/* Reset + root variables */

:root {
  --navy: #2c3e50;
  --softgray: #ecf0f1;
  --teal: #1abc9c;
  --gold: #f1c40f;
  --slate: #7f8c8d;
  --coral: #e74c3c;
  --white: #ffffff;
  --gray-100: #f7fafc;
  --gray-200: #edf2f7;
  --gray-300: #e2e8f0;
  --max-width: 1200px;
  --container-pad: 16px;
  --radius: 10px;
  --shadow-sm: 0 6px 18px rgba(0, 0, 0, 0.06);
  --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.06);
  --road-top: #64748b;
  --road-bottom: #94a3b8;
  --thinking-color: rgba(234, 179, 8, 0.5);
  --braking-color: rgba(239, 68, 68, 0.5);
}

* {
  box-sizing: border-box;
}

html,
body {
  height: 100%;
}

/* Page base */
body {
  margin: 0;
  font-family:
    'Montserrat',
    system-ui,
    -apple-system,
    'Segoe UI',
    Roboto,
    'Helvetica Neue',
    Arial;
  color: var(--navy);
  background: linear-gradient(135deg, #ecf0f1 0%, #d6dbdf 100%);
  padding: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

li {
  line-height: 2;
}

.header h1 {
  margin: 0;
  font-size: 2rem;
  font-weight: 600;
  font-family: 'Montserrat', sans-serif;
}

/* Layout */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  gap: 18px;
  padding: 18px;
}

.header-left {
  justify-self: start;
}

.page-header {
  text-align: center;
  color: var(--navy);
  padding: 1rem;
  position: relative;
}

.header-grid {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 12px;
  padding: 8px 0;
}

.page-title {
  margin: 0;
  justify-self: center;
  font-size: clamp(1.25rem, 3vw, 2rem);
  font-weight: 700;
  font-family: 'Montserrat', sans-serif;
}

.header-actions {
  justify-self: end;
}

/* mobile: stack nicely */
@media (max-width: 767px) {
  .header-grid {
    grid-template-columns: 1fr;
    /* stack everything */
    grid-auto-flow: row;
    text-align: left;
  }

  .page-title {
    justify-self: start;
  }

  .header-actions {
    justify-self: start;
    width: 100%;
    margin-top: 8px;
  }
}

.cols {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

/* main layout */
.main {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

/* Card */
.card {
  background: var(--white);
  border-radius: 12px;
  box-shadow: 0 8px 24px rgba(44, 62, 80, 0.06);
  padding: 0;
  overflow: visible;
}

.card-inner {
  padding: 18px;
}

.card-title {
  font-size: 1.2rem;
  margin-bottom: 8px;
  color: var(--navy);
}

/* text */
.muted {
  color: var(--slate);
  font-size: 1rem;
  margin-bottom: 10px;
}

/* reaction area */
.reaction-area-wrap {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.reaction-test-area {
  height: 160px;
  border-radius: 10px;
  background: var(--gray-200);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-weight: 600;
  color: var(--navy);
  transition:
    background-color 0.12s ease,
    transform 0.08s ease;
  touch-action: manipulation;
}

/* controls row */
.controls-row {
  display: flex;
  gap: 12px;
  align-items: center;
  flex-wrap: wrap;
}

/* generic button */
.btn {
  display: inline-block;
  padding: 0.5rem 1rem;
  border-radius: 0.375rem;
  font-weight: 500;
  text-decoration: none;
  text-align: center;
  transition: all 0.2s;
  cursor: pointer;
  border: 1px solid transparent;
  width: auto;
  font-size: 16px;
  font-weight: 600;
  padding: 12px 24px;
}

.btn:active {
  transform: translateY(1px);
}

/* button variants */
.teal-btn {
  background: rgba(26, 188, 156, 0.9);
  color: var(--white);
}

.teal-btn:hover {
  background: rgba(26, 188, 156, 0.8);
  transform: translateY(-10%);
  opacity: 0.98;
}

.gold-btn {
  background: rgba(241, 196, 15, 0.9);
  color: var(--navy);
}

.gold-btn:hover {
  background: rgba(241, 196, 15, 0.8);
  transform: translateY(-10%);
  opacity: 0.98;
}

.navy-btn {
  background: rgba(44, 62, 80, 0.9);
  color: var(--white);
}

.navy-btn:hover {
  background: rgba(44, 62, 80, 0.8);
  transform: translateY(-10%);
  opacity: 0.98;
}

.coral-btn {
  background-color: rgba(231, 76, 60, 0.8);
  color: white;
}

.coral-btn:hover {
  background-color: rgba(231, 76, 60, 0.7);
  transform: translateY(-10%);
  opacity: 0.98;
}

/* road & visuals */
.road-wrap {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.road {
  background: var(--road-bottom);

  position: relative;
  overflow: hidden;
  height: clamp(120px, 20vw, 160px);
  border-radius: 10px;
}

/* stripes */
.road-markings {
  position: absolute;
  top: 50%;
  left: 0;
  right: 0;
  height: 4px;
  background: repeating-linear-gradient(
    to right,
    #ffffff,
    #ffffff 20px,
    transparent 20px,
    transparent 40px
  );
  width: 200%;
}

/* car & hazard */

.car {
  position: absolute;
  /* we'll set .left in JS to a px value (centered). */
  /* vertically center the SVG inside the road */
  top: 50%;
  transform: translateY(-50%);
  z-index: 20;
  transition: left 0.2s linear;
}

/* make the SVG bigger inside the .car container */
.car svg {
  width: 140px;
  /* bigger car — tweak as desired */
  height: auto;
  display: block;
  pointer-events: none;
}

.hazard {
  position: absolute;
  bottom: 6px;
  z-index: 20;
  transition: opacity 0.35s ease;
}

/* distance visuals */
.distance-marker {
  position: absolute;
  bottom: 0;
  width: 2px;
  height: 100%;
  opacity: 0;
  transition: opacity 0.35s ease;
}

.distance-label {
  position: absolute;
  top: -28px;
  transform: translateX(-50%);
  padding: 6px 10px;
  border-radius: 8px;
  font-size: 12px;
  font-weight: 600;
  background: var(--white);
  color: var(--navy);
  box-shadow: 0 8px 18px rgba(44, 62, 80, 0.06);
  white-space: nowrap;
}

.thinking-distance,
.braking-distance {
  position: absolute;
  top: 0;
  /* start at the top of the road container */
  height: 100%;
  /* fill whole height of the road */
  opacity: 0;
  transition:
    opacity 0.35s ease,
    width 0.2s ease,
    left 0.2s ease;
  z-index: 5;
  /* behind car and hazard */
}

.thinking-distance {
  background: var(--thinking-color);
  border-radius: 0;
}

.braking-distance {
  background: var(--braking-color);
  border-radius: 0;
}

/* small animations */
@keyframes moveRoadMarkings {
  0% {
    transform: translateX(0);
  }

  100% {
    transform: translateX(-50%);
  }
}

.animate-road {
  animation: moveRoadMarkings 2s linear infinite;
}

@keyframes shake {
  0%,
  100% {
    transform: translateY(0);
  }

  25% {
    transform: translateY(-1px);
  }

  50% {
    transform: translateY(1px);
  }

  75% {
    transform: translateY(-1px);
  }
}

.animate-shake {
  animation: shake 0.2s ease-in-out infinite;
}

/* brake lights */
.brake-lights {
  opacity: 0;
  transition: opacity 0.25s ease;
}

.brake-lights.active {
  opacity: 1;
}

/* legend */
.legend-row {
  display: flex;
  gap: 12px;
  align-items: center;
  flex-wrap: wrap;
  margin-top: 6px;
}

.legend-item {
  display: flex;
  gap: 8px;
  align-items: center;
  color: var(--slate);
  font-size: 0.95rem;
}

.swatch {
  width: 12px;
  height: 12px;
  border-radius: 3px;
  display: inline-block;
}

.thinking-swatch {
  background: var(--thinking-color);
}

.braking-swatch {
  background: var(--braking-color);
}

.hazard-swatch {
  background: var(--coral);
}

/* distance scale */
.distance-scale {
  margin-top: 8px;
}

.scale-bar {
  height: 28px;
  display: flex;
  gap: 0;
  border-radius: 6px;
  overflow: hidden;
}

.scale-seg {
  flex: 1;
  background: var(--gray-200);
  border-right: 1px solid var(--gray-300);
}

.scale-labels {
  display: flex;
  justify-content: space-between;
  margin-top: 6px;
  color: var(--slate);
  font-size: 0.9rem;
}

/* simulation status */
.simulation-status {
  margin-top: 8px;
  text-align: center;
  font-weight: 600;
  color: var(--slate);
}

/* controls grid */
.controls-grid {
  display: grid;
  grid-template-columns: 1fr 360px;
  gap: 18px;
  margin-top: 12px;
}

@media (max-width: 900px) {
  .controls-grid {
    grid-template-columns: 1fr;
  }
}

.controls-column {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.results-column {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.label {
  font-weight: 600;
  color: var(--navy);
  margin-bottom: 4px;
}

.slider {
  width: 100%;
  appearance: none;
  height: 6px;
  background: var(--gray-200);
  border-radius: 8px;
  touch-action: none;
}

.range-legend {
  display: flex;
  justify-content: space-between;
  color: var(--slate);
  font-size: 0.9rem;
  margin-top: 6px;
}

.center-text {
  text-align: center;
  color: var(--teal);
  font-weight: 700;
  margin-top: 6px;
}

.reaction-row {
  display: flex;
  gap: 8px;
  align-items: center;
}

.select {
  padding: 8px 10px;
  border-radius: 8px;
  border: 1px solid var(--gray-300);
  background: var(--white);
}

.results-box {
  background: var(--gray-100);
  padding: 12px;
  border-radius: 10px;
}

.results-title {
  margin: 0 0 8px 0;
  font-size: 1rem;
}

.result-row {
  display: flex;
  justify-content: space-between;
  margin-bottom: 6px;
  color: var(--navy);
}

.border-top {
  border-top: 1px solid var(--gray-300);
  padding-top: 8px;
  margin-top: 6px;
}

/* facts */
.facts-box {
  background: #f0f8ff;
  padding: 12px;
  border-radius: 10px;
  margin-top: 8px;
  color: var(--navy);
}

.facts-box ul {
  margin-top: 6px;
  padding-left: 18px;
  color: var(--slate);
}

/* small helpers */
.center {
  text-align: center;
}

/* accessibility */
[hidden] {
  display: none !important;
}

@media (prefers-reduced-motion: reduce) {
  .animate-road,
  .animate-shake {
    animation: none;
  }
}

/* responsive tweaks */
@media (max-width: 520px) {
  .card-inner {
    padding: 14px;
  }

  .road {
    height: 120px;
  }

  .controls-grid {
    gap: 12px;
  }
}