:root {
  --primary-color: #3498db;
  --secondary-color: #2c3e50;
  --background-color: #ecf0f1;
  --pane-background: #ffffff;
  --border-color: #bdc3c7;
  --text-color: #333;
  --light-text-color: #ffffff;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen,
    Ubuntu, Cantarell, "Open Sans", "Helvetica Neue", sans-serif;
  margin: 0;
  background-color: var(--background-color);
  color: var(--text-color);
  display: flex;
  flex-direction: column;
  height: 100vh;
}

header,
footer .credit {
  background-color: var(--secondary-color);
  color: var(--light-text-color);
  padding: 1rem;
  text-align: center;
  flex-shrink: 0;
}

h1 {
  margin: 0;
  font-size: 1.5rem;
}

.theme-switcher {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.9rem;
}

.toggle-checkbox {
  display: none;
}

.toggle-label {
  display: block;
  width: 40px;
  height: 22px;
  background-color: #ccc;
  border-radius: 11px;
  position: relative;
  cursor: pointer;
  transition: background-color 0.2s;
}

.toggle-label::after {
  content: "";
  position: absolute;
  width: 18px;
  height: 18px;
  background-color: white;
  border-radius: 50%;
  top: 2px;
  left: 2px;
  transition: transform 0.2s;
}

.toggle-checkbox:checked + .toggle-label {
  background-color: var(--primary-color);
}

.toggle-checkbox:checked + .toggle-label::after {
  transform: translateX(18px);
}

.white-text {
  color: var(--light-text-color);
}

.container {
  display: flex;
  flex: 1;
  overflow: hidden;
  padding: 10px;
  gap: 10px;
}

.editor-pane,
.preview-pane {
  background-color: var(--pane-background);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  display: flex;
  flex-direction: column;
  width: 50%;
  overflow: hidden;
}

#markdown-input {
  flex: 1;
  border: none;
  padding: 15px;
  font-size: 1rem;
  line-height: 1.6;
  resize: none;
  background-color: transparent;
  color: var(--text-color);
}

#markdown-input:focus {
  outline: none;
}

.tabs {
  display: flex;
  border-bottom: 1px solid var(--border-color);
}

.tab-button {
  padding: 10px 15px;
  cursor: pointer;
  border: none;
  background-color: transparent;
  font-size: 1rem;
  color: var(--text-color);
  border-bottom: 2px solid transparent;
}

.tab-button.active {
  border-bottom-color: var(--primary-color);
  font-weight: bold;
}

.tab-content {
  display: none;
  flex-direction: column;
  height: 100%;
}

.tab-content.active {
  display: flex;
}

#custom-css-input {
  flex: 1;
  border: none;
  padding: 15px;
  font-size: 0.9rem;
  line-height: 1.5;
  resize: none;
  background-color: transparent;
  color: var(--text-color);
  font-family: monospace;
}

#custom-css-input:focus {
  outline: none;
}

.css-presets {
  display: flex;
  gap: 10px;
  padding: 10px;
  border-bottom: 1px solid var(--border-color);
  background-color: #f9f9f9;
}

.preset-btn {
  padding: 8px 12px;
  border: 1px solid var(--border-color);
  background-color: #fff;
  cursor: pointer;
  border-radius: 4px;
  transition: all 0.2s ease;
}

.preset-btn:hover {
  background-color: var(--primary-color);
  color: var(--light-text-color);
  border-color: var(--primary-color);
}

.preset-btn.active {
  background-color: var(--primary-color);
  color: var(--light-text-color);
  border-color: var(--primary-color);
  font-weight: bold;
}

.file-controls {
  padding: 10px;
  border-top: 1px solid var(--border-color);
  background-color: #f9f9f9;
}

input[type="file"] {
  display: none;
}

label[for="file-input"] {
  cursor: pointer;
  padding: 8px 12px;
  background-color: var(--primary-color);
  color: var(--light-text-color);
  border-radius: 4px;
  font-size: 0.9rem;
  transition: background-color 0.3s;
}

label[for="file-input"]:hover {
  background-color: #2980b9;
}

.preview-pane {
  position: relative;
}

#pdf-preview {
  flex: 1;
  border: none;
  width: 100%;
  height: 100%;
}

#loader {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(255, 255, 255, 0.8);
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: 1.2rem;
  z-index: 10;
}

.hidden {
  display: none !important;
}

footer {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 15px;
}

#download-pdf,
#copy-png-btn {
  background-color: var(--primary-color);
  color: var(--light-text-color);
  border: none;
  padding: 12px 25px;
  font-size: 1rem;
  font-weight: bold;
  border-radius: 5px;
  cursor: pointer;
  transition: background-color 0.3s;
}

#download-pdf:hover,
#copy-png-btn:hover {
  background-color: #2980b9;
}

#copy-png-btn {
  background-color: #27ae60;
}

#copy-png-btn:hover {
  background-color: #229954;
}

.mermaid-container {
  text-align: center;
  margin-bottom: 1em;
}

.credit {
  text-align: center;
  padding: 1rem;
  font-size: 0.9em;
  color: #777;
}

@media (max-width: 768px) {
  .container {
    flex-direction: column;
    height: auto;
  }

  .editor-pane,
  .preview-pane {
    width: 100%;
    height: 50vh;
  }
}