# Sử dụng GSAP Timeline để animate show/hide search box khi click button (ok)

✅ **1. HTML**

```html
<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8" />
  <meta name="viewport" content="width=device-width, initial-scale=1.0" />
  <title>GSAP Timeline Show Search Box</title>
  <style>
    body {
      font-family: sans-serif;
      background: #f0f0f0;
      padding: 50px;
    }
    .search-btn {
      padding: 10px 20px;
      background: #007bff;
      color: white;
      border: none;
      cursor: pointer;
      border-radius: 4px;
    }
    .search-box {
      width: 300px;
      padding: 20px;
      background: white;
      border: 1px solid #ccc;
      margin-top: 20px;
      opacity: 0;
      transform: translateY(-20px);
      display: none; /* hidden by default */
    }
  </style>
</head>
<body>
  <button class="search-btn">Search</button>
  <div class="search-box">
    <input type="text" placeholder="Search..." style="width: 100%; padding: 10px;">
  </div>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/gsap/3.12.2/gsap.min.js"></script>
  <script>
    const btn = document.querySelector(".search-btn");
    const box = document.querySelector(".search-box");
    // Create timeline paused
    const tl = gsap.timeline({ paused: true, reversed: true });
    tl.to(box, {
      display: "block", // instantly set display block
      duration: 0,
    })
    .fromTo(box, 
      { 
       opacity: 0, 
       y: -20 
      }, 
      { 
       opacity: 1, 
       y: 0, 
       duration: 0.5, 
       ease: "power2.out" 
      }
    );
    btn.addEventListener("click", () => {
      if (tl.reversed()) {
        tl.play();
      } else {
        tl.reverse();
      }
    });
    // Optional: hide box completely after reverse animation ends
    tl.eventCallback("onReverseComplete", () => {
      box.style.display = "none";
    });
  </script>
</body>
</html>

```
