:root {
  --bg: #0a0d10; --surface: #11171c; --border: #2a363e; --text: #e6edf0;
  --muted: #a8b5bd; --accent: #4cc38a; --on-accent: #0a0d10; --danger: #f06b6b;
  color-scheme: dark;
}
:root[data-theme="light"] {
  --bg: #f4f6f8; --surface: #ffffff; --border: #c9d2d8; --text: #12181d;
  --muted: #4a5861; --accent: #1f8f5c; --on-accent: #ffffff; --danger: #b42323;
  color-scheme: light;
}
* { box-sizing: border-box; }
body {
  margin: 0; min-height: 100vh; display: grid; place-items: center; padding: 16px;
  background: var(--bg); color: var(--text);
  font: 400 15px/1.5 "IBM Plex Sans", system-ui, sans-serif;
}
.panel {
  width: 100%; max-width: 380px; padding: 20px;
  background: var(--surface); border: 1px solid var(--border); border-radius: 8px;
}
.brand {
  display: flex; align-items: center; gap: 8px; padding: 0; margin: 0 0 16px;
  background: none; border: 0; color: var(--text); font: inherit; font-weight: 650; cursor: default;
}
h1 { margin: 0 0 8px; font-size: 22px; font-weight: 650; }
p { margin: 0 0 16px; color: var(--muted); }
label { display: block; margin: 0 0 4px; font-size: 13px; color: var(--muted); }
input {
  width: 100%; padding: 10px; margin: 0 0 16px; font: inherit; color: var(--text);
  background: var(--bg); border: 1px solid var(--border); border-radius: 6px;
}
input:focus-visible, button:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.error { color: var(--danger); margin: 0 0 16px; }
#submit {
  width: 100%; padding: 10px; font: inherit; font-weight: 600; cursor: pointer;
  background: var(--accent); color: var(--on-accent); border: 0; border-radius: 6px;
}
#submit:disabled { opacity: 0.6; cursor: default; }
a { color: var(--accent); }