/* Fonts & Variables */
@import url('https://fonts.googleapis.com/css2?family=Outfit:wght@300;400;500;600;700&family=JetBrains+Mono:wght@400;500;700&display=swap');

:root {
  --font-sans: 'Outfit', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;

  /* Colors */
  --bg-app: #0b0f19;
  --bg-card: #151d30;
  --bg-card-hover: #1e2942;
  --border-color: #24324f;
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  
  --color-accent: #8b5cf6; /* Violet */
  --color-accent-hover: #7c3aed;
  
  /* Board Colors */
  --board-bg: #14532d;
  --board-grid: #166534;
  --board-border: #0f172a;
  
  /* Responsive Cell size variable */
  --cell-size: 70px;

  /* Settings Variables (Controlled via JS) */
  --coord-show: block;
  --coord-size: 14px;
  --move-num-show: block;
  --move-num-size: 11px;
  --db-val-size: 15px;
  --db-cov-size: 9px;
  
  /* Shadow & Animation */
  --shadow-lg: 0 10px 25px -5px rgba(0, 0, 0, 0.4), 0 8px 10px -6px rgba(0, 0, 0, 0.4);
  --shadow-inset: inset 0 2px 4px 0 rgba(0, 0, 0, 0.2);
  --transition-smooth: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
  font-family: var(--font-sans);
  background-color: var(--bg-app);
  color: var(--text-primary);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
}

/* App Header */
.app-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px 24px;
  background-color: var(--bg-card);
  border-bottom: 1px solid var(--border-color);
  z-index: 50;
}

.header-left {
  display: flex;
  align-items: center;
  gap: 12px;
}

.logo-badge {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: linear-gradient(135deg, #fff 50%, #000 50%);
  border: 2px solid var(--border-color);
  box-shadow: var(--shadow-lg);
}

.header-title {
  font-size: 1.25rem;
  font-weight: 600;
  letter-spacing: -0.025em;
  background: linear-gradient(to right, #ffffff, #94a3b8);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* Header Buttons */
.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.btn-icon {
  background: none;
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  width: 40px;
  height: 40px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: var(--transition-smooth);
}

.btn-icon:hover {
  background-color: var(--bg-card-hover);
  border-color: var(--color-accent);
}

/* Main Workspace */
.workspace {
  flex: 1;
  display: flex;
  flex-direction: row;
  max-width: 1400px;
  width: 100%;
  margin: 0 auto;
  padding: 24px;
  gap: 24px;
}

@media (max-width: 1024px) {
  .workspace {
    flex-direction: column;
    padding: 8px 16px 16px 16px;
    gap: 16px;
  }
}

/* Board Column */
.board-column {
  flex: 1.2;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-start;
  padding-top: 12px;
}

/* Board Wrapper and Coordinates Grid */
.board-outer-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  background-color: var(--bg-card);
  padding: 20px;
  border-radius: 16px;
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-lg);
}

.board-label-row {
  display: flex;
  width: calc(8 * var(--cell-size));
  justify-content: space-around;
  font-family: var(--font-sans);
  font-weight: 600;
  font-size: var(--coord-size);
  color: var(--text-secondary);
  height: 24px;
  align-items: center;
  display: var(--coord-show);
}

.board-label-row.top {
  margin-bottom: 8px;
}

.board-label-row.bottom {
  margin-top: 8px;
}

.board-label-row span {
  display: inline-block;
  width: var(--cell-size);
  text-align: center;
}

.board-middle-row {
  display: flex;
  align-items: center;
}

.board-label-col {
  display: flex;
  flex-direction: column;
  height: calc(8 * var(--cell-size));
  justify-content: space-around;
  font-family: var(--font-sans);
  font-weight: 600;
  font-size: var(--coord-size);
  color: var(--text-secondary);
  width: 24px;
  text-align: center;
  display: var(--coord-show);
}

.board-label-col.left {
  margin-right: 8px;
}

.board-label-col.right {
  margin-left: 8px;
}

.board-label-col span {
  display: block;
  height: var(--cell-size);
  line-height: var(--cell-size);
}

/* Othello Felt Board Grid */
.othello-grid {
  display: grid;
  grid-template-columns: repeat(8, var(--cell-size));
  grid-template-rows: repeat(8, var(--cell-size));
  background-color: var(--board-border);
  padding: 6px;
  border-radius: 12px;
  box-shadow: var(--shadow-lg);
  gap: 2px;
  touch-action: none;
}

/* Cell Styles */
.othello-cell {
  background-color: var(--board-bg);
  border-radius: 2px;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  cursor: pointer;
  transition: background-color 0.15s ease;
}

.othello-cell:hover {
  background-color: var(--board-grid);
}

.othello-cell.last-move-cell {
  box-shadow: inset 0 0 0 3px rgba(251, 113, 133, 0.8); /* Red border for last move */
}

/* Discs (Stones) with 3D and Flip effects */
.disc-container {
  width: calc(0.85 * var(--cell-size));
  height: calc(0.85 * var(--cell-size));
  perspective: 1000px;
}

.disc-inner {
  width: 100%;
  height: 100%;
  position: relative;
  transform-style: preserve-3d;
  transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.disc-inner.black-side {
  transform: rotateY(0deg);
}

.disc-inner.white-side {
  transform: rotateY(180deg);
}

.disc-face {
  position: absolute;
  width: 100%;
  height: 100%;
  border-radius: 50%;
  backface-visibility: hidden;
  box-shadow: 0 4px 6px -1px rgba(0,0,0,0.4), inset 0 -3px 4px rgba(0,0,0,0.4), inset 0 3px 4px rgba(255,255,255,0.2);
}

.disc-face.black {
  background: radial-gradient(circle at 30% 30%, #475569 0%, #0f172a 70%);
  transform: rotateY(0deg);
}

.disc-face.white {
  background: radial-gradient(circle at 30% 30%, #ffffff 0%, #cbd5e1 70%);
  transform: rotateY(180deg);
}

.move-num-label {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-family: var(--font-sans);
  font-weight: 700;
  font-size: var(--move-num-size);
  pointer-events: none;
  display: var(--move-num-show);
  z-index: 10;
}

.move-num-label.on-black {
  color: #94a3b8;
}

.move-num-label.on-white {
  color: #334155;
}

/* Legal Move hint dot */
.legal-hint {
  width: 12px;
  height: 12px;
  background-color: rgba(255, 255, 255, 0.15);
  border-radius: 50%;
  transition: var(--transition-smooth);
}

.othello-cell:hover .legal-hint {
  background-color: rgba(255, 255, 255, 0.35);
  transform: scale(1.3);
}

/* DB Value Overlay on Empty Squares */
.db-val-overlay {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  font-family: var(--font-sans);
  font-weight: 600;
  line-height: 1.1;
  pointer-events: none;
}

.score-positive {
  color: #4ade80; /* Light green */
}

.score-negative {
  color: #f87171; /* Light red */
}

.score-neutral {
  color: #cbd5e1; /* White/grey */
}

.db-val-overlay .db-val {
  font-size: var(--db-val-size);
}

.db-val-overlay .db-cov {
  font-size: var(--db-cov-size);
  opacity: 0.7;
}

/* Control Panel Column */
.panel-column {
  flex: 0.8;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

@media (max-width: 1024px) {
  .panel-column {
    width: 100%;
    max-width: 480px;
    margin: 0 auto;
  }
}

/* Panel Card Container */
.panel-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 20px;
  box-shadow: var(--shadow-lg);
  display: flex;
  flex-direction: column;
}

.panel-title {
  font-size: 0.95rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-secondary);
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 10px;
  margin-bottom: 16px;
}

/* Score Board */
.score-board {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background-color: #0b0f19;
  border-radius: 12px;
  padding: 12px 16px;
  margin-bottom: 16px;
}

.score-item {
  display: flex;
  align-items: center;
  gap: 10px;
}

.score-indicator-black, .score-indicator-white {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  box-shadow: inset 0 -2px 3px rgba(0,0,0,0.3);
}

.score-indicator-black {
  background: radial-gradient(circle at 30% 30%, #475569 0%, #0f172a 70%);
}

.score-indicator-white {
  background: radial-gradient(circle at 30% 30%, #ffffff 0%, #cbd5e1 70%);
  border: 1px solid #94a3b8;
}

.score-info {
  display: flex;
  flex-direction: column;
}

.score-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  font-weight: 500;
}

.score-val {
  font-size: 1.15rem;
  font-weight: 700;
}

.score-divider {
  width: 1px;
  height: 32px;
  background-color: var(--border-color);
}

.turn-tag {
  font-size: 0.8rem;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: 6px;
  text-align: center;
}

.turn-black {
  background-color: #0f172a;
  color: #fff;
  border: 1px solid var(--border-color);
}

.turn-white {
  background-color: #fff;
  color: #0f172a;
  border: 1px solid #cbd5e1;
}

/* Stat Grid */
.stat-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-bottom: 16px;
}

.stat-box {
  background-color: #0b0f19;
  border-radius: 12px;
  padding: 12px;
  display: flex;
  flex-direction: column;
  border: 1px solid var(--border-color);
}

.stat-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  margin-bottom: 4px;
}

.stat-value {
  font-size: 1.25rem;
  font-weight: 700;
}

/* Sequence Clipboard Panel */
.clipboard-box {
  background-color: #0b0f19;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 10px 12px;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: #38bdf8;
  word-break: break-all;
  min-height: 40px;
  display: flex;
  align-items: center;
  margin-bottom: 12px;
}

.btn-group {
  display: flex;
  gap: 8px;
  margin-bottom: 12px;
}

.btn {
  font-family: var(--font-sans);
  font-weight: 600;
  font-size: 0.85rem;
  padding: 10px 16px;
  border-radius: 8px;
  cursor: pointer;
  transition: var(--transition-smooth);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  border: 1px solid transparent;
  flex: 1;
}

.btn-primary {
  background-color: var(--color-accent);
  color: #fff;
}

.btn-primary:hover {
  background-color: var(--color-accent-hover);
}

.btn-secondary {
  background-color: #1a243d;
  border-color: var(--border-color);
  color: var(--text-primary);
}

.btn-secondary:hover {
  background-color: var(--bg-card-hover);
}

.input-text {
  background-color: #0b0f19;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  color: #fff;
  padding: 8px 12px;
  font-family: var(--font-sans);
  font-size: 0.85rem;
  width: 100%;
  outline: none;
  transition: var(--transition-smooth);
}

.input-text:focus {
  border-color: var(--color-accent);
}

/* Navigation buttons (|<, <, >, >|) */
.nav-row {
  display: flex;
  gap: 8px;
  margin-top: 16px;
  width: 100%;
}

.nav-row .btn {
  font-family: var(--font-mono);
  font-size: 1rem;
  padding: 8px;
}

/* Settings Modal */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(4px);
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s ease;
}

.modal-overlay.open {
  opacity: 1;
  pointer-events: auto;
}

.modal-container {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  width: 90%;
  max-width: 440px;
  box-shadow: var(--shadow-lg);
  transform: scale(0.95);
  transition: transform 0.2s cubic-bezier(0.34, 1.56, 0.64, 1);
  overflow: hidden;
}

.modal-overlay.open .modal-container {
  transform: scale(1);
}

.modal-header {
  padding: 16px 20px;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.modal-title {
  font-size: 1.1rem;
  font-weight: 600;
}

.modal-close {
  background: none;
  border: none;
  color: var(--text-secondary);
  font-size: 1.5rem;
  cursor: pointer;
  line-height: 1;
}

.modal-close:hover {
  color: #fff;
}

.modal-body {
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

/* Settings Controls Row */
.setting-row {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.setting-label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.setting-label span.value-badge {
  background-color: #0b0f19;
  color: #38bdf8;
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.75rem;
  font-family: var(--font-mono);
}

.setting-control-check {
  display: flex;
  align-items: center;
  gap: 10px;
  cursor: pointer;
}

.setting-control-check input[type="checkbox"] {
  width: 18px;
  height: 18px;
  accent-color: var(--color-accent);
  cursor: pointer;
}

/* Custom range input styling */
.slider-input {
  width: 100%;
  height: 6px;
  border-radius: 3px;
  background-color: #0b0f19;
  outline: none;
  accent-color: var(--color-accent);
  cursor: pointer;
}

/* Responsive board scaling */
@media (min-width: 1400px) {
  :root {
    --cell-size: 88px; /* ~1.5x larger board */
  }
}

@media (min-width: 1200px) and (max-width: 1399px) {
  :root {
    --cell-size: 78px;
  }
}

@media (max-width: 1024px) {
  :root {
    --cell-size: 60px;
  }
}

@media (max-width: 600px) {
  :root {
    --cell-size: calc((100vw - 86px) / 8);
    --db-val-size: 11px;
    --db-cov-size: 7px;
  }
  .workspace {
    padding: 8px;
    gap: 12px;
  }
  .board-column {
    padding-top: 4px;
    width: 100%;
  }
  .board-outer-container {
    padding: 8px;
    border-radius: 12px;
    width: 100%;
    max-width: 100%;
    box-sizing: border-box;
  }
  .othello-grid {
    padding: 4px;
    gap: 1px;
  }
  .board-label-col {
    width: 12px;
    font-size: 11px;
  }
  .board-label-col.left {
    margin-right: 3px;
  }
  .board-label-col.right {
    margin-left: 3px;
  }
  .board-label-row {
    height: 18px;
    font-size: 11px;
  }
  .board-label-row.top {
    margin-bottom: 3px;
  }
  .board-label-row.bottom {
    margin-top: 3px;
  }
  .nav-row {
    margin-top: 10px;
    gap: 4px;
    width: 100%;
  }
  .nav-row .btn {
    padding: 8px;
    font-size: 0.9rem;
  }
}