:root {
    --font-family: 'Noto Serif SC', serif;
    --line-height: 1.8;
    --primary: #1e88e5;
    --card-box-shadow: 0 15px 35px rgba(50, 50, 93, 0.1), 0 5px 15px rgba(0, 0, 0, 0.10) !important;
}

:root:not([data-theme=dark]), [data-theme=light] {
    --del-color: color: rgba(23, 43, 77, 0.5);
}

@media only screen and (prefers-color-scheme: dark) {
    :root:not([data-theme=light]) {
        --del-color: color: rgba(23, 43, 77, 0.5);
    }
}

[data-theme=dark] {
    --del-color: color: rgba(23, 43, 77, 0.5);
    --card-box-shadow: 0 15px 35px rgba(50, 50, 93, 0.1), 0 5px 15px rgba(255, 255, 255, 0.10) !important;
}

@media (min-width:576px) { :root { --font-size:17px } }
@media (min-width:768px) { :root { --font-size:17px } }
@media (min-width:992px) { :root { --font-size:17px } }
@media (min-width:1200px) { :root { --font-size:17px } }

@media (min-width: 576px) {
    body > footer, body > header, body > main, section {
        --block-spacing-vertical:calc(var(--spacing) * 1)
    }
}
@media (min-width: 768px) {
    body > footer, body > header, body > main, section {
        --block-spacing-vertical:calc(var(--spacing) * 1.5)
    }
}
@media (min-width: 992px) {
    body > footer, body > header, body > main, section {
        --block-spacing-vertical:calc(var(--spacing) * 1.75)
    }
}
@media (min-width: 1200px) {
    body > footer, body > header, body > main, section {
        --block-spacing-vertical: calc(var(--spacing) * 2);
    }
}

html {
    scroll-behavior: smooth;
    transition: 0.5s ease;
    scroll-snap-type: y mandatory;
}

.container {
    max-width: 820px;
    padding-left: var(--spacing);
    padding-right: var(--spacing);
}

header, footer, nav {
    text-align: center;
}

header {
    padding-top: calc(var(--spacing) * 4);
    padding-bottom: calc(var(--spacing) * 1);
}

body>main {
    padding: inherit;
}

section {
    position: relative;
    margin-bottom: 0;
}

hr {
    --block-spacing-vertical: calc(var(--spacing) * 2);
    margin-top: var(--block-spacing-vertical);
    margin-bottom: var(--block-spacing-vertical);
    width: 100%;
}

/* What happened here? */
ol, ul {
    padding-inline-start: calc(var(--spacing) * 2)
}

/* 莫名其妙吧，margin-top 0？ */
h1, h2, h3, h4, h5, h6 {
    margin-top: var(--typography-spacing-vertical);
}

/* 莫名其妙吧，margin-bottom 默认设置这么大，有法看么 =_= */
h1 { --typography-spacing-vertical: 1.5rem; }
h2 { --typography-spacing-vertical: 1.25rem; }
h3 { --typography-spacing-vertical: 1.0rem; }
h4 { --typography-spacing-vertical: 0.75rem; }
h5 { --typography-spacing-vertical: 0.5rem; }

.meta-info {
    color: var(--muted-color);
}

.shadow {
    box-shadow: var(--card-box-shadow) !important;
}

.text-shadow {
    text-shadow: var(--card-box-shadow) !important;
}

.rounded {
    border-radius: var(--border-radius);
}

.circle {
    border-radius: 50%;
}

.container {
    max-width: 820px;
}

.flex-wrap {
    display: flex;
    flex-flow: column nowrap;
    justify-content: center;
}

.flex-center {
    align-items: center;
}

.flex-box-sm {
    display: flex;
    flex-flow: column nowrap;
    justify-content: center;
    align-items: center;
}

.slide {
    scroll-snap-align: start;
    scroll-snap-stop: always;
}

.full-height {
    min-height: 100vh;
}

.navbar {
    --font-weight: 500;
}

.navbar a .active {
    border-bottom: solid var(--primary);
}

nav a { color: var(--secondary); }
nav a:hover { color: var(--secondary-hover); }
nav a:focus { color: var(--secondary-focus); }

blockquote {
    --font-family: Kai, "Kaiti SC", Georgia, "Times New Roman", Times, KaiTi, BiauKai, 'Noto Serif SC', serif;
    border-left: 10px solid var(--blockquote-border-color);
    box-shadow: var(--card-box-shadow) !important;
    border-radius: var(--border-radius);
}
blockquote::before {
    --font-family: serif;
    font-family: var(--font-family);
    color: var(--blockquote-border-color);
    content: "“";
    font-size: calc(var(--font-size) * 5);
    /* vertical-align: -.4em; */
    line-height: 0;
}

footer a {
    --color: var(--secondary);
}

#nis:before {
    content: url(../img/beian.png);
    vertical-align: middle;
    display: inline-block;
    line-height: var(--line-height);
}

#hnu:before {
    content: url(../img/hnu.png);
    /* width: var(--font-size);
    height: var(--font-size); */
    vertical-align: middle;
    display: inline-block;
    line-height: var(--line-height);
}

.theme-switcher {
    position: fixed;
    top: 10px;
    right: 20px;
    width: 15px;
    height: 15px;
}

a {
    position: relative;
}

a:hover {
    text-decoration: none;
}

a::before {  
    transform: scaleX(0);
    transform-origin: right;
}

a:hover::before {
    transform: scaleX(1);
    transform-origin: left;
}

a::before {
    content: " ";
    display: block;
    position: absolute;
    top: 0; right: 0; bottom: 0; left: 0;
    /*inset: 0 0 0 0;*/
    background: var(--primary-focus);
    z-index: -1;
    transition: transform .3s ease;
    border-radius: 5px;
}

@media (min-width: 576px) {
    .avatar {
        position: absolute;
        right: 0;
    }
}

.superbold {
    font-weight: 900;
}

.bg-image-1 {
    background-image: linear-gradient(30deg, #2980b9, #6dd5fa, #ffffff);
    
}

.gradient-1 {
    background-image: linear-gradient(30deg, #415462, #C78EA8);
    color: transparent;
    background-clip: text;
    -webkit-background-clip: text;
}

.gradient-2 {
    background-image: linear-gradient(30deg, #fdc830, #f37335);
    color: transparent;
    background-clip: text;
    -webkit-background-clip: text;
}

.gradient-3 {
    background-image: linear-gradient(30deg, #003d4d, #00c996);
    color: transparent;
    background-clip: text;
    -webkit-background-clip: text;
}

.gradient-quzhou {
    background-image: linear-gradient(60deg, #00f260, #0575e6);
    color: transparent;
    background-clip: text;
    -webkit-background-clip: text;
}

.gradient-hnu {
    background-image: linear-gradient(30deg, #e53935, #c13432);
    color: transparent;
    background-clip: text;
    -webkit-background-clip: text;
}

.fade-in {
    animation: fade-in .7s ease, slide-in .7s ease;
}

@keyframes fade-in {
    from { opacity: 0 }
}

@keyframes slide-in {
    from { transform: translateY(10px) }
}

.arrow {
    position: absolute;
    bottom: 0px;
    left: auto;
    right: auto;
}

@media (min-width: 992px){
    div.border-grid > div {
        position: relative;
    }
    
    div.border-grid > div:after {
        content: " ";
        display: block;
        position: absolute;
        background: var(--muted-border-color);
        width: 1px;
        height: 100%;
        top: 0;
        right: calc(-0.5 * var(--grid-spacing-horizontal));
    }
    
    div.border-grid > div:last-child:after {
        display: none;
    }
}

.knowledge-wall {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}