.trace {
  --trace-bg-primary: #f8fafc;
  --trace-bg-secondary: #fff;
  --trace-bg-card: rgba(255, 255, 255, 0.95);
  --trace-border: #e2e8f0;
  --trace-border-active: #0284c7;
  --trace-text-primary: #0f172a;
  --trace-text-muted: #64748b;
  --trace-accent-cyan: #0284c7;
  --trace-accent-amber: #d97706;
  --trace-accent-red: #dc2626;
  --trace-road-asphalt: #334155;
  --trace-grit-color: #475569;
  --trace-rubber-mark: #0f172a;
  --trace-metal-silver: #475569;
  --trace-hud-bg: rgba(255, 255, 255, 0.92);
  --trace-hud-shadow: rgba(0, 0, 0, 0.12);
  --trace-input-bg: #f1f5f9;
  --trace-segmented-bg: #f1f5f9;
  --trace-span: 0.55;
  --trace-tilt: 0deg;

  color: var(--trace-text-primary);
  width: 100%;
  box-sizing: border-box;
}

.theme-dark .trace {
  --trace-bg-primary: #0f172a;
  --trace-bg-secondary: #1e293b;
  --trace-bg-card: rgba(30, 41, 59, 0.85);
  --trace-border: rgba(255, 255, 255, 0.1);
  --trace-border-active: #38bdf8;
  --trace-text-primary: #f8fafc;
  --trace-text-muted: #94a3b8;
  --trace-accent-cyan: #38bdf8;
  --trace-accent-amber: #f59e0b;
  --trace-accent-red: #ef4444;
  --trace-road-asphalt: #334155;
  --trace-grit-color: #475569;
  --trace-rubber-mark: #0f172a;
  --trace-metal-silver: #cbd5e1;
  --trace-hud-bg: rgba(15, 23, 42, 0.88);
  --trace-hud-shadow: rgba(0, 0, 0, 0.6);
  --trace-input-bg: rgba(15, 23, 42, 0.8);
  --trace-segmented-bg: rgba(15, 23, 42, 0.6);
}

.trace * {
  box-sizing: border-box;
}

.trace-card {
  background: var(--trace-bg-primary);
  border: 1px solid var(--trace-border);
  border-radius: 1rem;
  overflow: hidden;
  box-shadow: 0 20px 25px -5px var(--trace-hud-shadow), 0 8px 10px -6px var(--trace-hud-shadow);
  display: flex;
  flex-direction: column;
  gap: 0;
  transition: background-color 0.3s ease, border-color 0.3s ease;
}

.trace-header {
  background: var(--trace-bg-secondary);
  padding: 1.25rem 1.5rem;
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 1.5rem;
  align-items: center;
  border-bottom: 1px solid var(--trace-border);
  transition: background-color 0.3s ease, border-color 0.3s ease;
}

.trace-control-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.trace-label-sm {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--trace-text-muted);
}

.trace-segmented {
  display: inline-flex;
  background: var(--trace-segmented-bg);
  padding: 0.25rem;
  border-radius: 0.6rem;
  border: 1px solid var(--trace-border);
  gap: 0.25rem;
}

.trace-pill {
  border: none;
  background: transparent;
  color: var(--trace-text-muted);
  padding: 0.45rem 0.85rem;
  font-size: 0.85rem;
  font-weight: 500;
  border-radius: 0.45rem;
  cursor: pointer;
  transition: all 0.2s ease;
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.trace-pill:hover {
  color: var(--trace-text-primary);
  background: rgba(0, 0, 0, 0.05);
}

.theme-dark .trace-pill:hover {
  background: rgba(255, 255, 255, 0.05);
}

.trace-pill.is-stencil,
.trace-pill.is-lock {
  background: var(--trace-accent-cyan);
  color: #fff;
  font-weight: 600;
  box-shadow: 0 0 12px rgba(2, 132, 199, 0.3);
}

.theme-dark .trace-pill.is-stencil,
.theme-dark .trace-pill.is-lock {
  color: #0f172a;
  box-shadow: 0 0 12px rgba(56, 189, 248, 0.4);
}

.trace-pill-unit {
  font-size: 0.7rem;
  opacity: 0.85;
  font-weight: 400;
}

.trace-length-group {
  max-width: 220px;
  justify-self: center;
  width: 100%;
}

.trace-length-input-box {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  width: 100%;
}

.trace-input-label {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--trace-text-muted);
}

.trace-input-wrapper {
  display: flex;
  align-items: center;
  background: var(--trace-input-bg);
  border: 1px solid var(--trace-border);
  border-radius: 0.6rem;
  overflow: hidden;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.trace-input-wrapper:focus-within {
  border-color: var(--trace-accent-cyan);
  box-shadow: 0 0 0 3px rgba(2, 132, 199, 0.2);
}

.trace-numeric-input {
  background: transparent;
  border: none;
  color: var(--trace-text-primary);
  padding: 0.5rem 0.75rem;
  font-size: 1.1rem;
  font-weight: 700;
  width: 100%;
  outline: none;
}

.trace-unit-badge {
  background: rgba(0, 0, 0, 0.05);
  color: var(--trace-accent-cyan);
  padding: 0.5rem 0.75rem;
  font-size: 0.85rem;
  font-weight: 600;
}

.theme-dark .trace-unit-badge {
  background: rgba(255, 255, 255, 0.08);
}

.trace-canvas-container {
  position: relative;
  background: #1e293b;
  cursor: ew-resize;
  overflow: hidden;
  user-select: none;
  touch-action: none;
}

.trace-hud-overlay {
  position: absolute;
  top: 1.25rem;
  left: 1.25rem;
  z-index: 10;
  pointer-events: none;
}

.trace-hud-badge {
  background: var(--trace-hud-bg);
  backdrop-filter: blur(12px);
  border: 1px solid var(--trace-border);
  border-radius: 0.75rem;
  padding: 0.85rem 1.25rem;
  box-shadow: 0 10px 25px -5px var(--trace-hud-shadow);
}

.trace-hud-caption {
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--trace-text-muted);
  display: block;
  margin-bottom: 0.2rem;
}

.trace-hud-speed {
  font-size: 2.2rem;
  font-weight: 800;
  color: var(--trace-accent-cyan);
  line-height: 1.1;
  letter-spacing: -0.02em;
}

.trace-hud-range {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--trace-text-muted);
  margin-top: 0.25rem;
}

.trace[data-eval='invalid'] .trace-hud-speed {
  font-size: 1.25rem;
  color: var(--trace-accent-red);
  text-shadow: none;
}

.trace-svg {
  display: block;
  width: 100%;
  height: auto;
  min-height: 260px;
  transform: rotate(var(--trace-tilt));
  transform-origin: center center;
  transition: transform 0.3s ease;
}

.trace-fill-road {
  fill: var(--trace-road-asphalt);
  transition: fill 0.4s ease;
}

.trace-fill-grit {
  fill: var(--trace-grit-color);
}

.trace-lane {
  fill: none;
  stroke: rgba(255, 255, 255, 0.4);
  stroke-width: 5;
  stroke-dasharray: 28 20;
}

.trace-scar-line {
  fill: none;
  stroke: var(--trace-rubber-mark);
  stroke-linecap: round;
  stroke-dasharray: 1;
  stroke-dashoffset: calc(1 - var(--trace-span));
  transition: stroke-dashoffset 0.1s linear, opacity 0.3s ease;
}

.trace-scar-rear {
  stroke-width: 20;
}

.trace-scar-front {
  stroke-width: 12;
}

.trace-stria {
  fill: none;
  stroke: rgba(255, 255, 255, 0.25);
  stroke-width: 2;
  stroke-dasharray: 1;
  stroke-dashoffset: calc(1 - var(--trace-span));
  transition: stroke-dashoffset 0.1s linear;
}

.trace[data-brake='rear'] .trace-scar-front,
.trace[data-brake='front'] .trace-scar-rear {
  opacity: 0.15;
}

.trace[data-brake='unknown'] .trace-scar-line {
  opacity: 0.45;
}

.trace-tyre {
  fill: #090d16;
}

.trace-hub {
  fill: var(--trace-metal-silver);
}

.trace-rotor {
  fill: none;
  stroke: var(--trace-metal-silver);
  stroke-width: 4;
  transition: all 0.3s ease;
}

.trace[data-brake='rear'] .trace-rotor-rear,
.trace[data-brake='both'] .trace-rotor-rear,
.trace[data-brake='front'] .trace-rotor-front,
.trace[data-brake='both'] .trace-rotor-front {
  fill: var(--trace-accent-amber);
  stroke: var(--trace-accent-amber);
}

.trace-swing,
.trace-bars,
.trace-pipe,
.trace-rider {
  fill: none;
  stroke: var(--trace-accent-cyan);
  stroke-width: 4.5;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.trace-body,
.trace-saddle {
  fill: #1e293b;
  stroke: var(--trace-accent-cyan);
  stroke-width: 2;
}

.trace-head {
  fill: var(--trace-accent-cyan);
}

.trace-controls-bottom {
  background: var(--trace-bg-secondary);
  padding: 1.25rem 1.5rem;
  display: grid;
  grid-template-columns: 1fr 340px;
  gap: 1.5rem;
  border-top: 1px solid var(--trace-border);
  transition: background-color 0.3s ease, border-color 0.3s ease;
}

.trace-section-title {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--trace-text-muted);
  margin: 0 0 0.75rem;
}

.trace-surface-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(130px, 1fr));
  gap: 0.5rem;
}

.trace-surface-chip {
  background: var(--trace-segmented-bg);
  border: 1px solid var(--trace-border);
  border-radius: 0.6rem;
  color: var(--trace-text-primary);
  padding: 0.6rem 0.75rem;
  font-size: 0.8rem;
  font-weight: 500;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  transition: all 0.2s ease;
  text-align: left;
}

.trace-surface-chip:hover {
  background: rgba(0, 0, 0, 0.04);
  border-color: var(--trace-text-muted);
}

.theme-dark .trace-surface-chip:hover {
  background: rgba(255, 255, 255, 0.08);
}

.trace-surface-dot {
  width: 0.6rem;
  height: 0.6rem;
  border-radius: 50%;
  background: var(--trace-text-muted);
  flex-shrink: 0;
}

.trace-surface-chip[data-tone='dry'] .trace-surface-dot { background: #64748b; }
.trace-surface-chip[data-tone='wet'] .trace-surface-dot { background: #0284c7; }
.trace-surface-chip[data-tone='concrete'] .trace-surface-dot { background: #94a3b8; }
.trace-surface-chip[data-tone='gravel'] .trace-surface-dot { background: #d97706; }
.trace-surface-chip[data-tone='earth'] .trace-surface-dot { background: #16a34a; }
.trace-surface-chip[data-tone='ice'] .trace-surface-dot { background: #0284c7; }
.trace-surface-chip[data-tone='steel'] .trace-surface-dot { background: #dc2626; }

.trace-surface-chip.is-core {
  border-color: var(--trace-accent-cyan);
  background: rgba(2, 132, 199, 0.1);
  color: var(--trace-accent-cyan);
  font-weight: 600;
  box-shadow: 0 0 10px rgba(2, 132, 199, 0.15);
}

.theme-dark .trace-surface-chip.is-core {
  background: rgba(56, 189, 248, 0.12);
  box-shadow: 0 0 12px rgba(56, 189, 248, 0.2);
}

.trace-sliders-section {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.trace-slider-card {
  background: var(--trace-segmented-bg);
  border: 1px solid var(--trace-border);
  border-radius: 0.6rem;
  padding: 0.75rem 1rem;
}

.trace-slider-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.5rem;
}

.trace-slider-title {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--trace-text-muted);
}

.trace-small-input {
  background: var(--trace-input-bg);
  border: 1px solid var(--trace-border);
  border-radius: 0.4rem;
  color: var(--trace-accent-cyan);
  font-size: 0.85rem;
  font-weight: 700;
  width: 4rem;
  padding: 0.2rem 0.4rem;
  text-align: right;
  outline: none;
}

.trace-small-input:focus {
  border-color: var(--trace-accent-cyan);
}

.trace-slider-val-badge {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--trace-accent-cyan);
}

.trace-range-slider {
  width: 100%;
  height: 6px;
  border-radius: 3px;
  background: var(--trace-border);
  outline: none;
  accent-color: var(--trace-accent-cyan);
  cursor: pointer;
}

/* Dynamic surface environment colors */
.trace[data-surface='wet-asphalt'] .trace-fill-road { fill: #1e293b; }
.trace[data-surface='dry-concrete'] .trace-fill-road { fill: #475569; }
.trace[data-surface='gravel'] .trace-fill-road { fill: #451a03; }
.trace[data-surface='grass'] .trace-fill-road { fill: #064e3b; }
.trace[data-surface='ice'] .trace-fill-road { fill: #1e3a8a; }

@media (max-width: 900px) {
  .trace-header {
    grid-template-columns: 1fr;
    gap: 1rem;
  }

  .trace-length-group {
    max-width: 100%;
  }

  .trace-controls-bottom {
    grid-template-columns: 1fr;
  }
}