/* defines light color */
:root {
  --color-light-bg-page: #EBEBEB;
  --color-light-bg-content: #F4F4F4;
  --color-light-bg-block: #EBEBEB;
  --color-light-bg-shadow: #E0E0E0;
  --color-light-fg-font-normal: #4E403E;
  --color-light-fg-font-hover: #555555;
  --color-light-fg-font-quote: #57606A;
  --color-light-fg-tiny-line: #e0e0e0;
  --color-light-fg-marker-quote: #BFBFBF;
  --color-light-fg-font-hyper: #4E403E;
  --color-light-fg-font-hyper-hover: #DE629E;
  --color-light-fg-hyperlink: #DE629E;
  --color-light-fg-hyperlink-hover: #CB3E50;
  --color-light-bg-pager-normal: #D4D4D4;
  --color-light-bg-pager-current: #E4E4E4;
  --color-light-bg-pager-hover: #ECECEC;
}

/* defines dark color */
:root {
  --color-dark-bg-page: #202124;
  --color-dark-bg-content: #262628;
  --color-dark-bg-block: #2B2B2B;
  --color-dark-bg-shadow: #505050;
  --color-dark-fg-font-normal: #C2C2B6;
  --color-dark-fg-font-hover: #D2D2D3;
  --color-dark-fg-font-quote: #8B8680;
  --color-dark-fg-tiny-line: #3B3B3B;
  --color-dark-fg-marker-quote: #6F6B66;
  --color-dark-fg-font-hyper: #C2C2B6;
  --color-dark-fg-font-hyper-hover: #DE629E;
  --color-dark-fg-hyperlink: #DE629E;
  --color-dark-fg-hyperlink-hover: #CB3E50;
  --color-dark-bg-pager-normal: #303030;
  --color-dark-bg-pager-current: #3A3A3E;
  --color-dark-bg-pager-hover: #444446;
}

:root {
  --color-bg-page: var(--color-light-bg-page);
  --color-bg-content: var(--color-light-bg-content);
  --color-bg-block: var(--color-light-bg-block);
  --color-bg-shadow: var(--color-light-bg-shadow);
  --color-fg-font-normal: var(--color-light-fg-font-normal);
  --color-fg-font-hover: var(--color-light-fg-font-hover);
  --color-fg-font-quote: var(--color-light-fg-font-quote);
  --color-fg-tiny-line: var(--color-light-fg-tiny-line);
  --color-fg-marker-quote: var(--color-light-fg-marker-quote);
  --color-fg-font-hyper: var(--color-light-fg-font-hyper);
  --color-fg-font-hyper-hover: var(--color-light-fg-font-hyper-hover);
  --color-fg-hyperlink: var(--color-light-fg-hyperlink);
  --color-fg-hyperlink-hover: var(--color-light-fg-hyperlink-hover);
  --color-bg-pager-normal: var(--color-light-bg-pager-normal);
  --color-bg-pager-current: var(--color-light-bg-pager-current);
  --color-bg-pager-hover: var(--color-light-bg-pager-hover);
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-bg-page: var(--color-dark-bg-page);
    --color-bg-content: var(--color-dark-bg-content);
    --color-bg-block: var(--color-dark-bg-block);
    --color-bg-shadow: var(--color-dark-bg-shadow);
    --color-fg-font-normal: var(--color-dark-fg-font-normal);
    --color-fg-font-hover: var(--color-dark-fg-font-hover);
    --color-fg-font-quote: var(--color-dark-fg-font-quote);
    --color-fg-tiny-line: var(--color-dark-fg-tiny-line);
    --color-fg-marker-quote: var(--color-dark-fg-marker-quote);
    --color-fg-font-hyper: var(--color-dark-fg-font-hyper);
    --color-fg-font-hyper-hover: var(--color-dark-fg-font-hyper-hover);
    --color-fg-hyperlink: var(--color-dark-fg-hyperlink);
    --color-fg-hyperlink-hover: var(--color-dark-fg-hyperlink-hover);
    --color-bg-pager-normal: var(--color-dark-bg-pager-normal);
    --color-bg-pager-current: var(--color-dark-bg-pager-current);
    --color-bg-pager-hover: var(--color-dark-bg-pager-hover);
  }
}

:root {
  --fonts-sans-en: "Noto Sans", "Droid Sans", "Calibri", "Arial";
  --fonts-sans-zh: "WenQuanYi Zen Hei", "WenQuanYi Micro Hei",
    "Noto Sans CJK", "Microsoft YaHei", "PingFang SC";
  --fonts-sans: var(--fonts-sans-en), var(--fonts-sans-zh), sans-serif;

  --fonts-serif-en: "Noto Serif", "Times New Roman";
  --fonts-serif-zh: "Noto Serif CJK", SimSun, STSong;
  --fonts-serif: var(--fonts-serif-en), var(--fonts-serif-zh), serif;

  --fonts-mono-en: "DejaVu Sans Mono", "Noto Sans Mono", "Consolas", "Courier";
  --fonts-mono-zh: "Noto Sans Mono CJK", "WenQuanYi Zen Hei Mono", "WenQuanYi Micro Hei Mono";
  --fonts-mono: var(--fonts-mono-en), var(--fonts-mono-zh), monospace;

  --len-0: 0.00rem;
  --len-1: 0.25rem;
  --len-2: 0.50rem;
  --len-3: 1.00rem;
  --len-4: 1.50rem;
  --len-5: 3.00rem;

  --font-size-0: 0.8125rem;
  --font-size-1: 0.875rem;
  --font-size-2: 1.000rem;
  --font-size-3: 1.125rem;
  --font-size-4: 1.250rem;
  --font-size-5: 1.500rem;
  --font-size-6: 2.000rem;
}


*,
::before,
::after {
  font-family: inherit;
  box-sizing: border-box;
}

html {
  font-family: var(--fonts-sans);
  font-size: 16px;
  color: var(--color-fg-font-normal);
}

/**************************************************************/
/* approximately set up the layout of header, footer and main */
/**************************************************************/

body {
  display: flex;
  flex-direction: column;

  min-height: 100vh;
  margin: 0;

  align-items: center;

  background-color: var(--color-bg-page);
}

/* set up padding and margin of some main elements */
.main-wrapper {
  margin-top: var(--len-5);
  margin-bottom: var(--len-5);
}

.main-wrapper {
  display: flex;
  flex-wrap: wrap;
}

.main-wrapper>* {
  height: fit-content;
}

.main {
  padding: var(--len-4);
}

.side {
  padding-left: var(--len-4);
}

.main {
  flex: 0 0 72%;
  width: 72%;
}

.side {
  flex: 0 0 28%;
  width: 28%;
}

/* mobile layout: place side to bottom */
@media (max-width: 991px) {
  .main {
    padding: var(--len-4);
  }

  .side {
    padding-left: 0;
    padding-top: var(--len-4);
  }

  .main {
    flex: 0 0 100%;
    width: 100%;
  }

  .side {
    flex: 0 0 100%;
    width: 100%;
  }
}

/* set light background */
.header-wrapper,
.footer,
.main,
.side-recent,
.side-categories,
.side-tags {
  background-color: var(--color-bg-content);
}

/* place header in the center of header-wrapper */
.header-wrapper {
  display: flex;
  justify-content: center;
}

/* let footer stay at bottom of screen */
.footer {
  margin-top: auto;
  margin-bottom: 0;
}


/********** set up break point **********/

.main-wrapper,
.header {
  max-width: 1140px;
}

@media (max-width: 1199px) {

  .main-wrapper,
  .header {
    max-width: 960px;
  }
}

@media (max-width: 991px) {

  .main-wrapper,
  .header {
    max-width: 720px;
  }
}

@media (max-width: 767px) {

  .main-wrapper,
  .header {
    max-width: 540px;
  }
}

@media (max-width: 575px) {

  .main-wrapper,
  .header {
    max-width: none;
  }
}

/* size the element who has breakpoint limitation */
/* .header, .main-wrapper, .main { width: 100vw; } */
/* .header-wrapper, .footer { width: 100vw; } */
.header-wrapper,
.footer {
  width: 100vw;
}

.main-wrapper {
  width: calc(100vw - 2 * var(--len-3));
}

/************************/
/* set up header layout */
/************************/

.header {
  padding: var(--len-3);
  width: 100%;
}

/* place title and menus horizonally */
.header {
  display: flex;
  flex-wrap: wrap;
  align-content: center;
  justify-content: space-between;
}

.header .menu {
  justify-content: center;
  align-items: center;
}

.header .site-title {
  text-align: center;
}

@media (max-width: 767px) {
  .header .site-title {
    padding-top: var(--len-4);

    flex: 0 0 100%;
  }

  .header .menu {
    flex-wrap: wrap;
    flex: 0 0 100%;

    margin-top: var(--len-3);
    padding-top: var(--len-3);
    border-top: 1px solid var(--color-fg-tiny-line);
  }
}

/* setup hyper link style */
.header .site-title {
  text-decoration: none;
  font-family: var(--fonts-serif);
  font-size: var(--font-size-6);
  font-weight: bold;
}

/********** set up menus layout **********/

/* menus and submenus, hover to display, and setup animation */
.header .menu-item .sub-menu {
  visibility: hidden;
  opacity: 0;
  transition: opacity 0.25s, visibility 0.25s;
}

.header .menu-item:hover .sub-menu {
  visibility: visible;
  opacity: 1;
}

.header .sub-menu {
  position: absolute;
}

/* menu direction */
.header .menu {
  display: flex;
  align-items: center;
}

.header .sub-menu {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

/* set up spacing of menu items in menu and sub-menu */
.header .menu>* {
  margin-right: var(--len-3);
}

.header .menu>*:last-child {
  margin-right: 0;
}

.header .sub-menu>* {
  margin-bottom: var(--len-2);
}

.header .sub-menu>*:last-child {
  margin-bottom: 0;
}

/* beautify sub menu style */
.header .sub-menu {
  background-color: var(--color-bg-content);
  padding: var(--len-2) var(--len-4);
  box-shadow: var(--color-bg-shadow) 0px 0px 3px 1px;
  border-radius: 3px;
}

/* beautify menu item */
.header .menu-item {
  font-family: var(--fonts-serif);
  font-size: var(--font-size-3);
  font-weight: bold;
}

.header a {
  color: var(--color-fg-font-normal);
  text-decoration: none;
}

.header a:hover {
  color: var(--color-fg-font-hover);
}

/************************/
/* set up footer layout */
/************************/

.footer {
  padding: var(--len-4) 0;
  font-size: var(--font-size-1);
}

.footer>* {
  margin-top: var(--len-2);
  margin-bottom: var(--len-2);
}

/* credit, license and social layout */
.footer .footer-row {
  display: flex;
  justify-content: center;
}

.footer .footer-item {
  margin-right: var(--len-3);
}

.footer .footer-item:last-child {
  margin-right: 0;
}

/* beautify hyper link style */
.footer {
  color: var(--color-fg-font-normal)
}

.footer a {
  color: var(--color-fg-hyperlink);
  text-decoration: none;
}

.footer a:hover {
  color: var(--color-fg-hyperlink-hover);
}

/**********************************/
/* set up home page's list layout */
/**********************************/

.list-item .tips {
  display: flex;
  flex-wrap: wrap;
  justify-content: start;
  align-items: flex-start;

  font-size: var(--font-size-1);
  color: var(--color-fg-font-quote);
}

.list-item .tips>* {
  margin-right: var(--len-3);
}

.list-item .tips>*:last-child {
  margin-right: 0;
}

.list-item .title a {
  text-decoration: none;
  color: var(--color-fg-font-normal);
}

.list-item .title a:hover {
  color: var(--color-fg-font-hover);
}

.list-item .tips a {
  text-decoration: none;
  color: var(--color-fg-hyperlink);
}

.list-item .tips a:hover {
  color: var(--color-fg-hyperlink-hover);
}

.list-item .title {
  margin: var(--len-2) 0 var(--len-3) 0;
}

.list-item .tags>*,
.list-item .categories>* {
  margin: 0 var(--len-1);
}

.list-item .summary>* {
  margin: 0;
}

.list-item .title {
  margin: 0 0 var(--len-2) 0;
}

.list-item .tips {
  margin: 0 0 var(--len-3) 0;
}

.list-item {
  border-bottom: 1px solid var(--color-fg-tiny-line);
}

.list-item:last-child {
  border-bottom: 0;
}

.list-item:first-child {
  padding-top: 0;
}

.list-item {
  padding: var(--len-3) 0;
}

.list-item:last-child {
  padding-bottom: 0;
}

/**********************/
/* set up side layout */
/**********************/

.side h2 {
  margin: 0;
}

.side ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

.side li {
  margin-bottom: var(--len-3);
}

.side li:last-child {
  margin-bottom: 0;
}

.side hr {
  border: none;
  height: 1px;
  background-color: var(--color-bg-content);

  margin: var(--len-2) 0;
}

.side>* {
  padding: var(--len-4);
}

.side>* {
  margin-bottom: var(--len-3);
}

.side>*:last-child {
  margin-bottom: 0;
}

.side a {
  color: var(--color-fg-font-normal);
  text-decoration: none;
}

.side a:hover {
  color: var(--color-fg-hyperlink);
}

/* horizontally place tags */
.side .side-tags li {
  display: inline-block;
  margin: var(--len-1) var(--len-1);
}

/*****************************/
/* set up single post layout */
/*****************************/

.single {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.single a {
  text-decoration: none;
  color: var(--color-fg-hyperlink);
}

.single a:hover {
  color: var(--color-fg-hyperlink-hover);
}

.single .title,
.single .tip,
.single .taxonomies,
.single .content {
  width: 100%;
}

.single .taxonomies {
  margin-top: var(--len-1);
}

.single>hr {
  border: none;
  background-color: var(--color-fg-tiny-line);
  height: 1px;

  width: 90%;
  margin: var(--len-3) 0;
}

.single .title,
.single .tip,
.single .taxonomies {
  text-align: center;
}

.single .tip,
.single .taxonomies {
  color: var(--color-fg-font-normal)
}

.single .taxonomies>* {
  display: inline-block;
}

.single .taxonomies>* {
  margin-right: var(--len-3);
}

.single .taxonomies>*:last-child {
  margin-right: 0;
}

.single .title {
  margin: var(--len-2) 0 var(--len-3) 0;
  font-size: var(--font-size-6);
}


/***** set up content style *****/

.content {
  line-height: 1.5;
}

.content code {
  font-family: var(--fonts-mono);

  background-color: var(--color-bg-block);

  padding: 0 2px;
  border: 1px solid var(--color-fg-tiny-line);
  border-radius: 2px;
  line-height: inherit;
  word-wrap: break-word;
}

/* keep in style with highlighting */
.content pre {
  background-color: var(--color-bg-block);
  border-radius: 3px;

  /* The copy button with absolute position need this.
   * https://developer.mozilla.org/en-US/docs/Web/CSS/position
   * https://developer.mozilla.org/en-US/docs/Web/CSS/Containing_block#identifying_the_containing_block
  */
  position: relative;
}

.content pre code {
  display: block;

  padding: var(--len-3);
  border: none;
  background-color: unset;
  overflow: auto;
  width: 100%;
}

.content blockquote {
  margin-top: 5px;
  margin-bottom: 5px;
  padding-left: 1em;
  margin-left: 0px;
  border-left: 3px solid var(--color-fg-marker-quote);
  color: var(--color-fg-font-quote);
}

.content hr {
  border: none;
  height: 2px;
  background-color: var(--color-fg-tiny-line);

  width: 80%;
  margin: var(--len-2) auto;
}

.content table {
  width: 100%;
  margin: 40px 0;
  border-collapse: collapse;
  line-height: 1.5em;
}

.content th,
.content td {
  text-align: left;
  padding-right: 20px;
  vertical-align: top;
}

.content table td,
.content table td {
  border-spacing: none;
  border-style: solid;
  padding: 10px 15px;
  border-width: 1px 0 0 0;
}

.content thead th,
.content thead th {
  text-align: left;
  padding: 10px 15px;
  height: 20px;
  font-weight: bold;
  color: #444;
  cursor: default;
  white-space: nowrap;
  border: 1px solid #dadadc;
}

.content tr>td {
  border: 1px solid #dadadc;
}

.content tr:nth-child(odd)>td {
  background: #fcfcfc;
}

.content h1,
.content h2,
.content h3 {
  font-weight: bold;
}

.content p,
.content pre {
  word-break: normal;
  overflow-wrap: anywhere;
}

.content img {
  max-width: 92%;
  vertical-align: middle;
}

.content figure.image-block {
  display: block;
  margin: 1em auto;
  text-align: center;
}

.content figure.image-block img {
  display: block;
  margin-left: auto;
  margin-right: auto;
}

.content .anchor {
  visibility: hidden;
}

.content h1:hover a,
.content h2:hover a,
.content h3:hover a,
.content h4:hover a {
  visibility: visible
}

.highlight pre {
  overflow-x: auto;
}

.highlight {
  max-width: 100%;
  overflow-x: auto;
}

/* the copy button added by /js/copy-code-button.js */
pre .copyCodeButton {
  position: absolute;
  top: var(--len-1);
  right: var(--len-3);

  font-family: var(--fonts-mono);
  color: var(--color-fg-hyperlink);
  cursor: pointer;
  visibility: hidden;
}

pre:hover .copyCodeButton {
  visibility: visible;
}

pre .copyCodeButton:hover {
  color: var(--color-fg-hyperlink-hover);
}

/**************************/
/* setup list page layout */
/**************************/

#archive {
  padding-left: var(--len-3);
}

#archive .group {
  margin: var(--len-4) auto;
}

#archive .group .key {
  font-size: var(--font-size-4);
  margin-bottom: var(--len-2);
}

#archive .group .value {
  display: block;
  font-size: var(--font-size-2);
  margin-bottom: 12px;
}

#archive .group .value {
  text-indent: -60px;
  padding-left: 60px;
}

#archive .group .value * {
  text-indent: 0;
}

#archive .group .value .date {
  display: inline-block;
  width: 60px;
}

#archive .group .value .title {
  display: inline;
}

#archive .group .value .date {
  color: var(--color-fg-font-normal);
}

#archive .group .value a {
  text-decoration: none;
}

#archive .group .value a {
  color: var(--color-fg-font-hyper);
}

#archive .group .value a:hover {
  color: var(--color-fg-font-hyper-hover);
}

#archive .group .value .tags {
  display: inline-block;
  margin-left: 7px;
}

#archive .group .value .tags {
  background: var(--color-bg-block);
  border-radius: 2px;
  padding: 4px 7px;
  font-size: var(--font-size-1);
  margin-right: 3px;
}

/**********************/
/* setup terms layout */
/**********************/

#tags {
  max-width: 700px;
  margin: 48px auto 0 auto;
  padding: 0 12px;
  text-align: center;
}

#tags .tag {
  display: inline-block;
  margin: 7px 7px;
}

@media (max-width: 700px) {
  #tags {
    margin: 0 auto 0 auto;
  }

  #tags .tag {
    display: inline-block;
    margin: 4px 5px;
  }
}

#tags .tag a {
  background: #f2f2f2;
  padding: 4px 7px;
  color: #757575;
  color: #404040;
  font-size: 14px;
  margin-right: 3px;
}

#tags .tag a:hover {
  color: #0366d6;
}

/***************************/
/* setup pagination layout */
/***************************/

.pagination {
  width: 100%;
  text-align: center;

  padding-top: var(--len-5);
}

.pagination a {
  display: inline-block;

  font-size: var(--font-size-2);

  border-radius: var(--len-5);
  width: var(--len-5);
  height: var(--len-5);
  line-height: var(--len-5);

  text-align: center;
  vertical-align: middle;

  text-decoration: none;

  color: var(--color-fg-font-normal);
  background-color: var(--color-bg-pager-normal);

  transition: background-color 0.25s;
}

.pagination a:hover {
  background-color: var(--color-bg-pager-hover);
}

.pagination a.current {
  background-color: var(--color-bg-pager-current);
  pointer-events: none;
  color: var(--color-fg-font-normal);
  cursor: default;
}

/***************************/
/* setup commenting layout */
/***************************/

.commenting {
  width: 85%;
}

/**********/
/** misc **/
/**********/

.archive-hint {
  padding-left: var(--len-4);
  color: var(--color-fg-font-quote);
}

.max-wrapper {
  width: 100%;
  height: 100%;
  padding: 0;
  margin: 0;
}

.smaller {
  font-size: 0.9rem;
  opacity: 0.8;
}