html - 了解如何在简单的 SVG 中创建蜡烛火焰

Question

我只是在看一个简单的 SVG 蛋糕动画 HERE ，CSS 代码如下所示:

@import url(http://fonts.googleapis.com/css?family=Lato:300italic);

html,
body {
  width: 100%;
  height: 100%;
}

body {
  background: #ee9ca7;
}

#cake {
  display: block;
  position: relative;
  margin: -10em auto 0 auto;
}

*/* ============================================== Candle
*/
.velas {
  background: #ffffff;
  border-radius: 10px;
  position: absolute;
  top: 228px;
  left: 50%;
  margin-left: -2.4px;
  margin-top: -8.33333333px;
  width: 5px;
  height: 35px;
  transform: translateY(-300px);
  backface-visibility: hidden;
  animation: in 500ms 6s ease-out forwards;
}
.velas:after,
.velas:before {
  background: rgba(255, 0, 0, 0.4);
  content: "";
  position: absolute;
  width: 100%;
  height: 2.22222222px;
}
.velas:after {
  top: 25%;
  left: 0;
}
.velas:before {
  top: 45%;
  left: 0;
}
/* ============================================== Fire
*/
.fuego {
  border-radius: 100%;
  position: absolute;
  top: -20px;
  left: 50%;
  margin-left: -2.6px;
  width: 6.66666667px;
  height: 18px;
}
.fuego:nth-child(1) {
  animation: fuego 2s 6.5s infinite;
}
.fuego:nth-child(2) {
  animation: fuego 1.5s 6.5s infinite;
}
.fuego:nth-child(3) {
  animation: fuego 1s 6.5s infinite;
}
.fuego:nth-child(4) {
  animation: fuego 0.5s 6.5s infinite;
}
.fuego:nth-child(5) {
  animation: fuego 0.2s 6.5s infinite;
}
/* ============================================== Animation Fire
*/
@keyframes fuego {
  0%, 100% {
    background: rgba(254, 248, 97, 0.5);
    box-shadow: 0 0 40px 10px rgba(248, 233, 209, 0.2);
    transform: translateY(0) scale(1);
  }
  50% {
    background: rgba(255, 50, 0, 0.1);
    box-shadow: 0 0 40px 20px rgba(248, 233, 209, 0.2);
    transform: translateY(-20px) scale(0);
  }
}
@keyframes in {
  to {
    transform: translateY(0);
  }
}
.text {
  color: #8b6a60;
  font-family: 'Lato', sans-serif;
  font-weight: 300;
  font-style:italic;
  text-align: center;
  h1 {
    font-size: 1.4em;
  }
}

稍微检查一下代码后，我开始知道蜡烛火焰是由这组 HTML 元素引起的:

    <div class="velas">
                    <div class="fuego"></div>
                    <div class="fuego"></div>
                    <div class="fuego"></div>
                    <div class="fuego"></div>
                    <div class="fuego"></div>
   </div>

此 HTML 具有以下 CSS 代码:

  background: #ffffff;
  border-radius: 10px;
  position: absolute;
  top: 228px;
  left: 50%;
  margin-left: -2.4px;
  margin-top: -8.33333333px;
  width: 5px;
  height: 35px;
  transform: translateY(-300px);
  backface-visibility: hidden;
  animation: in 500ms 6s ease-out forwards;
}
.velas:after,
.velas:before {
  background: rgba(255, 0, 0, 0.4);
  content: "";
  position: absolute;
  width: 100%;
  height: 2.22222222px;
}
.velas:after {
  top: 25%;
  left: 0;
}
.velas:before {
  top: 45%;
  left: 0;
}

/* ============================================== Fire
*/

.fuego {
  border-radius: 100%;
  position: absolute;
  top: -20px;
  left: 50%;
  margin-left: -2.6px;
  width: 6.66666667px;
  height: 18px;
}
.fuego:nth-child(1) {
  animation: fuego 2s 6.5s infinite;
}
.fuego:nth-child(2) {
  animation: fuego 1.5s 6.5s infinite;
}
.fuego:nth-child(3) {
  animation: fuego 1s 6.5s infinite;
}
.fuego:nth-child(4) {
  animation: fuego 0.5s 6.5s infinite;
}
.fuego:nth-child(5) {
  animation: fuego 0.2s 6.5s infinite;
}

/* ============================================== Animation Fire
*/

@keyframes fuego {
  0%, 100% {
    background: rgba(254, 248, 97, 0.5);
    box-shadow: 0 0 40px 10px rgba(248, 233, 209, 0.2);
    transform: translateY(0) scale(1);
  }
  50% {
    background: rgba(255, 50, 0, 0.1);
    box-shadow: 0 0 40px 20px rgba(248, 233, 209, 0.2);
    transform: translateY(-20px) scale(0);
  }
}

@keyframes in {
  to {
    transform: translateY(0);
  }
}

现在我看不到实际上引起红色和黄色火焰的 CSS 代码，我相信白色阴影是由动画中给出的非常高的框阴影引起的，但不知何故我看不到蜡烛在哪里火焰被创造出来，有人能指导我蜡烛火焰是在哪里真正创造出来的吗？

Answer 1

颜色由 RGB 值设置。有黄色、红色和一些粉红色。

@keyframes fuego {
  0%, 100% {
    background: rgba(254, 248, 97, 0.5); /* yellow */
    box-shadow: 0 0 40px 10px rgba(248, 233, 209, 0.2); /* pink */
    transform: translateY(0) scale(1);
  }
  50% {
    background: rgba(255, 50, 0, 0.1); /* red */
    box-shadow: 0 0 40px 20px rgba(248, 233, 209, 0.2); /* pink again */
    transform: translateY(-20px) scale(0);
  }
}

更改颜色的时间设置在 .fuego:nth-child(1) 到 .fuego:nth-child(6)