HTML5是一个全新的网页开发技术，可以帮助开发者更好地设计和制作网站。HTML5提供了很多强大的特性，包括新的标签、属性和API，可以让网站更加互动、响应式和富有创意性。而其中最有趣的特性就是HTML5背景代码。

HTML5背景代码可以让开发者设计独特的背景效果，让网站更加吸引人。在这里，我们提供了一些HTML5背景代码大全，供大家参考和使用。

/* 1. 纯色背景 */body {background-color: #92a8d1;}/* 2. 渐变背景 */body {background: linear-gradient(to bottom, #92a8d1 0%, #034f84 100%);}/* 3. 带图背景 */body {background-image: url("img/bg.jpg");background-repeat: no-repeat;background-size: cover;}/* 4. 动态渐变背景 */body {background: linear-gradient(to bottom, #fa709a 0%, #fee140 50%, #74ebd5 100%);animation: gradient 15s ease infinite;}@keyframes gradient {0% {background-position: 0% 50%;}50% {background-position: 100% 50%;}100% {background-position: 0% 50%;}}/* 5. 背景视频 */body {background: url("img/bg-video.jpg");background-size: cover;}#video-background {position: fixed;right: 0;bottom: 0;min-width: 100%;min-height: 100%;z-index: -100;}#video-background video {min-width: 100%;min-height: 100%;width: auto;height: auto;object-fit: cover;opacity: 0.7;}/* 6. 线条动画背景 */body {background-color: #141e30;}#background-animation {width: 100%;height: 100%;z-index: -1;position: fixed;top: 0;left: 0;}#background-animation .bg-line {position: absolute;width: 100%;height: 2px;background-color: #1f7a8c;top: 50%;animation: move 5s linear infinite;}#background-animation .bg-line:nth-child(2) {animation-delay: 0.2s;}#background-animation .bg-line:nth-child(3) {animation-delay: 0.4s;}#background-animation .bg-line:nth-child(4) {animation-delay: 0.6s;}#background-animation .bg-line:nth-child(5) {animation-delay: 0.8s;}@keyframes move {0% {transform: translateX(-100%);}100% {transform: translateX(100%);}}