*{margin:0;padding:0;box-sizing:border-box}
body{font-family:Segoe UI,Arial,sans-serif;color:#1e2a2f;background:#f7f9fa;line-height:1.6}
header{display:flex;align-items:center;justify-content:space-between;background:#0f3d3e;color:#fff;padding:15px 25px}
header img{height:48px}
nav{position:fixed;top:78px;left:0;width:260px;background:#123f5a;height:100%;overflow:auto}
nav a{display:block;color:#fff;padding:14px 20px;text-decoration:none;border-bottom:1px solid rgba(255,255,255,.1)}
nav a:hover{background:#0f3d3e}
main{margin-left:260px}
section{padding:60px 50px;animation:fadeUp 1s ease}
.alt{background:#eef4f5}
img{max-width:100%;border-radius:6px;transition:transform .8s}
img:hover{transform:scale(1.05)}
footer{background:#0f3d3e;color:#fff;padding:30px;font-size:14px}
form input,form textarea{width:100%;padding:10px;border:1px solid #ccc;border-radius:4px;margin-bottom:12px}
form button{background:#123f5a;color:#fff;padding:12px;border:none;border-radius:4px}
@keyframes fadeUp{from{opacity:0;transform:translateY(20px)}to{opacity:1;transform:none}}
@media(max-width:900px){
nav{position:relative;width:100%;top:0}
main{margin:0}
}