corner button disappears on scrollable pages

Button is placed in the very bottom left corner and when i go to a page on my site that has a table of contents (on the left hand side) the button visually disappears but still functions. The button pretty much just changes the color of some of the text in my site.

as you can see the icon is not showing, my table of contents is long and enables scrolling on the left side of the page.

here is some of my code:

HTML:

    <button class="bottom-left-btn star-button"><i class="far fa-star"></i></button>

CSS:

.bottom-left-btn {
  bottom: 5px;
  left: 5px;
  background-color: transparent;
  color: var(--clr-text);
  font-size: 16px;
  border: none;
  cursor: pointer;
  z-index: 10000;
  display: block;
  position: fixed;
}

.toc {
  padding-left: 10%;
  z-index: 1; /* Ensure TOC has a lower z-index */
  position: relative; /* Ensure positioning context */
  ul {
    margin-bottom: 0; /* Remove bottom margin from nested sublists */
  }
}

JS:

document.addEventListener("DOMContentLoaded", function () {
    const starButtons = document.querySelectorAll('button.star-button');

    // Initialize jscolor picker
    let picker = null;

    jscolor.presets.default = {
        width: 200,
        position: 'right',
        backgroundColor: '#333',
        controlBorderColor: '#FFF',
        shadow: true,
        borderRadius: 6,
        borderWidth: 1,
        borderColor: '#444',
        previewElement: null,
        palette: [
            '#7092be', '#4040bf', '#ab548a', '#bf404c', '#b5a940', '#3fa687'
        ],
    };

    // Get the saved color from localStorage or set a default lightness
    const savedColor = localStorage.getItem('selectedColor');
    const cssHsl = getCssHsl('--clr-a-text');
    const initialHsl = savedColor ? JSON.parse(savedColor) : { ...cssHsl, l: 50 }; // Default lightness to 50%
    const hexColor = savedColor ? hslToHex(initialHsl.h, initialHsl.s, initialHsl.l) : hslToHex(cssHsl.h, cssHsl.s, 50); // Use CSS hue and saturation, default lightness to 50%

    function showColorPicker(e) {
        e.preventDefault();
        e.stopPropagation();
        const target = e.currentTarget.querySelector('i');

        if (!picker) {
            picker = new jscolor(target, {
                onInput: 'updateColor(this)',
                valueElement: null, // This ensures that the color value is not applied to the button itself
                previewElement: null, // No preview element
                value: hexColor // Set the initial color
            });
        }

        if (picker) picker.show();
    }

    if (starButtons.length > 0) {
        starButtons.forEach(button => {
            button.addEventListener('click', showColorPicker);
            button.addEventListener('touchstart', showColorPicker); // Add touchstart event listener for mobile
            const greenPart = button.querySelector('.green-part');
            if (greenPart) {
                greenPart.addEventListener('click', handleGreenPartClick);
                greenPart.addEventListener('touchstart', handleGreenPartClick); // Add touchstart event listener for mobile
            }
            console.log('Star button event listener added');
        });
    } else {
        console.log('No star buttons found');
    }

    function handleGreenPartClick(e) {
        e.preventDefault();
        e.stopPropagation();
        alert('Green part clicked!');
    }

    // Apply the saved color on page load
    if (savedColor) {
        const hslColor = JSON.parse(savedColor);
        applyColor(hslColor);
        console.log('Applied saved color:', hslColor);
    }
});

function updateColor(picker) {
    const hexColor = picker.toHEXString();
    const hslColor = hexToHSL(hexColor);

    console.log('New color selected: ', hslColor);

    applyColor(hslColor);
    // Save the selected color to localStorage
    localStorage.setItem('selectedColor', JSON.stringify(hslColor));
}

function applyColor(hslColor) {
    document.documentElement.style.setProperty('--clr-a-text', `hsl(${hslColor.h}, ${hslColor.s}%, var(--L-a-text))`);
    document.documentElement.style.setProperty('--clr-a-text-hvr', `hsl(${hslColor.h}, ${hslColor.s}%, calc(var(--L-a-text) * var(--L-a-text-hover-change)))`);
}

function hexToHSL(hex) {
 
}

function hslToHex(h, s, l) {
 
}

function getCssHsl(variable) {
    const style = getComputedStyle(document.documentElement);
    const value = style.getPropertyValue(variable);
    const hsl = value.match(/\d+/g).map(Number);
    return { h: hsl[0], s: hsl[1], l: hsl[2] };
}

Solution

You should move the .star-button out of the .sidebar, to be the direct child of .wrapper, because the .sidebar's overflow is cutting its visibility, like so:

<div class="wrapper">
  <button class="bottom-left-btn star-button"><i class="far fa-star jscolor" data-current-color="#4040BF"></i></button>
  <div class="sidebar">
    <!--rest of the code-->
  </div>
  <!--rest of the code-->
</div>

And then change to CSS for mobile under @media print, screen and (max-width: 960px) {, like so:

    .link-wrapper, .wrapper > .star-button {
        display: none !important;
    }