/* ********** imports ********** */

/* import font files */
@font-face {
    font-family: SourceHanSansCN_R;
    src: url("../fonts/SourceHanSansCN_R.otf");
}
@font-face {
    font-family: SourceHanSansCN_M;
    src: url("../fonts/SourceHanSansCN_M.otf");
}
@font-face {
    font-family: SourceHanSansCN_B;
    src: url("../fonts/SourceHanSansCN_B.otf");
}
@font-face {
    font-family: PangmenZhendaoCushuti;
    src: url("../fonts/pangmenzhengdao_cushuti.ttf");
}

/* ********** globle ********** */

/* set the padding & margin of the body */
body {
    padding: 0;
    margin: 0;
}

/* ********** #tip part ********** */

/* set the styles & layout of the #tip part */
#tip {
    background-color: rgb(75, 75, 75);
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100vw;
    height: 30px;
}

/* set the styles of the <span> tag in the #tip part */
#tip span {
    font-family: SourceHanSansCN_M;
    color: white;
    line-height: 0;
    font-size: 0.87em;
    padding: 13px;
    z-index: 2;
}

/* ********** #header part ********** */

/* set the styles of the #header part */
#header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin: 12px 30px 12px 30px;
}
@media (width <= 600px) {
    #header {
        flex-direction: column;
        justify-content: center;
    }
}

/* set the layout of the .header-left part */
#header .header-left {
    display: flex;
    align-items: center;
}

/* set the laoyut of the .title part in the #header part */
#header .header-left .title {
    display: flex;
    flex-direction: column;
    align-items: center;
    word-spacing: 8px;
}

/* set the styles of the <h1> & <h2> tag */
#header .header-left h1, #header .header-left h2 {
    font-weight: normal;
    line-height: 0;
}
#header .header-left h1 {
    font-family: SourceHanSansCN_M;
}
#header .header-left h2 {
    font-family: SourceHanSansCN_B;
}
#header .header-left h2 {
    text-transform: uppercase;
    font-size: 0.7em;
}

/* set the width of the <img> tag in the #header part */
#header img {
    width: 100px;
}

/* set the styles of the .school-motto in the #header part */
#header .header-right .school-motto-wrap {
    font-family: PangmenZhendaoCushuti;
    font-size: 1.5em;
}
#header .header-right .school-motto-unwrap {
    font-family: PangmenZhendaoCushuti;
    font-size: 1.2em;
    display: none;
}
@media (width <= 600px) {
    #header .header-right .school-motto-wrap {
        display: none;
    }
    #header .header-right .school-motto-unwrap {
        display: block;
    }
}

/* ********** #nav part ********** */

/* set the styles & layout of the #nav part */
#nav {
    width: 100vw;
    height: 40px;
    background-color: rgb(61, 105, 181);
    display: flex;
    /* flex-direction: column; */
    justify-content: space-between;
    align-items: center;
}
@media (width <= 600px) {
    #nav {
        height: 80px;
        flex-direction: column;
        justify-content: center;
        gap: 3px;
    }
}

/* set the layout of the .nav-left & .nav-right */
#nav .nav-left, #nav .nav-right {
    display: flex;
    gap: 35px;
    margin: 0 20px 0 20px;
}
@media (width <= 600px) {
    #nav .nav-left, #nav .nav-right {
        gap: 25px;
    }
}

/* set the layout of the .nav-item */
#nav .nav-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    position: relative;
}

/* set the styles of the <a> tags in the .nav-item */
#nav .nav-item a {
    font-family: SourceHanSansCN_M;
    color: white;
    text-decoration: none;
    font-size: 1.13em;
}

/* set the styles & position of the .line in the .nav-item */
#nav .nav-item .line {
    width: 0px;
    height: 3px;
    background-color: white;
    position: relative;
    top: 5.32px;
    transition: all 0.2s ease-in-out 0s;
}
@media (width <= 600px) {
    #nav .nav-left .nav-item .line {
        position: absolute;
        top: -10.21px;
    }
    #nav .nav-right .nav-item .line {
        position: relative;
        top: 10.4px;
    }
}

/* run a animation when the <a> tag in the #nav part on hover */
#nav .nav-item a:hover + .line {
    width: 25px;
}

/* ********** #main part ********** */

/* set the styles & layout of the #main part */
#main {
    margin: 42px 35px 42px 35px;
}