:root {
  --primary-color: #2c3e50;
  --secondary-color: #3498db;
  --accent-color: #f39c12;
  --light-bg: #f5f5f5;
  --white: #ffffff;
  --text-color: #333333;
  --border-color: #e0e0e0;
  --success-color: #2ecc71;
  --error-color: #e74c3c;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: 'Work Sans', sans-serif;
  background-color: var(--light-bg);
  color: var(--text-color);
  line-height: 1.6;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

header {
  background-color: var(--primary-color);
  color: var(--white);
  text-align: center;
  padding: 1.5rem 0;
  box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

h1 {
  font-size: 2rem;
  font-weight: 600;
}

.tagline {
  font-size: 1rem;
  opacity: 0.8;
}

.container {
  max-width: 1000px;
  margin: 2rem auto;
  padding: 0 1rem;
  flex: 1;
}

.chess-viewer {
  background-color: var(--white);
  border-radius: 8px;
  box-shadow: 0 3px 10px rgba(0,0,0,0.08);
  padding: 2rem;
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
}

@media (min-width: 768px) {
  .chess-viewer {
    grid-template-columns: minmax(320px, 1fr) 1fr;
  }
}

.board-container {
  display: flex;
  flex-direction: column;
  align-items: center;
}

#board {
  width: 100%;
  max-width: 400px;
  margin: 0 auto;
}

.moves-container {
  display: flex;
  flex-direction: column;
}

.series-name {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 1rem;
  color: var(--primary-color);
}

.controls {
  display: flex;
  align-items: center;
  justify-content: center;
  margin-top: 1rem;
  width: 100%;
}

.slider-container {
  flex: 1;
  margin: 0 10px;
  max-width: 300px;
}

#move-slider {
  width: 100%;
}

.keyboard-help {
  margin-top: 1rem;
  background-color: #f8f9fa;
  padding: 0.8rem;
  border-radius: 4px;
  font-size: 0.9rem;
  text-align: center;
}

.shortcut {
  display: inline-block;
  background-color: #e9ecef;
  padding: 0.2rem 0.4rem;
  border-radius: 3px;
  margin: 0 0.2rem;
  font-family: monospace;
  border: 1px solid #ced4da;
}

button {
  background-color: var(--secondary-color);
  color: var(--white);
  border: none;
  border-radius: 4px;
  padding: 0.5rem 1rem;
  font-family: 'Work Sans', sans-serif;
  font-weight: 500;
  cursor: pointer;
  transition: background-color 0.2s;
}

button:hover {
  background-color: #2980b9;
}

#play-btn {
  background-color: var(--accent-color);
}

#play-btn:hover {
  background-color: #e67e22;
}

.move-list {
  background-color: var(--light-bg);
  border: 1px solid var(--border-color);
  border-radius: 4px;
  padding: 1rem;
  max-height: 300px;
  overflow-y: auto;
  margin-top: 1rem;
}

.move {
  display: inline-block;
  padding: 0.3rem 0.6rem;
  margin: 0.2rem;
  background-color: var(--white);
  border-radius: 4px;
  cursor: pointer;
  user-select: none;
  border: 1px solid var(--border-color);
}

.move.active {
  background-color: var(--secondary-color);
  color: var(--white);
}

.move-number {
  color: #7f8c8d;
  font-weight: 500;
  margin-right: 0.5rem;
}

.original-text {
  margin-top: 1rem;
  padding: 1rem;
  background-color: var(--white);
  border: 1px solid var(--border-color);
  border-radius: 4px;
  font-size: 0.9rem;
}

.original-text-title {
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--primary-color);
}

.cta-container {
  text-align: center;
  background-color: #f8f9fa;
  border-radius: 8px;
  padding: 1.5rem;
  margin-top: 2rem;
  border: 1px solid var(--border-color);
}

.cta-title {
  font-size: 1.3rem;
  font-weight: 600;
  margin-bottom: 1rem;
  color: var(--primary-color);
}

.cta-text {
  margin-bottom: 1.5rem;
}

.cta-button {
  display: inline-block;
  background-color: var(--primary-color);
  color: var(--white);
  border: none;
  border-radius: 4px;
  padding: 0.8rem 1.5rem;
  text-decoration: none;
  font-weight: 600;
  transition: background-color 0.2s;
}

.cta-button:hover {
  background-color: #1a252f;
}

footer {
  background-color: var(--primary-color);
  color: var(--white);
  text-align: center;
  padding: 1rem 0;
  margin-top: auto;
}

.share-links {
  display: flex;
  justify-content: center;
  gap: 1rem;
  margin-top: 1rem;
}

.share-button {
  background-color: var(--white);
  border: 1px solid var(--border-color);
  border-radius: 4px;
  padding: 0.5rem 1rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  transition: background-color 0.2s;
}

.share-button:hover {
  background-color: #f0f0f0;
}