/* ==========================================================================
   Tools section — hub + calculators
   Uses tokens from variables.css only. No hard-coded colours except shadows.
   ========================================================================== */

.tools-hero {
  padding: 72px 0 40px;
  border-bottom: 1px solid var(--color-border);
  background:
    radial-gradient(760px 420px at 82% 10%, var(--color-primary-soft), transparent 62%);
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
  font-size: 0.8rem;
  color: var(--color-text-muted);
  margin-bottom: 20px;
}

.breadcrumb a:hover { color: var(--color-primary); }
.breadcrumb span[aria-hidden] { opacity: 0.5; }

.tools-hero h1 {
  font-size: clamp(1.9rem, 4vw, 2.8rem);
  line-height: 1.1;
  letter-spacing: -0.02em;
  max-width: 20ch;
}

.tools-hero .lead {
  margin-top: 16px;
  max-width: 62ch;
  font-size: 1.05rem;
  color: var(--color-text-muted);
}

.tool-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 24px;
}

.pill {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 6px 13px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  font-size: 0.8rem;
  color: var(--color-text-muted);
}

.pill--accent {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: var(--color-primary-soft);
  font-weight: 600;
}

/* ---------- hub grid ---------- */

.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
  padding: 56px 0;
}

.tool-card {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 24px;
  border: 1px solid var(--color-border);
  border-top: 4px solid transparent;
  border-radius: var(--radius-md);
  background: var(--color-surface);
  box-shadow: var(--shadow-sm);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast), transform var(--transition-fast);
}

a.tool-card:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.tool-card__icon {
  width: 44px;
  height: 44px;
  display: grid;
  place-items: center;
  border-radius: 12px;
  background: var(--color-primary-soft);
  color: #fff;
  box-shadow: 0 6px 16px -4px var(--icon-shadow, rgba(0,0,0,0.25));
}

.tool-card__icon svg { width: 22px; height: 22px; stroke: #fff; }

/* bold, saturated color per card -- cycles through a 13-color palette */
.tools-grid .tool-card:nth-child(1)  { border-top-color: #16a34a; }
.tools-grid .tool-card:nth-child(1)  .tool-card__icon { --icon-shadow: rgba(22, 163, 74, 0.45); background: linear-gradient(135deg, #22c55e, #15803d); }
.tools-grid .tool-card:nth-child(1):hover  { border-color: #16a34a; }

.tools-grid .tool-card:nth-child(2)  { border-top-color: #2563eb; }
.tools-grid .tool-card:nth-child(2)  .tool-card__icon { --icon-shadow: rgba(37, 99, 235, 0.45); background: linear-gradient(135deg, #3b82f6, #1d4ed8); }
.tools-grid .tool-card:nth-child(2):hover  { border-color: #2563eb; }

.tools-grid .tool-card:nth-child(3)  { border-top-color: #9333ea; }
.tools-grid .tool-card:nth-child(3)  .tool-card__icon { --icon-shadow: rgba(147, 51, 234, 0.45); background: linear-gradient(135deg, #a855f7, #7e22ce); }
.tools-grid .tool-card:nth-child(3):hover  { border-color: #9333ea; }

.tools-grid .tool-card:nth-child(4)  { border-top-color: #ea580c; }
.tools-grid .tool-card:nth-child(4)  .tool-card__icon { --icon-shadow: rgba(234, 88, 12, 0.45); background: linear-gradient(135deg, #fb923c, #c2410c); }
.tools-grid .tool-card:nth-child(4):hover  { border-color: #ea580c; }

.tools-grid .tool-card:nth-child(5)  { border-top-color: #0891b2; }
.tools-grid .tool-card:nth-child(5)  .tool-card__icon { --icon-shadow: rgba(8, 145, 178, 0.45); background: linear-gradient(135deg, #22d3ee, #0e7490); }
.tools-grid .tool-card:nth-child(5):hover  { border-color: #0891b2; }

.tools-grid .tool-card:nth-child(6)  { border-top-color: #ca8a04; }
.tools-grid .tool-card:nth-child(6)  .tool-card__icon { --icon-shadow: rgba(202, 138, 4, 0.45); background: linear-gradient(135deg, #fbbf24, #b45309); }
.tools-grid .tool-card:nth-child(6):hover  { border-color: #ca8a04; }

.tools-grid .tool-card:nth-child(7)  { border-top-color: #db2777; }
.tools-grid .tool-card:nth-child(7)  .tool-card__icon { --icon-shadow: rgba(219, 39, 119, 0.45); background: linear-gradient(135deg, #f472b6, #be185d); }
.tools-grid .tool-card:nth-child(7):hover  { border-color: #db2777; }

.tools-grid .tool-card:nth-child(8)  { border-top-color: #4f46e5; }
.tools-grid .tool-card:nth-child(8)  .tool-card__icon { --icon-shadow: rgba(79, 70, 229, 0.45); background: linear-gradient(135deg, #818cf8, #4338ca); }
.tools-grid .tool-card:nth-child(8):hover  { border-color: #4f46e5; }

.tools-grid .tool-card:nth-child(9)  { border-top-color: #e11d48; }
.tools-grid .tool-card:nth-child(9)  .tool-card__icon { --icon-shadow: rgba(225, 29, 72, 0.45); background: linear-gradient(135deg, #fb7185, #be123c); }
.tools-grid .tool-card:nth-child(9):hover  { border-color: #e11d48; }

.tools-grid .tool-card:nth-child(10) { border-top-color: #0d9488; }
.tools-grid .tool-card:nth-child(10) .tool-card__icon { --icon-shadow: rgba(13, 148, 136, 0.45); background: linear-gradient(135deg, #2dd4bf, #0f766e); }
.tools-grid .tool-card:nth-child(10):hover { border-color: #0d9488; }

.tools-grid .tool-card:nth-child(11) { border-top-color: #65a30d; }
.tools-grid .tool-card:nth-child(11) .tool-card__icon { --icon-shadow: rgba(101, 163, 13, 0.45); background: linear-gradient(135deg, #a3e635, #4d7c0f); }
.tools-grid .tool-card:nth-child(11):hover { border-color: #65a30d; }

.tools-grid .tool-card:nth-child(12) { border-top-color: #0369a1; }
.tools-grid .tool-card:nth-child(12) .tool-card__icon { --icon-shadow: rgba(3, 105, 161, 0.45); background: linear-gradient(135deg, #38bdf8, #0369a1); }
.tools-grid .tool-card:nth-child(12):hover { border-color: #0369a1; }

.tools-grid .tool-card:nth-child(13) { border-top-color: #a21caf; }
.tools-grid .tool-card:nth-child(13) .tool-card__icon { --icon-shadow: rgba(162, 28, 175, 0.45); background: linear-gradient(135deg, #e879f9, #a21caf); }
.tools-grid .tool-card:nth-child(13):hover { border-color: #a21caf; }

.tool-card h3 { font-size: 1.05rem; letter-spacing: -0.01em; }
.tool-card p { font-size: 0.9rem; color: var(--color-text-muted); }

.tool-card__tag {
  margin-top: auto;
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-primary);
  font-weight: 600;
}

.tool-card--soon { opacity: 0.62; }
.tool-card--soon .tool-card__tag { color: var(--color-text-muted); }

/* ---------- calculator ---------- */

.calc {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr);
  gap: 24px;
  margin: 48px 0 8px;
  align-items: start;
}

@media (max-width: 900px) {
  .calc { grid-template-columns: 1fr; }
}

.calc__panel,
.calc__result {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-surface);
  box-shadow: var(--shadow-sm);
}

.calc__panel { padding: 24px; }

.calc__panel h2,
.calc__result h2 {
  font-size: 1rem;
  letter-spacing: -0.01em;
  margin-bottom: 4px;
}

.calc__hint {
  font-size: 0.82rem;
  color: var(--color-text-muted);
  margin-bottom: 20px;
}

.field-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.field-grid--full { grid-template-columns: 1fr; }

@media (max-width: 560px) {
  .field-grid { grid-template-columns: 1fr; }
}

.field { display: flex; flex-direction: column; gap: 6px; }
.field--span { grid-column: 1 / -1; }

.field label {
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--color-text);
  display: block;
}

.field label sub,
.field label sup { line-height: 0; }

.field label small {
  font-weight: 400;
  color: var(--color-text-muted);
  margin-left: 5px;
}

.field input[type="number"],
.field input[type="text"],
.field select {
  width: 100%;
  padding: 9px 11px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-bg);
  color: var(--color-text);
  font-family: inherit;
  font-size: 0.92rem;
  transition: border-color var(--transition-fast);
}

.field input:focus,
.field select:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-soft);
}

.input-unit { display: flex; gap: 8px; }
.input-unit input { flex: 1; }
.input-unit select { width: auto; flex-shrink: 0; }

.check-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 18px;
  margin-top: 4px;
}

.check {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  font-size: 0.84rem;
  color: var(--color-text);
  cursor: pointer;
}

.check input { accent-color: var(--color-primary); width: 15px; height: 15px; }

.calc__advanced {
  margin-top: 18px;
  border-top: 1px solid var(--color-border);
  padding-top: 14px;
}

.calc__advanced summary {
  cursor: pointer;
  font-size: 0.84rem;
  font-weight: 600;
  color: var(--color-primary);
  list-style: none;
}

.calc__advanced summary::-webkit-details-marker { display: none; }
.calc__advanced summary::before { content: "+ "; }
.calc__advanced[open] summary::before { content: "– "; }
.calc__advanced .field-grid { margin-top: 14px; }

/* ---------- result ---------- */

.calc__result { position: sticky; top: calc(var(--header-height) + 16px); overflow: hidden; }
@media (max-width: 900px) { .calc__result { position: static; } }

.verdict {
  padding: 22px 24px;
  border-bottom: 1px solid var(--color-border);
}

.verdict__badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 15px;
  border-radius: var(--radius-pill);
  font-weight: 700;
  font-size: 0.86rem;
  letter-spacing: 0.02em;
}

.verdict__badge svg { width: 16px; height: 16px; }

.is-pass  { background: var(--color-primary-soft); color: var(--color-primary); }
.is-fail  { background: rgba(198, 60, 48, 0.12); color: #c63c30; }
.is-idle  { background: var(--color-bg-alt); color: var(--color-text-muted); }
.is-scope { background: rgba(214, 148, 32, 0.14); color: #a06d0d; }

:root[data-theme="dark"] .is-fail  { background: rgba(232, 106, 94, 0.16); color: #e86a5e; }
:root[data-theme="dark"] .is-scope { background: rgba(230, 175, 70, 0.16); color: #e6af46; }

.verdict__headline {
  margin-top: 14px;
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.verdict__sub {
  margin-top: 6px;
  font-size: 0.87rem;
  color: var(--color-text-muted);
}

.readout { padding: 6px 24px 20px; }

.readout__row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 16px;
  padding: 11px 0;
  border-bottom: 1px solid var(--color-border);
  font-size: 0.88rem;
}

.readout__row:last-child { border-bottom: 0; }
.readout__row dt { color: var(--color-text-muted); }
.readout__row dd { margin: 0; font-weight: 600; font-variant-numeric: tabular-nums; }
.readout__row dd small { font-weight: 400; color: var(--color-text-muted); margin-left: 3px; }

.readout__was {
  display: block;
  font-size: 0.76rem;
  font-weight: 400;
  color: var(--color-text-muted);
  opacity: 0.7;
  margin-top: 2px;
}

.result-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  padding: 0 24px 24px;
}

.result-actions .btn { font-size: 0.82rem; padding: 8px 16px; }

.copied-note {
  font-size: 0.78rem;
  color: var(--color-primary);
  padding: 0 24px 18px;
  display: none;
}

.copied-note.is-visible { display: block; }

/* ---------- prose / explainer ---------- */

.tool-prose {
  padding: 8px 0 64px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 280px;
  gap: 48px;
  align-items: start;
}

@media (max-width: 900px) {
  .tool-prose { grid-template-columns: 1fr; gap: 32px; }
}

.tool-prose__main > * + * { margin-top: 18px; }
.tool-prose h2 { font-size: 1.45rem; letter-spacing: -0.02em; margin-top: 44px; }
.tool-prose h3 { font-size: 1.05rem; margin-top: 28px; }
.tool-prose p,
.tool-prose li { color: var(--color-text-muted); font-size: 0.96rem; }
.tool-prose strong { color: var(--color-text); }
.tool-prose ul { display: grid; gap: 8px; padding-left: 20px; list-style: disc; }
.tool-prose a:not(.btn) { color: var(--color-primary); text-decoration: underline; text-underline-offset: 2px; }

.formula {
  display: block;
  padding: 16px 18px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border);
  background: var(--color-bg-alt);
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.86rem;
  color: var(--color-text);
  overflow-x: auto;
  white-space: pre;
  line-height: 1.7;
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.87rem;
}

.data-table th,
.data-table td {
  text-align: left;
  padding: 10px 12px;
  border-bottom: 1px solid var(--color-border);
}

.data-table th {
  font-weight: 600;
  color: var(--color-text);
  background: var(--color-bg-alt);
}

.data-table td { color: var(--color-text-muted); }
.data-table td strong { color: var(--color-text); }
.table-wrap { overflow-x: auto; }

.callout {
  border-left: 3px solid var(--color-primary);
  background: var(--color-primary-soft);
  padding: 16px 18px;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.callout p { color: var(--color-text); font-size: 0.92rem; }

.faq-item {
  border-bottom: 1px solid var(--color-border);
  padding: 16px 0;
}

.faq-item h3 { margin: 0 0 8px; font-size: 1rem; }

/* sidebar */

.tool-aside {
  position: sticky;
  top: calc(var(--header-height) + 16px);
  display: grid;
  gap: 16px;
}

@media (max-width: 900px) { .tool-aside { position: static; } }

.aside-card {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-surface);
  padding: 20px;
}

.aside-card h3 { font-size: 0.95rem; margin-bottom: 10px; }
.aside-card p { font-size: 0.86rem; color: var(--color-text-muted); margin-bottom: 14px; }
.aside-card ul { display: grid; gap: 9px; font-size: 0.86rem; }
.aside-card ul a { color: var(--color-text-muted); }
.aside-card ul a:hover { color: var(--color-primary); }

.aside-card--cta { border-color: var(--color-primary); background: var(--color-primary-soft); }
.aside-card--cta p { color: var(--color-text); }

.source-list { font-size: 0.8rem; }
.source-list a { color: var(--color-text-muted); text-decoration: underline; text-underline-offset: 2px; }
.source-list a:hover { color: var(--color-primary); }

.disclaimer {
  margin-top: 40px;
  padding: 16px 18px;
  border: 1px dashed var(--color-border);
  border-radius: var(--radius-sm);
  font-size: 0.82rem;
  color: var(--color-text-muted);
}

/* the .field display:flex rule outranks the UA [hidden] rule */
[hidden] { display: none !important; }

/* --- octave-band bar charts ------------------------------------------------ */

.charts-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
  margin-top: 24px;
}

.chart-panel {
  padding: 20px 24px;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  background: var(--color-surface);
}

.chart-panel h3 {
  font-size: 0.92rem;
  margin-bottom: 14px;
}

.chart-panel h3 small {
  font-weight: 400;
  color: var(--color-text-muted);
}

.chart-row-label {
  font-size: 0.76rem;
  font-weight: 600;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin: 14px 0 6px;
}

.chart-row-label:first-of-type { margin-top: 0; }

.chart-bars {
  display: flex;
  align-items: flex-end;
  gap: 6px;
}

.chart-bar-col {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.chart-bar-track {
  display: flex;
  align-items: flex-end;
  width: 100%;
  height: 120px;
}

.chart-bar {
  width: 100%;
  flex-shrink: 0;
  border-radius: 3px 3px 0 0;
  background: var(--color-border);
  transition: height 0.15s ease;
}

.chart-bar--sum {
  background: var(--color-primary);
}

.chart-bar-label {
  font-size: 0.68rem;
  font-weight: 600;
  color: var(--color-text-muted);
  margin-top: 4px;
}

.chart-bar-freq {
  font-size: 0.62rem;
  color: var(--color-text-muted);
  opacity: 0.7;
}

.chart-unit {
  text-align: right;
  font-size: 0.68rem;
  color: var(--color-text-muted);
  margin-top: 2px;
}

/* --- unit converter ---------------------------------------------------- */

#units-converter {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 20px;
}

.unit-card {
  padding: 20px;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  background: var(--color-surface);
}

.unit-card h3 {
  font-size: 0.92rem;
  margin-bottom: 14px;
}

.unit-input-row {
  display: flex;
  gap: 8px;
  margin-bottom: 14px;
}

.unit-value {
  flex: 1;
  min-width: 0;
  padding: 9px 10px;
  border-radius: 8px;
  border: 1.5px solid var(--color-border);
  background: var(--color-bg-alt);
  color: var(--color-text);
  font-size: 0.92rem;
  font-family: inherit;
}

.unit-select {
  flex-shrink: 0;
  width: auto;
  padding: 9px 10px;
  border-radius: 8px;
  border: 1.5px solid var(--color-border);
  background: var(--color-bg-alt);
  color: var(--color-text);
  font-size: 0.88rem;
  font-family: inherit;
}

.unit-value:focus,
.unit-select:focus {
  outline: none;
  border-color: var(--color-primary);
}

.unit-results {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.unit-result {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  padding: 7px 2px;
  border-bottom: 1px solid var(--color-border);
  font-size: 0.86rem;
}

.unit-result:last-child { border-bottom: none; }

.unit-result span { color: var(--color-text-muted); }
.unit-result strong { color: var(--color-text); font-variant-numeric: tabular-nums; }