css焦点图制作

使用纯CSS制作焦点图

通过CSS的动画和过渡效果实现简单焦点图轮播，无需JavaScript。以下是一个基础实现方案：

<div class="slider">
  <div class="slides">
    <div class="slide">Slide 1</div>
    <div class="slide">Slide 2</div>
    <div class="slide">Slide 3</div>
  </div>
</div>

.slider {
  width: 100%;
  overflow: hidden;
  position: relative;
}

.slides {
  display: flex;
  width: 300%; /* 3 slides */
  animation: slide 10s infinite;
}

.slide {
  width: 33.33%;
  height: 300px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  color: white;
}

.slide:nth-child(1) { background: #3498db; }
.slide:nth-child(2) { background: #e74c3c; }
.slide:nth-child(3) { background: #2ecc71; }

@keyframes slide {
  0% { transform: translateX(0); }
  33% { transform: translateX(-33.33%); }
  66% { transform: translateX(-66.66%); }
  100% { transform: translateX(0); }
}

结合HTML和CSS3过渡效果

实现带过渡动画的焦点图，可通过:target伪类实现手动切换：

<div class="slider">
  <div class="slides">
    <div id="slide1" class="slide">Slide 1</div>
    <div id="slide2" class="slide">Slide 2</div>
    <div id="slide3" class="slide">Slide 3</div>
  </div>

  <div class="controls">
    <a href="#slide1">1</a>
    <a href="#slide2">2</a>
    <a href="#slide3">3</a>
  </div>
</div>

.slider {
  width: 100%;
  overflow: hidden;
  position: relative;
}

.slides {
  width: 300%;
  transition: transform 0.5s ease;
}

.slide {
  width: 33.33%;
  float: left;
  height: 300px;
}

#slide1:target ~ .slides { transform: translateX(0); }
#slide2:target ~ .slides { transform: translateX(-33.33%); }
#slide3:target ~ .slides { transform: translateX(-66.66%); }

响应式焦点图设计

确保焦点图在不同设备上正常显示：

.slider {
  max-width: 1200px;
  margin: 0 auto;
}

.slide {
  height: auto;
  min-height: 200px;
}

@media (max-width: 768px) {
  .slide {
    padding: 20px;
  }
}

添加导航指示器

通过CSS伪元素创建视觉指示器：

.controls a {
  display: inline-block;
  width: 15px;
  height: 15px;
  border-radius: 50%;
  background: #ccc;
  margin: 0 5px;
  position: relative;
}

.controls a.active::after {
  content: '';
  position: absolute;
  width: 9px;
  height: 9px;
  background: #333;
  border-radius: 50%;
  top: 3px;
  left: 3px;
}

性能优化建议

避免使用可能引起重排的CSS属性：

.slides {
  will-change: transform;
  backface-visibility: hidden;
}

.slide {
  contain: layout paint style;
}

以上方案可根据实际需求组合使用或扩展功能，如添加淡入淡出效果、缩略图导航等高级特性。