body {
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  max-width: 1100px;
  margin: 0 auto;
  padding: 20px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  min-height: 100vh;
  color: #1a1a1a;
}

.container {
  background: #ffffff;
  border-radius: 15px;
  padding: 30px;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
}

h1 {
  color: #667eea;
  text-align: center;
  margin-bottom: 10px;
}

.intro {
  background: #f0f4ff;
  padding: 20px;
  border-radius: 10px;
  margin-bottom: 20px;
  border-left: 5px solid #667eea;
}

.intro h3 {
  margin-top: 0;
  color: #667eea;
}

.grid-container {
  text-align: center;
  margin: 30px 0;
}

.sudoku-grid {
  display: inline-grid;
  grid-template-columns: repeat(9, 55px);
  grid-template-rows: repeat(9, 55px);
  gap: 0;
  border: 3px solid #000;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
}

.cell {
  width: 55px;
  height: 55px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 26px;
  font-weight: bold;
  background: #ffffff;
  border-right: 1px solid #bbb;
  border-bottom: 1px solid #bbb;
  box-sizing: border-box;
  transition: all 0.2s ease;
}

.cell:nth-child(9n+3) {
  border-right: 3px solid #000;
}

.cell:nth-child(9n+6) {
  border-right: 3px solid #000;
}

.cell:nth-child(n+19):nth-child(-n+27) {
  border-bottom: 3px solid #000;
}

.cell:nth-child(n+46):nth-child(-n+54) {
  border-bottom: 3px solid #000;
}

.cell:nth-child(9n) {
  border-right: none;
}

.cell:nth-child(n+73) {
  border-bottom: none;
}

.cell.given {
  background: #e3f2fd;
  color: #1565c0;
  font-weight: 700;
}

.cell.filled {
  background: #c8e6c9;
  color: #2e7d32;
  animation: fillIn 0.5s ease;
}

.cell.highlight-row {
  background: #fff9c4;
}

.cell.highlight-col {
  background: #ffe0b2;
}

.cell.focus {
  background: #ffd54f !important;
  box-shadow: inset 0 0 15px rgba(255, 193, 7, 0.8);
  transform: scale(1.02);
  z-index: 5;
}

@keyframes fillIn {
  0% {
    transform: scale(0.95);
    opacity: 0;
  }
  50% {
    transform: scale(1.02);
  }
  100% {
    transform: scale(1);
    opacity: 1;
  }
}
.explanation {
  background: #fffbf0;
  padding: 25px;
  border-radius: 10px;
  margin: 25px 0;
  border-left: 6px solid #ff9800;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.explanation h3 {
  color: #e65100;
  margin-top: 0;
}

.technique {
  background: #e8f5e9;
  padding: 15px;
  border-radius: 8px;
  margin: 15px 0;
  border-left: 5px solid #4caf50;
  font-weight: 500;
}

.checking {
  background: #fff3e0;
  padding: 15px;
  border-radius: 8px;
  margin: 15px 0;
  font-family: "Courier New", monospace;
}

.controls {
  text-align: center;
  margin: 30px 0;
}

button {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  border: none;
  padding: 15px 35px;
  font-size: 17px;
  border-radius: 10px;
  cursor: pointer;
  margin: 10px 15px;
  transition: all 0.3s ease;
  box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
  font-weight: 600;
}

button:hover:not(:disabled) {
  transform: translateY(-3px);
  box-shadow: 0 6px 20px rgba(102, 126, 234, 0.6);
}

button:disabled {
  background: linear-gradient(135deg, #bbb 0%, #999 100%);
  cursor: not-allowed;
  opacity: 0.6;
}

.step-counter {
  text-align: center;
  font-size: 22px;
  color: #667eea;
  font-weight: bold;
  margin: 20px 0;
  padding: 15px;
  background: #f5f5f5;
  border-radius: 10px;
}

.legend {
  display: flex;
  justify-content: center;
  gap: 25px;
  margin: 25px 0;
  flex-wrap: wrap;
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 15px;
  background: #f5f5f5;
  border-radius: 8px;
}

.legend-box {
  width: 35px;
  height: 35px;
  border: 2px solid #333;
  border-radius: 5px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: bold;
}

.completed {
  background: linear-gradient(135deg, #11998e 0%, #38ef7d 100%);
  color: white;
  padding: 30px;
  border-radius: 15px;
  text-align: center;
  font-size: 24px;
  margin: 30px 0;
  display: none;
  box-shadow: 0 5px 20px rgba(56, 239, 125, 0.4);
}

.progress {
  background: #f5f5f5;
  height: 10px;
  border-radius: 5px;
  overflow: hidden;
  margin: 20px 0;
}

.progress-bar {
  background: linear-gradient(90deg, #667eea 0%, #764ba2 100%);
  height: 100%;
  transition: width 0.3s ease;
}

/*# sourceMappingURL=styles.css.map */