body{margin:0;font-family:'Segoe UI', Arial, sans-serif;background:#f4f6f8;color:#333;}
header{background:linear-gradient(135deg, #1e293b, #334155);color:#fff;padding:25px 20px;box-shadow:0 2px 8px rgba(0,0,0,0.1);}
header h1{margin:0;font-size:28px;}
.tboaps-amreinbue {background:#0f172a;padding:12px 20px;display:flex;gap:20px;}
.tboaps-amreinbue ul {list-style:none;margin:0;padding:0;display:flex;gap:15px;}
.tboaps-amreinbue a {color:#cbd5f5;text-decoration:none;font-weight:500;transition:0.2s;}
.tboaps-amreinbue a:hover {color:#fff;}
#bbaansnaerri {display:block;max-height:260px;overflow:hidden;}
#bbaansnaerri img {width:100%;display:block;height:auto;}
main{max-width:1200px;margin:auto;padding:25px;display:flex;gap:25px;}
article{flex:3;background:#fff;padding:25px;border-radius:12px;line-height:1.6;box-shadow:0 4px 15px rgba(0,0,0,0.05);}
nav{flex:1;background:#fff;padding:20px;border-radius:12px;height:fit-content;position:sticky;top:20px;box-shadow:0 4px 15px rgba(0,0,0,0.05);}
nav ul{list-style:none;margin:0;padding:0;}
nav li{margin-bottom:10px;}
nav a{text-decoration:none;color:#334155;font-size:14px;transition:0.2s;}
nav a:hover{color:#2563eb;padding-left:5px;}
footer{text-align:center;padding:25px;background:#1e293b;color:#cbd5f5;margin-top:40px;}
article h1,  article h2,  article h3{margin-top:25px;color:#1e293b;}
nav::before{content:"Содержание";display:block;font-weight:bold;margin-bottom:15px;font-size:16px;}
@media (max-width: 900px) {
main{flex-direction:column;}
nav{position:static;}

}