:root {
  color-scheme: light dark;

  --bg: #f5f5f7;
  --bg-elevated: #ffffff;
  --text: #1c1c1e;
  --text-muted: #6b6b70;
  --border: rgba(0, 0, 0, 0.1);
  --accent: #007aff;
  --accent-text: #ffffff;
  --success: #248a3d;
  --success-bg: rgba(52, 199, 89, 0.14);
  --danger: #d70015;
  --danger-bg: rgba(255, 59, 48, 0.12);
  --warning: #a05a00;
  --warning-bg: rgba(255, 149, 0, 0.14);
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.06), 0 8px 24px rgba(0, 0, 0, 0.06);
  --radius: 16px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #000000;
    --bg-elevated: #1c1c1e;
    --text: #f5f5f7;
    --text-muted: #9a9aa0;
    --border: rgba(255, 255, 255, 0.12);
    --accent: #0a84ff;
    --success: #30d158;
    --success-bg: rgba(48, 209, 88, 0.16);
    --danger: #ff453a;
    --danger-bg: rgba(255, 69, 58, 0.16);
    --warning: #ff9f0a;
    --warning-bg: rgba(255, 159, 10, 0.16);
    --shadow: none;
  }
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 0 20px 48px;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.5 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  -webkit-font-smoothing: antialiased;
}

.app {
  max-width: 620px;
  margin: 0 auto;
}

/* - - - hero - - - */

.hero {
  text-align: center;
  padding: 48px 0 32px;
}

.hero__robot {
  width: 104px;
  height: auto;
  animation: float 4s ease-in-out infinite;
}

@keyframes float {
  0%,
  100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-8px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .hero__robot {
    animation: none;
  }
}

.hero h1 {
  margin: 16px 0 6px;
  font-size: 30px;
  letter-spacing: -0.02em;
}

.hero__subtitle {
  margin: 0;
  color: var(--text-muted);
}

/* - - - cards & steps - - - */

.card {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 20px;
  margin-bottom: 16px;
}

.step {
  display: flex;
  align-items: center;
  gap: 10px;
}

.step__number {
  display: grid;
  place-items: center;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--accent);
  color: var(--accent-text);
  font-size: 13px;
  font-weight: 600;
  flex: none;
}

.step__title {
  margin: 0;
  font-size: 17px;
  font-weight: 600;
}

.step__hint {
  margin: 10px 0 16px;
  color: var(--text-muted);
  font-size: 14px;
}

.step__hint:last-child {
  margin-bottom: 0;
}

code {
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 0.9em;
  background: var(--border);
  border-radius: 5px;
  padding: 1px 5px;
}

/* - - - controls - - - */

.row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
}

.button {
  appearance: none;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: transparent;
  color: var(--text);
  font: inherit;
  font-weight: 500;
  padding: 10px 18px;
  cursor: pointer;
  transition: opacity 0.15s ease, transform 0.1s ease;
}

.button:hover:not(:disabled) {
  opacity: 0.8;
}

.button:active:not(:disabled) {
  transform: scale(0.98);
}

.button:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.button--primary {
  background: var(--accent);
  border-color: transparent;
  color: var(--accent-text);
}

.button--danger {
  color: var(--danger);
  border-color: var(--danger);
}

.pill {
  font-size: 13px;
  font-weight: 500;
  padding: 5px 12px;
  border-radius: 999px;
  background: var(--border);
  color: var(--text-muted);
}

.pill--live {
  background: var(--success-bg);
  color: var(--success);
}

/* - - - robot info - - - */

.info {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 12px;
  margin: 18px 0 0;
  padding-top: 18px;
  border-top: 1px solid var(--border);
}

.info__item dt {
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-muted);
}

.info__item dd {
  margin: 4px 0 0;
  font-size: 16px;
  font-weight: 600;
}

/* - - - firmware choice - - - */

.choices {
  display: grid;
  gap: 10px;
  margin-top: 16px;
}

.choice {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 14px;
  border: 1px solid var(--border);
  border-radius: 12px;
  cursor: pointer;
}

.choice:has(input:checked) {
  border-color: var(--accent);
  background: color-mix(in srgb, var(--accent) 7%, transparent);
}

.choice input {
  margin: 2px 0 0;
  accent-color: var(--accent);
  flex: none;
}

.choice__body {
  display: grid;
  gap: 3px;
}

.choice__title {
  font-weight: 500;
}

.choice__detail {
  font-size: 13px;
  color: var(--text-muted);
}

/* - - - progress - - - */

.progress {
  margin-top: 20px;
}

.progress__track {
  height: 8px;
  border-radius: 999px;
  background: var(--border);
  overflow: hidden;
}

.progress__bar {
  height: 100%;
  border-radius: 999px;
  background: var(--accent);
  transition: width 0.2s ease;
}

.progress__bar--done {
  background: var(--success);
}

.progress__labels {
  display: flex;
  justify-content: space-between;
  margin-top: 8px;
  font-size: 13px;
  color: var(--text-muted);
  font-variant-numeric: tabular-nums;
}

/* - - - banners & log - - - */

.banner {
  margin: 16px 0 0;
  padding: 12px 14px;
  border-radius: 12px;
  font-size: 14px;
  background: var(--border);
}

.banner--success {
  background: var(--success-bg);
  color: var(--success);
}

.banner--error {
  background: var(--danger-bg);
  color: var(--danger);
}

.banner--warning {
  background: var(--warning-bg);
  color: var(--warning);
}

.log-panel {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px 16px;
  color: var(--text-muted);
  font-size: 14px;
}

.log-panel summary {
  cursor: pointer;
}

.log {
  max-height: 220px;
  overflow: auto;
  margin: 12px 0 0;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 12px;
  line-height: 1.6;
  white-space: pre-wrap;
  word-break: break-word;
}

.footer {
  margin-top: 24px;
  text-align: center;
  font-size: 13px;
  color: var(--text-muted);
}