/* ==========================================================================
   Dewill Engineering Limited - Structure Theme Design System
   Core CSS - Yellow (#ffb400), Charcoal (#111111), Light (#f4f4f4)
   ========================================================================== */

:root {
  --primary: #ffb400;
  --primary-hover: #e09e00;
  --dark: #111111;
  --dark-accent: #1e1e1e;
  --secondary: #333333;
  --gray: #666666;
  --light-gray: #f4f4f4;
  --white: #ffffff;
  --border-color: #e2e2e2;
  --font-family: 'Roboto', -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --transition: all 0.35s cubic-bezier(0.165, 0.84, 0.44, 1);
}

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

body {
  font-family: var(--font-family);
  color: var(--secondary);
  background-color: var(--white);
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

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

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

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 15px;
}

/* ==========================================================================
   Header & Top Bar
   ========================================================================== */
.top-bar {
  background: var(--dark);
  color: #bbb;
  font-size: 13px;
  padding: 10px 0;
  border-bottom: 1px solid var(--dark-accent);
}

.top-bar-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
}

.top-contact span {
  margin-right: 20px;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.top-social a {
  color: #bbb;
  margin-left: 12px;
  font-size: 14px;
}

.top-social a:hover {
  color: var(--primary);
}

.site-header {
  background: var(--white);
  box-shadow: 0 2px 10px rgba(0,0,0,0.08);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.header-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 15px 0;
}

.logo-area a {
  display: flex;
  align-items: center;
  gap: 12px;
}

.logo-badge {
  background: var(--primary);
  color: var(--dark);
  font-weight: 900;
  font-size: 22px;
  padding: 8px 14px;
  border-radius: 4px;
  letter-spacing: 1px;
}

.logo-text h1 {
  font-size: 20px;
  font-weight: 800;
  color: var(--dark);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.logo-text p {
  font-size: 11px;
  color: var(--gray);
  letter-spacing: 1px;
  text-transform: uppercase;
}

.main-nav ul {
  display: flex;
  list-style: none;
  gap: 20px;
}

.main-nav a {
  font-size: 13px;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--dark);
  padding: 10px 0;
  position: relative;
}

.main-nav a:hover,
.main-nav a.active {
  color: var(--primary);
}

.main-nav a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 3px;
  background: var(--primary);
  transition: var(--transition);
}

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

.btn-header {
  background: var(--primary);
  color: var(--dark);
  font-weight: 800;
  font-size: 13px;
  padding: 12px 24px;
  text-transform: uppercase;
  border-radius: 4px;
  display: inline-block;
}

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

.mobile-menu-toggle {
  display: none;
  font-size: 24px;
  background: none;
  border: none;
  color: var(--dark);
  cursor: pointer;
}

/* ==========================================================================
   Hero Banners & Sliders
   ========================================================================== */
.hero-slider {
  position: relative;
  background: var(--dark);
  color: var(--white);
  min-height: 520px;
  display: flex;
  align-items: center;
  overflow: hidden;
}

.hero-slide {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  opacity: 0;
  transition: opacity 0.8s ease-in-out;
  display: flex;
  align-items: center;
  background-size: cover;
  background-position: center;
}

.hero-slide.active {
  opacity: 1;
  position: relative;
}

.hero-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(135deg, rgba(17,17,17,0.85) 0%, rgba(17,17,17,0.45) 100%);
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 720px;
}

.hero-subtitle {
  color: var(--primary);
  font-size: 15px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 2px;
  margin-bottom: 15px;
  display: inline-block;
  background: rgba(255, 180, 0, 0.12);
  padding: 6px 14px;
  border-left: 4px solid var(--primary);
}

.hero-title {
  font-size: 40px;
  font-weight: 900;
  line-height: 1.2;
  margin-bottom: 20px;
  text-transform: uppercase;
}

.hero-description {
  font-size: 16px;
  color: #ddd;
  margin-bottom: 30px;
  line-height: 1.6;
}

.btn-primary {
  background: var(--primary);
  color: var(--dark);
  font-weight: 800;
  padding: 14px 32px;
  text-transform: uppercase;
  display: inline-block;
  border-radius: 4px;
  font-size: 14px;
  border: none;
  cursor: pointer;
}

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

.btn-secondary {
  background: transparent;
  color: var(--white);
  border: 2px solid var(--white);
  font-weight: 800;
  padding: 12px 30px;
  text-transform: uppercase;
  display: inline-block;
  border-radius: 4px;
  font-size: 14px;
  margin-left: 15px;
}

.btn-secondary:hover {
  background: var(--white);
  color: var(--dark);
}

/* ==========================================================================
   Section Headers & Cards
   ========================================================================== */
.section {
  padding: 75px 0;
}

.section-bg-light {
  background: var(--light-gray);
}

.section-header {
  text-align: center;
  margin-bottom: 45px;
}

.section-tag {
  color: var(--primary);
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 2px;
  font-size: 13px;
}

.section-title {
  font-size: 32px;
  font-weight: 900;
  color: var(--dark);
  text-transform: uppercase;
  margin-top: 8px;
  position: relative;
  display: inline-block;
}

.section-title::after {
  content: '';
  display: block;
  width: 60px;
  height: 4px;
  background: var(--primary);
  margin: 15px auto 0;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(310px, 1fr));
  gap: 30px;
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 25px;
}

.card {
  background: var(--white);
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 4px 18px rgba(0,0,0,0.06);
  transition: var(--transition);
  border-bottom: 4px solid transparent;
}

.card:hover {
  transform: translateY(-6px);
  border-bottom-color: var(--primary);
  box-shadow: 0 12px 30px rgba(0,0,0,0.12);
}

.card-img {
  height: 230px;
  background-size: cover;
  background-position: center;
  position: relative;
}

.card-badge {
  position: absolute;
  top: 15px;
  left: 15px;
  background: var(--primary);
  color: var(--dark);
  font-size: 11px;
  font-weight: 800;
  padding: 4px 10px;
  text-transform: uppercase;
  border-radius: 3px;
}

.card-body {
  padding: 25px;
}

.card-title {
  font-size: 20px;
  font-weight: 800;
  color: var(--dark);
  margin-bottom: 12px;
}

.card-text {
  font-size: 14px;
  color: var(--gray);
  margin-bottom: 20px;
}

/* ==========================================================================
   Engineering Work Portfolio Grid Styling (Responsive & Native PWA Optimized)
   ========================================================================== */
.portfolio-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 25px;
  margin-top: 20px;
}

.portfolio-item {
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 6px 20px rgba(0,0,0,0.08);
  transition: var(--transition);
  background: var(--dark);
  position: relative;
}

.portfolio-item:hover {
  transform: translateY(-6px);
  box-shadow: 0 15px 35px rgba(0,0,0,0.18);
}

.portfolio-img-box {
  position: relative;
  height: 260px;
  width: 100%;
  overflow: hidden;
}

.portfolio-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
  transition: transform 0.5s ease;
}

.portfolio-item:hover .portfolio-img {
  transform: scale(1.08);
}

.portfolio-overlay {
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  padding: 20px;
  background: linear-gradient(to top, rgba(17,17,17,0.95) 0%, rgba(17,17,17,0.4) 70%, transparent 100%);
  color: var(--white);
  transition: var(--transition);
}

.portfolio-category {
  color: var(--primary);
  font-size: 11px;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  display: block;
  margin-bottom: 5px;
}

.portfolio-title {
  font-size: 17px;
  font-weight: 800;
  margin-bottom: 5px;
  line-height: 1.3;
}

.portfolio-desc {
  font-size: 12px;
  color: #ccc;
  line-height: 1.4;
}

/* ==========================================================================
   Corporate Clients & Developers Grid Styling
   ========================================================================== */
.clients-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 30px;
  margin-top: 20px;
}

.client-card {
  background: var(--white);
  border-radius: 8px;
  padding: 30px 25px;
  box-shadow: 0 4px 20px rgba(0,0,0,0.06);
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  transition: var(--transition);
  border: 1px solid #eaeaea;
  border-top: 4px solid var(--primary);
}

.client-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 12px 30px rgba(0,0,0,0.12);
  border-color: var(--primary);
}

.client-logo-wrapper {
  height: 110px;
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  padding: 10px;
  background: #fafafa;
  border-radius: 6px;
}

.client-logo-img {
  max-height: 90px;
  max-width: 85%;
  object-fit: contain;
  filter: grayscale(15%);
  transition: var(--transition);
}

.client-card:hover .client-logo-img {
  filter: grayscale(0%);
  transform: scale(1.05);
}

.client-name {
  font-size: 18px;
  font-weight: 900;
  color: var(--dark);
  letter-spacing: 0.5px;
  margin-bottom: 8px;
}

.client-desc {
  font-size: 13px;
  color: var(--gray);
  line-height: 1.5;
}

/* ==========================================================================
   Elevator Modules (ERD, Calculator, Warranty)
   ========================================================================== */
.module-box {
  background: var(--dark);
  color: var(--white);
  padding: 35px;
  border-radius: 8px;
  border-left: 6px solid var(--primary);
  margin-bottom: 40px;
}

.module-box h3 {
  color: var(--primary);
  font-size: 24px;
  margin-bottom: 15px;
}

.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  font-size: 13px;
  font-weight: 700;
  text-transform: uppercase;
  margin-bottom: 8px;
}

.form-control {
  width: 100%;
  padding: 12px 16px;
  border: 1px solid var(--border-color);
  border-radius: 4px;
  font-size: 14px;
}

.form-control:focus {
  outline: none;
  border-color: var(--primary);
}

/* ==========================================================================
   Live Chat Floating Widget
   ========================================================================== */
.live-chat-widget {
  position: fixed;
  bottom: 25px;
  right: 25px;
  z-index: 9999;
}

.chat-trigger-btn {
  background: var(--primary);
  color: var(--dark);
  width: 60px;
  height: 60px;
  border-radius: 50%;
  border: none;
  box-shadow: 0 5px 20px rgba(0,0,0,0.25);
  font-size: 26px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
}

.chat-trigger-btn:hover {
  transform: scale(1.1);
}

.chat-box-window {
  position: absolute;
  bottom: 75px;
  right: 0;
  width: 350px;
  height: 460px;
  background: var(--white);
  border-radius: 10px;
  box-shadow: 0 10px 30px rgba(0,0,0,0.2);
  display: none;
  flex-direction: column;
  overflow: hidden;
}

.chat-box-window.active {
  display: flex;
}

.chat-box-header {
  background: var(--dark);
  color: var(--white);
  padding: 15px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.chat-box-messages {
  flex: 1;
  padding: 15px;
  overflow-y: auto;
  background: var(--light-gray);
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.chat-msg {
  max-width: 80%;
  padding: 10px 14px;
  border-radius: 8px;
  font-size: 13px;
}

.chat-msg.visitor {
  background: var(--primary);
  color: var(--dark);
  align-self: flex-end;
}

.chat-msg.admin {
  background: var(--dark);
  color: var(--white);
  align-self: flex-start;
}

.chat-box-footer {
  padding: 10px;
  display: flex;
  gap: 8px;
  border-top: 1px solid var(--border-color);
}

/* ==========================================================================
   Footer
   ========================================================================== */
.site-footer {
  background: var(--dark);
  color: #aaa;
  padding: 70px 0 20px;
  font-size: 14px;
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 40px;
  margin-bottom: 50px;
}

.footer-title {
  color: var(--white);
  font-size: 18px;
  font-weight: 800;
  text-transform: uppercase;
  margin-bottom: 20px;
  border-left: 3px solid var(--primary);
  padding-left: 10px;
}

.footer-links {
  list-style: none;
}

.footer-links li {
  margin-bottom: 10px;
}

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

.footer-bottom {
  border-top: 1px solid var(--dark-accent);
  padding-top: 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  font-size: 13px;
}

/* ==========================================================================
   Responsive & Native PWA App Optimization
   ========================================================================== */
@media (max-width: 991px) {
  .main-nav {
    display: none;
  }
  .mobile-menu-toggle {
    display: block;
  }
  .hero-title {
    font-size: 28px;
  }
  .hero-description {
    font-size: 14px;
  }
  .clients-grid {
    grid-template-columns: 1fr;
  }
  .portfolio-grid {
    grid-template-columns: 1fr;
  }
  .portfolio-item[style*="grid-column"] {
    grid-column: span 1 !important;
  }
}

@media (max-width: 576px) {
  .hero-slider {
    min-height: 440px;
  }
  .btn-primary, .btn-secondary {
    display: block;
    width: 100%;
    margin-left: 0;
    margin-top: 10px;
    text-align: center;
  }
  .top-bar-inner {
    flex-direction: column;
    gap: 8px;
    text-align: center;
  }
  .chat-box-window {
    width: calc(100vw - 30px);
    right: -10px;
  }
}