/* =========================================================================
   BRAND BUDGET CALCULATOR — Studio Nine
   Visual language: Teenage Engineering-style instrument panel.
   Mono everywhere on the interface. Hard edges, screen-printed labels,
   coloured rivets, an LCD-style display. Cream chassis, lime accent.
   ========================================================================= */

/* Local design tokens. */
.s9-bbc {
  --bbc-chassis: #efedea;
  --bbc-chassis-edge: #cdc8be;
  --bbc-screen: #0a0a0a;
  --bbc-screen-ink: #d4ff3f;   /* lime LCD */
  --bbc-screen-dim: rgba(212, 255, 63, 0.25);
  --bbc-ink: #0a0a0a;
  --bbc-mute: #6b6b6b;
  --bbc-rivet: #b0a99c;
  --bbc-accent: #ff5a1f;       /* TE-orange — used sparingly as functional accent */
  --bbc-accent-2: #d4ff3f;     /* studio nine lime — primary */
  --bbc-rule: rgba(10,10,10,0.12);
  --bbc-rule-strong: rgba(10,10,10,0.28);
  --bbc-radius: 4px;           /* near-zero radius — TE is angular */
  --bbc-radius-lg: 8px;
  --bbc-mono: 'Geist Mono', ui-monospace, monospace;
}

.s9-bbc {
  padding-top: calc(var(--s9-header-h) + clamp(3rem, 6vw, 6rem));
  padding-bottom: clamp(4rem, 8vw, 8rem);
}

/* -------- INTRO ROW -------- */
.s9-bbc__meta-row {
  display: flex;
  align-items: center;
  gap: 1rem;
  font-family: var(--bbc-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--bbc-mute);
  margin-bottom: 1.25rem;
}
.s9-bbc__device-id {
  padding: 4px 10px;
  border: 1px solid var(--bbc-rule-strong);
  border-radius: 999px;
  background: rgba(255,255,255,0.4);
}
/* Rev tile sits inline with the other meta pills (was pushed to the far
   right via margin-left:auto, which read as a stray floating chip). */
.s9-bbc__device-status {
  display: inline-flex; align-items: center; gap: .5rem;
  color: var(--bbc-ink);
}
.s9-bbc__led {
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--bbc-accent);
  box-shadow: 0 0 0 1px rgba(255, 90, 31, 0.25), 0 0 12px rgba(255, 90, 31, 0.55);
  animation: bbc-blink 1.6s infinite;
}
.s9-bbc__led.is-ready    { background: var(--bbc-accent-2); box-shadow: 0 0 0 1px rgba(212, 255, 63, 0.35), 0 0 14px rgba(212, 255, 63, 0.55); animation: none; }
.s9-bbc__led.is-computing{ background: var(--bbc-accent); animation: bbc-blink 0.4s infinite; }
@keyframes bbc-blink { 0%, 100% { opacity: 1; } 50% { opacity: 0.35; } }

.s9-bbc__title {
  font-family: var(--s9-font-display);
  font-weight: 700;
  font-size: clamp(2.5rem, 6vw, 4.5rem);
  line-height: 1.04;
  letter-spacing: -0.03em;
  padding-block: 0.06em;
  margin: 0 0 1rem;
  max-width: 16ch;
}
.s9-bbc__title em {
  font-family: var(--s9-font-serif);
  font-style: italic;
  font-weight: 400;
  color: var(--s9-accent-text);
}
.s9-bbc__lead {
  font-size: var(--s9-size-xl);
  line-height: 1.45;
  color: var(--s9-fg-mute);
  max-width: 60ch;
  margin: 0 0 clamp(2.5rem, 5vw, 4rem);
}
.s9-bbc__lead a { color: var(--bbc-ink); border-bottom: 1px solid var(--bbc-rule-strong); }
.s9-bbc__head { max-width: 920px; }

/* -------- BACK LINK -------- */
/* Sits above the tool header on every /tools/* page, returning to /tools.
   Styled to match the chassis meta pills — mono, uppercase, hairline border. */
.s9-bbc__back {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  font-family: var(--bbc-mono);
  font-size: 0.7rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--bbc-mute);
  text-decoration: none;
  padding: 6px 12px 6px 10px;
  border: 1px solid var(--bbc-rule-strong);
  border-radius: 999px;
  background: rgba(255,255,255,0.4);
  margin-bottom: clamp(1.5rem, 3vw, 2.5rem);
  transition: color 160ms ease, background-color 160ms ease, transform 160ms ease, border-color 160ms ease;
}
.s9-bbc__back:hover {
  color: var(--bbc-ink);
  background: rgba(255,255,255,0.85);
  border-color: var(--bbc-ink);
  transform: translateX(-2px);
}
.s9-bbc__back-arrow {
  display: inline-block;
  transition: transform 160ms ease;
}
.s9-bbc__back:hover .s9-bbc__back-arrow {
  transform: translateX(-2px);
}

/* -------- THE DEVICE -------- */
.s9-bbc__device {
  background: var(--bbc-chassis);
  border: 1px solid var(--bbc-chassis-edge);
  border-radius: var(--bbc-radius-lg);
  box-shadow:
    inset 0 1px 0 rgba(255,255,255,0.5),
    inset 0 -1px 0 rgba(0,0,0,0.05),
    0 1px 0 rgba(255,255,255,0.6),
    0 30px 60px -30px rgba(0,0,0,0.18),
    0 12px 24px -12px rgba(0,0,0,0.12);
  position: relative;
  overflow: hidden;
}
/* Subtle screw-printed grid texture, very faint */
.s9-bbc__device::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(10,10,10,0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(10,10,10,0.025) 1px, transparent 1px);
  background-size: 22px 22px;
  pointer-events: none;
  z-index: 0;
}
.s9-bbc__device-inner {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1fr 8px 1fr;
  gap: 0;
  padding: clamp(1.25rem, 2.5vw, 2rem);
}
@media (max-width: 900px) {
  .s9-bbc__device-inner { grid-template-columns: 1fr; }
}

/* Corner rivets — appear as small dots in each corner of the device */
.s9-bbc__device::after {
  content: "";
  position: absolute;
  inset: 14px;
  border: 1px dashed rgba(10, 10, 10, 0.08);
  border-radius: var(--bbc-radius);
  pointer-events: none;
  z-index: 0;
}

/* -------- PANELS -------- */
.s9-bbc__panel {
  background: transparent;
  padding: clamp(1rem, 1.6vw, 1.4rem);
  position: relative;
  z-index: 1;
}
.s9-bbc__panel--inputs { display: flex; flex-direction: column; gap: clamp(1.5rem, 2vw, 2rem); }

/* Vertical divider with rivets */
.s9-bbc__divider {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: space-around;
  padding: 0 0;
  z-index: 1;
}
.s9-bbc__divider::before {
  content: "";
  position: absolute;
  top: 16px; bottom: 16px; left: 50%;
  width: 1px;
  background: var(--bbc-rule-strong);
  transform: translateX(-50%);
}
.s9-bbc__divider > span {
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--bbc-rivet);
  box-shadow:
    inset 0 1px 0 rgba(255,255,255,0.4),
    inset 0 -1px 0 rgba(0,0,0,0.15),
    0 1px 1px rgba(0,0,0,0.1);
  position: relative;
  z-index: 1;
}
@media (max-width: 900px) {
  .s9-bbc__divider { flex-direction: row; padding: 1rem 0; }
  .s9-bbc__divider::before { top: 50%; left: 16px; right: 16px; bottom: auto; width: auto; height: 1px; transform: translateY(-50%); }
}

/* -------- FIELDS -------- */
.s9-bbc__field {
  border: 0;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: .65rem;
}
.s9-bbc__field legend {
  display: flex;
  align-items: baseline;
  gap: .65rem;
  font-family: var(--s9-font-display);
  font-weight: 600;
  font-size: 1.125rem;
  letter-spacing: -0.015em;
  padding: 0;
  margin-bottom: 0;
}
.s9-bbc__field-num {
  font-family: var(--bbc-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  font-weight: 600;
  color: var(--bbc-accent);
  background: rgba(255, 90, 31, 0.08);
  padding: 3px 8px;
  border-radius: 3px;
  border: 1px solid rgba(255, 90, 31, 0.25);
}
.s9-bbc__field-hint {
  font-family: var(--bbc-mono);
  font-size: 12px;
  color: var(--bbc-mute);
  letter-spacing: 0.02em;
  margin: 0;
}
.s9-bbc__field-hint--small { font-size: 11px; margin-top: .35rem; }
.s9-bbc__field-hint--small strong { color: var(--bbc-ink); font-weight: 600; }
.s9-bbc__field-hint--small[hidden] { display: none; }

/* Money / pct input row */
.s9-bbc__row {
  display: flex;
  align-items: stretch;
  border: 1px solid var(--bbc-rule-strong);
  border-radius: var(--bbc-radius);
  overflow: hidden;
  background: #fff;
  box-shadow: inset 0 1px 2px rgba(0,0,0,0.04);
}
.s9-bbc__row:focus-within {
  border-color: var(--bbc-ink);
  box-shadow: inset 0 1px 2px rgba(0,0,0,0.04), 0 0 0 2px var(--bbc-accent-2);
}
.s9-bbc__prefix, .s9-bbc__suffix {
  display: inline-flex;
  align-items: center;
  padding: 0 .9rem;
  font-family: var(--bbc-mono);
  font-size: 14px;
  color: var(--bbc-mute);
  background: rgba(0,0,0,0.04);
  border-right: 1px solid var(--bbc-rule);
}
.s9-bbc__suffix { border-right: 0; border-left: 1px solid var(--bbc-rule); }
.s9-bbc__row input {
  flex: 1;
  min-width: 0;
  padding: .75rem .85rem;
  border: 0;
  background: transparent;
  font: inherit;
  font-family: var(--bbc-mono);
  font-size: 16px;
  letter-spacing: 0.02em;
  color: var(--bbc-ink);
  outline: none;
}
.s9-bbc__row select {
  border: 0;
  background: transparent;
  border-left: 1px solid var(--bbc-rule);
  padding: 0 .8rem;
  font: inherit;
  font-family: var(--bbc-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--bbc-ink);
  cursor: pointer;
}
.s9-bbc__row--pct input { text-align: right; padding-right: 0; }

/* Slider — chunky, instrument-feel */
.s9-bbc__slider-wrap {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 1rem;
  align-items: center;
  padding: .9rem 1rem;
  background: #fff;
  border: 1px solid var(--bbc-rule-strong);
  border-radius: var(--bbc-radius);
}
.s9-bbc__slider {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 6px;
  background: linear-gradient(to right,
    rgba(212,255,63,0.5) 0%,
    var(--bbc-accent-2) 30%,
    var(--bbc-accent-2) 60%,
    var(--bbc-accent) 100%);
  border-radius: 999px;
  outline: none;
  cursor: pointer;
}
.s9-bbc__slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 22px; height: 22px;
  border-radius: 50%;
  background: var(--bbc-ink);
  border: 3px solid #fff;
  box-shadow: 0 1px 3px rgba(0,0,0,0.3), 0 0 0 1px rgba(0,0,0,0.5);
  cursor: grab;
  transition: transform 120ms;
}
.s9-bbc__slider::-webkit-slider-thumb:active { transform: scale(1.15); cursor: grabbing; }
.s9-bbc__slider::-moz-range-thumb {
  width: 22px; height: 22px;
  border-radius: 50%;
  background: var(--bbc-ink);
  border: 3px solid #fff;
  box-shadow: 0 1px 3px rgba(0,0,0,0.3), 0 0 0 1px rgba(0,0,0,0.5);
  cursor: grab;
}
.s9-bbc__slider-out {
  display: inline-flex;
  align-items: baseline;
  gap: 2px;
  font-family: var(--bbc-mono);
  background: #0a0a0a;
  color: var(--bbc-screen-ink);
  padding: 6px 12px;
  border-radius: 3px;
  font-weight: 600;
  min-width: 80px;
  justify-content: center;
}
.s9-bbc__digit { font-variant-numeric: tabular-nums; font-size: 16px; }
.s9-bbc__digit-unit { font-size: 11px; opacity: 0.7; }

/* Choices — like instrument selector pads */
.s9-bbc__choices {
  display: flex;
  flex-direction: column;
  gap: 0;
  border: 1px solid var(--bbc-rule-strong);
  border-radius: var(--bbc-radius);
  background: #fff;
  overflow: hidden;
}
.s9-bbc__choice {
  display: grid;
  grid-template-columns: 32px 1fr;
  grid-template-rows: auto auto;
  gap: 0 .85rem;
  padding: .7rem .9rem;
  cursor: pointer;
  border-bottom: 1px solid var(--bbc-rule);
  transition: background var(--s9-d-fast) var(--s9-ease);
  position: relative;
}
.s9-bbc__choice:last-child { border-bottom: 0; }
.s9-bbc__choice:hover { background: rgba(0,0,0,0.025); }
.s9-bbc__choice input { position: absolute; opacity: 0; pointer-events: none; }
.s9-bbc__choice-key {
  grid-row: 1 / span 2;
  align-self: center;
  display: inline-flex;
  align-items: center; justify-content: center;
  width: 28px; height: 28px;
  background: rgba(0,0,0,0.04);
  border: 1px solid var(--bbc-rule);
  border-radius: 3px;
  font-family: var(--bbc-mono);
  font-weight: 600;
  font-size: 12px;
  color: var(--bbc-mute);
}
.s9-bbc__choice-title {
  font-weight: 600;
  font-size: 14px;
  color: var(--bbc-ink);
}
.s9-bbc__choice-sub {
  font-family: var(--bbc-mono);
  font-size: 11.5px;
  color: var(--bbc-mute);
  letter-spacing: 0.01em;
  line-height: 1.4;
}
.s9-bbc__choice:has(input:checked) {
  background: rgba(212, 255, 63, 0.12);
}
.s9-bbc__choice:has(input:checked) .s9-bbc__choice-key {
  background: var(--bbc-accent-2);
  border-color: var(--bbc-accent-2);
  color: var(--bbc-ink);
}
.s9-bbc__choice:has(input:focus-visible) {
  outline: 2px solid var(--bbc-accent-2);
  outline-offset: -2px;
}

/* -------- DISPLAY PANEL -------- */
.s9-bbc__panel--display { display: flex; flex-direction: column; gap: 1.25rem; }

.s9-bbc__display-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  padding-bottom: .65rem;
  border-bottom: 1px dashed var(--bbc-rule);
}
.s9-bbc__display-label {
  font-family: var(--bbc-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--bbc-mute);
}
.s9-bbc__display-sub {
  font-family: var(--bbc-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--bbc-ink);
  background: rgba(0,0,0,0.06);
  padding: 3px 8px;
  border-radius: 3px;
}

/* LCD readout — black screen, lime ink, like an OP-1 main display */
.s9-bbc__lcd {
  background: #0a0a0a;
  color: var(--bbc-screen-ink);
  padding: 1.5rem 1.25rem 1.25rem;
  border-radius: var(--bbc-radius);
  border: 1px solid #000;
  box-shadow:
    inset 0 1px 0 rgba(255,255,255,0.05),
    inset 0 0 0 1px rgba(212,255,63,0.06),
    0 1px 2px rgba(0,0,0,0.2);
  position: relative;
  overflow: hidden;
}
/* Faint scanlines for the LCD feel */
.s9-bbc__lcd::before {
  content: "";
  position: absolute;
  inset: 0;
  background: repeating-linear-gradient(
    to bottom,
    transparent 0px,
    transparent 3px,
    rgba(255,255,255,0.02) 3px,
    rgba(255,255,255,0.02) 4px
  );
  pointer-events: none;
}
.s9-bbc__lcd-range {
  display: flex;
  align-items: baseline;
  justify-content: center;
  gap: .75rem;
  font-family: var(--bbc-mono);
  font-weight: 600;
  font-size: clamp(2.25rem, 5vw, 3.25rem);
  letter-spacing: -0.02em;
  line-height: 1;
  font-variant-numeric: tabular-nums;
  text-shadow: 0 0 18px rgba(212, 255, 63, 0.45);
}
.s9-bbc__lcd-sep { opacity: 0.45; font-weight: 400; }
.s9-bbc__lcd-pct {
  display: flex;
  align-items: baseline;
  justify-content: center;
  gap: .65rem;
  margin-top: .65rem;
  font-family: var(--bbc-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--bbc-screen-ink);
  opacity: 0.85;
}
.s9-bbc__lcd-unit { font-size: 10.5px; letter-spacing: 0.18em; opacity: 0.6; }
/* "YOU" line — shows the user's current spend in absolute terms below the
   recommended range. Same LCD-style typography, dimmer so the recommended
   range stays the primary read. */
.s9-bbc__lcd-current {
  display: flex;
  align-items: baseline;
  justify-content: center;
  gap: .65rem;
  margin-top: 1rem;
  padding-top: .85rem;
  border-top: 1px dashed rgba(212, 255, 63, 0.18);
  font-family: var(--bbc-mono);
  font-size: 13px;
  letter-spacing: 0.04em;
  position: relative;
}
.s9-bbc__lcd-current-label {
  font-size: 10.5px;
  letter-spacing: 0.18em;
  opacity: 0.55;
  font-weight: 600;
}
.s9-bbc__lcd-current-amt {
  font-size: 18px;
  font-weight: 600;
  color: var(--bbc-screen-ink);
  font-variant-numeric: tabular-nums;
}
.s9-bbc__lcd-current-pct {
  font-size: 11.5px;
  opacity: 0.6;
}
/* Brief brighten when values change — like an instrument refresh. */
.s9-bbc__lcd.is-pulsing { animation: bbc-lcd-pulse 220ms cubic-bezier(0.2, 0.8, 0.2, 1); }
@keyframes bbc-lcd-pulse {
  0%   { box-shadow: inset 0 1px 0 rgba(255,255,255,0.05), inset 0 0 0 1px rgba(212,255,63,0.06), 0 1px 2px rgba(0,0,0,0.2); }
  50%  { box-shadow: inset 0 1px 0 rgba(255,255,255,0.05), inset 0 0 30px rgba(212,255,63,0.18), 0 1px 2px rgba(0,0,0,0.2); }
  100% { box-shadow: inset 0 1px 0 rgba(255,255,255,0.05), inset 0 0 0 1px rgba(212,255,63,0.06), 0 1px 2px rgba(0,0,0,0.2); }
}

/* RANGE BAR — visualises where current spend sits within the recommended zone */
.s9-bbc__bar { padding: 0 .25rem; }
.s9-bbc__bar-track {
  position: relative;
  height: 38px;
  background: rgba(0,0,0,0.04);
  border: 1px solid var(--bbc-rule);
  border-radius: 3px;
}
.s9-bbc__bar-zone {
  position: absolute;
  top: 0; bottom: 0;
  background: var(--bbc-accent-2);
  border-left: 2px solid var(--bbc-ink);
  border-right: 2px solid var(--bbc-ink);
  transition: left 400ms cubic-bezier(0.2, 0.8, 0.2, 1), width 400ms cubic-bezier(0.2, 0.8, 0.2, 1);
}
.s9-bbc__bar-marker {
  position: absolute;
  top: -6px; bottom: -6px;
  width: 2px;
  background: var(--bbc-ink);
  transform: translateX(-50%);
  transition: left 220ms cubic-bezier(0.2, 0.8, 0.2, 1);
}
.s9-bbc__bar-marker::before, .s9-bbc__bar-marker::after {
  content: "";
  position: absolute;
  left: 50%; transform: translateX(-50%);
  width: 0; height: 0;
  border-left: 5px solid transparent;
  border-right: 5px solid transparent;
}
.s9-bbc__bar-marker::before { top: -1px; border-top: 6px solid var(--bbc-ink); }
.s9-bbc__bar-marker::after  { bottom: -1px; border-bottom: 6px solid var(--bbc-ink); }
.s9-bbc__bar-flag {
  position: absolute;
  top: -32px;
  left: 50%;
  transform: translateX(-50%);
  font-family: var(--bbc-mono);
  font-size: 11px;
  font-weight: 600;
  background: var(--bbc-ink);
  color: #fff;
  padding: 3px 8px;
  border-radius: 3px;
  white-space: nowrap;
  letter-spacing: 0.02em;
}
.s9-bbc__bar-flag::after {
  content: "";
  position: absolute;
  bottom: -4px; left: 50%;
  transform: translateX(-50%);
  width: 0; height: 0;
  border-left: 4px solid transparent;
  border-right: 4px solid transparent;
  border-top: 4px solid var(--bbc-ink);
}
.s9-bbc__bar-axis {
  display: flex;
  justify-content: space-between;
  margin-top: .55rem;
  font-family: var(--bbc-mono);
  font-size: 10.5px;
  letter-spacing: 0.06em;
  color: var(--bbc-mute);
}

/* VERDICT */
.s9-bbc__verdict {
  padding: .75rem .85rem;
  border: 1px solid var(--bbc-rule);
  border-left: 3px solid var(--bbc-mute);
  border-radius: 3px;
  background: rgba(0,0,0,0.025);
}
.s9-bbc__verdict[data-bbc-verdict-state="under"]  { border-left-color: var(--bbc-accent); background: rgba(255, 90, 31, 0.05); }
.s9-bbc__verdict[data-bbc-verdict-state="over"]   { border-left-color: #3498db;        background: rgba(52, 152, 219, 0.05); }
.s9-bbc__verdict[data-bbc-verdict-state="in"]     { border-left-color: var(--bbc-accent-2); background: rgba(212, 255, 63, 0.08); }
.s9-bbc__verdict-label {
  font-family: var(--bbc-mono);
  font-size: 10.5px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--bbc-mute);
  margin: 0 0 .25rem;
}
.s9-bbc__verdict-msg {
  font-family: var(--bbc-mono);
  font-size: 13.5px;
  font-weight: 500;
  color: var(--bbc-ink);
  line-height: 1.45;
  margin: 0;
}

/* WHY */
.s9-bbc__why { font-family: var(--bbc-mono); }
.s9-bbc__why summary {
  cursor: pointer;
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--bbc-mute);
  list-style: none;
  padding: .5rem 0;
}
.s9-bbc__why summary::-webkit-details-marker { display: none; }
.s9-bbc__why summary::before { content: "[+] "; color: var(--bbc-accent); margin-right: 2px; }
.s9-bbc__why[open] summary::before { content: "[−] "; }
.s9-bbc__why p {
  font-family: 'Inter', sans-serif;
  font-size: 13.5px;
  line-height: 1.55;
  color: var(--bbc-mute);
  margin: 0 0 .5rem;
}

/* ACTION BUTTONS — instrument toggles */
.s9-bbc__actions {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem;
  padding-top: .75rem;
  border-top: 1px dashed var(--bbc-rule);
}
.s9-bbc__action {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: .6rem 1rem;
  border: 1px solid var(--bbc-rule-strong);
  border-radius: 3px;
  background: #fff;
  font-family: var(--bbc-mono);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--bbc-ink);
  cursor: pointer;
  text-decoration: none;
  transition: background var(--s9-d-fast) var(--s9-ease), transform var(--s9-d-fast) var(--s9-ease);
}
.s9-bbc__action:hover { background: rgba(0,0,0,0.04); }
.s9-bbc__action:active { transform: translateY(1px); }
.s9-bbc__action--primary {
  background: var(--bbc-accent-2);
  border-color: var(--bbc-accent-2);
}
.s9-bbc__action--primary:hover { filter: brightness(0.94); }

/* SAVE-BY-EMAIL block (optional capture; no gate on the tool itself). */
.s9-bbc__save {
  margin-top: .75rem;
  padding: .9rem 1rem;
  background: rgba(0,0,0,0.025);
  border: 1px dashed var(--bbc-rule-strong);
  border-radius: 3px;
}
.s9-bbc__save-label {
  margin: 0 0 .6rem;
  font-family: var(--bbc-mono);
  font-size: 10.5px;
  font-weight: 600;
  letter-spacing: 0.16em;
  color: var(--bbc-mute);
}
.s9-bbc__save-row {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: .4rem;
  align-items: stretch;
}
.s9-bbc__save-row input[type="email"] {
  padding: .55rem .7rem;
  border: 1px solid var(--bbc-rule-strong);
  border-radius: 3px;
  background: #fff;
  font: inherit;
  font-family: var(--bbc-mono);
  font-size: 13px;
  color: var(--bbc-ink);
  outline: none;
}
.s9-bbc__save-row input[type="email"]:focus { border-color: var(--bbc-ink); box-shadow: 0 0 0 2px var(--bbc-accent-2); }
.s9-bbc__save-row button { padding: 0 1rem; }

.s9-bbc__save-check {
  display: flex; align-items: flex-start; gap: .55rem;
  margin-top: .6rem;
  font-family: var(--bbc-mono);
  font-size: 11.5px;
  line-height: 1.45;
  color: var(--bbc-mute);
  cursor: pointer;
}
.s9-bbc__save-check input { margin-top: 2px; flex-shrink: 0; accent-color: var(--bbc-ink); }

.s9-bbc__save-status {
  margin: .6rem 0 0;
  font-family: var(--bbc-mono);
  font-size: 11px;
  letter-spacing: 0.04em;
  min-height: 1.2em;
}
.s9-bbc__save-status:empty { display: none; }
.s9-bbc__save-status.is-ok   { color: #1f6b3a; }
.s9-bbc__save-status.is-err  { color: #a82a1f; }
.s9-bbc__save-status.is-pending { color: var(--bbc-mute); }

/* -------- DEVICE FOOT (branding) -------- */
.s9-bbc__device-foot {
  position: relative; z-index: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  padding: .75rem 1rem 1rem;
  border-top: 1px dashed var(--bbc-rule);
  margin: 0 clamp(1rem, 2.5vw, 1.75rem);
  font-family: var(--bbc-mono);
  font-size: 10.5px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--bbc-mute);
}
.s9-bbc__device-foot-divider {
  width: 4px; height: 4px; border-radius: 50%; background: var(--bbc-rivet);
}

/* -------- "UNDER THE HOOD" DISCLOSURE — spec-sheet panel --------
   Designed to feel like a second instrument: same chassis material as
   the calculator above but tagged "SPEC SHEET" with a tighter, more
   schematic typography. Spans the full container width, sits as a
   self-contained block rather than a thin underline. */
.s9-bbc__math {
  margin-top: clamp(2.5rem, 4vw, 3.5rem);
  width: 100%;
}
.s9-bbc__math > details {
  background: var(--bbc-chassis);
  border: 1px solid var(--bbc-chassis-edge);
  border-radius: var(--bbc-radius-lg);
  box-shadow:
    inset 0 1px 0 rgba(255,255,255,0.5),
    inset 0 -1px 0 rgba(0,0,0,0.05),
    0 1px 0 rgba(255,255,255,0.6),
    0 18px 36px -24px rgba(0,0,0,0.16),
    0 8px 16px -10px rgba(0,0,0,0.1);
  position: relative;
  overflow: hidden;
}
.s9-bbc__math > details::before {
  /* same screw-printed grid texture as the device chassis */
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(10,10,10,0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(10,10,10,0.025) 1px, transparent 1px);
  background-size: 22px 22px;
  pointer-events: none;
  z-index: 0;
}

/* Summary header — reads like a control bar at the top of a panel */
.s9-bbc__math summary {
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: clamp(1rem, 2vw, 1.25rem) clamp(1.25rem, 2.5vw, 1.75rem);
  list-style: none;
  position: relative;
  z-index: 1;
  border-bottom: 1px solid transparent;
  transition: border-color var(--s9-d-fast) var(--s9-ease), background var(--s9-d-fast) var(--s9-ease);
}
.s9-bbc__math summary::-webkit-details-marker { display: none; }
.s9-bbc__math summary:hover { background: rgba(0,0,0,0.025); }
.s9-bbc__math[open] summary { border-bottom-color: var(--bbc-rule); }

/* Eyebrow tag — uses the same device-id pill language */
.s9-bbc__math summary::before {
  content: "SPEC";
  font-family: var(--bbc-mono);
  font-size: 10.5px;
  font-weight: 600;
  letter-spacing: 0.18em;
  color: var(--bbc-accent);
  background: rgba(255, 90, 31, 0.08);
  border: 1px solid rgba(255, 90, 31, 0.3);
  padding: 4px 9px;
  border-radius: 3px;
  white-space: nowrap;
  flex-shrink: 0;
}

/* The 'Under the hood…' text itself */
.s9-bbc__math summary {
  font-family: var(--s9-font-display);
  font-weight: 600;
  font-size: clamp(1.125rem, 1.6vw, 1.35rem);
  letter-spacing: -0.015em;
  color: var(--bbc-ink);
  text-transform: none;
}

/* Right-side toggle indicator — replaces the bare [+]/[−] */
.s9-bbc__math summary::after {
  content: "OPEN ⌄";
  margin-left: auto;
  font-family: var(--bbc-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.14em;
  color: var(--bbc-mute);
  background: #fff;
  border: 1px solid var(--bbc-rule-strong);
  padding: 5px 11px;
  border-radius: 3px;
  white-space: nowrap;
  transition: background var(--s9-d-fast) var(--s9-ease), color var(--s9-d-fast) var(--s9-ease);
}
.s9-bbc__math summary:hover::after { background: var(--bbc-ink); color: var(--bbc-chassis); border-color: var(--bbc-ink); }
.s9-bbc__math[open] summary::after { content: "CLOSE ⌃"; background: var(--bbc-ink); color: var(--bbc-chassis); border-color: var(--bbc-ink); }

/* Body content — sits beneath the header bar */
.s9-bbc__math > details > div {
  padding: clamp(1.25rem, 2.5vw, 1.75rem) clamp(1.25rem, 2.5vw, 1.75rem) clamp(1.5rem, 3vw, 2rem);
  position: relative;
  z-index: 1;
  max-width: none;
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(.75rem, 1.5vw, 1rem);
}
@media (min-width: 760px) {
  .s9-bbc__math > details > div { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: clamp(1rem, 2vw, 1.5rem) clamp(2rem, 3vw, 2.5rem); }
  /* List and trailing notes span both columns for readability */
  .s9-bbc__math > details > div > ul,
  .s9-bbc__math > details > div > p:last-child,
  .s9-bbc__math > details > div > p:nth-last-child(2) { grid-column: 1 / -1; }
}

.s9-bbc__math p {
  font-size: 15px;
  line-height: 1.6;
  color: var(--bbc-ink);
  margin: 0;
}
.s9-bbc__math p + p { margin-top: .25rem; }

/* The numbered/bulleted list of category ranges or score weights */
.s9-bbc__math ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: .35rem;
  border: 1px solid var(--bbc-rule);
  border-radius: var(--bbc-radius);
  background: rgba(255,255,255,0.5);
  overflow: hidden;
}
.s9-bbc__math li {
  display: grid;
  grid-template-columns: minmax(160px, 22%) 1fr;
  gap: 1.25rem;
  align-items: baseline;
  padding: .65rem .9rem;
  font-size: 14.5px;
  line-height: 1.55;
  color: var(--bbc-mute);
  border-bottom: 1px solid var(--bbc-rule);
}
.s9-bbc__math li:last-child { border-bottom: 0; }
.s9-bbc__math li strong {
  color: var(--bbc-ink);
  font-weight: 600;
  font-family: var(--bbc-mono);
  font-size: 12.5px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
@media (max-width: 540px) {
  .s9-bbc__math li { grid-template-columns: 1fr; gap: .2rem; }
}

.s9-bbc__math code {
  background: rgba(10,10,10,0.06);
  padding: 1px 5px;
  border-radius: 3px;
  font-family: var(--bbc-mono);
  font-size: .9em;
  color: var(--bbc-ink);
}
.s9-bbc__math em { font-family: var(--s9-font-serif); font-style: italic; color: var(--bbc-ink); }
.s9-bbc__math strong { color: var(--bbc-ink); }
.s9-bbc__math a {
  color: var(--bbc-ink);
  border-bottom: 1px solid var(--bbc-rule-strong);
  transition: border-color var(--s9-d-fast) var(--s9-ease);
}
.s9-bbc__math a:hover { border-bottom-color: var(--bbc-accent); }

/* =========================================================================
   MOBILE — shared across every tool that uses the TE chassis.
   Below 640px the device tightens up, the LCD readout shrinks just enough
   to fit two currency numbers + an arrow, and rows that fight for width
   either wrap or stack.
   ========================================================================= */
@media (max-width: 640px) {
  .s9-bbc { padding-top: calc(var(--s9-header-h) + clamp(2rem, 5vw, 3.25rem)); }

  /* Chassis: tighter inner padding so the device doesn't push to the edges */
  .s9-bbc__device-inner { padding: 1rem; gap: 0; }
  .s9-bbc__panel { padding: .85rem .25rem; }
  .s9-bbc__device::after { inset: 8px; }

  /* Meta pills wrap instead of clipping when there are 3+ */
  .s9-bbc__meta-row { flex-wrap: wrap; gap: .55rem; row-gap: .5rem; }
  .s9-bbc__device-id--alt { order: 3; }

  /* Title: drop the 16-char clamp so long words don't overflow */
  .s9-bbc__title { max-width: none; font-size: clamp(2rem, 8vw, 2.75rem); }
  .s9-bbc__lead { font-size: 1.05rem; max-width: none; }

  /* Money row: keep on one line, but let the currency select shrink */
  .s9-bbc__row { flex-wrap: nowrap; }
  .s9-bbc__row input { font-size: 15px; padding: .65rem .7rem; min-width: 0; }
  .s9-bbc__row select { padding: 0 .55rem; font-size: 12px; }
  .s9-bbc__prefix, .s9-bbc__suffix { padding: 0 .7rem; font-size: 13px; }

  /* Slider row: keep slider full-width, LCD chip can wrap below */
  .s9-bbc__slider-wrap { grid-template-columns: 1fr; gap: .65rem; padding: .8rem .85rem; }
  .s9-bbc__slider-out { justify-self: end; }

  /* Choice cards: tighter padding */
  .s9-bbc__choice { padding: .6rem .75rem; gap: 0 .65rem; }
  .s9-bbc__choice-title { font-size: 13.5px; }
  .s9-bbc__choice-sub { font-size: 11px; }

  /* LCD readout: shrink the big number a touch so two amounts + arrow fit */
  .s9-bbc__lcd { padding: 1.1rem .85rem 1rem; }
  .s9-bbc__lcd-range { font-size: clamp(1.75rem, 8vw, 2.4rem); gap: .45rem; flex-wrap: wrap; }
  .s9-bbc__lcd-pct { font-size: 12px; flex-wrap: wrap; row-gap: .25rem; }
  .s9-bbc__lcd-current { gap: .45rem; font-size: 12px; flex-wrap: wrap; }
  .s9-bbc__lcd-current-amt { font-size: 16px; }

  /* Bar marker flag: keep it tightly clamped to the track so it never overflows */
  .s9-bbc__bar-flag { font-size: 10.5px; padding: 2px 6px; max-width: 90vw; }
  .s9-bbc__bar-axis { font-size: 10px; }

  /* Display header: stack label and sub-label so neither truncates */
  .s9-bbc__display-head { flex-direction: column; align-items: flex-start; gap: .35rem; }

  /* Verdict / Why / Save panels: tighten and keep mono readable */
  .s9-bbc__verdict { padding: .65rem .75rem; }
  .s9-bbc__verdict-msg { font-size: 13px; }
  .s9-bbc__save { padding: .8rem .85rem; }
  .s9-bbc__save-row { grid-template-columns: 1fr; gap: .5rem; }
  .s9-bbc__save-row button { padding: .55rem 1rem; }

  /* Actions: full-width stack so primary CTA isn't squeezed off-screen */
  .s9-bbc__actions { gap: .4rem; }
  .s9-bbc__action { flex: 1 1 auto; min-width: 0; padding: .55rem .65rem; font-size: 11.5px; }
  .s9-bbc__action--primary { flex-basis: 100%; }

  /* Device foot: wrap to two lines if it must, drop a redundant divider */
  .s9-bbc__device-foot { flex-wrap: wrap; row-gap: .35rem; font-size: 9.5px; margin: 0 .5rem; }

  /* Math disclosure: keep code/em readable on narrow screens */
  .s9-bbc__math p, .s9-bbc__math ul { font-size: 14px; }
}

/* Extra-narrow phones (≤ 380px): tighten further so the inner edges
   don't crush the device chassis padding. */
@media (max-width: 380px) {
  .s9-bbc__device-inner { padding: .75rem; }
  .s9-bbc__lcd-range { font-size: 1.6rem; }
  .s9-bbc__lcd { padding: .9rem .65rem .85rem; }
  .s9-bbc__choice-key { width: 24px; height: 24px; font-size: 11px; }
  .s9-bbc__device-foot { font-size: 9px; gap: .55rem; }
}