body{margin:0;font-family:Arial,Helvetica,sans-serif;background:#f3f4f6}
.sidebar{width:260px;background:#000;color:#fff;height:100vh;position:fixed;padding:20px}
.main{margin-left:260px;padding:24px}
.button{display:block;width:100%;text-align:left;padding:10px;border:none;background:transparent;color:#fff;cursor:pointer}
.button:hover{background:#1f2937}
.card{background:#fff;padding:20px;border-radius:16px;box-shadow:0 4px 10px rgba(0,0,0,0.05)}
.grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}
textarea,input{width:100%;padding:10px;margin-bottom:10px}
.btn{background:#000;color:#fff;padding:10px 16px;border:none;border-radius:8px;cursor:pointer}