body { font-family: sans-serif; background: #121212; color: white; display: flex; justify-content: center; padding: 20px; }
#auth-container, #app-container { width: 100%; max-width: 400px; }
input, textarea { width: 100%; padding: 10px; margin: 10px 0; border-radius: 4px; border: 1px solid #333; background: #222; color: white; box-sizing: border-box; }
button { padding: 10px 20px; cursor: pointer; background: #3d5afe; color: white; border: none; border-radius: 4px; }
button:hover { background: #536dfe; }
.note-card { background: #1e1e1e; padding: 15px; margin-bottom: 10px; border-radius: 8px; border-left: 4px solid #3d5afe; }
.note-card h3 { margin-top: 0; }