CSS Animation & Transition 完全指南 2026

按钮悬停效果、加载动画、页面转场……在现代网页开发中，动画是必不可少的。

学习如何仅用 CSS 就能创建流畅的交互效果，无需 JavaScript。

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Transition vs Animation

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CSS Transition

基本语法

transition: property duration timing-function delay;

基本示例

/* 单一属性 */
.button {
  background: #3b82f6;
  transition: background 0.3s ease;
}

.button:hover {
  background: #2563eb;
}

/* 多个属性 */
.card {
  transform: translateY(0);
  box-shadow: 0 4px 6px rgba(0,0,0,0.1);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 20px 40px rgba(0,0,0,0.2);
}

时间函数

/* 内置函数 */
.ease { transition-timing-function: ease; }         /* 默认 */
.linear { transition-timing-function: linear; }     /* 匀速 */
.ease-in { transition-timing-function: ease-in; }   /* 慢启动 */
.ease-out { transition-timing-function: ease-out; } /* 慢结束 */
.ease-in-out { transition-timing-function: ease-in-out; }

/* 自定义贝塞尔曲线 */
.custom { transition-timing-function: cubic-bezier(0.68, -0.55, 0.27, 1.55); }

/* 步进 */
.steps { transition-timing-function: steps(4, end); }

常用贝塞尔曲线

/* 弹跳 */
.bounce { transition: all 0.5s cubic-bezier(0.68, -0.55, 0.27, 1.55); }

/* 平滑 */
.smooth { transition: all 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94); }

/* 快速 */
.snap { transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1); }

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CSS Animation

基本语法

@keyframes 动画名称 {
  from { /* 开始状态 */ }
  to { /* 结束状态 */ }
}

/* 或者 */
@keyframes 动画名称 {
  0% { /* 开始 */ }
  50% { /* 中间 */ }
  100% { /* 结束 */ }
}

.element {
  animation: 名称 duration timing-function delay iteration-count direction fill-mode;
}

Animation 属性

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实战动画示例

1. 淡入

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

.fade-in {
  animation: fadeIn 0.5s ease forwards;
}

/* 从上方淡入 */
@keyframes fadeInDown {
  from {
    opacity: 0;
    transform: translateY(-20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.fade-in-down {
  animation: fadeInDown 0.5s ease forwards;
}

2. 加载动画

@keyframes spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

.spinner {
  width: 40px;
  height: 40px;
  border: 4px solid #e5e7eb;
  border-top-color: #3b82f6;
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

3. 脉冲效果

@keyframes pulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.05); }
}

.pulse {
  animation: pulse 2s ease-in-out infinite;
}

/* 脉冲圆环 */
@keyframes pulseRing {
  0% {
    transform: scale(0.8);
    opacity: 1;
  }
  100% {
    transform: scale(2);
    opacity: 0;
  }
}

.pulse-ring {
  position: relative;
}

.pulse-ring::before {
  content: '';
  position: absolute;
  inset: 0;
  border: 2px solid #3b82f6;
  border-radius: 50%;
  animation: pulseRing 1.5s ease-out infinite;
}

4. 弹跳

@keyframes bounce {
  0%, 100% {
    transform: translateY(0);
    animation-timing-function: cubic-bezier(0.8, 0, 1, 1);
  }
  50% {
    transform: translateY(-25%);
    animation-timing-function: cubic-bezier(0, 0, 0.2, 1);
  }
}

.bounce {
  animation: bounce 1s infinite;
}

5. 抖动（错误提示）

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  10%, 30%, 50%, 70%, 90% { transform: translateX(-5px); }
  20%, 40%, 60%, 80% { transform: translateX(5px); }
}

.shake {
  animation: shake 0.5s ease;
}

/* 用 JavaScript 触发 */
/* element.classList.add('shake'); */

6. 打字效果

@keyframes typing {
  from { width: 0; }
  to { width: 100%; }
}

@keyframes blink {
  50% { border-color: transparent; }
}

.typing {
  overflow: hidden;
  white-space: nowrap;
  border-right: 3px solid;
  width: 0;
  animation:
    typing 3s steps(30) forwards,
    blink 0.7s step-end infinite;
}

7. 骨架屏加载

@keyframes shimmer {
  0% { background-position: -200% 0; }
  100% { background-position: 200% 0; }
}

.skeleton {
  background: linear-gradient(
    90deg,
    #f0f0f0 25%,
    #e0e0e0 50%,
    #f0f0f0 75%
  );
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
}

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配合 Transform 使用

Transform 属性

/* 位移 */
transform: translateX(100px);
transform: translateY(50px);
transform: translate(100px, 50px);

/* 旋转 */
transform: rotate(45deg);
transform: rotateX(45deg); /* 3D */
transform: rotateY(45deg); /* 3D */

/* 缩放 */
transform: scale(1.5);
transform: scaleX(2);

/* 倾斜 */
transform: skew(10deg);

/* 组合 */
transform: translateX(100px) rotate(45deg) scale(1.2);

3D 效果

/* 在父元素设置透视 */
.perspective-container {
  perspective: 1000px;
}

/* 卡片翻转 */
.card-3d {
  transform-style: preserve-3d;
  transition: transform 0.6s;
}

.card-3d:hover {
  transform: rotateY(180deg);
}

.card-front, .card-back {
  backface-visibility: hidden;
}

.card-back {
  transform: rotateY(180deg);
}

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性能优化

GPU 加速属性

/* ✅ GPU 加速（性能好） */
transform: translateX(100px);
transform: scale(1.1);
transform: rotate(45deg);
opacity: 0.5;

/* ❌ CPU 计算（触发重排） */
left: 100px;
width: 200px;
height: 200px;
margin: 10px;

will-change

/* 为动画目标提供提示 */
.animated {
  will-change: transform, opacity;
}

/* 仅在悬停时 */
.card:hover {
  will-change: transform;
}

/* 建议在动画后移除 */

避免重排

/* ❌ 应避免的模式 */
.bad {
  animation: move 1s infinite;
}
@keyframes move {
  to { left: 100px; } /* 触发重排 */
}

/* ✅ 推荐模式 */
.good {
  animation: moveGood 1s infinite;
}
@keyframes moveGood {
  to { transform: translateX(100px); } /* GPU 加速 */
}

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无障碍访问

尊重用户的动效偏好

/* 当用户偏好减少动效时 */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* 或选择性处理 */
@media (prefers-reduced-motion: reduce) {
  .animated {
    animation: none;
  }

  .transition {
    transition: none;
  }
}

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实用 UI 模式

按钮悬停

.button {
  background: #3b82f6;
  color: white;
  padding: 12px 24px;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.2s ease;
}

.button:hover {
  background: #2563eb;
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(59,130,246,0.4);
}

.button:active {
  transform: translateY(0);
}

下拉菜单

.dropdown {
  opacity: 0;
  visibility: hidden;
  transform: translateY(-10px);
  transition: all 0.2s ease;
}

.menu:hover .dropdown {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

模态框打开

.modal-overlay {
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s ease;
}

.modal-overlay.active {
  opacity: 1;
  visibility: visible;
}

.modal {
  transform: scale(0.9) translateY(20px);
  transition: transform 0.3s ease;
}

.modal-overlay.active .modal {
  transform: scale(1) translateY(0);
}

依次出现

.item {
  opacity: 0;
  transform: translateY(20px);
  animation: fadeInUp 0.5s ease forwards;
}

.item:nth-child(1) { animation-delay: 0.1s; }
.item:nth-child(2) { animation-delay: 0.2s; }
.item:nth-child(3) { animation-delay: 0.3s; }

@keyframes fadeInUp {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

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常见问题

Q1: transition 不起作用

A: 检查以下几点：

• 属性是否可动画
• 从 display: none 过渡时不起作用
• 是否明确定义了起始值和结束值

Q2: 如何保持动画结束后的状态？

A: 使用 animation-fill-mode: forwards

.element {
  animation: fadeIn 1s ease forwards;
}

Q3: 性能不好

A:

• 只对 transform 和 opacity 做动画
• 适当使用 will-change
• 避免对太多元素做动画

Q4: CSS 动画还是 JavaScript 动画？

A:

• 简单过渡: CSS
• 复杂序列: JavaScript（如 GSAP）
• 响应用户输入: JavaScript
• 自动循环: CSS

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总结

CSS 动画要点：

1. Transition: 响应状态变化
2. Animation: 自动播放，关键帧
3. Transform: GPU 加速，性能优异
4. 时间函数: ease, cubic-bezier
5. 无障碍: 尊重 prefers-reduced-motion

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