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

/* ========== PRODUCT CARDS ========== */
.gpu-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;
}

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

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

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

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

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

body.light .gpu-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: space-between;
  align-items: center;
  max-width: 500px;
  margin: 3rem auto;
  gap: 2rem;
}

.prev,
.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;
}

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

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

body.light .prev:hover,
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) {
  .gpu-card {
    width: 180px;
    height: 180px;
  }
  .gpu-card h3 {
    font-size: 1rem;
  }
  .gpu-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);
}