:root { --bg: #f5f6f8; --card: #fff; --text: #15181c; --muted: #64707d; --line: #e2e6ea; --accent: #1d9bf0; --bad: #d64545; }
@media (prefers-color-scheme: dark) {
  :root { --bg: #0f1216; --card: #171b21; --text: #e7eaee; --muted: #8b96a3; --line: #262c34; --accent: #4cb3f5; --bad: #ff6b6b; }
}
* { box-sizing: border-box; }
body {
  margin: 0; min-height: 100vh; display: flex; align-items: center; justify-content: center;
  background: var(--bg); color: var(--text); padding: 16px;
  font: 15px/1.45 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}
.box { width: 100%; max-width: 340px; background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 24px; }
h1 { margin: 0 0 16px; font-size: 20px; }
form { display: flex; flex-direction: column; gap: 10px; }
label { color: var(--muted); font-size: 13px; }
input {
  font: inherit; color: var(--text); background: var(--bg); border: 1px solid var(--line);
  border-radius: 8px; padding: 10px 12px;
}
button {
  font: inherit; font-weight: 600; color: #fff; background: var(--accent); border: 0;
  border-radius: 8px; padding: 10px 12px; cursor: pointer;
}
.msg { display: none; margin: 12px 0 0; color: var(--bad); font-size: 13px; }