:root {
  --bg: #f9f9f9;
  --text: #222;
  --accent: #005b96;
  --error: #b00020;
  --border: #ccc;
  --card-bg: #fff;
}

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

header {
  background: var(--accent);
  color: white;
  padding: 1rem;
  text-align: center;
}

nav {
  margin-top: 0.5rem;
}

nav a {
  color: white;
  margin: 0 0.75rem;
  text-decoration: none;
  font-weight: bold;
}

main {
  max-width: 700px;
  margin: 2rem auto;
  padding: 0 1rem;
}

footer {
  text-align: center;
  font-size: 0.9rem;
  padding: 1rem;
  border-top: 1px solid var(--border);
  color: #555;
}

form {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

input[type="text"],
input[type="password"],
input[type="number"],
select,
textarea {
  padding: 0.5rem;
  font-size: 1rem;
  border: 1px solid var(--border);
  border-radius: 4px;
}

button {
  background-color: var(--accent);
  color: white;
  border: none;
  padding: 0.6rem 1.2rem;
  font-size: 1rem;
  cursor: pointer;
  border-radius: 4px;
}

button:hover {
  opacity: 0.9;
}

label {
  font-weight: bold;
}

.error {
  color: var(--error);
  font-size: 0.9rem;
}

.auth-container {
  max-width: 400px;
  margin: 2rem auto;
  padding: 2rem;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 6px;
}

.editor {
  min-height: 200px;
  border: 1px solid var(--border);
  padding: 1rem;
  background: #fff;
  white-space: pre-wrap;
  overflow-y: auto;
}

.reader-content {
  background: #fff;
  border: 1px solid var(--border);
  padding: 1rem;
  white-space: pre-wrap;
  min-height: 150px;
}

#chapter-controls {
  margin-top: 1rem;
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

@media (max-width: 600px) {
  header h1 {
    font-size: 1.5rem;
  }

  nav a {
    display: block;
    margin: 0.3rem 0;
  }

  main {
    padding: 1rem;
  }

  .auth-container {
    margin: 1rem;
    padding: 1rem;
  }
}