/* Reset e fonte base */
body {
  margin: 0;
  padding: 0;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background-color: #f4f6f8;
  color: #2c3e50;
  line-height: 1.5;
  font-size: 1rem;
}

/* Header com degradê azul (igual página inicial) */
header {
  background: linear-gradient(135deg, #1e3a8a, #2563eb);
  color: white;
  padding: 40px 20px;
  /* Reduzi de 60px para 40px */
  text-align: center;
  box-shadow: 0 4px 10px rgba(30, 58, 138, 0.4);
}

header h1 {
  font-size: 2.5rem;
  /* Reduzi de 3rem para 2.5rem */
  margin-bottom: 10px;
  /* Reduzi de 15px para 10px */
  font-weight: 700;
}

/* Navegação */
nav {
  max-width: 900px;
  margin: 0.5rem auto 1.5rem auto;
  /* Menos espaço acima e abaixo */
  padding: 0 1rem;
}

nav a.btn {
  background-color: #2563eb;
  color: white;
  padding: 12px 24px;
  /* Reduzi padding horizontal e vertical */
  border-radius: 12px;
  font-weight: 700;
  text-decoration: none;
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.45);
  /* leve aumento para destaque */
  transition: background-color 0.3s ease, box-shadow 0.3s ease, transform 0.2s ease;
  display: inline-block;
}

nav a.btn:hover,
nav a.btn:focus {
  background-color: #1e40af;
  box-shadow: 0 6px 18px rgba(30, 64, 175, 0.7);
  transform: scale(1.06);
  outline: none;
}

/* Main container */
main {
  max-width: 900px;
  margin: 20px auto 40px auto;
  /* Reduzi margens top e bottom */
  padding: 0 20px;
  background: white;
  border-radius: 12px;
  box-shadow: 0 4px 20px rgba(44, 62, 80, 0.1);
}

/* Sections */
section {
  margin-bottom: 25px;
  /* Reduzi bastante (de 40px para 25px) */
  padding-bottom: 8px;
  /* Leve redução */
  border-bottom: 1px solid #e1e4e8;
}

section:last-child {
  border-bottom: none;
}

section h2 {
  color: #2563eb;
  font-size: 1.7rem;
  /* Reduzi de 2rem para 1.7rem */
  margin-bottom: 10px;
  /* Reduzi de 15px para 10px */
  border-bottom: 2px solid #1e3a8a;
  padding-bottom: 4px;
  /* Reduzi pela metade */
  font-weight: 700;
}

/* Listas */
ul {
  padding-left: 20px;
  /* Leve redução */
}

ul li {
  margin-bottom: 6px;
  /* Mais compacto */
  font-size: 1.05rem;
  /* Reduzi um pouco */
}

/* Código */
pre {
  background-color: #f0f4ff;
  color: #1e3a8a;
  padding: 15px;
  /* Reduzi padding */
  border-left: 4px solid #2563eb;
  /* Reduzi espessura da borda */
  border-radius: 8px;
  font-family: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace;
  font-size: 0.95rem;
  /* Leve redução */
  overflow-x: auto;
  box-shadow: 0 2px 6px rgba(37, 99, 235, 0.15);
  line-height: 1.4;
}

code {
  background: none;
  color: inherit;
}

/* Botões */
.button-group {
  display: flex;
  justify-content: center;
  gap: 16px;
  /* Reduzi o espaçamento */
  flex-wrap: wrap;
  margin-top: 30px;
  /* Reduzi */
}

.button-group .btn {
  background-color: #2563eb;
  color: white;
  padding: 12px 24px;
  /* Botões menores */
  border-radius: 12px;
  font-weight: 700;
  font-size: 1rem;
  /* Reduzi */
  box-shadow: 0 4px 10px rgba(37, 99, 235, 0.5);
  transition: background-color 0.3s ease, transform 0.2s ease, box-shadow 0.3s ease;
  user-select: none;
  text-decoration: none;
}

.button-group .btn:hover,
.button-group .btn:focus {
  background-color: #1e40af;
  transform: scale(1.05);
  box-shadow: 0 5px 15px rgba(30, 64, 175, 0.7);
  outline: none;
}

/* Material complementar */
.material-complementar {
  text-align: center;
  margin-top: 30px;
  /* Reduzi */
}

.material-complementar h3 {
  margin-bottom: 15px;
  /* Reduzi */
  color: #1e40af;
  font-weight: 700;
  font-size: 1.3rem;
  /* Reduzi */
}

/* Footer */
footer {
  background-color: #1e293b;
  color: #cbd5e1;
  text-align: center;
  padding: 15px 10px;
  font-size: 0.9rem;
  box-shadow: 0 -3px 6px rgba(30, 41, 59, 0.7);
}