`CSS`学习

选择器

/*元素选择器*/
html {
}

/*类选择器*/
.gray {
}

/*id选择器*/
#unique {
}

/*伪类选择器*/
a:hover {
}

/*伪元素选择器*/
ul ::marker {
}

/*运算符选择器 选择了<article>元素的初代子元素*/
article > p {
}

字体设置

常用几个如下：其它的font开头的省略

px

body {
    font-size: 22px;
    font-family: Arial, Helvetica, sans-serif;
    font-weight: 300;
}

em rem

h1 {
    border: 2px dashed red;
    width: 50%;
    /* rem base the root element
and em base the itself fontsize */
    font-size: 3rem;
    padding: 0.5em;
}

如何使用外部字体

@import url('https://fonts.googleapis.com/css2?family=Roboto&display=swap');

body {
    padding: 25%;
    font-size: 2rem;
}

/* input, button {
    font: inherit;
} */

p {
 /*    text-transform: capitalize;
    text-align: right; */
    /* text-indent: 2em; */

    /* line-height: 1.5; */
    /* letter-spacing: 0.1em; */
    /* word-spacing: 0.1em; */
    /* font-weight: 900; */
    /* font-style: italic; */
    /* font-family: 'Courier New', Courier, monospace; */
    font-family: 'Roboto', sans-serif;
}

盒子设置

box-sizing: content-box;：这是默认值。在这种模型下，

元素的宽度和高度仅包括内容区域，不包括边框（border）、

内边距（padding）和外边距（margin）。这是传统的盒模型。

box-sizing: border-box;：在这种模型下，

元素的宽度和高度包括了内容区域、边框和内边距，

但不包括外边距。

h1 {
    box-sizing: border-box;
    border: 2px dashed red;
}

.container {
  border: 10px double red;
  font-size: 1.5rem;
  /*  margin-top: 1.5em;
    margin-right: 2em;
    margin-bottom: 2em;
    margin-left: 2em; */

  /* margin: 1.5em 2em 2em; */
  /* define the top right bottom left margin */
  /* margin: 1em 2em 3em 4em; */
  margin: 1.5em;
  padding: 1.5em;
  /* 
    border-top: 5px solid red;
    border-right: 10px dotted green; */
  outline: 5px solid purple;
  outline-offset: -20px;
}

画圆

<div class="circle"></div>

.circle {
  margin: 3rem auto;
  background-color: gold;
  width: 100px;
  height: 100px;
  border: 2px solid black;
  outline: 2px solid red;
  outline-offset: 0.25rem;
  border-radius: 50%;
}

设置颜色

/*  you can change the hover or focus color by changing the hue or transparent, or opacity */
a:hover, a:focus {
    /* color: hsl(189, 44%, 49%) */
    color: hsl(207, 44%, 49%, 0.8)
    /* opacity: 0.8; */
}

列表操作

ol {
  list-style-type: lower-alpha;
  padding: 0;
}

ul {
  list-style-type: square;
  list-style-position: inside;
  /* list-style-image: url('../images/checkmark.png'); */
  /* list-style: square url('../images/checkmark.png') inside; */

  text-align: center;
  color: #00f;
  line-height: 1.6;
}

ul li:nth-child(even) {
  color: red;
}

ul ::marker {
  color: red;
  font-family: fantasy;
  font-size: 1em;
  content: "ONLY $5 >> "
}

对链接样式

li a {
  display: block;
}

li a,
li a:visited {
  text-decoration: none;
  color: #333;
}

li a:hover,
li a:focus {
  background-color: #333;
  color: whitesmoke;
  cursor: pointer;
}

li:last-child a {
  border-radius: 0 0 2rem 2rem;
}

文字

排版样式

.left {
  float: left;
  margin-right: 1rem;
}

.right {
  float: right;
  margin-left: 1rem;
}

.clear {
  clear: both;
}

section {
  background-color: bisque;
  border: 1px solid #333;
  padding: 1rem;
  /*  fix element overflow section block */
  /*  fix element overflow section block */
  /* overflow: auto; */
  display: flow-root;
}

.columns {
 /*  column-count: 4;
  column-width: 250px; */
  columns: 4 250px;
  column-rule:  3px solid #000;
  column-gap: 3rem;
}

.columns p {
  margin-top: 0;
}

.columns h2 {
 margin-top: 0;
 background-color: #333;
 color: white;
 padding: 1rem;
 break-inside: avoid;
 /* break-before: column; */
}

.columns .quote {
  margin-top: 2rem;
  font-size: 3rem;
  text-align: center;
  color: #333;
  column-span: all;
}

.nowrap {
  white-space: nowrap;
}

position 使用

.absolute {
  background-color: #00f;
  position: absolute;
  top: 0;
  left: 0;
  /* adjust the element layer 1 to set the top of others */
  z-index: 1;
}

.relative {
  background-color: #f00;
  position: relative;
  top: 300px;
  left: 100px;
}

.fixed {
  background-color: green;
  position: fixed;
  top: 100px;
}

footer {
  background-color: #000;
  position: sticky;
  bottom: 0;
  font-size: 3rem;
}

flex使用

.container {
  max-width: 800px;
  min-height: 400px;
  margin-inline: auto;
  border: 1px solid #000;
  display: flex;
  gap: 1rem;
  justify-content: center;
  align-items: center;
  flex-flow: row wrap;
  align-content: space-evenly;
} 

.box {
  /* min-width: 100px; */
  height: 100px;
  background-color: #000;
  color: #fff;
  font-size: 2rem;
  padding: 0.5rem;

  display: flex;
  justify-content: center; 
  align-items: center;

  flex: 1 1 150px;
}

.box:nth-child(2) {
  flex: 2 2 150px;
  order: 1;
}

`grid`使用

<body>
    <header class="header el"><h1>Header</h1></header>
    <main class="container">
        <div class="box">1</div>
        <div class="box">2</div>
        <div class="box">3</div>
        <div class="box">4</div>
        <div class="box">5</div>
        <div class="box">6</div>
    </main>
    <aside class="sidebar el"><h2>Sidebar</h2></aside>
    <footer class="footer el"><h2>Footer</h2></footer>
</body>

body {
  font-family: "Roboto", sans-serif;
  min-height: 100vh;

  display: grid;
  grid-template-columns: repeat(9, 1fr);
  grid-auto-rows: 50px auto 50px;
  grid-template-areas: 
    "hd hd hd hd hd hd hd hd hd" 
    "mn mn mn mn mn mn mn sb sb"
    "ft ft ft ft ft ft ft ft ft";
    column-gap: 0.5rem;
}

.header {
  grid-area: hd;
}

.sidebar {
  grid-area: sb;
  background-color: #00f;
}

.footer {
  grid-area: ft;
}

.container {
  grid-area: mn;
  min-height: 400px;
  display: grid;
  grid-template-columns: repeat(2, 1fr 2fr);
  grid-auto-rows: minmax(150px, auto);
  gap: 1rem;
}

.el {
  background-color: rebeccapurple;
  color: #fff;
  display: grid;
  place-content: center;
}

.box {
  background-color: #000;
  color: #fff;
  font-size: 2rem;
  padding: 0.5rem;
}

.box:first-child {
  background-color: #00f;
  grid-column: 1 / 4;
  grid-row: 1 / 3;

  display: grid;
  place-content: center;
}

.box:nth-child(2) {
  background-color: purple;
/*   grid-column: 1 / 5;
  grid-row: 3 / 4; */
  grid-area: 3 / 1 / 4 / 5;
}

`URL`使用

<body>
    <!-- <div class="container">
        <section class="hero">
            <figure class="profile-pic-figure">
                <img src="img/profile-800x800.png" alt="Profile Picture" title="My Profile Picture" width="800" height="800">
                <figcaption class="offscreen">Jane Doe</figcaption>
            </figure>
            <h1 class="h1">
                <span class="nowrap">Hello 👋</span> 
                <span class="nowrap">I'm Jane</span>
            </h1>
        </section>
    </div> -->
    <!-- <section class="example">
       
            <img src="img/pat1.png" alt="Pattern 1" width="200" height="200">
        
    </section> -->
    <section>
        <p class="clip">Jane</p>
    </section>
</body>

body {
  font-family: "Nunito", sans-serif;
  min-height: 100vh;
  background-color: aliceblue;
  /* background-image: url("../img/bubbles.png"), linear-gradient(to left, steelblue, #fff);
  background-repeat: repeat-y, no-repeat;
  background-position: right center; */
  
  background: repeat-y right center url("../img/bubbles.png"), no-repeat linear-gradient(to left, steelblue, #fff);
  background-size: 20%, auto;
}

.container {
  background-color: rgb(251, 210, 156);
  background-image: url('../img/map-2176x1451.png');
  background-repeat: no-repeat;
  background-position: top;
  background-size: cover;
}

.hero {
  border-bottom: 2px solid #000;
  padding: 20px;
  display: flex;
  justify-content: flex-start;
  align-items: center;
  gap: 30px;

  background-color: hsla(0, 0%, 100%, 0.35);

}

.h1 {
  font-size: 500%;
  color: aliceblue;
  text-shadow: 2px 2px 5px #000;
  /* background-color: hsla(0, 0%, 0%, 0.403);
  padding: 0.25rem;
  border-radius: 10px; */
}

.profile-pic-figure {
  width: 35%;
}

.profile-pic-figure img {
  width: 100%;
  height: auto;
  min-width: 100px;
  border: 5px double gray;
  border-radius: 50%;
}

.example {
  margin-top: 1rem;
  padding-left: 20px;
  border: 1px solid red;
}

.example img {
  width: 25%;
  height: auto;
}

.clip {
  font-weight: 800;
  font-size: 18rem;
  text-align: center;
  background-image: url("../img/scenic-2200x1331.png");
  background-size: 100%;
  text-transform: uppercase;
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

`Media`使用

<body>
    <header>
      <h1>Our Staff</h1>
      <nav>
        <a href="#profile1">Joe</a>
        <a href="#profile2">Matt</a>
        <a href="#profile3">Jane</a>
      </nav>
    </header>

    <main>
      <article id="profile1" class="card">
        <figure>
          <img
            src="img/profile1-500x500.png"
            alt="Joe Coder"
            width="500"
            height="500"
          />
          <figcaption>Joe Coder</figcaption>
        </figure>
        <p><q>I code stuff.</q></p>
      </article>
      <article id="profile2" class="card">
        <figure>
          <img
            src="img/profile2-500x500.png"
            alt="Matt Designer"
            width="500"
            height="500"
          />
          <figcaption>Matt Designer</figcaption>
        </figure>
        <p><q>I design stuff.</q></p>
      </article>
      <article id="profile3" class="card">
        <figure>
          <img
            src="img/profile3-500x500.png"
            alt="Jane Dev Rel"
            width="500"
            height="500"
          />
          <figcaption>Jane <span class="nowrap">Dev Rel</span></figcaption>
        </figure>
        <p><q>I teach stuff.</q></p>
      </article>
    </main>

    <footer>
      <p>&copy; Acme Co.</p>
    </footer>
  </body>

@import url("https://fonts.googleapis.com/css2?family=Nunito&display=swap");

/* || RESET */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

img {
  display: block;
  max-width: 100%;
  height: auto;
}

/* || UTILITY CLASSES */
.nowrap {
  white-space: nowrap;
}

/* || GENERAL STYLES */
html {
  scroll-behavior: smooth;
}

body {
  font: 1.5rem "Nunito", sans-serif;
  min-height: 100vh;
  background-color: #475569;
  background-image: radial-gradient(whitesmoke, #475569);
  display: flex;
  flex-direction: column;
}

header,
footer {
  position: sticky;
  background-color: #1e293b;
  color: whitesmoke;
  text-align: center;
}

header {
  top: 0;
}

nav {
  background-color: #fff;
  padding: 0.5rem;
  border-bottom: 2px solid #000;
  font-weight: bolder;
  display: flex;
  justify-content: space-evenly;
}

nav a:link,
nav a:visited {
  color: #000;
}

nav a:hover,
nav a:focus {
  color: hsla(0, 0%, 20%, 0.6);
}

main {
  flex-grow: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.5rem;
  padding: 1rem;
}

footer {
  bottom: 0;
}

/* || PROFILE CARD */
.card {
  scroll-margin-top: 8rem;
  width: min(100%, 350px);
  background-color: #cbd5e1;
  border: 2px solid #000;
  border-radius: 15px;
  padding: 1rem;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.card figure {
  display: flex;
  flex-flow: column nowrap;
}

.card img {
  border: 5px double #333;
  border-radius: 50%;
}

.card figcaption {
  font-weight: bolder;
  font-size: 2rem;
  margin: 1rem;
  text-align: center;
}

/* || SMALL */
@media screen and (min-width: 576px) {
  main {
    justify-content: center;
    flex-flow: row wrap;
    padding: 1rem;
  }
  .card {
    width: min(100%, 400px);
  }
  .card:last-child {
    order: -1;
  }
}

/* || MEDIUM */
@media screen and (min-width: 768px) {
  nav {
    display: none;
  }
  .card {
    width: min(100%, 325px);
  }
  .card figure {
    flex-flow: column-reverse;
  }
  .card p {
    margin-top: 1rem;
  }
}

/* || LARGE */
@media screen and (min-width: 992px) {
  .card {
    width: min(100%, 400px);
  }
  .card:nth-child(2) {
    order: -1;
  }
}

/* || XL  */
@media screen and (min-width: 1200px) {
  .card {
    width: min(calc(33% - 1rem), 500px);
  }
}

/* || MOBILE DEVICE LANDSCAPE  */
@media screen and (max-height: 425px) and (min-aspect-ratio: 7/4) {
  h1 {
    font-size: 1.5rem;
  }

  nav {
    display: none;
  }

  main {
    flex-flow: row nowrap;
    justify-content: space-evenly;
    align-items: stretch;
  }

  .card {
    width: min(calc(33% - 0.25rem), 200px);
  }

  .card figcaption,
  .card p {
    font-size: 1.25rem;
  }
}

function 用法

:root {
  /* FONT */
  --FF: "Nunito", sans-serif;
  --FS: clamp(1.75rem, 3vh, 2.25rem);
  --FS-SM: clamp(1.25rem, 2vh, 1.5rem);
  --FS-XL: 3rem;

  /* COLOR */
  --BGCOLOR: #475569;
  --ALT-BGCOLOR: #1E293B;
  --RADIAL-COLOR: whitesmoke;
  --LIGHT-COLOR: whitesmoke;
  --DARK-COLOR: #000;

  /* SQUARE */
  --SQUARE-BGCOLOR: papayawhip;
  --SQUARE-SIZE: max(150px, 20vw);

  /* GENERAL */
  --PADDING: 0.5em;
  --SHADOWS: 0 6px 5px -5px var(--DARK-COLOR);
  --BORDERS: 2px solid var(--DARK-COLOR);
}
h1 {
    gap: min(4vw, 15px);
    font-size: var(--FS-XL);
    background-image: radial-gradient(var(--RADIAL-COLOR), var(--BGCOLOR));
}

选择器​

字体设置​

盒子设置​

设置颜色​

列表操作​

对链接样式​

文字​

排版样式​

position 使用​

grid使用​

URL使用​

Media使用​

选择器

字体设置

盒子设置

设置颜色

列表操作

对链接样式

文字

排版样式

position 使用

`grid`使用

`URL`使用

`Media`使用