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

body {
  font-family: system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
  background: #f4f6f9;
  color: #1a1a2e;
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

nav {
  background: #16213e;
  color: #fff;
  padding: 0.75rem 2rem;
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

nav a { color: #a8d8ea; text-decoration: none; font-weight: 500; }
nav a:hover { color: #fff; }

nav form button {
  background: none; border: 1px solid #a8d8ea; color: #a8d8ea;
  padding: 0.3rem 0.8rem; border-radius: 4px; cursor: pointer;
  font-size: 0.875rem;
}
nav form button:hover { background: #a8d8ea; color: #16213e; }

main {
  flex: 1;
  max-width: 960px;
  width: 100%;
  margin: 2rem auto;
  padding: 0 1rem;
}

h1 { font-size: 1.5rem; margin-bottom: 1rem; color: #16213e; }
h2 { font-size: 1.2rem; margin-bottom: 0.75rem; color: #0f3460; }

p { margin-bottom: 0.75rem; }

a { color: #0f3460; }

form { max-width: 400px; }
label { display: block; margin-bottom: 0.25rem; font-weight: 500; font-size: 0.9rem; }

input[type="email"],
input[type="password"],
input[type="text"] {
  width: 100%; padding: 0.5rem 0.75rem; margin-bottom: 1rem;
  border: 1px solid #ccc; border-radius: 4px; font-size: 1rem;
}

button, .btn {
  background: #0f3460; color: #fff; border: none;
  padding: 0.5rem 1.5rem; border-radius: 4px; font-size: 1rem;
  cursor: pointer;
}
button:hover { background: #16213e; }

pre {
  background: #1a1a2e; color: #e0e0e0; padding: 1rem; border-radius: 4px;
  overflow-x: auto; white-space: pre-wrap; word-break: break-all;
  font-size: 0.875rem;
}

.alert { padding: 1rem; border-radius: 4px; margin-bottom: 1rem; }
.alert-error { background: #fde8e8; border: 1px solid #f5a5a5; color: #a00; }
.alert-success { background: #e8fde8; border: 1px solid #a5f5a5; color: #080; }
.alert-info { background: #e8f0fd; border: 1px solid #a5c5f5; color: #036; }

.locked {
  border: 2px solid #d32f2f; background: #fde8e8; padding: 1rem; border-radius: 4px; margin: 1rem 0;
}
.unlocked {
  border: 2px solid #2e7d32; background: #e8fde8; padding: 1rem; border-radius: 4px; margin: 1rem 0;
}

ul { list-style: none; padding: 0; }
li { margin-bottom: 0.5rem; }

footer {
  text-align: center; padding: 1rem; font-size: 0.8rem; color: #888;
}