* {
    margin: 0;
    padding: 0;
}

.carousel a {
    list-style: none;

}

.carousel li {
    list-style: none;
    display: flex;
    width: 100%;
    justify-content: center;
    align-items: center;
}

.carousel {
    width: 100%;
}

.carousel .content {
    height: 300px;
    margin: 0 auto 0;
    position: relative;
}

.carousel #item {
    width: 100%;
    height: 100%;

}

.carousel .item {
    width: 100%;
    position: absolute;
    opacity: 0;
    transition: all 1s;
    overflow: hidden;
}

.carousel .item.active {
    opacity: 1;
}

.carousel img {
    /*width: 100%;*/

    height: 300px;
}

.carousel #btn-left {
    width: 30px;
    height: 69px;
    font-size: 30px;
    color: white;
    background-color: rgba(0, 0, 0, 0.4);
    line-height: 69px;
    padding-left: 5px;
    z-index: 10; /*始终显示在图片的上层*/
    position: absolute;
    left: 40px;
    top: 50%;
    transform: translateY(-60%); /*使按钮向上偏移居中对齐*/
    cursor: pointer;
    opacity: 0; /*平时隐藏*/
    user-select: none;
    border-radius: 8px;
    transition: opacity 0.3s ease-in-out,background-color 0.3s ease-in-out;
}

.carousel:hover #btn-left {
    /*鼠标滑入，显示图标*/
    opacity: 1;
}
#btn-left:hover {
    background-color: rgba(0, 0, 0, 0.65);
}
.carousel #btn-right {
    border-radius: 8px;
    user-select: none;
    width: 26px;
    height: 69px;
    font-size: 30px;
    color: white;
    background-color: rgba(0, 0, 0, 0.4);
    line-height: 69px;
    padding-left: 5px;
    z-index: 10;
    position: absolute;
    right: 40px;
    top: 50%;
    cursor: pointer;
    opacity: 0;
    transform: translateY(-60%);
    transition: opacity 0.3s ease-in-out,background-color 0.3s ease-in-out;
}

.carousel:hover #btn-right {
    opacity: 1;
}
#btn-right:hover {
    background-color: rgba(0, 0, 0, 0.65);
}
.carousel #circle {
    height: 20px;
    display: flex;
    position: absolute;
    bottom: 5px;
    left: calc(50% - 50px);

    align-items: center;
    padding-bottom: 1px;
    border-radius: 10px;
}

.carousel .circle {
    width: 10px;
    height: 10px;
    border-radius: 10px;
    /*border: 2px solid white;*/
    background: rgba(0, 0, 0, 0.4);
    box-shadow: 0 0 5px rgba(0, 0, 0, 0.5);
    cursor: pointer;
    margin: 5px;
}

.carousel .white {
    background-color: #FFFFFF;
}
