<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Analog Clock - Correct Centering</title>
    <style>
        body {
            display: flex;
            justify-content: center;
            align-items: center;
            height: 100vh;
            background-color: #ffffff;
            margin: 0;
        }
        .clock {
            width: 300px;
            height: 300px;
            border: 10px solid #333;
            border-radius: 50%;
            position: relative;
            background-color: white;
            box-shadow: 5px 5px 15px rgba(0,0,0,0.2);
        }
        .number {
            position: absolute;
            font-size: 24px;
            font-weight: bold;
            color: #333;
            text-align: center;
            /* ODEBRÁNO: width: 100%; - to způsobovalo roztahování */
            width: 30px; /* Fixed width matching font size roughly */
            height: 30px;
            line-height: 30px; /* Vertically centers text if only one line */
            /* Margin auto zajišťuje centrování v rámci dané pozice */
            margin-left: -15px; /* Posune o polovinu šířky doleva (30/2) */
            margin-top: -15px;  /* Posune o polovinu výšky nahoru (30/2) */
        }
        .hand {
            position: absolute;
            bottom: 50%;
            left: 50%;
            transform-origin: bottom center;
            transform: translateX(-50%);
            border-top-left-radius: 5px;
            border-top-right-radius: 5px;
            z-index: 10;
        }
        .hour {
            width: 8px;
            height: 70px;
            background-color: #333;
        }
        .minute {
            width: 6px;
            height: 100px;
            background-color: #666;
        }
        .second {
            width: 3px;
            height: 120px;
            background-color: #d32f2f;
            z-index: 11;
        }
        .center {
            position: absolute;
            width: 15px;
            height: 15px;
            background-color: #333;
            border-radius: 50%;
            top: 50%;
            left: 50%;
            transform: translate(-50%, -50%);
            z-index: 12;
        }
        .hour-mark {
            position: absolute;
            width: 2px;
            height: 15px;
            background-color: #333;
            left: 50%;
            top: 0;
            transform-origin: center 150px;
        }
    </style>
</head>
<body>
    <div class="clock" id="clock">
        <div class="center"></div>
        <div class="hand hour" id="hourHand"></div>
        <div class="hand minute" id="minuteHand"></div>
        <div class="hand second" id="secondHand"></div>
    </div>

    <script>
        const clock = document.getElementById('clock');
        const hourHand = document.getElementById('hourHand');
        const minuteHand = document.getElementById('minuteHand');
        const secondHand = document.getElementById('secondHand');

        // Add clock numbers - using math to position, but NOT rotating the text
        for (let i = 1; i <= 12; i++) {
            const number = document.createElement('div');
            number.className = 'number';
            number.textContent = i;
            const angle = i * 30; // 30 degrees per hour

            // Math: x = cx + r * cos(θ), y = cy + r * sin(θ)
            // In CSS, 0° is at 3 o'clock, but clock numbers start at 12 o'clock (which is -90° or 270°).
            // cos(θ - 90°) = sin(θ), sin(θ - 90°) = -cos(θ)
            const radius = 120; // Distance from center to numbers
            const cx = 150; // Center X (half of clock width)
            const cy = 150; // Center Y (half of clock height)

            // Vzorec pro polohu čísla:
            // (angle - 90) nám dává správný úhel od 12 hodin
            const x = cx + radius * Math.cos((angle - 90) * Math.PI / 180);
            const y = cy + radius * Math.sin((angle - 90) * Math.PI / 180);

            // Přesné umístění s margin-left/margin-top pro vodorovné a svislé centrování
            number.style.left = x + 'px';
            number.style.top = y + 'px';

            clock.appendChild(number);
        }

        // Add hour marks (tradiční způsob)
        for (let i = 0; i < 12; i++) {
            const mark = document.createElement('div');
            mark.className = 'hour-mark';
            mark.style.left = '50%';
            mark.style.top = '0';
            mark.style.transform = `rotate(${i * 30}deg)`;
            mark.style.transformOrigin = 'center 150px';
            clock.appendChild(mark);
        }

        function updateTime() {
            const now = new Date();
            const seconds = now.getSeconds();
            const minutes = now.getMinutes();
            const hours = now.getHours();

            const secondDegrees = (seconds / 60) * 360;
            const minuteDegrees = ((minutes + seconds / 60) / 60) * 360;
            const hourDegrees = ((hours % 12 + minutes / 60) / 12) * 360;

            // translateX(-50%) je důležité pro centrování šířky ručičky
            secondHand.style.transform = `translateX(-50%) rotate(${secondDegrees}deg)`;
            minuteHand.style.transform = `translateX(-50%) rotate(${minuteDegrees}deg)`;
            hourHand.style.transform = `translateX(-50%) rotate(${hourDegrees}deg)`;
        }

        setInterval(updateTime, 1000);
        updateTime();
    </script>
</body>
</html>