*{
box-sizing:border-box;
margin:0;
padding:0;
}

body{
font-family: "Segoe UI", Arial, sans-serif;
background: linear-gradient(135deg,#21c4cf,#2575fc);
min-height:100vh;
display:flex;
justify-content:center;
color:#333;
padding:30px;
}

.container{
max-width:1100px;
width:100%;
}

h1{
text-align:center;
color:white;
margin-bottom:30px;
font-size:2.2rem;
letter-spacing:1px;
}

.grid{
display:grid;
gap:30px;
}

.video-container{
position:relative;
width:100%;
padding-top:56.25%;
border-radius:15px;
overflow:hidden;
height:min-content;
box-shadow:0 10px 25px rgba(0,0,0,0.3);
}

.video-container video{
position:absolute;
top:0;
left:0;
width:100%;
}

.explanation{
background:rgba(255,255,255,0.85);
backdrop-filter:blur(10px);
padding:25px;
border-radius:15px;
box-shadow:0 8px 20px rgba(0,0,0,0.2);
}

.explanation h2{
margin-bottom:10px;
color:#444;
}

.explanation p{
margin-bottom:12px;
line-height:1.6;
}

ul{
margin-top:10px;
padding-left:20px;
}

li{
margin-bottom:6px;
}

/* liens stylés */

a{
color:#2575fc;
text-decoration:none;
font-weight:600;
position:relative;
}

a::after{
content:"";
position:absolute;
width:0;
height:2px;
bottom:-3px;
left:0;
background:#2575fc;
transition:0.3s;
}

a:hover::after{
width:100%;
}

/* bouton optionnel */

.button{
display:inline-block;
margin-top:10px;
padding:10px 18px;
background:#2575fc;
color:white;
border-radius:8px;
font-size:0.9rem;
transition:0.25s;
}

.button:hover{
background:#1b5ed8;
transform:translateY(-2px);
}

/* responsive desktop */

@media (min-width:768px){

.grid{
grid-template-columns:1.2fr 1fr;
}

}