index.css

* {
    font-family: Arial, Helvetica, sans-serif;
}
body,
html {
    height: 100%;
    position: relative;
    overflow-x: hidden;
}
body {
    background-color: rgb(240, 240, 240);
    background-attachment: fixed;
    background-position: center;
    background-size: 100% auto;
    /* background-repeat: no-repeat; */
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
#alarm {
    font-size: 130px;
    position: absolute;
    z-index: -1;
    width: 100%;
    top: 0;
    margin: 10px;
    text-align: center;
    color: rgba(0, 0, 0, 0.65);
	text-shadow: 0 0 10px rgba(255, 255, 255, 0.7);
}
#title1 {
    user-select: none;
    margin-top: 110px;
    margin-bottom: 0px;
    text-align: center;
    white-space: nowrap;
    color: #fbfbfb;
    text-shadow: 1px 1px 6px #000;
    font-size: 3em;
}
#title1 > img {
    height: 1.5em;
    width: 1.5em;
    padding: 0 0.2em;
}

#title2 {
    user-select: none;
    margin-top: 10px;
    margin-bottom: 0px;
    text-align: center;
    white-space: nowrap;
    color: rgba(255, 255, 255, 0.92);
    text-shadow: 1px 1px 10px #4e4e4e;
    font-size: 1.7em;
    font-weight: 100;
}

#title1 > a,
#title1 > a:hover,
#title1 > a:focus,
#title1 > a:active,
#title1 > a:visited {
    color: #fbfbfb;
    outline: none;
    text-decoration: none;
}

.style_toggle {
    right: 3.9rem;
    top: 1.8rem;
    height: 2.4rem;
    width: 4.1rem;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    position: fixed;
    z-index: 5;
}

.style_toggle:hover,
.style_toggle:active {
    transition: all 0.2s ease-in-out;
    background-color: rgba(0, 0, 0, 0.6);
}

#style_toggle_btn {
    display: block;
    height: 2.4rem;
    width: 4.1rem;
    cursor: pointer;
    border-left: 0.9rem solid transparent;
    border-right: 0.9rem solid transparent;
    border-top: 0.4rem solid transparent;
    border-bottom: 0.4rem solid transparent;
    background-clip: content-box;
    background-image: url(./images/btn1.svg);
    background-color: rgba(0, 0, 0, 0);
}

:focus {
    outline: 1px solid rgba(255, 255, 255, 0.6);
}

.style_toggle_menu {
    right: 3.9rem;
    top: 5rem;
    width: 18rem;
    display: block;
    position: fixed;
    color: #333;
    background: #fff;
    box-shadow: 0 1.28rem 2.28rem rgba(0, 0, 0, 0.22), 0 0.24rem 0.72rem rgba(0, 0, 0, 0.18);
    z-index: 5;
}

#style_toggle_header {
    display: inline-block;
    height: 1rem;
    padding: 0rem 1rem;
    font-size: 0.8rem;
    line-height: 1rem;
}

.style_toggle_item {
    display: flex;
    flex-direction: row;
    height: 1.8rem;
    padding: 0.8rem 1rem;
    align-content: center;
}

.style_toggle_item:hover {
    background-color: rgba(0, 0, 0, 0.08);
}

.style_toggle_item:active {
    background-color: rgba(0, 0, 0, 0.2);
}

.style_toggle_item span {
    padding-left: 0.8rem;
    align-content: center;
    line-height: 1.8rem;
}

.style_toggle_item img,
.style_toggle_item svg {
    display: inline-block;
    width: 1.8rem;
    height: 1.8rem;
    justify-content: center;
}

#bing {
    background-image: url('images/Bing.png');
    background-position: center;
    background-size: 60px 20px;
    background-repeat: no-repeat;
}

#baidu {
    background-image: url('images/Baidu.png');
    background-position: center;
    background-size: 60px 20px;
    background-repeat: no-repeat;
}

#google {
    background-image: url('https://search.library.edu.eu.org/images/branding/googlelogo/1x/googlelogo_color_272x92dp.png');
    background-position: center;
    background-size: 45px 15px;
    background-repeat: no-repeat;
}