It appears you have a well-structured Git repository with various files, including SVG icons and HTML documents. Here's a brief overview:

backend/node_modules/csso/lib/index.js

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+import { version } from './version.js';
+import * as syntax from './syntax.js';
+import * as utils from './utils.js';
+
+const { parse, generate, compress } = syntax;
+
+function debugOutput(name, options, startTime, data) {
+    if (options.debug) {
+        console.error(`## ${name} done in %d ms\n`, Date.now() - startTime);
+    }
+
+    return data;
+}
+
+function createDefaultLogger(level) {
+    let lastDebug;
+
+    return function logger(title, ast) {
+        let line = title;
+
+        if (ast) {
+            line = `[${((Date.now() - lastDebug) / 1000).toFixed(3)}s] ${line}`;
+        }
+
+        if (level > 1 && ast) {
+            let css = generate(ast);
+
+            // when level 2, limit css to 256 symbols
+            if (level === 2 && css.length > 256) {
+                css = css.substr(0, 256) + '...';
+            }
+
+            line += `\n  ${css}\n`;
+        }
+
+        console.error(line);
+        lastDebug = Date.now();
+    };
+}
+
+function buildCompressOptions(options) {
+    options = { ...options };
+
+    if (typeof options.logger !== 'function' && options.debug) {
+        options.logger = createDefaultLogger(options.debug);
+    }
+
+    return options;
+}
+
+function runHandler(ast, options, handlers) {
+    if (!Array.isArray(handlers)) {
+        handlers = [handlers];
+    }
+
+    handlers.forEach(fn => fn(ast, options));
+}
+
+function minify(context, source, options) {
+    options = options || {};
+
+    const filename = options.filename || '<unknown>';
+    let result;
+
+    // parse
+    const ast = debugOutput('parsing', options, Date.now(),
+        parse(source, {
+            context,
+            filename,
+            positions: Boolean(options.sourceMap)
+        })
+    );
+
+    // before compress handlers
+    if (options.beforeCompress) {
+        debugOutput('beforeCompress', options, Date.now(),
+            runHandler(ast, options, options.beforeCompress)
+        );
+    }
+
+    // compress
+    const compressResult = debugOutput('compress', options, Date.now(),
+        compress(ast, buildCompressOptions(options))
+    );
+
+    // after compress handlers
+    if (options.afterCompress) {
+        debugOutput('afterCompress', options, Date.now(),
+            runHandler(compressResult, options, options.afterCompress)
+        );
+    }
+
+    // generate
+    if (options.sourceMap) {
+        result = debugOutput('generate(sourceMap: true)', options, Date.now(), (() => {
+            const tmp = generate(compressResult.ast, { sourceMap: true });
+
+            tmp.map._file = filename; // since other tools can relay on file in source map transform chain
+            tmp.map.setSourceContent(filename, source);
+
+            return tmp;
+        })());
+    } else {
+        result = debugOutput('generate', options, Date.now(), {
+            css: generate(compressResult.ast),
+            map: null
+        });
+    }
+
+    return result;
+}
+
+function minifyStylesheet(source, options) {
+    return minify('stylesheet', source, options);
+}
+
+function minifyBlock(source, options) {
+    return minify('declarationList', source, options);
+}
+
+export {
+    version,
+    utils,
+
+    // main methods
+    minifyStylesheet as minify,
+    minifyBlock,
+
+    // css syntax parser/walkers/generator/etc
+    syntax
+};