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

html {
    scroll-behavior: smooth;
}

body{
background:#f5f7fb;
behavior: smooth;
}

header{
display:flex;
justify-content:space-between;
align-items:center;
padding:15px 8%;
background: #0F172A;
color:#fff;
position:sticky;
top:0;
z-index: 9999;
}

.logo{
font-size:28px;
font-weight:bold;
}

nav{
display:flex;
gap:20px;
}

nav a{
color:white;
text-decoration:none;
font-weight:bold;
}

#menu{
display:none;
}

.hamburger{
display:none;
font-size:28px;
cursor:pointer;
}

.hero{
text-align:center;
padding:70px 20px;
background:linear-gradient(135deg,#1565c0,#0A2540);
color:white;
}

.hero h1{
font-size:45px;
margin-bottom:15px;
}

.courses{
display:grid;
grid-template-columns:repeat(auto-fit,minmax(280px,1fr));
gap:30px;
padding:60px 8%;
}

.card{
background:darkblue;
border-radius:15px;
overflow:hidden;
box-shadow:0 5px 20px rgba(0,0,0,.1);
transition:.4s;

}

.card:hover{
transform:translateY(-10px);
}

.card img{
width:100%;
height:200px;
object-fit:cover;
}

.card h3{
padding:15px;
color: blue;
}

.card p{
padding:0 15px 20px;
color: white;
}

.card a{
display:block;
margin:20px;
text-align:center;
background:#1565c0;
color:white;
padding:12px;
border-radius:8px;
text-decoration:none;
}

.card a:hover{
background:#0d47a1;
}



/* Previous Button */
.previous-btn {
    display: inline-block;
    background: #111;
    color: white;
    text-decoration: none;
    padding: 14px 25px;
    border-radius: 7px;
    transition: 0.3s;
}

.previous-btn:hover {
    background: #333;
}

.previous-section {
    text-align: left;
}
/*NEXT LESSON */
.next-btn {
    display: inline-block;
    background: #111;
    color: white;
    text-decoration: none;
    padding: 14px 25px;
    border-radius: 7px;
}

.next-btn:hover {
    background: #333;
}

.next-section {
    text-align: right;
}




footer{
background:#222;
color:white;
text-align:center;
padding:40px 20px;
margin-top:40px;
}

@media(max-width:768px){

.hamburger{
display:block;
}

nav{
display:none;
position:absolute;
top:70px;
left:0;
width:100%;
background:#0d47a1;
flex-direction:column;
}

nav a{
padding:15px;
text-align:center;
}

#menu:checked~nav{
display:flex;
}

.hero h1{
font-size:35px;
}



    .next-section {
        text-align: center;
        margin-bottom: 30px;
    }



}