:root {
  --bg: #f0f4f8;
  --text: #1b5e20;
  --card: #ffffff;
  --res: #e8f5e9;
  --shadow: rgba(0, 0, 0, 0.05);
}

.dark-mode {
  --bg: #121212;
  --text: #ffffff;
  --card: #1e1e1e;
  --res: #2e7d32;
  --shadow: rgba(255, 255, 255, 0.05);
}

body {
  margin: 0;
  padding: 0;
  background-color: var(--bg);
  font-family: 'Poppins', sans-serif;
  color: var(--text);
  transition: background-color 0.3s ease, color 0.3s ease;
}

.container {
  max-width: 800px;
  width: 100%;
  margin: auto;
  padding: 20px;
}

h1, h2 {
  color: var(--text);
}

.card {
  background-color: var(--card);
  border-radius: 12px;
  padding: 25px;
  margin-bottom: 30px;
  box-shadow: 0 6px 15px var(--shadow);
}

textarea,
input {
  width: 100%;
  padding: 12px;
  margin-top: 8px;
  margin-bottom: 16px;
  font-size: 16px;
  border-radius: 8px;
  border: 1px solid #ccc;
  box-sizing: border-box;
  background-color: #fff;
  color: #000;
}

.dark-mode textarea,
.dark-mode input {
  background-color: #1e1e1e;
  color: #fff;
  border: 1px solid #555;
}

button {
  padding: 12px 24px;
  font-size: 16px;
  background: linear-gradient(90deg, #4CAF50, #2E7D32);
  color: white;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.3s ease, transform 0.2s ease;
}

button:hover {
  background: linear-gradient(90deg, #66BB6A, #388E3C);
  transform: scale(1.03);
}

.resultado {
  margin-top: 15px;
  background: var(--res);
  padding: 10px;
  border-left: 4px solid #388E3C;
  border-radius: 6px;
  white-space: pre-line;
  font-size: 16px;
  color: var(--text);
}

canvas {
  margin-top: 20px;
  background: #fff;
  border-radius: 12px;
  padding: 10px;
}

.dark-mode canvas {
  background: #2e2e2e;
}

.voltar-btn {
  display: inline-block;
  margin: 20px 0;
  padding: 12px 24px;
  background-color: #4CAF50;
  color: white;
  border-radius: 8px;
  text-decoration: none;
  font-weight: bold;
  font-size: 16px;
  transition: background 0.3s ease, transform 0.2s ease;
}

.voltar-btn:hover {
  background-color: #388E3C;
  transform: scale(1.05);
}

.titulo-gerador {
  color: #FFD600; /* amarelo escuro (mais vibrante que fdd835) */
  font-weight: bold;
  text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.7);
  display: inline-block;
}

@media (max-width: 768px) {
  body {
    font-size: 15px;
    background-attachment: scroll; /* evita problemas em mobile com imagens fixas */
  }

  .login-container {
    padding: 15px;
  }

  .login-box {
    padding: 20px;
    max-width: 90%;
  }

  .titulo-gerador {
    font-size: 20px;
    text-align: center;
    display: block;
    margin-top: 10px;
  }

  nav {
    flex-direction: column;
    gap: 6px;
    padding: 10px;
  }

  textarea,
  input {
    font-size: 14px;
    padding: 10px;
  }

  button {
    font-size: 14px;
    padding: 10px 16px;
  }

  .card {
    padding: 18px;
  }

  canvas {
    width: 100% !important;
    height: auto !important;
  }

  .opcoes-navegacao a {
    display: block;
    width: 100%;
    margin: 8px 0;
    padding: 10px;
    font-size: 14px;
  }
}