odoo_theme/theme_clean/views/assets.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>
    <template id="_assets_primary_variables" inherit_id="website._assets_primary_variables" priority="1">
        <xpath expr="//link[last()]" position="after">
            <link rel="stylesheet" type="text/scss" href="/theme_clean/static/src/scss/primary_variables.scss"/>
        </xpath>
    </template>
    <template id="_assets_frontend_helpers" inherit_id="website._assets_frontend_helpers" priority="1">
        <xpath expr="//link" position="before">
            <link rel="stylesheet" type="text/scss" href="/theme_clean/static/src/scss/bootstrap_overridden.scss"/>
        </xpath>
    </template>

    <template id="assets_frontend" inherit_id="website.assets_frontend" priority="1">
        <xpath expr="//link[last()]" position="after">
            <link rel="stylesheet" type="text/scss" href="/theme_clean/static/src/scss/theme.scss"/>

            <link rel="stylesheet" type="text/scss" href="/theme_common/static/src/scss/s_discount.scss"/>
            <link rel="stylesheet" type="text/scss" href="/theme_common/static/src/scss/s_event_list.scss"/>
            <link rel="stylesheet" type="text/scss" href="/theme_common/static/src/scss/s_profile.scss"/>
            <link rel="stylesheet" type="text/scss" href="/theme_common/static/src/scss/s_icon_box.scss"/>
            <link rel="stylesheet" type="text/scss" href="/theme_common/static/src/scss/s_pricing.scss"/>
            <link rel="stylesheet" type="text/scss" href="/theme_common/static/src/scss/s_process_steps.scss"/>
            <link rel="stylesheet" type="text/scss" href="/theme_common/static/src/scss/s_timeline.scss"/>
            <link rel="stylesheet" type="text/scss" href="/theme_common/static/src/scss/s_color_blocks_2.scss"/>
            <link rel="stylesheet" type="text/scss" href="/theme_common/static/src/scss/s_color_blocks_4.scss"/>
            <link rel="stylesheet" type="text/scss" href="/theme_common/static/src/scss/s_big_image.scss"/>
            <link rel="stylesheet" type="text/scss" href="/theme_common/static/src/scss/s_big_image_parallax.scss"/>
            <link rel="stylesheet" type="text/scss" href="/theme_common/static/src/scss/s_team_profiles.scss"/>
            <link rel="stylesheet" type="text/scss" href="/theme_common/static/src/scss/s_text_highlight.scss"/>
            <link rel="stylesheet" type="text/scss" href="/theme_common/static/src/scss/s_two_columns.scss"/>
        </xpath>
    </template>

    <template id="assets_editor" inherit_id="website.assets_editor">
        <xpath expr="//script[last()]" position="after">
            <script type="text/javascript" src="/theme_common/static/src/js/s_progress_bar.js"></script>
        </xpath>
    </template>
</odoo>