:root {
  color-scheme: light dark;
  --bg: #f7fafb;
  --text: #16202a;
  --muted: #5d6875;
  --line: #d3dbe3;
  --panel: #ffffff;
  --accent: #0b6d86;
  --accent-2: #c2185b;
  --grid: #e6ebf0;
  --shadow: 0 1px 2px rgba(16, 24, 40, 0.08);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111820;
    --text: #f2f6fa;
    --muted: #b7c1cc;
    --line: #303a45;
    --panel: #18222d;
    --accent: #6bd3ef;
    --accent-2: #ff8ab5;
    --grid: #26313c;
    --shadow: none;
  }
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.5 system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

main {
  width: min(1040px, calc(100% - 28px));
  margin: 0 auto;
  padding: 24px 0 44px;
}

h1,
h2,
p {
  margin-top: 0;
}

h1 {
  margin-bottom: 8px;
  font-size: clamp(2rem, 7vw, 3.4rem);
  line-height: 1;
  letter-spacing: 0;
}

h2 {
  margin-bottom: 10px;
  font-size: 1.15rem;
}

p {
  color: var(--muted);
}

a {
  color: var(--accent);
}

.back-link {
  display: inline-block;
  margin-bottom: 14px;
}

.page-header {
  margin-bottom: 20px;
}

.panel {
  margin: 14px 0;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  box-shadow: var(--shadow);
}

.control-row {
  display: grid;
  grid-template-columns: 132px 1fr;
  gap: 12px;
  align-items: center;
  margin-bottom: 14px;
}

.button-group {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

button {
  border: 1px solid var(--line);
  border-radius: 6px;
  background: transparent;
  color: var(--text);
  padding: 8px 11px;
  font: inherit;
  cursor: pointer;
}

button.active {
  border-color: var(--accent);
  background: color-mix(in srgb, var(--accent) 16%, transparent);
}

.control-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

label span {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  color: var(--muted);
  font-size: 0.92rem;
}

input[type="range"] {
  width: 100%;
  margin-top: 8px;
}

.toggles {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  margin-top: 14px;
}

.display-controls {
  margin: 4px 4px 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 10px 12px 12px;
}

.display-controls summary {
  color: var(--muted);
  cursor: pointer;
  font-weight: 650;
}

.display-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin-top: 12px;
}

.plot-controls {
  display: grid;
  grid-template-columns: minmax(240px, 1fr) auto;
  gap: 14px;
  align-items: end;
  padding: 4px 4px 12px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 8px;
}

.plot-controls .toggles {
  margin-top: 0;
  justify-content: flex-end;
}

.chart-panel {
  padding: 12px;
}

.chart-header {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: baseline;
  padding: 4px 4px 0;
}

.chart-header h2 {
  margin-bottom: 0;
}

.chart-header p {
  margin-bottom: 0;
  text-align: right;
}

svg {
  display: block;
  width: 100%;
  min-height: 300px;
}

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

.axis {
  stroke: var(--muted);
}

.curve {
  fill: none;
  stroke: var(--accent);
  stroke-width: 3;
}

.drop-disc {
  fill: rgba(93, 190, 220, 0.05);
}

.drop-outline {
  fill: none;
  stroke: var(--accent);
  stroke-width: 2;
}

.ray-segment {
  fill: none;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.marker-line {
  stroke: var(--accent-2);
  stroke-width: 1.5;
  stroke-dasharray: 5 4;
}

.marker-dot,
.extremum-dot {
  fill: var(--accent-2);
  stroke: var(--panel);
  stroke-width: 2;
}

.extremum-dot {
  fill: var(--accent);
}

.axis-label,
.tick-label,
.point-label {
  fill: var(--muted);
  font-size: 12px;
}

.point-label {
  fill: var(--text);
}

.details {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 14px;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.93rem;
}

th,
td {
  padding: 7px 6px;
  border-bottom: 1px solid var(--line);
  text-align: right;
}

th:first-child,
td:first-child {
  text-align: left;
}

.small {
  margin-top: 12px;
  margin-bottom: 0;
  font-size: 0.9rem;
}

.warning {
  color: var(--accent-2);
}

@media (max-width: 760px) {
  .control-row,
  .control-grid,
  .display-grid,
  .plot-controls,
  .details {
    grid-template-columns: 1fr;
  }

  .plot-controls .toggles {
    justify-content: flex-start;
  }

  .chart-header {
    display: block;
  }

  .chart-header p {
    margin-top: 4px;
    text-align: left;
  }

  .panel {
    padding: 14px;
  }

  th,
  td {
    padding: 6px 4px;
  }
}