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fill="#CF4A27"/><path d="M35.748 47.853c-.587-.226-1.072-.655-1.367-1.21-.022-.634-.144-1.262-.362-1.86h-.567c-.31.073-.636.043-.93-.082-.35-.253-.61-.616-.734-1.03-.082-.17.006-.374.186-.43.172-.083.38 0 .447.177.056.278.215.524.445.69h.586c.37-.086.757-.023 1.08.175.413.585.634 1.284.632 2v.353c.185.177.4.32.632.428.22-.18.42-.382.595-.605-.004-.29.024-.58.083-.865.026-.48.22-.94.55-1.292.506-.235 1.07-.325 1.626-.26.077-.108.14-.227.185-.353-.038-.148.042-.3.186-.353.145-.11.352-.07.447.083.084.084.27.428-.446 1.21-.083.083-.185.176-.27.083-.422-.033-.848-.004-1.264.084-.215.502-.323 1.043-.316 1.59v.176c-.326.57-.824 1.023-1.422 1.293zm-7.198-14.04c-.788-.226-1.61-.314-2.427-.26-1.264 0-2.436.082-2.52.082h-.38v.354s.715 3.55 3.96 3.895c.693.006 1.385-.025 2.074-.093.27-.084 1.71-.428 1.71-.428-.025-1.56-.975-2.956-2.417-3.552zm.53 3.207c-.558.142-1.135.2-1.71.177-1.14-.075-2.16-.728-2.707-1.73-.247-.37-.432-.78-.548-1.21.455 0 1.18-.092 2.073-.175h.596c-.084.688-.242 2.464.483 2.334.725-.13.837-1.46.93-2.13h.112c.937.492 1.647 1.33 1.98 2.334-.388.176-.793.31-1.21.4zm18.365-2.864c-1.104-.145-2.215-.232-3.33-.26-.546-.01-1.093.05-1.626.176-1.166.483-2.08 1.425-2.53 2.604l-.158.79 1.795.623c.558.153 1.132.24 1.71.26h.28c3.245-.177 4.137-3.72 4.137-3.72l.084-.353zm-1.264 1.86c-.54 1.394-2.882 1.646-2.966 1.646-.517-.02-1.03-.11-1.525-.26-.186-.085-.633-.26-1.08-.43.374-.966 1.117-1.746 2.065-2.165 0 .68.158 1.953.81 2.083.65.13.613-1.535.566-2.26.934.005 1.865.064 2.79.177-.11.316-.473.65-.66 1.17z" fill="#151841"/><path d="M19.26 39.27c.535 1.362 1.56 2.473 2.874 3.115.534.312 1.204-.07 1.207-.69.002-.285-.15-.55-.397-.695-.918-.46-1.65-1.222-2.073-2.158-.344-.957-1.972-.52-1.61.428zm29.45 3.125c1.083-.59 2.01-1.428 2.706-2.446.3-.556-.112-1.228-.743-1.21-.293.007-.56.17-.698.428-.568.776-1.306 1.412-2.158 1.86-.394.23-.517.742-.27 1.125.263.376.773.482 1.163.242z" fill="#EFA75B" stroke-width="13"/><path d="M16.025 32.436c1.525-1.386 2.427-4.408 2.79-6.835-.084.354 2.613.43 4.138-1.208 1.078-1.125.446-2-.186-3.375-1.71-3.552-4.585-6.323-7.384-8.918-.716-.69-1.44-2.428-2.706-2-.995.353-.93 3.2-.716 4.073 1.09 7.448 4.065 18.263 4.065 18.263zm37.372-.78c-1.704-1.826-2.822-4.12-3.208-6.585 0 .354-2.614.354-4.056-1.29-.995-1.127-.362-1.86.363-3.117 1.86-3.198 4.863-5.718 7.746-8.136.81-.604 1.627-1.47 2.79-.93.994.428.715 2.334.548 3.115-1.083 5.72-2.48 11.376-4.183 16.943z" fill="#FFF"/><path d="M53.564 20.422c-1.98.51-4.138 1.636-5.105 3.487-.43-2.196 1.645-4.65 3.393-5.832.333-.21.312-.703-.037-.886-.162-.085-.357-.076-.512.022-2.157 1.562-4.417 4.5-3.784 7.188.076.262.354.41.614.325l-.075.28c-.085.603.93.864.994.26.446-2.158 2.706-3.376 4.77-3.897.372-.076.522-.526.27-.81-.133-.15-.342-.204-.53-.138zM17.457 18.06c-.55-.354-.995.428-.55.865 1.433 1.004 3.182 3.05 3.395 4.956-.93-1.86-3.05-2.975-5.105-3.486-.386-.005-.633.41-.445.747.042.076.103.14.176.184 2.073.52 4.324 1.73 4.77 3.896.106.328.5.46.78.26.273.192.653.06.745-.26.735-2.66-1.6-5.728-3.766-7.16z" fill="#F1662A"/></svg></span><p class="course-loading-overlay__message"><b class="course-loading-overlay__message-title">Loading…</b><br><span class="course-loading-overlay__message-text">Everything will be ready in few seconds</span></p></div></div><div class="course-layout__sidebar course-theory"><div class="course-theory__inner course-theory__inner--left-stub"><button class="course-theory__close icon-close icon-close--light" type="button">Close</button><ul class="course-tabs course-tabs--non-interactive course-layout__theory-heading js--theory-tabs"><li class="course-tabs__item course-tabs__item--external course-tab course-tab--centered"><span class="course-tab__icon"><svg aria-hidden="true"><use xlink:href="/img/sprites/courses.svg#icon-theory"></use></svg></span><span class="course-tab__title">Theory</span></li><li class="course-tabs__item course-tabs__item--internal course-tab course-tab--centered course-tab--active js--theory-tab__theory"><span class="course-tab__icon"><svg aria-hidden="true"><use xlink:href="/img/sprites/courses.svg#icon-theory"></use></svg></span><span class="course-tab__title">Theory</span></li><li class="course-tabs__item course-tabs__item--internal course-tab course-tab--centered js--theory-tab__comments"><span class="course-tab__icon"><svg aria-hidden="true" style="width: 16px; height: 16px; fill: #2e2c9c;"><use xlink:href="/img/sprites/up.svg#comment"></use></svg></span><span class="course-tab__title">Comments</span></li></ul><section class="course-theory__content"><div class="js--theory-pane__theory course-theory__content-inner"><h1 class="course-theory__content-heading">Introduction to the event handler</h1><div class="course-theory__content-text"><p>We switched the theme using JavaScript and improved the code by adding a variable. But we were only able to switch the theme on the page once, and we need to make it so that the themes alternate with each other every time we click on the “Change Theme” button.</p><p>JavaScript can monitor everything that happens on the page, and we can tell it what to do if the user clicks a button, for example. First, we find the button itself and save it to a variable:</p><pre><code>let button = document.querySelector('button');</code></pre><p>After the button is found, we tell JavaScript what to do when this button is clicked. This could be, for example, outputting a message to the console:</p><pre><code>button.onclick = function() {
  console.log('Click!');
};</code></pre><p>Instructions that are executed after the button is clicked can be found inside the curly braces.</p><p>From the point of view of the browser, a button click qualifies as an <i>event</i>. The <code>onclick</code> property means “when clicked” and tells JavaScript which event we want to track. And the part of the instruction that is run after <code>onclick</code> is called an event handler. We will analyze this in detail in one of the following chapters.</p><p>Although this event is called “click”, it really means any sort of activation — whether by a mouse click, other pointing devices, or with the keyboard.</p><p>The “Change Theme” button, which should change themes when it is clicked, has the <code class="nowrap">theme-button</code> class. Let’s find it and see how the event handler works. Let’s use the console again to test it: tell JavaScript to output the message each time the button is clicked.</p><div class="info info--frame-heading info--frame-heading--bytheway info--green"><p>JavaScript has another method for creating an event handler. We will discuss it in the following chapters, but if you’re curious, you can read about it <a href="https://developer.mozilla.org/en-US/docs/Web/API/EventTarget/addEventListener" target="_blank" rel="nofollow noopener">in the JavaScript documentation</a>.</p></div></div></div><div class="js--theory-pane__comments hidden course-theory__content-inner"><div class="course-theory__content-text"><h2 class="course-theory__content-heading">Comments</h2><div id="disqus_thread"></div><script>
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                    </script><noscript>Please enable JavaScript to view the <a href="https://disqus.com/?ref_noscript">comments powered by Disqus.</a></noscript></div></div></section><div class="course-theory__controls"><button class="button button--close" type="button">To the task</button></div></div></div><div class="course-layout__column course-layout__column--left"><ul class="js--course-tabs course-tabs course-layout__course-tabs"><li class="js--editor-tab course-tabs__item course-tab course-tabs__item--limited course-tabs__item--limited-large course-tab--active" data-editor="html"><span class="course-tab__title course-tab__title--indent"><span class="course-tab__title-part course-tab__title-part--active">index.html</span></span><button class="js--editor-split course-tab__button course-tab__button--split" type="button"><svg aria-hidden="true"><use xlink:href="/img/sprites/courses.svg#icon-split"></use></svg><span class="tooltip tooltip--light tooltip--to-top tooltip--with-wrap tooltip--short course-tab__tooltip"><span class="tooltip__wrap">Split mode</span></span></button></li><li class="js--editor-tab course-tabs__item course-tab course-tabs__item--limited course-tabs__item--limited-large" data-editor="css"><span class="course-tab__title course-tab__title--indent"><span class="course-tab__title-part course-tab__title-part--active">style.css</span></span><button class="js--editor-split course-tab__button course-tab__button--split" type="button"><svg aria-hidden="true"><use xlink:href="/img/sprites/courses.svg#icon-split"></use></svg><span class="tooltip tooltip--light tooltip--to-top tooltip--with-wrap tooltip--short course-tab__tooltip"><span class="tooltip__wrap">Split mode</span></span></button></li><li class="js--editor-tab course-tabs__item course-tab course-tabs__item--limited course-tabs__item--limited-large" data-editor="js"><span class="course-tab__title course-tab__title--indent"><span class="course-tab__title-part course-tab__title-part--active">script.js</span></span><button class="js--editor-split course-tab__button course-tab__button--split" type="button"><svg aria-hidden="true"><use xlink:href="/img/sprites/courses.svg#icon-split"></use></svg><span class="tooltip tooltip--light tooltip--to-top tooltip--with-wrap tooltip--short course-tab__tooltip"><span class="tooltip__wrap">Split mode</span></span></button></li></ul><div class="course-layout__editors"><div class="js--editor course-editor course-layout__editor" id="" data-tab="html" data-split=""><span class="course-editor__label"><span class="course-editor__label-item">HTML</span><button class="course-editor__label-item course-editor__label-item--interactive hidden js--editor__unsplit-button course-editor__label-item--simple" title="No split" type="button"><svg width="7" height="10" viewBox="0 0 7 10" xmlns="http://www.w3.org/2000/svg"><g stroke="currentColor" fill="none" fill-rule="evenodd"><path stroke-linecap="round" d="M.6 3.503L3.443.518l2.842 2.985"></path><path d="M3.5 1.5v7.16" stroke-linecap="square"></path></g></svg></button></span><div class="course-editor__item" id="html-editor">&lt;!DOCTYPE html&gt;
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          &lt;h2 class=&quot;news-list-heading&quot;&gt;Or continue reading more news stories.&lt;/h2&gt;
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</div></div><div class="js--editor course-editor course-layout__editor course-editor--hidden" id="" data-tab="css" data-split=""><span class="course-editor__label"><span class="course-editor__label-item">CSS</span><button class="course-editor__label-item course-editor__label-item--interactive hidden js--editor__unsplit-button course-editor__label-item--simple" title="No split" type="button"><svg width="7" height="10" viewBox="0 0 7 10" xmlns="http://www.w3.org/2000/svg"><g stroke="currentColor" fill="none" fill-rule="evenodd"><path stroke-linecap="round" d="M.6 3.503L3.443.518l2.842 2.985"></path><path d="M3.5 1.5v7.16" stroke-linecap="square"></path></g></svg></button></span><div class="course-editor__item" id="css-editor">/* Light theme */
.light-theme {
  color: #333333;
  background-color: #eae9f2;
}

.light-theme .page-header {
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  box-shadow: 0 2px 2px rgba(0, 0, 0, 0.2);
}

.light-theme .header-link {
  color: #6653d9;
}

.light-theme .header-link::before {
  background: url(&quot;img/arrow-back-light.svg&quot;) no-repeat 0 0;
}

.light-theme .theme-button {
  color: #6653d9;
  border: 1px solid #6653d9;
}

.light-theme .theme-button::before {
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}

.light-theme .theme-button:focus,
.light-theme .theme-button:hover {
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}

.light-theme .theme-button:focus::before,
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}

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}

.light-theme .menu-open:focus,
.light-theme .menu-open:hover {
  background-color: #6653d9;
  background-image: url(&quot;img/menu-open-dark.svg&quot;);
}

.light-theme .menu-close {
  background-color: #6653d9;
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.light-theme .menu-close:focus,
.light-theme .menu-close:hover {
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  color: #ffffff;
}

.light-theme .main-menu a:focus,
.light-theme .main-menu a:hover {
  background-color: #473c8d;
}

.light-theme .news-view button {
  border: 1px solid #6653d9;
  color: #6653d9;
}

.light-theme .news-view button:focus,
.light-theme .news-view button:hover,
.light-theme .news-view button:active,
.light-theme .news-view .view-checked {
  background-color: #6653d9;
  color: #ffffff;
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.light-theme .news-view .row-view:focus::before,
.light-theme .news-view .row-view:hover::before,
.light-theme .news-view .row-view:active::before {
  background-image: url(&quot;img/rows-light-checked.svg&quot;);
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.light-theme .news-view .tile-view:focus::before,
.light-theme .news-view .tile-view:hover::before,
.light-theme .news-view .tile-view:active::before {
  background-image: url(&quot;img/tiles-light-checked.svg&quot;);
}

.light-theme .row-view::before {
  background-image: url(&quot;img/rows-light.svg&quot;);
}

.light-theme .tile-view::before {
  background-image: url(&quot;img/tiles-light.svg&quot;);
}

.light-theme .row-view::before {
  background-image: url(&quot;img/rows-light.svg&quot;);
}

.light-theme .row-view.view-checked::before {
  background-image: url(&quot;img/rows-light-checked.svg&quot;);
}

.light-theme .tile-view.view-checked::before {
  background-image: url(&quot;img/tiles-light-checked.svg&quot;);
}

.light-theme .new-block {
  background-color: #ffffff;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.2);
}

.light-theme .new-block time {
  color: #aaaaaa;
}

.light-theme .cookies-agreement {
  background-color: #fdeacd;
  box-shadow: 0 -1px 4px rgba(0, 0, 0, 0.2);
}

.light-theme .button {
  background-color: #6653d9;
  color: #ffffff;
}

.light-theme .button:focus,
.light-theme .button:hover {
  background-color: #473c8d;
}

.light-theme .page-footer {
  background-color: #6653d9;
  color: #ffffff;
}

.light-theme .subscription {
  background-color: #ffffff;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.2);
}

.light-theme .subscription-message {
  background-color: #6653d9;
  color: #eae9f2;
}

.light-theme .subscription-message::before {
  background-image: url(&quot;img/icon-ok-light.svg&quot;);
}

.light-theme .subscription-label {
  color: #6653d9;
}

.light-theme .subscription-email {
  border-bottom: 1px solid #6653d9;
  color: #333333;
}

/* Dark theme */
.dark-theme {
  color: #f2f2f2;
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}

.dark-theme .page-header {
  background-color: #373540;
  box-shadow: 0 2px 2px rgba(0, 0, 0, 0.6);
}

.dark-theme .header-link {
  color: #9484f2;
}

.dark-theme .header-link::before {
  background: url(&quot;img/arrow-back-dark.svg&quot;) no-repeat 0 0;
}

.dark-theme .theme-button {
  color: #9484f2;
  border: 1px solid #9484f2;
}

.dark-theme .theme-button::before {
  background-image: url(&quot;img/sun-normal.svg&quot;);
}

.dark-theme .theme-button:focus,
.dark-theme .theme-button:hover {
  color: #17161a;
  background-color: #9484f2;
}

.dark-theme .theme-button:focus::before,
.dark-theme .theme-button:hover::before {
  background-image: url(&quot;img/sun-hover.svg&quot;);
}

.dark-theme .menu-open {
  background-color: #373540;
  background-image: url(&quot;img/menu-open-dark.svg&quot;);
}

.dark-theme .menu-open:focus,
.dark-theme .menu-open:hover {
  background-color: #473c8d;
  background-image: url(&quot;img/menu-open-dark.svg&quot;);
}

.dark-theme .menu-close {
  background-color: #473c8d;
}

.dark-theme .menu-close:focus,
.dark-theme .menu-close:hover {
  background-color: #6653d9;
}

.dark-theme .main-menu {
  background-color: #473c8d;
  color: #f2f2f2;
}

.dark-theme .main-menu a:focus,
.dark-theme .main-menu a:hover {
  background-color: #6653d9;
}

.dark-theme .news-view button {
  border: 1px solid #9484f2;
  color: #9484f2;
}

.dark-theme .news-view button:focus,
.dark-theme .news-view button:hover,
.dark-theme .news-view button:active,
.dark-theme .news-view .view-checked {
  background-color: #9484f2;
  color: #17161a;
}

.dark-theme .news-view .row-view:focus::before,
.dark-theme .news-view .row-view:hover::before,
.dark-theme .news-view .row-view:active::before {
  background-image: url(&quot;img/rows-dark-checked.svg&quot;);
}

.dark-theme .news-view .tile-view:focus::before,
.dark-theme .news-view .tile-view:hover::before,
.dark-theme .news-view .tile-view:active::before {
  background-image: url(&quot;img/tiles-dark-checked.svg&quot;);
}

.dark-theme .row-view::before {
  background-image: url(&quot;img/rows-dark.svg&quot;);
}

.dark-theme .tile-view::before {
  background-image: url(&quot;img/tiles-dark.svg&quot;);
}

.dark-theme .row-view.view-checked::before {
  background-image: url(&quot;img/rows-dark-checked.svg&quot;);
}

.dark-theme .tile-view.view-checked::before {
  background-image: url(&quot;img/tiles-dark-checked.svg&quot;);
}

.dark-theme .new-block {
  background-color: #2a2930;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.6);
}

.dark-theme .new-block time {
  color: #888888;
}

.dark-theme .cookies-agreement {
  background-color: #473c8d;
  box-shadow: 0 -1px 4px rgba(0, 0, 0, 0.6);
}

.dark-theme .button {
  background-color: #9484f2;
  color: #17161a;
}

.dark-theme .button:focus,
.dark-theme .button:hover {
  background-color: #b6aaff;
}

.dark-theme .page-footer {
  background-color: #0a0910;
  color: #f2f2f2;
}

.dark-theme .subscription {
  background-color: #2a2930;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.6);
}

.dark-theme .subscription-message {
  background-color: #9484f2;
  color: #17161a;
}

.dark-theme .subscription-message::before {
  background-image: url(&quot;img/icon-ok-dark.svg&quot;);
}

.dark-theme .subscription-label {
  color: #9484f2;
}

.dark-theme .subscription-email {
  border-bottom: 1px solid #9484f2;
  color: #f2f2f2;
}
</div></div><div class="js--editor course-editor course-layout__editor course-editor--hidden" id="" data-tab="js" data-split=""><span class="course-editor__label"><span class="course-editor__label-item">JavaScript</span><button class="course-editor__label-item course-editor__label-item--interactive hidden js--editor__unsplit-button course-editor__label-item--simple" title="No split" type="button"><svg width="7" height="10" viewBox="0 0 7 10" xmlns="http://www.w3.org/2000/svg"><g stroke="currentColor" fill="none" fill-rule="evenodd"><path stroke-linecap="round" d="M.6 3.503L3.443.518l2.842 2.985"></path><path d="M3.5 1.5v7.16" stroke-linecap="square"></path></g></svg></button></span><div class="course-editor__item" id="js-editor">let page = document.querySelector(&#039;.page&#039;);
page.classList.remove(&#039;light-theme&#039;);
page.classList.add(&#039;dark-theme&#039;);

</div></div></div><div class="course-editor-controls"><button class="course-editor-controls__item course-editor-controls__item--answer" type="button">Show the answer</button></div><div class="js--feedback course-unhappy"><button class="js--feedback-btn course-unhappy__button" type="button"><span class="sr-only">Complain</span><svg aria-hidden="true"><use xlink:href="/img/sprites/courses.svg#unhappy"></use></svg></button><div class="js--feedback-modal course-unhappy__modal course-unhappy__modal--step-one"><form method="POST" action="/courses/intro-to-web-development/javascript/event-handler/signal" class="course-unhappy__form form"><input type="hidden" name="csrf_name" value="csrf69aea52373689"><input type="hidden" name="csrf_value" value="29379e4590e8a3480f2af7714b94736f"><p class="course-unhappy__text">What didn’t you like in this task?</p><div class="course-unhappy__slide"><div class="course-unhappy__wrap"><div class="course-unhappy__list"><label class="checkbox checkbox--small"><input class="checkbox__input" name="problems" value="1" type="checkbox"><span class="checkbox__text">The code check doesn’t work</span></label><label class="checkbox checkbox--small"><input class="checkbox__input" name="problems" value="2" type="checkbox"><span class="checkbox__text">The task is too difficult</span></label><label class="checkbox checkbox--small"><input class="checkbox__input" name="problems" value="3" type="checkbox"><span class="checkbox__text">The theory is hard to understand</span></label><label class="checkbox checkbox--small"><input class="js--feedback-other-checkbox checkbox__input" name="problems" value="0" type="checkbox"><span class="checkbox__text">Other (will write below)</span></label></div><div class="course-unhappy__message"><label class="sr-only" for="id-message">Другое (сейчас напишу)</label><textarea class="field field--area" id="id-message" name="message" placeholder="For example, a typo in the word «heading»"></textarea></div></div></div><button class="course-unhappy__control course-unhappy__control--prev" type="button"><span class="sr-only">Prev</span><svg aria-hidden="true"><use xlink:href="/img/sprites/landings.svg#arrow"></use></svg></button><button class="course-unhappy__control course-unhappy__control--next" type="button" disabled><span class="sr-only">Next</span><svg aria-hidden="true"><use xlink:href="/img/sprites/landings.svg#arrow"></use></svg></button><button class="js--submit-btn button" disabled>Submit</button></form><p class="course-unhappy__result hidden">Thanks! We’ll fix everything at once!</p></div></div></div><div class="course-layout__column course-layout__column--right"><span class="course-separator-control"><svg aria-hidden="true"><use xlink:href="/img/sprites/courses.svg#icon-arrows-separator"></use></svg></span><div class="course-browser course-layout__browser"><div class="course-browser__menu"><span class="course-browser__menu-item course-browser__address"><span class="course-browser__menu-item-inner"><span class="course-browser__address-text"></span></span></span><button class="js--autorun course-browser__menu-item course-browser__menu-button course-browser__menu-button--text-with-icon course-browser__menu-button--autorun course-browser__menu-button--autorun-on" title="Autorun" type="button"><span class="course-browser__menu-item-inner"><svg aria-hidden="true"><use xlink:href="/img/sprites/courses.svg#icon-autorun"></use></svg>
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    </span></button><button class="course-browser__menu-item course-browser__menu-button course-browser__menu-button--expand" type="button"><svg xmlns="http://www.w3.org/2000/svg" width="11" height="11" viewBox="0 0 11 11"><path d="M1.375 5.125v4.5h4.5m3.75-3.75v-4.5h-4.5" fill="none" fill-rule="evenodd" stroke="currentColor"></path></svg></button></div><div class="course-browser__content"><div class="course-browser__zoomer"><iframe class="course-browser__zoomer-element js--preview-document"></iframe><p class="course-browser__focus-message">
          Click inside the mini browser to put the focus in this window.
        </p></div><div class="course-browser__menu course-browser__menu--vertical"><button class="course-browser__menu-item course-browser__menu-button course-browser__menu-button--increase" type="button" disabled title="Larger"><span class="course-browser__menu-item-inner">Larger</span></button><span class="course-browser__menu-item course-browser__zoom"><span class="course-browser__menu-item-inner">100%</span></span><button class="course-browser__menu-item course-browser__menu-button course-browser__menu-button--decrease" type="button" title="Smaller"><span class="course-browser__menu-item-inner">Smaller</span></button></div></div><div class="console console--modal console--modal-collapsed js--console"><div class="console__heading"><span class="console__heading-title">Console<span class="console__counter hidden js--console__counter"></span></span><button class="console__heading-button js--console__toggle" type="button" title="Switch console"><svg aria-hidden="true"><use xlink:href="/img/sprites/courses.svg#icon-collapse"></use></svg></button></div><div class="console__content js--console__content"></div></div><div class="course-goals js--goals"><div class="course-goals__heading"><span class="course-goals__heading-title"><span class="course-goals__count-label">Goals</span><span class="course-goals__count">completed</span></span><div class="js--annotations course-task-stats course-task-stats--disabled  course-task-stats--centered "><span class="course-task-stats__indicator"><svg width="12" height="12" viewBox="0 0 16 16" fill="none" xmlns="http://www.w3.org/2000/svg"><path fill-rule="evenodd" clip-rule="evenodd" d="M15 8C15 11.866 11.866 15 8 15C4.13403 15 1 11.866 1 8C1 4.13403 4.13403 1 8 1C11.866 1 15 4.13403 15 8ZM16 8C16 12.4183 12.4183 16 8 16C3.58173 16 0 12.4183 0 8C0 3.58173 3.58173 0 8 0C12.4183 0 16 3.58173 16 8ZM6.7287 3.88849C6.6958 3.59229 6.92761 3.33325 7.22565 3.33325H8.77502C9.07306 3.33325 9.30487 3.59229 9.27197 3.88849L8.71643 8.88849C8.68829 9.14166 8.47424 9.33325 8.21948 9.33325H7.78119C7.52643 9.33325 7.31238 9.14166 7.28424 8.88849L6.7287 3.88849ZM9.33368 12.0001C9.33368 12.7365 8.73669 13.3334 8.00031 13.3334C7.26392 13.3334 6.66699 12.7365 6.66699 12.0001C6.66699 11.2637 7.26392 10.6667 8.00031 10.6667C8.73669 10.6667 9.33368 11.2637 9.33368 12.0001Z" fill="currentColor"></path></svg><span class="js--annotations-counter course-task-stats__counter">0</span></span><div class="course-task-stats__scroller-wrapper"><div class="course-task-stats__scroller"><ul class="js--annotations-list course-task-stats__list"></ul></div></div></div><button class="course-goals__button course-goals__button--expand js--goals__expand" type="button"><svg aria-hidden="true"><use xlink:href="/img/sprites/courses.svg#icon-collapse"></use></svg></button><a class="course-goals__button course-goals__button--next button button--green button--without-border hidden" href="/courses/intro-to-web-development/javascript/switch-theme" title="Let’s make it so that the theme is switched when the button is clicked"><svg aria-hidden="true"><use xlink:href="/img/sprites/courses.svg#arrow-white--mini"></use></svg></a></div><div class="course-goals__content"><ol class="course-goals__list"><li class="course-goals__list-item">On line 5, declare a variable <code>themeButton</code> and write an element to it with the class <code class="nowrap">theme-button</code><span class="mark">.</span></li><li class="course-goals__list-item">On the next line, add the following event handler: <code class="nowrap">themeButton.onclick = function() {};</code><span class="mark">.</span></li><li class="course-goals__list-item">Inside the curly braces of the handler, add the following to be output to the console: <code>console.log('Button pressed!');</code><span class="mark">.</span></li><li class="course-goals__list-item">Double click on the “Change Theme” button in the mini-browser</li><li class="course-goals__list-item">Verify that the two new messages appear in the console.</li></ol></div></div></div></div></article></div><div class="course-interface__overlay course-interface__overlay--active"></div></main><script
    src="https://assets.htmlacademy.org/scripts/courses-spa/htmlacademy-task.v43.js"
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