* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: Arial, Helvetica, sans-serif;
  }
  
  body {
    background: #0b0f1a;   /* nền tối web game */
    color: #e5e7eb;
  }
  
  /* HEADER */
  .header {
    background: #020617;
    padding: 16px 32px;
    display: flex;
    justify-content: space-between;
    align-items: center;
  }
  
  .header-left {
    display: flex;
    align-items: center;
    gap: 32px;
  }
  
  /* LOGO */
  .logo {
    font-size: 32px;
    font-weight: 800;
    letter-spacing: 2px;
    color: #3b82f6;
    text-shadow: 0 0 12px rgba(59,130,246,0.8);
  }
  
  /* MENU */
  nav a {
    color: #ffffff;
    margin-right: 18px;
    text-decoration: none;
  }
  
  nav a:hover {
    color: #93c5fd;
  }
  
  /* SEARCH + SORT */
  .header-right {
    display: flex;
    gap: 12px;
  }
  
  .header-right input,
  .header-right select {
    padding: 10px 14px;
    border-radius: 8px;
    border: none;
    outline: none;
  }
  
  /* BANNER */
  .banner {
    display: flex;
    justify-content: center; /* căn giữa */
    margin: 40px 0;
  }
  
  .banner img {
    max-width: 1000px;   /* khung nhỏ lại */
    width: 100%;
    height: auto;
    border-radius: 16px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.6);
  }
  
  
  /* LAYOUT */
  .container {
    max-width: 1200px;
    margin: 50px auto;
    padding: 0 16px;
  }
  
  .section-title {
    color: #fff;
    margin-bottom: 24px;
    font-size: 24px;
  }
  
  /* PRODUCTS */
  .products {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 28px;
  }
  
  .product {
    background: #ffffff;     /* khung trắng */
    color: #111827;
    border-radius: 14px;
    padding: 16px;
    box-shadow: 0 15px 30px rgba(0,0,0,0.4);
    transition: 0.25s;
  }
  
  .product:hover {
    transform: translateY(-6px);
  }
  
  .product img {
    width: 100%;
    height: 170px;
    object-fit: cover;
    border-radius: 10px;
  }
  
  .product h3 {
    margin: 12px 0 6px;
  }
  
  .product p {
    font-size: 14px;
    color: #4b5563;
  }
  
  .price {
    margin: 12px 0;
    font-size: 18px;
    font-weight: bold;
    color: #dc2626;
  }
  
  /* BUTTON */
  .product button {
    width: 100%;
    padding: 12px;
    border: none;
    border-radius: 10px;
    background: #2563eb;
    color: #fff;
    cursor: pointer;
    transition: 0.25s;
  }
  
  .product button:hover {
    transform: scale(1.08);
    box-shadow: 0 10px 25px rgba(37,99,235,0.5);
  }

  .header-right {
    display: flex;
    align-items: center;
    gap: 16px;
  }
  
  /* SEARCH */
  .header-right input {
    padding: 10px 14px;
    border-radius: 8px;
    border: none;
    outline: none;
  }
  
  /* CART */
  .cart {
    position: relative;
    font-size: 30px;
    cursor: pointer;
    color: #3b82f6;
    text-shadow: 0 0 10px rgba(59,130,246,0.9);
    transition: 0.2s;
  }
  
  .cart:hover {
    transform: scale(1.15);
  }
  
  /* SỐ LƯỢNG */
  .cart span {
    position: absolute;
    top: -8px;
    right: -10px;
    background: red;
    color: #fff;
    font-size: 12px;
    font-weight: bold;
    padding: 3px 7px;
    border-radius: 50%;
  }
  
  /* HIỆU ỨNG NẢY */
  .pop {
    animation: pop 0.2s ease;
  }
  
  @keyframes pop {
    0% { transform: scale(1); }
    50% { transform: scale(1.4); }
    100% { transform: scale(1); }
  }
  

  
  
  /* FOOTER */
  footer {
    background: #020617;
    color: #9ca3af;
    text-align: center;
    padding: 22px;
    margin-top: 50px;
  }
  
  .section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
  }
  
  .sort {
    padding: 10px 14px;
    border-radius: 8px;
    border: none;
    outline: none;
    font-size: 14px;
  }