add initial marp implementation with sample content and build configuration

node_modules/@marp-team/marpit/lib/postcss/advanced_background.js

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+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.default = exports.advancedBackground = void 0;
+var _postcss_plugin = _interopRequireDefault(require("../helpers/postcss_plugin"));
+function _interopRequireDefault(e) { return e && e.__esModule ? e : { default: e }; }
+/** @module */
+
+/**
+ * Marpit PostCSS advanced background plugin.
+ *
+ * Append style to suport the advanced background.
+ *
+ * @function advancedBackground
+ */
+const advancedBackground = exports.advancedBackground = (0, _postcss_plugin.default)('marpit-postcss-advanced-background', () => css => {
+  css.last.after(`
+section[data-marpit-advanced-background="background"] {
+  columns: initial !important;
+  display: block !important;
+  padding: 0 !important;
+}
+
+section[data-marpit-advanced-background="background"]::before,
+section[data-marpit-advanced-background="background"]::after,
+section[data-marpit-advanced-background="content"]::before,
+section[data-marpit-advanced-background="content"]::after {
+  display: none !important;
+}
+
+section[data-marpit-advanced-background="background"] > div[data-marpit-advanced-background-container] {
+  all: initial;
+  display: flex;
+  flex-direction: row;
+  height: 100%;
+  overflow: hidden;
+  width: 100%;
+}
+
+section[data-marpit-advanced-background="background"] > div[data-marpit-advanced-background-container][data-marpit-advanced-background-direction="vertical"] {
+  flex-direction: column;
+}
+
+section[data-marpit-advanced-background="background"][data-marpit-advanced-background-split] > div[data-marpit-advanced-background-container] {
+  width: var(--marpit-advanced-background-split, 50%);
+}
+
+section[data-marpit-advanced-background="background"][data-marpit-advanced-background-split="right"] > div[data-marpit-advanced-background-container] {
+  margin-left: calc(100% - var(--marpit-advanced-background-split, 50%));
+}
+
+section[data-marpit-advanced-background="background"] > div[data-marpit-advanced-background-container] > figure {
+  all: initial;
+  background-position: center;
+  background-repeat: no-repeat;
+  background-size: cover;
+  flex: auto;
+  margin: 0;
+}
+
+section[data-marpit-advanced-background="background"] > div[data-marpit-advanced-background-container] > figure > figcaption {
+	position: absolute;
+  border: 0;
+  clip: rect(0, 0, 0, 0);
+  height: 1px;
+  margin: -1px;
+  overflow: hidden;
+  padding: 0;
+  white-space: nowrap;
+  width: 1px;
+}
+
+section[data-marpit-advanced-background="content"],
+section[data-marpit-advanced-background="pseudo"] {
+  background: transparent !important;
+}
+
+section[data-marpit-advanced-background="pseudo"],
+:marpit-container > svg[data-marpit-svg] > foreignObject[data-marpit-advanced-background="pseudo"] {
+  pointer-events: none !important;
+}
+
+section[data-marpit-advanced-background-split] {
+  width: 100%;
+  height: 100%;
+}
+`.trim());
+});
+var _default = exports.default = advancedBackground;

node_modules/@marp-team/marpit/lib/postcss/container_query.js

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+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.postprocess = exports.default = exports.containerQuery = void 0;
+var _cssesc = _interopRequireDefault(require("cssesc"));
+var _postcss_plugin = _interopRequireDefault(require("../helpers/postcss_plugin"));
+function _interopRequireDefault(e) { return e && e.__esModule ? e : { default: e }; }
+/** @module */
+
+const reservedNames = ['none', 'inherit', 'initial', 'revert', 'revert-layer', 'unset'];
+const marpitContainerQueryPseudoMatcher = /\bsection:marpit-container-query\b/g;
+
+/**
+ * Marpit PostCSS container query plugin.
+ *
+ * Add support of container queries for child elements of the `section` element.
+ * (`@container` at-rule, and `cqw` `cqh` `cqi` `cqb` `cqmin` `cqmax` units)
+ *
+ * @function meta
+ * @param {string|string[]} [containerName=undefined] Container name
+ * @param {boolean} [escape=true] Set whether to escape container name
+ */
+const containerQuery = exports.containerQuery = (0, _postcss_plugin.default)('marpit-postcss-container-query', (containerName = undefined, escape = true) => css => {
+  const containerNames = (Array.isArray(containerName) ? containerName : [containerName]).filter(name => name && !reservedNames.includes(name));
+  const containerNameDeclaration = containerNames.length > 0 ? `\n  container-name: ${containerNames.map(name => escape ? (0, _cssesc.default)(name.toString(), {
+    isIdentifier: true
+  }) : name.toString()).join(' ')};` : '';
+  const style = `
+section:marpit-container-query {
+  container-type: size;${containerNameDeclaration}
+}
+`.trim();
+  if (css.first) {
+    css.first.before(style);
+  } else {
+    css.append(style);
+  }
+});
+const postprocess = exports.postprocess = (0, _postcss_plugin.default)('marpit-postcss-container-query-postprocess', () => css => css.walkRules(marpitContainerQueryPseudoMatcher, rule => {
+  rule.selectors = rule.selectors.map(selector => selector.replace(marpitContainerQueryPseudoMatcher, ':where(section)'));
+}));
+var _default = exports.default = containerQuery;

node_modules/@marp-team/marpit/lib/postcss/import/hoisting.js

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+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.importHoisting = exports.default = void 0;
+var _postcss_plugin = _interopRequireDefault(require("../../helpers/postcss_plugin"));
+function _interopRequireDefault(e) { return e && e.__esModule ? e : { default: e }; }
+/** @module */
+
+/**
+ * Marpit PostCSS import hoisting plugin.
+ *
+ * Hoist `@charset` and `@import` at-rule to the beginning of CSS. Marpit is
+ * manipulating CSS with many PostCSS plugins, so sometimes a few at-rules
+ * cannot keep specification.
+ *
+ * This plugin takes care of hoisting for invalid at-rules.
+ *
+ * @function importHoisting
+ */
+const importHoisting = exports.importHoisting = (0, _postcss_plugin.default)('marpit-postcss-import-hoisting', () => css => {
+  const hoisted = {
+    charset: undefined,
+    imports: []
+  };
+  css.walkAtRules(rule => {
+    if (rule.name === 'charset') {
+      rule.remove();
+      if (!hoisted.charset) hoisted.charset = rule;
+    } else if (rule.name === 'import') {
+      hoisted.imports.push(rule.remove());
+    }
+  });
+  const {
+    first
+  } = css
+
+  // Hoist at-rules
+  ;
+  [hoisted.charset, ...hoisted.imports].filter(r => r).forEach((rule, idx) => {
+    // Strip whitespace from the beginning of first at-rule
+    const prependRule = idx === 0 ? rule.clone({
+      raws: {
+        before: undefined
+      }
+    }) : rule;
+    first.before(prependRule);
+  });
+});
+var _default = exports.default = importHoisting;

node_modules/@marp-team/marpit/lib/postcss/import/parse.js

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+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.importParse = exports.default = void 0;
+var _postcss_plugin = _interopRequireDefault(require("../../helpers/postcss_plugin"));
+function _interopRequireDefault(e) { return e && e.__esModule ? e : { default: e }; }
+/** @module */
+
+/**
+ * @typedef {object} ImportMeta
+ * @prop {AtRule} node The at-rule node parsed by PostCSS.
+ * @prop {string} value The specified value.
+ */
+
+/**
+ * Marpit PostCSS import parse plugin.
+ *
+ * Parse `@import` and `@import-theme` rules that specify a plain string.
+ *
+ * The `@import` rule for Marpit theme follows CSS spec. It must precede all
+ * other statements. (excepted `@charset`)
+ *
+ * When you are using CSS preprocessors like Sass, `@import` would resolve path
+ * in compiling and would be lost definition. So you can use `@import-theme`
+ * rule alternatively.
+ *
+ * A specification of `@import-theme` has a bit different from `@import`. You
+ * can place `@import-theme` rule at any in the CSS root, and the content of
+ * imported theme will always append to the beginning of CSS.
+ *
+ * @function importParse
+ */
+const importParse = exports.importParse = (0, _postcss_plugin.default)('marpit-postcss-import-parse', () => (css, {
+  result
+}) => {
+  const imports = {
+    import: [],
+    importTheme: []
+  };
+  let allowImport = true;
+  css.walk(node => {
+    if (node.type === 'atrule') {
+      const push = target => {
+        const [quote] = node.params;
+        if (quote !== '"' && quote !== "'") return;
+        const splitedValue = node.params.slice(1).split(quote);
+        let value = '';
+        splitedValue.every(v => {
+          if (v.endsWith('\\')) {
+            value = `${value}${v.slice(0, -1)}${quote}`;
+            return true;
+          }
+          value = `${value}${v}`;
+          return false;
+        });
+        node.marpitImportParse = value;
+        target.push({
+          node,
+          value
+        });
+      };
+      if (allowImport) {
+        if (node.name === 'import') {
+          push(imports.import);
+        } else if (node.name !== 'charset') {
+          allowImport = false;
+        }
+      }
+      if (node.name === 'import-theme' && node.parent.type === 'root') {
+        push(imports.importTheme);
+      }
+    } else if (node.type !== 'comment') {
+      allowImport = false;
+    }
+  });
+  result.marpitImport = [...imports.importTheme, ...imports.import];
+});
+var _default = exports.default = importParse;

node_modules/@marp-team/marpit/lib/postcss/import/replace.js

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+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.importReplace = exports.default = void 0;
+var _postcss_plugin = _interopRequireDefault(require("../../helpers/postcss_plugin"));
+var _parse = _interopRequireDefault(require("./parse"));
+function _interopRequireDefault(e) { return e && e.__esModule ? e : { default: e }; }
+/** @module */
+
+/**
+ * Marpit PostCSS import replace plugin.
+ *
+ * Replace parsed `@import` / `@import-theme` rules.
+ *
+ * Please see {@link module:postcss/import/parse} about the specification of
+ * each syntax.
+ *
+ * @function importReplace
+ * @param {ThemeSet} themeSet ThemeSet instance.
+ */
+const importReplace = (themeSet, importedThemes = []) => (0, _postcss_plugin.default)('marpit-postcss-import-replace', () => ({
+  plugins: [(0, _parse.default)(), (0, _postcss_plugin.default)('marpit-postcss-import-replace-processor', () => (css, {
+    postcss
+  }) => {
+    const prepends = [];
+    css.walk(node => {
+      const name = node.marpitImportParse;
+      if (name) {
+        const theme = themeSet.get(name);
+        if (theme) {
+          if (importedThemes.includes(name)) throw new Error(`Circular "${name}" theme import is detected.`);
+          const processed = postcss([importReplace(themeSet, [...importedThemes, name])]).process(theme.css);
+          if (node.name === 'import') {
+            node.replaceWith(processed.root);
+          } else {
+            node.remove();
+            prepends.unshift(processed.root);
+          }
+        }
+      }
+    });
+    for (const root of prepends) css.first.before(root);
+  })()]
+}));
+exports.importReplace = importReplace;
+var _default = exports.default = importReplace;

node_modules/@marp-team/marpit/lib/postcss/import/suppress.js

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+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.importSuppress = exports.default = void 0;
+var _postcss_plugin = _interopRequireDefault(require("../../helpers/postcss_plugin"));
+var _parse = _interopRequireDefault(require("./parse"));
+function _interopRequireDefault(e) { return e && e.__esModule ? e : { default: e }; }
+/** @module */
+
+/**
+ * Marpit PostCSS import suppress plugin.
+ *
+ * Comment out `@import` / `@import-theme` rules that have imported theme.
+ *
+ * This plugin is useful to prevent the inline style's rolled-up theme import by
+ * unexpected order.
+ *
+ * @function importSuppress
+ * @param {ThemeSet} themeSet ThemeSet instance.
+ */
+const importSuppress = exports.importSuppress = (0, _postcss_plugin.default)('marpit-postcss-import-suppress', themeSet => ({
+  plugins: [(0, _parse.default)(), (0, _postcss_plugin.default)('marpit-postcss-import-suppress', () => css => {
+    css.walk(node => {
+      if (node.marpitImportParse && themeSet.has(node.marpitImportParse)) node.replaceWith(`${node.raw('before')}/* ${node.toString()}; */`);
+    });
+  })()]
+}));
+var _default = exports.default = importSuppress;

node_modules/@marp-team/marpit/lib/postcss/meta.js

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+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.meta = exports.default = void 0;
+var _postcss_plugin = _interopRequireDefault(require("../helpers/postcss_plugin"));
+function _interopRequireDefault(e) { return e && e.__esModule ? e : { default: e }; }
+/** @module */
+
+/**
+ * Marpit PostCSS meta plugin.
+ *
+ * Parse CSS comment written in the format of `@key value`.
+ *
+ * @function meta
+ * @param {Object} [opts]
+ * @param {Object} [opts.metaType] An object for defined types for metadata.
+ */
+const meta = exports.meta = (0, _postcss_plugin.default)('marpit-postcss-meta', (opts = {}) => (css, {
+  result
+}) => {
+  const metaType = opts.metaType || {};
+  result.marpitMeta = result.marpitMeta || {};
+  css.walkComments(comment => {
+    comment.text.slice(0).replace(/^[*!\s]*@([\w-]+)\s+(.+)$/gim, (_, metaName, value) => {
+      if (metaType[metaName] === Array) {
+        // Array meta
+        result.marpitMeta[metaName] = [...(result.marpitMeta[metaName] || []), value];
+      } else {
+        // String meta (default)
+        result.marpitMeta[metaName] = value;
+      }
+    });
+  });
+});
+var _default = exports.default = meta;

node_modules/@marp-team/marpit/lib/postcss/nesting.js

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+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.nesting = exports.default = void 0;
+var _postcssIsPseudoClass = _interopRequireDefault(require("@csstools/postcss-is-pseudo-class"));
+var _postcssNesting = _interopRequireDefault(require("postcss-nesting"));
+var _postcss_plugin = _interopRequireDefault(require("../helpers/postcss_plugin"));
+function _interopRequireDefault(e) { return e && e.__esModule ? e : { default: e }; }
+/** @module */
+
+const {
+  Rule: applyPostCSSNesting
+} = (0, _postcssNesting.default)();
+const matcher = /:is\((?:section|:root)\b/;
+const nesting = exports.nesting = (0, _postcss_plugin.default)('marpit-postcss-nesting', () => (root, helpers) => {
+  const rules = [];
+
+  // Note: Use walk instead of walkRules to include nested rules
+  root.walk(node => {
+    if (node.type !== 'rule') return;
+    rules.push(node);
+    node.__marpitNestingOriginalSelector = node.selector;
+  });
+
+  // Apply postcss-nesting
+  root.walkRules(rule => applyPostCSSNesting(rule, helpers));
+  const {
+    Rule: applyPostCSSIsPseudoClass
+  } = (0, _postcssIsPseudoClass.default)({
+    onComplexSelector: 'warning'
+  }).prepare();
+  for (const rule of rules) {
+    if (rule.__marpitNestingOriginalSelector !== rule.selector && matcher.test(rule.selector)) {
+      // Apply postcss-is-pseudo-class only to transformed rules that is
+      // including `:is() selector starting from `section` element or `:root`
+      // pseudo-class
+      applyPostCSSIsPseudoClass(rule, helpers);
+    }
+    delete rule.__marpitNestingOriginalSelector;
+  }
+});
+var _default = exports.default = nesting;

node_modules/@marp-team/marpit/lib/postcss/pagination.js

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+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.pagination = exports.default = void 0;
+var _postcss_plugin = _interopRequireDefault(require("../helpers/postcss_plugin"));
+function _interopRequireDefault(e) { return e && e.__esModule ? e : { default: e }; }
+/** @module */
+
+/**
+ * Marpit PostCSS pagination plugin.
+ *
+ * Marpit uses `section::after` to show the pagination on each slide. It defines
+ * in the scaffold theme.
+ *
+ * This plugin will comment out a `content` declaration defined in any
+ * `section::after` of the root, to prevent override the defined attribute for
+ * paginating.
+ *
+ * @function pagination
+ */
+const pagination = exports.pagination = (0, _postcss_plugin.default)('marpit-postcss-pagination', () => css => {
+  css.walkRules(rule => {
+    if (rule.selectors.some(selector => /^section(?![\w-])[^\s>+~]*::?after$/.test(selector.replace(/\[.*?\]/g, '')))) rule.walkDecls('content', decl => {
+      if (!decl.value.includes('attr(data-marpit-pagination)')) decl.replaceWith(`${decl.raw('before')}/* ${decl.toString()}; */`);
+    });
+  });
+});
+var _default = exports.default = pagination;

node_modules/@marp-team/marpit/lib/postcss/printable.js

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+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.printable = exports.postprocess = exports.default = void 0;
+var _postcss_plugin = _interopRequireDefault(require("../helpers/postcss_plugin"));
+function _interopRequireDefault(e) { return e && e.__esModule ? e : { default: e }; }
+/** @module */
+
+const marpitPrintContainerStyle = `
+html, body {
+  background-color: #fff;
+  margin: 0;
+  page-break-inside: avoid;
+  break-inside: avoid-page;
+}
+`.trim();
+
+/**
+ * Marpit PostCSS printable plugin.
+ *
+ * Make printable slide deck as PDF.
+ *
+ * @param {Object} opts
+ * @param {string} opts.width
+ * @param {string} opts.height
+ * @function printable
+ */
+const printable = exports.printable = (0, _postcss_plugin.default)('marpit-postcss-printable', opts => css => {
+  css.walkAtRules('media', rule => {
+    if (rule.params === 'marpit-print') rule.remove();
+  });
+  css.first.before(`
+@page {
+  size: ${opts.width} ${opts.height};
+  margin: 0;
+}
+
+@media marpit-print {
+  section {
+    page-break-before: always;
+    break-before: page;
+  }
+
+  section, section * {
+    -webkit-print-color-adjust: exact !important;
+    animation-delay: 0s !important;
+    animation-duration: 0s !important;
+    color-adjust: exact !important;
+    print-color-adjust: exact !important;
+    transition: none !important;
+  }
+
+  :marpit-container > svg[data-marpit-svg] {
+    display: block;
+    height: 100vh;
+    width: 100vw;
+  }
+}
+`.trim());
+});
+
+/**
+ * The post-process PostCSS plugin of Marpit printable plugin.
+ *
+ * @function postprocess
+ */
+const postprocess = exports.postprocess = (0, _postcss_plugin.default)('marpit-postcss-printable-postprocess', () => css => css.walkAtRules('media', rule => {
+  if (rule.params !== 'marpit-print') return;
+  rule.params = 'print';
+  rule.first.before(marpitPrintContainerStyle);
+}));
+var _default = exports.default = printable;

node_modules/@marp-team/marpit/lib/postcss/pseudo_selector/prepend.js

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+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.pseudoSelectorPrepend = exports.default = void 0;
+var _postcss_plugin = _interopRequireDefault(require("../../helpers/postcss_plugin"));
+function _interopRequireDefault(e) { return e && e.__esModule ? e : { default: e }; }
+/** @module */
+
+/**
+ * Marpit PostCSS pseudo selector prepending plugin.
+ *
+ * Prepend `:marpit-container > :marpit-slide` pseudo selector to each selector
+ * of Marpit theme CSS for modulized styling.
+ *
+ * @function pseudoSelectorPrepend
+ */
+const pseudoSelectorPrepend = exports.pseudoSelectorPrepend = (0, _postcss_plugin.default)('marpit-postcss-pseudo-selector-prepend', () => css => css.walkRules(rule => {
+  const {
+    type,
+    name
+  } = rule.parent || {};
+  if (type === 'atrule' && name === 'keyframes') return;
+  rule.selectors = rule.selectors.map(selector => {
+    if (/^section(?![\w-])/.test(selector)) return `:marpit-container > :marpit-slide${selector.slice(7)}`;
+    if (selector.startsWith(':marpit-container')) return selector;
+    return `:marpit-container > :marpit-slide ${selector}`;
+  });
+}));
+var _default = exports.default = pseudoSelectorPrepend;

node_modules/@marp-team/marpit/lib/postcss/pseudo_selector/replace.js

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+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.pseudoSelectorReplace = exports.default = void 0;
+var _cssesc = _interopRequireDefault(require("cssesc"));
+var _postcss_plugin = _interopRequireDefault(require("../../helpers/postcss_plugin"));
+var _wrap_array = require("../../helpers/wrap_array");
+function _interopRequireDefault(e) { return e && e.__esModule ? e : { default: e }; }
+/** @module */
+
+const buildSelector = elms => elms.map(e => {
+  const classes = new Set((e.class || '').split(/\s+/).filter(c => c));
+  let element = [e.tag, ...classes].map(c => (0, _cssesc.default)(c, {
+    isIdentifier: true
+  })).join('.');
+  if (e.id) element += `#${(0, _cssesc.default)(e.id, {
+    isIdentifier: true
+  })}`;
+  return element;
+}).join(' > ');
+
+/**
+ * Marpit PostCSS pseudo selector replace plugin.
+ *
+ * Replace `:marpit-container` and `:marpit-slide` pseudo selector into
+ * container element(s).
+ *
+ * @function pseudoSelectorReplace
+ * @param {Element|Element[]} [elements] Container elements
+ * @param {Element|Element[]} [slideElements={ tag: 'section' }] Slide elements
+ */
+const pseudoSelectorReplace = exports.pseudoSelectorReplace = (0, _postcss_plugin.default)('marpit-postcss-pseudo-selector-replace', (elements, slideElements = {
+  tag: 'section'
+}) => {
+  const container = buildSelector([...(0, _wrap_array.wrapArray)(elements)]);
+  const section = buildSelector([...(0, _wrap_array.wrapArray)(slideElements)]);
+  return css => css.walkRules(rule => {
+    rule.selectors = rule.selectors.map(selector => selector.replace(/:marpit-container(?![\w-])/g, container).replace(/:marpit-slide(?![\w-])/g, section).replace(/^\s*>\s*/, ''));
+  });
+});
+var _default = exports.default = pseudoSelectorReplace;

node_modules/@marp-team/marpit/lib/postcss/root/font_size.js

@@ -0,0 +1,49 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.rootFontSizeCustomProp = exports.rootFontSize = exports.default = void 0;
+var _postcss_plugin = _interopRequireDefault(require("../../helpers/postcss_plugin"));
+function _interopRequireDefault(e) { return e && e.__esModule ? e : { default: e }; }
+/** @module */
+
+const rootFontSizeCustomProp = exports.rootFontSizeCustomProp = '--marpit-root-font-size';
+
+/**
+ * Marpit PostCSS root font size plugin.
+ *
+ * Inject CSS variable based on the root slide container `section` for correct
+ * calculation of `rem` unit in the context of Marpit.
+ *
+ * @function rootFontSize
+ */
+const rootFontSize = exports.rootFontSize = (0, _postcss_plugin.default)('marpit-postcss-root-font-size', () => (css, postcss) => css.walkRules(rule => {
+  const injectSelector = new Set();
+  for (const selector of rule.selectors) {
+    // Detect whether the selector is targeted to section
+    const parentSelectors = selector.split(/(\s+|\s*[>~+]\s*)/);
+    const targetSelector = parentSelectors.pop();
+    const delimiterMatched = targetSelector.match(/[.:#[]/);
+    const target = delimiterMatched ? targetSelector.slice(0, delimiterMatched.index) : targetSelector;
+    if (target === 'section' || target.endsWith('*') || target === '') {
+      // Generate selector for injection
+      injectSelector.add([...parentSelectors, target === 'section' ? 'section' : ':marpit-container > :marpit-slide section',
+      // Universal selector is targeted to the children `section` of root `section`
+      delimiterMatched ? targetSelector.slice(delimiterMatched.index) : ''].join(''));
+    }
+  }
+  if (injectSelector.size === 0) return;
+
+  // Inject CSS variable
+  const injectRule = postcss.rule({
+    selectors: [...injectSelector.values()]
+  });
+  rule.walkDecls('font-size', decl => {
+    injectRule.append(decl.clone({
+      prop: rootFontSizeCustomProp
+    }));
+  });
+  if (injectRule.nodes.length > 0) rule.parent.insertAfter(rule, injectRule);
+}));
+var _default = exports.default = rootFontSize;

node_modules/@marp-team/marpit/lib/postcss/root/increasing_specificity.js

@@ -0,0 +1,27 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.rootIncreasingSpecificity = exports.pseudoClass = exports.default = void 0;
+var _postcss_plugin = _interopRequireDefault(require("../../helpers/postcss_plugin"));
+function _interopRequireDefault(e) { return e && e.__esModule ? e : { default: e }; }
+/** @module */
+
+const pseudoClass = exports.pseudoClass = ':marpit-root';
+const matcher = new RegExp(`\\b(?:section)?${pseudoClass}\\b`, 'g');
+
+/**
+ * Marpit PostCSS root increasing specificity plugin.
+ *
+ * Replace specific pseudo-class selector to `:where(section):not([\20 root])`,
+ * to increase specificity. `:marpit-root` is always added to `section` selector
+ * by root replace plugin so `:where(section):not([\20 root])` must always match
+ * too (HTML does not allow U+0020 SPACE in the attribute name.).
+ *
+ * @function rootIncreasingSpecificity
+ */
+const rootIncreasingSpecificity = exports.rootIncreasingSpecificity = (0, _postcss_plugin.default)('marpit-postcss-root-increasing-specificity', () => css => css.walkRules(rule => {
+  rule.selectors = rule.selectors.map(selector => selector.replace(matcher, ':where(section):not([\\20 root])'));
+}));
+var _default = exports.default = rootIncreasingSpecificity;

node_modules/@marp-team/marpit/lib/postcss/root/rem.js

@@ -0,0 +1,27 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.rem = exports.default = void 0;
+var _postcss_plugin = _interopRequireDefault(require("../../helpers/postcss_plugin"));
+var _font_size = require("./font_size");
+function _interopRequireDefault(e) { return e && e.__esModule ? e : { default: e }; }
+/** @module */
+
+const skipParsingMatcher = /("[^"]*"|'[^']*'|(?:attr|url|var)\([^)]*\))/g;
+
+/**
+ * Marpit PostCSS rem plugin.
+ *
+ * Replace `rem` unit to calculated value from CSS variable.
+ *
+ * @function rem
+ */
+const rem = exports.rem = (0, _postcss_plugin.default)('marpit-postcss-rem', () => css => css.walkDecls(decl => {
+  decl.value = decl.value.split(skipParsingMatcher).map((v, i) => {
+    if (i % 2) return v;
+    return v.replace(/(\d*\.?\d+)rem\b/g, (_, num) => `calc(var(${_font_size.rootFontSizeCustomProp}, 1rem) * ${num})`);
+  }).join('');
+}));
+var _default = exports.default = rem;

node_modules/@marp-team/marpit/lib/postcss/root/replace.js

@@ -0,0 +1,26 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.rootReplace = exports.default = void 0;
+var _postcss_plugin = _interopRequireDefault(require("../../helpers/postcss_plugin"));
+function _interopRequireDefault(e) { return e && e.__esModule ? e : { default: e }; }
+/** @module */
+
+/**
+ * Marpit PostCSS root replace plugin.
+ *
+ * Replace `:root` pseudo-class selector into `section`. It can add custom
+ * pseudo class through `pseudoClass` option to make distinguishable from
+ * `section` selector.
+ *
+ * @function rootReplace
+ */
+const rootReplace = exports.rootReplace = (0, _postcss_plugin.default)('marpit-postcss-root-replace', ({
+  pseudoClass
+} = {}) => css => css.walkRules(rule => {
+  // Replace `:root` pseudo-class selectors into `section`
+  rule.selectors = rule.selectors.map(selector => selector.replace(/(^|[\s>+~(])(?:section)?:root\b/g, (_, s) => `${s}section${pseudoClass || ''}`));
+}));
+var _default = exports.default = rootReplace;

node_modules/@marp-team/marpit/lib/postcss/section_size.js

@@ -0,0 +1,56 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.sectionSize = exports.default = void 0;
+var _postcss_plugin = _interopRequireDefault(require("../helpers/postcss_plugin"));
+function _interopRequireDefault(e) { return e && e.__esModule ? e : { default: e }; }
+/** @module */
+
+/**
+ * Marpit PostCSS section size plugin.
+ *
+ * Parse width and height declartaion on `section` selector.
+ *
+ * @function sectionSize
+ */
+const sectionSize = exports.sectionSize = (0, _postcss_plugin.default)('marpit-postcss-section-size', ({
+  preferedPseudoClass
+} = {}) => {
+  const rootSectionMatcher = new RegExp(`^section${preferedPseudoClass ? `(${preferedPseudoClass})?` : ''}$`);
+  return (css, {
+    result
+  }) => {
+    const originalSize = result.marpitSectionSize || {};
+    const detectedSize = {};
+    const preferedSize = {};
+    let matched;
+    css.walkRules(rule => {
+      if (rule.selectors.some(s => {
+        matched = s.match(rootSectionMatcher);
+        return !!matched;
+      })) {
+        rule.walkDecls(/^(width|height)$/, decl => {
+          const {
+            prop
+          } = decl;
+          const value = decl.value.trim();
+          if (matched[1]) {
+            preferedSize[prop] = value;
+          } else {
+            detectedSize[prop] = value;
+          }
+        });
+      }
+    });
+    const width = preferedSize.width || detectedSize.width || originalSize.width;
+    const height = preferedSize.height || detectedSize.height || originalSize.height;
+    result.marpitSectionSize = {
+      ...originalSize
+    };
+    if (width) result.marpitSectionSize.width = width;
+    if (height) result.marpitSectionSize.height = height;
+  };
+});
+var _default = exports.default = sectionSize;

node_modules/@marp-team/marpit/lib/postcss/svg_backdrop.js

@@ -0,0 +1,74 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.svgBackdrop = exports.default = void 0;
+var _postcss_plugin = _interopRequireDefault(require("../helpers/postcss_plugin"));
+function _interopRequireDefault(e) { return e && e.__esModule ? e : { default: e }; }
+/** @module */
+
+const backdropMatcher = /(?:\b|^)::backdrop$/;
+
+/**
+ * Marpit PostCSS SVG backdrop plugin.
+ *
+ * Retarget `::backdrop` and `section::backdrop` selector to
+ * `@media screen { :marpit-container > svg[data-marpit-svg] { .. } }`. It means
+ * `::backdrop` targets the SVG container in inline SVG mode.
+ *
+ * It's useful for setting style of the letterbox and pillarbox in the SVG
+ * scaled slide.
+ *
+ * ```css
+ * ::backdrop {
+ *   background-color: #448;
+ * }
+ * ```
+ *
+ * The original definition will remain to support an original usage of
+ * `::backdrop`.
+ *
+ * The important differences from an original `::backdrop` are following:
+ *
+ * - In original spec, `::backdrop` creates a separated layer from the target
+ *   element, but Marpit's `::backdrop` does not. The slide elements still
+ *   become the child of `::backdrop` so setting some properties that are
+ *   inherited may make broken slide rendering.
+ * - Even if the browser is not fullscreen, `::backdrop` will match to SVG
+ *   container whenever matched to `@media screen` media query.
+ *
+ * If concerned to conflict with the style provided by the app, consider to
+ * disable the selector support by `inlineSVG: { backdropSelector: false }`.
+ *
+ * @see https://developer.mozilla.org/docs/Web/CSS/::backdrop
+ * @function svgBackdrop
+ */
+const svgBackdrop = exports.svgBackdrop = (0, _postcss_plugin.default)('marpit-postcss-svg-backdrop', () => (css, postcss) => {
+  css.walkRules(rule => {
+    const injectSelectors = new Set();
+    for (const selector of rule.selectors) {
+      // Detect pseudo-element (must appear after the simple selectors)
+      if (!selector.match(backdropMatcher)) continue;
+
+      // Detect whether the selector is targeted to section
+      const delimiterMatched = selector.match(/[.:#[]/); // must match
+      const target = selector.slice(0, delimiterMatched.index);
+      if (target === 'section' || target === '') {
+        const delimiter = selector.slice(delimiterMatched.index, -10);
+        injectSelectors.add(`:marpit-container > svg[data-marpit-svg]${delimiter}`);
+      }
+    }
+    if (injectSelectors.size > 0 && rule.nodes.length > 0) {
+      rule.parent.insertAfter(rule, postcss.atRule({
+        name: 'media',
+        params: 'screen',
+        nodes: [postcss.rule({
+          selectors: [...injectSelectors.values()],
+          nodes: rule.nodes
+        })]
+      }));
+    }
+  });
+});
+var _default = exports.default = svgBackdrop;