/* RESET E BODY */
body {
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background-color: #f0f0f0; /* grigio chiaro di sfondo generale */
  color: #222; /* testo principale scuro */
}

/* HEADER */
header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 5px 10px;
  background-color: #111; /* nero intenso */
  color: #fff;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: 50px;
}

header h1 {
  flex: 1;
  text-align: center;
  margin: 0;
}

header img {
  height: 40px;
}

#header-label {
  font-weight: normal;
  font-size: 0.85em;
  margin-right: 5px;
  color: #ccc;
}

/* FOOTER */
footer {
  text-align: center;
  padding: 5px 10px;
  background-color: #111; /* nero intenso */
  color: #fff;
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  height: 25px;
  line-height: 25px;
  font-size: 0.9em;
}

/* LAYOUT PRINCIPALE */
main {
  display: flex;
  flex: 1;
  margin-top: 50px;
  margin-bottom: 25px;
  height: calc(100vh - 75px);
  overflow: hidden;
}

/* SIDEBAR */
.sidebar {
  width: 250px;
  background: linear-gradient(to bottom, #e0e0e0, #c0c0c0); /* sfumatura grigia */
  border-right: 1px solid #aaa;
  display: flex;
  flex-direction: column;
  padding: 10px;
  position: fixed;
  top: 50px;
  bottom: 25px;
  left: 0;
  box-sizing: border-box;
  overflow-y: auto;
}

.sidebar h2 {
  margin: 2px 0 10px 0;
  color: #111;
}

/* Lista capitoli */
#chapter-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-bottom: 10px;
}

/* Singolo capitolo */
.chapter-item {
  cursor: pointer;
  transition: 0.2s;
  background: #f4f4f4;
  border: 1px solid #bbb;
  border-radius: 5px;
  padding: 6px 8px;
}

.chapter-item:hover {
  background: #e0e0e0;
}

.chapter-item.active {
  background-color: #bbb; /* evidenziazione capitolo selezionato */
  border-color: #888;
}

/* Pulsanti capitoli */
.chapter-nav {
  display: flex;
  justify-content: space-between;
  margin-top: 10px;
}

.chapter-nav button {
  flex: 1;
  margin: 0 3px;
  padding: 6px;
  border: none;
  border-radius: 4px;
  background: #444; /* grigio scuro */
  color: #fff;
  font-weight: bold;
  cursor: pointer;
  transition: background 0.2s;
}

.chapter-nav button:hover {
  background: #666; /* leggermente più chiaro al passaggio */
}

/* PDF SECTION */
.pdf-section {
  flex: 1;
  margin-left: 250px;
  padding: 10px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  background: linear-gradient(to bottom, #dcdcdc, #c0c0c0); /* grigio centrale */
}

/* Pulsanti zoom */
.zoom-controls {
  display: flex;
  justify-content: flex-end;
  padding: 5px 0;
  gap: 5px;
}

.zoom-controls button {
  padding: 5px 10px;
  border: none;
  border-radius: 4px;
  background-color: #444;
  color: white;
  font-weight: bold;
  cursor: pointer;
  transition: background 0.2s;
}

.zoom-controls button:hover {
  background-color: #666;
}

/* CONTAINER PDF */
.chapter-container {
  width: 100%;
  max-width: 1200px;
}

.chapter-container canvas {
  display: block;
  margin: 10px auto;
  max-width: 100%;
  background: white;
  box-shadow: 0 2px 6px rgba(0,0,0,0.2);
}