:root {
  --font-size: 18px;
  --line-height: 1.5;
  --heading-font: 'Avenir', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
  --body-font: 'Iowan Old Style', Garamond, Georgia, serif;

  --heading-color: #000;
  --body-color: #3d3d3d;
}

* {
  box-sizing: border-box;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizelegibility;
}

html, body{
  width: 100%;
  height: 100%;

  margin: 0;
  padding: 0;
}

html {
  font-family: var(--body-font);
  font-size: var(--font-size);
  line-height: var(--line-height);
  color: var(--body-color);
}

img {
  max-width: 100%;
  display: block;
}
h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: var(--heading-font);
  color: var(--heading-color);
  font-weight: 700;
}

h1 { font-size: 2rem; }
h2 { font-size: 1.75rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }
h5 { font-size: 1rem; }
h6 { font-size: 0.8rem; }

p, li {
  margin: 1rem 0;
}

body {
    /* background-color: #f5f5f5; */

    display: flex;
    flex-direction: column;
    align-items: center;
}

header {
    width: 100%;
    height: 60px;

    position: fixed;
    top: 0;

    display: flex;
    justify-content: space-around;
    align-items: center;

    background-color: white;
}

header > nav {
    display: flex;
    gap: 20px;
}

header > nav > a {

    transition-duration: 0.5s;

    text-decoration: none;
    color: var(--heading-color);

    border-bottom: 2px solid transparent;
}

header > nav > a:hover {
    border-color: var(--heading-color);
}

header > nav > a > span {
    border-bottom: 2px solid black;
}
header > nav:last-child a:hover {
    border-color: transparent;
}

main{
    flex: 1;

    margin-top: 60px;
    
    width: 900px;
}

section {
    display: flex;
    flex-direction: column;
    justify-content: space-around;
    gap: 10px;
}

section > article {
    border: 1px solid lightgray;
    border-radius: 5px;

    padding: 10px;
    /* margin-bottom: 10px; */

    position: relative;

    display: flex;
    flex-direction: column;
    justify-content: space-around;
}

section > article:hover {
    background-color: whitesmoke;
}

section > article a {
    text-decoration: none;
    color: black;
    z-index: 1;
}

section > article a::after{
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    content: ' ';
}

section > article h3 {
    margin: 0px;
}

footer {
    margin-top: 40px;
    min-height: 60px;

    display: flex;
    justify-content: space-around;
    align-items: center;

    gap: 35px;
}

footer > img {
    height: 60px;
}

table {
    border:none;
    border-collapse: collapse;

    border-bottom: 1px solid lightgray;

    display: block;
    overflow-x: auto;
}

table th {
    border-top: 1px solid lightgray;
    border-bottom: 1px solid lightgray;
}

table td, th {
    padding: 10px;

    border-left: 1px solid lightgray;
    border-right: 1px solid lightgray;
}

/* table td:first-child {
    border-left: none;
}
table th:first-child {
    border-left: none;
}

table td:last-child {
    border-right: none;
}
table th:last-child {
    border-right: none;
} */


@media only screen and (max-width: 1300px) {
    header { 
        justify-content: space-between; 
        padding-left: 10px; 
        padding-right: 10px;
    }
}

@media only screen and (max-width: 950px) {
    main { 
        width: 100%;
        padding-left: 10px; 
        padding-right: 10px;
    }
}

@media only screen and (max-width: 560px) {
    header { 
        height: 90px;
        min-width: 400px;
        flex-direction: column;
        justify-content: space-around;
    }

    header > h1 {
        margin: 0px;
    }

    main { margin-top: 90px;}

    footer { 
        min-height: 140px;
        flex-direction: column;
        justify-content: center;
        gap: 10px;
    }

    footer > p {
        margin: 0px;
        text-align: center;
    }
}