timer.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Countdown Timer</title>
    <!-- Link to External CSS -->
    <link rel="stylesheet" href="timer.css">
</head>
<body>
    <div class="container">
        <h1>Countdown Timer</h1>
        
        <!-- Input Section -->
        <div class="input-section">
            <label for="date-input">Select Target Date and Time:</label>
            <input type="datetime-local" id="date-input">
            <button id="start-button">Start Countdown</button>
        </div>
        
        <!-- Countdown Display -->
        <div class="countdown">
            <div class="time-segment">
                <span id="days">00</span>
                <span>Days</span>
            </div>
            <div class="time-segment">
                <span id="hours">00</span>
                <span>Hours</span>
            </div>
            <div class="time-segment">
                <span id="minutes">00</span>
                <span>Minutes</span>
            </div>
            <div class="time-segment">
                <span id="seconds">00</span>
                <span>Seconds</span>
            </div>
        </div>
    </div>
    
    <!-- Link to External JavaScript -->
    <script src="timer.js"></script>
</body>
</html>