@font-face {
  font-family: QIJI;
  font-display: swap;
  src:
    url("https://cdn.jsdelivr.net/gh/wenyan-lang/book@3899aad7a917d0f000716ca97fe29221fe4b56d6/assets/font.woff2") format("woff2"),
    url("https://cdn.jsdelivr.net/gh/wenyan-lang/book@3899aad7a917d0f000716ca97fe29221fe4b56d6/assets/font.ttf") format("truetype");
}

:root {
  color-scheme: light;
  --page: #efefef;
  --paper: #f4f4f2;
  --paper-deep: #e9e9e6;
  --ink: #292929;
  --ink-soft: #707070;
  --ink-faint: #a8a8a8;
  --line: #d2d2d0;
  --line-dark: #bcbcb9;
  --accent: #a44f3c;
  --hover: #335577;
  --structure: #b21f56;
  --keyword: #7048b5;
  --operator: #7048b5;
  --control: #b54708;
  --type: #0067a3;
  --string: #287044;
  --number: #0b6e75;
  --comment: #777b82;
  --builtin: #8b3f84;
  --selection: #ccd9de;
  --ui: Helvetica, Arial, sans-serif;
  --book: QIJI, "Songti SC", "STSong", "Noto Serif CJK SC", serif;
  --mono: "SFMono-Regular", "Cascadia Code", "Noto Sans Mono CJK SC", monospace;
  --column: 34px;
}

* { box-sizing: border-box; }
html, body { width: 100%; height: 100%; margin: 0; overflow: hidden; }
body { color: var(--ink); background: var(--page); font: 16px/1.5 var(--ui); }
::selection { color: var(--ink); background: var(--selection); }

.state-toggle {
  position: fixed;
  width: 1px;
  height: 1px;
  opacity: 0;
  pointer-events: none;
}

.shell {
  height: 100%;
  display: grid;
  grid-template-rows: 68px minmax(0, 1fr);
  background: var(--page);
}

.masthead {
  position: relative;
  z-index: 20;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: 12px;
  padding: 8px 16px;
  border-bottom: 1px solid var(--line);
  background: #f7f7f6;
}
.identity { display: contents; }
.seal {
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  border: 1px solid var(--line-dark);
  border-radius: 7px;
  color: var(--ink);
  background: var(--paper);
  font: 28px/1 var(--book);
}
.title-group { justify-self: start; min-width: 0; text-align: left; }
h1 { margin: 0; color: var(--ink); font: 600 15px/1.25 var(--ui); }
h1 span { color: var(--ink-soft); font-size: 12px; font-weight: 400; }
.subtitle { margin: 3px 0 0; color: var(--ink-soft); font: 12px/1.25 var(--ui); }

.toolbar { display: flex; align-items: center; justify-content: flex-end; }
.tool-button {
  min-height: 32px;
  padding: 4px 10px;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  border: 1px solid var(--line-dark);
  border-radius: 2px;
  color: var(--ink-soft);
  background: rgba(255, 255, 255, .24);
  font-size: 14px;
  cursor: pointer;
  user-select: none;
}
.tool-button:hover { color: #000; border-color: var(--ink-soft); }
.tool-button:focus-visible, .tree-summary:focus-visible, .tree-link:focus-visible, .source-link:focus-visible {
  outline: 2px solid var(--hover);
  outline-offset: 2px;
}
.tool-icon { width: 16px; display: inline-grid; place-items: center; font: 14px/1 var(--ui); }
.horizontal-label { display: none; }
.vertical-label { display: inline; }
#writing-toggle:checked ~ .shell .writing-button { color: var(--ink); border-color: var(--ink-soft); background: var(--paper-deep); }
#writing-toggle:checked ~ .shell .horizontal-label { display: inline; }
#writing-toggle:checked ~ .shell .vertical-label { display: none; }

/* 常规左侧文件树；源码阅读区始终位于右侧。 */
.workspace {
  min-height: 0;
  display: grid;
  grid-template-columns: clamp(240px, 22vw, 340px) minmax(0, 1fr);
  grid-template-rows: minmax(0, 1fr);
}
.sidebar {
  position: relative;
  z-index: 12;
  min-width: 0;
  min-height: 0;
  display: grid;
  grid-template-rows: auto minmax(0, 1fr) auto;
  border-right: 1px solid var(--line);
  background: #f7f7f6;
}
.sidebar-head {
  padding: 14px 14px 10px;
  border-bottom: 1px solid var(--line);
}
.section-label {
  margin: 0;
  color: var(--ink);
  font: 600 13px/1.35 var(--ui);
}
.sidebar-note {
  margin: 3px 0 0;
  color: var(--ink-soft);
  font: 12px/1.35 var(--ui);
}
.sidebar-foot {
  min-width: 0;
  padding: 8px 12px;
  display: flex;
  justify-content: space-between;
  gap: 8px;
  border-top: 1px solid var(--line);
  color: var(--ink-soft);
  font: 11px/1.35 var(--ui);
}
.sidebar-foot span {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.tree {
  height: 100%;
  overflow: auto;
  padding: 4px 0;
  direction: ltr;
  scrollbar-width: thin;
  scrollbar-color: var(--line-dark) var(--page);
}
.tree ul { list-style: none; margin: 0; padding: 0; }
.tree > .tree-list {
  width: 100%;
  min-width: 0;
  display: block;
}
.tree > .tree-list > .tree-item {
  position: relative;
  width: 100%;
}
.tree details > summary { list-style: none; }
.tree details > summary::-webkit-details-marker { display: none; }
.tree-summary, .tree-link {
  min-height: 22px;
  margin: 0;
  padding: 0 6px;
  display: grid;
  grid-template-columns: 16px minmax(0, 1fr);
  align-items: center;
  gap: 3px;
  border: 1px solid transparent;
  border-radius: 0;
  color: var(--ink-soft);
  background: transparent;
  font: 13px/20px var(--ui);
  text-decoration: none;
  cursor: pointer;
}
.tree-summary .tree-name, .tree-link .tree-name { grid-column: 2; grid-row: 1; text-align: left; }
.tree-summary .node-icon, .tree-link .node-icon { grid-column: 1; grid-row: 1; }
.tree-summary:hover, .tree-link:hover,
.tree details[open] > .tree-summary {
  color: var(--ink);
  border-color: var(--line);
  background: var(--paper-deep);
}
.tree-link.is-default { color: var(--ink); background: var(--paper-deep); }
.tree-name { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.node-icon { position: relative; width: 15px; height: 16px; color: currentColor; }
.node-icon.folder::before { content: ""; position: absolute; inset: 5px 1px 1px; border: 1px solid currentColor; border-radius: 2px; }
.node-icon.folder::after { content: ""; position: absolute; left: 3px; top: 2px; width: 7px; height: 4px; border: 1px solid currentColor; border-bottom: 0; border-radius: 2px 2px 0 0; }
.node-icon.file::before { content: ""; position: absolute; inset: 1px 2px; border: 1px solid currentColor; border-radius: 1px; }
.node-icon.file::after { content: ""; position: absolute; left: 5px; top: 6px; width: 6px; height: 1px; background: currentColor; box-shadow: 0 3px currentColor, 0 6px currentColor; }

.tree > .tree-list > .directory-item > details > ul {
  position: static;
  display: block;
  padding-left: 12px;
}
.tree > .tree-list > .directory-item > details > ul ul { padding-left: 12px; }

.reader { grid-column: 2; min-width: 0; min-height: 0; background: var(--paper); }
.source-stack { position: relative; width: 100%; height: 100%; min-width: 0; min-height: 0; }
.source-document {
  position: absolute;
  inset: 0;
  z-index: 1;
  min-width: 0;
  min-height: 0;
  display: none;
  grid-template-columns: minmax(0, 1fr);
  grid-template-rows: minmax(0, 1fr);
  background: var(--page);
}
.source-document.is-default,
.source-document:target { display: grid; }
.source-document:target { z-index: 2; }

/* 竖排专注于正文；文件信息栏只在横排模式显示。 */
.reader-head {
  position: relative;
  grid-column: 2;
  grid-row: 1;
  min-width: 0;
  min-height: 0;
  margin: 12px 18px 14px 8px;
  padding: 0;
  display: none;
  grid-template-columns: 44px minmax(86px, 1fr) minmax(58px, .68fr);
  overflow: hidden;
  border: 2px solid var(--ink);
  background: var(--page);
}
.reader-head::before {
  content: "豫";
  grid-column: 2;
  grid-row: 1;
  display: grid;
  place-items: center;
  border-inline: 1px solid var(--ink);
  color: #080808;
  font: 112px/1 var(--book);
}
.path-block {
  grid-column: 3;
  grid-row: 1;
  min-width: 0;
  min-height: 0;
  padding: 14px 9px;
  display: flex;
  align-items: center;
  gap: 18px;
  overflow: hidden;
  writing-mode: vertical-rl;
  text-orientation: upright;
}
.breadcrumb {
  max-height: 74%;
  overflow: hidden;
  color: var(--ink);
  font: 19px/1.55 var(--book);
  letter-spacing: .12em;
}
.file-meta { display: none; }
.source-link {
  grid-column: 1;
  grid-row: 1;
  align-self: end;
  justify-self: center;
  margin-bottom: 14px;
  padding: 7px;
  border: 1px solid var(--accent);
  color: var(--accent);
  font: 18px/1 var(--book);
  text-decoration: none;
}
.source-link:hover { color: #000; border-color: #000; }

.code-viewport {
  grid-column: 1;
  grid-row: 1;
  min-width: 0;
  min-height: 0;
  overflow: auto;
  direction: rtl;
  overscroll-behavior: contain;
  border-top: 1px solid var(--line);
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background:
    repeating-linear-gradient(90deg, transparent 0, transparent calc(var(--column) - 1px), rgba(40, 40, 40, .10) calc(var(--column) - 1px), rgba(40, 40, 40, .10) var(--column)),
    var(--paper);
  scrollbar-color: var(--line-dark) var(--page);
}
.code-layout {
  min-width: 100%;
  min-height: 100%;
  width: max-content;
  height: 100%;
  display: flex;
  flex-direction: row-reverse;
  direction: ltr;
}
.line-numbers, .source-code {
  margin: 0;
  border: 0;
  tab-size: 4;
  font-variant-ligatures: none;
}
.line-numbers { display: none; }
.source-code {
  flex: 0 0 auto;
  width: max-content;
  height: 100%;
  min-height: 100%;
  padding: 14px 17px 28px;
  color: var(--ink);
  background: transparent;
  white-space: pre-wrap;
  overflow-wrap: anywhere;
  writing-mode: vertical-rl;
  text-orientation: upright;
  font: 18px/1.9 var(--book);
  letter-spacing: .055em;
}

/* 默认勾选横排模式，显示常规源码视图和行号。 */
#writing-toggle:checked ~ .shell .source-document {
  grid-template-columns: minmax(0, 1fr);
  grid-template-rows: 58px minmax(0, 1fr);
}
#writing-toggle:checked ~ .shell .reader-head {
  grid-column: 1;
  grid-row: 1;
  margin: 0;
  padding: 7px 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  overflow: visible;
  border: 0;
  border-bottom: 1px solid var(--line);
}
#writing-toggle:checked ~ .shell .reader-head::before { display: none; }
#writing-toggle:checked ~ .shell .path-block {
  min-width: 0;
  padding: 0;
  display: block;
  overflow: visible;
  writing-mode: horizontal-tb;
}
#writing-toggle:checked ~ .shell .breadcrumb {
  max-height: none;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  font: 14px/1.35 var(--mono);
  letter-spacing: 0;
}
#writing-toggle:checked ~ .shell .file-meta {
  display: block;
  max-height: none;
  margin-top: 2px;
  overflow: visible;
  font: 12px/1.35 var(--ui);
  letter-spacing: 0;
}
#writing-toggle:checked ~ .shell .source-link {
  align-self: auto;
  justify-self: auto;
  margin: 0;
  padding: 4px 8px;
  border: 0;
  color: var(--ink-soft);
  font: 16px/1 var(--book);
}
#writing-toggle:checked ~ .shell .code-viewport {
  grid-column: 1;
  grid-row: 2;
  border-top: 0;
  background: var(--paper);
  direction: ltr;
}
#writing-toggle:checked ~ .shell .code-layout {
  height: auto;
  display: grid;
  grid-template-columns: 58px minmax(max-content, 1fr);
}
#writing-toggle:checked ~ .shell .line-numbers {
  display: block;
  min-height: 100%;
  padding: 16px 10px 48px 5px;
  border-right: 1px solid var(--line);
  color: var(--ink-faint);
  background: var(--paper-deep);
  white-space: pre;
  text-align: right;
  font: 12px/1.7 var(--mono);
  user-select: none;
}
#writing-toggle:checked ~ .shell .source-code {
  min-width: 100%;
  min-height: 100%;
  width: auto;
  height: auto;
  padding: 16px 28px 48px 15px;
  background: var(--paper);
  white-space: pre;
  overflow-wrap: normal;
  writing-mode: horizontal-tb;
  text-orientation: mixed;
  font: 16px/1.7 var(--mono);
  letter-spacing: 0;
}

.tok-comment { color: var(--comment); }
.tok-string { color: var(--string); }
.tok-escape { color: #bd2c00; font-weight: 600; }
.tok-number { color: var(--number); }
.tok-keyword { color: var(--keyword); }
.tok-operator { color: var(--operator); }
.tok-control { color: var(--control); font-weight: 600; }
.tok-structure, .tok-structure-terminator { color: var(--structure); font-weight: 700; }
.tok-type { color: var(--type); font-weight: 600; }
.tok-builtin { color: var(--builtin); }
.tok-builtin-type { color: #007078; font-weight: 600; }
.tok-builtin-function { color: var(--builtin); }
.tok-builtin-constant { color: #9b4d14; }
.tok-label { color: var(--accent); }
.tok-binder { color: #136f63; font-weight: 600; }
.tok-identifier { color: var(--ink); }
.tok-punctuation { color: #73777e; }
.tok-plain { color: inherit; }

@media (max-width: 760px) {
  .shell { grid-template-rows: 62px minmax(0, 1fr); }
  .masthead { gap: 8px; padding: 7px 9px; }
  .seal { width: 38px; height: 38px; font-size: 25px; }
  .title-group { justify-self: start; }
  h1 span, .subtitle { display: none; }
  .toolbar { position: static; }
  .tool-button { min-height: 27px; padding-block: 2px; }
  .workspace { grid-template-columns: minmax(180px, 38vw) minmax(0, 1fr); grid-template-rows: minmax(0, 1fr); }
  .sidebar-head { padding: 10px; }
  .sidebar-note { display: none; }
  .tree { padding: 3px 0; }
  .tree-summary, .tree-link { min-height: 24px; padding: 1px 5px; font-size: 12px; line-height: 20px; }
  .sidebar-foot { padding: 6px 8px; }
  .source-document { grid-template-columns: minmax(0, 1fr); }
  .reader-head { margin: 7px 7px 8px 5px; grid-template-columns: 28px minmax(52px, 1fr) 45px; }
  .reader-head::before { font-size: 68px; }
  .path-block { padding: 8px 5px; }
  .breadcrumb { font-size: 14px; }
  .file-meta { display: none; }
  .source-link { margin-bottom: 8px; padding: 4px; font-size: 14px; }
  .source-code { padding: 10px 12px 20px; font-size: 16px; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; }
}