:root, html, body {
    margin: 0;
    padding: 0;
    border: 0;
    outline: 0;
    width: 100%;
    height: 100%;
}

body {
    -webkit-text-size-adjust: 100%!important;
    background: #f2f2f2;
}

h1 {
    position: absolute;
    z-index: 999999;

    display: flex;
    justify-content: center;
    align-items: center;

    margin: 0;
    padding: 0;
    border: 0;
    outline: 0;
    width: 100%;
    height: 100%;
    box-sizing: border-box;
    background: transparent;

    font-size: 10vmin;
    color: #333333aa; /* rrggbbaa */
}

a {
    outline: none;
    text-decoration:none;
    background-color: transparent;
    -webkit-tap-highlight-color: transparent;   /* 去掉点击高亮 */
    -webkit-touch-callout: none;                /* 禁止长按弹出菜单 */
}

a:link {color: #000;}       /* 未访问 */
a:visited {color: #000;}    /* 已访问 */
a:focus {color: #00f;}      /* 焦点; [Tab]键 切换 见效果 */
a:hover {color: #f00;}      /* 鼠标悬停 */
a:active {color: #0f0;}     /* 鼠标按下 */

.img-none {
    position: fixed;
    z-index: 1;

    margin: 0;
    padding: 0;
    border: 0;
    outline: none;

    display: flex;
    justify-content: center;
    align-items: center;

    width: 100%;
    height: 100%;
    filter: opacity(4%);
    font-size: 0px;
    line-height: 0px;
}

img {
    width: 100vmin;
    height: 100vmin;
}