cellpadding

th, td {
    border: 1px solid black;
    padding: 5px;
}

table#myTable {
  border-collapse:collapse;
}

separate

collapse

.container {
    box-sizing: border-box;
}

* {
    margin: 0px;
    padding: 0px;
}

.container {
    width:1000px;
    margin:0px auto;
}

<header>

<footer>

<article>

<article>
    <header>
        <h2>some header</h2>
    </header>
    <p> some paragraph</p>
    <p> some other paragraph</p>
    <footer>
        written by Quentin Watt
    </footer>
</article>

<main>

<main>

<article>

<aside>

<footer>

<header>

<nav>

<footer>

<h1>

<h6>

<header>

<header>

<footer>

<address>

<header>