/* GENERAL */
:root {
  --header-height: calc(2em + 4px + 20px);
}
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-family: Arial, Ubuntu, Helvetica, sans-serif;

  scroll-snap-type: both mandatory;
  scroll-behavior: smooth;
  scroll-padding-top: var(--header-height);
  overflow: auto;
}

section {
  width: 100%;
  height: calc(100vh - var(--header-height));
  scroll-snap-align: center;
}

section:first-of-type {
  height: 100vh;
}

/* HEADER */

.header {
  position: fixed;

  display: flex;
  justify-content: space-between;

  color: white;
  background-color: transparent;

  width: 100%;
  padding: 10px;

  z-index: 1;

  transition: all 0.25s;
}

.header.active {
  color: black;
  background-color: white;
  box-shadow: 0 2px 10px white;
}

.header h2 {
  font-size: 2em;
}

.header a {
  color: inherit;
  text-decoration: none;
}

.header a:hover {
  text-decoration: underline;
}

.header a:focus {
  outline: 1px white dashed;
}

.header__nav {
  display: flex;
  align-items: center;
}

.header__nav ul {
  list-style: none;

  display: flex;
  flex-direction: row;
}

.header__nav li {
  font-size: 1.3em;
  margin-right: 15px;
}