border-left CSSプロパティで左側の境界線のスタイルを指定する
CSS | border-left-width Property - GeeksforGeeks
CSS/Properties/border-left-color - W3C Wiki
CSS Border | o7planning.org
ボックスモデルを極めるためのCSSプロパティ、10選：D89 CSS/スタイルシート リファレンス辞典（4） - ＠IT
CSS Border-Left Property
CSS Border Left | Learn the Working of CSS Border Left with Examples
Box rendering type
css - Left half-rounded border - Stack Overflow
border-left-style | Codrops
CSS How to: border-left - YouTube
CSS border-left Property
border-top-left-radius - CSS: Cascading Style Sheets | MDN
css - how to create top left and bottom right border with different color? - Stack Overflow
html - how to give input border left and right small length - Stack Overflow
CSS Border-Left Property
CSS border-left-style Property
CSS Border — TutorialBrain
Border sides in CSS
css - How to make border-left above border-bottom? - Stack Overflow
CSS | border-left Property - GeeksforGeeks
CSS Border-Left Property
CSS border-left Property
