/* 三层图片遮罩（首屏插屏） */
#ovMask {
    position: fixed;
    inset: 0;
    z-index: 999999;
    background: rgba(0, 0, 0, 0.9);
    display: flex;
    flex-direction: column;
    align-items: center;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
    padding: 56px 16px 48px;
    box-sizing: border-box;
}

/* 关闭按钮固定右上角，滚动时始终可见 */
.ov-close {
    position: fixed;
    top: 16px;
    right: 18px;
    width: 40px;
    height: 40px;
    line-height: 38px;
    text-align: center;
    font-size: 26px;
    color: #fff;
    background: rgba(255, 255, 255, 0.16);
    border: 1px solid rgba(255, 255, 255, 0.35);
    border-radius: 50%;
    cursor: pointer;
    user-select: none;
    z-index: 1000000;
    transition: background .2s;
}
.ov-close:hover { background: rgba(255, 255, 255, 0.35); }

.ov-card {
    position: relative;
    width: 1000px;
    max-width: 100%;
    margin: 0 auto;
    background: transparent;
}

.ov-title {
    color: #fff;
    font-size: 18px;
    font-weight: bold;
    text-align: center;
    margin: 0 0 18px;
    letter-spacing: 1px;
}

.ov-row {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    justify-content: center;
    margin-bottom: 12px;
}

.ov-row a {
    display: block;
    overflow: hidden;
    border-radius: 8px;
    box-shadow: 0 4px 14px rgba(0, 0, 0, .45);
    transition: transform .18s;
}
.ov-row a:hover { transform: translateY(-2px); }

.ov-row a img {
    display: block;
    width: 100%;
    object-fit: cover;
    border-radius: 8px;
}

/* 第1层 2 张大图 */
.ov-row1 a { width: calc(50% - 6px); }
.ov-row1 a img { height: 300px; }

/* 第2层 4 张图 */
.ov-row2 a { width: calc(25% - 9px); }
.ov-row2 a img { height: 190px; }

/* 第3层 10 张小图 */
.ov-row3 a { width: calc(10% - 11px); }
.ov-row3 a img { height: 110px; }

@media (max-width: 640px) {
    #ovMask { padding: 54px 10px 40px; }
    .ov-title { font-size: 16px; }

    .ov-row1 a { width: 100%; }
    .ov-row1 a img { height: 180px; }

    .ov-row2 a { width: calc(50% - 6px); }
    .ov-row2 a img { height: 120px; }

    .ov-row3 a { width: calc(33.33% - 8px); }
    .ov-row3 a img { height: 84px; }

    .ov-close { width: 36px; height: 36px; line-height: 34px; font-size: 23px; }
}