css - 背景图片不会立即加载

Question

我正在尝试制作一个汉堡包菜单，其形状为……一个真正的汉堡包。 我唯一的小问题与扩展菜单上的“芝麻”背景图像有关。我设法找到了一个使用径向渐变图像的片段当您单击菜单图标并且菜单下拉时，白色圆点背景图像直到过渡完成后才会显示。

我特别关注的代码是 #menuList 选择器上的背景图像行。

body {
  margin: 0;
  padding: 0;
  font-family: 'Open Sans', sans-serif;
}

a {
  text-decoration: none; /* no underlines */
}

#menuToggle {
  display: block;
  position: absolute;
  height: 36px;
  width: 36px;
  top: 20px;
  right: 20px;
  z-index: 1;
  color: #e5cb7a;
  
  -webkit-user-select: none;
  user-select: none; /* don't let 'em select text */
}

/* Style the "checkbox" used to activate the hamburger menu */
#menuToggle input {
  display: block;
  position: absolute;
  height: 32px;
  width: 32px;
  top: -7px;
  right: -7px;
  cursor: pointer; /* make the burger pointy */
  opacity: 0; /* hide the checkbox */
  z-index: 2;
}

/* Make the menu look like a triangle shape by adding a thick border next to it. */
#menuToggle::before {
  content: '';
  position: absolute;
  top: -10px;
  right: -10px;
  border-color: #e5cb7a; /* Bun-color */
  border-style: solid;
  border-width: 22px;
  border-radius: 8px;
}

/* Style the three spans that make up the hamburger */
#menuToggle span {
  display: block;
  position: relative;
  height: 4px;
  width: 30px;
  margin: 0px 0px 6px 9px;
  border-radius: 3px;
  
  z-index: 1;
  
  transition: transform 0.5s,
              opacity 0.55s ease;
}

/* Color the top span a lettuce color */
#topBun {
  background: #32c704;
}

/* Color the middle span a burger color */
#meat {
  background: #450101;
}

/* Color the bottom span a ketchup color */
#bottomBun {
  background: #ec3521;
}

/* Move the top bun down 10px (its height), then turn it */
#menuToggle input:checked ~ #topBun {
  background: #450101;
  transform: translate(0px, 10px) rotate(45deg);
}

#menuToggle input:checked ~ #meat {
  opacity: 0;
  transform: rotate(0deg);
}

/* Move the bottom bun up 10px (its height), then turn it */
#menuToggle input:checked ~ #bottomBun {
  background: #450101;
  transform: translate(0px,-10px) rotate(-45deg);
}

#menuList {
  display: inline-block;
  position: absolute;
  top: 0px;
  right: 0px;
  height: 100px;
  width: 100px;
  margin: -20px -20px 0 0;
  padding: 50px 90px 0 0;
  background: transparent;
  list-style-type: none; /* no bullets, weapon-free zone */
  /*-webkit-font-smoothing: antialiased;*/
  
  /* Sesame seeds for the top bun of the expanded menu */
  background-image: radial-gradient(white 20%, transparent 0);
  background-size: 15px 12px;
  background-position: 0 12px, 10px 10px;
  
  /* Shrink the actual menu list until the hamburger is opened */
  transform: translate(0px,-65px) scale(1,0.00001);
  transition: transform 1.5s, background 1.5s;
}

/* Make a larger burger bun shape around the expanded hamburger menu */
#menuList::before {
  content: '';
  position: absolute;
  top: 10px;
  right: 10px;
  border-style: solid;
  border-width: 90px;
  border-radius: 10px;
  z-index: -1;
}

#menuList li {
  padding: 3px 5px;
  font-size: 22px;
  text-align: center;
  width: 170px;
  color: #ffffff;
}

#menuList li:hover {
  font-weight: bold;
  letter-spacing: 2px;
}

/* Color the first menu option a lettuce color */
#about {
  background: #32c704;
}

/* Color the second menu option a burger color */
#info {
  background: #450101;
}

/* Color the third menu option a ketchup color */
#contact {
  background: #ec3521;
}

/* Transform the list back to its normal "visible" size when the input is checked */
#menuToggle input:checked ~ ul {
  transform: none;
}

<nav>
  <div id="menuToggle">
    <input type="checkbox" />
    <span id="topBun"></span>
    <span id="meat"></span>
    <span id="bottomBun"></span>
    
    <ul id="menuList">
      <a href="#"><li id="about">ABOUT</li></a>
      <a href="#"><li id="info">INFO</li></a>
      <a href="#"><li id="contact">CONTACT</li></a>
    </ul>
  </div>
</nav>

为了更好地说明问题，我放慢了这支笔的过渡速度。

如何让背景始终显示，而不是仅在菜单完全展开时显示？

CodePen

Answer 1

展开后的菜单“包子”是边框，而不是背景，而背景是折叠的汉堡包。

body {
  margin: 0;
  padding: 0;
  font-family: 'Open Sans', sans-serif;
}

a {
  text-decoration: none;
  /* no underlines */
}

#menuToggle {
  display: block;
  position: absolute;
  height: 36px;
  width: 36px;
  top: 20px;
  right: 20px;
  z-index: 1;
  color: #e5cb7a;
  -webkit-user-select: none;
  user-select: none;
  /* don't let 'em select text */
}


/* Style the "checkbox" used to activate the hamburger menu */

#menuToggle input {
  display: block;
  position: absolute;
  height: 32px;
  width: 32px;
  top: -7px;
  right: -7px;
  cursor: pointer;
  /* make the burger pointy */
  opacity: 0;
  /* hide the checkbox */
  z-index: 2;
}


/* Make the menu look like a triangle shape by adding a thick border next to it. */

#menuToggle::before {
  content: '';
  position: absolute;
  top: -10px;
  right: -10px;
  border-color: #e5cb7a;
  /* Bun-color */
  border-style: solid;
  border-width: 22px;
  border-radius: 8px;
}


/* Style the three spans that make up the hamburger */

#menuToggle span {
  display: block;
  position: relative;
  height: 4px;
  width: 30px;
  margin: 0px 0px 6px 9px;
  border-radius: 3px;
  z-index: 1;
  transition: transform 0.5s, opacity 0.55s ease;
}


/* Color the top span a lettuce color */

#topBun {
  background: #32c704;
}


/* Color the middle span a burger color */

#meat {
  background: #450101;
}


/* Color the bottom span a ketchup color */

#bottomBun {
  background: #ec3521;
}


/* Move the top bun down 10px (its height), then turn it */

#menuToggle input:checked~#topBun {
  background: #450101;
  transform: translate(0px, 10px) rotate(45deg);
}

#menuToggle input:checked~#meat {
  opacity: 0;
  transform: rotate(0deg);
}


/* Move the bottom bun up 10px (its height), then turn it */

#menuToggle input:checked~#bottomBun {
  background: #450101;
  transform: translate(0px, -10px) rotate(-45deg);
}

#menuList {
  display: inline-block;
  position: absolute;
  top: 0px;
  right: 0px;
  height: 100px;
  width: 100px;
  margin: -20px -20px 0 0;
  padding: 50px 90px 0 0;
  background: transparent;
  list-style-type: none;
  /* no bullets, weapon-free zone */
  /*-webkit-font-smoothing: antialiased;*/
  
  /* Shrink the actual menu list until the hamburger is opened */
  transform: translate(0px, -65px) scale(1, 0.00001);
  transition: transform 1.5s;
}


/* Make a larger burger bun shape around the expanded hamburger menu */

#menuList::before {
  content: '';
  position: absolute;
  top: 10px;
  right: 10px;
  bottom: -30px;
  left: 0;
  border-radius: 10px;
  z-index: -1;
  /* Sesame seeds for the top bun of the expanded menu */
  background-color: #e5cb7a;
  background-image: radial-gradient(white 20%, transparent 0);
  background-size: 15px 12px;
  background-position: 0 12px, 10px 10px;
}

#menuList li {
  padding: 3px 5px;
  font-size: 22px;
  text-align: center;
  width: 170px;
  color: #ffffff;
}

#menuList li:hover {
  font-weight: bold;
  letter-spacing: 2px;
}


/* Color the first menu option a lettuce color */

#about {
  background: #32c704;
}


/* Color the second menu option a burger color */

#info {
  background: #450101;
}


/* Color the third menu option a ketchup color */

#contact {
  background: #ec3521;
}


/* Transform the list back to its normal "visible" size when the input is checked */

#menuToggle input:checked~ul {
  transform: translate3d(0,0,0);
}

<nav>
  <div id="menuToggle">
    <input type="checkbox" />
    <span id="topBun"></span>
    <span id="meat"></span>
    <span id="bottomBun"></span>

    <ul id="menuList">
      <a href="#">
        <li id="about">ABOUT</li>
      </a>
      <a href="#">
        <li id="info">INFO</li>
      </a>
      <a href="#">
        <li id="contact">CONTACT</li>
      </a>
    </ul>
  </div>
</nav>