def render_sequence(sequence, pam_sites):

    html = """
    <div style='
        font-family: monospace;
        font-size: 14px;
        line-height: 1.8;
        word-wrap: break-word;
        background-color: #111827;
        color: #e5e7eb;
        padding: 20px;
        border-radius: 12px;
        overflow-x: auto;
    '>
    """

    guide_positions = {}
    pam_positions = {}
    cut_positions = set()

    for idx, site in enumerate(pam_sites):

        start = site["position"]
        guide_len = len(site["guide"])

        for i in range(start, start + guide_len):
            guide_positions[i] = idx

        pam_start = start + guide_len

        for i in range(pam_start, pam_start + 3):
            pam_positions[i] = idx

        cut_positions.add(site["cut_site"])

    for i, base in enumerate(sequence):

        style = ""

        if i in guide_positions:
            style += "background-color:#2563eb;color:white;"

        if i in pam_positions:
            style += "background-color:#dc2626;color:white;font-weight:bold;"

        if i in cut_positions:
            style += "border-bottom:3px solid #22c55e;"

        if i % 10 == 0:
            html += f"<span style='color:#9ca3af;'> {i} </span>"

        html += f"<span style='{style}'>{base}</span>"

        if (i + 1) % 80 == 0:
            html += "<br><br>"

    html += """

    <br><br>

    <div style='margin-top:20px;'>

        <div>
            <span style='background:#2563eb;color:white;padding:4px;border-radius:4px;'>
            Guide RNA
            </span>
        </div>

        <br>

        <div>
            <span style='background:#dc2626;color:white;padding:4px;border-radius:4px;'>
            PAM Site (NGG)
            </span>
        </div>

        <br>

        <div>
            <span style='border-bottom:3px solid #22c55e;padding:2px;'>
            Cas9 Cut Site
            </span>
        </div>

    </div>

    </div>
    """

    return html