:root {
  --bg: #0f172a;
  --panel: #1e293b;
  --panel-2: #273449;
  --text: #e2e8f0;
  --muted: #94a3b8;
  --accent: #38bdf8;
  --accent-2: #0ea5e9;
  --err: #f87171;
  --ok: #4ade80;
  --border: #334155;
  --radius: 12px;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
}

.app {
  max-width: 920px;
  margin: 0 auto;
  padding: 2rem 1.25rem 3rem;
}

.app__header h1 {
  margin: 0 0 .25rem;
  font-size: 1.6rem;
}

.app__sub {
  margin: 0 0 1.5rem;
  color: var(--muted);
  max-width: 60ch;
}

.layout {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 1.5rem;
  align-items: start;
}

@media (max-width: 720px) {
  .layout { grid-template-columns: 1fr; }
}

.form, .result {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
}

.field {
  display: block;
  margin-bottom: 1rem;
  border: 0;
  padding: 0;
}

.field--radio { margin-bottom: 1rem; }

.field__label {
  display: block;
  font-weight: 600;
  font-size: .9rem;
  margin-bottom: .35rem;
}

.req { color: var(--accent); }
.opt { color: var(--muted); font-weight: 400; font-size: .8rem; }

input[type="text"] {
  width: 100%;
  padding: .6rem .7rem;
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text);
  font-size: 1rem;
  font-family: inherit;
}

input[type="text"]:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 2px rgba(56, 189, 248, .25);
}

input.invalid { border-color: var(--err); }
input.valid { border-color: var(--ok); }

.field__hint {
  display: block;
  min-height: 1.1em;
  margin-top: .3rem;
  font-size: .8rem;
  color: var(--muted);
}
.field__hint.error { color: var(--err); }

.radios {
  display: flex;
  gap: 1rem;
  margin-bottom: .5rem;
  flex-wrap: wrap;
}
.radio {
  font-size: .9rem;
  font-weight: 400;
  display: flex;
  align-items: center;
  gap: .35rem;
  cursor: pointer;
}

.btn {
  appearance: none;
  border: 0;
  background: var(--accent-2);
  color: #04293b;
  font-weight: 600;
  font-size: .95rem;
  padding: .6rem 1rem;
  border-radius: 8px;
  cursor: pointer;
}
.btn:hover { background: var(--accent); }
.btn:disabled { opacity: .45; cursor: not-allowed; }

.btn--ghost {
  background: transparent;
  color: var(--muted);
  border: 1px solid var(--border);
}
.btn--ghost:hover { background: var(--panel-2); color: var(--text); }

.result { text-align: center; position: sticky; top: 1rem; }

.qr {
  background: #fff;
  border-radius: 8px;
  padding: 12px;
  width: 100%;
  aspect-ratio: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: .75rem;
}
.qr img, .qr canvas { width: 100%; height: auto; image-rendering: pixelated; }
.qr.empty {
  background: var(--panel-2);
  color: var(--muted);
  font-size: .85rem;
  padding: 1rem;
}

.status {
  min-height: 1.2em;
  margin: 0 0 .75rem;
  font-size: .85rem;
  color: var(--muted);
}
.status.error { color: var(--err); }
.status.ok { color: var(--ok); }

.payload {
  text-align: left;
  margin-top: 1rem;
  font-size: .8rem;
}
.payload summary { cursor: pointer; color: var(--muted); }
.payload pre {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: .6rem;
  overflow-x: auto;
  white-space: pre-wrap;
  word-break: break-all;
  color: var(--text);
}

.app__footer {
  margin-top: 2rem;
  color: var(--muted);
  font-size: .8rem;
  text-align: center;
}