:root {
  --bg: #0f172a;
  --surface: #111827;
  --surface-soft: #1f2937;
  --text: #e5e7eb;
  --muted: #94a3b8;
  --primary: #22d3ee;
  --border: #334155;
  --danger: #f87171;
}

body.light {
  --bg: #f8fafc;
  --surface: #ffffff;
  --surface-soft: #f1f5f9;
  --text: #0f172a;
  --muted: #475569;
  --primary: #0891b2;
  --border: #cbd5e1;
  --danger: #dc2626;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  background: radial-gradient(circle at top, #1e293b, var(--bg));
  color: var(--text);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
}
.app { max-width: 1100px; margin: 0 auto; padding: 24px; }
.topbar { display: flex; justify-content: space-between; align-items: center; gap: 16px; margin-bottom: 20px; }
.card { background: var(--surface); border: 1px solid var(--border); border-radius: 16px; padding: 20px; }
.card h2 { margin: 0 0 8px; font-size: 18px; }
.muted { color: var(--muted); margin: 0 0 12px; font-size: 14px; }
.btn {
  border: 1px solid transparent;
  background: var(--primary);
  color: #001018;
  padding: 10px 14px;
  border-radius: 10px;
  font-weight: 600;
  cursor: pointer;
}
.btn.ghost { background: transparent; color: var(--text); border-color: var(--border); }
.btn:disabled { opacity: .5; cursor: not-allowed; }
input[type="file"], select { width: 100%; margin-bottom: 10px; padding: 10px; background: var(--surface-soft); color: var(--text); border: 1px solid var(--border); border-radius: 10px; }
.status { min-height: 20px; margin: 8px 0 0; color: var(--muted); font-size: 14px; }
.error { color: var(--danger); }
.ok { color: #34d399; }
.mapping-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.preview { max-height: 180px; overflow: auto; border: 1px solid var(--border); border-radius: 10px; padding: 8px; background: var(--surface-soft); font-size: 12px; }
.preview table { width: 100%; border-collapse: collapse; }
.preview td, .preview th { border-bottom: 1px solid var(--border); padding: 4px; text-align: left; }
.result img { width: 100%; border-radius: 12px; border: 1px solid var(--border); background: #fff; }
.kpi { display: flex; gap: 8px; flex-wrap: wrap; margin: 10px 0; }
.tag { padding: 6px 8px; border-radius: 999px; background: var(--surface-soft); border: 1px solid var(--border); font-size: 12px; }
.hero {
  min-height: 62vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.stepper {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
  margin-bottom: 16px;
}

.step {
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--muted);
  border-radius: 12px;
  padding: 10px 12px;
  text-align: left;
  font-weight: 600;
  cursor: pointer;
}

.step.is-active {
  color: var(--text);
  border-color: var(--primary);
  box-shadow: 0 0 0 2px color-mix(in srgb, var(--primary) 25%, transparent);
}

.step.is-complete {
  color: #34d399;
}

.screen {
  display: none;
  opacity: 0;
  transform: translateY(12px);
}

.screen.is-active {
  display: block;
  animation: fadeSlide 280ms ease forwards;
}

.dropzone {
  display: block;
  border: 1.5px dashed var(--border);
  border-radius: 14px;
  background: var(--surface-soft);
  padding: 22px;
  margin-bottom: 12px;
  cursor: pointer;
  transition: border-color 0.2s ease, transform 0.2s ease;
}

.dropzone:hover {
  border-color: var(--primary);
  transform: translateY(-1px);
}

.dropzone-title {
  display: block;
  font-weight: 600;
  margin-bottom: 4px;
}

.dropzone-subtitle {
  display: block;
  color: var(--muted);
  font-size: 13px;
}

.dropzone input[type="file"] {
  margin-top: 12px;
}

.visually-hidden {
  position: absolute !important;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.selected-file {
  display: block;
  margin-top: 10px;
  font-size: 13px;
  color: var(--text);
  opacity: 0.9;
}

.actions {
  display: flex;
  gap: 8px;
  margin-top: 12px;
}

.summary-card {
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 12px;
  background: var(--surface-soft);
}

.engine-indicator {
  display: inline-flex;
  align-items: center;
  font-weight: 700;
  border-radius: 999px;
  padding: 8px 12px;
  margin-bottom: 10px;
  border: 1px solid var(--border);
}

.engine-indicator.ok {
  background: color-mix(in srgb, #34d399 25%, var(--surface-soft));
  color: #065f46;
}

.engine-indicator.warn {
  background: color-mix(in srgb, #ff8c00 26%, var(--surface-soft));
  color: #9a3412;
}

.cylinder-view {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 10px;
  margin: 12px 0;
}

.cylinder-card {
  border: 1px solid var(--border);
  background: var(--surface-soft);
  border-radius: 14px;
  padding: 10px;
}

.cylinder-card h4 {
  margin: 0 0 8px;
  font-size: 13px;
  color: var(--muted);
}

.cylinder-shell {
  height: 340px;
  border-radius: 34px;
  border: 1px solid var(--border);
  background: linear-gradient(180deg, #e2e8f0 0%, #94a3b8 100%);
  position: relative;
  overflow: hidden;
}

.cylinder-plot {
  position: absolute;
  inset: 8px;
  border-radius: 24px;
  background: color-mix(in srgb, #ffffff 16%, transparent);
}

.box-whisker {
  position: absolute;
  width: 2px;
  left: 50%;
  transform: translateX(-50%);
  background: #0f172a;
}

.box-cap {
  position: absolute;
  left: 24%;
  width: 52%;
  height: 2px;
  background: #0f172a;
}

.box-zero-axis {
  position: absolute;
  left: 8%;
  width: 84%;
  height: 2px;
  border-radius: 999px;
  background: rgba(15, 23, 42, 0.55);
}

.box-body {
  position: absolute;
  left: 16%;
  width: 68%;
  border-radius: 14px;
  border: 2px solid #0f172a;
  background: linear-gradient(180deg, #0ea5e9, #0284c7);
}

.box-body.warn {
  background: linear-gradient(180deg, #fb923c, #f97316);
}

@keyframes fadeSlide {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 720px) {
  .app { padding: 14px; }
  .stepper { grid-template-columns: 1fr; }
  .mapping-grid { grid-template-columns: 1fr; }
}