:root {
  color-scheme: light dark;
  --accent: #4f7cff;
  --error: #d64545;
  --warn: #b8860b;
  --ok: #2e8b57;
}

* { box-sizing: border-box; }

body {
  font-family: system-ui, -apple-system, sans-serif;
  margin: 0;
  line-height: 1.5;
}

main {
  max-width: 640px;
  margin: 0 auto;
  padding: 2rem 1rem 4rem;
}

h1 { font-size: 1.6rem; }
h2 { font-size: 1.1rem; margin-top: 0; }

.hidden { display: none !important; }
.muted { opacity: 0.7; font-size: 0.85rem; }

.card {
  border: 1px solid rgba(128, 128, 128, 0.35);
  border-radius: 8px;
  padding: 1rem 1.25rem;
  margin: 1rem 0;
}

.banner {
  padding: 0.75rem 1rem;
  border-radius: 8px;
  margin: 1rem 0;
}
.banner.error { background: rgba(214, 69, 69, 0.15); border: 1px solid var(--error); }

.field { margin: 1rem 0; }
.field label { display: block; font-weight: 600; margin-bottom: 0.25rem; }
.field label .required-marker { color: var(--error); margin-left: 0.2rem; font-weight: 700; }
.field label .optional-marker { color: inherit; opacity: 0.6; font-weight: 400; font-size: 0.85rem; }
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}
.field .help { font-size: 0.85rem; opacity: 0.7; margin: 0 0 0.25rem; }

select option {
  background: Canvas;
  color: CanvasText;
}

input[type="text"], input[type="number"], textarea, select {
  width: 100%;
  padding: 0.5rem 0.6rem;
  border: 1px solid rgba(128, 128, 128, 0.5);
  border-radius: 6px;
  font: inherit;
  background: transparent;
}

.field-error { color: var(--error); font-size: 0.85rem; margin-top: 0.25rem; }

.warnings { margin-top: 0.5rem; }
.warnings p { color: var(--warn); font-size: 0.85rem; margin: 0.2rem 0; }

button {
  background: var(--accent);
  color: white;
  border: 0;
  border-radius: 6px;
  padding: 0.6rem 1.4rem;
  font: inherit;
  font-weight: 600;
  cursor: pointer;
}
button:disabled { opacity: 0.5; cursor: default; }

.progress-track {
  height: 10px;
  border-radius: 5px;
  background: rgba(128, 128, 128, 0.25);
  overflow: hidden;
}
.progress-bar {
  height: 100%;
  width: 0;
  background: var(--accent);
  transition: width 0.2s;
}

#result.ok { border-color: var(--ok); }
#result.error { border-color: var(--error); }
#result ul { margin: 0.5rem 0 0; padding-left: 1.2rem; }
#result li { color: var(--error); }