:root{
    --primary:#3498db;
    --secondary:#2c3e50;
}
*{box-sizing:border-box;margin:0;padding:0}
body{
    font-family:'Segoe UI',Tahoma,sans-serif;
    background:linear-gradient(135deg,#e8f0fe 0%,#d0e1f9 100%);
    min-height:100vh;
    display:flex;
    flex-direction:column;
}
header{
    background:linear-gradient(135deg,var(--primary) 0%,var(--secondary) 100%);
    color:#fff;
    text-align:center;
    padding:35px 20px;
    box-shadow:0 4px 10px rgba(0,0,0,.1);
    display:flex;
    align-items:flex-start;
    justify-content:space-between;
    position:relative;
}
.logo-container{
    position:absolute;
    top:20px;
    left:20px;
}
header .logo{
    width:180px;
    height:auto;
}
.header-center{
    flex:1;
    display:flex;
    flex-direction:column;
    align-items:center;
    gap:15px;
}
header .header-text{
    text-align:center;
}
header .header-text h1{
    margin-bottom:6px;
    font-weight:bold;
    letter-spacing:1px;
    font-size:2.4em;
    color:#fff;
}
header .header-text h2{
    color:#fff;
    font-weight:bold;
}

nav{
    background:var(--secondary);
    text-align:center;
    padding:10px 0;
    box-shadow:0 2px 6px rgba(0,0,0,.08);
}
nav a{
    color:#fff;
    margin:0 15px;
    text-decoration:none;
    font-weight:600;
    transition:opacity .2s;
}
nav a:hover{opacity:.8}
main{
    flex:1;
    display:flex;
    align-items:center;
    justify-content:center;
    padding:40px 20px;
}
.cards{
    display:flex;
    flex-wrap:wrap;
    gap:30px;
    max-width:1100px;
    justify-content:center;
}
.card{
    background:#fff;
    width:260px;
    border-radius:14px;
    padding:35px 25px;
    text-align:center;
    text-decoration:none;
    color:var(--secondary);
    font-weight:600;
    font-size:1.2rem;
    box-shadow:0 10px 25px rgba(0,0,0,.08);
    transition:transform .25s ease,box-shadow .25s ease;
}
.card:hover{
    transform:translateY(-8px);
    box-shadow:0 15px 35px rgba(0,0,0,.15);
}
footer{
    text-align:center;
    padding:15px 10px;
    font-size:.9em;
    color:#2c3e50;
    margin-top:auto;
}

/* Responsive */
@media(max-width:768px){
    header{
        flex-direction:column;
        padding:25px 15px;
        gap:15px;
        align-items:center;
        text-align:center;
    }
    .logo-container{
        position:static;
        margin-bottom:10px;
        display:flex;
        justify-content:center;
    }
    header .logo{width:135px;}
    .header-center{gap:10px;width:100%;}
    header .header-text h1{font-size:1.8em;}
    header .header-text h2{font-size:1rem;}
}
@media(max-width:480px){
    header .logo{width:105px;}
    header .header-text h1{font-size:1.5em;}
    header .header-text h2{font-size:.9rem;}
}