:root {
  --background-color: #292929;
  --text-color: #e9e9e9;
  --button-color: #6F7275;
  --button-hover-color: #484950;
  --button-text-color: #e9e9e9;
  --border-radius: 0.5em;
  --transition-speed: 0.3s;
}

/* Utility & layout */
.centered-container {
  margin: 0 auto;
  text-align: center;
  max-width: 450px;
  font-family: Arial, sans-serif;
  background-color: var(--background-color);
  color: var(--text-color);
  padding: 1em;
  font-size: 1em;
}

/* Typography */
.app-title {
  font-size: 2em;
}

.section-title {
  font-size: 1.5em;
}

.song-count {
  font-size: 0.875em;
  font-style: italic;
  opacity: 0.8;
}

.instructions {
  line-height: 1.5;
  text-align: justify;
}

/* Progress & warnings */
.progress-indicator,
.comparison-text {
  font-weight: bold;
  margin-bottom: 1em;
}

.warning {
  font-size: 0.75em;
  font-style: italic;
}

/* Footer and source */
footer {
  margin-top: 0;
}

.source {
  font-size: 0.75em;
  font-style: italic;
  background: transparent;
  position: fixed;
  bottom: 0;
  right: 2em;
}

#resultsInterface {
  margin: 0 auto;
  max-width: 95%;
}

#resultsInterface:not([hidden]) ~ footer .source {
  position: relative;
  bottom: auto;
  right: auto;
  margin-bottom: 0;
  text-align: right;
  width: 100%;
}

a {
  color: var(--text-color);
  border-bottom: 1px solid var(--text-color);
  text-decoration: none;
  transition: color var(--transition-speed) ease, border-color var(--transition-speed) ease;
}

a:hover {
  color: var(--button-hover-color);
  border-bottom-color: var(--button-hover-color);
}

a:active {
  color: var(--button-color);
  border-bottom-color: var(--button-color);
}