* {
    font-family: 'Inter';
    margin: 0;
    padding: 0;
    box-sizing: border-box;
  }

  body {
    background-color: #1e293b;
    padding: 20px;
  }

  body.light {
    background: linear-gradient(200deg, #858ea0, #4b5360);
    color: #0f172a;
  }

  /* ========== HEADER ========== */
  header {
    background-color: #3b82f6;
    padding: 20px;
    border-radius: 15px;
    margin-bottom: 40px;
    gap: 1rem;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    display: flex;
    
  }

  header h1 {
    color: #cbd5e1;
    font-size: 2.5rem;
    margin: 0;
  }

  header h1 i {
    margin-right: 10px;
  }

  header p {
    color: #cbd5e1;
    font-size: 1.5rem;
    margin: 0;
  }

  body.light header {
    background-color: #94a3b8;
  }

  body.light header h1 {
    color: #1e293b;
  }

  body.light header p {
    color: #334155;
  }

  /* ========== THEME BUTTON ========== */
  .theme-btn {
    background: #334155;
    border: none;
    font-size: 1.3rem;
    padding: 0.5rem 1rem;
    border-radius: 40px;
    cursor: pointer;
    transition: 0.4s;
  }

  .theme-btn:hover {
    background-color: #2563eb;
    transform: translateY(-3px);
  }

  body.light .theme-btn {
    background-color: #b8c7d9;
    color: #1e293b;
    border: 1px solid #e2e8f0;
  }

  body.light .theme-btn:hover {
    background-color: #475569;
    color: white;
  }

  /* ========== PRODUCT CONTAINER ========== */
  .cpu-container {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 30px;
    max-width: 1200px;
    margin: 0 auto;
  }

  /* ========== PRODUCT CARDS ========== */
  .cpu-card {
    width: 250px;
    height: 250px;
    background-color: #0f172a;
    border-radius: 20px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.3);
    padding: 20px;
  }

  .cpu-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 24px rgba(59, 130, 246, 0.2);
    border: 1px solid #3b82f6;
  }

  .cpu-card h3 {
    color: #f8fafc;
    font-size: 1.3rem;
    margin-bottom: 10px;
  }

  .product-specs {
    font-size: 0.75rem;
    color: #94a3b8;
    margin-bottom: 0.8rem;
  }

  .cpu-card .price {
    color: #3b82f6;
    font-size: 1.2rem;
    font-weight: bold;
    margin: 15px 0;
  }

  body.light .cpu-card {
    background: #cbd5e1;
    border-color: #475569;
  }

  body.light .cpu-card h3 {
    color: #0f172a;
  }

  body.light .product-specs {
    color: #1e293b;
  }

  body.light .price {
    color: #1e293b;
  }

  /* ========== BUY BUTTON ========== */
  .buy-btn {
    background-color: #3b82f6;
    color: #f8fafc;
    border: none;
    padding: 10px 24px;
    border-radius: 30px;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: bold;
  }

  .buy-btn:hover {
    background-color: #2563eb;
    transform: translateY(-3px);
  }

  body.light .buy-btn {
    background: linear-gradient(135deg, #aac3e3, #636b74);
  }

  body.light .buy-btn:hover {
    background: linear-gradient(135deg, #b0bed0, #868e98);
    transform: translateY(-5px);
  }

  /* ========== NAVIGATION BUTTONS ========== */
  .nav {
    display: flex;
    justify-content: center;
    align-items: center;
    max-width: 500px;
    margin: 3rem auto;
    gap: 2rem;
  }

  .next {
    background: #0f172a;
    color: #cbd5e1;
    text-decoration: none;
    padding: 0.8rem 1.5rem;
    border-radius: 40px;
    font-weight: 600;
    transition: all 0.4s ease;
    display: flex;
    align-items: center;
    gap: 8px;
  }

  .next:hover {
    background: #3b82f6;
    color: white;
    transform: translateY(-4px);
  }

  body.light .next {
    background: #868b91;
    color: #1e293b;
  }

  body.light .next:hover {
    background-color: #b1c5e1;
  }

  /* ========== BACK BUTTON ========== */
  .back-container {
    text-align: center;
    margin-top: 50px;
  }

  .back-btn {
    display: inline-block;
    background-color: transparent;
    border: 2px solid #3b82f6;
    color: #3b82f6;
    padding: 10px 25px;
    border-radius: 40px;
    text-decoration: none;
    font-weight: bold;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.3);
  }

  .back-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 12px 24px rgba(59, 130, 246, 0.2);
    border: 1px solid #3b82f6;
  }

  body.light .back-btn {
    border: 1px solid #1e293b;
    background-color: #94a3b8;
    color: #0f172a;
  }

  body.light .back-btn:hover {
    background-color: #c9cfd7;
  }

  /* ========== RESPONSIVE ========== */
  @media (max-width: 600px) {
    .cpu-card {
      width: 180px;
      height: 180px;
    }
    .cpu-card h3 {
      font-size: 1rem;
    }
    .cpu-card .price {
      font-size: 0.9rem;
    }
    .buy-btn {
      padding: 6px 16px;
      font-size: 0.8rem;
    }
    .nav {
      flex-direction: column;
      gap: 1rem;
    }
  }

/* ========== انیمیشن ========== */
.animate-fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.5s ease, transform 0.5s ease;
}

.animate-fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}