/* ============================================================
   THU PHÁT PLASTIC — Main Stylesheet
   ============================================================ */

/* ---------- CSS Variables ---------- */
:root {
  --blue-900:  #0D2B6B;
  --blue-800:  #1565C0;
  --blue-700:  #1976D2;
  --blue-500:  #42A5F5;
  --blue-100:  #E3F2FD;
  --blue-50:   #EFF6FF;
  --teal:      #0097A7;
  --white:     #FFFFFF;
  --gray-50:   #FAFAFA;
  --gray-100:  #F5F5F5;
  --gray-200:  #EEEEEE;
  --gray-300:  #E0E0E0;
  --gray-400:  #BDBDBD;
  --gray-500:  #9E9E9E;
  --gray-600:  #757575;
  --gray-700:  #616161;
  --gray-800:  #424242;
  --gray-900:  #212121;
  --shadow-sm: 0 1px 3px rgba(0,0,0,.08);
  --shadow:    0 4px 12px rgba(0,0,0,.10);
  --shadow-md: 0 8px 24px rgba(0,0,0,.12);
  --shadow-lg: 0 16px 40px rgba(0,0,0,.14);
  --radius-sm: 6px;
  --radius:    10px;
  --radius-lg: 16px;
  --transition: .3s cubic-bezier(.4,0,.2,1);
  --header-h:  70px;
}

/* ---------- Reset & Base ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: 'Inter', 'Segoe UI', system-ui, sans-serif;
  color: var(--gray-900);
  background: var(--white);
  line-height: 1.6;
  overflow-x: hidden;
}
img { display: block; max-width: 100%; }
a  { text-decoration: none; color: inherit; }
ul { list-style: none; }
button { cursor: pointer; border: none; background: none; font-family: inherit; }

/* ---------- Typography ---------- */
.section-title {
  font-size: clamp(1.5rem, 3vw, 2.2rem);
  font-weight: 700;
  color: var(--gray-900);
  line-height: 1.25;
}
.section-subtitle {
  font-size: 1rem;
  color: var(--gray-600);
  margin-top: .5rem;
}
.section-label {
  display: inline-block;
  font-size: .75rem;
  font-weight: 600;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--blue-700);
  margin-bottom: .75rem;
}

/* ---------- Utilities ---------- */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.25rem;
}
.section-pad { padding: 80px 0; }
.text-center { text-align: center; }
.flex-center { display: flex; align-items: center; justify-content: center; }
.btn {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  padding: .75rem 1.75rem;
  border-radius: 50px;
  font-size: .9375rem;
  font-weight: 600;
  transition: var(--transition);
  white-space: nowrap;
}
.btn-primary {
  background: var(--blue-800);
  color: var(--white);
  box-shadow: 0 4px 14px rgba(21,101,192,.35);
}
.btn-primary:hover {
  background: var(--blue-900);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(21,101,192,.45);
}
.btn-outline {
  border: 2px solid var(--white);
  color: var(--white);
}
.btn-outline:hover {
  background: var(--white);
  color: var(--blue-800);
}
.badge {
  display: inline-block;
  padding: .2rem .65rem;
  border-radius: 50px;
  font-size: .72rem;
  font-weight: 600;
  letter-spacing: .04em;
  text-transform: uppercase;
}
.badge-lldpe  { background: #E3F2FD; color: #1565C0; }
.badge-pp     { background: #E8F5E9; color: #2E7D32; }
.badge-baolong{ background: #FFF3E0; color: #E65100; }
.badge-cuonpe { background: #F3E5F5; color: #6A1B9A; }

/* ============================================================
   HEADER
   ============================================================ */
#header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  height: var(--header-h);
  background: rgba(255,255,255,.97);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--gray-200);
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition);
}
#header.scrolled {
  box-shadow: 0 4px 20px rgba(0,0,0,.12);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

/* Logo */
.logo {
  display: flex;
  align-items: center;
  gap: .75rem;
  flex-shrink: 0;
}
.logo-img {
  height: 44px;
  width: auto;
  object-fit: contain;
}
.logo-text {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}
.logo-text .brand   { font-size: 1rem; font-weight: 800; color: var(--blue-800); letter-spacing: .02em; }
.logo-text .tagline { font-size: .65rem; color: var(--gray-500); letter-spacing: .06em; text-transform: uppercase; }

/* Nav */
.nav { display: flex; align-items: center; gap: .25rem; }
.nav-link {
  position: relative;
  padding: .5rem .875rem;
  font-size: .9rem;
  font-weight: 500;
  color: var(--gray-700);
  border-radius: var(--radius-sm);
  transition: color var(--transition), background var(--transition);
}
.nav-link::after {
  content: '';
  position: absolute;
  bottom: 2px; left: 50%;
  width: 0; height: 2px;
  background: var(--blue-800);
  border-radius: 2px;
  transform: translateX(-50%);
  transition: width var(--transition);
}
.nav-link:hover, .nav-link.active { color: var(--blue-800); }
.nav-link:hover::after, .nav-link.active::after { width: 60%; }

/* Hamburger */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: .5rem;
  border-radius: var(--radius-sm);
  transition: background var(--transition);
}
.hamburger:hover { background: var(--gray-100); }
.hamburger span {
  display: block;
  width: 24px; height: 2px;
  background: var(--gray-800);
  border-radius: 2px;
  transition: var(--transition);
}
.hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; transform: scaleX(0); }
.hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* Mobile menu */
.mobile-menu {
  display: none;
  position: fixed;
  top: var(--header-h); left: 0; right: 0;
  background: var(--white);
  border-bottom: 1px solid var(--gray-200);
  box-shadow: var(--shadow-md);
  padding: 1rem 1.25rem;
  flex-direction: column;
  gap: .25rem;
  z-index: 999;
}
.mobile-menu.open { display: flex; }
.mobile-nav-link {
  padding: .75rem 1rem;
  font-size: .95rem;
  font-weight: 500;
  color: var(--gray-700);
  border-radius: var(--radius-sm);
  transition: background var(--transition), color var(--transition);
}
.mobile-nav-link:hover { background: var(--blue-50); color: var(--blue-800); }

/* ============================================================
   HERO SLIDER
   ============================================================ */
.hero {
  position: relative;
  height: 100vh;
  min-height: 560px;
  max-height: 860px;
  overflow: hidden;
  margin-top: var(--header-h);
}
.slides-wrapper {
  display: flex;
  height: 100%;
  transition: transform .7s cubic-bezier(.77,0,.175,1);
}
.slide {
  min-width: 100%;
  height: 100%;
  position: relative;
  overflow: hidden;
}
.slide-bg {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-position: center;
  transform: scale(1.05);
  transition: transform 8s ease;
}
.slide.active .slide-bg { transform: scale(1); }

/* Gradient fallback slides */
.slide:nth-child(1) .slide-bg {
  background-image:
    linear-gradient(135deg, #0D2B6B 0%, #1565C0 50%, #0097A7 100%);
}
.slide:nth-child(2) .slide-bg {
  background-image:
    linear-gradient(135deg, #1a237e 0%, #283593 40%, #1976D2 100%);
}
.slide:nth-child(3) .slide-bg {
  background-image:
    linear-gradient(135deg, #006064 0%, #0097A7 50%, #1565C0 100%);
}

/* Overlay pattern */
.slide-overlay {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(to right, rgba(0,0,0,.55) 0%, rgba(0,0,0,.25) 60%, rgba(0,0,0,.1) 100%);
}
.slide-overlay::after {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    radial-gradient(circle, rgba(255,255,255,.04) 1px, transparent 1px);
  background-size: 32px 32px;
}

/* Slide Content */
.slide-content {
  position: relative;
  z-index: 2;
  height: 100%;
  display: flex;
  align-items: center;
}
.slide-text {
  max-width: 660px;
  color: var(--white);
  padding: 0 1.25rem;
}
.slide-label {
  font-size: .8rem;
  font-weight: 600;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: rgba(255,255,255,.75);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: .5rem;
}
.slide-label::before {
  content: '';
  display: inline-block;
  width: 32px; height: 2px;
  background: var(--blue-500);
}
.slide-title {
  font-size: clamp(1.8rem, 4vw, 3rem);
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 1rem;
  text-shadow: 0 2px 12px rgba(0,0,0,.3);
}
.slide-desc {
  font-size: clamp(.9rem, 1.5vw, 1.05rem);
  color: rgba(255,255,255,.85);
  margin-bottom: 2rem;
  max-width: 520px;
  line-height: 1.7;
}
.slide-cta { display: flex; gap: 1rem; flex-wrap: wrap; }

/* Slider Controls */
.slider-arrows {
  position: absolute;
  bottom: 2.5rem; right: 2rem;
  display: flex; gap: .5rem;
  z-index: 10;
}
.arrow-btn {
  width: 44px; height: 44px;
  border-radius: 50%;
  background: rgba(255,255,255,.15);
  border: 1.5px solid rgba(255,255,255,.35);
  color: var(--white);
  display: flex; align-items: center; justify-content: center;
  transition: var(--transition);
  font-size: 1.1rem;
}
.arrow-btn:hover {
  background: rgba(255,255,255,.3);
  border-color: rgba(255,255,255,.6);
}

.slider-dots {
  position: absolute;
  bottom: 2rem; left: 50%;
  transform: translateX(-50%);
  display: flex; gap: .5rem;
  z-index: 10;
}
.dot {
  width: 8px; height: 8px;
  border-radius: 50%;
  background: rgba(255,255,255,.4);
  transition: var(--transition);
}
.dot.active {
  width: 28px;
  border-radius: 4px;
  background: var(--white);
}

/* Slide counter */
.slide-counter {
  position: absolute;
  top: 2rem; right: 2rem;
  color: rgba(255,255,255,.7);
  font-size: .85rem;
  font-weight: 500;
  z-index: 10;
}
.slide-counter .current { font-size: 1.5rem; font-weight: 700; color: var(--white); }

/* ============================================================
   ABOUT
   ============================================================ */
.about { background: var(--gray-50); }
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
}
.about-text-col .section-label { display: block; }
.about-description {
  font-size: 1rem;
  color: var(--gray-700);
  line-height: 1.85;
  margin-top: 1.25rem;
}
.about-stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-top: 2.5rem;
}
.stat-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 1.25rem;
  border: 1px solid var(--gray-200);
  text-align: center;
  transition: var(--transition);
}
.stat-card:hover { border-color: var(--blue-500); box-shadow: var(--shadow); }
.stat-number {
  font-size: 2rem;
  font-weight: 800;
  color: var(--blue-800);
  line-height: 1;
}
.stat-label { font-size: .8rem; color: var(--gray-600); margin-top: .35rem; }

/* Features grid */
.features-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}
.feature-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 1.5rem;
  border: 1px solid var(--gray-200);
  transition: var(--transition);
}
.feature-card:hover {
  border-color: var(--blue-500);
  box-shadow: 0 4px 20px rgba(21,101,192,.1);
  transform: translateY(-3px);
}
.feature-icon {
  width: 48px; height: 48px;
  border-radius: var(--radius-sm);
  background: var(--blue-50);
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 1rem;
  font-size: 1.4rem;
}
.feature-title {
  font-size: .9375rem;
  font-weight: 700;
  color: var(--gray-900);
  margin-bottom: .35rem;
}
.feature-desc { font-size: .85rem; color: var(--gray-600); line-height: 1.6; }

/* ============================================================
   PRODUCTS
   ============================================================ */
.products { background: var(--white); }
.products-header { text-align: center; margin-bottom: 3rem; }

/* Filter Tabs */
.filter-tabs {
  display: flex;
  gap: .5rem;
  justify-content: center;
  flex-wrap: wrap;
  margin-top: 2rem;
}
.filter-btn {
  padding: .55rem 1.35rem;
  border-radius: 50px;
  font-size: .875rem;
  font-weight: 500;
  color: var(--gray-600);
  background: var(--gray-100);
  border: 1.5px solid transparent;
  transition: var(--transition);
}
.filter-btn:hover { color: var(--blue-800); background: var(--blue-50); }
.filter-btn.active {
  background: var(--blue-800);
  color: var(--white);
  border-color: var(--blue-800);
  box-shadow: 0 4px 12px rgba(21,101,192,.3);
}

/* Product Grid */
.products-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 1.5rem;
  margin-top: 2.5rem;
}

/* Product Card */
.product-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--gray-200);
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  animation: fadeInUp .4s ease both;
}
.product-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 12px 32px rgba(21,101,192,.15);
  border-color: var(--blue-500);
}

/* Card Image */
.card-img-wrap {
  position: relative;
  aspect-ratio: 4/3;
  overflow: hidden;
  background: var(--gray-100);
}
.card-img-wrap img {
  width: 100%; height: 100%;
  object-fit: cover;
  transition: transform .5s ease;
}
.product-card:hover .card-img-wrap img { transform: scale(1.06); }

/* Placeholder when image missing */
.img-placeholder {
  width: 100%; height: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  font-size: .8rem;
  font-weight: 600;
  color: rgba(255,255,255,.9);
  letter-spacing: .05em;
  text-align: center;
  padding: 1rem;
}
.placeholder-icon { font-size: 2.5rem; margin-bottom: .5rem; opacity: .85; }

/* Placeholder gradients per type */
.ph-lldpe   { background: linear-gradient(135deg, #1565C0, #42A5F5); }
.ph-pp      { background: linear-gradient(135deg, #2E7D32, #66BB6A); }
.ph-baolong { background: linear-gradient(135deg, #E65100, #FFA726); }
.ph-cuonpe  { background: linear-gradient(135deg, #6A1B9A, #AB47BC); }

.card-type-badge {
  position: absolute;
  top: .75rem; left: .75rem;
}
.card-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(to top, rgba(0,0,0,.45) 0%, transparent 60%);
  opacity: 0;
  transition: opacity var(--transition);
}
.product-card:hover .card-overlay { opacity: 1; }
.card-action {
  position: absolute;
  bottom: 1rem; left: 50%;
  transform: translateX(-50%) translateY(8px);
  opacity: 0;
  transition: var(--transition);
  white-space: nowrap;
}
.product-card:hover .card-action {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* Card Body */
.card-body {
  padding: 1.1rem 1.25rem 1.25rem;
  flex: 1;
  display: flex;
  flex-direction: column;
}
.card-name {
  font-size: 1rem;
  font-weight: 700;
  color: var(--gray-900);
  margin-bottom: .4rem;
}
.card-desc {
  font-size: .8375rem;
  color: var(--gray-600);
  line-height: 1.6;
  flex: 1;
}
.card-footer {
  margin-top: .875rem;
  padding-top: .875rem;
  border-top: 1px solid var(--gray-200);
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.card-contact {
  font-size: .8rem;
  font-weight: 600;
  color: var(--blue-800);
  display: flex;
  align-items: center;
  gap: .3rem;
  transition: color var(--transition);
}
.card-contact:hover { color: var(--blue-900); }

/* Empty state */
.no-products {
  grid-column: 1 / -1;
  text-align: center;
  padding: 4rem 1rem;
  color: var(--gray-500);
}
.no-products-icon { font-size: 3rem; margin-bottom: 1rem; }

/* Animations */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(20px); }
  to   { opacity: 1; transform: translateY(0); }
}
.product-card.hidden { display: none; }

/* ============================================================
   CTA BAND
   ============================================================ */
.cta-band {
  background: linear-gradient(135deg, var(--blue-900) 0%, var(--blue-800) 50%, var(--teal) 100%);
  padding: 70px 0;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.cta-band::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image: radial-gradient(circle, rgba(255,255,255,.05) 1px, transparent 1px);
  background-size: 28px 28px;
}
.cta-band-inner { position: relative; z-index: 1; }
.cta-band .section-title { color: var(--white); }
.cta-band .section-subtitle { color: rgba(255,255,255,.75); font-size: 1.05rem; margin-top: .75rem; }
.cta-buttons { display: flex; gap: 1rem; justify-content: center; flex-wrap: wrap; margin-top: 2rem; }
.btn-white { background: var(--white); color: var(--blue-800); font-weight: 700; }
.btn-white:hover {
  background: var(--gray-100);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0,0,0,.2);
}

/* ============================================================
   FOOTER
   ============================================================ */
footer {
  background: var(--gray-900);
  color: var(--gray-400);
  padding: 60px 0 0;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr 1fr;
  gap: 3rem;
}
.footer-brand .logo-text .brand { color: var(--white); font-size: 1.1rem; }
.footer-brand .logo-text .tagline { color: var(--gray-500); }
.footer-desc {
  font-size: .875rem;
  line-height: 1.75;
  margin-top: 1rem;
  color: var(--gray-500);
  max-width: 300px;
}

.footer-col-title {
  font-size: .8rem;
  font-weight: 700;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--gray-300);
  margin-bottom: 1.25rem;
}
.footer-links { display: flex; flex-direction: column; gap: .6rem; }
.footer-link {
  font-size: .875rem;
  color: var(--gray-500);
  transition: color var(--transition);
}
.footer-link:hover { color: var(--white); }

.contact-item {
  display: flex;
  align-items: flex-start;
  gap: .75rem;
  margin-bottom: .875rem;
  font-size: .875rem;
  color: var(--gray-500);
}
.contact-icon {
  flex-shrink: 0;
  width: 32px; height: 32px;
  border-radius: var(--radius-sm);
  background: rgba(255,255,255,.06);
  display: flex; align-items: center; justify-content: center;
  font-size: 1rem;
}
.contact-text a { color: var(--gray-400); transition: color var(--transition); }
.contact-text a:hover { color: var(--white); }
.contact-label { font-size: .72rem; color: var(--gray-600); margin-bottom: .1rem; }

.footer-bottom {
  margin-top: 3rem;
  border-top: 1px solid rgba(255,255,255,.07);
  padding: 1.25rem 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: .75rem;
  font-size: .8125rem;
  color: var(--gray-600);
}
.footer-bottom a { color: var(--gray-500); }
.footer-bottom a:hover { color: var(--white); }

/* ============================================================
   SCROLL TO TOP
   ============================================================ */
#scrollTop {
  position: fixed;
  bottom: 2rem; right: 2rem;
  width: 44px; height: 44px;
  border-radius: 50%;
  background: var(--blue-800);
  color: var(--white);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.1rem;
  box-shadow: 0 4px 16px rgba(21,101,192,.4);
  z-index: 900;
  opacity: 0;
  pointer-events: none;
  transform: translateY(12px);
  transition: var(--transition);
}
#scrollTop.visible {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}
#scrollTop:hover { background: var(--blue-900); transform: translateY(-2px); }

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 1024px) {
  .about-grid { gap: 2.5rem; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
  :root { --header-h: 62px; }

  .nav       { display: none; }
  .hamburger { display: flex; }

  .hero { max-height: 640px; }
  .slide-title { font-size: 1.7rem; }

  .about-grid { grid-template-columns: 1fr; gap: 2rem; }
  .features-grid { grid-template-columns: 1fr; }
  .about-stats { grid-template-columns: repeat(2, 1fr); }

  .footer-grid { grid-template-columns: 1fr; gap: 2rem; }

  .footer-bottom { flex-direction: column; text-align: center; }

  .products-grid { grid-template-columns: repeat(auto-fill, minmax(180px, 1fr)); gap: 1rem; }
  .section-pad { padding: 56px 0; }
}

@media (max-width: 480px) {
  .hero { max-height: 580px; }
  .slide-cta .btn-outline { display: none; }
  .products-grid { grid-template-columns: 1fr 1fr; gap: .875rem; }
  .card-body { padding: .875rem; }
  .filter-tabs { gap: .375rem; }
  .filter-btn { padding: .45rem 1rem; font-size: .8rem; }
}