<!DOCTYPE html>
<html>
<head>
    <title>Random Line Selector</title>
    <script>
        function startCountdown() {
            const countdownElement = document.getElementById("countdown");
            let countdownValue = 5; // Countdown from 5 seconds

            countdownElement.innerText = "Countdown: " + countdownValue;
            const interval = setInterval(() => {
                countdownValue--;
                countdownElement.innerText = "Countdown: " + countdownValue;

                if (countdownValue === 0) {
                    clearInterval(interval);
                    displayRandomLine();
                }
            }, 1000);
        }

        function displayRandomLine() {
            const lines = document.getElementById("multilineTextbox").value.split("\n");
            const randomIndex = Math.floor(Math.random() * lines.length);
            document.getElementById("selectedLine").innerText = "Selected Line: " + lines[randomIndex];
        }
    </script>
</head>
<body>
    <h1>Random Line Selector</h1>
    <textarea id="multilineTextbox" rows="10" cols="30" placeholder="Enter multiple lines here..."></textarea>
    <br><br>
    <button onclick="startCountdown()">Select Random Line</button>
    <p id="countdown"></p>
    <p id="selectedLine"></p>
</body>
</html>