.logo {
    padding: 20px;
    text-align: center;
    border-bottom: 1px solid rgba(65, 180, 255, 0.2);
    flex-shrink: 0;
    background: linear-gradient(135deg, rgba(10, 100, 200, 0.15), rgba(20, 66, 114, 0.15));
    position: relative;
}

.logo::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 60%;
    height: 2px;
    background: linear-gradient(90deg, transparent, var(--tech-blue-accent), transparent);
}

.logo h3 {
    margin: 0;
    font-size: 1.5rem;
    font-weight: 600;
    color: white;
    text-shadow: 0 2px 10px rgba(65, 180, 255, 0.3);
}

.nav-items {
    padding: 20px 0;
    flex: 1;
    overflow-y: auto;
}

.nav-item {
    padding: 12px 20px;
    cursor: pointer;
    transition: all 0.3s;
    display: flex;
    align-items: center;
    color: rgba(255,255,255,0.8);
    border-left: 3px solid transparent;
    margin: 4px 0;
}

.nav-item:hover {
    background: linear-gradient(90deg, rgba(65, 180, 255, 0.15), transparent);
    color: white;
    border-left-color: var(--tech-blue-accent);
    transform: translateX(3px);
}

.nav-item.active {
    background: linear-gradient(90deg, rgba(65, 180, 255, 0.25), rgba(65, 180, 255, 0.05));
    color: white;
    position: relative;
    border-left-color: var(--tech-blue-accent);
    box-shadow: 0 0 15px rgba(65, 180, 255, 0.2);
}

.nav-item.active::before {
    content: '';
    position: absolute;
    right: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 4px;
    height: 60%;
    background: var(--tech-blue-accent);
    border-radius: 4px 0 0 4px;
}

.nav-item i {
    margin-right: 10px;
    width: 20px;
    text-align: center;
    filter: drop-shadow(0 0 3px rgba(65, 180, 255, 0.5));
}

.user-section {
    flex-shrink: 0;
    padding: 20px;
    border-top: 1px solid rgba(65, 180, 255, 0.2);
    background: linear-gradient(135deg, rgba(10, 38, 71, 0.3), rgba(20, 66, 114, 0.2));
    backdrop-filter: blur(10px);
    box-shadow: 0 -4px 20px rgba(65, 180, 255, 0.1);
}

.user-info .username {
    font-size: 0.9rem;
    margin-bottom: 5px;
    font-weight: 500;
    color: white;
}

.user-info .login-time {
    font-size: 0.8rem;
    opacity: 0.7;
    color: white;
}

.user-info .expire-time {
    font-size: 0.8rem;
    margin-top: 5px;
    color: white;
    display: none; /* 临时隐藏到期时间，需要时删除这行即可 */
}

.user-info .expire-time .text-success {
    color: #4ade80 !important;
    font-weight: 500;
}

.user-info .expire-time .text-warning {
    color: #fbbf24 !important;
    font-weight: 500;
}

.user-info .expire-time .text-danger {
    color: #ef4444 !important;
    font-weight: 500;
}