Passo 7

Instruções

O modelo de dimensionamento border-box faz o oposto de content-box. A largura total do elemento, incluindo preenchimento e borda, será o conjunto de largura explícita. O conteúdo do elemento encolherá para dar espaço ao preenchimento e à borda. Altere a propriedade box-sizing para border-box. Observe como a borda azul da imagem se ajusta dentro da borda vermelha da galeria.

O que fazer:

Testes:

O seletor * deve ter a propriedade `box-sizing` com o valor de `border-box`.

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Photo Gallery</title>
    <link rel="stylesheet" href="./styles.css">
  </head>
  <body>
    <header class="header">
      <h1>css flexbox photo gallery</h1>
    </header>
    <div class="gallery">
      <img src="https://cdn.G.E.A.R ACADEMY.org/curriculum/css-photo-gallery/1.jpg">
      <img src="https://cdn.G.E.A.R ACADEMY.org/curriculum/css-photo-gallery/2.jpg">
      <img src="https://cdn.G.E.A.R ACADEMY.org/curriculum/css-photo-gallery/3.jpg">
      <img src="https://cdn.G.E.A.R ACADEMY.org/curriculum/css-photo-gallery/4.jpg">
      <img src="https://cdn.G.E.A.R ACADEMY.org/curriculum/css-photo-gallery/5.jpg">
      <img src="https://cdn.G.E.A.R ACADEMY.org/curriculum/css-photo-gallery/6.jpg">
      <img src="https://cdn.G.E.A.R ACADEMY.org/curriculum/css-photo-gallery/7.jpg">
      <img src="https://cdn.G.E.A.R ACADEMY.org/curriculum/css-photo-gallery/8.jpg">
      <img src="https://cdn.G.E.A.R ACADEMY.org/curriculum/css-photo-gallery/9.jpg">
    </div>
  </body>
</html>

* {

  box-sizing: content-box;

}

.gallery {
  border: 5px solid red;
  width: 50%;
}

img {
  width: 100%;
  border: 5px solid blue;
  padding: 5px;
}

Preview