@media (max-width: 1024px) {
  .intro {
    padding: 80px 20px;
  }
  .intro h1 {
    font-size: 2.8rem;
  }
  .intro p {
    font-size: 1.1rem;
  }
  .call-to-action h2 {
    font-size: 1.9rem;
  }
  .call-to-action .btn {
    padding: 10px 28px;
    font-size: 16px;
  }
  /* end of 1024 */
}

@media (max-width: 768px) {
  .navbar .navbar-collapse {
    text-align: center;
  }

  .navbar .navbar-nav {
    flex-direction: column;
    margin-top: 10px;
  }

  .navbar .navbar-nav .nav-item {
    margin-bottom: 10px;
  }

  .navbar .d-flex {
    justify-content: center;
    margin-top: 10px;
  }

  .navbar .search-bar input {
    width: 200px;
  }

  .intro h1 {
    font-size: 2.5rem;
  }

  .intro p {
    font-size: 1rem;
  }

  .features {
    padding: 40px 10px;
  }

  .feature i {
    font-size: 35px;
  }

  .feature h3 {
    font-size: 1.3rem;
  }

  .feature p {
    font-size: 0.9rem;
  }

  .call-to-action h2 {
    font-size: 1.8rem;
  }

  .call-to-action .btn {
    padding: 10px 25px;
    font-size: 16px;
  }

  .product-card {
    width: 180px;
  }

  .product-card img {
    height: 130px;
  }

  .product-card .product-title {
    font-size: 14px;
  }

  .product-card .product-price {
    font-size: 12px;
  }
  #about h2 {
    font-size: 2rem;
  }

  .image-wrapper {
    height: 180px;
  }

  #testimonials h2 {
    font-size: 2rem;
  }

  .card {
    padding: 20px;
  }

  .testimonial-avatar img {
    width: 80px;
    height: 80px;
  }

  .card-text {
    font-size: 1rem;
  }
  /* end 768 */
}

/* ********************************* */
@media (max-width: 576px) {
  .navbar .navbar-brand {
    font-size: 20px;
  }

  .navbar .d-flex .search-bar input {
    width: 150px;
  }

  .navbar .fa-shopping-cart,
  .navbar .fa-search {
    font-size: 20px;
  }

  .hero-section {
    height: auto;
    padding: 40px 0;
  }

  .intro h1 {
    font-size: 2rem;
  }

  .intro p {
    font-size: 0.9rem;
  }

  .call-to-action h2 {
    font-size: 1.5rem;
  }

  .call-to-action .btn {
    padding: 8px 20px;
    font-size: 14px;
  }

  .features .col-12 {
    margin-bottom: 20px;
  }

  .product-card {
    width: 160px;
  }

  .product-card img {
    height: 110px;
  }

  .product-card .product-title {
    font-size: 12px;
  }

  .product-card .product-price {
    font-size: 10px;
  }
  .image-wrapper {
    height: 150px;
  }

  .card-title {
    font-size: 1.1rem;
  }

  .card-text {
    font-size: 0.85rem;
  }
  #testimonials h2 {
    font-size: 1.8rem;
  }

  .card {
    padding: 15px;
  }

  .testimonial-avatar img {
    width: 70px;
    height: 70px;
  }

  .card-text {
    font-size: 0.95rem;
  }
  /* end 576 */
}

/* max-width is 400px */
@media (max-width: 400px) {
  .intro h1 {
    font-size: 1.8rem;
  }

  .intro p {
    font-size: 0.8rem;
  }

  .feature i {
    font-size: 30px;
  }

  .feature h3 {
    font-size: 1.2rem;
  }

  .feature p {
    font-size: 0.8rem;
  }

  .call-to-action h2 {
    font-size: 1.3rem;
  }

  .call-to-action .btn {
    padding: 8px 18px;
    font-size: 12px;
  }
}