/* ===== Biến màu xanh lam chủ đạo ===== */
:root {
  --blue-900: #0c1e4a;
  --blue-800: #1e3a8a;
  --blue-700: #1d4ed8;
  --blue-600: #2563eb;
  --blue-500: #3b82f6;
  --blue-400: #60a5fa;
  --blue-100: #dbeafe;
  --blue-50: #eff6ff;
  --zalo-blue: #0068ff;
  --white: #ffffff;
  --gray-100: #f1f5f9;
  --gray-200: #e2e8f0;
  --gray-500: #64748b;
  --gray-700: #334155;
  --shadow: 0 4px 20px rgba(30, 58, 138, 0.12);
  --shadow-lg: 0 8px 32px rgba(30, 58, 138, 0.18);
  --radius: 12px;
  --transition: 0.25s ease;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Be Vietnam Pro', sans-serif;
  color: var(--gray-700);
  background: var(--blue-50);
  line-height: 1.6;
}

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

ul {
  list-style: none;
}

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

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* ===== Header & Menu ===== */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--white);
  box-shadow: var(--shadow);
}

.navbar {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.15rem;
  color: var(--blue-800);
}

.logo-icon {
  font-size: 1.5rem;
}

.logo-text strong {
  color: var(--blue-600);
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-link {
  padding: 8px 16px;
  border-radius: 8px;
  font-weight: 500;
  font-size: 0.95rem;
  color: var(--gray-700);
  transition: var(--transition);
}

.nav-link:hover,
.nav-link.active {
  background: var(--blue-100);
  color: var(--blue-700);
}

.nav-zalo {
  background: var(--zalo-blue) !important;
  color: var(--white) !important;
}

.nav-zalo:hover {
  background: #0055d4 !important;
  color: var(--white) !important;
}

.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.menu-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--blue-800);
  border-radius: 2px;
  transition: var(--transition);
}

/* ===== Hero ===== */
.hero {
  position: relative;
  background: linear-gradient(135deg, var(--blue-800) 0%, var(--blue-600) 60%, var(--blue-500) 100%);
  color: var(--white);
  padding: 80px 20px;
  overflow: hidden;
  min-height: 420px;
  display: flex;
  align-items: center;
}

.hero-content {
  max-width: 1200px;
  margin: 0 auto;
  position: relative;
  z-index: 2;
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 700;
  line-height: 1.25;
  margin-bottom: 16px;
}

.hero p {
  font-size: 1.1rem;
  opacity: 0.9;
  max-width: 560px;
  margin-bottom: 32px;
}

.hero-decoration {
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.hero-circle {
  position: absolute;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.06);
}

.hero-circle-1 {
  width: 400px;
  height: 400px;
  top: -100px;
  right: -80px;
}

.hero-circle-2 {
  width: 250px;
  height: 250px;
  bottom: -60px;
  right: 200px;
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: 50px;
  font-weight: 600;
  font-size: 1rem;
  cursor: pointer;
  border: none;
  transition: var(--transition);
}

.btn-primary {
  background: var(--white);
  color: var(--blue-700);
  margin-right: 12px;
}

.btn-primary:hover {
  background: var(--blue-100);
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}

.btn-outline {
  background: transparent;
  color: var(--white);
  border: 2px solid rgba(255, 255, 255, 0.7);
  margin-right: 12px;
}

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

.btn-zalo {
  background: var(--zalo-blue);
  color: var(--white);
}

.btn-zalo:hover {
  background: #0055d4;
  transform: translateY(-2px);
  box-shadow: 0 4px 16px rgba(0, 104, 255, 0.4);
}

.btn-large {
  padding: 16px 40px;
  font-size: 1.1rem;
}

/* ===== Products ===== */
.products {
  padding: 80px 0;
}

.section-header {
  text-align: center;
  margin-bottom: 48px;
}

.section-header h2 {
  font-size: 2rem;
  color: var(--blue-800);
  margin-bottom: 8px;
}

.section-header p {
  color: var(--gray-500);
  font-size: 1.05rem;
}

.product-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 24px;
}

.product-card {
  background: var(--white);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: var(--transition);
  display: flex;
  flex-direction: column;
}

.product-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
}

.product-image {
  height: 160px;
  background: linear-gradient(135deg, var(--blue-100), var(--blue-50));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3.5rem;
}

.product-body {
  padding: 20px;
  flex: 1;
  display: flex;
  flex-direction: column;
}

.product-category {
  font-size: 0.8rem;
  color: var(--blue-500);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 6px;
}

.product-name {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--blue-900);
  margin-bottom: 8px;
  line-height: 1.4;
}

.product-desc {
  font-size: 0.88rem;
  color: var(--gray-500);
  margin-bottom: 16px;
  flex: 1;
}

.product-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--gray-200);
  padding-top: 14px;
}

.product-price {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--blue-700);
}

.product-price span {
  font-size: 0.85rem;
  font-weight: 400;
  color: var(--gray-500);
}

.product-order {
  padding: 8px 16px;
  background: var(--blue-600);
  color: var(--white);
  border-radius: 50px;
  font-size: 0.85rem;
  font-weight: 600;
  transition: var(--transition);
}

.product-order:hover {
  background: var(--blue-700);
}

.product-loading,
.product-error {
  grid-column: 1 / -1;
  text-align: center;
  padding: 40px 20px;
  color: var(--gray-500);
  font-size: 1rem;
}

.product-error {
  color: #b91c1c;
  background: #fef2f2;
  border-radius: var(--radius);
  border: 1px solid #fecaca;
}

.product-error code {
  background: #fee2e2;
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.85rem;
}

/* ===== Bộ lọc & tìm kiếm sản phẩm ===== */
.product-filter {
  margin-bottom: 32px;
}

.filter-search {
  position: relative;
  max-width: 480px;
  margin: 0 auto 16px;
}

.filter-search svg {
  position: absolute;
  left: 16px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--gray-500);
  pointer-events: none;
}

.filter-search input {
  width: 100%;
  padding: 13px 18px 13px 46px;
  border: 2px solid var(--gray-200);
  border-radius: 999px;
  font-family: inherit;
  font-size: 1rem;
  color: var(--gray-700);
  background: var(--white);
  outline: none;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.filter-search input:focus {
  border-color: var(--blue-500);
  box-shadow: 0 0 0 4px var(--blue-100);
}

.filter-categories {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px;
}

.filter-btn {
  padding: 8px 16px;
  border: 1.5px solid var(--gray-200);
  border-radius: 999px;
  background: var(--white);
  color: var(--gray-700);
  font-family: inherit;
  font-size: 0.875rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition);
}

.filter-btn:hover {
  border-color: var(--blue-400);
  color: var(--blue-600);
}

.filter-btn.active {
  background: var(--blue-600);
  border-color: var(--blue-600);
  color: var(--white);
}

.filter-result {
  text-align: center;
  margin-top: 14px;
  font-size: 0.9rem;
  color: var(--gray-500);
}

.product-empty {
  grid-column: 1 / -1;
  text-align: center;
  padding: 48px 20px;
  color: var(--gray-500);
  font-size: 1rem;
  background: var(--white);
  border-radius: var(--radius);
  border: 1px dashed var(--gray-200);
}

.product-empty a {
  color: var(--blue-600);
  font-weight: 600;
  text-decoration: underline;
}

/* ===== Cameras ===== */
.cameras {
  padding: 80px 0;
  background: linear-gradient(180deg, var(--blue-900) 0%, var(--blue-800) 100%);
  color: var(--white);
}

.cameras .section-header h2 {
  color: var(--white);
}

.cameras .section-header p {
  color: rgba(255, 255, 255, 0.75);
  max-width: 640px;
  margin: 0 auto;
}

.section-badge {
  display: inline-block;
  background: rgba(255, 255, 255, 0.12);
  border: 1px solid rgba(255, 255, 255, 0.2);
  padding: 6px 16px;
  border-radius: 50px;
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 12px;
}

.camera-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 24px;
  margin-bottom: 48px;
}

.camera-card {
  background: var(--white);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  color: var(--gray-700);
}

.camera-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.25);
}

.camera-image {
  position: relative;
  height: 180px;
  background: linear-gradient(135deg, #1a2744, var(--blue-700));
  display: flex;
  align-items: center;
  justify-content: center;
}

.camera-icon {
  font-size: 4rem;
}

.camera-badge {
  position: absolute;
  top: 12px;
  left: 12px;
  background: var(--blue-500);
  color: var(--white);
  padding: 4px 12px;
  border-radius: 50px;
  font-size: 0.75rem;
  font-weight: 600;
}

.camera-body {
  padding: 20px;
  flex: 1;
  display: flex;
  flex-direction: column;
}

.camera-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 10px;
}

.camera-type {
  font-size: 0.78rem;
  color: var(--blue-600);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.4px;
}

.camera-resolution {
  font-size: 0.78rem;
  background: var(--blue-100);
  color: var(--blue-700);
  padding: 2px 10px;
  border-radius: 50px;
  font-weight: 600;
}

.camera-name {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--blue-900);
  margin-bottom: 8px;
  line-height: 1.4;
}

.camera-desc {
  font-size: 0.88rem;
  color: var(--gray-500);
  margin-bottom: 16px;
  flex: 1;
}

.camera-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--gray-200);
  padding-top: 14px;
}

.camera-price {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--blue-700);
}

.camera-price span {
  font-size: 0.85rem;
  font-weight: 400;
  color: var(--gray-500);
}

.camera-order {
  padding: 8px 16px;
  background: var(--zalo-blue);
  color: var(--white);
  border-radius: 50px;
  font-size: 0.85rem;
  font-weight: 600;
  transition: var(--transition);
}

.camera-order:hover {
  background: #0055d4;
}

.camera-cta {
  text-align: center;
  padding-top: 8px;
}

.camera-cta p {
  margin-bottom: 20px;
  font-size: 1.05rem;
  opacity: 0.9;
}

/* ===== About ===== */
.about {
  padding: 80px 0;
  background: var(--white);
}

.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}

.about-text h2 {
  font-size: 2rem;
  color: var(--blue-800);
  margin-bottom: 16px;
}

.about-text p {
  margin-bottom: 20px;
  font-size: 1.05rem;
}

.about-features {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.about-features li {
  font-size: 1rem;
  color: var(--gray-700);
}

.about-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.stat-card {
  background: linear-gradient(135deg, var(--blue-700), var(--blue-500));
  color: var(--white);
  border-radius: var(--radius);
  padding: 28px 16px;
  text-align: center;
}

.stat-number {
  display: block;
  font-size: 2rem;
  font-weight: 700;
}

.stat-label {
  font-size: 0.9rem;
  opacity: 0.85;
}

/* ===== Contact ===== */
.contact {
  padding: 80px 0;
}

.contact-card {
  background: linear-gradient(135deg, var(--blue-800), var(--blue-600));
  color: var(--white);
  border-radius: 20px;
  padding: 48px;
  text-align: center;
  box-shadow: var(--shadow-lg);
}

.contact-card h2 {
  font-size: 2rem;
  margin-bottom: 32px;
}

.contact-info {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 24px;
  margin-bottom: 36px;
  text-align: left;
}

.contact-item {
  display: flex;
  gap: 14px;
  align-items: flex-start;
}

.contact-icon {
  font-size: 1.5rem;
  flex-shrink: 0;
}

.contact-item strong {
  display: block;
  margin-bottom: 4px;
}

.contact-item p {
  opacity: 0.85;
  font-size: 0.95rem;
}

.contact-item a {
  color: var(--white);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.contact-item a:hover {
  opacity: 1;
}

.zalo-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
}

/* ===== Footer ===== */
.footer {
  background: var(--blue-900);
  color: rgba(255, 255, 255, 0.7);
  text-align: center;
  padding: 24px;
  font-size: 0.9rem;
}

/* ===== Nút Zalo nổi ===== */
.zalo-float {
  position: fixed;
  bottom: 28px;
  right: 28px;
  background: var(--zalo-blue);
  color: var(--white);
  border-radius: 50px;
  padding: 12px 20px;
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 600;
  font-size: 0.95rem;
  box-shadow: 0 4px 20px rgba(0, 104, 255, 0.5);
  z-index: 99;
  transition: var(--transition);
  animation: pulse 2s infinite;
}

.zalo-float:hover {
  background: #0055d4;
  transform: scale(1.05);
}

@keyframes pulse {
  0%, 100% { box-shadow: 0 4px 20px rgba(0, 104, 255, 0.5); }
  50% { box-shadow: 0 4px 30px rgba(0, 104, 255, 0.8); }
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .menu-toggle {
    display: flex;
  }

  .nav-menu {
    position: fixed;
    top: 68px;
    left: 0;
    right: 0;
    background: var(--white);
    flex-direction: column;
    padding: 16px;
    gap: 4px;
    box-shadow: var(--shadow);
    transform: translateY(-120%);
    opacity: 0;
    transition: var(--transition);
    pointer-events: none;
  }

  .nav-menu.open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: all;
  }

  .nav-link {
    width: 100%;
    text-align: center;
    padding: 12px;
  }

  .hero {
    padding: 60px 20px;
    min-height: auto;
  }

  .hero .btn {
    display: flex;
    width: 100%;
    justify-content: center;
    margin-bottom: 10px;
    margin-right: 0;
  }

  .camera-grid {
    grid-template-columns: 1fr;
  }

  .about-grid {
    grid-template-columns: 1fr;
  }

  .about-stats {
    grid-template-columns: repeat(3, 1fr);
  }

  .contact-card {
    padding: 32px 20px;
  }

  .zalo-float span {
    display: none;
  }

  .zalo-float {
    padding: 14px;
    border-radius: 50%;
  }
}

@media (max-width: 480px) {
  .about-stats {
    grid-template-columns: 1fr;
  }
}