.sidebar {
    min-height: 100vh;
    width: 220px;
    background: #212529;
}
.sidebar a {
    color: #ccc;
    padding: 12px 20px;
    display: block;
    text-decoration: none;
}
.sidebar a.active, .sidebar a:hover {
    background: #343a40;
    color: white;
}
.content {
    padding: 20px;
}
.stat-card {
    border-radius: 8px;
    padding: 20px;
    color: white;
}
body {
    background-color: #f8f9fa; /* 统一背景色 */
}
input,button{
    outline: none;
}
a{
    text-decoration: none;
}

.login-box {
    max-width: 500px;
    padding: 2rem;
    margin: auto;
    background: white;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.08);
}