/* 页脚与头图透明 */
#footer {
    background: transparent !important;
}

#page-header {
    background: transparent !important;
}

#page-header:not(.not-top-img):before {
    position: absolute;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, .25) !important;
    content: '';
}

/* 白天模式遮罩透明 */
#footer::before {
    background: rgba(red, green, blue, alpha) !important;
}

#page-header::before {
    background: transparent !important;
}

/* 夜间模式遮罩透明 */
[data-theme="dark"] #footer::before {
    background: transparent !important;
}

[data-theme="dark"] #page-header::before {
    background: transparent !important;
}