:root {
  --bg-color: #92caffa2;          
  --surface-color: #fdfbf7;     
  --surface-alt: #eae4dc;       
  --text-primary: #0f172a;      
  --text-secondary: #475569;    
  --border-color: #0f172a;      
  
  --primary-color: #3965a1;     
  --primary-hover: #1e293b;
  --accent-stamp: #3145c8;      

  --radius-lg: 6px;
  --radius-full: 4px;

  --shadow-tactile: 3px 3px 0px #0f172a;
  --shadow-tactile-hover: 5px 5px 0px #0f172a;
  --shadow-tactile-active: 1px 1px 0px #0f172a;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-tap-highlight-color: transparent;
}


h1 {
  font-family: 'Franklin Gothic Medium', 'Arial Narrow', Arial, sans-serif
}

 h2 {
  font-family: 'Trebuchet MS', 'Lucida Sans Unicode', 'Lucida Grande', 'Lucida Sans', Arial, sans-serif;
 }

body {
  font-family: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  
  background-color: var(--bg-color);
  background-image: repeating-linear-gradient(
    45deg,
    transparent,
    transparent 18px,
    rgba(15, 23, 42, 0.05) 18px,
    rgba(15, 23, 42, 0.05) 25px
  );
  
  color: var(--text-primary);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 2rem 1rem;
  line-height: 1.5;
}

.chessboard-wrapper {
  flex: 1 1 440px;
  max-width: 100%;
  aspect-ratio: 1 / 1; 
  background: var(--surface-color);
  padding: 12px;
  border-radius: var(--radius-lg);
  border: 2px solid var(--border-color);
  box-shadow: var(--shadow-tactile);
}

.site-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: 860px;
  width: 100%;
  margin-bottom: 2rem;
  padding-bottom: 0.75rem;
  border-bottom: 2px solid var(--border-color);
  font-family: 'Trebuchet MS', 'Lucida Sans Unicode', 'Lucida Grande', 'Lucida Sans', Arial, sans-serif;
}

.site-header h1 {
  font-family: 'Lora', Georgia, serif;
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--text-primary);
}

.sub-heading {
  display: block;
  font-size: 0.85rem;
  color: var(--text-secondary);
  font-weight: 500;
}

.tab-navigation {
  display: flex;
  gap: 0.5rem;
}

.tab-navigation .nav-btn {
  font-family: inherit;
  font-size: 0.85rem;
  font-weight: 600;
  background: transparent;
  color: var(--text-primary);
  padding: 0.5rem 1rem;
  border: 2px solid transparent;
  border-radius: var(--radius-full);
  cursor: pointer;
  box-shadow: none;
  transition: all 0.15s ease;
}

.tab-navigation .nav-btn:hover {
  border-color: var(--border-color);
  box-shadow: 2px 2px 0px var(--border-color);
  transform: translate(-1px, -1px);
}

.tab-navigation .nav-btn.active {
  border-color: var(--border-color);
  background-color: var(--surface-color);
  box-shadow: var(--shadow-tactile);
}

.main-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  max-width: 860px;
  width: 100%;
}

.tab-content {
  width: 130%;
}

.game-layout {
  display: flex;
  flex-direction: row;
  flex-wrap: wrap;
  gap: 2rem;
  justify-content: center;
  align-items: stretch;
  width: 100%;
}

.chessboard-wrapper {
  flex: 1 1 440px;
  max-width: 100%;
  background: var(--surface-color);
  padding: 12px;
  border-radius: var(--radius-lg);
  border: 2px solid var(--border-color);
  box-shadow: var(--shadow-tactile);
}

.sidebar {
  display: flex;
  flex-direction: column;
  flex: 1 1 360px;
  max-width: 100%;
}

.card {
  background: var(--surface-color);
  padding: 1.5rem;
  border-radius: var(--radius-lg);
  border: 2px solid var(--border-color);
  box-shadow: var(--shadow-tactile);
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  height: 100%;
}

.card-header-row {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  border-bottom: 2px dashed var(--border-color);
  padding-bottom: 1rem;
}

.card h2,
.card h3 {
  font-family: 'Lora', Georgia, serif;
  color: var(--text-primary);
}

.card h3 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.eval-text {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1;
  background: var(--surface-alt);
  padding: 0.5rem 1rem;
  border: 2px solid var(--border-color);
  border-radius: var(--radius-full);
  box-shadow: 2px 2px 0px var(--border-color);
}

.status-block {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.status-text {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
}

.data-group {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.label {
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.5px;
  color: var(--text-secondary);
  text-transform: uppercase;
}

.code-text {
  font-family: 'JetBrains Mono', monospace;
  background: var(--surface-alt);
  border: 2px solid var(--border-color);
  padding: 0.75rem;
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  word-break: break-all;
  color: var(--text-primary);
}

.button-group {
  display: flex;
  gap: 0.75rem;
  width: 100%;
  margin-top: auto; 
  padding-top: 0.5rem;
}

.button-group .btn {
  font-family: inherit;
  font-size: 0.9rem;
  font-weight: 700;
  padding: 0.85rem 1rem;
  border-radius: var(--radius-full);
  border: 2px solid var(--border-color);
  cursor: pointer;
  box-shadow: var(--shadow-tactile);
  transition: transform 0.1s ease, box-shadow 0.1s ease, background-color 0.2s ease;
  flex: 1;
  text-align: center;
}

.button-group .btn-primary {
  background-color: var(--primary-color);
  color: #ffffff;
}

.button-group .btn-primary:hover {
  background-color: var(--primary-hover);
  transform: translate(-1px, -1px);
  box-shadow: var(--shadow-tactile-hover);
}

.button-group .btn-primary:active {
  transform: translate(2px, 2px);
  box-shadow: var(--shadow-tactile-active);
}

.button-group .btn-secondary {
  background-color: var(--surface-color);
  color: var(--text-primary);
}

.button-group .btn-secondary:hover {
  background-color: var(--surface-alt);
  transform: translate(-1px, -1px);
  box-shadow: var(--shadow-tactile-hover);
}

.button-group .btn-secondary:active {
  transform: translate(2px, 2px);
  box-shadow: var(--shadow-tactile-active);
}

#how-it-works-section .card {
  width: 100%;
  display: block; 
}

#how-it-works-section h2 {
  font-size: 1.6rem;
  margin-bottom: 0.75rem;
}

#how-it-works-section p {
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 0.75rem;
}

.note-box {
  background: var(--surface-alt);
  border-left: 4px solid var(--accent-stamp);
  border-top: 2px solid var(--border-color);
  border-right: 2px solid var(--border-color);
  border-bottom: 2px solid var(--border-color);
  padding: 1rem;
  border-radius: var(--radius-full);
  font-size: 0.9rem;
  margin-top: 1rem;
  color: var(--text-primary);
}