ui/src/widgets/resize_handle.scss

// Copyright (C) 2025 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

// Hitbox: 5px total clickable area (via ::before extending beyond visible area)
// Accent: 3px visible hover area
// Border: 1px visible line when not hovering
$hitbox: 2px; // Extra clickable area on each side
$accent: 1px;
$thickness: 1px;

.pf-resize-handle {
  z-index: 10;
  touch-action: none;
  position: relative;
  background-color: var(--pf-color-border);
  flex-shrink: 0;

  &::before {
    content: "";
    position: absolute;
  }

  &:hover {
    &::after {
      content: "";
      position: absolute;
      background: var(--pf-color-accent);
    }
  }

  // Vertical variant (horizontal bar for top/bottom dragging)
  &--vertical {
    cursor: row-resize;
    width: 100%;
    height: $thickness;

    &::before {
      inset: (-$hitbox) 0;
    }

    &::after {
      inset: (-$accent) 0;
    }
  }

  // Horizontal variant (vertical bar for left/right dragging)
  &--horizontal {
    cursor: col-resize;
    width: $thickness;
    height: 100%;

    &::before {
      inset: 0 (-$hitbox);
    }

    &::after {
      inset: 0 (-$accent);
    }
  }
}