body {
  font-family: Arial, Helvetica, sans-serif;
}

tr[class="read"] {
  background-image: linear-gradient(0deg, green 0%, lime 20%, lime 80%, green 100%);
}

tr[class="to-read"] {
  background-image: linear-gradient(0deg, gray 0%, lightgray 20%, lightgray 80%, gray 100%);
}

tr[class="in-progress"] {
  background-image: linear-gradient(0deg, orange 0%, moccasin 20%, moccasin 80%, orange 100%);
}

tr[class="to-read"] span[class="status"] {
  border: 1px solid darkred;
  background-image: radial-gradient(ellipse at center, salmon 0%, crimson 75%, darkred 100%);
  border-radius: 15px;
  text-align: center;
}

tr[class="read"] span[class="status"] {
  border: 1px solid darkgreen;
  background-image: radial-gradient(ellipse at center, lime 0%, green 75%, darkgreen 100%);
  border-radius: 15px;
  text-align: center;
}

tr[class="in-progress"] span[class="status"] {
  border: 1px solid darkorange;
  background-image: radial-gradient(ellipse at center, moccasin 0%, orange 75%, darkorange 100%);
  border-radius: 15px;
  text-align: center;
}

span[class="status"], span[class^="rate"] {
  height: 20px;
  width: 100px;
  padding: 1px;
}

span[class^="rate"] > span {
  border: 1px solid black;
  border-radius: 15px;
  margin: 1px;
  height: 20px;
  width: 20px;
  background-color: white;
}

span[class~="priority"] {
  border: 1px solid darkred;
  background-image: radial-gradient(ellipse at center, salmon 0%, crimson 75%, darkred 100%);
  border-radius: 15px;
  text-align: center;
  height: 20px;
  width: 20px;
}

span[class~="one"] > :first-child {
  background-image: radial-gradient(ellipse at center, violet 0%, darkviolet 75%, purple 100%);
}

span[class~="two"] > :nth-child(-n+2) {
  background-image: radial-gradient(ellipse at center, violet 0%, darkviolet 75%, purple 100%);
}

span[class~="three"] span {
  background-image: radial-gradient(ellipse at center, violet 0%, darkviolet 75%, purple 100%);
}

h1 {
  text-align: center;
}

span {
  display: inline-block;
}

thead {
  background-image: linear-gradient(0deg, skyblue 0%, lightcyan 20%, lightcyan 80%, skyblue 100%);
  text-align: left;
}

table {
  border-collapse: collapse;
  width: 100%;
  table-layout: fixed;
  min-width: 900px;
}

th:nth-child(1) { width: 20%; } /* Title */
th:nth-child(2) { width: 15%; } /* Author */
th:nth-child(3) { width: 15%; } /* Category */
th:nth-child(4) { width: 8%; }  /* Format */
th:nth-child(5) { width: 12%; } /* Source */
th:nth-child(6) { width: 10%; } /* Priority */
th:nth-child(7) { width: 10%; } /* Status */
th:nth-child(8) { width: 10%; } /* Rate */

tbody tr {
  transition: filter 0.2s ease;
  cursor: default;
}

tbody td {
  padding: 4px 6px;
}

tbody td:first-child {
  vertical-align: top;
  padding-top: 8px;
}

tbody tr:hover {
  filter: brightness(1.12);
  outline: 2px solid #555;
  outline-offset: -2px;
}

summary {
  cursor: pointer;
  font-weight: bold;
}

summary:hover {
  text-decoration: none;
}

details p {
  background-color: rgba(255, 255, 255, 0.35);
  border-radius: 6px;
  padding: 10px;
  margin: 8px 8px 8px 0;
  max-width: 300px;
  font-size: 0.9rem;
  line-height: 1.5;
}

.about-books {
  margin: 30px auto;
  padding: 20px 25px;
  max-width: 900px;

  background-image: linear-gradient(
    135deg,
    lightcyan 0%,
    aliceblue 60%,
    skyblue 100%
  );

  border-left: 5px solid steelblue;
  border-radius: 10px;

  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);

  transition: box-shadow 0.2s ease;
}

.about-books h2 {
  margin-top: 0;
  margin-bottom: 12px;
  color: #234e70;
  font-size: 1.5rem;
}

.about-books p {
  margin: 0;
  line-height: 1.7;
  font-size: 1rem;
  color: #333;
}

.about-books p + p {
  margin-top: 15px;
}

.about-books:hover {
  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.22);
}

.main-books {
  overflow-x: auto;
}