index.html

<!DOCTYPE html>
<html>
<head>
    <style>
        body {
            background-color: black;
            color: white;
            display: flex;
            flex-direction: column;
            justify-content: center;
            align-items: center;
            height: 100vh;
            font-family: Arial, sans-serif;
        }
        #clock {
            display: flex;
            flex-direction: row;
            justify-content: center;
            margin-bottom: 20px;
        }
        .bar {
            width: 10px;
            height: 100px;
            margin: 0 2px;
            transition: background 0.5s;
        }
        .hour { 
            background: darkgreen; 
        }
        .minute { 
            background: darkblue; 
            margin-left: 2px; /* Adjusted space between minute bars */
        }
        .second { 
            background: darkred; 
            margin-left: 2px; /* Adjusted space between second bars */
        }
        .on { opacity: 1; }
        .off { opacity: 0.3; }
        .group { 
            margin-left: 20px; /* Adjusted space between groups */
        }
    </style>
</head>
<body>
    <div id="clock"></div>
    <div style="margin-top: 20px;">
        <label><input type="checkbox" id="format" checked> 12 hour format</label>
    </div>
    <script>
        const clock = document.getElementById('clock');
        const format = document.getElementById('format');
        const bars = Array.from({length: 18}, (_, i) => {
            const bar = document.createElement('div');
            bar.className = 'bar ' + (i < 6 ? 'hour' : i < 12 ? 'minute' : 'second');
            if (i === 6 || i === 12) {
                bar.classList.add('group'); /* Add group class to first bar of each group */
            }
            clock.appendChild(bar);
            return bar;
        });
        setInterval(() => {
            const now = new Date();
            const hours = format.checked ? now.getHours() % 12 || 12 : now.getHours();
            const minutes = now.getMinutes();
            const seconds = now.getSeconds();
            const binary = [hours, minutes, seconds].map(n => n.toString(2).padStart(6, '0')).join('');
            bars.forEach((bar, i) => {
                bar.classList.remove('on', 'off');
                bar.classList.add(binary[i] === '1' ? 'on' : 'off');
            });
        }, 1000);
    </script>
</body>
</html>