/* ============================================================
   Buck simulator — standalone vanilla CSS.
   Combines kristianskorpen.com site chrome (header, footer, nav,
   buttons, eyebrow) with the buck-sim-specific layout (schematic
   frame, param list, code panel, scope panel, sim-strip).
   Inherits tokens from colors_and_type.css.
   ============================================================ */

* { box-sizing: border-box; }

html, body { margin: 0; padding: 0; }
body {
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-hover); text-decoration: underline; }

/* ─────────── site header (matches kristianskorpen.com) ─────────── */
header.site {
  border-bottom: 1px solid var(--border);
  background: rgba(250,250,246,0.92);
  position: sticky; top: 0; z-index: 50;
  backdrop-filter: blur(6px);
}
header.site .inner {
  max-width: var(--wide-max);
  margin: 0 auto;
  padding: 14px 22px;
  display: flex; align-items: center; gap: 22px;
}
.brand {
  display: inline-flex; align-items: center; gap: 12px;
  text-decoration: none; color: var(--ink-900);
}
.brand img { height: 30px; width: auto; display: block; }
.brand .name { font-family: var(--font-serif); font-weight: 600; font-size: 17px; line-height: 1; }
header.site nav { display: flex; gap: 22px; margin-left: auto; }
header.site nav a {
  color: var(--ink-900); text-decoration: none; font-size: 14.5px;
  border-bottom: 1px solid transparent; padding-bottom: 2px;
  transition: border-color var(--dur-fast);
}
header.site nav a:hover { border-bottom-color: var(--ink-300); }
header.site nav a.current { border-bottom-color: var(--accent); color: var(--accent); }

/* ─────────── main wrapper ─────────── */
main { max-width: var(--wide-max); margin: 0 auto; padding: 32px 22px 60px; }

/* breadcrumb */
.breadcrumb { font-size: 13px; color: var(--fg-soft); margin: 4px 0 18px; }
.breadcrumb a { color: var(--fg-soft); }
.breadcrumb a:hover { color: var(--accent); }
.breadcrumb .sep { margin: 0 6px; color: var(--ink-300); }

/* hero */
.tool-hero { padding: 12px 0 28px; border-bottom: 1px solid var(--border); margin-bottom: 24px; }
.tool-hero .eyebrow {
  display: inline-block; font-family: var(--font-mono);
  font-size: 11px; letter-spacing: 0.12em; text-transform: uppercase;
  color: var(--accent); font-weight: 600; margin-bottom: 10px;
}
.tool-hero h1 {
  font-family: var(--font-serif); font-weight: 600;
  font-size: 38px; line-height: 1.1; letter-spacing: -0.02em;
  margin: 0 0 12px; max-width: 18em;
}
.tool-hero .lead {
  font-size: 17px; line-height: 1.55; color: var(--fg-soft);
  max-width: 40em; margin: 0;
}
.tool-hero .lead code {
  font-family: var(--font-mono); font-size: 0.88em;
  background: var(--ink-100); padding: 1px 5px; border-radius: 3px;
}

/* ─────────── step header (mirrors Plot Explorer) ─────────── */
.step { padding: 22px 0; }
.step + .step { border-top: 1px solid var(--border); }
.step-head { display: flex; align-items: center; gap: 12px; margin-bottom: 16px; flex-wrap: wrap; }
.step-num {
  display: inline-flex; align-items: center; justify-content: center;
  width: 26px; height: 26px; border-radius: 50%;
  background: var(--accent); color: white; font-weight: 600; font-size: 13px;
  font-family: var(--font-mono); flex: 0 0 auto;
}
.step-head h2 {
  margin: 0; font-size: 19px; color: var(--ink-900);
  font-family: var(--font-serif); font-weight: 600;
}
.step-controls { margin-left: auto; display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.step-eyebrow {
  font-family: var(--font-mono);
  font-size: 11px; letter-spacing: 0.1em; text-transform: uppercase;
  color: var(--fg-soft); font-weight: 600;
}
.mode-toggle {
  display: inline-flex; gap: 0;
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-2);
  overflow: hidden;
  background: var(--bg-paper);
}
.mode-opt {
  font-family: var(--font-mono); font-size: 12px;
  padding: 6px 14px; cursor: pointer;
  background: transparent; border: 0;
  color: var(--fg-soft);
  letter-spacing: 0.02em;
  transition: background 120ms, color 120ms;
}
.mode-opt + .mode-opt { border-left: 1px solid var(--border-strong); }
.mode-opt:hover { background: var(--ink-100); color: var(--ink-900); }
.mode-opt.active { background: var(--accent); color: #fff; }

/* ─────────── buttons ─────────── */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  font-family: var(--font-sans);
  background: var(--accent); color: white; border: 1px solid var(--accent);
  border-radius: var(--radius-2);
  padding: 8px 18px; font-size: 14px; cursor: pointer;
  transition: background 120ms, border-color 120ms, transform 80ms;
  font-weight: 500;
}
.btn:hover { background: var(--accent-hover); border-color: var(--accent-hover); color: white; }
.btn:active { transform: translateY(1px); }
.btn:focus-visible { outline: none; box-shadow: var(--shadow-focus); }
.btn.big {
  padding: 10px 22px; font-size: 15px;
  font-family: var(--font-mono); font-weight: 600; letter-spacing: 0.02em;
}
.btn.ghost { background: transparent; color: var(--fg-soft); border-color: var(--border-strong); }
.btn.ghost:hover { background: var(--ink-100); color: var(--ink-900); }
.btn[disabled] { opacity: 0.45; cursor: not-allowed; }

/* ─────────── two-column layout ─────────── */
.bs-cols {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 22px;
  align-items: start;
}
@media (max-width: 900px) { .bs-cols { grid-template-columns: 1fr; } }
/* left column: schematic with the measurements panel stacked beneath it */
.bs-left { display: flex; flex-direction: column; gap: 16px; min-width: 0; }
.bs-left .meas-panel { margin: 0; }

/* ─────────── schematic ─────────── */
.schematic-frame {
  position: relative;
  background: var(--paper);
  border: 1px solid var(--border);
  border-radius: var(--radius-3);
  padding: 20px 28px;
  box-shadow: var(--shadow-1);
  background-image:
    linear-gradient(to right, rgba(31,138,76,0.04) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(31,138,76,0.04) 1px, transparent 1px);
  background-size: 16px 16px;
}
.schematic-frame .schematic-meta {
  display: flex; justify-content: space-between; align-items: baseline;
  font-family: var(--font-mono); font-size: 11px; color: var(--fg-muted);
  margin-bottom: 4px; letter-spacing: 0.04em;
}
.schematic-frame .schematic-meta b { color: var(--accent); font-weight: 600; }
.buck-svg { display: block; width: 100%; height: auto; max-height: 460px; }
.buck-svg .component { cursor: pointer; }
.buck-svg .component .hit { fill: transparent; pointer-events: all; }
.buck-svg .component .outline {
  fill: none;
  stroke: var(--accent);
  stroke-width: 1.5;
  opacity: 0;
  transition: opacity 120ms cubic-bezier(0.2, 0, 0.2, 1);
  pointer-events: none;
  rx: 4;
}
.buck-svg .component:hover .outline { opacity: 0.55; }
.buck-svg .component.selected .outline { opacity: 1; }
.buck-svg .math {
  font-family: "STIX Two Math", "Cambria Math", "Latin Modern Math", "Times New Roman", Times, serif;
  font-style: italic;
  fill: var(--ink-900);
}
.buck-svg .value-readout {
  font-family: var(--font-mono);
  font-size: 11px;
  fill: var(--green-700);
  font-variant-numeric: tabular-nums;
  font-weight: 500;
}
.buck-svg .polarity {
  font-family: serif;
  font-size: 17px;
  fill: var(--ink-900);
}

/* ─────────── card (sidebar) ─────────── */
.bs-card {
  background: var(--paper);
  border: 1px solid var(--border);
  border-radius: var(--radius-3);
  padding: 16px;
  box-shadow: var(--shadow-1);
}
.bs-card .section-label {
  font-family: var(--font-mono); font-size: 11px;
  letter-spacing: 0.1em; text-transform: uppercase;
  color: var(--fg-soft); font-weight: 600;
  margin-bottom: 10px;
}
.bs-card .section-divider { height: 1px; background: var(--border); margin: 14px 0; }

/* parameter list */
.param-list { display: flex; flex-direction: column; gap: 6px; }
.param-row {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 7px 12px;
  background: var(--bg-paper);
  border: 1px solid var(--border);
  border-radius: var(--radius-2);
  transition: border-color 120ms, background 120ms;
  cursor: pointer;
}
.param-row .pname { flex: 1 1 auto; }
.param-row .pval { flex: 0 0 auto; }
.param-row .punit { flex: 0 0 auto; }
.param-row .pdyn { flex: 0 0 auto; }
.param-row:hover { border-color: var(--border-strong); }
.param-row.selected {
  background: var(--accent-soft);
  border-color: var(--accent);
}
.param-row .pname {
  font-family: "STIX Two Math", "Cambria Math", Times, serif;
  font-style: italic;
  font-size: 15px;
  color: var(--ink-900);
}
.param-row .pname .sub {
  font-size: 0.7em;
  font-style: italic;
  vertical-align: sub;
}
.param-row .pval {
  font-family: var(--font-mono);
  color: var(--green-700);
  font-variant-numeric: tabular-nums;
  font-size: 13px;
  font-weight: 600;
  padding: 1px 6px;
  border-radius: 3px;
  background: var(--paper);
  border: 1px solid var(--border);
  outline: none;
  width: 6em;
  text-align: right;
}
.param-row .pval:focus {
  background: var(--accent-soft);
  border-color: var(--accent);
}
.param-row .pval.err {
  border-color: var(--danger-500);
  color: var(--danger-500);
  background: var(--danger-100);
}
.param-row .pval.clamped {
  border-color: var(--warn-500);
  color: var(--warn-500);
  background: var(--warn-100);
}
.param-row .pclamp {
  font-family: var(--font-mono); font-size: 10px;
  color: var(--warn-500); font-weight: 600;
  background: var(--warn-100);
  border: 1px solid var(--warn-500);
  border-radius: 4px; padding: 1px 5px;
  letter-spacing: 0.02em;
  white-space: nowrap;
}
.param-row.dynamic .pval {
  color: var(--green-700);
}
.param-row .pdyn {
  font-family: var(--font-mono); font-size: 10px;
  color: var(--accent); font-weight: 600;
  background: var(--accent-soft);
  border: 1px solid var(--accent);
  border-radius: 4px; padding: 1px 5px;
  letter-spacing: 0.02em;
  white-space: nowrap;
}
.param-note {
  font-family: var(--font-sans); font-size: 11.5px; line-height: 1.5;
  color: var(--fg-soft); margin: 10px 2px 0;
}
.param-note code {
  font-family: var(--font-mono); font-size: 10.5px;
  background: var(--bg-inset); padding: 0 4px; border-radius: 3px; color: var(--ink-700);
}
.param-note strong { color: var(--green-700); font-weight: 600; }
.param-note .pdyn-inline {
  font-family: var(--font-mono); font-size: 10px; color: var(--accent);
  background: var(--accent-soft); border: 1px solid var(--accent);
  border-radius: 4px; padding: 0 4px;
}
.param-row .punit {
  font-family: var(--font-mono); font-size: 11px;
  color: var(--fg-muted);
}

/* sim-settings field row */
.field-row { display: flex; flex-direction: column; gap: 10px; }
.field {
  display: flex; align-items: center; justify-content: space-between;
  font-family: var(--font-mono); font-size: 12px;
  color: var(--fg-soft); letter-spacing: 0.04em; text-transform: uppercase;
}
.field input[type="number"] {
  font-family: var(--font-mono); font-size: 13px;
  color: var(--green-700); font-weight: 600;
  background: var(--paper); border: 1px solid var(--border-strong);
  border-radius: 4px; padding: 3px 6px; width: 6em;
  text-align: right; outline: none;
}
.field input[type="number"]:focus { border-color: var(--accent); box-shadow: var(--shadow-focus); }
.field .unit { font-family: var(--font-mono); font-size: 12px; color: var(--fg-muted); margin-left: 6px; text-transform: none; }
.field .sym {
  font-family: var(--font-mono); font-size: 10px;
  color: var(--green-700); background: var(--accent-soft);
  border: 1px solid var(--accent); border-radius: 4px;
  padding: 0 4px; margin-left: 5px; text-transform: none; letter-spacing: 0;
}
.dt-readout {
  font-family: var(--font-mono); font-size: 11px;
  color: var(--green-700); font-weight: 600;
  letter-spacing: 0.04em;
  align-self: flex-start;
}
.dt-readout.clamped { color: var(--warn-500); }
.toggle-row {
  display: flex; align-items: center; gap: 8px;
  font-family: var(--font-mono); font-size: 12px;
  color: var(--ink-700);
  cursor: pointer; user-select: none;
}
.toggle-row input { accent-color: var(--accent); }

/* ─────────── block diagram (fig. 2) ─────────── */
.diagram-frame {
  position: relative;
  background: var(--paper);
  border: 1px solid var(--border);
  border-radius: var(--radius-3);
  padding: 18px 26px 8px;
  box-shadow: var(--shadow-1);
}
.diagram-frame .schematic-meta {
  display: flex; justify-content: space-between; align-items: baseline;
  font-family: var(--font-mono); font-size: 11px; color: var(--fg-muted);
  margin-bottom: 4px; letter-spacing: 0.04em;
}
.block-svg {
  display: block; width: 100%; height: auto;
  max-height: 220px;
}
.block-svg .math {
  font-family: "STIX Two Math", "Cambria Math", "Latin Modern Math", "Times New Roman", Times, serif;
  font-style: italic;
  fill: var(--ink-900);
}
.block-svg .polarity {
  font-family: serif;
  fill: var(--ink-900);
}

/* ─────────── code panel ─────────── */
.code-panel {
  background: var(--paper);
  border: 1px solid var(--border);
  border-radius: var(--radius-3);
  overflow: hidden;
  box-shadow: var(--shadow-1);
}
.code-head {
  display: flex; align-items: center; gap: 12px;
  padding: 8px 14px;
  background: var(--bg-paper);
  border-bottom: 1px solid var(--border);
}
.code-head .ftab {
  font-family: var(--font-mono); font-size: 12px;
  color: var(--ink-700); font-weight: 500;
}
.code-head .ftab .lang { color: var(--fg-muted); font-size: 11px; margin-left: 6px; }
.code-head .hint { margin-left: auto; font-family: var(--font-mono); font-size: 11px; color: var(--fg-muted); letter-spacing: 0.04em; }

/* tabbed variant — used for pi.c / pwm.c split */
.code-tabs {
  display: flex; align-items: stretch; gap: 0;
  background: var(--bg-paper);
  border-bottom: 1px solid var(--border);
}
.code-tab {
  appearance: none;
  background: transparent;
  border: 0;
  border-right: 1px solid var(--border);
  border-bottom: 2px solid transparent;
  padding: 10px 16px;
  cursor: pointer;
  display: flex; flex-direction: column; align-items: flex-start; gap: 2px;
  font-family: inherit;
  transition: background 120ms, border-color 120ms;
  text-align: left;
}
.code-tab:hover { background: var(--ink-100); }
.code-tab.active {
  background: var(--paper);
  border-bottom-color: var(--accent);
}
.code-tab .ftab {
  font-family: var(--font-mono); font-size: 12px;
  color: var(--ink-700); font-weight: 500;
}
.code-tab .ftab .lang { color: var(--fg-muted); font-size: 11px; margin-left: 6px; }
.code-tab .sig {
  font-family: var(--font-mono); font-size: 11px;
  color: var(--fg-soft); letter-spacing: 0.02em;
  display: inline-flex; align-items: baseline; gap: 3px;
}
.code-tab .sig .math {
  font-family: "STIX Two Math", "Cambria Math", Times, serif;
  font-style: italic; font-size: 12.5px;
  color: var(--ink-900);
}
.code-tab .sig sub.m {
  font-size: 9px;
  color: var(--fg-soft);
}
.code-tab .sig .arrow {
  margin: 0 4px;
  color: var(--fg-muted);
}
.code-tabs .hint {
  align-self: center;
  padding-right: 14px;
  font-family: var(--font-mono); font-size: 11px;
  color: var(--fg-muted); letter-spacing: 0.04em;
}

/* Narrow viewports: the five-tab strip (+ signatures + trailing hint) is
   wider than the panel and .code-panel's overflow:hidden was clipping the
   overflow invisibly — pwm.c / signals.py were unreachable. Make the strip
   its own horizontally-scrollable (swipeable) region instead, and drop the
   lower-priority chrome (per-tab signature, trailing hint) so more of the
   five tab names are visible without scrolling. */
@media (max-width: 700px) {
  .code-tabs {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scroll-snap-type: x proximity;
  }
  .code-tab { flex: 0 0 auto; scroll-snap-align: start; }
  .code-tab .sig { display: none; }
  .code-tabs .hint { display: none; }
}

/* execution-rate strip (per-block sample frequency) */
.rate-strip {
  display: flex; align-items: center; gap: 16px;
  padding: 8px 14px;
  background: var(--paper);
  border-bottom: 1px solid var(--border);
  font-family: var(--font-mono); font-size: 12px;
}
.rate-strip .rate-label {
  font-size: 10px; letter-spacing: 0.1em; text-transform: uppercase;
  color: var(--fg-soft); font-weight: 600;
}
.rate-strip .rate-field {
  display: inline-flex; align-items: center; gap: 7px;
  color: var(--ink-700);
}
.rate-strip .rate-field .m {
  font-family: "STIX Two Math", "Cambria Math", Times, serif;
  font-style: italic; color: var(--ink-900);
}
.rate-strip .rate-field .m sub { font-size: 0.7em; }
.rate-strip .rate-field .eq { color: var(--fg-muted); margin: 0 1px; }
.rate-strip .rate-field input.ts-expr {
  font-family: var(--font-mono); font-size: 13px;
  color: var(--green-700); font-weight: 600;
  background: var(--bg-paper); border: 1px solid var(--border-strong);
  border-radius: 4px; padding: 3px 9px; width: 13em;
  text-align: left; outline: none;
}
.rate-strip .rate-field input.ts-expr:focus { border-color: var(--accent); box-shadow: var(--shadow-focus); }
.rate-strip .rate-field input.ts-expr::placeholder { color: var(--fg-muted); font-weight: 400; }
.rate-strip .rate-derived.err { color: var(--danger-500); }
.rate-strip .rate-field input {
  font-family: var(--font-mono); font-size: 13px;
  color: var(--green-700); font-weight: 600;
  background: var(--bg-paper); border: 1px solid var(--border-strong);
  border-radius: 4px; padding: 3px 6px; width: 5em;
  text-align: right; outline: none;
}
.rate-strip .rate-field input:focus { border-color: var(--accent); box-shadow: var(--shadow-focus); }
.rate-strip .rate-field .unit { color: var(--fg-muted); }
.rate-strip .rate-derived {
  color: var(--fg-soft);
  display: inline-flex; align-items: center; gap: 6px;
}
.rate-strip .rate-derived b { color: var(--green-700); font-weight: 600; }
.rate-strip .rate-note {
  color: var(--fg-muted); font-style: normal;
  display: inline-flex; align-items: center; gap: 8px;
}
.rate-strip .rate-note .dot {
  display: inline-block; width: 5px; height: 5px; border-radius: 50%;
  background: var(--accent);
}

.code-body { height: 260px; }
.CodeMirror {
  height: 100% !important;
  font-family: var(--font-mono) !important;
  font-size: 13px !important;
  line-height: 1.55 !important;
  background: var(--paper) !important;
  color: var(--ink-900) !important;
}
.CodeMirror-gutters {
  background: var(--bg-paper) !important;
  border-right: 1px solid var(--border) !important;
}
.CodeMirror-linenumber { color: var(--fg-muted) !important; font-size: 11px !important; }
.CodeMirror .cm-keyword  { color: #8C2A1F; font-weight: 500; }
.CodeMirror .cm-type     { color: #5D3D9F; }
.CodeMirror .cm-number   { color: var(--green-700); }
.CodeMirror .cm-comment  { color: var(--fg-muted); font-style: italic; }
.CodeMirror .cm-string   { color: #0B5D8A; }
.CodeMirror .cm-def      { color: var(--ink-900); font-weight: 500; }
.CodeMirror .CodeMirror-cursor { border-left-color: var(--accent) !important; }

/* ─────────── signals.py workspace ─────────── */
.signals-workspace {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0;
  min-height: 360px;
}
.signals-workspace .sig-left {
  display: flex; flex-direction: column;
  border-right: 1px solid var(--border);
  min-width: 0;
}
.sig-list-row {
  display: flex; align-items: center; gap: 8px;
  padding: 8px 12px;
  background: var(--bg-paper);
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
}
.sig-list { display: flex; gap: 6px; flex-wrap: wrap; flex: 1; min-width: 0; }
.sig-chip {
  display: inline-flex; align-items: center; gap: 7px;
  font-family: var(--font-mono); font-size: 12px;
  padding: 4px 8px 4px 10px;
  border: 1px solid var(--border-strong);
  border-radius: 999px;
  background: var(--paper);
  color: var(--ink-700);
  cursor: pointer;
  transition: border-color 120ms, background 120ms;
}
.sig-chip:hover { border-color: var(--ink-300); }
.sig-chip.active { border-color: var(--accent); background: var(--accent-soft); color: var(--green-700); }
.sig-chip .swatch { width: 9px; height: 9px; border-radius: 2px; display: inline-block; }
.sig-chip .rm {
  border: 0; background: transparent; cursor: pointer;
  color: var(--fg-muted); font-size: 13px; line-height: 1; padding: 0 0 0 2px;
  font-family: var(--font-mono);
}
.sig-chip .rm:hover { color: var(--danger-500); }
.sig-add {
  font-family: var(--font-mono); font-size: 11px;
  text-transform: uppercase; letter-spacing: 0.06em;
  padding: 5px 10px;
  background: var(--paper); color: var(--green-700);
  border: 1px dashed var(--accent); border-radius: var(--radius-2);
  cursor: pointer; white-space: nowrap;
}
.sig-add:hover { background: var(--accent-soft); }
.sig-meta {
  display: flex; align-items: center; gap: 14px;
  padding: 8px 12px; flex-wrap: wrap;
  border-bottom: 1px solid var(--border);
  background: var(--paper);
}
.sig-name-field { display: inline-flex; align-items: center; gap: 8px; }
.sig-name-field span {
  font-family: var(--font-mono); font-size: 10px;
  text-transform: uppercase; letter-spacing: 0.1em; color: var(--fg-soft); font-weight: 600;
}
.sig-name-field input {
  font-family: var(--font-mono); font-size: 13px; font-weight: 600;
  color: var(--green-700);
  background: var(--bg-paper); border: 1px solid var(--border-strong);
  border-radius: 4px; padding: 3px 8px; width: 9em; outline: none;
}
.sig-name-field input:focus { border-color: var(--accent); box-shadow: var(--shadow-focus); }
.sig-deps {
  font-family: var(--font-mono); font-size: 11px; color: var(--fg-muted);
  letter-spacing: 0.02em;
}
.sig-deps code {
  background: var(--bg-inset); padding: 0 4px; border-radius: 3px;
  color: var(--ink-700); margin: 0 1px;
}
.sig-editor { flex: 1; min-height: 240px; }
.sig-editor .CodeMirror { height: 100% !important; }
.sig-right { min-width: 0; display: flex; }
.sig-right .scope-panel { flex: 1; border-top: 0; border-left: 0; border-radius: 0; }
@media (max-width: 820px) {
  .signals-workspace { grid-template-columns: 1fr; }
  .signals-workspace .sig-left { border-right: 0; border-bottom: 1px solid var(--border); }
}

/* ─────────── scope / plot panel ─────────── */
.scope-panel {
  background: var(--code-bg);
  border-radius: var(--radius-3);
  overflow: hidden;
  border-top: 2px solid var(--green-lime);
  box-shadow: var(--shadow-1);
  position: relative;
}
.scope-head {
  display: flex; align-items: center; gap: 14px;
  padding: 10px 14px;
  border-bottom: 1px solid rgba(255,255,255,0.06);
}
.scope-head .scope-title {
  font-family: var(--font-mono); font-size: 11px;
  letter-spacing: 0.14em; text-transform: uppercase;
  color: var(--green-lime); font-weight: 600;
}
.scope-head .scope-readout {
  font-family: var(--font-mono); font-size: 11px;
  color: rgba(230,237,243,0.6); letter-spacing: 0.06em;
}
.scope-body { position: relative; min-height: 340px; }
.scope-canvas { width: 100%; height: 100%; min-height: 340px; }
/* ── Schematic measurement probes ──────────────────────────────────────── */
/* Both sub-layers are hidden (and non-interactive) until a probe mode is on.
   Using display avoids the SVG transparent-fill / pointer-events gotcha. */
.probe-i-layer, .probe-v-layer { display: none; }
.buck-svg.probe-mode-i .probe-i-layer { display: block; }
.buck-svg.probe-mode-v .probe-v-layer { display: block; }
/* Averaged model: duty drives the plant directly — no PWM block/wires, no
   pwm.c tab. The avg-bridge wire is the d→plant shortcut, shown only then. */
.avg-bridge { display: none; }
body.averaged-model .pwm-el { display: none; }
body.averaged-model .avg-bridge { display: inline; }
body.averaged-model .code-tab[data-tab="pwm"] { display: none; }

/* current mode: clickable components get a dashed green highlight so it's clear
   what can be probed; darker on hover. */
.probe-comp {
  fill: rgba(31, 138, 76, 0.10);
  stroke: var(--green-500, #1F8A4C); stroke-width: 1.2; stroke-dasharray: 4 3;
  pointer-events: all; cursor: crosshair;
}
.probe-comp:hover { fill: rgba(31, 138, 76, 0.28); stroke-dasharray: none; }
/* voltage mode: node dots are clearly visible and clickable. */
.probe-node {
  fill: var(--green-500, #1F8A4C); stroke: #fff; stroke-width: 1.5;
  opacity: 0.7; pointer-events: all; cursor: crosshair;
}
.probe-node:hover { opacity: 1; }
.probe-node.pending { opacity: 1; stroke: var(--green-700, #0E5630); stroke-width: 3; }

.meas-panel {
  border: 1px solid var(--line, rgba(0,0,0,0.12));
  border-radius: 10px;
  margin: 0 0 14px;
  padding: 11px 14px;
  background: var(--paper, #fff);
}
.meas-head { display: flex; align-items: baseline; gap: 12px; flex-wrap: wrap; }
.meas-title { font-weight: 600; }
.meas-actions { display: flex; gap: 8px; margin-left: auto; }
.meas-actions .mini.active { background: var(--green-500, #1F8A4C); color: #fff; border-color: var(--green-500, #1F8A4C); }
.meas-hint { font-size: 12px; color: var(--fg-muted, #777); margin: 8px 0 0; }
.meas-list { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 10px; }
.meas-list:empty { display: none; }
.meas-chip {
  display: inline-flex; align-items: center; gap: 7px;
  padding: 3px 6px 3px 8px; border-radius: 999px; font-size: 12px;
  font-family: var(--font-mono, monospace); cursor: pointer; user-select: none;
  border: 1px solid var(--line, rgba(0,0,0,0.16)); background: var(--bg-soft, rgba(0,0,0,0.03));
  color: var(--fg-muted, #777); transition: background 0.1s, color 0.1s, border-color 0.1s;
}
.meas-chip:hover { border-color: var(--green-500, #1F8A4C); }
.meas-chip.on { background: rgba(31,138,76,0.12); border-color: var(--green-500, #1F8A4C); color: var(--ink-900, #1a1a1a); }
.meas-swatch { width: 10px; height: 10px; border-radius: 2px; display: inline-block; border: 1.5px solid; }
.meas-x { border: 0; background: none; cursor: pointer; color: var(--fg-muted, #999); font-size: 12px; line-height: 1; padding: 0 2px; }
.meas-x:hover { color: var(--danger, #c0392b); }

/* ── Plotting guide (docs) ─────────────────────────────────────────────── */
.docs-panel {
  border: 1px solid var(--line, rgba(0,0,0,0.12));
  border-radius: 10px; margin: 0 0 14px; background: var(--paper, #fff); overflow: hidden;
}
.docs-panel > summary {
  cursor: pointer; padding: 11px 14px; list-style: none;
  display: flex; align-items: baseline; gap: 10px; user-select: none; flex-wrap: wrap;
}
.docs-panel > summary::-webkit-details-marker { display: none; }
.docs-panel > summary::before { content: "▸"; opacity: 0.5; font-size: 11px; }
.docs-panel[open] > summary::before { content: "▾"; }
.docs-title { font-weight: 600; }
.docs-hint { font-size: 12px; color: var(--fg-muted, #777); }
.docs-body { padding: 4px 18px 16px; max-width: 900px; font-size: 13.5px; line-height: 1.6; }
.docs-body h4 { margin: 18px 0 6px; font-size: 13.5px; }
.docs-body h4:first-child { margin-top: 6px; }
.docs-body p { margin: 6px 0; }
.docs-body ul { margin: 6px 0 6px; padding-left: 20px; }
.docs-body li { margin: 3px 0; }
.docs-body code { font-family: var(--font-mono, monospace); font-size: 12px; background: var(--bg-soft, rgba(0,0,0,0.04)); padding: 1px 4px; border-radius: 4px; }
.docs-body pre { background: var(--bg-soft, rgba(0,0,0,0.04)); padding: 10px 12px; border-radius: 6px; overflow-x: auto; margin: 8px 0; }
.docs-body pre code { background: none; padding: 0; }

/* ── Parameter sweep panel ─────────────────────────────────────────────── */
.sweep-panel {
  border: 1px solid var(--line, rgba(0,0,0,0.12));
  border-radius: 10px;
  margin: 0 0 14px;
  background: var(--paper, #fff);
  overflow: hidden;
}
.sweep-panel > summary {
  cursor: pointer;
  padding: 12px 14px;
  list-style: none;
  display: flex;
  align-items: center;
  gap: 10px;
  user-select: none;
  background: var(--bg-soft, rgba(0,0,0,0.025));
  transition: background 0.12s ease;
}
.sweep-panel > summary:hover { background: var(--bg-soft, rgba(0,0,0,0.05)); }
.sweep-panel[open] > summary { border-bottom: 1px solid var(--line, rgba(0,0,0,0.1)); }
.sweep-panel > summary::-webkit-details-marker { display: none; }
/* chevron in a clear little box so it reads as a tap-to-expand control */
.sweep-panel > summary::before {
  content: "▸"; display: inline-flex; align-items: center; justify-content: center;
  width: 20px; height: 20px; flex: none; font-size: 12px; line-height: 1;
  color: var(--accent, #166E3D); background: var(--paper, #fff);
  border: 1px solid var(--line, rgba(0,0,0,0.18)); border-radius: 5px;
  transition: transform 0.12s ease;
}
.sweep-panel[open] > summary::before { transform: rotate(90deg); }
.sweep-title { font-weight: 600; }
.sweep-hint { font-size: 12px; color: var(--fg-muted, #777); }
.sweep-hint::after { content: " (click to open)"; }
.sweep-panel[open] .sweep-hint::after { content: ""; }
.sweep-body { padding: 4px 14px 14px; }
.sweep-table { width: 100%; border-collapse: collapse; font-size: 13px; }
.sweep-table th {
  text-align: left; font-weight: 500; font-size: 11px;
  color: var(--fg-muted, #777); padding: 4px 8px; border-bottom: 1px solid var(--line, rgba(0,0,0,0.1));
}
.sweep-table td { padding: 3px 8px; }
.sweep-table tr.sweep-section td {
  padding: 12px 8px 3px; font-size: 10.5px; letter-spacing: 0.06em; text-transform: uppercase;
  font-weight: 600; color: var(--fg-muted, #888); border-bottom: 1px solid var(--line, rgba(0,0,0,0.08));
}
.sweep-table tr.sweep-section:first-child td { padding-top: 2px; }
.sweep-table .sw-name { font-family: var(--font-mono, monospace); white-space: nowrap; }
.sweep-table .sw-unit { color: var(--fg-muted, #999); font-size: 11px; }
.sweep-table input[type=text] {
  width: 72px; padding: 3px 6px; font-family: var(--font-mono, monospace); font-size: 12px;
  border: 1px solid var(--line, rgba(0,0,0,0.18)); border-radius: 5px; background: var(--paper, #fff);
}
.sweep-table input.sw-steps { width: 48px; }
.sweep-table select.sw-space { font-size: 12px; padding: 2px 4px; }
.sweep-foot { display: flex; align-items: center; gap: 14px; margin-top: 12px; }
.sweep-count { font-size: 12px; color: var(--fg-muted, #777); }
.sweep-interp { font-size: 12px; color: var(--fg-muted, #777); display: inline-flex; align-items: center; gap: 5px; cursor: pointer; margin-left: auto; }
.sweep-count.err { color: var(--danger, #c0392b); }
#sweep-run[disabled] { opacity: 0.45; cursor: not-allowed; }

/* Embedded Plot Explorer iframe — height is driven by the embed's content
   (it posts its own height; see app.js), so it flows as part of the page with
   no inner scrollbar. The initial min-height just avoids a zero-height flash. */
.plot-embed {
  width: 100%;
  min-height: 420px;
  border: 0;
  display: block;
  overflow: hidden;
  background: var(--paper, #fff);
}
.scope-empty {
  position: absolute; inset: 0;
  display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  color: rgba(230,237,243,0.4);
  font-family: var(--font-mono); font-size: 12px;
  text-align: center; padding: 32px;
}
.scope-empty .big {
  font-family: var(--font-mono); font-size: 13px;
  color: rgba(230,237,243,0.65);
  letter-spacing: 0.06em; margin-bottom: 8px;
}
.scope-empty .hint { font-size: 11px; max-width: 280px; line-height: 1.55; }
/* #scope-empty overlays the plot-embed IFRAME (its own opaque white document),
   not the dark .scope-panel background that the near-white text above is tuned
   for — give it its own opaque dark backdrop (matches .run-progress) so the
   "no run yet" guidance stays legible regardless of what's under it. */
#scope-empty {
  background: rgba(17,22,26,0.94);
  z-index: 1;
}
#scope-empty .big { color: var(--green-lime); }
#scope-empty .hint { color: rgba(230,237,243,0.75); }
#scope-empty .hint b { color: var(--green-lime); }

.run-progress {
  position: absolute; inset: 0;
  display: flex; flex-direction: column; gap: 14px;
  align-items: center; justify-content: center;
  background: rgba(17,22,26,0.94);
  z-index: 5;
}
.abort-btn {
  background: #7a1f1f; border-color: #a83232; color: #fff;
}
.abort-btn:hover { background: #962626; }
.abort-btn:disabled { opacity: 0.6; cursor: default; }
.run-progress-inner {
  font-family: var(--font-mono); color: var(--green-lime);
  font-size: 13px; letter-spacing: 0.08em;
}
.run-progress-inner .dots::after {
  content: ''; display: inline-block; animation: dots 800ms steps(4, end) infinite;
}
@keyframes dots {
  0%,25%   { content: ''; }
  26%,50%  { content: '.'; }
  51%,75%  { content: '..'; }
  76%,100% { content: '...'; }
}

/* ─────────── signal selector (above plot) ─────────── */
.signal-checks { display: flex; gap: 4px; flex-wrap: wrap; margin-bottom: 14px; }
.signal-checks label {
  display: inline-flex; align-items: center; gap: 6px;
  font-family: var(--font-mono); font-size: 12px;
  padding: 4px 10px;
  border: 1px solid var(--border-strong);
  border-radius: 999px;
  background: var(--paper);
  cursor: pointer;
  transition: border-color 120ms, background 120ms;
}
.signal-checks label:has(input:checked) {
  border-color: var(--accent);
  background: var(--accent-soft);
  color: var(--green-700);
}
.signal-checks input { accent-color: var(--accent); }
.signal-checks .swatch {
  display: inline-block; width: 10px; height: 3px; border-radius: 1px;
}

/* ─────────── footnote ─────────── */
.footnote {
  font-family: var(--font-mono); font-size: 11px;
  color: var(--fg-muted); letter-spacing: 0.04em;
  margin: 16px 0 0;
}

/* ─────────── site footer ─────────── */
footer.site {
  border-top: 1px solid var(--border);
  background: var(--ink-50);
  padding: 40px 22px 32px;
  margin-top: 40px;
}
footer.site .inner {
  max-width: var(--wide-max); margin: 0 auto;
  display: grid; grid-template-columns: 1.6fr 1fr 1fr 1fr; gap: 32px;
}
footer.site h4 {
  font-family: var(--font-sans); font-size: 11px;
  font-weight: 600; text-transform: uppercase; letter-spacing: 0.08em;
  color: var(--ink-900); margin: 0 0 12px;
}
footer.site ul { list-style: none; padding: 0; margin: 0; }
footer.site li { margin-bottom: 8px; }
footer.site a { color: var(--fg-soft); text-decoration: none; font-size: 13.5px; }
footer.site a:hover { color: var(--accent); }
footer.site p { font-size: 13.5px; color: var(--fg-soft); line-height: 1.55; margin: 0; }
footer.site .cp { margin-top: 18px; font-size: 12px; color: var(--fg-muted); }
.brandfoot { display: flex; align-items: center; gap: 10px; margin-bottom: 12px; }
.brandfoot img { height: 38px; width: auto; }
.brandfoot .name { font-family: var(--font-serif); font-weight: 600; color: var(--ink-900); font-size: 16px; }
@media (max-width: 760px) {
  footer.site .inner { grid-template-columns: 1fr 1fr; }
}

/* ── site header — mobile nav toggle (mirrors main site Header.astro) ── */
.nav-toggle { display: none; flex-direction: column; justify-content: center; gap: 5px; width: 42px; height: 42px; margin-left: auto; padding: 9px; background: transparent; border: 1px solid var(--border); border-radius: var(--radius-2); cursor: pointer; }
.nav-toggle .bar { display: block; height: 2px; width: 100%; background: var(--ink-900); border-radius: 2px; transition: transform .15s ease, opacity .15s; }
header.site.nav-open .nav-toggle .bar:nth-child(1) { transform: translateY(7px) rotate(45deg); }
header.site.nav-open .nav-toggle .bar:nth-child(2) { opacity: 0; }
header.site.nav-open .nav-toggle .bar:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }
header.site nav a[aria-current=page] { border-bottom-color: var(--accent); color: var(--accent); }
@media (max-width: 720px) {
  .nav-toggle { display: flex; }
  header.site .inner { flex-wrap: wrap; gap: 10px; }
  header.site nav { display: none; flex-basis: 100%; flex-direction: column; gap: 0; margin: 0 0 6px; }
  header.site.nav-open nav { display: flex; }
  header.site nav a { padding: 12px 2px; font-size: 16px; border-bottom: 1px solid var(--border); }
  header.site nav a:first-child { border-top: 1px solid var(--border); }
  header.site nav a[aria-current=page] { color: var(--accent); border-bottom-color: var(--border); }
}

/* C-source line a run error mapped to (cleared on edit / next run) */
.cm-errorline { background: rgba(168, 50, 74, 0.16) !important; }

/* ── Mobile schematic / block-diagram legibility ─────────────────────────
   Both figures scale linearly with width:100% and no floor, so on a phone
   the value readouts and block sublabels shrink to ~4-5px and become
   unreadable. Give the SVGs a real minimum size and let the frame that
   holds them scroll horizontally (same idea as a swipeable strip) instead
   of shrinking the drawing past legibility. */
@media (max-width: 480px) {
  .schematic-frame, .diagram-frame {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
  }
  .buck-svg { width: auto; min-width: 620px; max-height: none; }
  .block-svg { width: auto; min-width: 640px; max-height: none; }

  /* fig. 1 / fig. 2 caption + D_ss readout: at ~390px the caption used to
     wrap onto the same visual line as the right-aligned D_ss cell,
     producing interleaved garbled text. Stack them instead. */
  .schematic-frame .schematic-meta,
  .diagram-frame .schematic-meta {
    flex-direction: column;
    align-items: flex-start;
    gap: 2px;
  }
}
.btn#pin-btn.pinned { background: var(--accent); color: #fff; border-color: var(--accent); }