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

:root{
--red:#d40000;
--red-light:#ff2d2d;
--bg:#050505;
--card:#101010;
--text:#ffffff;
--gray:#9a9a9a;
}

body{
background:var(--bg);
color:var(--text);
min-height:100vh;
overflow-x:hidden;
}

body::before{
content:"";
position:fixed;
top:-250px;
right:-250px;
width:600px;
height:600px;
background:
radial-gradient(
circle,
rgba(212,0,0,.25),
transparent 70%
);
z-index:-1;
}

/* Header */

header{
width:92%;
height:80px;
margin:20px auto;
display:flex;
align-items:center;
justify-content:space-between;
padding:0 25px;
background:#111;
border-radius:18px;
border:1px solid rgba(255,255,255,.05);
}

.logo{
font-size:24px;
font-weight:800;
color:var(--red-light);
}

.back-btn{
text-decoration:none;
color:#fff;
padding:10px 18px;
border-radius:12px;
background:#191919;
transition:.3s;
}

.back-btn:hover{
background:var(--red);
}

/* Product */

.product-container{
width:92%;
margin:40px auto;
display:grid;
grid-template-columns:
1fr 1fr;
gap:40px;
align-items:center;
}

.product-image{
background:#111;
padding:20px;
border-radius:25px;
border:1px solid rgba(255,255,255,.05);
}

.product-image img{
width:100%;
border-radius:20px;
display:block;
}

.product-info{
background:#111;
padding:35px;
border-radius:25px;
border:1px solid rgba(255,255,255,.05);
}

.product-info h1{
font-size:34px;
margin-bottom:20px;
}

.price{
font-size:38px;
font-weight:800;
color:var(--red-light);
margin-bottom:20px;
}

.description{
line-height:1.9;
color:#bbb;
margin-bottom:25px;
}

.features{
list-style:none;
margin-bottom:30px;
}

.features li{
padding:10px 0;
border-bottom:1px solid rgba(255,255,255,.05);
}

.buy-btn{
display:block;
text-align:center;
padding:16px;
text-decoration:none;
color:#fff;
font-weight:700;
border-radius:16px;
background:
linear-gradient(
90deg,
#a00000,
#ff0000
);
transition:.3s;
}

.buy-btn:hover{
transform:translateY(-2px);
box-shadow:
0 0 25px rgba(255,0,0,.35);
}

/* Related */

.related-products{
width:92%;
margin:70px auto;
}

.related-products h2{
margin-bottom:25px;
}

.related-grid{
display:grid;
grid-template-columns:
repeat(auto-fit,minmax(250px,1fr));
gap:25px;
}

.related-card{
text-decoration:none;
background:#111;
border-radius:20px;
overflow:hidden;
border:1px solid rgba(255,255,255,.05);
transition:.3s;
}

.related-card:hover{
transform:translateY(-6px);
box-shadow:
0 0 25px rgba(255,0,0,.25);
}

.related-card img{
width:100%;
height:220px;
object-fit:cover;
}

.related-card h3{
padding:18px;
color:#fff;
text-align:center;
}

footer{
margin-top:60px;
padding:30px;
text-align:center;
color:#777;
border-top:1px solid rgba(255,255,255,.05);
}

/* Mobile */

@media(max-width:900px){

.product-container{
grid-template-columns:1fr;
}

.product-info h1{
font-size:28px;
}

.price{
font-size:30px;
}

.logo{
font-size:20px;
}

header{
padding:0 15px;
}

}