{"id":2733,"date":"2025-08-19T02:22:22","date_gmt":"2025-08-19T02:22:22","guid":{"rendered":"https:\/\/satokotadesign.com\/blog\/?p=2733"},"modified":"2025-08-19T02:22:42","modified_gmt":"2025-08-19T02:22:42","slug":"starry-sky-animation","status":"publish","type":"post","link":"https:\/\/satokotadesign.com\/blog\/starry-sky-animation\/","title":{"rendered":"CSS\u3068JavaScript\u3067\u4f5c\u308b\u661f\u7a7a\u30a2\u30cb\u30e1\u30fc\u30b7\u30e7\u30f3\uff5c\u30e9\u30f3\u30c0\u30e0\u306b\u70b9\u6ec5\u3059\u308b\u591c\u7a7a\u306e\u5b9f\u88c5\u65b9\u6cd5"},"content":{"rendered":"<p>\u3053\u3093\u306b\u3061\u306f\uff01\u9759\u5ca1\u770c\u6d5c\u677e\u5e02\u3067WEB\u30c7\u30b6\u30a4\u30ca\u30fc\u3092\u3057\u3066\u3044\u307e\u3059\u5c0f\u7027\u3067\u3059\u3002<\/p>\n<p>Web\u30b5\u30a4\u30c8\u306e\u80cc\u666f\u6f14\u51fa\u3068\u3057\u3066\u4eba\u6c17\u306e\u9ad8\u3044\u300c\u591c\u7a7a\u306e\u661f\u30a2\u30cb\u30e1\u30fc\u30b7\u30e7\u30f3\u300d\u3002<br \/>\n\u9759\u6b62\u3057\u305f\u80cc\u666f\u753b\u50cf\u3088\u308a\u3082\u3001<span class=\"sc_marker-animation\">\u661f\u304c\u30e9\u30f3\u30c0\u30e0\u306b\u70b9\u6ec5\u3057\u3066\u3044\u308b\u3060\u3051\u3067\u30da\u30fc\u30b8\u5168\u4f53\u304c\u30b0\u30c3\u3068\u83ef\u3084\u304b\u306b\u306a\u308a\u307e\u3059\u3002<\/span><br \/>\n\u4eca\u56de\u306f CSS\u3068\u5c11\u3057\u306eJavaScript \u3092\u7d44\u307f\u5408\u308f\u305b\u3066\u300c\u661f\u304c\u30e9\u30f3\u30c0\u30e0\u306b\u304d\u3089\u3081\u304f\u591c\u7a7a\u300d\u3092\u4f5c\u308b\u65b9\u6cd5\u3092\u3054\u7d39\u4ecb\u3057\u307e\u3059\u3002<\/p>\n<h2 class=\"sc_heading bborder b blue\"><span class=\"sc_title\" >\u5b8c\u6210\u30a4\u30e1\u30fc\u30b8<\/span><\/h2>\n<div class=\"sc_designlist ol radius solid blue\">\n<ol>\n<li>\u80cc\u666f\u5168\u4f53\u304c\u591c\u7a7a\u306e\u30b0\u30e9\u30c7\u30fc\u30b7\u30e7\u30f3<\/li>\n<li>\u661f\u306f\u30e9\u30f3\u30c0\u30e0\u306a\u4f4d\u7f6e\u306b\u914d\u7f6e<\/li>\n<li>\u70b9\u6ec5\u901f\u5ea6\u30fb\u30bf\u30a4\u30df\u30f3\u30b0\u30fb\u30b5\u30a4\u30ba\u304c\u7570\u306a\u308b\u3053\u3068\u3067\u81ea\u7136\u306b\u898b\u3048\u308b<\/li>\n<li>\u305f\u307e\u306b\u6d41\u308c\u661f\u3082\u6d41\u308c\u308b<\/li>\n<\/ol>\n<\/div>\n<p>\u5b9f\u969b\u306b\u52d5\u304b\u3059\u3068\u3001\u5e7b\u60f3\u7684\u306a\u96f0\u56f2\u6c17\u3092\u4f53\u9a13\u3067\u304d\u307e\u3059\u3088\u3002<\/p>\n<h2 class=\"sc_heading solid blue\"><span class=\"sc_title\" >\u30c7\u30e2\u30b3\u30fc\u30c9<\/span><\/h2>\n<p class=\"codepen\" data-height=\"300\" data-default-tab=\"html,result\" data-slug-hash=\"GgpQeJw\" data-pen-title=\"Untitled\" data-user=\"ekwwawpb-the-styleful\" style=\"height: 300px; box-sizing: border-box; display: flex; align-items: center; justify-content: center; border: 2px solid; margin: 1em 0; padding: 1em;\">\n  <span>See the Pen <a href=\"https:\/\/codepen.io\/ekwwawpb-the-styleful\/pen\/GgpQeJw\"><br \/>\n  Untitled<\/a> by \u5c0f\u7027\u8ce2 (<a href=\"https:\/\/codepen.io\/ekwwawpb-the-styleful\">@ekwwawpb-the-styleful<\/a>)<br \/>\n  on <a href=\"https:\/\/codepen.io\">CodePen<\/a>.<\/span>\n<\/p>\n<p><script async src=\"https:\/\/public.codepenassets.com\/embed\/index.js\"><\/script><\/p>\n<h2 class=\"sc_heading solid blue\"><span class=\"sc_title\" >\u57fa\u672c\u306eHTML<\/span><\/h2>\n<p>\u307e\u305a\u306f\u661f\u7a7a\u3092\u63cf\u753b\u3059\u308b\u305f\u3081\u306e\u30d9\u30fc\u30b9\u8981\u7d20\u3092\u7528\u610f\u3057\u307e\u3059\u3002<\/p>\n<pre class=\"line-numbers\" ><code class=\"language-markup\">&lt;div class=&quot;sky&quot;&gt;&lt;\/div&gt;\r\n&lt;footer class=&quot;credits&quot;&gt;CSS Twinkling Stars Demo&lt;\/footer&gt;<\/code><\/pre>\n<p>\u3053\u3053\u3067\u306f<span class=\"fontbackground\" style=\"background:;\"> .sky <\/span>\u30b3\u30f3\u30c6\u30ca\u5185\u306b JavaScript \u3067\u661f\uff08<span class=\"fontbackground\" style=\"background:;\">\uff1cspan class=\"star\"\uff1e<\/span>\uff09\u3092\u81ea\u52d5\u751f\u6210\u3059\u308b\u4ed5\u7d44\u307f\u3092\u4f5c\u308a\u307e\u3059\u3002<\/p>\n<h2 class=\"sc_heading solid blue\"><span class=\"sc_title\" >CSS\u3067\u591c\u7a7a\u3068\u661f\u3092\u30c7\u30b6\u30a4\u30f3<\/span><\/h2>\n<p>\u6b21\u306b\u3001\u591c\u7a7a\u306e\u80cc\u666f\u3068\u661f\u306e\u30b9\u30bf\u30a4\u30eb\u3092CSS\u3067\u6307\u5b9a\u3057\u307e\u3059\u3002<\/p>\n<pre class=\"line-numbers\" ><code class=\"language-css\">:root {\r\n  --hue: 230;\r\n  --sky-from: hsl(var(--hue) 35% 6%);\r\n  --sky-to:   hsl(var(--hue) 55% 12%);\r\n}\r\n\r\nbody {\r\n  margin: 0;\r\n  background: radial-gradient(1200px 600px at 50% -20%, var(--sky-to), var(--sky-from) 60%) fixed;\r\n  overflow: hidden;\r\n}\r\n\r\n.sky {\r\n  position: fixed;\r\n  inset: 0;\r\n}\r\n\r\n.star {\r\n  position: absolute;\r\n  border-radius: 50%;\r\n  background: radial-gradient(circle, rgba(255,255,255,.95) 0 40%, rgba(255,255,255,0) 70%);\r\n  opacity: var(--base-opacity, .65);\r\n  animation: twinkle var(--twinkle, 2.2s) ease-in-out infinite;\r\n  animation-delay: calc(var(--delay, 0s) * -1);\r\n}\r\n\r\n@keyframes twinkle {\r\n  0%, 100% { opacity: .6; transform: scale(1); }\r\n  40%      { opacity: .2; }\r\n  70%      { opacity: 1; transform: scale(1.1); }\r\n}\r\n<\/code><\/pre>\n<p>\u3053\u3053\u3067\u306f\u661f\u3092\u5186\u5f62\u306e<span class=\"fontbackground\" style=\"background:;\"> radial-gradient <\/span>\u3067\u63cf\u304d\u3001<span class=\"fontbackground\" style=\"background:;\">@keyframes<\/span> \u3067\u900f\u660e\u5ea6\u3092\u5909\u3048\u308b\u3053\u3068\u3067\u70b9\u6ec5\u30a2\u30cb\u30e1\u30fc\u30b7\u30e7\u30f3\u3092\u5b9f\u73fe\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n<h2 class=\"sc_heading solid blue\"><span class=\"sc_title\" >JavaScript\u3067\u661f\u3092\u30e9\u30f3\u30c0\u30e0\u306b\u914d\u7f6e<\/span><\/h2>\n<p>\u661f\u306e\u6570\u3084\u4f4d\u7f6e\u3001\u70b9\u6ec5\u306e\u30bf\u30a4\u30df\u30f3\u30b0\u3092\u30e9\u30f3\u30c0\u30e0\u5316\u3059\u308b\u3053\u3068\u3067\u3001\u3088\u308a\u81ea\u7136\u306a\u591c\u7a7a\u3092\u8868\u73fe\u3057\u307e\u3059\u3002<\/p>\n<pre class=\"line-numbers\" ><code class=\"language-js\">const sky = document.querySelector(&#039;.sky&#039;);\r\nconst STAR_COUNT = 220;\r\n\r\nconst rand = (min, max) =&gt; Math.random() * (max - min) + min;\r\n\r\nfor (let i = 0; i &lt; STAR_COUNT; i++) {\r\n  const star = document.createElement(&#039;span&#039;);\r\n  star.className = &#039;star&#039;;\r\n\r\n  star.style.left = `${rand(0, 100)}%`;\r\n  star.style.top  = `${rand(0, 100)}%`;\r\n  star.style.width = star.style.height = `${rand(1, 3)}px`;\r\n\r\n  star.style.setProperty(&#039;--base-opacity&#039;, rand(0.35, 0.9));\r\n  star.style.setProperty(&#039;--twinkle&#039;, `${rand(1.6, 3.8)}s`);\r\n  star.style.setProperty(&#039;--delay&#039;, `${rand(0, 4)}s`);\r\n\r\n  sky.appendChild(star);\r\n}\r\n<\/code><\/pre>\n<p>\u3053\u308c\u3067\u3001\u661f\u304c\u81ea\u7136\u306a\u9593\u9694\u3067\u70b9\u6ec5\u3059\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n<h2 class=\"sc_heading solid blue\">\n\t\t<span class=\"sc_title\" >\u6d41\u308c\u661f\u3092\u52a0\u3048\u3066\u307f\u308b<\/span><br \/>\n\t<\/h2>\n<p class=\"codepen\" data-height=\"300\" data-default-tab=\"html,result\" data-slug-hash=\"QwjQojW\" data-pen-title=\"Untitled\" data-user=\"ekwwawpb-the-styleful\" style=\"height: 300px; box-sizing: border-box; display: flex; align-items: center; justify-content: center; border: 2px solid; margin: 1em 0; padding: 1em;\">\n  <span>See the Pen <a href=\"https:\/\/codepen.io\/ekwwawpb-the-styleful\/pen\/QwjQojW\"><br \/>\n  Untitled<\/a> by \u5c0f\u7027\u8ce2 (<a href=\"https:\/\/codepen.io\/ekwwawpb-the-styleful\">@ekwwawpb-the-styleful<\/a>)<br \/>\n  on <a href=\"https:\/\/codepen.io\">CodePen<\/a>.<\/span>\n<\/p>\n<p><script async src=\"https:\/\/public.codepenassets.com\/embed\/index.js\"><\/script><br \/>\n\u3055\u3089\u306b\u81e8\u5834\u611f\u3092\u51fa\u3057\u305f\u3044\u5834\u5408\u306f\u300c\u6d41\u308c\u661f\u300d\u3092\u8ffd\u52a0\u3059\u308b\u306e\u304c\u304a\u3059\u3059\u3081\u3067\u3059\u3002<\/p>\n<h3 class=\"sc_heading bborder b blue\"><span class=\"sc_title\" >CSS<\/span><\/h3>\n<pre class=\"line-numbers\" ><code class=\"language-css\">.shooting {\r\n  position: absolute;\r\n  width: 140px;\r\n  height: 2px;\r\n  background: linear-gradient(90deg, rgba(255,255,255,0.9), rgba(255,255,255,0));\r\n  animation: shoot 1.8s ease-in forwards;\r\n}\r\n\r\n@keyframes shoot {\r\n  0%   { transform: translateX(0); opacity: 0; }\r\n  10%  { opacity: 1; }\r\n  100% { transform: translateX(120vw); opacity: 0; }\r\n}\r\n<\/code><\/pre>\n<h3 class=\"sc_heading bborder b blue\"><span class=\"sc_title\" >JavaScript<\/span><\/h3>\n<pre class=\"line-numbers\" ><code class=\"language-js\">function spawnShootingStar() {\r\n  const s = document.createElement(&#039;div&#039;);\r\n  s.className = &#039;shooting&#039;;\r\n  s.style.top = `${rand(5, 45)}%`;\r\n  document.querySelector(&#039;.sky&#039;).appendChild(s);\r\n  setTimeout(() =&gt; s.remove(), 2000);\r\n}\r\n\r\nsetInterval(() =&gt; {\r\n  if (Math.random() &lt; 0.3) spawnShootingStar();\r\n}, 5000);\r\n<\/code><\/pre>\n<p>5\u301c10\u79d2\u306b1\u5ea6\u304f\u3089\u3044\u306e\u983b\u5ea6\u3067\u30e9\u30f3\u30c0\u30e0\u306b\u6d41\u308c\u308b\u3088\u3046\u306b\u3059\u308b\u3068\u81ea\u7136\u3067\u3059!<\/p>\n<h2 class=\"sc_heading solid blue\"><span class=\"sc_title\" >\u30a2\u30af\u30bb\u30b7\u30d3\u30ea\u30c6\u30a3\u306e\u5de5\u592b<\/span><\/h2>\n<p>\u30a2\u30cb\u30e1\u30fc\u30b7\u30e7\u30f3\u3092\u591a\u7528\u3059\u308b\u5834\u5408\u3001\u52d5\u304d\u3092\u6e1b\u3089\u3059\u8a2d\u5b9a\uff08<span class=\"fontbackground\" style=\"background:;\">prefers-reduced-motion<\/span>\uff09\u3092\u8003\u616e\u3059\u308b\u306e\u3082\u5927\u4e8b\u3067\u3059\u3002<\/p>\n<pre class=\"line-numbers\" ><code class=\"language-css\">@media (prefers-reduced-motion: reduce) {\r\n  .star { animation: none; opacity: .8; }\r\n  .shooting { display: none; }\r\n}<\/code><\/pre>\n<h2 class=\"sc_heading solid blue\">\n\t\t<span class=\"sc_title\" >\u307e\u3068\u3081<\/span><br \/>\n\t<\/h2>\n<p>\u4eca\u56de\u3054\u7d39\u4ecb\u3057\u305f\u624b\u6cd5\u3092\u4f7f\u3046\u3068\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u7279\u5fb4\u3092\u6301\u3063\u305f\u80cc\u666f\u30a2\u30cb\u30e1\u30fc\u30b7\u30e7\u30f3\u3092\u5b9f\u88c5\u3067\u304d\u307e\u3059\u3002<\/p>\n<div class=\"sc_designlist ul fa_check blue\">\n<ul>\n<li>\u80cc\u666f\u306b\u81ea\u7136\u306a\u661f\u7a7a\u3092\u8868\u73fe\u3067\u304d\u308b<\/li>\n<li>\u661f\u306e\u6570\u30fb\u30b5\u30a4\u30ba\u30fb\u70b9\u6ec5\u901f\u5ea6\u3092\u81ea\u7531\u306b\u8abf\u6574\u53ef\u80fd<\/li>\n<li>\u6d41\u308c\u661f\u306a\u3069\u6f14\u51fa\u3092\u8ffd\u52a0\u3059\u308b\u3068\u3055\u3089\u306b\u30ea\u30c3\u30c1\u306b<\/li>\n<li>CSS\u3068\u308f\u305a\u304b\u306aJavaScript\u3067\u8efd\u91cf\u306b\u5b9f\u73fe<\/li>\n<\/ul>\n<\/div>\n<p>Web\u30b5\u30a4\u30c8\u306e\u30c8\u30c3\u30d7\u30da\u30fc\u30b8\u3084\u30a4\u30d9\u30f3\u30c8\u544a\u77e5\u30b5\u30a4\u30c8\u306a\u3069\u3067\u6d3b\u7528\u3059\u308c\u3070\u3001\u96f0\u56f2\u6c17\u3092\u5927\u304d\u304f\u5f15\u304d\u7acb\u3066\u3089\u308c\u307e\u3059\u3002<\/p>\n<p>&nbsp;<\/p>\n<p><figure id=\"attachment_475\" aria-describedby=\"caption-attachment-475\" style=\"width: 1500px\" class=\"wp-caption alignnone\"><a href=\"https:\/\/satokotadesign.com\/\" target=\"_blank\" rel=\"noopener\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/satokotadesign.com\/blog\/wp-content\/uploads\/2022\/10\/bnr.jpg\" alt=\"\u9759\u5ca1\u770c\u6d5c\u677e\u5e02\u3067\u30db\u30fc\u30e0\u30da\u30fc\u30b8\u5236\u4f5c\u306a\u3089satokotadesign\" width=\"1500\" height=\"500\" class=\"size-full wp-image-475\" srcset=\"https:\/\/satokotadesign.com\/blog\/wp-content\/uploads\/2022\/10\/bnr.jpg 1500w, https:\/\/satokotadesign.com\/blog\/wp-content\/uploads\/2022\/10\/bnr-500x167.jpg 500w, https:\/\/satokotadesign.com\/blog\/wp-content\/uploads\/2022\/10\/bnr-1024x341.jpg 1024w, https:\/\/satokotadesign.com\/blog\/wp-content\/uploads\/2022\/10\/bnr-768x256.jpg 768w\" sizes=\"auto, (max-width: 1500px) 100vw, 1500px\" \/><\/a><figcaption id=\"caption-attachment-475\" class=\"wp-caption-text\"><a href=\"https:\/\/satokotadesign.com\/contact\/\" target=\"_blank\" rel=\"noopener\">\u9759\u5ca1\u770c\u6d5c\u677e\u5e02\u3067\u30db\u30fc\u30e0\u30da\u30fc\u30b8\u5236\u4f5c\u306a\u3089satokotadesign<\/a><\/figcaption><\/figure><\/p>\n\n","protected":false},"excerpt":{"rendered":"<p>\u3053\u3093\u306b\u3061\u306f\uff01\u9759\u5ca1\u770c\u6d5c\u677e\u5e02\u3067WEB\u30c7\u30b6\u30a4\u30ca\u30fc\u3092\u3057\u3066\u3044\u307e\u3059\u5c0f\u7027\u3067\u3059\u3002 Web\u30b5\u30a4\u30c8\u306e\u80cc\u666f\u6f14\u51fa\u3068\u3057\u3066\u4eba\u6c17\u306e\u9ad8\u3044\u300c\u591c\u7a7a\u306e\u661f\u30a2\u30cb\u30e1\u30fc\u30b7\u30e7\u30f3\u300d\u3002 \u9759\u6b62\u3057\u305f\u80cc\u666f\u753b\u50cf\u3088\u308a\u3082\u3001\u661f\u304c\u30e9\u30f3\u30c0\u30e0\u306b\u70b9\u6ec5\u3057\u3066\u3044\u308b\u3060\u3051\u3067\u30da\u30fc\u30b8\u5168\u4f53\u304c\u30b0\u30c3\u3068\u83ef\u3084\u304b\u306b\u306a\u308a\u307e\u3059\u3002 \u4eca\u56de\u306f CS\u2026<\/p>\n","protected":false},"author":1,"featured_media":2741,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[7],"tags":[8],"class_list":["post-2733","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-web","tag-javascript"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/satokotadesign.com\/blog\/wp-json\/wp\/v2\/posts\/2733","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/satokotadesign.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/satokotadesign.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/satokotadesign.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/satokotadesign.com\/blog\/wp-json\/wp\/v2\/comments?post=2733"}],"version-history":[{"count":8,"href":"https:\/\/satokotadesign.com\/blog\/wp-json\/wp\/v2\/posts\/2733\/revisions"}],"predecessor-version":[{"id":2742,"href":"https:\/\/satokotadesign.com\/blog\/wp-json\/wp\/v2\/posts\/2733\/revisions\/2742"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/satokotadesign.com\/blog\/wp-json\/wp\/v2\/media\/2741"}],"wp:attachment":[{"href":"https:\/\/satokotadesign.com\/blog\/wp-json\/wp\/v2\/media?parent=2733"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/satokotadesign.com\/blog\/wp-json\/wp\/v2\/categories?post=2733"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/satokotadesign.com\/blog\/wp-json\/wp\/v2\/tags?post=2733"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}