:root {
  --primary-dark: #06284b;
  --primary: #005691;
  --primary-light: #0088cc;
  --accent-cyan: #00b4d8;
  --accent-green: #2b9348;
  --accent-orange: #f77f00;
  --accent-orange-hover: #d66800;
  --bg-light: #f4f9fd;
  --bg-white: #ffffff;
  --text-main: #1b2a38;
  --text-muted: #52667a;
  --border-color: #dbe9f4;
  --shadow-sm: 0 4px 14px rgba(6, 40, 75, 0.06);
  --shadow-md: 0 10px 30px rgba(6, 40, 75, 0.1);
  --shadow-lg: 0 18px 42px rgba(6, 40, 75, 0.16);
  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 24px;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: 'Be Vietnam Pro', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  color: var(--text-main);
  background-color: var(--bg-light);
  line-height: 1.65;
  overflow-x: hidden;
  padding-bottom: 76px;
}

@media (min-width: 992px) {
  body {
    padding-bottom: 0;
  }
}

a {
  text-decoration: none;
  color: inherit;
  transition: all 0.25s ease;
}

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

.container {
  width: 100%;
  max-width: 1260px;
  margin: 0 auto;
  padding: 0 18px;
}

/* TOP BAR - Clean single line for Mobile & Desktop */
.topbar {
  background: var(--primary-dark);
  color: #e2f1ff;
  font-size: 0.85rem;
  padding: 7px 0;
}

.topbar-inner {
  display: flex;
  justify-content: center;
  align-items: center;
  text-align: center;
}

.topbar-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: rgba(0, 180, 216, 0.2);
  border: 1px solid rgba(0, 180, 216, 0.45);
  color: #90e0ef;
  padding: 3px 14px;
  border-radius: 99px;
  font-weight: 700;
  font-size: 0.82rem;
}

/* HEADER & NAVIGATION */
.header {
  position: sticky;
  top: 0;
  z-index: 900;
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: blur(12px);
  box-shadow: 0 2px 18px rgba(6, 40, 75, 0.08);
  border-bottom: 1px solid var(--border-color);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
  gap: 12px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
}

.brand-logo {
  height: 48px;
  width: auto;
  object-fit: contain;
}

.brand-text {
  display: flex;
  flex-direction: column;
}

.brand-name {
  font-size: 1.45rem;
  font-weight: 800;
  letter-spacing: -0.5px;
  color: var(--primary);
  line-height: 1.1;
}

.brand-name span {
  color: var(--accent-cyan);
}

.brand-tagline {
  font-size: 0.7rem;
  font-weight: 700;
  color: var(--primary-dark);
  text-transform: uppercase;
  letter-spacing: 0.3px;
}

.nav-menu {
  display: none;
  align-items: center;
  gap: 20px;
  list-style: none;
}

.nav-menu a {
  font-weight: 600;
  font-size: 0.94rem;
  color: var(--primary-dark);
  padding: 6px 4px;
  position: relative;
}

.nav-menu a::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: 0;
  width: 0;
  height: 2px;
  background: var(--primary-light);
  transition: width 0.25s ease;
}

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

.nav-menu a:hover::after {
  width: 100%;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

.btn-hotline {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: linear-gradient(135deg, var(--accent-orange), #ff5400);
  color: #fff;
  font-weight: 700;
  font-size: 0.88rem;
  padding: 9px 15px;
  border-radius: 99px;
  box-shadow: 0 6px 16px rgba(247, 127, 0, 0.3);
}

.btn-hotline:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 22px rgba(247, 127, 0, 0.42);
}

.mobile-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  border-radius: 10px;
  border: 1px solid var(--border-color);
  background: var(--bg-light);
  color: var(--primary-dark);
  font-size: 1.35rem;
  cursor: pointer;
}

@media (min-width: 992px) {
  .nav-menu {
    display: flex;
  }
  .mobile-toggle {
    display: none;
  }
}

/* MOBILE DRAWER */
.mobile-drawer {
  display: none;
  background: #fff;
  border-bottom: 2px solid var(--border-color);
  padding: 16px 18px 22px;
  box-shadow: var(--shadow-md);
}

.mobile-drawer.open {
  display: block;
}

.mobile-drawer ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.mobile-drawer a {
  display: block;
  padding: 10px 14px;
  border-radius: 10px;
  font-weight: 600;
  color: var(--primary-dark);
  background: var(--bg-light);
}

.mobile-drawer a:hover {
  background: #e1f2fe;
  color: var(--primary);
}

/* HERO SECTION */
.hero {
  background: radial-gradient(circle at top right, #0077b6 0%, #03254c 65%, #021831 100%);
  color: #fff;
  padding: 40px 0 56px;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -120px;
  right: -120px;
  width: 420px;
  height: 420px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(0, 180, 216, 0.25) 0%, transparent 70%);
  pointer-events: none;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  align-items: center;
}

@media (min-width: 992px) {
  .hero-grid {
    grid-template-columns: 1.05fr 0.95fr;
    gap: 42px;
  }
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(0, 180, 216, 0.2);
  border: 1px solid rgba(144, 224, 239, 0.4);
  color: #90e0ef;
  font-weight: 700;
  font-size: 0.82rem;
  padding: 6px 14px;
  border-radius: 99px;
  margin-bottom: 14px;
}

.hero h1 {
  font-size: clamp(1.75rem, 3.8vw, 2.75rem);
  font-weight: 800;
  line-height: 1.22;
  margin-bottom: 14px;
  letter-spacing: -0.4px;
}

.hero h1 .highlight {
  color: #48cae4;
}

.hero-desc {
  font-size: 1.02rem;
  color: #d6ecff;
  margin-bottom: 22px;
}

.hero-features {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
  margin-bottom: 26px;
}

@media (min-width: 576px) {
  .hero-features {
    grid-template-columns: 1fr 1fr;
  }
}

.hero-feature-item {
  display: flex;
  align-items: center;
  gap: 10px;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.14);
  padding: 10px 14px;
  border-radius: 12px;
  font-size: 0.89rem;
  font-weight: 500;
}

.hero-feature-item i {
  color: #52b788;
  font-style: normal;
  font-weight: 800;
}

.hero-cta-group {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  background: linear-gradient(135deg, var(--accent-orange), #ff5400);
  color: #fff;
  font-weight: 700;
  font-size: 0.98rem;
  padding: 13px 24px;
  border-radius: 12px;
  border: none;
  cursor: pointer;
  box-shadow: 0 8px 22px rgba(247, 127, 0, 0.32);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 26px rgba(247, 127, 0, 0.44);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  background: rgba(255, 255, 255, 0.12);
  border: 1px solid rgba(255, 255, 255, 0.3);
  color: #fff;
  font-weight: 700;
  font-size: 0.98rem;
  padding: 13px 22px;
  border-radius: 12px;
  cursor: pointer;
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.22);
}

.hero-visual-card {
  background: #fff;
  padding: 10px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
}

.hero-visual-card img {
  border-radius: 10px;
  width: 100%;
  cursor: zoom-in;
}

.zoom-hint {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-top: 8px;
  font-size: 0.8rem;
  color: var(--text-muted);
  font-weight: 600;
}

/* SECTION HEADERS */
.section {
  padding: 58px 0;
}

.section-alt {
  background: #fff;
}

.section-header {
  text-align: center;
  max-width: 820px;
  margin: 0 auto 38px;
}

.section-tag {
  display: inline-block;
  background: #e0f4ff;
  color: var(--primary);
  font-weight: 700;
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.6px;
  padding: 6px 14px;
  border-radius: 99px;
  margin-bottom: 12px;
}

.section-title {
  font-size: clamp(1.5rem, 3.2vw, 2.25rem);
  font-weight: 800;
  color: var(--primary-dark);
  line-height: 1.25;
  margin-bottom: 12px;
}

.section-subtitle {
  color: var(--text-muted);
  font-size: 1rem;
}

/* QUICK NAVIGATION TABS FOR 5 WATER TYPES */
.water-nav-pills {
  display: flex;
  gap: 10px;
  overflow-x: auto;
  padding-bottom: 12px;
  margin-bottom: 30px;
  scrollbar-width: thin;
  -webkit-overflow-scrolling: touch;
}

.water-pill {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 11px 16px;
  border-radius: 14px;
  background: #fff;
  border: 2px solid var(--border-color);
  color: var(--primary-dark);
  font-weight: 700;
  font-size: 0.9rem;
  cursor: pointer;
  transition: all 0.2s ease;
  box-shadow: var(--shadow-sm);
}

.water-pill .num {
  width: 25px;
  height: 25px;
  border-radius: 50%;
  background: #e3f2fd;
  color: var(--primary);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 0.8rem;
  font-weight: 800;
}

.water-pill:hover,
.water-pill.active {
  background: var(--primary);
  border-color: var(--primary);
  color: #fff;
  transform: translateY(-2px);
}

.water-pill:hover .num,
.water-pill.active .num {
  background: #fff;
  color: var(--primary);
}

/* 5 WATER TYPE IN-DEPTH ARTICLES */
.water-articles-list {
  display: flex;
  flex-direction: column;
  gap: 44px;
}

.water-article-card {
  background: #fff;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-md);
  overflow: hidden;
  scroll-margin-top: 90px;
}

.water-article-banner {
  background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary) 100%);
  color: #fff;
  padding: 22px 26px;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 14px;
}

.water-article-title-wrap {
  display: flex;
  align-items: center;
  gap: 14px;
}

.water-badge-num {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  background: rgba(0, 180, 216, 0.25);
  border: 2px solid #48cae4;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  font-weight: 800;
  color: #90e0ef;
  flex-shrink: 0;
}

.water-article-banner h3 {
  font-size: clamp(1.2rem, 2.4vw, 1.6rem);
  font-weight: 800;
  line-height: 1.25;
  margin-bottom: 4px;
}

.water-article-banner p {
  color: #cae9ff;
  font-size: 0.92rem;
}

.water-tag-target {
  background: rgba(255, 255, 255, 0.14);
  border: 1px solid rgba(255, 255, 255, 0.25);
  padding: 7px 14px;
  border-radius: 99px;
  font-size: 0.84rem;
  font-weight: 600;
  color: #fff;
}

.water-article-body {
  padding: 26px;
}

@media (max-width: 767px) {
  .water-article-banner {
    padding: 18px 16px;
  }
  .water-article-body {
    padding: 18px 14px;
  }
}

.water-top-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
  align-items: start;
  margin-bottom: 24px;
}

@media (min-width: 992px) {
  .water-top-grid {
    grid-template-columns: 1.05fr 0.95fr;
  }
}

.water-infographic-box {
  background: var(--bg-light);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 10px;
}

.water-infographic-box img {
  border-radius: 10px;
  width: 100%;
  cursor: zoom-in;
}

.water-editorial h4 {
  font-size: 1.16rem;
  color: var(--primary-dark);
  margin-bottom: 10px;
}

.water-editorial p {
  color: var(--text-main);
  margin-bottom: 12px;
  font-size: 0.95rem;
}

.problem-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin: 14px 0;
}

.problem-item {
  background: #fff8f6;
  border-left: 4px solid #e63946;
  padding: 11px 14px;
  border-radius: 0 10px 10px 0;
}

.problem-item strong {
  display: block;
  color: #b51724;
  font-size: 0.94rem;
  margin-bottom: 3px;
}

.problem-item span {
  font-size: 0.9rem;
  color: var(--text-main);
}

/* SOLUTION BOX INSIDE EACH WATER TYPE */
.solution-box {
  background: linear-gradient(135deg, #f0f9ff 0%, #e6f4ea 100%);
  border: 2px solid #90e0ef;
  border-radius: var(--radius-md);
  padding: 22px;
}

.solution-box-header {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 10px;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid rgba(0, 86, 145, 0.15);
}

.solution-box-header h4 {
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--primary-dark);
}

.solution-priority-badge {
  background: var(--primary);
  color: #fff;
  font-weight: 700;
  font-size: 0.84rem;
  padding: 6px 14px;
  border-radius: 99px;
}

.solution-steps {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin-bottom: 18px;
}

@media (min-width: 768px) {
  .solution-steps {
    grid-template-columns: repeat(3, 1fr);
  }
}

.solution-step-card {
  background: #fff;
  border-radius: 12px;
  padding: 15px;
  border: 1px solid rgba(0, 86, 145, 0.12);
  box-shadow: var(--shadow-sm);
}

.solution-step-card .step-tag {
  display: inline-block;
  font-size: 0.74rem;
  font-weight: 800;
  text-transform: uppercase;
  color: var(--primary-light);
  background: #e1f4ff;
  padding: 3px 9px;
  border-radius: 99px;
  margin-bottom: 6px;
}

.solution-step-card h5 {
  font-size: 0.98rem;
  color: var(--primary-dark);
  margin-bottom: 5px;
}

.solution-step-card p {
  font-size: 0.88rem;
  color: var(--text-muted);
}

/* CONTACT BOX AT THE BOTTOM OF SOLUTIONS & PRODUCT CARDS */
.solution-contact-box {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 14px;
  background: #fff;
  border: 2px solid var(--primary-light);
  padding: 14px 18px;
  border-radius: 14px;
}

.solution-contact-info {
  font-size: 0.92rem;
  color: var(--primary-dark);
}

.solution-contact-info strong {
  color: var(--primary);
  display: block;
  font-size: 0.98rem;
}

.solution-contact-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.btn-contact-call {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: linear-gradient(135deg, var(--accent-orange), #ff5400);
  color: #fff;
  font-weight: 700;
  font-size: 0.9rem;
  padding: 10px 18px;
  border-radius: 10px;
}

.btn-contact-zalo {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: #0068ff;
  color: #fff;
  font-weight: 700;
  font-size: 0.9rem;
  padding: 10px 18px;
  border-radius: 10px;
}

/* INTERACTIVE WATER SYMPTOM CHECKER */
.symptom-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin-bottom: 26px;
}

@media (min-width: 640px) {
  .symptom-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 992px) {
  .symptom-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.symptom-card {
  background: #fff;
  border: 2px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 18px;
  cursor: pointer;
  transition: all 0.22s ease;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.symptom-card:hover,
.symptom-card.active {
  border-color: var(--primary-light);
  background: #f0f9ff;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.symptom-card-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

.symptom-icon {
  font-size: 1.55rem;
}

.symptom-status {
  font-size: 0.75rem;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 99px;
  background: #eef6fc;
  color: var(--primary);
}

.symptom-card.active .symptom-status {
  background: var(--primary);
  color: #fff;
}

.symptom-card h4 {
  font-size: 1.02rem;
  color: var(--primary-dark);
}

.symptom-card p {
  font-size: 0.87rem;
  color: var(--text-muted);
}

.diagnosis-result-panel {
  background: linear-gradient(135deg, #06284b 0%, #005691 100%);
  color: #fff;
  border-radius: var(--radius-lg);
  padding: 26px;
  box-shadow: var(--shadow-lg);
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
  align-items: center;
}

@media (min-width: 992px) {
  .diagnosis-result-panel {
    grid-template-columns: 1.08fr 0.92fr;
  }
}

.diagnosis-badge {
  display: inline-block;
  background: rgba(72, 202, 228, 0.25);
  color: #90e0ef;
  padding: 5px 14px;
  border-radius: 99px;
  font-size: 0.8rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.diagnosis-result-panel h3 {
  font-size: 1.4rem;
  margin-bottom: 10px;
}

.diagnosis-result-panel p {
  color: #d8eeff;
  margin-bottom: 14px;
  font-size: 0.95rem;
}

.diagnosis-meta {
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 12px;
  padding: 14px 16px;
  margin-bottom: 18px;
}

.diagnosis-meta div {
  margin-bottom: 6px;
  font-size: 0.93rem;
}

.diagnosis-meta div:last-child {
  margin-bottom: 0;
}

.diagnosis-image-wrap {
  background: #fff;
  padding: 10px;
  border-radius: 14px;
}

.diagnosis-image-wrap img {
  border-radius: 10px;
  width: 100%;
  cursor: zoom-in;
}

/* PRODUCT INTRODUCTION CARDS (NO FIXED PRICE - WITH WARRANTY 12 MONTHS & CONTACT BOX) */
.warranty-highlight-banner {
  background: linear-gradient(135deg, #005691 0%, #06284b 100%);
  color: #fff;
  border-radius: var(--radius-md);
  padding: 18px 24px;
  margin: 0 auto 30px;
  max-width: 940px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  box-shadow: var(--shadow-sm);
}

.warranty-highlight-banner .w-left {
  display: flex;
  align-items: center;
  gap: 12px;
}

.warranty-pill {
  background: var(--accent-orange);
  color: #fff;
  font-weight: 800;
  font-size: 0.9rem;
  padding: 6px 14px;
  border-radius: 99px;
  white-space: nowrap;
}

.pricing-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
}

@media (min-width: 768px) {
  .pricing-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1100px) {
  .pricing-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.pricing-card {
  background: #fff;
  border-radius: var(--radius-md);
  border: 2px solid var(--border-color);
  padding: 24px 20px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  box-shadow: var(--shadow-sm);
  position: relative;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.pricing-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.pricing-card.popular {
  border-color: var(--primary-light);
}

.popular-ribbon {
  position: absolute;
  top: -13px;
  right: 18px;
  background: var(--primary-light);
  color: #fff;
  font-size: 0.75rem;
  font-weight: 800;
  padding: 4px 12px;
  border-radius: 99px;
  text-transform: uppercase;
}

.pricing-type {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--primary-light);
  text-transform: uppercase;
  margin-bottom: 6px;
}

.pricing-card h3 {
  font-size: 1.24rem;
  color: var(--primary-dark);
  margin-bottom: 10px;
}

.product-warranty-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: #fff4e6;
  border: 1px solid #ffd8a8;
  color: #d9480f;
  font-weight: 700;
  font-size: 0.84rem;
  padding: 6px 12px;
  border-radius: 8px;
  margin-bottom: 14px;
}

.pricing-features {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 9px;
  margin-bottom: 20px;
}

.pricing-features li {
  font-size: 0.91rem;
  color: var(--text-main);
  display: flex;
  align-items: flex-start;
  gap: 8px;
}

.pricing-features li::before {
  content: '✓';
  color: var(--accent-green);
  font-weight: 800;
}

/* BOTTOM CONTACT BOX INSIDE EACH PRODUCT CARD */
.card-contact-box {
  background: #f0f7ff;
  border: 1px solid #b8daff;
  border-radius: 12px;
  padding: 14px;
  text-align: center;
}

.card-contact-label {
  font-size: 0.84rem;
  font-weight: 700;
  color: var(--primary-dark);
  margin-bottom: 10px;
}

.card-contact-buttons {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}

.card-contact-buttons a {
  padding: 10px 8px;
  border-radius: 8px;
  font-weight: 700;
  font-size: 0.84rem;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 5px;
}

/* 11 Q&A SECTION */
.qa-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

@media (min-width: 992px) {
  .qa-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.qa-card {
  background: #fff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.qa-question {
  width: 100%;
  text-align: left;
  background: #fff;
  border: none;
  padding: 16px 18px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  cursor: pointer;
  font-family: inherit;
  font-size: 0.97rem;
  font-weight: 700;
  color: var(--primary-dark);
}

.qa-question:hover {
  background: #f7fbff;
}

.qa-q-left {
  display: flex;
  align-items: center;
  gap: 10px;
}

.qa-num {
  background: var(--primary);
  color: #fff;
  font-size: 0.78rem;
  font-weight: 800;
  padding: 4px 8px;
  border-radius: 8px;
  flex-shrink: 0;
}

.qa-icon {
  font-size: 1.1rem;
  color: var(--primary-light);
  transition: transform 0.25s ease;
}

.qa-card.open .qa-icon {
  transform: rotate(180deg);
}

.qa-answer {
  display: none;
  padding: 0 18px 18px;
  border-top: 1px solid var(--border-color);
  background: #fafdff;
}

.qa-card.open .qa-answer {
  display: block;
}

.qa-answer p {
  padding-top: 14px;
  margin-bottom: 12px;
  font-size: 0.92rem;
  color: var(--text-main);
}

.qa-answer img {
  border-radius: 10px;
  border: 1px solid var(--border-color);
  cursor: zoom-in;
}

/* TECH SPECS SECTION */
.specs-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
}

@media (min-width: 640px) {
  .specs-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 992px) {
  .specs-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.spec-card {
  background: #fff;
  padding: 22px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
}

.spec-card-icon {
  width: 46px;
  height: 46px;
  border-radius: 12px;
  background: #e1f4ff;
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
  margin-bottom: 12px;
}

.spec-card h4 {
  font-size: 1.06rem;
  color: var(--primary-dark);
  margin-bottom: 6px;
}

.spec-card p {
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* DEDICATED CONTACT & ADDRESS SECTION */
.consult-box {
  background: linear-gradient(135deg, #03254c 0%, #005691 100%);
  color: #fff;
  border-radius: var(--radius-lg);
  padding: 32px 22px;
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
  align-items: center;
  box-shadow: var(--shadow-lg);
}

@media (min-width: 992px) {
  .consult-box {
    grid-template-columns: 1.05fr 0.95fr;
    padding: 44px;
  }
}

.address-cards {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-top: 18px;
}

.address-card-item {
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.2);
  padding: 14px 18px;
  border-radius: 12px;
  font-size: 0.95rem;
}

.address-card-item strong {
  color: #ffd166;
}

.consult-form {
  background: #fff;
  color: var(--text-main);
  padding: 24px;
  border-radius: var(--radius-md);
}

.consult-form h4 {
  font-size: 1.2rem;
  color: var(--primary-dark);
  margin-bottom: 14px;
}

.form-group {
  margin-bottom: 13px;
}

.form-group label {
  display: block;
  font-size: 0.87rem;
  font-weight: 700;
  color: var(--primary-dark);
  margin-bottom: 5px;
}

.form-control {
  width: 100%;
  padding: 11px 13px;
  border-radius: 10px;
  border: 1px solid #c5d9e8;
  font-family: inherit;
  font-size: 0.94rem;
}

.form-control:focus {
  outline: none;
  border-color: var(--primary-light);
  box-shadow: 0 0 0 3px rgba(0, 136, 204, 0.15);
}

/* FOOTER */
.footer {
  background: #041c35;
  color: #c9e2f8;
  padding: 50px 0 34px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
  margin-bottom: 32px;
}

@media (min-width: 768px) {
  .footer-grid {
    grid-template-columns: 1.3fr 1fr 1.1fr;
  }
}

.footer h4 {
  color: #fff;
  font-size: 1.1rem;
  margin-bottom: 14px;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 9px;
  font-size: 0.92rem;
}

.footer-links a:hover {
  color: #48cae4;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  padding-top: 20px;
  text-align: center;
  font-size: 0.86rem;
  color: #8ab4d8;
}

/* MOBILE STICKY ACTION BAR */
.mobile-bottom-bar {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 950;
  background: #fff;
  border-top: 1px solid var(--border-color);
  box-shadow: 0 -4px 20px rgba(6, 40, 75, 0.12);
  display: grid;
  grid-template-columns: 1fr 1fr 1.2fr;
  gap: 8px;
  padding: 8px 10px;
}

@media (min-width: 992px) {
  .mobile-bottom-bar {
    display: none;
  }
}

.m-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 11px 8px;
  border-radius: 10px;
  font-weight: 700;
  font-size: 0.84rem;
  text-align: center;
}

.m-btn-zalo {
  background: #0068ff;
  color: #fff;
}

.m-btn-water {
  background: #e1f4ff;
  color: var(--primary-dark);
}

.m-btn-call {
  background: linear-gradient(135deg, var(--accent-orange), #ff5400);
  color: #fff;
}

/* DESKTOP FLOATING BUTTONS */
.desktop-float {
  display: none;
  position: fixed;
  right: 22px;
  bottom: 24px;
  z-index: 940;
  flex-direction: column;
  gap: 12px;
}

@media (min-width: 992px) {
  .desktop-float {
    display: flex;
  }
}

.float-btn {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 20px;
  border-radius: 99px;
  font-weight: 700;
  font-size: 0.92rem;
  color: #fff;
  box-shadow: var(--shadow-md);
}

.float-zalo {
  background: #0068ff;
}

.float-call {
  background: linear-gradient(135deg, var(--accent-orange), #ff5400);
}

/* LIGHTBOX MODAL FOR HIGH-RES IMAGES */
.lightbox {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 2000;
  background: rgba(2, 16, 31, 0.9);
  align-items: center;
  justify-content: center;
  padding: 20px;
}

.lightbox.active {
  display: flex;
}

.lightbox-content {
  max-width: 95vw;
  max-height: 90vh;
  border-radius: 12px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
}

.lightbox-close {
  position: absolute;
  top: 20px;
  right: 24px;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.2);
  color: #fff;
  border: none;
  font-size: 1.6rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
}