/* calculator.css — two-column input/result panel + result number + chart slot. */

.calculator-page__header {
  margin-bottom: var(--space-12);
}
.calculator-page__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--font-size-2xl);
  letter-spacing: -0.02em;
  margin-bottom: var(--space-3);
}
@media (min-width: 768px) {
  .calculator-page__title { font-size: var(--font-size-3xl); }
}
.calculator-page__lead {
  font-size: var(--font-size-lg);
  color: var(--color-ink-soft);
  max-width: var(--max-width-content);
  margin-bottom: var(--space-3);
}
.calculator-page__stand {
  font-family: var(--font-display);
  font-size: var(--font-size-sm);
  color: var(--color-ink-mute);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.calculator__panel {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-8);
  margin-block: var(--space-8) var(--space-12);
}
@media (min-width: 768px) {
  .calculator__panel { grid-template-columns: 1fr 1fr; }
}

.calculator__inputs,
.calculator__result {
  background: var(--color-white);
  border: 2px solid var(--color-ink);
  border-radius: 20px;
  padding: var(--space-8);
  box-shadow: var(--shadow-hard-md);
}

.calculator__section-label {
  font-family: var(--font-display);
  font-size: var(--font-size-xs);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-ink-mute);
  margin: 0 0 var(--space-4);
}

.calculator__result-label {
  font-family: var(--font-body);
  font-size: var(--font-size-sm);
  color: var(--color-ink-soft);
  margin: 0 0 var(--space-2);
}

.calculator__result-number {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 2.5rem;
  font-variant-numeric: tabular-nums;
  color: var(--color-coral);
  line-height: 1.1;
  display: inline-flex;
  align-items: baseline;
  justify-content: flex-end; /* short values (e.g. "0") hug the unit instead of leaving a 5ch gap */
  gap: 0.25rem;
  min-width: 6ch; /* CLS protection during digit-flip */
}
@media (min-width: 768px) {
  .calculator__result-number { font-size: 3.5rem; }
}

.calculator__result-unit {
  font-family: var(--font-display);
  font-weight: 500;
  font-size: var(--font-size-xl);
  color: var(--color-ink);
}

.calculator__result-context {
  font-size: var(--font-size-sm);
  color: var(--color-ink-soft);
  margin-top: var(--space-3);
}

.calculator__breakdown {
  list-style: none;
  padding: 0;
  margin: var(--space-6) 0 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  font-size: var(--font-size-sm);
}
.calculator__breakdown li {
  display: flex;
  justify-content: space-between;
  gap: var(--space-3);
  padding: var(--space-2) 0;
  border-top: 1px solid var(--color-border-soft);
}
.calculator__breakdown li:first-child { border-top: 0; }
.calculator__breakdown .label { color: var(--color-ink-soft); }
.calculator__breakdown .value {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 500;
}
.calculator__breakdown .value--positive { color: var(--color-success); }
.calculator__breakdown .value--negative { color: var(--color-error); }

.calculator__actions {
  display: flex;
  gap: var(--space-3);
  margin-top: var(--space-6);
  flex-wrap: wrap;
}

.calculator__chart {
  margin-top: var(--space-6);
  min-height: 200px;
}

/* Single-digit span used by digit-flip */
.digit {
  display: inline-block;
  perspective: 600px;
}
.digit__inner {
  display: inline-block;
  transform-style: preserve-3d;
  will-change: transform;
}

/* Inputs section helpers */
.calculator__inputs .field { margin-bottom: var(--space-4); }
.calculator__inputs .field:last-child { margin-bottom: 0; }

.slider-row {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: var(--space-4);
  align-items: center;
}
.slider-row .slider { margin-block: var(--space-2); }
.slider-row__value {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  min-width: 6ch;
  text-align: right;
  color: var(--color-ink);
}

/* FAQ block */
.faq-block { margin-block: var(--space-12); }
.faq-block h2 { margin-bottom: var(--space-6); }
.faq__item {
  background: var(--color-white);
  border: 2px solid var(--color-ink);
  border-radius: 12px;
  padding: var(--space-4) var(--space-6);
  margin-bottom: var(--space-3);
}
.faq__item > summary {
  cursor: pointer;
  list-style: none;
  font-family: var(--font-display);
  font-weight: 500;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-3);
}
.faq__item > summary::-webkit-details-marker { display: none; }
.faq__item > summary::after {
  content: "+";
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  flex-shrink: 0;
  border: 2px solid var(--color-ink);
  border-radius: 999px;
  font-weight: 600;
  transition: transform var(--motion-duration-fast) var(--motion-ease-standard);
}
.faq__item[open] > summary::after { content: "−"; transform: rotate(180deg); }
.faq__answer { padding-top: var(--space-3); color: var(--color-ink-soft); line-height: var(--line-height-loose); }

/* Sources block */
.sources-block { margin-block: var(--space-8); }
.sources-block summary {
  cursor: pointer;
  font-family: var(--font-display);
  font-weight: 500;
  font-size: var(--font-size-sm);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-ink-mute);
}
.sources-block ul { padding-left: var(--space-6); margin-top: var(--space-3); font-size: var(--font-size-sm); }

/* Related calcs */
.related-calcs { margin-block: var(--space-12); }
.related-calcs h2 { font-size: var(--font-size-xl); margin-bottom: var(--space-6); }