* {
  padding: 0;
  margin: 0;
  color-scheme: dark;
}


body, ul{
  padding: 15px;
}
ul li {
  padding:5px;
}

div {
  box-sizing: content-box;
  width:100px;
  height: 100px;
  background: red;
  padding:10px;
  margin: 20px 0;
}
div p {
  border: 2px solid;
}

div:nth-child(2) {
  /*
  tamanho da caixa: ate a borda da caixa
  */
  box-sizing: border-box;
 background: green;

}

section {
  height: auto;
  margin-top: 15px;
}

section.box{
  border: 1px solid blue;  
  width: 100px;
  margin: auto;
}

section.check {
  text-align: center;
  margin-bottom: 20px;
}

p{
  margin: 10px 0;
}
 
h1{
  text-align: center;
  padding-bottom: 30px;
}

span {
  font-weight: bold;
}

main{
  max-width: 800px;
  margin: auto;
  position: relative;
  min-height: 90vh;
}

footer{
  position: absolute;
  bottom: 0;
  min-height: 30px;
  text-align: center;
  width: 100%;
}