index.css

body {
  font-family: Arial, sans-serif;
  padding: 0;
  margin: 0;
}

.add-book {
  display: none;
}

#book-collection {
  text-align: center;
}

h1 {
  margin-bottom: 50px;
  font-size: x-large;
  font-weight: 200;
}

#book-list {
  width: 80%;
  display: flex;
  margin: 0 auto;
  flex-wrap: wrap;
  justify-content: center;
  border: 1px solid;
}

.book {
  width: 30rem;
  height: 1rem;
  display: flex;
  flex-direction: row;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  align-content: center;
  padding: 3px;
}

.book:nth-child(even) {
  background-color: lightgray;
}

#add-book-form {
  display: flex;
  margin-top: -5rem;
  flex-direction: column;
  flex-wrap: wrap;
  align-content: center;
  gap: 1rem;
  align-items: center;
}

#add-button {
  margin-left: 8rem;
  border: 1px solid;
}

#add-book-form label {
  margin-right: 10px;
  border: 1px solid;
}

h2 {
  font-size: smaller;
}

#remove-button {
  margin-left: 10rem;
  margin-right: -0.2rem;
  border: 1px solid;
}

h3 {
  font-size: smaller;
}

h4 {
  margin-top: 4rem;
}

.line {
  height: 91px;
  position: relative;
  width: 2px;
  top: -7.5rem;
  rotate: 90deg;
  left: 19rem;
  background-color: #464242;
}

#header {
  font-size: large;
  margin-left: 1rem;
  font-weight: 100;
}

a {
  text-decoration: none;
}

#contact-info-link {
  color: black;
}

#books-link {
  border-right: 2px solid;
  border-color: blue;
  padding-right: 10px;
  color: blue;
}

#add-book-link {
  border-right: 2px solid;
  border-color: black;
  padding-right: 10px;
  color: black;
}

#footer {
  position: relative;
  top: 55px;
}

.dugmici {
  display: flex;
  flex-direction: row;
  flex-wrap: wrap;
  align-items: center;
  gap: 1rem;
  justify-content: flex-end;
  margin-top: -66px;
  padding-right: 1rem;
}

#DateTime {
  display: flex;
  justify-content: flex-end;
  margin-right: 8px;
  font-size: small;
}

.pravougaonik {
  border: 2px solid;
  height: 51px;
  margin: 7px;
}

.kockodugic {
  border: 2px solid;
  display: flex;
  height: 2rem;
  margin: 5px;
  margin-top: 169px;
  flex-direction: row;
  align-items: center;
}

h5 {
  margin-left: 6px;
}