{"id":8169,"date":"2018-11-18T22:02:26","date_gmt":"2018-11-18T14:02:26","guid":{"rendered":"https:\/\/www.zhangxinxu.com\/wordpress\/?p=8169"},"modified":"2024-12-05T16:27:13","modified_gmt":"2024-12-05T08:27:13","slug":"css-background-color-font-auto-match","status":"publish","type":"post","link":"https:\/\/www.zhangxinxu.com\/wordpress\/2018\/11\/css-background-color-font-auto-match\/","title":{"rendered":"CSS\u6587\u5b57\u548c\u80cc\u666fcolor\u81ea\u52a8\u914d\u8272\u6280\u672f\u7b80\u4ecb"},"content":{"rendered":"<p>by <a href=\"https:\/\/www.zhangxinxu.com\/\">zhangxinxu<\/a> from <a href=\"https:\/\/www.zhangxinxu.com\/wordpress\/?p=8169\">https:\/\/www.zhangxinxu.com\/wordpress\/?p=8169<\/a><br \/>\n\u672c\u6587\u53ef\u5168\u6587\u8f6c\u8f7d\uff0c\u4e2a\u4eba\u7f51\u7ad9\u65e0\u9700\u6388\u6743\uff0c\u53ea\u8981\u4fdd\u7559\u539f\u4f5c\u8005\u3001\u51fa\u5904\u4ee5\u53ca\u6587\u4e2d\u94fe\u63a5\u5373\u53ef\uff0c\u4efb\u4f55\u7f51\u7ad9\u5747\u53ef\u6458\u8981\u805a\u5408\uff0c\u5546\u7528\u8bf7\u8054\u7cfb\u6388\u6743\u3002<\/p>\n<h3>\u4e00\u3001\u6587\u5b57\u548c\u80cc\u666f\u989c\u8272\u81ea\u52a8\u9002\u914d\u9884\u89c8<\/h3>\n<p>\u5982\u4e0bGIF\u793a\u610f\uff0c\u5f53\u6211\u4eec\u6309\u94ae\u80cc\u666f\u8272\u9010\u6e10\u53d8\u6de1\u7684\u65f6\u5019\uff0c\u6587\u5b57\u989c\u8272\u4e5f\u4ece\u539f\u6765\u7684\u767d\u8272\u53d8\u6210\u9ed1\u8272\u4e86\uff0c\u540c\u65f6\u8fb9\u6846\u4e5f\u663e\u793a\u51fa\u6765\u4e86\uff0c\u5176\u4e2d\u7684\u914d\u8272\u8f6c\u6362\u662f\u7eafCSS\u5b9e\u73b0\u7684\u3002<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"\/\/image.zhangxinxu.com\/image\/blog\/201811\/auto-color-button.gif\" width=\"228\" height=\"225\" alt=\"\u81ea\u52a8\u914d\u8272\u6309\u94ae\u793a\u610f\" class=\"alignnone size-medium\" \/><\/p>\n<p>\u60a8\u53ef\u4ee5\u72e0\u72e0\u5730\u70b9\u51fb\u8fd9\u91cc\uff1a<a href=\"https:\/\/www.zhangxinxu.com\/study\/201811\/switch-font-color-for-different-background.php\" rel=\"noopener\" target=\"_blank\">\u6309\u94ae\u6587\u5b57\u53ca\u8fb9\u6846\u989c\u8272\u968f\u7740\u80cc\u666f\u8272\u81ea\u52a8\u53d8\u5316demo<\/a><\/p>\n<p>\u62d6\u52a8R\uff0cG\uff0cB\u5bf9\u5e94\u6ed1\u5757\uff0c\u53ef\u4ee5\u770b\u5230\u6309\u94ae\u6587\u5b57\u989c\u8272\u4ee5\u53ca\u8fb9\u6846\u989c\u8272\uff0c\u4f1a\u81ea\u52a8\u6839\u636e\u80cc\u666f\u8272\u4e0d\u540c\u800c\u53d1\u751f\u53d8\u5316\u3002\u5177\u4f53\u8868\u73b0\u4e3a\uff1a<\/p>\n<ul>\n<li>\u6df1\u8272\u80cc\u666f\u4e0b\uff0c\u6587\u5b57\u767d\u8272\uff0c\u65e0\u8fb9\u6846\u3002<\/li>\n<li>\u6d45\u8272\u80cc\u666f\u4e0b\uff0c\u6587\u5b57\u9ed1\u8272\uff0c\u6709\u52a0\u6df1\u8fb9\u6846\uff0c\u4fbf\u4e8e\u548c\u5468\u56f4\u73af\u5883\u533a\u5206\u5f00\u3002<\/li>\n<\/ul>\n<p>\u8fd9\u79cd\u667a\u80fd\u5339\u914d\u662f\u7eafCSS\u5b9e\u73b0\u7684\uff0c\u4e3b\u8981\u662f\u4f7f\u7528CSS3 calc()\u8ba1\u7b97\uff0c\u4ee5\u53ca<a href=\"https:\/\/www.zhangxinxu.com\/wordpress\/2016\/11\/css-css3-variables-var\/\">CSS3\u539f\u751fvar\u53d8\u91cf<\/a>\u3002<\/p>\n<h3>\u4e8c\u3001\u914d\u8272\u4ee3\u7801\u5c55\u793a<\/h3>\n<p>HTML\u4ee3\u7801\u5f88\u7b80\u5355\uff0c\u5982\u4e0b\uff1a<\/p>\n<pre>&lt;button class=\"btn\"&gt;\u6211\u662f\u6309\u94ae&lt;\/button&gt;<\/pre>\n<p>\u91cd\u70b9\u548c\u96be\u70b9\u5728CSS\u90e8\u5206\uff1a<\/p>\n<pre>:root {\r\n  <span style=\"color:green;\">\/* \u5b9a\u4e49RGB\u53d8\u91cf *\/<\/span>\r\n  --red: 44;\r\n  --green: 135;\r\n  --blue: 255;\r\n  <span style=\"color:green;\">\/* \u6587\u5b57\u989c\u8272\u53d8\u8272\u7684\u4e34\u754c\u503c\uff0c\u5efa\u8bae0.5~0.6 *\/<\/span>\r\n  --threshold: 0.5;\r\n  <span style=\"color:green;\">\/* \u6df1\u8272\u8fb9\u6846\u51fa\u73b0\u7684\u4e34\u754c\u503c\uff0c\u8303\u56f40~1\uff0c\u63a8\u83500.8+*\/<\/span>\r\n  --border-threshold: 0.8;\r\n}\r\n\r\n.btn {\r\n  <span style=\"color:green;\">\/* \u6309\u94ae\u80cc\u666f\u8272\u5c31\u662f\u57fa\u672c\u80cc\u666f\u8272 *\/<\/span>\r\n  background: rgb(var(--red), var(--green), var(--blue));\r\n\r\n  <span style=\"color:green;\">\/** \r\n   * \u4f7f\u7528sRGB Luma\u65b9\u6cd5\u8ba1\u7b97\u7070\u5ea6\uff08\u53ef\u4ee5\u770b\u6210\u4eae\u5ea6\uff09\r\n   * \u7b97\u6cd5\u4e3a\uff1a\r\n   * lightness = (red * 0.2126 + green * 0.7152 + blue * 0.0722) \/ 255\r\n  *\/<\/span>\r\n  --r: calc(var(--red) * 0.2126);\r\n  --g: calc(var(--green) * 0.7152);\r\n  --b: calc(var(--blue) * 0.0722);\r\n  --sum: calc(var(--r) + var(--g) + var(--b));\r\n  --lightness: calc(var(--sum) \/ 255);\r\n  \r\n  <span style=\"color:green;\">\/* \u8bbe\u7f6e\u989c\u8272 *\/<\/span>\r\n  color: hsl(0, 0%, calc((var(--lightness) - var(--threshold)) * -999999%));\r\n  \r\n  <span style=\"color:green;\">\/* \u786e\u5b9a\u8fb9\u6846\u900f\u660e\u5ea6 *\/<\/span>\r\n  --border-alpha: calc((var(--lightness) - var(--border-threshold)) * 100);\r\n  <span style=\"color:green;\">\/* \u8bbe\u7f6e\u8fb9\u6846\u76f8\u5173\u6837\u5f0f *\/<\/span>\r\n  border: .2em solid;\r\n  border-color: rgba(calc(var(--red) - 50), calc(var(--green) - 50), calc(var(--blue) - 50), var(--border-alpha));\r\n}<\/pre>\n<p>\u4e4d\u4e00\u770b\uff0c\u72b9\u5982\u9e2d\u5b50\u542c\u96f7\u2014\u2014\u4e0d\u77e5\u6240\u4e91\uff0c\u5176\u5b9e\u4e0d\u590d\u6742\uff0c\u4e14\u5bb9\u6211\u5256\u6790\u4e0b\u5b9e\u73b0\u539f\u7406\u3002<\/p>\n<h3>\u4e09\u3001\u524d\u666f\u80cc\u666f\u81ea\u52a8\u914d\u8272\u539f\u7406<\/h3>\n<h4>1. CSS\u5c5e\u6027\u503c\u8303\u56f4\u6ea2\u51fa\u8fb9\u754c\u6e32\u67d3\u7279\u6027<\/h4>\n<p>CSS\u8fd9\u95e8\u8bed\u8a00\u6709\u4e2a\u5f88\u6709\u610f\u601d\u7684\u7279\u6027\uff0c\u5c31\u662fCSS\u5c5e\u6027\u503c\u8d85\u8fc7\u6b63\u5e38\u7684\u8303\u56f4\u7684\u65f6\u5019\uff0c\u53ea\u8981\u683c\u5f0f\u6b63\u786e\uff0c\u4e5f\u4f1a\u6e32\u67d3\uff0c\u800c\u6e32\u67d3\u7684\u503c\u5c31\u662f\u5408\u6cd5\u8fb9\u754c\u503c\u3002<\/p>\n<p>\u4e3e\u4e24\u4e2a\u677f\u6817\uff1a<\/p>\n<ol>\n<li><code>opacity<\/code>\u900f\u660e\u5ea6\u5c5e\u6027\u503c\u5408\u6cd5\u8303\u56f4\u662f0-1\uff0c\u4f46\u662f\uff0c\u4f60\u8bbe\u7f6e\u8d1f\u6570\uff0c\u6216\u8005\u6781\u5927\u503c\uff0c\u6d4f\u89c8\u5668\u4e5f\u80fd\u89e3\u6790\uff0c\u53ea\u662f\u8981\u4e48\u662f0\uff0c\u8981\u4e48\u662f1\u800c\u5df2\uff0c\u5982\u4e0b\uff1a\n<pre>.example {\r\n  opacity: -2;    <span style=\"color:green;\">\/* \u89e3\u6790\u4e3a 0, \u5b8c\u5168\u900f\u660e *\/<\/span>\r\n  opacity: -1;    <span style=\"color:green;\">\/* \u89e3\u6790\u4e3a 0, \u5b8c\u5168\u900f\u660e *\/<\/span>\r\n  opacity: 2;     <span style=\"color:green;\">\/* \u89e3\u6790\u4e3a 1, \u5b8c\u5168\u4e0d\u900f\u660e *\/<\/span>\r\n  opacity: 100;   <span style=\"color:green;\">\/* \u89e3\u6790\u4e3a 1, \u5b8c\u5168\u4e0d\u900f\u660e *\/<\/span>\r\n}<\/pre>\n<\/li>\n<li>\u8272\u503c\uff0c\u5982HSL\uff0cS\u548cL\u7684\u8303\u56f4\u90fd\u662f0%-100%\uff0c\u4f46\u662f\uff0c\u4f60\u8bbe\u7f6e\u8d1f\u6570\uff0c\u6216\u8005\u6781\u5927\u503c\uff0c\u6d4f\u89c8\u5668\u4e5f\u80fd\u89e3\u6790\uff0c\u53ea\u662f\u8981\u4e48\u662f0%\uff0c\u8981\u4e48\u662f100%\u800c\u5df2\uff0c\u5982\u4e0b\uff1a\n<pre>.example {\r\n  color: hsl(0, 0%, -100%);    <span style=\"color:green;\">\/* \u89e3\u6790\u4e3a hsl(0, 0%, 0%), \u9ed1\u8272 *\/<\/span>\r\n  color: hsl(0, 0%, 200%);     <span style=\"color:green;\">\/* \u89e3\u6790\u4e3a hsl(0, 0%, 100%), \u767d\u8272 *\/<\/span>\r\n}<\/pre>\n<\/li>\n<\/ol>\n<p>\u672c\u6587\u7684\u914d\u8272\u6280\u672f\u5c31\u6d3b\u7528\u4e86\u8fd9\u79cd\u8fb9\u754c\u6e32\u67d3\u7279\u6027\u3002<\/p>\n<h4>2. var\u53d8\u91cf\u4f20\u9012\u7ed9calc\u5b9e\u73b0\u590d\u6742\u8ba1\u7b97<\/h4>\n<p>\u6211\u4eec\u5bf9CSS\u4ee3\u7801\u4ece\u4e0a\u5f80\u4e0b\u9010\u4e2a\u5256\u6790\u4e0b\u3002<\/p>\n<p><strong>\u9996\u5148<\/strong>\uff0c\u5728:root\u6839\u9009\u62e9\u5668\u4e0a\u5b9a\u4e49\u51e0\u4e2a\u5168\u5c40CSS\u53d8\u91cf\uff08\u8bed\u4e49\u4e0a\u7684\u5168\u5c40\uff09\uff1a<\/p>\n<pre>:root {\r\n  --red: 44;\r\n  --green: 135;\r\n  --blue: 255;\r\n\r\n  --threshold: 0.5;\r\n  --border-threshold: 0.8;\r\n}<\/pre>\n<p>\u5176\u4e2d\uff1a<\/p>\n<dl>\n<dt>&#8211;threshold<\/dt>\n<dd>\u8fd9\u4e2a\u662fcolor\u53d8\u8272\u7684\u4e34\u754c\u503c\uff0c\u7528\u6765\u548c\u5f53\u524dRGB\u989c\u8272\u503c\u7684\u4eae\u5ea6\u5bf9\u6bd4\u3002<\/dd>\n<dt>&#8211;border-threshold<\/dt>\n<dd>\u8fd9\u4e2a\u662f\u8fb9\u6846\u989c\u8272\u900f\u660e\u5ea6\u7684\u4e34\u754c\u503c\uff0c\u540c\u6837\u4e5f\u662f\u548c\u5f53\u524dRGB\u989c\u8272\u503c\u7684\u4eae\u5ea6\u5bf9\u6bd4\u3002<\/dd>\n<\/dl>\n<p><strong>\u7136\u540e<\/strong>\u662f<code>.btn{}<\/code>\u5185\u90e8\u7684CSS\u4ee3\u7801\uff1a<\/p>\n<ol>\n<li>\n<pre>background: rgb(var(--red), var(--green), var(--blue));<\/pre>\n<p>\u8fd9\u4e2a\u5f88\u597d\u7406\u89e3\uff0c\u5c31\u662f\u57fa\u672c\u7684RGB\u8272\u503c\u4f5c\u4e3a\u80cc\u666f\u8272\u3002<\/li>\n<li>\n<pre>--r: calc(var(--red) * 0.2126);\r\n--g: calc(var(--green) * 0.7152);\r\n--b: calc(var(--blue) * 0.0722);\r\n--sum: calc(var(--r) + var(--g) + var(--b));\r\n--lightness: calc(var(--sum) \/ 255);<\/pre>\n<p>\u8fd9\u91cc5\u884c5\u4e2aCSS\u53d8\u91cf\uff0c\u9700\u8981\u7684\u5176\u5b9e\u662f\u6700\u540e\u4e00\u4e2a<code>--lightness<\/code>\uff0c\u5c31\u662f\u8ba1\u7b97\u5f53\u524d\u80cc\u666f\u8272\u7684\u4eae\u5ea6\u3002\u7528\u7684\u662f\u4f7f\u7528sRGB Luma\u7070\u5ea6\u7b97\u6cd5<sup>\u2460<\/sup>\uff0c\u4e3a\u4ec0\u4e48\u9700\u89815\u884c\u5462\uff1f\u56e0\u4e3a\u8ba1\u7b97\u516c\u5f0f\u5c31\u662f\u5982\u6b64\uff1a<\/p>\n<pre>lightness = (red * 0.2126 + green * 0.7152 + blue * 0.0722) \/ 255<\/pre>\n<p>\u5176\u4e2d\uff0cR\uff0cG\uff0cB\u8272\u503c\u76f8\u4e58\u7684\u7cfb\u6570\u5c31\u662f\u56fa\u5b9a\u7684\uff0c\u4e0d\u540c\u7070\u5ea6\u7b97\u6cd5\u7cfb\u6570\u8fd8\u4e0d\u4e00\u6837\u3002<code>--lightness<\/code>\u8868\u793a\u4eae\u5ea6\uff0c\u8303\u56f4\u662f0-1\uff0c\u6b64\u65f6\u5c31\u53ef\u4ee5\u548c<code>--threshold<\/code>\u548c<code>--border-threshold<\/code>\u8fd9\u4e24\u4e2a\u4e34\u754c\u503c\u6bd4\u5bf9\uff0c\u6765\u786e\u5b9a\u6309\u94ae\u7684\u6587\u5b57\u989c\u8272\uff0c\u8fb9\u6846\u900f\u660e\u5ea6\u3002<\/p>\n<blockquote><p>\u2460 \u8fd9\u91cc\u7684\u7070\u5ea6\u53ef\u4ee5\u770b\u6210\u662f\u4eae\u5ea6\uff0c\u5b9e\u9645\u4e0aHSL\u7684\u4eae\u5ea6\u8ba1\u7b97\u65b9\u6cd5\u5e94\u8be5\u662f\uff0cR\uff0cG\uff0cB\u4e2d\u7684\u8272\u503c\u6700\u5927\u503c\u548c\u6700\u5c0f\u503c\u4e4b\u548c\u7684\u4e8c\u5206\u4e4b\u4e00\u3002<\/p><\/blockquote>\n<\/li>\n<li>\n<pre>color: hsl(0, 0%, calc((var(--lightness) - var(--threshold)) * -999999%))<\/pre>\n<p>\u8bbe\u7f6e\u989c\u8272\u7684CSS\u4ee3\u7801\u3002<\/p>\n<p>\u6b64\u5904<code>calc<\/code>\u8ba1\u7b97\u7ffb\u8bd1\u6210\u4e2d\u6587\u5c31\u662f\uff1a\uff08\u4eae\u5ea6\u503c &#8211; \u4e34\u754c\u503c\uff09 * \u6bd4\u4f8b\u7cfb\u6570\u3002<\/p>\n<p>\u5176\u4e2d\u4eae\u5ea6\u503c\u57280-1\u4e4b\u95f4\u6e38\u8d70\uff0c\u4e34\u754c\u503c\u662f\u56fa\u5b9a\u76840.5\uff0c\u4e8e\u662f\uff1a<\/p>\n<ul>\n<li>\u5982\u679c\u4eae\u5ea6\u503c\u5c0f\u4e8e0.5\uff0c\u4eae\u5ea6\u503c\u51cf\u53bb\u4e34\u754c\u503c\u4e3a\u8d1f\uff0c\u7531\u4e8e\u6211\u4eec\u7684\u6bd4\u4f8b\u7cfb\u6570\u662f\u5f88\u5927\u5f88\u5927\u7684\u8d1f\u6570\uff0c\u8d1f\u8d1f\u5f97\u6b63\uff0c\u4e8e\u662f\uff0c\u4f1a\u5f97\u5230\u4e00\u4e2a\u5de8\u5927\u7684\u6b63\u6570\uff0c\u6309\u7167\u8fb9\u754c\u6e32\u67d3\u539f\u7406\uff0c\u4f1a\u6309\u7167100%\u6e32\u67d3\uff0c\u4e8e\u662f\u989c\u8272\u662f\u767d\u8272\uff1b<\/li>\n<li>\u5982\u679c\u4eae\u5ea6\u503c\u5927\u4e8e0.5\uff0c\u4eae\u5ea6\u503c\u51cf\u53bb\u4e34\u754c\u503c\u4e3a\u6b63\uff0c\u7531\u4e8e\u6211\u4eec\u7684\u6bd4\u4f8b\u7cfb\u6570\u662f\u5f88\u5927\u5f88\u5927\u7684\u8d1f\u6570\uff0c\u4e8e\u662f\uff0c\u4f1a\u5f97\u5230\u4e00\u4e2a\u5de8\u5927\u7684\u8d1f\u6570\uff0c\u6309\u7167\u8fb9\u754c\u6e32\u67d3\u539f\u7406\uff0c\u4f1a\u6309\u71670%\u6e32\u67d3\uff0c\u4e8e\u662f\u989c\u8272\u662f\u9ed1\u8272\uff1b<\/li>\n<\/ul>\n<p>\u4ee5\u4e0a\u5c31\u662f\u6309\u94ae\u6587\u5b57\u989c\u8272\u53d8\u8272\u80cc\u666f\u4e0b\u9ed1\u8272\uff0c\u6df1\u8272\u80cc\u666f\u4e0b\u767d\u8272\u7684\u539f\u7406\u3002<\/li>\n<li>\n<pre>--border-alpha: calc((var(--lightness) - var(--border-threshold)) * 100);<\/pre>\n<p>\u8fb9\u6846\u900f\u660e\u5ea6\u662f\u7c7b\u4f3c\u7684\u539f\u7406\u3002\u6b64\u5904<code>calc<\/code>\u8ba1\u7b97\u7ffb\u8bd1\u6210\u4e2d\u6587\u5c31\u662f\uff1a\uff08\u4eae\u5ea6\u503c &#8211; \u8fb9\u6846\u4e34\u754c\u503c\uff09 * 100\u3002<\/p>\n<p>\u5176\u4e2d\u4eae\u5ea6\u503c\u57280-1\u4e4b\u95f4\u6e38\u8d70\uff0c\u8fb9\u6846\u4e34\u754c\u503c\u662f\u56fa\u5b9a\u76840.8\uff0c\u4e8e\u662f\uff1a<\/p>\n<ul>\n<li>\u5982\u679c\u4eae\u5ea6\u503c\u5c0f\u4e8e0.8\uff0c\u4eae\u5ea6\u503c\u51cf\u53bb\u8fb9\u6846\u4e34\u754c\u503c\u4e3a\u8d1f\uff0c\u5728CSS\u4e2d\uff0c\u8d1f\u6570\u900f\u660e\u5ea6\u4f1a\u6309\u7167\u8fb9\u754c0\u6e32\u67d3\uff0c\u6b64\u65f6\u8fb9\u6846\u5b8c\u5168\u900f\u660e\uff1b<\/li>\n<li>\u5982\u679c\u4eae\u5ea6\u503c\u5927\u4e8e0.8\uff0c\u4eae\u5ea6\u503c\u51cf\u53bb\u8fb9\u6846\u4e34\u754c\u503c\u4e3a\u6b63\uff0c\u6b64\u65f6\u7684\u900f\u660e\u5ea6\u8ba1\u7b97\u503c\u4f1a\u57280~20\u4e4b\u95f4\u6e38\u8d70\uff0c\u5f53\u7136\uff0c\u6570\u503c\u5927\u4e8e1\u7684\u900f\u660e\u5ea6\u503c\u90fd\u4f1a\u6309\u71671\u6e32\u67d3\uff0c\u6b64\u65f6\uff0c\u8fb9\u6846\u57fa\u672c\u5904\u4e8e\u5b8c\u5168\u4e0d\u900f\u660e\u72b6\u6001\uff0c\u52a0\u6df1\u7684\u8fb9\u6846\u663e\u73b0\uff1b<\/li>\n<\/ul>\n<\/li>\n<li>\n<pre>border: .2em solid;\r\nborder-color: rgba(calc(var(--red) - 50), calc(var(--green) - 50), calc(var(--blue) - 50), var(--border-alpha));<\/pre>\n<p>\u8bbe\u7f6e\u8fb9\u6846\u6837\u5f0f\uff0c\u8fb9\u6846\u989c\u8272\u6bd4\u80cc\u666f\u8272\u6df150\u4e2a\u5355\u4f4d\u503c\uff08\u8d1f\u6570\u4e3a\u6309\u71670\u6e32\u67d3\uff09\uff0c\u7136\u540e\u900f\u660e\u5ea6\u5c31\u662f\u57fa\u4e8e\u4eae\u5ea6\u52a8\u6001\u8ba1\u7b97\u7684\u3002\u6df1\u8272\u80cc\u666f\u4e0b\uff0c\u6309\u94ae\u8fb9\u6846\u900f\u660e\u5ea6\u4e3a0\uff0c\u4e0d\u663e\u793a\uff1b\u6d45\u8272\u80cc\u666f\u4e0b\uff0c\u900f\u660e\u5ea6\u57280~1\u4e4b\u95f4\u6e38\u8d70\uff0c\u51fa\u73b0\uff0c\u5317\u4eac\u989c\u8272\u8d8a\u6d45\uff0c\u8fb9\u6846\u900f\u660e\u5ea6\u8d8a\u5927\uff0c\u8fb9\u6846\u989c\u8272\u8d8a\u6df1\uff0c\u7b26\u5408\u914d\u8272\u9884\u671f\u3002<\/li>\n<\/ol>\n<p>\u76f8\u4fe1\u7ecf\u8fc7\u4e0a\u9762\u7684\u4e00\u756a\u5256\u6790\uff0c\u5927\u5bb6\u5c31\u4f1a\u660e\u767d\u5176\u5b9e\u73b0\u7684\u539f\u7406\u4e86\u3002<\/p>\n<p><strong>\u6539\u53d8\u6309\u94ae\u7684\u80cc\u666f\u8272<\/strong><\/p>\n<p>.btn\u7c7b\u540d\u4e0b\u7684CSS\u4ee3\u7801\u662f\u56fa\u5b9a\u7684\uff0c\u8ba9\u6211\u4eec\u9700\u8981\u6539\u53d8\u6309\u94ae\u7684\u989c\u8272\u7684\u65f6\u5019\uff0c\u4e0d\u662f\u6539.btn\u4e0b\u7684CSS\uff0c\u800c\u662f\u4fee\u6539:root\u4e2d\u7684\u4e0b\u97623\u4e2a\u53d8\u91cf\u503c\uff1a<\/p>\n<pre>--red: 44;\r\n--green: 135;\r\n--blue: 255;<\/pre>\n<p>CSS\u8bbe\u7f6e\u76f4\u63a5\u6539\u6570\u503c\uff0c\u5982\u679c\u662fJS\u8bbe\u7f6e\uff0c\u501f\u52a9<code>setProperty()<\/code>\u65b9\u6cd5\uff0c\u82e5\u4e0d\u4e86\u89e3\uff0c\u53ef\u4ee5\u53c2\u8003\u8fd9\u7bc7\u6587\u7ae0\uff1a\u201c<a href=\"https:\/\/www.zhangxinxu.com\/wordpress\/?p=8163\">\u5982\u4f55HTML\u6807\u7b7e\u548cJS\u4e2d\u8bbe\u7f6eCSS3 var\u53d8\u91cf<\/a>\u201d\u3002<\/p>\n<h3>\u56db\u3001\u6700\u540e\u7ed3\u675f\u8bed<\/h3>\n<p>\u7531\u4e8evar\u7684\u517c\u5bb9\u6027\u9650\u5236\uff0c\u8fd9\u4e2a\u975e\u5e38\u6709\u610f\u601d\u7684CSS\u6280\u5de7\u8fd8\u4e0d\u592a\u9002\u5408\u5728\u5927\u578b\u5bf9\u5916\u9879\u76ee\u4e2d\u4f7f\u7528\u3002<\/p>\n<p>\u5c0f\u7a0b\u5e8f\u53ef\u4ee5\u4e00\u8bd5\uff0c\u56e0\u4e3a\u5185\u6838\u73af\u5883\u76f8\u5bf9\u56fa\u5b9a\u3002\u5185\u90e8\u7cfb\u7edf\uff0c\u5b9e\u9a8c\u9879\u76ee\u53ef\u4ee5\u73a9\u4e00\u73a9\uff0c\u4f1a\u5f88\u6709\u610f\u601d\u3002<\/p>\n<p>\u8fd9\u79cd\u914d\u8272\u6280\u5de7\u5176\u5b9e\u4e0d\u4ec5\u53ef\u4ee5\u7528\u5728\u6309\u94ae\u4e0a\uff0c\u4e00\u4e9b\u5927\u533a\u57df\u7684\u5e03\u5c40\u4e5f\u662f\u53ef\u4ee5\u7528\u7684\uff0c\u56e0\u4e3a\u8fd9\u4e9b\u5e03\u5c40\u7684\u80cc\u666f\u8272\u53ef\u80fd\u662f\u52a8\u6001\u7684 \uff0c\u6b64\u65f6\uff0c\u6587\u5b57\u989c\u8272\u7684\u914d\u8272\u4e5f\u53ef\u4ee5\u501f\u52a9CSS\u5b9e\u73b0\u81ea\u52a8\u5316\u3002<\/p>\n<p>\u53e6\u5916\uff0c\u672c\u6587demo\u4e2d\u6309\u94ae\u6587\u5b57\u5c31\u9ed1\u767d\u4e24\u8272\uff0c\u5b9e\u9645\u4e0a\uff0c\u6211\u4eec\u7684\u76f8\u4e58\u7cfb\u6570\u5c0f\u4e00\u70b9\u7684\u8bdd\uff0c\u53ef\u4ee5\u6709\u66f4\u591a\u7684\u8272\u503c\u51fa\u73b0\uff0c\u914d\u8272\u4f1a\u66f4\u52a0\u7cbe\u81f4\u3002<\/p>\n<p><strong>\u53c2\u8003\u6587\u7ae0<\/strong><\/p>\n<ul>\n<li><a href=\"https:\/\/css-tricks.com\/switch-font-color-for-different-backgrounds-with-css\/\" rel=\"noopener nofollow\" target=\"_blank\">Switch font color &#8230; CSS<\/a><\/li>\n<\/ul>\n<p>\u4ee5\u4e0a\u5c31\u662f\u672c\u6587\u5168\u90e8\u5185\u5bb9\uff0c\u611f\u8c22\u9605\u8bfb\uff01<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"\/\/image.zhangxinxu.com\/image\/emtion\/emoji\/1f603.svg\" width=\"20\" height=\"20\" align=\"absmiddle\"><\/p>\n<p>\u672c\u6587\u4e3a\u539f\u521b\u6587\u7ae0\uff0c\u4f1a\u7ecf\u5e38\u66f4\u65b0\u77e5\u8bc6\u70b9\u4ee5\u53ca\u4fee\u6b63\u4e00\u4e9b\u9519\u8bef\uff0c\u56e0\u6b64\u8f6c\u8f7d\u8bf7\u4fdd\u7559\u539f\u51fa\u5904\uff0c\u65b9\u4fbf\u6eaf\u6e90\uff0c\u907f\u514d\u9648\u65e7\u9519\u8bef\u77e5\u8bc6\u7684\u8bef\u5bfc\uff0c\u540c\u65f6\u6709\u66f4\u597d\u7684\u9605\u8bfb\u4f53\u9a8c\u3002<br \/>\n\u672c\u6587\u5730\u5740\uff1a<a href=\"https:\/\/www.zhangxinxu.com\/wordpress\/?p=8169\">https:\/\/www.zhangxinxu.com\/wordpress\/?p=8169<\/a><\/p>\n<p>\uff08\u672c\u7bc7\u5b8c\uff09<\/p>\n","protected":false},"excerpt":{"rendered":"<p><img loading=\"lazy\" decoding=\"async\" src=\"\/\/image.zhangxinxu.com\/image\/blog\/201811\/auto-color-button2.gif\" width=\"161\" height=\"100\" alt=\"\u667a\u80fd\u914d\u8272\" class=\"alignright size-medium\" \/><\/p>\n<p>CSS\u8d8a\u6765\u8d8a\u5f3a\uff0c\u73b0\u5728\u5df2\u7ecf\u53ef\u4ee5\u5b9e\u73b0\u6839\u636e\u4e0d\u540c\u7684\u80cc\u666f\u8272\u663e\u793a\u4e0d\u540c\u7684\u524d\u666f\u8272\u8fdb\u884c\u5339\u914d\u4e86\uff0c\u4f8b\u5982\u53f3\u56feGIF\u56fe\u7247\u6240\u793a\uff0c\u80cc\u666f\u8272\u4e00\u5f00\u59cb\u6df1\u8272\uff0c\u6587\u5b57\u989c\u8272\u4e3a\u767d\u8272\uff0c\u5f53\u80cc\u666f\u8272\u9010\u6e10\u53d8\u6de1\u7684\u65f6\u5019\uff0c\u6587\u5b57\u989c\u8272\u4e5f\u4ece\u539f\u6765\u7684\u767d\u8272\u53d8\u6210\u9ed1\u8272\u4e86\uff0c\u540c\u65f6\u8fb9\u6846\u4e5f\u663e\u793a\u51fa\u6765\u4e86\uff0c\u4ee5\u4fbf\u6709\u66f4\u597d\u7684\u8bc6\u522b\u5ea6\u3002\u5982\u4f55\u5b9e\u73b0\u7684\u5462\uff1f\u53bb\u6587\u4e2d\u4e00\u63a2\u7a76\u7adf\u5427~<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[389,971,177,1271,1177,398,337,1089,503,188,251],"_links":{"self":[{"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/posts\/8169"}],"collection":[{"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/comments?post=8169"}],"version-history":[{"count":3,"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/posts\/8169\/revisions"}],"predecessor-version":[{"id":11488,"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/posts\/8169\/revisions\/11488"}],"wp:attachment":[{"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/media?parent=8169"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/categories?post=8169"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/tags?post=8169"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}