/* ==================================================================
   Orbital mechanics, slowly — design system
   ================================================================== */

:root {
  --bg:        #fdfdfa;
  --ink:       #111;
  --ink-soft:  #2c2c2c;
  --accent:    #ff6b35;
  --accent-dk: #d4521e;
  --secondary: #2c5aa0;
  --secondary-dk: #1d3f76;
  --grid:      #e6e6e6;
  --grid-soft: #f1f1ed;
  --muted:     #666;
  --muted-2:   #999;
  --paper:     #ffffff;
  --space:     #0a0e17;

  --serif: "Source Serif Pro", "Iowan Old Style", Georgia, serif;
  --sans:  "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --mono:  "SF Mono", "Menlo", "Consolas", monospace;

  --col:       720px;
  --col-wide:  1100px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--serif);
  font-size: 18px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

article {
  margin: 0 auto;
  padding: 4rem 1rem 6rem;
}

article > * { max-width: var(--col); margin-left: auto; margin-right: auto; }
article .wide { max-width: var(--col-wide); }

h1, h2, h3, h4 {
  font-family: var(--sans);
  color: var(--ink);
  letter-spacing: -0.01em;
  line-height: 1.2;
}

h1 {
  font-size: clamp(2.4rem, 5vw, 3.6rem);
  font-weight: 600;
  margin: 0.2em 0;
}
h1 em { color: var(--accent); font-style: italic; font-family: var(--serif); font-weight: 500; }

h2 {
  font-size: 1.6rem;
  font-weight: 600;
  margin: 3rem 0 1rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--grid);
}

h3 {
  font-size: 1.15rem;
  font-weight: 600;
  margin: 2rem 0 0.5rem;
}

p { margin: 0 auto 1.1em; }
p em { color: var(--ink); font-style: italic; }
code {
  font-family: var(--mono);
  font-size: 0.9em;
  background: var(--grid-soft);
  padding: 0.05em 0.3em;
  border-radius: 3px;
}

/* Hero ----------------------------------------------------------- */
.hero { text-align: left; padding: 1rem 0 2rem; }
.kicker {
  font-family: var(--sans);
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--accent);
  font-weight: 500;
  margin-bottom: 1.5rem;
}
.lede {
  font-size: 1.2rem;
  line-height: 1.5;
  color: var(--ink-soft);
  margin: 1.5rem 0 2rem;
  max-width: 640px;
}
.byline {
  color: var(--muted);
  font-family: var(--sans);
  font-size: 0.85rem;
  margin-top: 2rem;
}
.hero-widget {
  margin: 2rem 0;
  height: 280px;
  width: 100%;
  position: relative;
  background: var(--space);
  border-radius: 6px;
  overflow: hidden;
}
.caption {
  font-family: var(--sans);
  font-size: 0.88rem;
  color: var(--muted);
  font-style: italic;
  margin-top: 0.5em;
}

/* Section rule --------------------------------------------------- */
.rule {
  border: 0;
  border-top: 1px solid var(--grid);
  margin: 4rem auto;
  width: 6rem;
}

/* Widgets -------------------------------------------------------- */
.widget {
  background: var(--paper);
  border: 1px solid var(--grid);
  border-radius: 6px;
  padding: 1.4rem 1.4rem 1.6rem;
  margin: 1.8rem auto 1.5rem;
  box-shadow: 0 1px 0 rgba(0,0,0,0.02);
}

.widget-header { margin-bottom: 1rem; }
.widget-header h3 {
  margin: 0 0 0.3em;
  font-size: 1rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--ink);
}
.widget-header p {
  font-family: var(--sans);
  font-size: 0.9rem;
  color: var(--muted);
  margin: 0;
}

.recap {
  background: var(--grid-soft);
  border-left: 3px solid var(--accent);
  padding: 0.9em 1.1em;
  font-family: var(--sans);
  font-size: 0.92rem;
  line-height: 1.55;
  color: var(--ink-soft);
  margin: 1.5rem auto 2rem;
}

/* Buttons -------------------------------------------------------- */
button {
  font-family: var(--sans);
  font-size: 0.88rem;
  font-weight: 500;
  background: var(--paper);
  color: var(--ink);
  border: 1px solid var(--grid);
  padding: 0.45em 0.9em;
  border-radius: 4px;
  cursor: pointer;
  transition: all 0.12s ease;
}
button:hover { border-color: var(--ink); }
button:active { background: var(--grid-soft); }
button.primary {
  background: var(--accent);
  color: white;
  border-color: var(--accent);
}
button.primary:hover { background: var(--accent-dk); border-color: var(--accent-dk); }
button.secondary {
  background: var(--secondary);
  color: white;
  border-color: var(--secondary);
}
button.secondary:hover { background: var(--secondary-dk); border-color: var(--secondary-dk); }

.ctrl-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5em;
  align-items: center;
  margin-top: 1rem;
}
.ctrl-row.tiny {
  font-family: var(--sans);
  font-size: 0.85rem;
  color: var(--muted);
  margin-top: 0.6rem;
}
.toggle {
  font-family: var(--sans);
  font-size: 0.88rem;
  color: var(--ink-soft);
  user-select: none;
}
.toggle input { vertical-align: middle; margin-right: 0.4em; }

/* Slider rows --------------------------------------------------- */
.slider-row {
  display: grid;
  grid-template-columns: 6em minmax(60px, 1fr) 4.5em;
  gap: 0.6em;
  align-items: center;
  font-family: var(--sans);
  font-size: 0.86rem;
  color: var(--ink-soft);
  margin: 0.45em 0;
}
.slider-row label { color: var(--muted); }
.slider-row input[type=range] { width: 100%; }
.slider-row .val {
  font-family: var(--mono);
  font-size: 0.92rem;
  color: var(--ink);
  text-align: right;
}

/* Readout panel ------------------------------------------------- */
.readout {
  font-family: var(--sans);
  font-size: 0.92rem;
  color: var(--ink-soft);
  background: var(--grid-soft);
  padding: 0.8em 1em;
  border-radius: 4px;
  margin: 0.8em 0;
  display: flex;
  flex-wrap: wrap;
  gap: 1.3em;
}
.readout .item { display: flex; align-items: baseline; gap: 0.4em; }
.readout .item .v {
  font-family: var(--mono);
  font-size: 1.05rem;
  color: var(--ink);
  font-weight: 600;
}
.readout .item .lbl { color: var(--muted); }
.readout.tag {
  display: inline-flex;
  font-size: 0.95rem;
  font-weight: 500;
  padding: 0.5em 0.9em;
}
.readout.tag .v { color: var(--accent); }

/* Widget two-column layouts ------------------------------------- */
.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  align-items: start;
}
.two-col-13 {
  display: grid;
  grid-template-columns: 1fr 1.5fr;
  gap: 1.5rem;
  align-items: start;
}
.two-col-31 {
  display: grid;
  grid-template-columns: 1.3fr 1fr;
  gap: 1.5rem;
  align-items: start;
  min-width: 0;
}
.two-col-31 > * { min-width: 0; }

/* SVG containers ----------------------------------------------- */
.canvas-wrap {
  width: 100%;
  background: var(--space);
  border-radius: 4px;
  position: relative;
  overflow: hidden;
}
.canvas-wrap.light {
  background: var(--paper);
  border: 1px solid var(--grid);
}
.canvas-wrap svg {
  display: block;
  width: 100%;
  height: auto;
}

/* Chart small ----------------------------------------------- */
.chart {
  width: 100%;
  background: var(--paper);
  border: 1px solid var(--grid);
  border-radius: 4px;
  padding: 0.5em;
}

/* Footer -------------------------------------------------- */
footer { margin-top: 5rem; }
footer p {
  font-family: var(--sans);
  font-size: 0.85rem;
  color: var(--muted);
}

/* KaTeX overrides ----------------------------------------- */
.katex-display { margin: 1.1em 0; }
.katex { font-size: 1em; }

/* Side-by-side mini panels ------------------------------- */
.dual {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}
.dual .panel-label {
  font-family: var(--sans);
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--muted);
  margin-bottom: 0.3em;
}

/* Lagrange tooltip card -------------------------------- */
.lagrange-card {
  font-family: var(--sans);
  background: var(--grid-soft);
  border-left: 3px solid var(--secondary);
  padding: 0.9em 1.1em;
  border-radius: 4px;
  margin-top: 0.9em;
  font-size: 0.92rem;
  min-height: 4em;
  color: var(--ink-soft);
}
.lagrange-card h4 {
  margin: 0 0 0.3em;
  font-size: 1rem;
  color: var(--ink);
}
.lagrange-card .missions {
  color: var(--accent);
  font-weight: 500;
  font-size: 0.88rem;
}

/* Responsive ---------------------------------------------------- */
@media (max-width: 760px) {
  body { font-size: 16px; }
  article { padding: 2rem 1rem 4rem; }
  .two-col, .two-col-13, .two-col-31, .dual {
    grid-template-columns: 1fr;
  }
  .slider-row {
    grid-template-columns: 7em 1fr 4em;
  }
}