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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  background: linear-gradient(135deg, #66d6ea 0%, #918fff 100%);
  min-height: 100vh;
  padding: 1rem;
  line-height: 1.6;
}

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

nav.main-nav {
  background: white;
  border-radius: 1rem;
  padding: 1rem;
  margin-bottom: 2rem;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

nav.main-nav ul {
  list-style: none;
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  justify-content: center;
}

nav.main-nav a {
  padding: 0.75rem 1.5rem;
  background: #667eea;
  color: white;
  text-decoration: none;
  border-radius: 0.5rem;
  font-weight: 500;
  transition: all 0.2s;
  display: inline-block;
}

nav.main-nav a:hover {
  background: #764ba2;
  transform: translateY(-2px);
}

nav.main-nav a:focus {
  outline: 2px solid #667eea;
  outline-offset: 2px;
}

nav.main-nav a.active {
  background: #2c51f3;
}

main {
  background: white;
  border-radius: 1rem;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
  padding: 2rem;
}

h1 {
  font-size: 2rem;
  color: #2d3748;
  margin-bottom: 0.5rem;
  text-align: center;
}

.intro-text {
  color: #4a5568;
  text-align: center;
  margin-bottom: 2rem;
  font-size: 1rem;
}

.form-group {
  margin-bottom: 1.5rem;
}

label {
  display: block;
  margin-bottom: 0.5rem;
  color: #2d3748;
  font-weight: 500;
  font-size: 0.95rem;
}

label .required {
  color: #e53e3e;
  margin-left: 0.25rem;
}

input[type="text"],
input[type="email"],
textarea {
  width: 100%;
  padding: 0.75rem;
  border: 2px solid #e2e8f0;
  border-radius: 0.5rem;
  font-family: inherit;
  font-size: 1rem;
  transition: border-color 0.2s;
}

input[type="text"]:focus,
input[type="email"]:focus,
textarea:focus {
  outline: none;
  border-color: #667eea;
  box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

input[type="text"].error,
input[type="email"].error,
textarea.error {
  border-color: #e53e3e;
}

textarea {
  resize: vertical;
  min-height: 120px;
}

.error-message {
  color: #e53e3e;
  font-size: 0.875rem;
  margin-top: 0.5rem;
  display: none;
}

.error-message.show {
  display: block;
}

.success-message {
  background: #c6f6d5;
  color: #22543d;
  padding: 1rem;
  border-radius: 0.5rem;
  margin-bottom: 1.5rem;
  display: none;
  border-left: 4px solid #38a169;
}

.success-message.show {
  display: block;
}

button {
  background: #667eea;
  color: white;
  padding: 0.75rem 2rem;
  border: none;
  border-radius: 0.5rem;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  width: 100%;
}

button:hover {
  background: #764ba2;
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

button:focus {
  outline: 2px solid #667eea;
  outline-offset: 2px;
}

button:active {
  transform: translateY(0);
}

@media (max-width: 640px) {
  main {
    padding: 1.5rem;
  }

  h1 {
    font-size: 1.5rem;
  }

  nav.main-nav ul {
    flex-direction: column;
  }

  nav.main-nav a {
    width: 100%;
    text-align: center;
  }
}

@media (min-width: 768px) {
  main {
    padding: 2.5rem;
  }
}