Lightning component modal window with fixed size and proper closing buttons

I want to use a salesforce modal window using a lightning component, fixing its size to 90% width AND height of the screen to display larger content (a pdf preview). The standard modal component seems to provide only limited support for resizing.

Any help to properly use a modal screen element is highliy appreciated!

Details

Standard modal example

I created a lightning component *.cmp which is opened via a QuickAction Button in a Salesforce modal window on top of a record page of a custom object.

Using the the standard example for a large-modal I get a window only using the center 1/3 of the screen.

Extra css for 90% width

Using some extra css ...

<aura:html tag="style">
    .slds-modal__container {
        min-width: 90vw;  /* Stretch to 90% of viewing width (vw) */
    }
</aura:html>

...I can stretch the width of the window, but it will not render the window properly anymore

• misplaced closing x
• doubled closing x
• underlying white div

Aim and reference of managed package

My aim is to have

• blurring in background fill full screen (actually there is already a darker blurring, overlayed by the even darker, partial blurring?)
• Modal window cover 90% width AND height
• Proper closing x available

I saw such a proper behaviour on a managed package, but I cannot reproduce it. I also want to use a PDF preview, which is why I need the 90% height / width. See image below

Current status

With my code below I manage to get close to it but still with

• strange double-blurring, not 100% filling screen
• Misplaces / double X-close buttons
• only using fixed px-height for pdf viewing element, i.e. not responsive

Code reference for lightning component

Note: onclick actions not used here

<aura:component implements="force:lightningQuickActionWithoutHeader,force:hasRecordId">
    <aura:attribute name="recordId" type="String"/>
    
    <aura:html tag="style">
        .slds-modal__container {
            min-width: 90vw;    
        }
    </aura:html>
      
    <section role="dialog" tabindex="-1" class="slds-modal slds-fade-in-open slds-modal_large" aria-labelledby="modal-heading-01" aria-modal="true">
        <div class="slds-modal__container">
            <div class="slds-modal__header">
                <h1 id="modal-heading-01" class="slds-modal__title slds-hyphenate">Test 007</h1>
                <lightning:buttonIcon
                    iconName="utility:close"
                    onclick=""
                    alternativeText="close"
                    variant="bare-inverse"
                    class="slds-modal__close"/>
            </div>
            <div id="modal-content-id-1" class="slds-modal__content slds-p-around_medium">
                <iframe
                        src="{! 'https://<url-to-my-sf-org.com>/apex/<my-apex-class-for-pdf-rending>?Id='+v.recordId}"
                        width="100%"
                        height="600px"/>
            </div>
            <div class="slds-modal__footer">
                <button
                        class="slds-button slds-button_brand"
                        aria-label="Create and attach"
                        onclick="}">
                    Create</button>                
                <button
                        class="slds-button slds-button_neutral"
                        aria-label="Cancel"
                        onclick="">
                    Cancel</button>
            </div>
        </div>
    </section>
    <div class="slds-backdrop slds-backdrop_open" role="presentation"></div>  

</aura:component>

Any idea how to achieve the desired behaviour?