body {
    background: #f4f7fc;
}
.sidebar {
    background: #2c3e50;
    min-height: 100vh;
    padding: 0;
}
.sidebar a {
    color: #ecf0f1;
    text-decoration: none;
    padding: 12px 20px;
    display: block;
    border-left: 4px solid transparent;
    transition: 0.2s;
}
.sidebar a:hover {
    background: #34495e;
    border-left-color: #1abc9c;
}
.sidebar a.active {
    background: #1abc9c;
    border-left-color: #fff;
}
.main-content {
    padding: 20px;
}
.card {
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}
.table th {
    background: #2c3e50;
    color: white;
}