Start using Rewards button in Brave Rewards NTP widget isn't clickable

[stephendonner]

Description

Start using Rewards button in Brave Rewards NTP widget isn't clickable

Steps to Reproduce

1. new profile
2. launch Brave
3. load a new-tab page
4. try to click on the Start using Rewards button on the widget

Actual result:

The Start using Rewards button isn't clickable, most times.

Expected result:

The Start using Rewards button should be clickable and enable Rewards.

Reproduces how often:

100%

Brave version (brave://version info)

Brave	1.30.33 Chromium: 93.0.4577.42 (Official Build) nightly (x86_64)
Revision	f794baa90de7ca837ab1f8dc0c482a20140ba26a-refs/branch-heads/4577@{#744}
OS	macOS Version 11.5.2 (Build 20G95)

Version/Channel Information:

• Can you reproduce this issue with the current release? no
• Can you reproduce this issue with the beta channel? no
• Can you reproduce this issue with the nightly channel? yes

/cc @zenparsing @petemill @emerick

[stephendonner]

Meant to mention: this works using 1.30.31.

[zenparsing]

It appears that the main Rewards widget content and the notification container are assigned to the same CSS grid, with the notification container occurring later in the layout. It may be that CSS grid behavior has changed slightly such that a later element overrides a prior element when the grid layout is computed.

[stephendonner]

Verified PASSED using

Brave	1.29.74 Chromium: 93.0.4577.58 (Official Build) (x86_64)
Revision	c4410ece044414ea42fa4ba328d08195e818a99c-refs/branch-heads/4577@{#1076}
OS	macOS Version 11.5.2 (Build 20G95)

Steps:

1. new profile
2. launched Brave
3. loaded a new-tab page
4. clicked on the Start using Rewards button on the widget
5. confirmed that Brave Rewards was enabled

example	example

[stephendonner]

Also verified on

Brave	1.29.74 Chromium: 93.0.4577.58 (Official Build) (64-bit)
Revision	c4410ece044414ea42fa4ba328d08195e818a99c-refs/branch-heads/4577@{#1076}
OS	Linux

example	example