CSS 滿版區塊 (Full Screen Section)

滿版區塊是指佔據整個視窗高度的區塊，常用於首頁 Hero 區域、Landing Page 的各個區段。

基本滿版

.fullscreen {
  height: 100vh;
}

100vh 表示視窗高度的 100%。

滿版 + 置中內容

.hero {
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  text-align: center;
}

完整範例

Hero 區塊

.hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: 24px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 4rem);
  margin: 0 0 16px;
}

.hero p {
  font-size: clamp(1rem, 2vw, 1.25rem);
  max-width: 600px;
  margin: 0 0 32px;
  opacity: 0.9;
}

.hero-buttons {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  justify-content: center;
}

背景圖片 Hero

.hero {
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
  color: white;
}

.hero-background {
  position: absolute;
  inset: 0;
  z-index: -1;
}

.hero-background img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* 暗化覆蓋層 */
.hero-background::after {
  content: '';
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
}

.hero-content {
  text-align: center;
  padding: 24px;
  max-width: 800px;
}

影片背景

.hero {
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
  overflow: hidden;
}

.hero-video {
  position: absolute;
  inset: 0;
  z-index: -1;
}

.hero-video video {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hero-video::after {
  content: '';
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.4);
}

<section class="hero">
  <div class="hero-video">
    <video autoplay muted loop playsinline>
      <source src="video.mp4" type="video/mp4">
    </video>
  </div>
  <div class="hero-content">
    <h1>標題</h1>
  </div>
</section>

分割畫面

.split-screen {
  min-height: 100vh;
  display: flex;
}

.split-left {
  flex: 1;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 60px;
  background: #f5f5f5;
}

.split-right {
  flex: 1;
  background: url('image.jpg') center/cover;
}

@media (max-width: 768px) {
  .split-screen {
    flex-direction: column;
  }
  
  .split-left,
  .split-right {
    min-height: 50vh;
  }
}

多個滿版區段

.section {
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 60px 24px;
}

.section:nth-child(odd) {
  background: white;
}

.section:nth-child(even) {
  background: #f5f5f5;
}

.section-content {
  max-width: 1200px;
  width: 100%;
}

捲動指示

告訴使用者可以往下捲動：

.scroll-indicator {
  position: absolute;
  bottom: 40px;
  left: 50%;
  transform: translateX(-50%);
  animation: bounce 2s infinite;
}

@keyframes bounce {
  0%, 100% {
    transform: translateX(-50%) translateY(0);
  }
  50% {
    transform: translateX(-50%) translateY(10px);
  }
}

考量固定元素

如果有固定導航列，需要調整高度：

.hero {
  min-height: calc(100vh - 60px);  /* 扣除導航高度 */
  margin-top: 60px;                /* 或用 padding-top */
}

行動裝置注意事項

在行動裝置上，100vh 可能會因為瀏覽器的網址列而有問題。可以使用：

.hero {
  min-height: 100vh;
  min-height: 100dvh;    /* dynamic viewport height */
}

或使用 JavaScript 計算：

function setVH() {
  let vh = window.innerHeight * 0.01;
  document.documentElement.style.setProperty('--vh', `${vh}px`);
}

setVH();
window.addEventListener('resize', setVH);

.hero {
  min-height: 100vh;
  min-height: calc(var(--vh, 1vh) * 100);
}

最小高度 vs 固定高度

建議使用 min-height 而不是 height，這樣當內容超出時不會被裁切：

/* 推薦 */
.section {
  min-height: 100vh;
}

/* 不推薦 */
.section {
  height: 100vh;
  overflow: hidden;
}