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

body {
  font-family: 'Roboto', sans-serif;
  background-color: #f9f9f9;
  color: #333;
  transition: background-color 0.3s ease, color 0.3s ease;
}

body.dark-mode {
  background-color: #1e1e1e;
  color: #f1f1f1;
}

header {
  text-align: center;
  padding: 2rem 1rem;
  background-color: #fff;
  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.dark-mode header {
  background-color: #2c2c2c;
}

.subtitle {
  margin-top: 0.5rem;
  color: #666;
}

button#toggleTheme {
  margin-top: 1rem;
  padding: 0.5rem 1rem;
  border: none;
  background-color: #333;
  color: #fff;
  border-radius: 5px;
  cursor: pointer;
  transition: background-color 0.3s;
}

button#toggleTheme:hover {
  background-color: #555;
}

.faq-container {
  max-width: 800px;
  margin: 2rem auto;
  padding: 0 1rem;
}

.faq-item {
  background-color: #fff;
  border-radius: 8px;
  margin-bottom: 1rem;
  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
  overflow: hidden;
  transition: all 0.3s ease;
}

.dark-mode .faq-item {
  background-color: #2c2c2c;
}

.faq-question {
  padding: 1rem;
  cursor: pointer;
  font-weight: bold;
  position: relative;
}

.faq-question:hover {
  background-color: #f1f1f1;
}

.dark-mode .faq-question:hover {
  background-color: #3a3a3a;
}

.faq-answer {
  padding: 0 1rem 1rem;
  display: none;
  animation: fadeIn 0.3s ease-in-out;
}

.faq-item.active .faq-answer {
  display: block;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(-5px); }
  to { opacity: 1; transform: translateY(0); }
}

#scrollToTopBtn {
  position: fixed;
  bottom: 30px;
  right: 30px;
  display: none;
  background-color: #333;
  color: white;
  border: none;
  padding: 0.6rem 1rem;
  border-radius: 50px;
  font-size: 1rem;
  cursor: pointer;
  box-shadow: 0 2px 10px rgba(0,0,0,0.2);
  z-index: 100;
}

#scrollToTopBtn:hover {
  background-color: #555;
}

@media (max-width: 600px) {
  header h1 {
    font-size: 1.5rem;
  }
  .faq-question {
    font-size: 1rem;
  }
}