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

body{
    font-family:Arial, Helvetica, sans-serif;
    line-height:1.8;
    color:#333;
    background:#fafafa;
}

.container{
    width:90%;
    max-width:1100px;
    margin:auto;
}

header{
    background:#0d9488;
    color:#fff;
    padding:20px 0;
    position:sticky;
    top:0;
}

header .container{
    display:flex;
    justify-content:space-between;
    align-items:center;
}

nav a{
    color:white;
    text-decoration:none;
    margin-left:20px;
    font-weight:bold;
}

nav a:hover{
    color:#ffe082;
}

.hero{
    background:linear-gradient(rgba(0,0,0,.55),rgba(0,0,0,.55)),
    url('https://images.unsplash.com/photo-1544551763-46a013bb70d5?auto=format&fit=crop&w=1500&q=80');
    background-size:cover;
    background-position:center;
    color:white;
    text-align:center;
    padding:120px 20px;
}

.hero h2{
    font-size:45px;
    margin-bottom:20px;
}

.hero p{
    font-size:20px;
    margin-bottom:30px;
}

.btn{
    display:inline-block;
    background:#22c55e;
    color:white;
    padding:14px 30px;
    border-radius:30px;
    text-decoration:none;
    font-weight:bold;
}

.btn:hover{
    background:#16a34a;
}

section{
    padding:70px 0;
}

.gray{
    background:#f2f2f2;
}

.cards{
    display:grid;
    grid-template-columns:repeat(3,1fr);
    gap:25px;
    margin-top:30px;
}

.card{
    background:white;
    padding:30px;
    border-radius:10px;
    box-shadow:0 5px 20px rgba(0,0,0,.08);
    transition:.3s;
}

.card:hover{
    transform:translateY(-8px);
}

article{
    background:white;
    padding:25px;
    margin-top:25px;
    border-left:5px solid #0d9488;
    box-shadow:0 3px 15px rgba(0,0,0,.08);
}

footer{
    background:#0d9488;
    color:white;
    text-align:center;
    padding:25px;
}

@media(max-width:768px){

header .container{
    flex-direction:column;
}

nav{
    margin-top:15px;
}

nav a{
    display:inline-block;
    margin:10px;
}

.hero h2{
    font-size:32px;
}

.hero p{
    font-size:17px;
}

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

}