:root {
  --primary-color: #4361ee;
  --primary-dark: #3f37c9;
  --primary-light: #4cc9f0;
  --background-color: #f8f9fa;
  --card-color: #ffffff;
  --example-bg: #e7f5ff;
  --example-border: #339af0;
  --interactive-bg: #f0f7ff;
  --text-color: #212529;
  --secondary-text: #495057;
  --success-color: #40c057;
  --warning-color: #fd7e14;
  --level-color: #7950f2;
  --border-radius: 12px;
  --button-radius: 8px;
  --shadow: 0 4px 16px rgba(0, 0, 0, 0.08);
  --strong-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
  --cell-size: 50px;
  --icon-size: 32px;
  --transition-speed: 0.25s;
}

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

body {
  background-color: var(--background-color);
  color: var(--text-color);
  line-height: 1.7;
  font-family: "Inter", "Roboto", -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue", Arial, sans-serif;
  font-size: 16px;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 30px 20px;
}

header {
  background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
  color: white;
  text-align: center;
  padding: 40px 20px;
  border-radius: var(--border-radius);
  margin-bottom: 35px;
  box-shadow: var(--strong-shadow);
}

header p {
  color: #fff;
}

h1 {
  font-size: 42px;
  margin-bottom: 15px;
  font-weight: 700;
  letter-spacing: 0.5px;
}

h2 {
  color: var(--primary-color);
  margin: 30px 0 20px;
  border-bottom: 2px solid var(--primary-light);
  padding-bottom: 10px;
  font-size: 28px;
  font-weight: 600;
}

h3 {
  font-size: 22px;
  margin-bottom: 15px;
  color: var(--primary-dark);
  font-weight: 600;
}

p {
  margin-bottom: 20px;
  font-size: 18px;
  line-height: 1.7;
  color: var(--secondary-text);
}

.interactive {
  background-color: var(--interactive-bg);
  border-radius: var(--border-radius);
  padding: 35px;
  margin-bottom: 40px;
  box-shadow: var(--shadow);
}

.game-container {
  display: flex;
  flex-direction: row;
  gap: 30px;
  margin: 25px 0;
  align-items: flex-start;
}

.game-column {
  flex: 1;
  min-width: 0;
}

.field-column {
  flex-basis: 40%;
}

.controls-column {
  flex-basis: 60%;
  display: flex;
  flex-direction: column;
  gap: 25px;
}

.commands-section,
.program-section {
  background-color: rgba(255, 255, 255, 0.9);
  border-radius: var(--border-radius);
  padding: 20px;
  box-shadow: var(--shadow);
}

.program {
  min-height: 150px;
  max-height: 300px;
  overflow-y: auto;
  margin-bottom: 20px;
  border: 2px dashed var(--primary-light);
  border-radius: 10px;
  padding: 20px;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  background-color: rgba(255, 255, 255, 0.7);
}

.commands {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
  margin: 15px 0;
}

.robot-field {
  display: grid;
  gap: 4px;
  margin: 20px auto;
  width: max-content;
  background-color: #eee;
  padding: 12px;
  border-radius: 12px;
  box-shadow: inset 0 0 15px rgba(0, 0, 0, 0.1);
}

.cell {
  width: var(--cell-size);
  height: var(--cell-size);
  background-color: white;
  border: 1px solid #e9ecef;
  border-radius: 6px;
  display: flex;
  justify-content: center;
  align-items: center;
  transition: background-color 0.2s;
  position: relative;
}

.wall {
  background-color: #9a6348;
  border: 1px solid #7d5b4f;
}

.cell:hover {
  background-color: #f8f9fa;
}

.robot-icon {
  font-size: var(--icon-size);
  color: var(--primary-color);
  filter: drop-shadow(2px 2px 3px rgba(0, 0, 0, 0.2));
  z-index: 10;
  transition: transform 0.3s ease;
}

.collectible {
  font-size: var(--icon-size);
  filter: drop-shadow(2px 2px 3px rgba(0, 0, 0, 0.2));
  z-index: 5;
}

.command {
  padding: 12px 16px;
  background-color: var(--primary-color);
  color: white;
  border-radius: var(--button-radius);
  cursor: pointer;
  text-align: center;
  font-weight: 500;
  transition: all var(--transition-speed) ease;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.15);
  font-size: 15px;
  border: none;
}

.command:hover {
  background-color: var(--primary-dark);
  transform: translateY(-3px);
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
}

.command:active {
  transform: translateY(-1px);
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.15);
}

.program-step {
  padding: 10px 16px;
  background-color: #e9ecef;
  border-radius: 8px;
  display: flex;
  align-items: center;
  font-size: 15px;
  transition: all var(--transition-speed) ease;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.08);
  margin: 4px;
}

.program-step.active {
  background-color: #fee2e2;
  transform: scale(1.05);
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.12);
}

.command-icon {
  display: inline-block;
  font-weight: 500;
}

.repeat-container {
  display: flex;
  align-items: center;
  margin-left: 12px;
  padding: 3px 8px;
  background-color: rgba(255, 255, 255, 0.7);
  border-radius: 6px;
  border: 1px solid #dee2e6;
}

.repeat-label {
  font-weight: 600;
  color: var(--secondary-text);
  margin-right: 5px;
}

.repeat-input {
  width: 35px;
  height: 26px;
  border: 1px solid #ced4da;
  border-radius: 4px;
  text-align: center;
  font-size: 14px;
  font-weight: 500;
  transition: border-color var(--transition-speed) ease, box-shadow var(--transition-speed) ease;
}

.repeat-input:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.2);
}

.delete-step {
  margin-left: 12px;
  cursor: pointer;
  color: #fa5252;
  font-weight: bold;
  transition: transform var(--transition-speed) ease;
}

.delete-step:hover {
  transform: scale(1.2);
  color: #e03131;
}

.level-progress {
  display: flex;
  gap: 12px;
  margin-bottom: 25px;
  flex-wrap: wrap;
}

.level-btn {
  padding: 8px 16px;
  background-color: #e9ecef;
  color: var(--text-color);
  border-radius: var(--button-radius);
  cursor: pointer;
  text-align: center;
  transition: all var(--transition-speed) ease;
  font-weight: 500;
  font-size: 15px;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

.level-btn.active {
  background-color: var(--level-color);
  color: white;
  font-weight: 600;
}

.level-btn:hover {
  background-color: #dee2e6;
  transform: translateY(-2px);
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

.level-btn.active:hover {
  background-color: #6741d9;
}

.level-btn.completed {
  background-color: var(--success-color);
  color: white;
}

.toast {
  position: fixed;
  bottom: 30px;
  left: 50%;
  transform: translateX(-50%);
  background-color: var(--success-color);
  color: white;
  padding: 15px 30px;
  border-radius: 10px;
  display: none;
  z-index: 1000;
  font-size: 18px;
  font-weight: 500;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15);
}

.controls {
  display: flex;
  gap: 15px;
  justify-content: center;
  flex-wrap: wrap;
  margin-top: 20px;
}

button {
  background-color: var(--primary-color);
  color: white;
  border: none;
  padding: 12px 24px;
  border-radius: var(--button-radius);
  cursor: pointer;
  font-size: 16px;
  font-weight: 600;
  margin: 10px 8px;
  transition: all var(--transition-speed) ease;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}

button:hover {
  background-color: var(--primary-dark);
  transform: translateY(-3px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

button:active {
  transform: translateY(-1px);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

footer {
  background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
  color: white;
  text-align: center;
  padding: 2.5rem 0;
  border-radius: 20px 20px 0 0;
  margin-top: 4rem;
  box-shadow: 0 -4px 12px rgba(0, 0, 0, 0.1);
}

footer p {
  font-size: 1.1rem;
  color: white;
  margin-bottom: 0;
}

.level-description {
  background-color: var(--example-bg);
  border-left: 5px solid var(--example-border);
  padding: 20px;
  margin-bottom: 25px;
  border-radius: 8px;
  font-size: 17px;
  line-height: 1.6;
  color: var(--secondary-text);
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.05);
}

@media (max-width: 768px) {
  .container {
    padding: 15px;
  }

  header {
    padding: 25px 15px;
  }

  h1 {
    font-size: 32px;
  }

  h2 {
    font-size: 24px;
  }

  p {
    font-size: 16px;
  }

  .interactive {
    padding: 25px;
  }

  .game-container {
    flex-direction: column;
    gap: 20px;
  }

  .field-column,
  .controls-column {
    flex-basis: 100%;
    width: 100%;
  }

  :root {
    --cell-size: 40px;
    --icon-size: 26px;
  }

  .commands {
    grid-template-columns: repeat(2, 1fr);
    gap: 10px;
  }

  .command {
    padding: 10px 14px;
    font-size: 14px;
  }
  
  .level-description {
    font-size: 15px;
    padding: 15px;
  }
  
  .level-btn {
    padding: 6px 12px;
    font-size: 14px;
  }
}

#runBtn {
  background-color: var(--success-color);
}

#stopBtn {
  background-color: #fa5252;
}

#clearBtn {
  background-color: var(--warning-color);
}