.banner {
    width: 100%;
    height: 100vh;
    position: relative;
    overflow: hidden;
}

.banner-item {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    visibility: hidden;
    transition: opacity 1s ease, visibility 1s ease;
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    background-color: #ccc;
}

.banner-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

.banner-item.active {
    opacity: 1;
    visibility: visible;
    z-index: 1;
}

.banner-dots {
    position: absolute;
    bottom: 8%;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 14px;
    z-index: 3;
}

.dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: #fff;
    opacity: 0.5;
    cursor: pointer;
    transition: all 0.3s;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.3);
}

.dot.active {
    opacity: 1;
    transform: scale(1.25);
    background: #F5F9FD;
}

/* === 左右切换箭头 === */
.banner-arrow {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    width: 48px;
    height: 48px;
    border: none;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.18);
    backdrop-filter: blur(1px);
    color: #fff;
    cursor: pointer;
    z-index: 4;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    box-shadow: 0 4px 14px rgba(0, 0, 0, 0.18);
}

.banner-arrow svg {
    width: 22px;
    height: 22px;
}

.banner-arrow:hover {
    background: rgba(204, 229, 255, 0.8);
    transform: translateY(-50%) scale(1.08);
}

.banner-prev {
    left: 28px;
}

.banner-next {
    right: 28px;
}

/* 桌面端：鼠标 hover 时显示 */
.banner:hover .banner-arrow {
    opacity: 1;
    visibility: visible;
}

/* 移动端：常显示 */
@media (max-width: 768px) {
    .banner-arrow {
        opacity: 1;
        visibility: visible;
        width: 40px;
        height: 40px;
    }

    .banner-arrow svg {
        width: 18px;
        height: 18px;
    }

    .banner-prev {
        left: 14px;
    }

    .banner-next {
        right: 14px;
    }
}

@media (max-width: 480px) {
    .banner-arrow {
        width: 36px;
        height: 36px;
    }

    .banner-arrow svg {
        width: 16px;
        height: 16px;
    }

    .banner-prev {
        left: 10px;
    }

    .banner-next {
        right: 10px;
    }
}

@media (max-width: 992px) {

    .banner {
        height: 400px;
    }

}

@media (max-width: 768px) {

    .banner {
        height: 280px;
    }

    .banner-dots {
        gap: 10px;
        bottom: 6%;
    }

    .dot {
        width: 10px;
        height: 10px;
    }

}

@media (max-width: 480px) {
    .banner {
        height: 240px;
    }

    .banner-dots {
        gap: 8px;
        bottom: 5%;
    }

    .dot {
        width: 9px;
        height: 9px;
    }

}