*{
margin:0;
padding:0;
box-sizing:border-box;
font-family:system-ui;
}

body{
background:#f5f7fb;
color:#222;
}

/* цветные заголовки */

h1{
color:#2563eb;
}

h3{
color:#16a34a;
}

h4{
color:#2563eb;
}

/* header */

header{
position:fixed;
top:0;
width:100%;
display:flex;
justify-content:center;
align-items:center;
padding:18px 30px;
background:#111;
color:white;
z-index:1000;
}

.logo{
position:absolute;
left:30px;
font-size:22px;
font-weight:bold;
}

.nav{
display:flex;
gap:35px;
}

.nav a{
color:white;
text-decoration:none;
font-size:16px;
}

.nav a:hover{
color:#00aaff;
}

/* burger */

.burger{
display:none;
flex-direction:column;
gap:6px;
cursor:pointer;
position:absolute;
right:30px;
}

.burger span{
width:28px;
height:3px;
background:#00aaff;
transition:.3s;
}

.burger.active span:nth-child(1){
transform:rotate(45deg) translate(6px,6px);
}

.burger.active span:nth-child(2){
opacity:0;
}

.burger.active span:nth-child(3){
transform:rotate(-45deg) translate(6px,-6px);
}

/* mobile menu */

.nav.mobile{
position:fixed;
top:0;
right:-300px;
width:300px;
height:100%;
flex-direction:column;
justify-content:center;
align-items:center;
gap:30px;
background:rgba(255,255,255,.2);
backdrop-filter:blur(20px);
transition:.4s;
}

.nav.mobile.active{
right:0;
}

/* overlay */

.overlay{
position:fixed;
width:100%;
height:100%;
background:rgba(0,0,0,.4);
opacity:0;
visibility:hidden;
transition:.3s;
}

.overlay.active{
opacity:1;
visibility:visible;
}

/* hero */

.hero{
height:50vh;
display:flex;
flex-direction:column;
justify-content:center;
align-items:center;
text-align:center;
background:#e8f2ff;
margin-top:70px;
}

.hero h1{
font-size:42px;
margin-bottom:10px;
}

/* slideshow */

.slideshow{
max-width:800px;
margin:40px auto;
}

.slides{
display:none;
}

.slides img{
width:100%;
border-radius:12px;
}

/* layout */

.container{
display:grid;
grid-template-columns:3fr 1fr;
gap:40px;
padding:60px 40px;
}

/* cards */

.cards{
display:grid;
grid-template-columns:repeat(auto-fit,minmax(220px,1fr));
gap:25px;
}

.card{
background:white;
border-radius:14px;
box-shadow:0 10px 30px rgba(0,0,0,.1);
padding:20px;
text-align:center;
}

.card img{
width:100%;
border-radius:10px;
transition:.4s;
margin-bottom:15px;
}

.card:hover img{
transform:scale(1.1);
}

/* sidebar */

.sidebar{
background:white;
padding:20px;
border-radius:14px;
box-shadow:0 10px 30px rgba(0,0,0,.1);
}

/* bottom menu */

.bottom-menu{
display:flex;
justify-content:center;
gap:25px;
padding:15px;
background:#00aaff;
}

.bottom-menu a{
color:white;
text-decoration:none;
}

/* footer */

footer{
background:#111;
color:white;
padding:40px;
}

.footer-grid{
display:grid;
grid-template-columns:1fr 1fr;
gap:20px;
}

.copy{
text-align:center;
margin-top:20px;
}

/* button top */

#topBtn{
position:fixed;
bottom:30px;
right:30px;
padding:12px 16px;
border:none;
border-radius:50%;
background:#00aaff;
color:white;
display:none;
cursor:pointer;
}

/* reveal */

.reveal{
opacity:0;
transform:translateY(40px);
transition:.6s;
}

.reveal.active{
opacity:1;
transform:none;
}

/* mobile */

@media(max-width:900px){

.burger{
display:flex;
}

.nav{
display:none;
}

.nav.mobile{
display:flex;
}

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

}