* {
  box-sizing: border-box;
}

:root {
  --primary-color: #FF3B30;
  --primary-dark: #E62E24;
  --primary-light: #FF5449;
  --white: #FFFFFF;
  --gray-100: #F5F5F5;
  --gray-200: #EEEEEE;
  --gray-300: #E0E0E0;
  --gray-600: #666666;
  --gray-800: #333333;
  --text-dark: #2C3E50;
}

body {
  margin: 0;
  font-family: system-ui, sans-serif;
  color: var(--gray-800);
  background-color: var(--gray-100);
  line-height: 1.6;
}

nav {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  padding: 1rem;
  gap: 0.8rem;
  border-bottom: solid 1px var(--gray-300);
  background-color: var(--white);
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

nav a {
  display: inline-block;
  min-width: 9rem;
  padding: 0.7rem 1rem;
  border-radius: 0.3rem;
  border: solid 1px var(--gray-300);
  text-align: center;
  text-decoration: none;
  color: var(--gray-600);
  transition: all 0.3s ease;
}

nav a:hover {
  background-color: var(--gray-200);
  color: var(--primary-color);
  border-color: var(--primary-color);
}

nav a[aria-current='page'] {
  color: var(--white);
  background-color: var(--primary-color);
  border-color: var(--primary-color);
}

nav a[aria-current='page']:hover {
  background-color: var(--primary-dark);
  color: var(--white);
}

main {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem;
}

h1 {
  font-weight: bold;
  font-size: 2.5rem;
  color: var(--primary-color);
  margin-bottom: 1rem;
  letter-spacing: -0.5px;
  text-align: center;
}

h2 {
  font-size: 2rem;
  color: var(--text-dark);
  margin-bottom: 1.5rem;
}

p {
  color: var(--gray-600);
  font-size: 1.1rem;
  margin-bottom: 1.5rem;
  max-width: 800px;
}

.subtitle {
  text-align: center;
  margin: 0 auto 2rem;
}

.logo {
  display: block;
  width: 150px;
  height: auto;
  margin: 1rem auto;
}

.content-center {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  margin: 0 auto;
  max-width: 800px;
}

.contact-form {
  max-width: 500px;
  width: 100%;
  background: var(--white);
  padding: 2rem;
  border-radius: 0.5rem;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

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

.form-group label {
  display: block;
  margin-bottom: 0.5rem;
  color: var(--gray-800);
  font-weight: 500;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 0.75rem;
  border: 1px solid var(--gray-300);
  border-radius: 0.3rem;
  font-size: 1rem;
  transition: border-color 0.3s ease;
}

.form-group textarea {
  min-height: 150px;
  resize: vertical;
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 2px var(--primary-light);
}

.form-group input.error,
.form-group textarea.error {
  border-color: #ff0000;
  background-color: rgba(255, 0, 0, 0.05);
}

.form-status {
  margin-top: 1rem;
  padding: 0.75rem;
  border-radius: 0.3rem;
  text-align: center;
  display: none;
}

.form-status.success {
  display: block;
  background-color: rgba(0, 128, 0, 0.1);
  color: #006400;
  border: 1px solid #006400;
}

.form-status.error {
  display: block;
  background-color: rgba(255, 0, 0, 0.1);
  color: #8b0000;
  border: 1px solid #8b0000;
}

button[type="submit"] {
  background-color: var(--primary-color);
  color: var(--white);
  padding: 0.75rem 1.5rem;
  border: none;
  border-radius: 0.3rem;
  font-size: 1rem;
  cursor: pointer;
  transition: background-color 0.3s ease;
}

button[type="submit"]:hover {
  background-color: var(--primary-dark);
}

.downloads-section {
  margin-top: 2rem;
}

.downloads-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 1.5rem;
  margin-top: 1.5rem;
}

.download-card {
  background: var(--white);
  padding: 1.5rem;
  border-radius: 0.5rem;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
  text-align: center;
  transition: transform 0.2s ease;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.download-card:hover {
  transform: translateY(-2px);
}

.download-card h3 {
  margin: 1rem 0;
  color: var(--text-dark);
  font-size: 1.1rem;
  line-height: 1.4;
}

.book-cover {
  width: 180px;
  height: 240px;
  object-fit: cover;
  border-radius: 0.3rem;
  box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.download-button {
  display: inline-block;
  background-color: var(--primary-color);
  color: var(--white);
  padding: 0.75rem 1.5rem;
  border-radius: 0.3rem;
  text-decoration: none;
  transition: background-color 0.3s ease;
  margin-top: auto;
}

.download-button:hover {
  background-color: var(--primary-dark);
}

.content-section {
  margin-bottom: 3rem;
}

.content-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1.5rem;
}

.content-card {
  background: var(--white);
  padding: 1.5rem;
  border-radius: 0.5rem;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
  display: flex;
  flex-direction: column;
  height: 100%;
}

.content-card h3 {
  margin: 0 0 1rem;
  color: var(--text-dark);
  font-size: 1.2rem;
  line-height: 1.4;
}

.content-link {
  display: inline-block;
  background-color: var(--primary-color);
  color: var(--white);
  padding: 0.75rem 1.5rem;
  border-radius: 0.3rem;
  text-decoration: none;
  transition: background-color 0.3s ease;
  margin-top: auto;
}

.content-link:hover {
  background-color: var(--primary-dark);
  color: var(--white);
}

.button-group {
  display: flex;
  gap: 0.5rem;
  margin-top: auto;
}
/* Regras de responsividade */
@media (max-width: 768px) {
  nav {
    flex-direction: column;
  }
  
  nav a {
    width: 100%;
  }
  
  .content-grid,
  .downloads-grid {
    grid-template-columns: 1fr;
  }
  
  h1 {
    font-size: 2rem;
  }
  
  h2 {
    font-size: 1.5rem;
  }
  
  .logo {
    width: 120px;
  }
  
  main {
    padding: 1rem;
  }
}

/* Animações */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

.content-card.animated,
.download-card.animated {
  animation: fadeIn 0.5s ease forwards;
}