/* 移动端悬浮按钮：深色模式 / 返回顶部（与目录按钮同列） */
.Xc_mfab {
    display: none;
}

@media (max-width: 992px) {
    .Xc_mfab {
        display: block;
    }

    .Xc_mfab__btn {
        position: fixed;
        right: 16px;
        z-index: 998;
        width: 44px;
        height: 44px;
        padding: 0;
        border: none;
        border-radius: 50%;
        background: var(--background);
        color: var(--main);
        box-shadow: 0 4px 14px rgba(0, 0, 0, 0.16);
        display: flex;
        align-items: center;
        justify-content: center;
        cursor: pointer;
        -webkit-tap-highlight-color: transparent;
        -webkit-backdrop-filter: blur(6px);
        backdrop-filter: blur(6px);
        transition: transform 0.25s, opacity 0.25s, visibility 0.25s, color 0.25s;
    }

    .Xc_mfab__btn:active {
        transform: scale(0.94);
    }

    .Xc_mfab__btn:focus-visible {
        outline: 2px solid var(--theme);
        outline-offset: 2px;
    }

    /* 从下往上：返回顶部 -> 深色模式 -> 目录 */
    .Xc_mfab__top {
        bottom: calc(30px + env(safe-area-inset-bottom));
    }

    .Xc_mfab__mode {
        bottom: calc(82px + env(safe-area-inset-bottom));
    }

    .Xc_toc_fab {
        bottom: calc(134px + env(safe-area-inset-bottom)) !important;
    }

    .Xc_mfab__top.is-hidden {
        opacity: 0;
        visibility: hidden;
        transform: translateY(10px);
        pointer-events: none;
    }

    /* 两个图标叠放，按当前模式显示其一 */
    .Xc_mfab__mode .icon-sun,
    html[data-night='night'] .Xc_mfab__mode .icon-moon {
        display: none;
    }

    html[data-night='night'] .Xc_mfab__mode .icon-sun {
        display: block;
    }
}

@media (max-width: 768px) {
    .Xc_mfab__btn {
        right: 12px;
        width: 40px;
        height: 40px;
    }

    .Xc_mfab__top {
        bottom: calc(24px + env(safe-area-inset-bottom));
    }

    .Xc_mfab__mode {
        bottom: calc(72px + env(safe-area-inset-bottom));
    }

    .Xc_toc_fab {
        bottom: calc(120px + env(safe-area-inset-bottom)) !important;
    }
}

@media print {
    .Xc_mfab {
        display: none !important;
    }
}