/* ==================================================================
   Quantum computing, 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;

  --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;
}

/* All inline blocks default to a centered narrow column. */
article > * { max-width: var(--col); margin-left: auto; margin-right: auto; }

/* Wide widgets break out. */
article .wide { max-width: var(--col-wide); }

/* Headings ------------------------------------------------------- */

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;
}

/* Paragraphs ----------------------------------------------------- */
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: 200px;
  width: 100%;
  position: relative;
}
.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.link-btn {
  background: transparent;
  border: none;
  padding: 0.2em 0.4em;
  color: var(--secondary);
  text-decoration: underline;
}
button.link-btn:hover { color: var(--accent); border-color: transparent; }

.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; }

/* ============== Bloch sphere section ============== */
.bloch-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.8rem;
  align-items: center;
}
#bloch-canvas {
  width: 100%;
  aspect-ratio: 1 / 1;
  background: radial-gradient(circle at 30% 30%, #fff 0%, #f5f5f0 100%);
  border-radius: 6px;
  position: relative;
  touch-action: none;
}
.bloch-readout {
  font-family: var(--sans);
}
.readout-row {
  display: flex;
  align-items: baseline;
  gap: 0.6em;
  font-size: 1rem;
  margin: 0.4em 0;
}
.readout-row .lbl { color: var(--muted); min-width: 1.5em; }
.readout-row .val {
  font-family: var(--mono);
  font-size: 1.05rem;
  color: var(--ink);
  font-weight: 500;
}
.readout-row .unit { color: var(--muted-2); font-size: 0.85em; }
.readout-state {
  background: var(--grid-soft);
  padding: 0.7em 1em;
  border-radius: 4px;
  margin: 1em 0;
  font-size: 1.05rem;
  text-align: center;
}
.prob-bars { margin: 1em 0; }
.pb-row {
  display: grid;
  grid-template-columns: 3.2em 1fr 3.5em;
  gap: 0.6em;
  align-items: center;
  margin: 0.35em 0;
  font-size: 0.95rem;
}
.pb-bar {
  height: 14px;
  background: var(--grid-soft);
  border-radius: 2px;
  overflow: hidden;
}
.pb-fill {
  height: 100%;
  transition: width 0.15s ease-out;
}
.pb-fill.p0 { background: var(--secondary); }
.pb-fill.p1 { background: var(--accent); }
.pb-num { font-family: var(--mono); font-size: 0.85em; text-align: right; }
.preset-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4em;
  margin-top: 1em;
}
.preset-row button { padding: 0.3em 0.65em; font-size: 0.82rem; }

/* ============== Interference ============== */
#interference-stage {
  width: 100%;
  background: var(--paper);
  border-radius: 4px;
}
#iv-narration {
  font-style: italic;
  color: var(--ink-soft);
  background: var(--grid-soft);
  padding: 0.7em 1em;
  border-radius: 4px;
  min-height: 1.4em;
}

/* ============== Measurement ============== */
.meas-controls {
  margin: 1rem 0;
  font-family: var(--sans);
  font-size: 0.92rem;
}
.meas-controls label { display: block; margin-bottom: 0.4em; color: var(--ink-soft); }
.meas-controls input[type="range"] { width: 100%; }
.meas-basis-row { display: flex; gap: 0.5em; margin-top: 1em; flex-wrap: wrap; }
#meas-histogram { width: 100%; min-height: 200px; }
.meas-readout {
  font-family: var(--sans);
  font-size: 0.9rem;
  color: var(--ink-soft);
  background: var(--grid-soft);
  padding: 0.7em 1em;
  border-radius: 4px;
  margin-top: 1em;
  min-height: 1.2em;
}

/* ============== Bell ============== */
.bell-grid {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 1.5rem;
  align-items: center;
}
#bell-circuit { width: 100%; }
#bell-amplitudes { width: 100%; min-height: 200px; }
#bell-histogram { width: 100%; min-height: 150px; margin-top: 1rem; }

/* ============== Circuit ============== */
.circuit-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 1.5rem;
}
#circuit-canvas { width: 100%; min-height: 200px; }
#circuit-state { width: 100%; }
#gate-palette { gap: 0.35em; }
#gate-palette button {
  font-size: 0.8rem;
  padding: 0.35em 0.7em;
}

/* ============== Grover ============== */
#grover-stage { width: 100%; min-height: 280px; }
.grover-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;
}
.grover-readout .item { display: flex; align-items: baseline; gap: 0.4em; }
.grover-readout .item .v {
  font-family: var(--mono);
  font-size: 1.05rem;
  color: var(--ink);
  font-weight: 600;
}
.grover-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 1em;
  font-family: var(--sans);
  font-size: 0.88rem;
}
.grover-table th, .grover-table td {
  text-align: left;
  padding: 0.4em 0.7em;
  border-bottom: 1px solid var(--grid);
}
.grover-table th {
  color: var(--muted);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  font-size: 0.78rem;
}
.grover-table tr.optimal td { background: rgba(255,107,53,0.08); }
.grover-table td.numeric { font-family: var(--mono); }

/* ============== QFT ============== */
.qft-controls {
  font-family: var(--sans);
  font-size: 0.92rem;
  color: var(--ink-soft);
  margin: 1rem 0;
}
.qft-controls input[type="range"] { width: 100%; margin-top: 0.5em; }
.qft-controls .hint { display: block; margin-top: 0.6em; color: var(--muted); font-size: 0.85em; font-style: italic; }
#qft-input, #qft-output {
  width: 100%;
  min-height: 130px;
  margin-top: 1em;
}

/* ============== Shor ============== */
.shor-controls {
  display: flex;
  gap: 1.2em;
  align-items: center;
  margin: 1rem 0;
  font-family: var(--sans);
  font-size: 0.92rem;
}
.shor-controls select {
  font-family: var(--mono);
  font-size: 1rem;
  padding: 0.3em 0.5em;
  border: 1px solid var(--grid);
  border-radius: 3px;
  background: var(--paper);
}
.shor-steps {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4em;
  margin: 1em 0;
}
.shor-steps button {
  font-size: 0.82rem;
  padding: 0.4em 0.7em;
}
.shor-steps button.done {
  background: var(--secondary);
  color: white;
  border-color: var(--secondary);
}
#shor-plot { width: 100%; min-height: 240px; }
.shor-log {
  font-family: var(--mono);
  font-size: 0.82rem;
  background: #1a1a1a;
  color: #e6e6e6;
  padding: 0.9em 1em;
  border-radius: 4px;
  margin-top: 1em;
  min-height: 4em;
  white-space: pre-wrap;
  line-height: 1.4;
  overflow-x: auto;
}
.shor-log .accent { color: #ff6b35; }
.shor-log .sec { color: #67a0ff; }
.shor-log .muted { color: #888; }

#shor-flow-canvas { width: 100%; min-height: 160px; }

/* ============== Timeline ============== */
#timeline-svg { width: 100%; min-height: 160px; }
.timeline-card {
  font-family: var(--sans);
  background: var(--grid-soft);
  padding: 1.1em 1.3em;
  border-radius: 4px;
  margin-top: 1em;
  border-left: 3px solid var(--secondary);
  font-size: 0.95rem;
  min-height: 5em;
}
.timeline-card h4 {
  font-size: 1rem;
  margin: 0 0 0.4em;
  color: var(--ink);
}
.timeline-card .year {
  font-family: var(--mono);
  color: var(--accent);
  font-weight: 600;
}

/* ============== Generic small styles ============== */
footer { margin-top: 5rem; }

.katex-display { margin: 1.1em 0; }
.katex { font-size: 1em; }

/* Responsive ---------------------------------------------------- */
@media (max-width: 760px) {
  body { font-size: 16px; }
  article { padding: 2rem 1rem 4rem; }
  .bloch-layout, .bell-grid, .circuit-grid {
    grid-template-columns: 1fr;
  }
  #bloch-canvas { max-width: 360px; margin: 0 auto; }
}