:root {
  color-scheme: light dark;
  --bg: #f5f5f4;
  --surface: #ffffff;
  --ink: #1c1917;
  --muted: #57534e;
  --accent: #0f766e;
  --accent-strong: #115e59;
  --error: #b91c1c;
  --error-bg: #fef2f2;
  --ok: #166534;
  --ok-bg: #f0fdf4;
  --border: #d6d3d1;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0c0a09;
    --surface: #1c1917;
    --ink: #f5f5f4;
    --muted: #a8a29e;
    --accent: #2dd4bf;
    --accent-strong: #5eead4;
    --error: #fca5a5;
    --error-bg: #450a0a;
    --ok: #86efac;
    --ok-bg: #052e16;
    --border: #44403c;
  }
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.5 -apple-system, "Segoe UI", Inter, Roboto, sans-serif;
  min-height: 100vh;
}
main {
  max-width: 540px;
  margin: 0 auto;
  padding: 3rem 1.25rem 2rem;
}
header h1 {
  font-size: 1.5rem;
  margin: 0 0 .35rem;
}
.tagline {
  margin: 0 0 2rem;
  color: var(--muted);
  font-size: .95rem;
}
form {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 1.5rem;
  display: grid;
  gap: 1.1rem;
}
.field { display: grid; gap: .35rem; }
label {
  font-weight: 600;
  font-size: .92rem;
  letter-spacing: .01em;
}
select, input[type=file], input[type=password] {
  font: inherit;
  color: var(--ink);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: .55rem .65rem;
}
select:focus, input[type=file]:focus, input[type=password]:focus, button:focus {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}
.muted { color: var(--muted); font-weight: 400; }
small {
  color: var(--muted);
  font-size: .82rem;
}
button {
  font: inherit;
  font-weight: 600;
  background: var(--accent);
  color: white;
  border: 0;
  border-radius: 8px;
  padding: .75rem 1rem;
  cursor: pointer;
  transition: background .15s;
}
button:hover:not(:disabled) { background: var(--accent-strong); }
button:disabled { opacity: .55; cursor: progress; }

.status, .error {
  margin-top: 1.1rem;
  padding: .85rem 1rem;
  border-radius: 8px;
  font-size: .92rem;
  border: 1px solid transparent;
}
.status { background: var(--ok-bg); color: var(--ok); border-color: currentColor; }
.status:empty { display: none; }
.error { background: var(--error-bg); color: var(--error); border-color: currentColor; }

footer {
  margin-top: 2rem;
  color: var(--muted);
  font-size: .8rem;
  line-height: 1.45;
}