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

body {
  font-family: 'Jost', 'Imprima', sans-serif;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 20px;
}

.landing-container {
  background: white;
  border-radius: 15px;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
  padding: 40px;
  max-width: 800px;
  width: 100%;
}

h1 {
  text-align: center;
  color: #333;
  margin-bottom: 10px;
  font-size: 2.5em;
}

.subtitle {
  text-align: center;
  color: #666;
  margin-bottom: 40px;
  font-size: 1.1em;
}

.section {
  margin-bottom: 30px;
}

.section h2 {
  color: #667eea;
  margin-bottom: 15px;
  font-size: 1.3em;
}

.button-group {
  display: grid;
  gap: 15px;
  margin-bottom: 20px;
}

.section:first-of-type .button-group {
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
}

.section:nth-of-type(2) .button-group {
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
}

.category-btn {
  padding: 0;
  border: 3px solid #ddd;
  background: white;
  color: #333;
  border-radius: 8px;
  cursor: pointer;
  font-weight: 500;
  transition: all 0.3s ease;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-end;
  overflow: hidden;
  height: 200px;
  position: relative;
}

.category-btn img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  position: absolute;
  top: 0;
  left: 0;
}

.category-btn span {
  position: relative;
  z-index: 2;
  background: rgba(255, 255, 255, 0.95);
  width: 100%;
  padding: 10px;
  text-align: center;
  font-size: 1em;
}

.category-btn:hover {
  border-color: #667eea;
  transform: translateY(-2px);
  box-shadow: 0 5px 15px rgba(102, 126, 234, 0.3);
}

.category-btn.active {
  border-color: #667eea;
  box-shadow: 0 0 0 4px rgba(102, 126, 234, 0.3);
}

.category-btn.active span {
  background: #667eea;
  color: white;
}

.activity-btn {
  padding: 15px 20px;
  border: 2px solid #ddd;
  background: white;
  color: #333;
  border-radius: 8px;
  cursor: pointer;
  font-size: 1em;
  font-weight: 500;
  transition: all 0.3s ease;
}

.activity-btn:hover {
  border-color: #667eea;
  background: #f0f4ff;
  transform: translateY(-2px);
}

.activity-btn.active {
  background: #667eea;
  color: white;
  border-color: #667eea;
}

#numberInputSection {
  background: #f9f9f9;
  padding: 20px;
  border-radius: 8px;
  border: 2px solid #ddd;
}

#numberInputSection label {
  display: block;
  margin-bottom: 10px;
  color: #333;
  font-weight: 500;
}

#numberInput {
  width: 100%;
  padding: 12px;
  border: 2px solid #ddd;
  border-radius: 6px;
  font-size: 1em;
  margin-bottom: 10px;
}

#numberInput:focus {
  outline: none;
  border-color: #667eea;
  box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.start-btn {
  width: 100%;
  padding: 15px;
  background: #667eea;
  color: white;
  border: none;
  border-radius: 8px;
  font-size: 1.1em;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
}

.start-btn:hover:not(:disabled) {
  background: #764ba2;
  transform: translateY(-2px);
  box-shadow: 0 5px 20px rgba(102, 126, 234, 0.4);
}

.start-btn:disabled {
  background: #ccc;
  cursor: not-allowed;
  opacity: 0.6;
}

.error-message {
  color: #e74c3c;
  text-align: center;
  margin-top: 15px;
  font-weight: 500;
  min-height: 20px;
}

@media (max-width: 600px) {
  .landing-container {
    padding: 20px;
  }

  h1 {
    font-size: 1.8em;
  }

  .button-group {
    grid-template-columns: 1fr;
  }

  .category-btn,
  .activity-btn {
    padding: 12px 15px;
    font-size: 0.95em;
  }
}