/* 基础布局 */
.gallery-container {
    width: 100%;
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
    box-sizing: border-box;
}

.image-wrapper {
    position: relative;
    width: 100%;
    height: 0;
    padding-bottom: 177.78%; /* 9:16比例 */
    overflow: hidden;
    border-radius: 10px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
}

/* 图片样式 */
.image-wrapper img {
    position: absolute;
    width: 100%;
    height: 100%;
    object-fit: cover;
    opacity: 0;
    transition: opacity 0.5s ease-in-out;
    cursor: pointer;
    border-radius: 8px;
}

/* 激活状态 */
.image-wrapper img.active {
    opacity: 1;
}

/* 响应式调整 */
@media (max-width: 600px) {
    .image-wrapper {
        padding-bottom: 177.78%; /* 手机端也保持9:16比例 */
    }
}

.side-btn {
    position: fixed;
    top: 0;
    width: 49.8vw;      /* 横向覆盖页面20%，可调整 */
    height: 100vh;    /* 纵向覆盖整个视口 */
    z-index: 10;
    cursor: pointer;
    pointer-events: auto;
}
.side-btn.left {
    left: 0;
}
.side-btn.right {
    right: 0;
}

/* 让按钮区域不遮挡图片点击 */
.image-wrapper {
    position: relative;
    z-index: 1;
}

.side-btn:hover {
    background: rgba(0,0,0,0.15);
    transition: background 0.2s;
}