:root {
  --bgcolor: #f8f8ff;
  --txtcolor: #333333;
  --offcolor: #e0e0e0;
  --hsize: 3em;
  --tsize: 1em;
  font-size: 16px;
  --font: "Quicksand", sans-serif;
  --hfont: "Fredoka", sans-serif;
  --concolor: rgba(0, 123, 255, 0.8);
  --shadow: rgba(0, 0, 0, 0.1);
}

/* Global Styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  background: var(--bgcolor);
  color: var(--txtcolor);
  font-family: var(--font);
}

body {
  margin: 0;
  padding: 0 10px;
  width: calc(100vw - 10px);
  min-height: 100vh;
}

h1 {
  display: flex;
  justify-content: center;
  align-items: center;
  font-family: var(--hfont);
  font-size: var(--hsize);
  margin: 2rem 0;
}

/* Book Form */
#book-form {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  max-width: 600px;
  margin: 2rem auto;
  padding: 1rem;
  background-color: white;
  border: 2px solid var(--offcolor);
  border-radius: 12px;
  box-shadow: 0 4px 12px var(--shadow);
}

#book-form input,
#book-form select,
#book-form button {
  font-family: var(--font);
  font-size: 1rem;
  padding: 0.75rem;
  border: 1px solid var(--offcolor);
  border-radius: 6px;
}

#book-form button {
  background-color: var(--concolor);
  color: white;
  cursor: pointer;
  border: none;
  font-size: 1.1rem;
  flex-shrink: 0;
}

/* Filters */
#filter-favorites,
#sort-by {
  margin-left: 0.5rem;
  padding: 0.5rem;
  border: 1px solid var(--offcolor);
  border-radius: 6px;
}

/* Stats */
#stats {
  text-align: center;
  font-size: 1.2rem;
  margin: 1rem 0;
}

/* Book List */
#book-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1rem;
  max-width: 1200px;
  margin: 2rem auto;
}

.book {
  background-color: white;
  border: 2px solid var(--offcolor);
  border-radius: 12px;
  padding: 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  box-shadow: 0 4px 12px var(--shadow);
}

.book.favorite {
  border-color: var(--concolor);
  box-shadow: 0 4px 12px rgba(0, 123, 255, 0.3);
}

/* Book Buttons */
.book button {
  font-family: var(--font);
  font-size: 1rem;
  padding: 0.5rem 1rem;
  border-radius: 6px;
  border: none;
  cursor: pointer;
}

.book .fav {
  background-color: var(--concolor);
  color: white;
}

.book .del {
  background-color: var(--offcolor);
  color: var(--txtcolor);
}

/* Responsive */
@media (max-width: 600px) {
  #book-form {
    flex-direction: column;
  }

  #book-list {
    grid-template-columns: 1fr;
  }
}