:root {
  /* Defaults below mirror config.js — that file is the source of truth;
     these exist only as a fallback if config.js fails to load. */
  --color-primary: #00aef0;
  --color-primary-dark: #0089bd;
  --color-accent: #ec008b;
  --color-bg: #fafafa;
  --color-surface: #ffffff;
  --color-text: #241f21;
  --color-text-muted: #5c5658;
  --color-border: #e6e6e6;
  --font-latin: "Inter", system-ui, -apple-system, sans-serif;
  --font-bengali: "Noto Sans Bengali", var(--font-latin);
  --radius: 10px;
  --container-width: 1080px;

  --hero-img-opacity: 0.18;
  --hero-overlay-top: 0.55;
  --hero-overlay-mid: 0.82;
  --hero-overlay-bottom: 0.55;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-bengali), var(--font-latin);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

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

a {
  color: inherit;
  text-decoration: none;
}

h1, h2, h3 {
  font-weight: 700;
  line-height: 1.3;
}

main h2 {
  position: relative;
  padding-bottom: 14px;
}

main h2::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 48px;
  height: 3px;
  background: var(--color-accent);
  border-radius: 2px;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(250, 250, 249, 0.9);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 14px;
  padding-bottom: 14px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.05rem;
}

.brand-logo {
  border-radius: 8px;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 24px;
  font-size: 0.95rem;
}

.site-nav a:hover {
  color: var(--color-primary);
}

.lang-toggle {
  font-family: inherit;
  font-size: 0.85rem;
  font-weight: 600;
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  color: var(--color-text);
  border-radius: 999px;
  padding: 6px 14px;
  cursor: pointer;
  transition: background 0.15s ease, color 0.15s ease;
}

.lang-toggle:hover {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
}

/* Sections */
section {
  padding: 72px 0;
}

.hero {
  position: relative;
  padding-top: 96px;
  padding-bottom: 96px;
  text-align: center;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
}

.hero-bg-img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0;
  animation: heroFade 24s infinite;
}

.hero-bg-img:nth-child(1) { animation-delay: 0s; }
.hero-bg-img:nth-child(2) { animation-delay: 4s; }
.hero-bg-img:nth-child(3) { animation-delay: 8s; }
.hero-bg-img:nth-child(4) { animation-delay: 12s; }
.hero-bg-img:nth-child(5) { animation-delay: 16s; }
.hero-bg-img:nth-child(6) { animation-delay: 20s; }

@keyframes heroFade {
  0%, 100% { opacity: 0; }
  2% { opacity: var(--hero-img-opacity); }
  14% { opacity: var(--hero-img-opacity); }
  16% { opacity: 0; }
}

.hero-overlay {
  position: absolute;
  inset: 0;
  z-index: 0;
  background: linear-gradient(
    180deg,
    rgba(250, 250, 250, var(--hero-overlay-top)) 0%,
    rgba(250, 250, 250, var(--hero-overlay-mid)) 50%,
    rgba(250, 250, 250, var(--hero-overlay-bottom)) 100%
  );
  pointer-events: none;
}

@media (prefers-reduced-motion: reduce) {
  .hero-bg-img {
    animation: none;
  }

  .hero-bg-img:first-child {
    opacity: var(--hero-img-opacity);
  }
}

.hero .container {
  position: relative;
  z-index: 1;
}

.hero h1 {
  font-size: clamp(1.75rem, 4vw, 2.75rem);
  max-width: 780px;
  margin: 0 auto 20px;
}

.hero-sub {
  font-size: 1.1rem;
  color: var(--color-text-muted);
  max-width: 620px;
  margin: 0 auto 36px;
}

.hero-actions {
  display: flex;
  gap: 14px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-block;
  padding: 12px 28px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.95rem;
  transition: transform 0.15s ease, box-shadow 0.15s ease, background 0.15s ease;
}

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

.btn-primary:hover {
  background: var(--color-primary-dark);
  transform: translateY(-1px);
}

.btn-secondary {
  background: var(--color-surface);
  color: var(--color-text);
  border: 1px solid var(--color-border);
}

.btn-secondary:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  transform: translateY(-1px);
}

.about {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
  text-align: center;
}

.about h2 {
  font-size: 1.75rem;
  margin-bottom: 20px;
}

.about p {
  max-width: 680px;
  margin: 0 auto;
  color: var(--color-text-muted);
  font-size: 1.05rem;
}

.features h2 {
  font-size: 1.75rem;
  text-align: center;
  margin-bottom: 44px;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 18px;
}

.feature-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 24px 20px;
  text-align: center;
  transition: box-shadow 0.15s ease, transform 0.15s ease;
}

.feature-card:hover {
  box-shadow: 0 8px 24px rgba(0, 174, 240, 0.15);
  transform: translateY(-2px);
}

.feature-card h3 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-text);
}

.gallery h2 {
  text-align: center;
}

.carousel {
  position: relative;
  margin-top: 32px;
}

.carousel-track {
  display: flex;
  gap: 16px;
  overflow-x: auto;
  padding: 4px 4px 12px;
}

.carousel-track::-webkit-scrollbar {
  height: 6px;
}

.carousel-track::-webkit-scrollbar-thumb {
  background: var(--color-border);
  border-radius: 4px;
}

.carousel-slide {
  flex: 0 0 auto;
  width: 260px;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--color-border);
  background: var(--color-surface);
}

.carousel-slide img {
  width: 100%;
  height: 190px;
  object-fit: cover;
  display: block;
}

.carousel-btn {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  color: var(--color-text);
  font-size: 1.4rem;
  line-height: 1;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 5;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
  transition: background 0.15s ease, color 0.15s ease;
}

.carousel-btn:hover {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
}

.carousel-prev {
  left: -8px;
}

.carousel-next {
  right: -8px;
}

@media (max-width: 640px) {
  .carousel-btn {
    display: none;
  }

  .carousel-slide {
    width: 220px;
  }
}

.trust {
  text-align: center;
  padding: 40px 0;
  color: var(--color-text-muted);
  font-size: 0.95rem;
}

.products h2 {
  font-size: 1.75rem;
  text-align: center;
  margin-bottom: 32px;
}

.product-card {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 28px;
  max-width: 720px;
  margin: 0 auto;
  flex-wrap: wrap;
}

.product-info h3 {
  font-size: 1.1rem;
  margin-bottom: 6px;
}

.product-info p {
  color: var(--color-text-muted);
  font-size: 0.95rem;
  max-width: 480px;
}

.contact {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  text-align: center;
}

.contact h2 {
  font-size: 1.75rem;
  margin-bottom: 16px;
}

.contact p {
  color: var(--color-text-muted);
  max-width: 560px;
  margin: 0 auto 32px;
  font-size: 1.05rem;
}

.contact-details {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin: 0 auto 32px;
  font-size: 1rem;
}

.contact-details li span:first-child {
  color: var(--color-text-muted);
  margin-right: 6px;
}

.contact-details a {
  color: var(--color-primary);
  font-weight: 600;
}

.contact-details a:hover {
  text-decoration: underline;
}

.site-footer {
  padding: 28px 0;
  text-align: center;
  color: var(--color-text-muted);
  font-size: 0.9rem;
  border-top: 1px solid var(--color-border);
  margin-bottom: 0;
}

/* Mobile bottom navigation */
.bottom-nav {
  display: none;
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  padding: 6px 4px calc(6px + env(safe-area-inset-bottom, 0px));
  box-shadow: 0 -4px 16px rgba(0, 0, 0, 0.06);
}

.bottom-nav-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 2px;
  flex: 1;
  color: var(--color-text-muted);
  font-size: 0.65rem;
  padding: 4px 2px;
  border-radius: 8px;
  transition: color 0.15s ease;
}

.bottom-nav-item svg {
  width: 21px;
  height: 21px;
  stroke: currentColor;
  fill: none;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.bottom-nav-item.active {
  color: var(--color-primary);
}

@media (max-width: 720px) {
  .site-nav a {
    display: none;
  }

  .site-nav {
    gap: 10px;
  }

  .bottom-nav {
    display: flex;
  }

  body {
    padding-bottom: 66px;
  }

  .site-footer {
    padding-bottom: calc(28px + 66px);
  }
}

@media (max-width: 640px) {
  section {
    padding: 48px 0;
  }
}