body {
  font-family: 'Segoe UI', sans-serif;
  margin: 0;
  background: #f1fdf2;
  color: #333;
  transition: background 0.3s, color 0.3s;
}

.dark-mode {
  background: #121212;
  color: #f1f1f1;
}

header {
  background: #81c784;
  color: white;
  padding: 20px;
  text-align: center;
}

nav {
  margin-top: 10px;
  display: flex;
  justify-content: center;
  gap: 20px;
  flex-wrap: wrap;
}

nav a, #theme-toggle {
  color: white;
  text-decoration: none;
  font-weight: bold;
  background: transparent;
  border: none;
  cursor: pointer;
}

.hero {
  text-align: center;
  background: #c8e6c9;
  padding: 60px 20px;
}

.section-title {
  text-align: center;
  font-size: 26px;
  color: #2e7d32;
  margin: 30px 0;
}

.services {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  justify-content: center;
}

.service {
  flex: 1 1 300px;
  background: white;
  padding: 20px;
  border-radius: 10px;
  box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.quiz-container {
  max-width: 700px;
  margin: auto;
  background: white;
  padding: 25px;
  border-radius: 10px;
}

.question {
  margin-bottom: 20px;
}

label {
  display: block;
  margin: 5px 0;
}

button {
  background: #43a047;
  color: white;
  padding: 10px 20px;
  font-size: 16px;
  border: none;
  margin-top: 15px;
  border-radius: 5px;
  cursor: pointer;
}

button:hover {
  background: #2e7d32;
}

.result {
  font-weight: bold;
  margin-top: 20px;
}

#timer {
  text-align: right;
  font-weight: bold;
  margin-bottom: 10px;
}

.progress-bar-container {
  background: #eee;
  border-radius: 20px;
  overflow: hidden;
  height: 15px;
  margin-top: 20px;
}

.progress-bar {
  height: 100%;
  width: 0%;
  background: #66bb6a;
  transition: width 0.3s;
}

.certificate {
  background: #dcedc8;
  color: #2e7d32;
  padding: 15px;
  margin-top: 20px;
  border-radius: 10px;
  font-size: 18px;
  text-align: center;
}