bug(sort header): Default focus state do not work well with strong focus indicator

[ryuran]

Is this a regression?

• Yes, this behavior used to work in the previous version

The previous version in which this bug was not present was

No response

Description

Default sort header bottom border on focus conflicts with strong focus indicators, creating double borders that reduce clarity.

Reproduction

StackBlitz link: https://stackblitz.com/edit/components-issue-starter-yb5arsxr?file=src%2Fmain.ts
Steps to reproduce: naviagate using keyboard with Tab and Shift+Tab, when a table header is focus a bottom border appear + the strong focus-indicator

Expected Behavior

remove the default focus state border when strong focus-indicator is set.

[mat-sort-header].cdk-program-focused .mat-sort-header-container,
[mat-sort-header].cdk-keyboard-focused .mat-sort-header-container {
  border-bottom: none;
}

Actual Behavior

Default sort header bottom border on focus conflicts with strong focus indicators, creating double borders that reduce clarity.

Environment

• Angular: 19
• CDK/Material: 19
• Browsers: all
• Operating System (e.g. Windows, macOS, Ubuntu): all