* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: Arial, Helvetica, sans-serif;
}

body {
  background: #f5f6fa;
  color: #222;
}

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

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

.container {
  width: 90%;
  max-width: 1200px;
  margin: auto;
}

/* Header */
header {
  background: #111827;
  color: #fff;
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.navbar {
  height: 70px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.logo {
  font-size: 24px;
  font-weight: bold;
  color: #38bdf8;
}

.logo span {
  color: #facc15;
}

.nav-links {
  display: flex;
  gap: 24px;
  align-items: center;
}

.nav-links a {
  font-size: 15px;
  transition: 0.3s;
}

.nav-links a:hover {
  color: #38bdf8;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.btn {
  border: none;
  outline: none;
  padding: 10px 16px;
  border-radius: 8px;
  background: #38bdf8;
  color: #111827;
  font-weight: bold;
  cursor: pointer;
  transition: 0.3s;
}

.btn:hover {
  transform: translateY(-2px);
  background: #0ea5e9;
}

.btn-dark {
  background: #111827;
  color: #fff;
}

.btn-outline {
  background: transparent;
  color: #fff;
  border: 1px solid #38bdf8;
}

.cart-btn {
  position: relative;
}

.cart-count {
  position: absolute;
  top: -8px;
  right: -8px;
  background: #ef4444;
  color: #fff;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
}

.menu-toggle {
  display: none;
  font-size: 26px;
  cursor: pointer;
}

/* Banner */
.hero {
  min-height: 520px;
  background:
    linear-gradient(120deg, rgba(17, 24, 39, 0.92), rgba(14, 165, 233, 0.68)),
    url("https://images.unsplash.com/photo-1542291026-7eec264c27ff?auto=format&fit=crop&w=1600&q=80");
  background-size: cover;
  background-position: center;
  color: #fff;
  display: flex;
  align-items: center;
}

.hero-content {
  max-width: 650px;
  padding: 60px 0;
}

.hero-content h1 {
  font-size: 48px;
  line-height: 1.15;
  margin-bottom: 18px;
}

.hero-content p {
  font-size: 18px;
  line-height: 1.6;
  margin-bottom: 26px;
  color: #e5e7eb;
}

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

/* Section chung */
.section {
  padding: 60px 0;
}

.section-title {
  text-align: center;
  margin-bottom: 34px;
}

.section-title h2 {
  font-size: 32px;
  margin-bottom: 8px;
}

.section-title p {
  color: #6b7280;
}

/* Feature */
.features {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  margin-top: -60px;
  position: relative;
  z-index: 2;
}

.feature-card {
  background: #fff;
  padding: 24px;
  text-align: center;
  border-radius: 16px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
  transition: 0.3s;
}

.feature-card:hover {
  transform: translateY(-8px);
}

.feature-card .icon {
  font-size: 34px;
  margin-bottom: 12px;
}

.feature-card h3 {
  margin-bottom: 8px;
  font-size: 18px;
}

.feature-card p {
  color: #6b7280;
  font-size: 14px;
  line-height: 1.5;
}

/* Filter */
.filters {
  background: #fff;
  padding: 20px;
  border-radius: 16px;
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.06);
  margin-bottom: 28px;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr 1fr;
  gap: 14px;
}

.filters input,
.filters select,
.checkout-form input,
.checkout-form textarea,
.auth-box input {
  width: 100%;
  padding: 12px;
  border: 1px solid #d1d5db;
  border-radius: 8px;
  outline: none;
  font-size: 14px;
}

.filters input:focus,
.filters select:focus,
.checkout-form input:focus,
.checkout-form textarea:focus,
.auth-box input:focus {
  border-color: #38bdf8;
}

/* Product */
.product-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.product-card {
  background: #fff;
  border-radius: 16px;
  overflow: hidden;
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.07);
  transition: 0.3s;
  position: relative;
}

.product-card:hover {
  transform: translateY(-8px);
  box-shadow: 0 14px 30px rgba(0, 0, 0, 0.12);
}

.product-img {
  height: 210px;
  overflow: hidden;
  background: #e5e7eb;
}

.product-img img {
  height: 100%;
  object-fit: cover;
  transition: 0.4s;
}

.product-card:hover img {
  transform: scale(1.08);
}

.badge {
  position: absolute;
  top: 12px;
  left: 12px;
  background: #facc15;
  padding: 6px 10px;
  border-radius: 20px;
  font-size: 12px;
  font-weight: bold;
  z-index: 2;
}

.product-info {
  padding: 18px;
}

.product-info h3 {
  font-size: 18px;
  margin-bottom: 8px;
}

.product-meta {
  display: flex;
  justify-content: space-between;
  color: #6b7280;
  font-size: 14px;
  margin-bottom: 10px;
}

.price {
  color: #ef4444;
  font-size: 20px;
  font-weight: bold;
  margin-bottom: 14px;
}

.product-actions {
  display: flex;
  gap: 8px;
}

.product-actions .btn {
  flex: 1;
  font-size: 13px;
  padding: 10px;
}

/* About */
.about-box {
  background: #111827;
  color: #fff;
  border-radius: 20px;
  padding: 36px;
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 30px;
  align-items: center;
}

.about-box h2 {
  font-size: 30px;
  margin-bottom: 14px;
}

.about-box p {
  color: #d1d5db;
  line-height: 1.7;
  margin-bottom: 12px;
}

.about-list {
  display: grid;
  gap: 12px;
}

.about-item {
  background: rgba(255, 255, 255, 0.08);
  padding: 14px;
  border-radius: 12px;
}

/* Checkout */
.checkout {
  background: #fff;
  border-radius: 20px;
  padding: 28px;
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.06);
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 28px;
}

.checkout-form {
  display: grid;
  gap: 14px;
}

.checkout-form textarea {
  height: 100px;
  resize: none;
}

.order-summary {
  background: #f9fafb;
  padding: 20px;
  border-radius: 16px;
}

.order-summary h3 {
  margin-bottom: 16px;
}

.summary-row {
  display: flex;
  justify-content: space-between;
  margin-bottom: 12px;
  color: #374151;
}

.summary-row.total {
  border-top: 1px solid #d1d5db;
  padding-top: 12px;
  font-weight: bold;
  font-size: 20px;
  color: #ef4444;
}

.note {
  color: #6b7280;
  font-size: 14px;
  margin-top: 14px;
  line-height: 1.5;
}

/* Footer */
footer {
  background: #111827;
  color: #fff;
  padding: 36px 0;
  text-align: center;
}

footer p {
  color: #d1d5db;
  margin-top: 8px;
}

/* Cart và Modal */
.cart-drawer,
.modal {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.55);
  z-index: 2000;
  display: none;
}

.cart-drawer.active,
.modal.active {
  display: block;
}

.cart-panel {
  width: 390px;
  max-width: 92%;
  height: 100%;
  background: #fff;
  margin-left: auto;
  padding: 22px;
  overflow-y: auto;
  animation: slideIn 0.25s ease;
}

@keyframes slideIn {
  from {
    transform: translateX(100%);
  }

  to {
    transform: translateX(0);
  }
}

.cart-header,
.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 18px;
}

.close-btn {
  border: none;
  background: #ef4444;
  color: #fff;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  cursor: pointer;
  font-weight: bold;
}

.cart-item {
  display: grid;
  grid-template-columns: 70px 1fr;
  gap: 12px;
  padding: 12px 0;
  border-bottom: 1px solid #e5e7eb;
}

.cart-item img {
  height: 70px;
  object-fit: cover;
  border-radius: 10px;
}

.cart-item h4 {
  font-size: 15px;
  margin-bottom: 5px;
}

.cart-item p {
  color: #ef4444;
  font-weight: bold;
  margin-bottom: 8px;
}

.qty-box {
  display: flex;
  align-items: center;
  gap: 8px;
}

.qty-box button,
.remove-btn {
  border: none;
  background: #e5e7eb;
  padding: 5px 8px;
  border-radius: 6px;
  cursor: pointer;
}

.remove-btn {
  color: #ef4444;
  margin-left: 4px;
}

.cart-total {
  margin-top: 20px;
  font-size: 20px;
  font-weight: bold;
  display: flex;
  justify-content: space-between;
}

.checkout-link {
  width: 100%;
  margin-top: 18px;
  display: block;
  text-align: center;
}

.modal-content {
  width: 760px;
  max-width: 92%;
  max-height: 90vh;
  overflow-y: auto;
  background: #fff;
  margin: 5vh auto;
  padding: 24px;
  border-radius: 18px;
  animation: fadeIn 0.25s ease;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: scale(0.95);
  }

  to {
    opacity: 1;
    transform: scale(1);
  }
}

/* Chi tiết sản phẩm */
.detail-box {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  align-items: center;
}

.detail-box img {
  height: 330px;
  object-fit: cover;
  border-radius: 16px;
}

.detail-info h2 {
  font-size: 28px;
  margin-bottom: 10px;
}

.detail-info p {
  line-height: 1.7;
  color: #4b5563;
  margin-bottom: 12px;
}

.size-list {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin: 12px 0 18px;
}

.size-list span {
  border: 1px solid #d1d5db;
  padding: 8px 12px;
  border-radius: 8px;
  cursor: pointer;
  transition: 0.3s;
}

.size-list span:hover {
  background: #38bdf8;
  border-color: #38bdf8;
}

/* Auth */
.auth-box {
  max-width: 420px;
  margin: auto;
}

.auth-tabs {
  display: flex;
  gap: 10px;
  margin-bottom: 18px;
}

.auth-tabs button {
  flex: 1;
}

.auth-form {
  display: none;
  gap: 12px;
}

.auth-form.active {
  display: grid;
}

.empty-text {
  color: #6b7280;
  text-align: center;
  padding: 20px 0;
}

/* Responsive */
@media (max-width: 992px) {
  .features,
  .product-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

  .about-box,
  .checkout,
  .detail-box {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .menu-toggle {
    display: block;
  }

  .nav-links {
    position: absolute;
    top: 70px;
    left: 0;
    width: 100%;
    background: #111827;
    flex-direction: column;
    padding: 20px;
    display: none;
  }

  .nav-links.active {
    display: flex;
  }

  .nav-actions .btn-outline {
    display: none;
  }

  .hero-content h1 {
    font-size: 34px;
  }

  .hero-content p {
    font-size: 16px;
  }

  .features,
  .product-grid,
  .filters {
    grid-template-columns: 1fr;
  }

  .feature-card {
    padding: 20px;
  }

  .section {
    padding: 42px 0;
  }

  .modal-content {
    margin: 3vh auto;
  }
}