
  z-index: 2;
}

.hero-overlay {
  position: absolute;
  inset: 0;
  z-index: 3;
  background: linear-gradient(
    135deg,
    rgba(4, 4, 33, 0.6) 0%,
    rgba(4, 4, 33, 0.3) 50%,
    rgba(4, 4, 33, 0.85) 100%
  );
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 4;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 4rem 2rem;
  width: 100%;
}

.hero-title {
  font-family: var(--font-heading);
  font-size: clamp(2.5rem, 6vw, 5rem);
  font-weight: 700;
  line-height: 1.1;
  text-transform: uppercase;
  margin-bottom: 1rem;
  letter-spacing: 1px;
  text-shadow: 0 4px 15px rgba(0, 0, 0, 0.8);
}

.hero-title .highlight-red {
  color: var(--accent-red);
}

.hero-title .highlight-yellow {
  color: var(--accent-yellow);
}

.hero-subtitle {
  font-family: var(--font-heading);
  font-size: clamp(1.2rem, 3vw, 2.2rem);
  font-weight: 600;
  color: var(--accent-yellow);
  text-transform: uppercase;
  letter-spacing: 2px;
  margin-bottom: 2rem;
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.8);
}

.hero-cta {
  display: flex;
  gap: 1.25rem;
  flex-wrap: wrap;
}

/* Slideshow Navigation Indicators */
.hero-slide-indicators {
  position: absolute;
  bottom: 2.5rem;
  left: 50%;
  transform: translateX(-50%);
  z-index: 5;
  display: flex;
  gap: 0.85rem;
}

.slide-indicator {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  border: 2px solid rgba(255, 255, 255, 0.6);
  background: transparent;
  cursor: pointer;
  transition: all var(--transition-fast);
  padding: 0;
}

.slide-indicator:hover {
  border-color: #ffffff;
  transform: scale(1.2);
}

.slide-indicator.active {
  border-color: var(--accent-yellow);
  background-color: var(--accent-yellow);
  box-shadow: 0 0 12px rgba(248, 192, 28, 0.7);
  transform: scale(1.25);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-heading);
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: 0.5px;
  padding: 0.85rem 2rem;
  border-radius: 4px;
  transition: all var(--transition-fast);
  cursor: pointer;
  text-transform: uppercase;
}

.btn-primary {
  background-color: var(--accent-red);
  color: #ffffff;
  border: 1px solid var(--accent-red);
  box-shadow: 0 4px 15px rgba(229, 29, 29, 0.4);
}

.btn-primary:hover {
  background-color: var(--accent-red-hover);
  border-color: var(--accent-red-hover);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(229, 29, 29, 0.6);
}

.btn-outline {
  background-color: transparent;
  color: #ffffff;
  border: 1px solid rgba(255, 255, 255, 0.5);
}

.btn-outline:hover {
  background-color: rgba(255, 255, 255, 0.15);
  border-color: #ffffff;
  transform: translateY(-2px);
}

/* ==========================================================================
   About Us Section
   ========================================================================== */
.about-section {
  padding: 6rem 2rem;
  background-color: var(--bg-dark);
  position: relative;
  border-bottom: 1px solid var(--border-subtle);
}

.about-container {
  max-width: var(--max-width);
  margin: 0 auto;
  text-align: center;
}

.section-title {
  font-family: var(--font-heading);
  font-size: clamp(2.2rem, 4.5vw, 3.5rem);
  font-weight: 600;
  color: var(--text-main);
  letter-spacing: 1px;
  margin-bottom: 0.5rem;
}

.section-subtitle {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 500;
  color: var(--accent-yellow);
  text-transform: uppercase;
  letter-spacing: 1.5px;
  margin-bottom: 1.5rem;
}

.mission-box {
  max-width: 860px;
  margin: 0 auto 3.5rem;
  padding: 1.5rem 2rem;
  background: rgba(255, 255, 255, 0.02);
  border-radius: 8px;
  border: 1px solid var(--border-subtle);
}

.mission-text {
  font-size: clamp(1.05rem, 2vw, 1.35rem);
  font-weight: 300;
  line-height: 1.8;
  color: #e2e2f0;
  font-style: italic;
}

.about-photo-wrapper {
  max-width: 1040px;
  margin: 0 auto;
  border-radius: 6px;
  overflow: hidden;
  box-shadow: var(--shadow-card);
  border: 1px solid var(--border-light);
  transition: transform var(--transition-normal);
}

.about-photo-wrapper:hover {
  transform: translateY(-4px);
}

.about-photo {
  width: 100%;
  height: auto;
  object-fit: cover;
}

/* ==========================================================================
   Services Section & Mosaic Grid
   ========================================================================== */
.services-section {
  background-color: var(--bg-dark);
  position: relative;
}

.services-hero-banner {
  padding: 5rem 2rem 4rem;
  text-align: center;
  background: linear-gradient(rgba(4, 4, 33, 0.85), rgba(4, 4, 33, 0.95)),
              url('../assets/images/hero/hero-slide-1.jpg') center/cover no-repeat;
  border-bottom: 1px solid var(--border-subtle);
}

.services-intro-text {
  max-width: 900px;
  margin: 1.5rem auto 0;
  font-size: 1.15rem;
  line-height: 1.8;
  color: var(--text-muted);
}

/* Mosaic Grid (4 Columns x 4 Rows = 16 Tiles) */
.mosaic-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  width: 100%;
}

.mosaic-tile {
  position: relative;
  min-height: 340px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 2.5rem 2rem;
  overflow: hidden;
  transition: all var(--transition-fast);
}

/* Tile Types */
.tile-dark {
  background-color: var(--bg-tile-dark);
  color: var(--text-main);
  border: 1px solid rgba(255, 255, 255, 0.04);
}

.tile-red {
  background-color: var(--bg-tile-red);
  color: #ffffff;
}

.tile-blue {
  background-color: var(--bg-tile-blue);
  color: #ffffff;
}

.tile-image {
  padding: 0;
  background-color: #000000;
}

.tile-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.mosaic-tile.tile-image:hover img {
  transform: scale(1.08);
}

/* Tile Content */
.tile-title {
  font-family: var(--font-heading);
  font-size: 1.35rem;
  font-weight: 700;
  letter-spacing: 1px;
  text-transform: uppercase;
  margin-bottom: 1.25rem;
  line-height: 1.3;
}

.tile-list {
  list-style: none;
}

.tile-list li {
  font-size: 0.95rem;
  line-height: 1.6;
  position: relative;
  padding-left: 1.2rem;
  margin-bottom: 0.5rem;
  color: rgba(255, 255, 255, 0.92);
}

.tile-list li::before {
  content: '•';
  position: absolute;
  left: 0;
  color: var(--accent-yellow);
  font-size: 1.1rem;
}

.tile-red .tile-list li::before {
  color: #ffffff;
}

/* ==========================================================================
   Certifications & ASME Stamps Section
   ========================================================================== */
.stamps-section {
  padding: 5rem 2rem;
  background-color: var(--bg-dark);
  text-align: center;
  border-bottom: 1px solid var(--border-subtle);
}

.stamps-container {
  max-width: var(--max-width);
  margin: 0 auto;
}

.stamps-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 2.5rem;
  flex-wrap: wrap;
  margin-bottom: 2.5rem;
}

.stamp-badge {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1rem;
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.2);
  transition: all var(--transition-normal);
}

.stamp-badge:hover {
  transform: translateY(-5px);
  background: rgba(255, 255, 255, 0.12);
  border-color: var(--accent-yellow);
  box-shadow: var(--shadow-glow);
}

.stamp-badge img {
  height: 75px;
  width: auto;
  object-fit: contain;
  filter: drop-shadow(0 4px 6px rgba(0, 0, 0, 0.5));
}

.stamps-heading {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--text-main);
  margin-bottom: 0.75rem;
  letter-spacing: 0.5px;
}

.stamps-subtext {
  max-width: 800px;
  margin: 0 auto;
  font-size: 1.05rem;
  line-height: 1.7;
  color: var(--text-muted);
}

/* ==========================================================================
   Clients Section
   ========================================================================== */
.clients-section {
  padding: 6rem 2rem;
  background-color: var(--bg-dark);
  border-bottom: 1px solid var(--border-subtle);
}

.clients-container {
  max-width: var(--max-width);
  margin: 0 auto;
  text-align: center;
}

.clients-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
  margin-top: 3.5rem;
}

.client-card {
  background: #ffffff;
  border-radius: 6px;
  padding: 1.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 120px;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
  transition: all var(--transition-normal);
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.client-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.5);
}

.client-card img {
  max-height: 65px;
  width: auto;
  max-width: 90%;
  object-fit: contain;
}

/* ==========================================================================
   Contact Us Section
   ========================================================================== */
.contact-section {
  padding: 6rem 2rem 4rem;
  background-color: var(--bg-dark);
}

.contact-container {
  max-width: var(--max-width);
  margin: 0 auto;
}

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3.5rem;
  align-items: stretch;
  margin-bottom: 5rem;
}

.map-wrapper {
  border-radius: 8px;
  overflow: hidden;
  box-shadow: var(--shadow-card);
  border: 1px solid var(--border-light);
  min-height: 380px;
  background-color: var(--bg-surface);
  position: relative;
}

.map-iframe {
  width: 100%;
  height: 100%;
  min-height: 380px;
  border: 0;
}

.contact-info-card {
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.contact-title {
  font-family: var(--font-heading);
  font-size: clamp(2rem, 3.5vw, 2.75rem);
  font-weight: 700;
  margin-bottom: 1rem;
}

.contact-company {
  font-family: var(--font-heading);
  font-size: 1.35rem;
  font-weight: 600;
  color: var(--accent-yellow);
  margin-bottom: 1.5rem;
  letter-spacing: 0.5px;
}

.contact-detail-item {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  margin-bottom: 1.25rem;
  font-size: 1.05rem;
  color: var(--text-muted);
}

.contact-detail-item strong {
  color: var(--text-main);
  min-width: 85px;
}

.contact-detail-item a {
  color: #60a5fa;
  transition: color var(--transition-fast);
}

.contact-detail-item a:hover {
  color: #93c5fd;
  text-decoration: underline;
}

.contact-actions {
  display: flex;
  gap: 1rem;
  margin-top: 2rem;
  flex-wrap: wrap;
}

/* Factory Showcase Video Banner */
.factory-showcase {
  max-width: var(--max-width);
  margin: 0 auto;
  border-radius: 8px;
  overflow: hidden;
  box-shadow: var(--shadow-card);
  border: 1px solid var(--border-light);
  position: relative;
  background-color: #000000;
}

.factory-video {
  width: 100%;
  height: auto;
  display: block;
  object-fit: cover;
}

.factory-badge {
  position: absolute;
  bottom: 1.5rem;
  left: 50%;
  transform: translateX(-50%);
  background: rgba(4, 4, 33, 0.85);
  backdrop-filter: blur(8px);
  padding: 0.75rem 2rem;
  border-radius: 4px;
  border: 1px solid var(--border-light);
  font-family: var(--font-heading);
  font-size: clamp(1rem, 2vw, 1.4rem);
  font-weight: 700;
  color: #ffffff;
  letter-spacing: 1px;
  text-transform: uppercase;
  white-space: nowrap;
  pointer-events: none;
}

/* ==========================================================================
   Footer
   ========================================================================== */
.site-footer {
  padding: 2.5rem 2rem;
  background-color: #020214;
  border-top: 1px solid var(--border-subtle);
  text-align: center;
}

.footer-copy {
  font-size: 0.95rem;
  color: var(--text-subtle);
}

/* ==========================================================================
   Vertical Dot Navigation Indicator (Right Sidebar)
   ========================================================================== */
.vertical-dots-nav {
  position: fixed;
  right: 2rem;
  top: 50%;
  transform: translateY(-50%);
  z-index: 999;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.dot-nav-item {
  position: relative;
}

.dot-nav-link {
  display: block;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  border: 2px solid rgba(255, 255, 255, 0.45);
  background: transparent;
  transition: all var(--transition-fast);
}

.dot-nav-link:hover {
  border-color: #ffffff;
  transform: scale(1.3);
}

.dot-nav-link.active {
  border-color: var(--accent-yellow);
  background-color: var(--accent-yellow);
  box-shadow: 0 0 10px rgba(248, 192, 28, 0.6);
  transform: scale(1.2);
}

.dot-tooltip {
  position: absolute;
  right: 20px;
  top: 50%;
  transform: translateY(-50%);
  background: rgba(4, 4, 33, 0.9);
  color: #ffffff;
  padding: 0.25rem 0.6rem;
  border-radius: 4px;
  font-size: 0.75rem;
  font-family: var(--font-heading);
  white-space: nowrap;
  pointer-events: none;
  opacity: 0;
  transition: opacity var(--transition-fast);
  border: 1px solid var(--border-subtle);
}

.dot-nav-item:hover .dot-tooltip {
  opacity: 1;
}

/* ==========================================================================
   Responsive Media Queries
   ========================================================================== */
@media (max-width: 1024px) {
  .mosaic-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .clients-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .contact-grid {
    grid-template-columns: 1fr;
    gap: 2.5rem;
  }
}

@media (max-width: 768px) {
  :root {
    --header-height: 70px;
  }
  
  .vertical-dots-nav {
    display: none;
  }
  
  .mobile-menu-btn {
    display: flex;
  }
  
  .nav-menu {
    position: fixed;
    top: var(--header-height);
    left: 0;
    width: 100%;
    height: calc(100vh - var(--header-height));
    background-color: #ffffff;
    flex-direction: column;
    align-items: center;
    justify-content: flex-start;
    padding: 3rem 2rem;
    gap: 1.75rem;
    transform: translateX(100%);
    transition: transform var(--transition-normal);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
  }
  
  .nav-menu.open {
    transform: translateX(0);
  }
  
  .nav-link {
    font-size: 1.35rem;
    color: #111122;
  }
  
  .mosaic-grid {
    grid-template-columns: 1fr;
  }

  /* Consistent Mobile Pairing: Every service displays Image -> Text */
  .mosaic-grid > :nth-child(1)  { order: 1; }  /* HRSG Image */
  .mosaic-grid > :nth-child(2)  { order: 2; }  /* HRSG Text */
  .mosaic-grid > :nth-child(3)  { order: 3; }  /* Waste Heat Image */
  .mosaic-grid > :nth-child(4)  { order: 4; }  /* Waste Heat Text */
  .mosaic-grid > :nth-child(5)  { order: 6; }  /* Diverter Damper Text */
  .mosaic-grid > :nth-child(6)  { order: 5; }  /* Diverter Damper Image */
  .mosaic-grid > :nth-child(7)  { order: 8; }  /* Expansion Joints Text */
  .mosaic-grid > :nth-child(8)  { order: 7; }  /* Expansion Joints Image */
  .mosaic-grid > :nth-child(9)  { order: 9; }  /* Heat Exchangers Image */
  .mosaic-grid > :nth-child(10) { order: 10; } /* Heat Exchangers Text */
  .mosaic-grid > :nth-child(11) { order: 11; } /* Vessel & Reactor Image */
  .mosaic-grid > :nth-child(12) { order: 12; } /* Vessel & Reactor Text */
  .mosaic-grid > :nth-child(13) { order: 14; } /* Turnkey Project Text */
  .mosaic-grid > :nth-child(14) { order: 13; } /* Turnkey Project Image */
  .mosaic-grid > :nth-child(15) { order: 16; } /* Maintenance Text */
  .mosaic-grid > :nth-child(16) { order: 15; } /* Maintenance Image */

  .mosaic-tile {
    min-height: auto;
    padding: 2.25rem 1.5rem;
  }

  .mosaic-tile.tile-image {
    min-height: 260px;
  }
  
  .clients-grid {
    grid-template-columns: 1fr;
    gap: 1.25rem;
  }
  
  .stamps-row {
    gap: 1.25rem;
  }
  
  .stamp-badge img {
    height: 52px;
  }

  .hero-slide-indicators {
    bottom: 1.5rem;
  }

  .factory-badge {
    font-size: 0.85rem;
    padding: 0.5rem 1rem;
    bottom: 0.75rem;
    max-width: 90%;
    white-space: normal;
    text-align: center;
    letter-spacing: 0.5px;
    line-height: 1.3;
  }
}