body {
    margin: 0;
    font-family: Arial, sans-serif;
    background: #f2f4f7;
}

header {
    background: #fff;
    color: #333;
    height: 60px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 20px;
    border-bottom: 1px solid #ddd;
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 10;
}

.logo {
    font-size: 20px;
    font-weight: bold;
}

.user-info {
    display: flex;
    align-items: center;
}

.user-info .user-img {
    width: 35px;
    height: 35px;
    border-radius: 50%;
    margin-right: 10px;
}

aside {
    background: #1b2133;
    color: white;
    width: 200px;
    position: fixed;
    top: 60px;
    bottom: 40px;
    left: 0;
    padding: 20px;
}

aside h3 {
    font-size: 16px;
    margin-bottom: 10px;
    color: #ccc;
}

aside ul {
    list-style: none;
    padding: 0;
}

aside ul li {
    margin: 10px 0;
}

aside ul li a {
    color: #ccc;
    text-decoration: none;
    display: block;
    padding: 8px 10px;
    border-radius: 6px;
}

aside ul li a:hover,
aside ul li a.active {
    background: #2b3350;
    color: #fff;
}

main {
    margin-left: 220px;
    margin-top: 60px;
    margin-bottom: 40px;
    padding: 20px;
    background: #f2f4f7;
    min-height: calc(100vh - 100px);
}

footer {
    position: fixed;
    bottom: 0;
    width: 100%;
    height: 40px;
    background: #fff;
    border-top: 1px solid #ddd;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 14px;
}