:root {
  color-scheme: light;
  --bg: #f4f6f8;
  --panel: #ffffff;
  --panel-strong: #eef3f6;
  --ink: #18232e;
  --muted: #64717f;
  --frame: #b8e3e8;
  --camera: #c7ddf2;
  --iris: #f6d7ad;
  --sensor: #cde9c8;
  --lens: #d7c8f0;
  --frame-ink: #5e9da6;
  --camera-ink: #6c93b7;
  --iris-ink: #b8894f;
  --sensor-ink: #78a978;
  --lens-ink: #9277bc;
  --axis: #2d3b49;
  --grid: #d9e1e7;
  --danger: #c8504c;
  --danger-soft: #f4c6bf;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--ink);
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    sans-serif;
}

a {
  color: inherit;
  text-decoration: none;
}

.tool-header,
.tool-footer {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  padding: 16px 18px 0;
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 750;
}

.brand-link {
  color: var(--ink);
}

.back-link:hover,
.back-link:focus-visible {
  color: var(--ink);
}

.tool-footer {
  flex-wrap: wrap;
  padding: 0 18px 18px;
}

.app-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 290px;
  gap: 18px;
  min-height: calc(100vh - 90px);
  padding: 18px;
}

.canvas-panel,
.controls {
  background: var(--panel);
  border: 1px solid #d7e0e7;
  box-shadow: 0 16px 48px rgb(23 35 46 / 0.08);
}

.canvas-panel {
  display: flex;
  flex-direction: column;
  min-width: 0;
  padding: 16px;
  border-radius: 8px;
}

.plot-header {
  padding: 6px 4px 12px;
}

.plot-header h1 {
  margin: 0;
  color: var(--ink);
  font-size: 1.55rem;
  line-height: 1.1;
}

.plot-header p {
  max-width: 760px;
  margin: 6px 0 0;
  color: var(--muted);
  font-size: 0.95rem;
  line-height: 1.4;
}

svg {
  display: block;
  width: 100%;
  min-height: 380px;
}

.below-chart {
  display: grid;
  grid-template-columns: minmax(260px, 360px) minmax(320px, 1fr);
  gap: 14px;
  margin-top: 14px;
}

.sensor-card,
.summary-card {
  min-width: 0;
  background: rgb(255 255 255 / 0.86);
  border: 1px solid #d7e0e7;
  border-radius: 8px;
}

.sensor-card {
  padding: 10px;
}

.summary-card {
  padding: 18px 20px;
}

#sensor-detail-drawing {
  min-height: 210px;
}

.summary-list {
  display: grid;
  gap: 14px;
  margin: 0;
}

.summary-list div {
  display: grid;
  grid-template-columns: minmax(0, 1fr) max-content;
  align-items: baseline;
  gap: 18px;
}

.summary-list dt,
.summary-list dd {
  margin: 0;
  font-variant-numeric: tabular-nums;
}

.summary-list dt {
  color: var(--muted);
  font-size: 0.95rem;
  font-weight: 800;
}

.summary-list dd {
  color: var(--ink);
  font-size: 1rem;
  font-weight: 850;
  text-align: right;
}

.controls {
  align-self: start;
  border-radius: 8px;
  padding: 18px;
}

.solve-panel {
  display: grid;
  gap: 10px;
  margin: 0 0 24px;
  padding: 0 0 20px;
  border: 0;
  border-bottom: 1px solid #d7e0e7;
}

legend,
label {
  color: var(--muted);
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0;
  text-transform: uppercase;
}

legend {
  margin-bottom: 10px;
}

.radio-row {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--muted);
}

.radio-row input {
  width: 18px;
  height: 18px;
  margin: 0;
  accent-color: var(--lens-ink);
}

.control-row {
  display: grid;
  gap: 4px;
  margin: 0 0 14px;
}

input[type="range"] + .control-row,
input[type="range"] + .select-control {
  margin-top: 24px;
}

input[type="range"] + .secondary-readout {
  margin-top: 12px;
}

.secondary-readout {
  margin-bottom: 24px;
}

.select-control {
  display: grid;
  gap: 8px;
}

select {
  width: 100%;
  min-height: 42px;
  padding: 0 12px;
  color: var(--ink);
  background: var(--panel);
  border: 1px solid #c9d4dc;
  border-radius: 8px;
  font: inherit;
  font-size: 0.95rem;
  font-weight: 700;
}

select:focus-visible,
input[type="range"]:focus,
input[type="range"]:focus-visible,
.radio-row input:focus-visible {
  outline: none;
  box-shadow:
    0 0 0 3px #ffffff,
    0 0 0 6px rgb(146 119 188 / 0.35);
}

output {
  color: var(--ink);
  font-variant-numeric: tabular-nums;
  font-size: 1.5rem;
  font-weight: 750;
  line-height: 1.1;
}

#pixels-output,
label[for="pixels-slider"],
#eye-in-view-output,
label[for="eye-in-view-output"] {
  color: var(--iris-ink);
}

.is-under-target,
output.is-under-target,
label.is-under-target {
  color: var(--danger) !important;
}

svg .is-under-target {
  fill: var(--danger) !important;
  stroke: var(--panel);
}

#iris-ring.is-under-target,
#sensor-iris.is-under-target {
  fill: var(--danger-soft);
  stroke: var(--danger);
}

#sensor-eye.is-under-target {
  stroke: var(--danger);
}

#distance-output,
label[for="distance-slider"] {
  color: var(--frame-ink);
}

#fov-output,
label[for="fov-slider"],
#focal-output,
label[for="focal-slider"] {
  color: var(--lens-ink);
}

#resolution-output,
label[for="resolution-slider"] {
  color: var(--camera-ink);
}

#sensor-output,
label[for="sensor-select"] {
  color: var(--sensor-ink);
}

input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  height: 12px;
  width: 100%;
  border: 1px solid #c9d4dc;
  border-radius: 999px;
  outline: none;
}

input[type="range"]:disabled {
  cursor: not-allowed;
  opacity: 0.64;
}

select:disabled {
  cursor: not-allowed;
  opacity: 0.64;
}

#pixels-slider {
  background: var(--iris);
}

#distance-slider {
  background: var(--frame);
}

#fov-slider,
#focal-slider {
  background: var(--lens);
}

#resolution-slider {
  background: var(--camera);
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 22px;
  height: 22px;
  border: 2px solid #ffffff;
  border-radius: 50%;
  box-shadow: 0 1px 4px rgb(24 35 46 / 0.24);
}

#pixels-slider::-webkit-slider-thumb {
  background: var(--iris-ink);
}

#distance-slider::-webkit-slider-thumb {
  background: var(--frame-ink);
}

#fov-slider::-webkit-slider-thumb,
#focal-slider::-webkit-slider-thumb {
  background: var(--lens-ink);
}

#resolution-slider::-webkit-slider-thumb {
  background: var(--camera-ink);
}

input[type="range"]::-moz-range-track {
  height: 12px;
  border: 1px solid #c9d4dc;
  border-radius: 999px;
}

input[type="range"]::-moz-range-thumb {
  width: 18px;
  height: 18px;
  border: 2px solid #ffffff;
  border-radius: 50%;
  box-shadow: 0 1px 4px rgb(24 35 46 / 0.24);
}

#pixels-slider::-moz-range-track {
  background: var(--iris);
}

#distance-slider::-moz-range-track {
  background: var(--frame);
}

#fov-slider::-moz-range-track,
#focal-slider::-moz-range-track {
  background: var(--lens);
}

#resolution-slider::-moz-range-track {
  background: var(--camera);
}

#pixels-slider::-moz-range-thumb {
  background: var(--iris-ink);
}

#distance-slider::-moz-range-thumb {
  background: var(--frame-ink);
}

#fov-slider::-moz-range-thumb,
#focal-slider::-moz-range-thumb {
  background: var(--lens-ink);
}

#resolution-slider::-moz-range-thumb {
  background: var(--camera-ink);
}

.computed-values {
  display: grid;
  margin-top: 24px;
}

.computed-row {
  margin-bottom: 18px;
}

.computed-label {
  color: var(--lens-ink);
}

.grid line {
  stroke: var(--grid);
  stroke-width: 1;
}

.grid text {
  fill: var(--muted);
  font-size: 14px;
  font-variant-numeric: tabular-nums;
  font-weight: 650;
  user-select: none;
}

#fov-wedge {
  fill: rgb(184 227 232 / 0.24);
  stroke: none;
}

#fov-top-ray,
#fov-bottom-ray,
#frame-width-line {
  stroke: var(--frame-ink);
  stroke-linecap: round;
}

#fov-top-ray,
#fov-bottom-ray {
  stroke-dasharray: 8 8;
  stroke-width: 2.5;
}

#frame-width-line {
  stroke-width: 3;
}

#optical-axis {
  stroke: var(--axis);
  stroke-dasharray: 7 7;
  stroke-linecap: round;
  stroke-width: 2;
}

#arrow-positive path {
  fill: var(--axis);
}

#sensor-plane,
#camera-body,
#camera-top {
  fill: #eef7ff;
  stroke: var(--camera);
  stroke-width: 2;
}

#camera-lens {
  fill: var(--lens);
  stroke: var(--lens-ink);
  stroke-linejoin: round;
  stroke-width: 2;
}

#iris-eye,
#sensor-eye {
  fill: #fff4df;
  stroke: var(--iris-ink);
  stroke-width: 2;
}

#sensor-eye {
  clip-path: url("#sensor-frame-clip");
  opacity: 0.78;
}

#iris-ring {
  fill: rgb(184 227 232 / 0.7);
  stroke: var(--frame-ink);
  stroke-width: 2;
}

#iris-pupil {
  fill: var(--axis);
}

#iris-diameter-line {
  stroke: var(--iris-ink);
  stroke-linecap: round;
  stroke-width: 3;
}

#sensor-frame {
  fill: var(--panel-strong);
  stroke: var(--sensor-ink);
  stroke-width: 2;
}

#sensor-iris {
  fill: var(--iris);
  stroke: var(--iris-ink);
  stroke-width: 2;
}

#frame-width-label,
#camera-label,
#iris-label,
#iris-pixel-label,
#sensor-label,
#sensor-iris-label {
  font-size: 15px;
  font-weight: 800;
  paint-order: stroke;
  stroke: var(--panel);
  stroke-linejoin: round;
  stroke-width: 5px;
  user-select: none;
}

#frame-width-label {
  fill: var(--frame-ink);
}

#camera-label {
  fill: var(--camera-ink);
}

#iris-label,
#iris-pixel-label,
#sensor-iris-label {
  fill: var(--iris-ink);
}

#sensor-label {
  fill: var(--sensor-ink);
}

#summary-pixels-value {
  color: var(--iris-ink);
}

#summary-distance-value,
#summary-resolution-value {
  color: var(--frame-ink);
}

#summary-fov-value,
#summary-focal-value {
  color: var(--lens-ink);
}

#summary-sensor-value {
  color: var(--sensor-ink);
}

#scale-note {
  fill: var(--muted);
  font-size: 13px;
  font-weight: 600;
  opacity: 0.78;
  user-select: none;
}

@media (max-width: 820px) {
  .app-shell {
    grid-template-columns: 1fr;
    padding: 12px;
  }

  .controls {
    order: 1;
  }

  .control-row {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: baseline;
    column-gap: 14px;
  }

  .computed-values {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px;
  }

  .computed-row {
    display: block;
    margin-bottom: 0;
  }

  .below-chart {
    grid-template-columns: 1fr;
  }

  output {
    font-size: 1.32rem;
    text-align: right;
    white-space: nowrap;
  }
}