timeline.html

<style>
    #timeline-container {
        position: fixed;
        bottom: 0;
        left: 0;
        right: 0;
        z-index: 100;
        background-color: rgba(0,0,0,.7);
    }

    #timeline-container.collapsed {
        bottom: -70px;
    }

    #timeline-toggle {
        background-color: rgba(0,0,0,.7);
        border-top-left-radius: 10px;
        border-top-right-radius: 10px;
        cursor: pointer;
        padding: 3px 20px;
        position: absolute;
        top: -26px;
        transform: translateX(-50%);
        left: 50%;
        color: #ffffff;
        font-weight: bold;
    }

    .slider-step:hover::after {
        content: attr(data-date);
        position: absolute;
        bottom: 100%;
        left: 50%;
        transform: translateX(-50%);
        background-color: #333;
        color: #fff;
        padding: 5px;
        border-radius: 3px;
        white-space: nowrap;
        font-size: 12px;
    }

    #timeline {
        display: flex;
        align-items: center;
        overflow-x: auto;
        height: 50px;
        padding: 10px 10px 10px 30px;
        color: #fff;
    }

    .slider-container {
        position: relative;
        height: 100%;
        padding: 0 10px;
    }

    .slider-step {
        position: absolute;
        top: 50%;
        margin-top: 1px;
        transform: translateY(-50%);
        width: 15px;
        height: 15px;
        border-radius: 50%;
        background-color: #fff;
        cursor: pointer;
    }

    .slider-step[data-gpt-version]::before {
        content: attr(data-gpt-version);
        position: absolute;
        top: 100%;
        left: 50%;
        transform: translateX(-50%);
        background-color: #333;
        color: #fff;
        padding: 2px 4px;
        border-radius: 3px;
        white-space: nowrap;
        font-size: 12px;
    }

    .slider-track {
        position: absolute;
        top: 50%;
        width: 90vw;
        height: 2px;
        background-color: #fff;
    }

    .slider-thumb {
        position: absolute;
        top: 50%;
        transform: translateY(-50%);
        width: 20px;
        height: 20px;
        border-radius: 50%;
        background-color: #007bff;
        cursor: pointer;
        z-index: 5;
    }

    #slider {
        position: relative;
    }
</style>
<div id="timeline-container" class="collapsed">
    <div id="timeline-toggle" title="Toggle timeline feature">∧</div>
    <div id="timeline">
        <div id="slider">
            <div class="slider-track"></div>
            <div class="slider-thumb"></div>
        </div>
    </div>
</div>