*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --bg: #0f0f0f;
  --surface: #1a1a1a;
  --border: rgba(255, 255, 255, 0.08);
  --text: #ffffff;
  --muted: rgba(255, 255, 255, 0.45);
  --accent: #ff6b35;
}

html, body {
  height: 100%;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
  user-select: none;
  overflow: hidden;
}

.back-link {
  position: fixed;
  top: 1.2rem;
  left: 1.5rem;
  font-size: 0.65rem;
  font-weight: 600;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--muted);
  text-decoration: none;
  transition: color 0.2s ease;
  z-index: 10;
}

.back-link:hover {
  color: var(--text);
}

#install-btn {
  position: fixed;
  top: 1.2rem;
  right: 1.5rem;
  background: transparent;
  border: none;
  cursor: pointer;
  font-size: 0.65rem;
  font-weight: 600;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--muted);
  padding: 0;
  z-index: 10;
  transition: color 0.2s ease;
  -webkit-tap-highlight-color: transparent;
}

#install-btn:hover {
  color: var(--text);
}

html, body {
  overflow: auto;
}

main {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.25rem;
  padding: 4.5rem 1.25rem 2rem;
  min-height: 100%;
}

h1 {
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
}

#qr-input {
  width: 100%;
  max-width: 400px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text);
  font-family: inherit;
  font-size: 1rem;
  line-height: 1.5;
  padding: 0.75rem 1rem;
  resize: vertical;
  outline: none;
  user-select: text;
  transition: border-color 0.2s;
}

#qr-input:focus {
  border-color: var(--accent);
}

#qr-input::placeholder {
  color: var(--muted);
}

.controls {
  display: flex;
  align-items: center;
  gap: 1rem;
  width: 100%;
  max-width: 400px;
  flex-wrap: wrap;
}

fieldset {
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.35rem 0.75rem;
  display: flex;
  align-items: center;
  gap: 0.1rem;
  flex: 1;
}

legend {
  font-size: 0.6rem;
  font-weight: 600;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--muted);
  padding: 0 0.25rem;
}

fieldset label {
  display: flex;
  align-items: center;
  gap: 0.3rem;
  font-size: 0.85rem;
  color: var(--muted);
  cursor: pointer;
  padding: 0.2rem 0.4rem;
  border-radius: 4px;
  transition: color 0.15s;
  user-select: none;
}

fieldset label:has(input:checked) {
  color: var(--accent);
}

fieldset input[type="radio"] {
  accent-color: var(--accent);
}

#download-btn {
  background: var(--accent);
  border: none;
  border-radius: 6px;
  color: #0f0f0f;
  cursor: pointer;
  font-family: inherit;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 0.6rem 1.1rem;
  transition: opacity 0.2s;
  white-space: nowrap;
  flex-shrink: 0;
}

#download-btn:disabled {
  opacity: 0.3;
  cursor: default;
}

#download-btn:not(:disabled):hover {
  opacity: 0.85;
}

#qr-output {
  background: #ffffff;
  border-radius: 10px;
  padding: 16px;
  display: none;
}

#qr-output canvas,
#qr-output img {
  display: block;
}

#qr-empty {
  font-size: 0.85rem;
  color: var(--muted);
  text-align: center;
}