.topic-layout {
    overflow: hidden;
}

.topic-sidebar {
    float: left;
    width: 220px;
    margin-right: 20px;
    border-radius: 4px;
    overflow: hidden;
    background: #ffffff;
    box-shadow: 0 4px 18px rgba(4, 44, 101, 0.1);
}

.topic-sidebar-head {
    position: relative;
    height: 100px;
    box-sizing: border-box;
    background: #0073c0;
    color: #ffffff;
    overflow: hidden;
}

.topic-sidebar-head-bg {
    position: absolute;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.topic-sidebar-item {
    display: flex;
    align-items: center;
    position: relative;
    width: 100%;
    min-height: 64px;
    padding: 12px 12px 12px 20px;
    border-bottom: 1px solid #eef1f5;
    background: #ffffff;
    box-sizing: border-box;
}

.topic-sidebar-item.is-active {
    border-left: 4px solid #0273c3;
    padding-left: 16px;
    background: linear-gradient(90deg, rgba(2, 115, 195, 0.08) 0%, rgba(255, 255, 255, 0) 100%), #ffffff;
}

.topic-sidebar-icon {
    width: 18px;
    height: 18px;
    margin-right: 10px;
    flex-shrink: 0;
    object-fit: contain;
}

.topic-sidebar-text {
    flex: 1;
    color: #4a4a4a;
    font-size: 16px;
    line-height: 1.5;
    letter-spacing: 0.2px;
}

.topic-sidebar-item.is-active .topic-sidebar-text {
    color: #0273c3;
}