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

:root {
  --primary: #0ea5e9;
  --primary-dark: #0284c7;
  --secondary: #06b6d4;
  --hover: #22d3ee;
  --background: #0c1e2e;
  --card-bg: #1a2942;
  --text: #e0f2fe;
  --text-muted: #7dd3fc;
  --success: #06b6d4;
  --danger: #0369a1;
  --shadow: rgba(0, 0, 0, 0.4);
}

body {
  background: linear-gradient(135deg, #0c1e2e 0%, #1a3a52 50%, #0c1e2e 100%);
  min-height: 100vh;
  text-align: center;
  color: var(--text);
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  padding: 20px;
}

h1 {
  margin: 20px 0 30px;
  font-size: 2.5rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  text-shadow: 0 0 30px rgba(14, 165, 233, 0.4);
  animation: fadeInDown 0.6s ease-out;
}

@keyframes fadeInDown {
  from {
    opacity: 0;
    transform: translateY(-20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

main {
  max-width: 800px;
  margin: 0 auto;
}

.btn {
  cursor: pointer;
  width: 160px;
  margin: 15px;
  padding: 15px 25px;
  font-size: 1.3rem;
  font-weight: 600;
  color: var(--text);
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  border: 2px solid transparent;
  border-radius: 15px;
  box-shadow: 0 4px 15px var(--shadow);
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.btn::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
  transition: left 0.5s ease;
}

.btn:hover::before {
  left: 100%;
}

.btn:hover {
  transform: translateY(-3px) scale(1.05);
  box-shadow: 0 8px 25px rgba(14, 165, 233, 0.5);
  background: linear-gradient(135deg, var(--hover), var(--primary));
}

.btn:active {
  transform: translateY(-1px) scale(1.02);
}

.rules-container {
  padding: 25px;
  margin: 20px auto;
  border-radius: 20px;
  border: 2px solid var(--primary);
  background: var(--card-bg);
  color: var(--text);
  box-shadow: 0 8px 30px var(--shadow);
  transition: all 0.3s ease;
  animation: fadeIn 0.8s ease-out;
}

@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

.rules-container:hover {
  box-shadow: 0 12px 40px rgba(99, 102, 241, 0.3);
  border-color: var(--secondary);
}

summary {
  font-weight: 700;
  font-size: 1.4rem;
  cursor: pointer;
  padding: 10px;
  border-radius: 10px;
  transition: all 0.3s ease;
  color: var(--text);
}

summary:hover {
  color: var(--text);
  background: rgba(99, 102, 241, 0.1);
}

.rules-container ul {
  list-style-type: none;
  margin: 15px 0;
}

.rules-container li {
  margin: 8px 0;
  padding: 8px;
  background: rgba(99, 102, 241, 0.1);
  border-radius: 8px;
  transition: all 0.2s ease;
}

.rules-container li:hover {
  background: rgba(99, 102, 241, 0.2);
  transform: translateX(5px);
}

.rules-container p {
  margin: 15px 0;
  line-height: 1.6;
  color: var(--text-muted);
}

@media (min-width: 760px) {
  .rules-container {
    width: 80%;
  }
}

.score-container {
  display: flex;
  justify-content: space-around;
  margin: 40px auto;
  padding: 25px;
  font-size: 1.4rem;
  background: var(--card-bg);
  border-radius: 20px;
  box-shadow: 0 8px 30px var(--shadow);
  max-width: 600px;
  animation: fadeInUp 0.8s ease-out;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.score-container strong {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.score {
  font-weight: 700;
  font-size: 2.5rem;
  background: linear-gradient(135deg, var(--success), var(--primary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% {
    opacity: 1;
  }
  50% {
    opacity: 0.7;
  }
}

.options-container {
  margin: 40px 0;
  padding: 30px;
  background: var(--card-bg);
  border-radius: 20px;
  box-shadow: 0 8px 30px var(--shadow);
  animation: fadeIn 1s ease-out;
}

.options-container h2 {
  margin-bottom: 20px;
  font-size: 1.8rem;
  color: var(--text);
}

.btn-container {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 10px;
}

.results-container {
  font-size: 1.4rem;
  margin: 30px auto;
  padding: 30px;
  background: var(--card-bg);
  border-radius: 20px;
  box-shadow: 0 8px 30px var(--shadow);
  min-height: 150px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
}

#results-msg {
  font-weight: 600;
  margin-bottom: 15px;
  animation: slideIn 0.5s ease-out;
}

@keyframes slideIn {
  from {
    opacity: 0;
    transform: translateX(-20px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

#winner-msg {
  margin-top: 20px;
  font-size: 2rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--success), var(--primary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: bounceIn 0.8s ease-out;
}

@keyframes bounceIn {
  0% {
    opacity: 0;
    transform: scale(0.3);
  }
  50% {
    transform: scale(1.05);
  }
  70% {
    transform: scale(0.9);
  }
  100% {
    opacity: 1;
    transform: scale(1);
  }
}

#reset-game-btn {
  display: none;
  margin: 25px auto;
  background: linear-gradient(135deg, var(--secondary), var(--danger));
}

#reset-game-btn:hover {
  background: linear-gradient(135deg, var(--danger), var(--secondary));
}

/* Responsive design */
@media (max-width: 600px) {
  h1 {
    font-size: 2rem;
  }
  
  .btn {
    width: 130px;
    font-size: 1.1rem;
    margin: 10px;
  }
  
  .score-container {
    font-size: 1.1rem;
    flex-direction: column;
    gap: 20px;
  }
  
  .score {
    font-size: 2rem;
  }
}