:root {
  --primary-color: #3498db;
  --secondary-color: #2c3e50;
  --background-color: #ecf0f1;
  --text-color: #34495e;
  --highlight-color: #e74c3c;
  --button-min-width: 100px;
  --button-height: 36px;
  --button-font-size: 14px;
}

body {
  font-family: 'Roboto', Arial, sans-serif;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  height: 100vh;
  overflow: hidden;
  background-color: var(--background-color);
  color: var(--text-color);
}

#top-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 15px;
  background-color: rgba(52, 152, 219, 0.4);
  color: white;
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
  backdrop-filter: blur(5px);
}

#file-input {
  color: transparent;
}

#file-input::before {
  content: 'Choose PDF';
  display: inline-block;
  min-width: var(--button-min-width);
  height: var(--button-height);
  padding: 0 15px;
  font-size: var(--button-font-size);
  background: var(--secondary-color);
  color: white;
  border-radius: 3px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

#page-navigation {
  display: flex;
  align-items: center;
}

#current-page {
  margin-right: 15px;
  font-weight: bold;
}

#page-input {
  width: 60px;
  margin-right: 10px;
  padding: 5px;
  border: none;
  border-radius: 3px;
}

#left-panel {
  flex-grow: 1;
  width: 70%;
  overflow-y: auto;
  padding: 20px;
  box-sizing: border-box;
  height: 100vh;
}

#right-panel {
  transform: scale(1);
  transform-origin: top right;
  width: 30%;
  height: 100vh;
  position: fixed;
  right: 0;
  top: 0;
  padding: 20px;
  box-sizing: border-box;
  overflow-y: auto;
  background-color: white;
  box-shadow: -2px 0 5px rgba(0, 0, 0, 0.1);
}

#file-input,
#mode-toggle,
#top-controls {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 15px;
}

#settings-icon {
  cursor: pointer;
  font-size: 24px;
  line-height: 1;
}

.mode-btn {
  flex: 1;
  padding: 10px;
  border: 1px solid var(--secondary-color);
  background-color: white;
  color: var(--secondary-color);
  cursor: pointer;
  transition: all 0.3s ease;
}

.mode-btn:not(:last-child) {
  margin-right: 10px;
}

.mode-btn.selected {
  background-color: var(--secondary-color);
  color: white;
  transform: scale(1.05);
}

.mode-btn:hover:not(.selected) {
  background-color: var(--background-color);
}

#page-navigation {
  display: flex;
  align-items: center;
}

#page-input {
  width: 60px;
  margin-right: 10px;
  padding: 5px;
  border: 1px solid #ddd;
  border-radius: 3px;
}

#settings-panel {
  margin-top: 15px;
}

#api-key-input,
#model-select {
  margin-bottom: 15px;
  width: 100%;
  padding: 8px;
  border: 1px solid #ddd;
  border-radius: 3px;
}

#pdf-viewer {
  border: 1px solid #ddd;
  background-color: white;
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

.page {
  position: relative;
  margin-bottom: 20px;
}

.text-layer {
  position: absolute;
  left: 0;
  top: 0;
  right: 0;
  bottom: 0;
  overflow: hidden;
  opacity: 0.7;
  line-height: 1.0;
}

.text-layer > span {
  color: transparent;
  position: absolute;
  white-space: pre;
  cursor: text;
  transform-origin: 0% 0%;
}

::selection {
  background: rgba(52, 152, 219, 0.3);
}

.highlight {
  background-color: rgba(255, 255, 0, 0.4);
}

#system-prompt, #explain-prompt, #language-prompt {
  width: 100%;
  height: 150px;
  margin-bottom: 15px;
  padding: 10px;
  border: 1px solid #ddd;
  border-radius: 3px;
  resize: vertical;
}

#explain-prompt, #language-prompt {
  display: none;
}

#flashcards {
  border: 1px solid #ddd;
  padding: 15px;
  margin-top: 15px;
  background-color: white;
  border-radius: 3px;
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

.flashcard {
  margin-bottom: 15px;
  padding: 15px;
  border: 1px solid #ddd;
  background-color: white;
  border-radius: 3px;
  transition: box-shadow 0.3s ease;
  font-size: 16px;
}

.flashcard:hover {
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

.explanation-content {
  white-space: pre-wrap;
  text-align: left;
  margin-bottom: 15px;
}

.explanation-content br {
  display: block;
  margin-bottom: 5px;
}

.remove-btn {
  float: right;
  background-color: var(--highlight-color);
  color: white;
  border: none;
  padding: 5px 10px;
  border-radius: 3px;
  cursor: pointer;
  transition: background-color 0.3s ease;
}

.remove-btn:hover {
  background-color: #c0392b;
}

#recent-pdfs {
  margin-top: 20px;
}

#recent-pdfs h3 {
  margin-bottom: 10px;
  color: var(--secondary-color);
}

#recent-pdfs ul {
  padding-left: 20px;
  list-style-type: none;
}

#recent-pdfs li {
  margin-bottom: 5px;
}

#recent-pdfs a {
  color: var(--primary-color);
  text-decoration: none;
  transition: color 0.3s ease;
}

#recent-pdfs a:hover {
  color: #2980b9;
}

/* Modal styles */
.modal {
  display: none;
  position: fixed;
  z-index: 1000;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  overflow: auto;
  background-color: rgba(0,0,0,0.4);
}

.modal-content {
  background-color: #fefefe;
  margin: 5% auto;
  padding: 20px;
  border: 1px solid #888;
  width: 80%;
  max-width: 800px;
  max-height: 80vh;
  overflow-y: auto;
}

.close {
  color: #aaa;
  float: right;
  font-size: 28px;
  font-weight: bold;
}

.close:hover,
.close:focus {
  color: black;
  text-decoration: none;
  cursor: pointer;
}

/* Markdown styles */
#explanationModalContent {
  font-family: -apple-system,BlinkMacSystemFont,Segoe UI,Helvetica,Arial,sans-serif,Apple Color Emoji,Segoe UI Emoji;
  font-size: 16px;
  line-height: 1.8;
  word-wrap: break-word;
}

#explanationModalContent h1,
#explanationModalContent h2,
#explanationModalContent h3,
#explanationModalContent h4,
#explanationModalContent h5,
#explanationModalContent h6 {
  margin-top: 24px;
  margin-bottom: 16px;
  font-weight: 600;
  line-height: 1.25;
}

#explanationModalContent h1 { font-size: 32px; }
#explanationModalContent h2 { font-size: 24px; }
#explanationModalContent h3 { font-size: 20px; }
#explanationModalContent h4 { font-size: 16px; }
#explanationModalContent h5 { font-size: 14px; }
#explanationModalContent h6 { font-size: 13px; }

#explanationModalContent p {
  margin-top: 0;
  margin-bottom: 16px;
}

#explanationModalContent code {
  padding: 0.2em 0.4em;
  margin: 0;
  font-size: 14px;
  background-color: rgba(27,31,35,0.05);
  border-radius: 3px;
}

#explanationModalContent pre {
  padding: 16px;
  overflow: auto;
  font-size: 85%;
  line-height: 1.45;
  background-color: #f6f8fa;
  border-radius: 3px;
}

#explanationModalContent ul,
#explanationModalContent ol {
  padding-left: 2em;
  margin-top: 0;
  margin-bottom: 16px;
}

#explanationModalContent img {
  max-width: 100%;
  box-sizing: content-box;
  background-color: #fff;
}

#explanationModalContent blockquote {
  padding: 0 1em;
  color: #6a737d;
  border-left: 0.25em solid #dfe2e5;
  margin: 0 0 16px 0;
}

/* Button styles */
.mode-btn,
#go-to-page-btn,
#submit-btn,
#add-to-collection-btn,
#clear-collection-btn,
#export-csv-btn {
  min-width: var(--button-min-width);
  height: var(--button-height);
  padding: 0 15px;
  font-size: var(--button-font-size);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

#go-to-page-btn,
#zoom-in-btn,
#zoom-out-btn {
  background-color: var(--secondary-color);
  color: white;
  border: none;
  border-radius: 3px;
  cursor: pointer;
  transition: background-color 0.3s ease;
  margin-right: 5px;
}

#go-to-page-btn:hover,
#zoom-in-btn:hover,
#zoom-out-btn:hover {
  background-color: #34495e;
}

#zoom-in-btn,
#zoom-out-btn {
  width: 30px;
  height: 30px;
  font-size: 18px;
  line-height: 1;
  padding: 0;
}

#submit-btn {
  width: 100%;
  margin-bottom: 15px;
  background-color: var(--primary-color);
  color: white;
  border: none;
  border-radius: 3px;
  cursor: pointer;
  transition: background-color 0.3s ease;
}

#submit-btn:hover {
  background-color: #2980b9;
}

#add-to-collection-btn,
#clear-collection-btn,
#export-csv-btn {
  width: 100%;
  margin-bottom: 10px;
  background-color: var(--secondary-color);
  color: white;
  border: none;
  border-radius: 3px;
  cursor: pointer;
  transition: background-color 0.3s ease;
}

#add-to-collection-btn:hover,
#clear-collection-btn:hover,
#export-csv-btn:hover {
  background-color: #34495e;
}

/* Media query for small screens and high zoom levels */
@media screen and (max-width: 768px), screen and (min-resolution: 2dppx) {
  #top-bar {
    flex-wrap: wrap;
  }

  #file-input,
  #mode-toggle,
  #page-navigation {
    width: 100%;
    margin-bottom: 10px;
  }

  #right-panel {
    width: 100%;
    position: static;
    height: auto;
  }

  #left-panel {
    width: 100%;
  }
}