Remove drop shadows from brave://rewards/

[jonathansampson]

Description

A user on Twitter recently shared the Settings page cards lack drop shadows seen on the Rewards page, even though the two pages share many other style elements.

Steps to Reproduce

Navigate to about:rewards
Navigate to about:settings

Actual result:

Drop shadows present on Rewards page, but not Settings page.

Expected result:

Drop shadows removed from Rewards page.

Reproduces how often:

Always

Brave version (brave://version info)

1.7.98

[karenkliu]

The issue here is not to add drop shadows to the Settings page; it's to remove drop shadows from the Brave Rewards page.

The design team has standardized our drop shadow treatment so that only UI elements sitting on top of the page, such as menus and modals, will get the drop shadows. In this case the cards on the Brave Rewards page is "Layer 0 Content" so they do not get a drop shadow.

Drop shadows per UI layer defined:

[LaurenWags]

Verified passed with

Brave | 1.17.28 Chromium: 86.0.4240.75 (Official Build) nightly (x86_64)
-- | --
Revision | c69c33933bfc72a159aceb4aeca939eb0087416c-refs/branch-heads/4240@{#1149}
OS | macOS Version 10.14.6 (Build 18G3020)

Confirmed no shadows on brave://rewards page with 1.17.x

1.16.x shadows exist

1.17.x no shadows

---

Verification passed on

Brave	1.17.28 Chromium: 86.0.4240.75 (Official Build) nightly (64-bit)
Revision	c69c33933bfc72a159aceb4aeca939eb0087416c-refs/branch-heads/4240@{#1149}
OS	Ubuntu 18.04 LTS

Confirmed no shadows on brave://rewards page with 1.17.x

1.16.x shadows exist

1.17.x no shadows

---

Verification passed on

Brave | 1.17.42 Chromium: 86.0.4240.99 (Official Build) nightly (64-bit)
-- | --
Revision | 002668237e13d38aabd6d11c2d216dd22b736ff2-refs/branch-heads/4240@{#1229}
OS | Windows 10 OS Version 1903 (Build 18362.1082)

Confirmed no shadows on brave://rewards page with 1.17.x
1.16.x

1.17.x