:root{
  --brand: #0ea5e9;
  --text: inherit;
  --card: color-mix(in oklab, var(--brand) 1%, transparent);
  --border: color-mix(in oklab, currentColor 22%, transparent);
}

* { box-sizing: border-box; }
html, body { height: 100%; }
html { font-size: 16px; }
body { margin: 0; font: 16px/1.55 system-ui, Segoe UI, Roboto, Arial, sans-serif; color: var(--text); }

.page { max-width: 1000px; margin: 0 auto; padding: 24px 16px; }
.container { display: grid; gap: 16px; }

.page-header { margin-bottom: 16px; }
.crumbs { opacity:.8; display:flex; gap:8px; align-items:center; font-size:.95rem; }
.lead { opacity:.9; margin: 6px 0 0; }
.centered { text-align: center; }
.highlight-seo {
  text-align: center;
  background: color-mix(in oklab, var(--brand) 15%, transparent);
  padding: 8px 12px;
  border-radius: 8px;
  font-weight: 500;
  margin-bottom: 10px;
}

.card { border: 1px solid var(--border); border-radius: 14px; padding: 14px; background: var(--card); }

/* Abas */
.tabs { display:flex; gap:8px; flex-wrap: wrap; }
.tab-btn { border:1px solid var(--border); background: transparent; padding:8px 10px; border-radius: 10px; cursor:pointer; }
.tab-btn.active { background: color-mix(in oklab, var(--brand) 14%, transparent); }
.tab-panel { display:none; }
.tab-panel.active { display:block; }

/* Form mobile-first */
form { display: grid; gap: 12px; }
.field { display: grid; gap: 6px; }
.field input, .field select {
  border: 1px solid var(--border);
  background: var(--card);
  border-radius: 10px;
  padding: 10px 12px;
  color: inherit;
  min-height: 44px;
  font-size: 16px;
}
.field.highlight select, .field.highlight input {
  border: 2px solid var(--brand);
  background: color-mix(in oklab, var(--brand) 8%, transparent);
}
.field.highlight label { color: var(--brand); font-weight: 600; }
.help { font-size: .9rem; opacity:.8; }
.error { color: #d92d20; min-height: 1.2em; font-size: .9rem; }

.config-grid { display: grid; gap: 12px; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }

/* Matriz simples */
.matrix {
  display: grid;
  gap: 10px;
  grid-template-columns: 140px 1fr 1fr;
  align-items: start;
}
.matrix .th { font-weight: 700; }
.matrix .cell { display: grid; gap: 6px; }
.unk-head { margin-bottom: 4px; font-size: .95rem; opacity:.9; }
.sr { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }

@media (max-width: 520px){
  .matrix { grid-template-columns: 110px 1fr; }
  .matrix > :nth-child(3), .matrix > :nth-child(6), .matrix > :nth-child(9) { grid-column: 1 / -1; }
}

/* Variáveis composta */
.vars { display: grid; gap: 10px; }
.var-row {
  display: grid;
  gap: 8px;
  grid-template-columns: 1fr 1fr 1fr 1fr;
  align-items: end;
  border: 1px dashed var(--border);
  border-radius: 12px;
  padding: 10px;
  background: color-mix(in oklab, var(--brand) 4%, transparent);
}
.var-row .field { margin: 0; }
.var-row .remove { justify-self: end; }
@media (max-width: 720px){
  .var-row { grid-template-columns: 1fr 1fr; }
}

/* Resultados */
.result-grid { display:grid; gap:12px; grid-template-columns: 1fr; margin: 6px 0 8px; }
@media (min-width: 680px){ .result-grid { grid-template-columns: repeat(3, minmax(0,1fr)); } }
.metric {
  text-align: center;
  padding: 10px 12px;
  border: 1px dashed var(--border);
  border-radius: 12px;
  background: color-mix(in oklab, var(--brand) 4%, transparent);
}
.metric-title { font-size: .95rem; opacity:.85; margin-bottom: 4px; }
.metric-value { font-size: clamp(22px, 5vw, 32px); font-weight: 800; }

.details { margin-top: 8px; }
.result-breakdown table { width: 100%; border-collapse: collapse; }
.result-breakdown td { padding: 6px 0; border-bottom: 1px dashed var(--border); }
.result-breakdown td:last-child { text-align: right; }
.result-actions { margin-top: 10px; display:flex; gap:8px; flex-wrap: wrap; justify-content: center; }

.doc h2 { margin-top: 4px; }
.doc h3 { margin: 12px 0 6px; }
.formula {
  margin: 6px 0 10px;
  padding: 10px 12px;
  border: 1px dashed var(--border);
  border-radius: 10px;
  background: color-mix(in oklab, var(--brand) 6%, transparent);
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

.page-footer { display:flex; gap:12px; align-items:center; flex-wrap: wrap; justify-content: center; margin-top: 8px; }

/* Back button */

.btn-back, a.btn-back {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: .85rem;
  font-weight: 600;
  text-decoration: none;
  padding: 8px 14px;
  border-radius: 12px;
  border: 1px solid #e2e8f0;
  background: #fff;
  color: #0f172a;
  cursor: pointer;
  transition: background .15s, border-color .15s, transform .12s;
  margin-bottom: 10px;
}
.btn-back:hover { transform: translateY(-1px); border-color: var(--calc-accent, #0ea5e9); background: color-mix(in srgb, var(--calc-accent, #0ea5e9) 5%, #fff); }
.btn-back svg { flex-shrink: 0; }
@media (prefers-color-scheme: dark){
  html:not([data-theme]) .btn-back { border-color: #1f2a37; background: #0f141b; color: #e6edf3; }
  html:not([data-theme]) .btn-back:hover { border-color: var(--calc-accent, #22c3f3); background: color-mix(in srgb, var(--calc-accent, #22c3f3) 5%, #0f141b); }
}
html[data-theme="dark"] .btn-back { border-color: #1f2a37 !important; background: #0f141b !important; color: #e6edf3 !important; }
html[data-theme="dark"] .btn-back:hover { border-color: var(--calc-accent, #22c3f3) !important; background: color-mix(in srgb, var(--calc-accent, #22c3f3) 5%, #0f141b) !important; }
html[data-theme="light"] .btn-back { border-color: #e2e8f0 !important; background: #fff !important; color: #0f172a !important; }
html[data-theme="light"] .btn-back:hover { border-color: var(--calc-accent, #0ea5e9) !important; background: color-mix(in srgb, var(--calc-accent, #0ea5e9) 5%, #fff) !important; }