Question

我正试图在动画的网站（仍然是一个项目）上设置搜索栏的动画，但搜索输入只是在动画开始时传送给自己：

我正在使用jQuery来制作动画，因为当我点击它时我想做其他事情，比如隐藏徽标和这样的东西。这是我的代码：

$(".search-field").focus(function () {
    $(this).animate({ "width": "100%" }, "slow" );

    // $(".logo").fadeOut();
});
$(".search-field").focusout(function () {
    $(this).animate({ "width": "130px" }, "slow" );
    // $(".logo").fadeIn();
});

@import url('https://fonts.googleapis.com/css?family=Roboto+Slab');
/*! HTML5 Boilerplate v5.3.0 | MIT License | https://html5boilerplate.com/ */

/*
 * What follows is the result of much research on cross-browser styling.
 * Credit left inline and big thanks to Nicolas Gallagher, Jonathan Neal,
 * Kroc Camen, and the H5BP dev community and team.
 */

/* ==========================================================================
   Base styles: opinionated defaults
   ========================================================================== */

html {
    color: #222;
    font-size: 1em;
    line-height: 1.4;
    z-index: 1;
}

/*
 * Remove text-shadow in selection highlight:
 * https://twitter.com/miketaylr/status/12228805301
 *
 * These selection rule sets have to be separate.
 * Customize the background color to match your design.
 */

::-moz-selection {
    background: #b3d4fc;
    text-shadow: none;
}

::selection {
    background: #b3d4fc;
    text-shadow: none;
}

/*
 * A better looking default horizontal rule
 */

hr {
    display: block;
    height: 1px;
    border: 0;
    border-top: 1px solid #ccc;
    margin: 1em 0;
    padding: 0;
}

/*
 * Remove the gap between audio, canvas, iframes,
 * images, videos and the bottom of their containers:
 * https://github.com/h5bp/html5-boilerplate/issues/440
 */

audio,
canvas,
iframe,
img,
svg,
video {
    vertical-align: middle;
}

/*
 * Remove default fieldset styles.
 */

fieldset {
    border: 0;
    margin: 0;
    padding: 0;
}

/*
 * Allow only vertical resizing of textareas.
 */

textarea {
    resize: vertical;
}

/* ==========================================================================
   Browser Upgrade Prompt
   ========================================================================== */

.browserupgrade {
    margin: 0.2em 0;
    background: #ccc;
    color: #000;
    padding: 0.2em 0;
}

/* ==========================================================================
   Author's custom styles
   ========================================================================== */

















/* ==========================================================================
   Helper classes
   ========================================================================== */

/*
 * Hide visually and from screen readers
 */

.hidden {
    display: none !important;
}

/*
 * Hide only visually, but have it available for screen readers:
 * http://snook.ca/archives/html_and_css/hiding-content-for-accessibility
 */

.visuallyhidden {
    border: 0;
    clip: rect(0 0 0 0);
    height: 1px;
    margin: -1px;
    overflow: hidden;
    padding: 0;
    position: absolute;
    width: 1px;
}

/*
 * Extends the .visuallyhidden class to allow the element
 * to be focusable when navigated to via the keyboard:
 * https://www.drupal.org/node/897638
 */

.visuallyhidden.focusable:active,
.visuallyhidden.focusable:focus {
    clip: auto;
    height: auto;
    margin: 0;
    overflow: visible;
    position: static;
    width: auto;
}

/*
 * Hide visually and from screen readers, but maintain layout
 */

.invisible {
    visibility: hidden;
}

/*
 * Clearfix: contain floats
 *
 * For modern browsers
 * 1. The space content is one way to avoid an Opera bug when the
 *    `contenteditable` attribute is included anywhere else in the document.
 *    Otherwise it causes space to appear at the top and bottom of elements
 *    that receive the `clearfix` class.
 * 2. The use of `table` rather than `block` is only necessary if using
 *    `:before` to contain the top-margins of child elements.
 */

.clearfix:before,
.clearfix:after {
    content: " "; /* 1 */
    display: table; /* 2 */
}

.clearfix:after {
    clear: both;
}

/* ==========================================================================
   EXAMPLE Media Queries for Responsive Design.
   These examples override the primary ('mobile first') styles.
   Modify as content requires.
   ========================================================================== */

@media only screen and (min-width: 35em) {
    /* Style adjustments for viewports that meet the condition */
}

@media print,
       (-webkit-min-device-pixel-ratio: 1.25),
       (min-resolution: 1.25dppx),
       (min-resolution: 120dpi) {
    /* Style adjustments for high resolution devices */
}

/* ==========================================================================
   Print styles.
   Inlined to avoid the additional HTTP request:
   http://www.phpied.com/delay-loading-your-print-css/
   ========================================================================== */

@media print {
    *,
    *:before,
    *:after,
    *:first-letter,
    *:first-line {
        background: transparent !important;
        color: #000 !important; /* Black prints faster:
                                   http://www.sanbeiji.com/archives/953 */
        box-shadow: none !important;
        text-shadow: none !important;
    }

    a,
    a:visited {
        text-decoration: underline;
    }

    a[href]:after {
        content: " (" attr(href) ")";
    }

    abbr[title]:after {
        content: " (" attr(title) ")";
    }

    /*
     * Don't show links that are fragment identifiers,
     * or use the `javascript:` pseudo protocol
     */

    a[href^="#"]:after,
    a[href^="javascript:"]:after {
        content: "";
    }

    pre,
    blockquote {
        border: 1px solid #999;
        page-break-inside: avoid;
    }

    /*
     * Printing Tables:
     * http://css-discuss.incutio.com/wiki/Printing_Tables
     */

    thead {
        display: table-header-group;
    }

    tr,
    img {
        page-break-inside: avoid;
    }

    img {
        max-width: 100% !important;
    }

    p,
    h2,
    h3 {
        orphans: 3;
        widows: 3;
    }

    h2,
    h3 {
        page-break-after: avoid;
    }
}
/* ==========================================================================
   Real CSS
   ========================================================================== */
body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
    font-size: 14px;
    line-height: 1.5;
}
.top {
    position: fixed;
    height: 50px;
    /*padding: 12px;*/
    width: 100vw;
    background-color: #24292e;
    color: rgba(255, 255, 255, 0.75);
    z-index: 10;
}
.container {
    padding-top: 2px;
    width: 980px;
    margin-right: auto;
    margin-left: auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.nav {
    list-style: none;
    padding-left: 0;
    margin-top: 0;
    margin-bottom: 0
}
.nav-item {
    padding: 12px;
    float: left;
    list-style: none;
}
.logo {
    flex: unset;
}
.header-item {
    display: flex;
    flex-direction: row;
}
.nav-item1 {
    width: 300px;
    justify-content: space-around;
}
.nav-item3 {
    width: 300px;
    justify-content: space-between;
}
.search-field {
    width: 130px;
    border: 2px solid #ccc;
    border-radius: 4px;
    font-size: 16px;
    background-color: rgba(255, 255, 255, 0.3);
    background-image: url('https://cdn.rawgit.com/encharm/Font-Awesome-SVG-PNG/b7f74631/black/png/24/search.png');
    background-position: 3px 3px;
    background-repeat: no-repeat;
    padding: 6px 20px 6px 40px;
    transition: width 0.4s ease-in-out;
}

.sign {
    display: flex;
    flex-direction: row;
}
.sign-in {
    margin-left: auto;
    padding: 5px;
    border: 3px solid rgba(255, 255, 255, 0.75);
    border-right-width: 0px;
    border-top-left-radius: 5px;
    border-bottom-left-radius: 5px;
}
.sign-up {
    margin-left: auto;
    padding: 5px;
    border: 3px solid rgba(255, 255, 255, 0.75);
    border-top-right-radius: 5px;
    border-bottom-right-radius: 5px;
}

.div-title {
    width: 50vw;
    position: absolute;
    margin-left: 20vw;
    margin-top: 75px;
    color: grey;
}
.posts {
    width: 50vw;
    position: absolute;
    margin-left: 20vw;
    margin-top: 125px;
}
.post {
    width: 100%;
    height: 25vh;
    border: 1px solid #F2F2F2;
    margin-bottom: 20px;
    /*box-shadow: 0px 0px 5px #888888;*/
}
.post > .profile {
    z-index: 2;
    position: absolute;
    margin-top: 7vh;
    margin-left: 20px;
}
.post > .title {
    font-family: 'Roboto Slab', serif;
    font-size: 1.5em;
    margin-left: 100px;
    margin-top: 15px;
}
.post > .content {
    margin-left: 100px;
    margin-top: 10px;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="top" role="banner">
            <div class="container">
                <div class="nav-item1 header-item">
                    <div class="logo">Logo</div>
                    <div class="search">
                        <input type="text" class="search-field" name="search" placeholder="Search...">
                    </div>
                </div>
                <div class="nav-item2 header-item">
                    <ul class="nav">
                        <li class="nav-item">New</li>
                        <li class="nav-item">Home</li>
                        <li class="nav-item">Explore</li>
                    </ul>
                </div>
                <div class="nav-item3 header-item">
                    <div class="sign">
                        <div class="sign-in">Sign In</div>
                        <div class="sign-up">Sign Up</div>
                    </div>
                </div>

            </div>
        </div>

你能帮我解决一下取消“传送”的方法，或者给我一个让它看起来更平滑的技巧吗？

Answer 1

设置宽度动画的最简单方法是将宽度设置为100％，然后为最大宽度设置动画。

对addClass / removeClass而言，这不是一个好主意，而是直接使用jQuery制作动画

这是我在CSS中更改/添加的内容。然后javascript只会添加.expand

.search-field {
    width:100%;
    max-width:130px;
    border: 2px solid #ccc;
    border-radius: 4px;
    font-size: 16px;
    background-color: rgba(255, 255, 255, 0.3);
    background-image: url('https://cdn.rawgit.com/encharm/Font-Awesome-SVG-PNG/b7f74631/black/png/24/search.png');
    background-position: 3px 3px;
    background-repeat: no-repeat;
    padding: 6px 20px 6px 40px;
    transition: max-width 0.4s ease-in-out;
}

.search-field.expand{
    max-width:500px;
}

看一下这个片段：

＆＃13;

$(".search-field").focus(function () {
    $(this).addClass('expand');
});
$(".search-field").focusout(function () {
    $(this).removeClass('expand');
    // $(".logo").fadeIn();
});

＆＃13;

@import url('https://fonts.googleapis.com/css?family=Roboto+Slab');
/*! HTML5 Boilerplate v5.3.0 | MIT License | https://html5boilerplate.com/ */

/*
 * What follows is the result of much research on cross-browser styling.
 * Credit left inline and big thanks to Nicolas Gallagher, Jonathan Neal,
 * Kroc Camen, and the H5BP dev community and team.
 */

/* ==========================================================================
   Base styles: opinionated defaults
   ========================================================================== */

html {
    color: #222;
    font-size: 1em;
    line-height: 1.4;
    z-index: 1;
}

/*
 * Remove text-shadow in selection highlight:
 * https://twitter.com/miketaylr/status/12228805301
 *
 * These selection rule sets have to be separate.
 * Customize the background color to match your design.
 */

::-moz-selection {
    background: #b3d4fc;
    text-shadow: none;
}

::selection {
    background: #b3d4fc;
    text-shadow: none;
}

/*
 * A better looking default horizontal rule
 */

hr {
    display: block;
    height: 1px;
    border: 0;
    border-top: 1px solid #ccc;
    margin: 1em 0;
    padding: 0;
}

/*
 * Remove the gap between audio, canvas, iframes,
 * images, videos and the bottom of their containers:
 * https://github.com/h5bp/html5-boilerplate/issues/440
 */

audio,
canvas,
iframe,
img,
svg,
video {
    vertical-align: middle;
}

/*
 * Remove default fieldset styles.
 */

fieldset {
    border: 0;
    margin: 0;
    padding: 0;
}

/*
 * Allow only vertical resizing of textareas.
 */

textarea {
    resize: vertical;
}



/* ==========================================================================
   Browser Upgrade Prompt
   ========================================================================== */

.browserupgrade {
    margin: 0.2em 0;
    background: #ccc;
    color: #000;
    padding: 0.2em 0;
}

/* ==========================================================================
   Author's custom styles
   ========================================================================== */

















/* ==========================================================================
   Helper classes
   ========================================================================== */

/*
 * Hide visually and from screen readers
 */

.hidden {
    display: none !important;
}

/*
 * Hide only visually, but have it available for screen readers:
 * http://snook.ca/archives/html_and_css/hiding-content-for-accessibility
 */

.visuallyhidden {
    border: 0;
    clip: rect(0 0 0 0);
    height: 1px;
    margin: -1px;
    overflow: hidden;
    padding: 0;
    position: absolute;
    width: 1px;
}

/*
 * Extends the .visuallyhidden class to allow the element
 * to be focusable when navigated to via the keyboard:
 * https://www.drupal.org/node/897638
 */

.visuallyhidden.focusable:active,
.visuallyhidden.focusable:focus {
    clip: auto;
    height: auto;
    margin: 0;
    overflow: visible;
    position: static;
    width: auto;
}

/*
 * Hide visually and from screen readers, but maintain layout
 */

.invisible {
    visibility: hidden;
}

/*
 * Clearfix: contain floats
 *
 * For modern browsers
 * 1. The space content is one way to avoid an Opera bug when the
 *    `contenteditable` attribute is included anywhere else in the document.
 *    Otherwise it causes space to appear at the top and bottom of elements
 *    that receive the `clearfix` class.
 * 2. The use of `table` rather than `block` is only necessary if using
 *    `:before` to contain the top-margins of child elements.
 */

.clearfix:before,
.clearfix:after {
    content: " "; /* 1 */
    display: table; /* 2 */
}

.clearfix:after {
    clear: both;
}

/* ==========================================================================
   EXAMPLE Media Queries for Responsive Design.
   These examples override the primary ('mobile first') styles.
   Modify as content requires.
   ========================================================================== */

@media only screen and (min-width: 35em) {
    /* Style adjustments for viewports that meet the condition */
}

@media print,
       (-webkit-min-device-pixel-ratio: 1.25),
       (min-resolution: 1.25dppx),
       (min-resolution: 120dpi) {
    /* Style adjustments for high resolution devices */
}

/* ==========================================================================
   Print styles.
   Inlined to avoid the additional HTTP request:
   http://www.phpied.com/delay-loading-your-print-css/
   ========================================================================== */

@media print {
    *,
    *:before,
    *:after,
    *:first-letter,
    *:first-line {
        background: transparent !important;
        color: #000 !important; /* Black prints faster:
                                   http://www.sanbeiji.com/archives/953 */
        box-shadow: none !important;
        text-shadow: none !important;
    }

    a,
    a:visited {
        text-decoration: underline;
    }

    a[href]:after {
        content: " (" attr(href) ")";
    }

    abbr[title]:after {
        content: " (" attr(title) ")";
    }

    /*
     * Don't show links that are fragment identifiers,
     * or use the `javascript:` pseudo protocol
     */

    a[href^="#"]:after,
    a[href^="javascript:"]:after {
        content: "";
    }

    pre,
    blockquote {
        border: 1px solid #999;
        page-break-inside: avoid;
    }

    /*
     * Printing Tables:
     * http://css-discuss.incutio.com/wiki/Printing_Tables
     */

    thead {
        display: table-header-group;
    }

    tr,
    img {
        page-break-inside: avoid;
    }

    img {
        max-width: 100% !important;
    }

    p,
    h2,
    h3 {
        orphans: 3;
        widows: 3;
    }

    h2,
    h3 {
        page-break-after: avoid;
    }
}
/* ==========================================================================
   Real CSS
   ========================================================================== */
body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
    font-size: 14px;
    line-height: 1.5;
}
.top {
    position: fixed;
    height: 50px;
    /*padding: 12px;*/
    width: 100vw;
    background-color: #24292e;
    color: rgba(255, 255, 255, 0.75);
    z-index: 10;
}
.container {
    padding-top: 2px;
    width: 980px;
    margin-right: auto;
    margin-left: auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.nav {
    list-style: none;
    padding-left: 0;
    margin-top: 0;
    margin-bottom: 0
}
.nav-item {
    padding: 12px;
    float: left;
    list-style: none;
}
.logo {
    flex: unset;
}
.header-item {
    display: flex;
    flex-direction: row;
}
.nav-item1 {
    width: 300px;
    justify-content: space-around;
}
.nav-item3 {
    width: 300px;
    justify-content: space-between;
}
.search-field {
    width:100%;
    max-width:130px;
    border: 2px solid #ccc;
    border-radius: 4px;
    font-size: 16px;
    background-color: rgba(255, 255, 255, 0.3);
    background-image: url('https://cdn.rawgit.com/encharm/Font-Awesome-SVG-PNG/b7f74631/black/png/24/search.png');
    background-position: 3px 3px;
    background-repeat: no-repeat;
    padding: 6px 20px 6px 40px;
    transition: max-width 0.4s ease-in-out;
}

.search-field.expand{
    max-width:500px;
}

.sign {
    display: flex;
    flex-direction: row;
}
.sign-in {
    margin-left: auto;
    padding: 5px;
    border: 3px solid rgba(255, 255, 255, 0.75);
    border-right-width: 0px;
    border-top-left-radius: 5px;
    border-bottom-left-radius: 5px;
}
.sign-up {
    margin-left: auto;
    padding: 5px;
    border: 3px solid rgba(255, 255, 255, 0.75);
    border-top-right-radius: 5px;
    border-bottom-right-radius: 5px;
}

.div-title {
    width: 50vw;
    position: absolute;
    margin-left: 20vw;
    margin-top: 75px;
    color: grey;
}
.posts {
    width: 50vw;
    position: absolute;
    margin-left: 20vw;
    margin-top: 125px;
}
.post {
    width: 100%;
    height: 25vh;
    border: 1px solid #F2F2F2;
    margin-bottom: 20px;
    /*box-shadow: 0px 0px 5px #888888;*/
}
.post > .profile {
    z-index: 2;
    position: absolute;
    margin-top: 7vh;
    margin-left: 20px;
}
.post > .title {
    font-family: 'Roboto Slab', serif;
    font-size: 1.5em;
    margin-left: 100px;
    margin-top: 15px;
}
.post > .content {
    margin-left: 100px;
    margin-top: 10px;
}

＆＃13;

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="top" role="banner">
            <div class="container">
                <div class="nav-item1 header-item">
                    <div class="logo">Logo</div>
                    <div class="search">
                        <input type="text" class="search-field" name="search" placeholder="Search...">
                    </div>
                </div>
                <div class="nav-item2 header-item">
                    <ul class="nav">
                        <li class="nav-item">New</li>
                        <li class="nav-item">Home</li>
                        <li class="nav-item">Explore</li>
                    </ul>
                </div>
                <div class="nav-item3 header-item">
                    <div class="sign">
                        <div class="sign-in">Sign In</div>
                        <div class="sign-up">Sign Up</div>
                    </div>
                </div>

            </div>
        </div>

＆＃13;

Answer 2

我在.search（搜索字段的容器）中添加了宽度限制。这将强制输入相对于.search进行缩放。

.search {
  width:calc(100% - 40px);
}

＆＃13;

$(".search-field").focus(function () {
    $(this).animate({ "width": "100%" }, "slow" );

    // $(".logo").fadeOut();
});
$(".search-field").focusout(function () {
    $(this).animate({ "width": "130px" }, "slow" );
    // $(".logo").fadeIn();
});

＆＃13;

@import url('https://fonts.googleapis.com/css?family=Roboto+Slab');
/*! HTML5 Boilerplate v5.3.0 | MIT License | https://html5boilerplate.com/ */

/*
 * What follows is the result of much research on cross-browser styling.
 * Credit left inline and big thanks to Nicolas Gallagher, Jonathan Neal,
 * Kroc Camen, and the H5BP dev community and team.
 */

/* ==========================================================================
   Base styles: opinionated defaults
   ========================================================================== */

html {
    color: #222;
    font-size: 1em;
    line-height: 1.4;
    z-index: 1;
}

/*
 * Remove text-shadow in selection highlight:
 * https://twitter.com/miketaylr/status/12228805301
 *
 * These selection rule sets have to be separate.
 * Customize the background color to match your design.
 */

::-moz-selection {
    background: #b3d4fc;
    text-shadow: none;
}

::selection {
    background: #b3d4fc;
    text-shadow: none;
}

/*
 * A better looking default horizontal rule
 */

hr {
    display: block;
    height: 1px;
    border: 0;
    border-top: 1px solid #ccc;
    margin: 1em 0;
    padding: 0;
}

/*
 * Remove the gap between audio, canvas, iframes,
 * images, videos and the bottom of their containers:
 * https://github.com/h5bp/html5-boilerplate/issues/440
 */

audio,
canvas,
iframe,
img,
svg,
video {
    vertical-align: middle;
}

/*
 * Remove default fieldset styles.
 */

fieldset {
    border: 0;
    margin: 0;
    padding: 0;
}

/*
 * Allow only vertical resizing of textareas.
 */

textarea {
    resize: vertical;
}

/* ==========================================================================
   Browser Upgrade Prompt
   ========================================================================== */

.browserupgrade {
    margin: 0.2em 0;
    background: #ccc;
    color: #000;
    padding: 0.2em 0;
}

/* ==========================================================================
   Author's custom styles
   ========================================================================== */

















/* ==========================================================================
   Helper classes
   ========================================================================== */

/*
 * Hide visually and from screen readers
 */

.hidden {
    display: none !important;
}

/*
 * Hide only visually, but have it available for screen readers:
 * http://snook.ca/archives/html_and_css/hiding-content-for-accessibility
 */

.visuallyhidden {
    border: 0;
    clip: rect(0 0 0 0);
    height: 1px;
    margin: -1px;
    overflow: hidden;
    padding: 0;
    position: absolute;
    width: 1px;
}

/*
 * Extends the .visuallyhidden class to allow the element
 * to be focusable when navigated to via the keyboard:
 * https://www.drupal.org/node/897638
 */

.visuallyhidden.focusable:active,
.visuallyhidden.focusable:focus {
    clip: auto;
    height: auto;
    margin: 0;
    overflow: visible;
    position: static;
    width: auto;
}

/*
 * Hide visually and from screen readers, but maintain layout
 */

.invisible {
    visibility: hidden;
}

/*
 * Clearfix: contain floats
 *
 * For modern browsers
 * 1. The space content is one way to avoid an Opera bug when the
 *    `contenteditable` attribute is included anywhere else in the document.
 *    Otherwise it causes space to appear at the top and bottom of elements
 *    that receive the `clearfix` class.
 * 2. The use of `table` rather than `block` is only necessary if using
 *    `:before` to contain the top-margins of child elements.
 */

.clearfix:before,
.clearfix:after {
    content: " "; /* 1 */
    display: table; /* 2 */
}

.clearfix:after {
    clear: both;
}

/* ==========================================================================
   EXAMPLE Media Queries for Responsive Design.
   These examples override the primary ('mobile first') styles.
   Modify as content requires.
   ========================================================================== */

@media only screen and (min-width: 35em) {
    /* Style adjustments for viewports that meet the condition */
}

@media print,
       (-webkit-min-device-pixel-ratio: 1.25),
       (min-resolution: 1.25dppx),
       (min-resolution: 120dpi) {
    /* Style adjustments for high resolution devices */
}

/* ==========================================================================
   Print styles.
   Inlined to avoid the additional HTTP request:
   http://www.phpied.com/delay-loading-your-print-css/
   ========================================================================== */

@media print {
    *,
    *:before,
    *:after,
    *:first-letter,
    *:first-line {
        background: transparent !important;
        color: #000 !important; /* Black prints faster:
                                   http://www.sanbeiji.com/archives/953 */
        box-shadow: none !important;
        text-shadow: none !important;
    }

    a,
    a:visited {
        text-decoration: underline;
    }

    a[href]:after {
        content: " (" attr(href) ")";
    }

    abbr[title]:after {
        content: " (" attr(title) ")";
    }

    /*
     * Don't show links that are fragment identifiers,
     * or use the `javascript:` pseudo protocol
     */

    a[href^="#"]:after,
    a[href^="javascript:"]:after {
        content: "";
    }

    pre,
    blockquote {
        border: 1px solid #999;
        page-break-inside: avoid;
    }

    /*
     * Printing Tables:
     * http://css-discuss.incutio.com/wiki/Printing_Tables
     */

    thead {
        display: table-header-group;
    }

    tr,
    img {
        page-break-inside: avoid;
    }

    img {
        max-width: 100% !important;
    }

    p,
    h2,
    h3 {
        orphans: 3;
        widows: 3;
    }

    h2,
    h3 {
        page-break-after: avoid;
    }
}
/* ==========================================================================
   Real CSS
   ========================================================================== */
body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
    font-size: 14px;
    line-height: 1.5;
}
.top {
    position: fixed;
    height: 50px;
    /*padding: 12px;*/
    width: 100vw;
    background-color: #24292e;
    color: rgba(255, 255, 255, 0.75);
    z-index: 10;
}
.container {
    padding-top: 2px;
    width: 980px;
    margin-right: auto;
    margin-left: auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.nav {
    list-style: none;
    padding-left: 0;
    margin-top: 0;
    margin-bottom: 0
}
.nav-item {
    padding: 12px;
    float: left;
    list-style: none;
}
.logo {
    flex: unset;
}
.header-item {
    display: flex;
    flex-direction: row;
}
.nav-item1 {
    width: 300px;
    justify-content: space-around;
}
.nav-item3 {
    width: 300px;
    justify-content: space-between;
}
.search-field {
    width: 130px;
    border: 2px solid #ccc;
    border-radius: 4px;
    font-size: 16px;
    background-color: rgba(255, 255, 255, 0.3);
    background-image: url('https://cdn.rawgit.com/encharm/Font-Awesome-SVG-PNG/b7f74631/black/png/24/search.png');
    background-position: 3px 3px;
    background-repeat: no-repeat;
    padding: 6px 20px 6px 40px;
    transition: width 0.4s ease-in-out;
}

.sign {
    display: flex;
    flex-direction: row;
}
.sign-in {
    margin-left: auto;
    padding: 5px;
    border: 3px solid rgba(255, 255, 255, 0.75);
    border-right-width: 0px;
    border-top-left-radius: 5px;
    border-bottom-left-radius: 5px;
}
.sign-up {
    margin-left: auto;
    padding: 5px;
    border: 3px solid rgba(255, 255, 255, 0.75);
    border-top-right-radius: 5px;
    border-bottom-right-radius: 5px;
}

.div-title {
    width: 50vw;
    position: absolute;
    margin-left: 20vw;
    margin-top: 75px;
    color: grey;
}
.posts {
    width: 50vw;
    position: absolute;
    margin-left: 20vw;
    margin-top: 125px;
}
.post {
    width: 100%;
    height: 25vh;
    border: 1px solid #F2F2F2;
    margin-bottom: 20px;
    /*box-shadow: 0px 0px 5px #888888;*/
}
.post > .profile {
    z-index: 2;
    position: absolute;
    margin-top: 7vh;
    margin-left: 20px;
}
.post > .title {
    font-family: 'Roboto Slab', serif;
    font-size: 1.5em;
    margin-left: 100px;
    margin-top: 15px;
}
.post > .content {
    margin-left: 100px;
    margin-top: 10px;
}
.search {
  width:calc(100% - 40px);
}

＆＃13;

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="top" role="banner">
            <div class="container">
                <div class="nav-item1 header-item">
                    <div class="logo">Logo</div>
                    <div class="search">
                        <input type="text" class="search-field" name="search" placeholder="Search...">
                    </div>
                </div>
                <div class="nav-item2 header-item">
                    <ul class="nav">
                        <li class="nav-item">New</li>
                        <li class="nav-item">Home</li>
                        <li class="nav-item">Explore</li>
                    </ul>
                </div>
                <div class="nav-item3 header-item">
                    <div class="sign">
                        <div class="sign-in">Sign In</div>
                        <div class="sign-up">Sign Up</div>
                    </div>
                </div>

            </div>
        </div>

＆＃13;

在使用flexboxes和动画时遇到问题

2 个答案: