/* ============================================================
   Engenharia Mecânica - Design System
   Tokens, layout, tipografia, componentes base
   ============================================================ */

:root {
  /* Paleta base (light) */
  --bg:            #f6f7f9;
  --bg-elev:       #ffffff;
  --bg-sunken:     #eceef2;
  --border:        #d8dce3;
  --border-strong: #b9c0cb;
  --text:          #16191f;
  --text-muted:    #5b6472;
  --text-faint:    #838d9c;

  /* Acentos */
  --accent:        #0b6bcb;
  --accent-hover:  #0a5aad;
  --accent-soft:   #e3eefb;
  --ok:            #1c7c46;
  --ok-soft:       #e0f2e8;
  --warn:          #a86500;
  --warn-soft:     #fbf0da;
  --err:           #bf2b2b;
  --err-soft:      #fbe6e6;
  --info:          #5b3fc4;
  --info-soft:     #ece7fb;

  /* Series de grafico (acessiveis em ambos os temas) */
  --s1: #0b6bcb; --s2: #d4713a; --s3: #1c7c46; --s4: #a03a8f;
  --s5: #8a7100; --s6: #2a8f9e; --s7: #b03030; --s8: #5b3fc4;

  --radius:    10px;
  --radius-sm: 6px;
  --radius-lg: 16px;
  --shadow:    0 1px 2px rgba(15,20,30,.06), 0 4px 14px rgba(15,20,30,.06);
  --shadow-lg: 0 8px 30px rgba(15,20,30,.12);

  --font: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, "SF Mono", "Cascadia Mono", Menlo, Consolas, monospace;

  --maxw: 1180px;
  --toc-w: 220px;
  --medida: 88ch;   /* comprimento maximo de linha de texto corrido */
  color-scheme: light;
}

/* O conteudo acompanha a largura do monitor, mas o texto corrido
   mantem uma medida legivel (ver regra .medida mais abaixo). */
@media (min-width: 1400px) { :root { --maxw: 1330px; --toc-w: 235px; } }
@media (min-width: 1650px) { :root { --maxw: 1540px; --toc-w: 250px; } }
@media (min-width: 1900px) { :root { --maxw: 1760px; --toc-w: 260px; } }
@media (min-width: 2300px) { :root { --maxw: 2040px; --toc-w: 280px; } }

:root[data-theme="dark"] {
  --bg:            #0e1116;
  --bg-elev:       #161b22;
  --bg-sunken:     #0a0d12;
  --border:        #262d38;
  --border-strong: #3a4453;
  --text:          #e8ecf2;
  --text-muted:    #9aa5b4;
  --text-faint:    #6d7887;

  --accent:        #4d9bf0;
  --accent-hover:  #6cadf5;
  --accent-soft:   #12243a;
  --ok:            #4ec27f;
  --ok-soft:       #10251a;
  --warn:          #e0a63a;
  --warn-soft:     #2a2010;
  --err:           #f06a6a;
  --err-soft:      #2c1414;
  --info:          #a38bf5;
  --info-soft:     #1d1830;

  --s1: #4d9bf0; --s2: #f0913f; --s3: #4ec27f; --s4: #e07ac9;
  --s5: #d8c447; --s6: #46c4d6; --s7: #f06a6a; --s8: #a38bf5;

  --shadow:    0 1px 2px rgba(0,0,0,.4), 0 4px 14px rgba(0,0,0,.3);
  --shadow-lg: 0 8px 30px rgba(0,0,0,.5);
  color-scheme: dark;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: 80px; }

body {
  margin: 0;
  font-family: var(--font);
  font-size: 15.5px;
  line-height: 1.65;
  background: var(--bg);
  color: var(--text);
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 { line-height: 1.25; font-weight: 650; letter-spacing: -0.015em; margin: 0 0 .5em; }
h1 { font-size: clamp(1.7rem, 3.4vw, 2.5rem); }
h2 { font-size: clamp(1.3rem, 2.4vw, 1.7rem); margin-top: 2.2em; }
h3 { font-size: 1.12rem; margin-top: 1.6em; }
h4 { font-size: 1rem; margin-top: 1.2em; color: var(--text-muted); }
p  { margin: 0 0 1em; }

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

code, kbd, samp { font-family: var(--mono); font-size: .9em; }
code {
  background: var(--bg-sunken);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: .1em .35em;
}
pre {
  background: var(--bg-sunken);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px 16px;
  overflow-x: auto;
  font-family: var(--mono);
  font-size: .86rem;
  line-height: 1.55;
}
pre code { background: none; border: 0; padding: 0; }

hr { border: 0; border-top: 1px solid var(--border); margin: 2.5em 0; }

/* ---------- Layout ---------- */
.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 20px; }
.wrap-narrow { max-width: 820px; margin: 0 auto; padding: 0 20px; }

.site-header {
  position: sticky; top: 0; z-index: 50;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
}
.site-header .bar {
  max-width: var(--maxw); margin: 0 auto; padding: 10px 20px;
  display: flex; align-items: center; gap: 14px;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 680; color: var(--text); letter-spacing: -.02em; }
.brand:hover { text-decoration: none; }
.brand .logo {
  width: 30px; height: 30px; border-radius: 8px; flex: none;
  display: grid; place-items: center;
  background: linear-gradient(135deg, var(--accent), var(--info));
  color: #fff; font-weight: 800; font-size: .8rem;
}
.brand small { display: block; font-weight: 450; font-size: .72rem; color: var(--text-faint); letter-spacing: .02em; }
.spacer { flex: 1; }

.nav-links { display: flex; gap: 4px; align-items: center; }
.nav-links a {
  padding: 6px 11px; border-radius: var(--radius-sm);
  color: var(--text-muted); font-size: .88rem; font-weight: 500;
}
.nav-links a:hover { background: var(--bg-sunken); color: var(--text); text-decoration: none; }

.icon-btn {
  width: 34px; height: 34px; flex: none;
  display: grid; place-items: center;
  border: 1px solid var(--border); border-radius: var(--radius-sm);
  background: var(--bg-elev); color: var(--text-muted);
  cursor: pointer; font-size: .95rem;
}
.icon-btn:hover { border-color: var(--border-strong); color: var(--text); }

.site-footer {
  margin-top: 72px; border-top: 1px solid var(--border);
  padding: 28px 20px 48px;
  color: var(--text-faint); font-size: .84rem;
}
.site-footer .wrap { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; }

/* ---------- Hero ---------- */
.hero { padding: 56px 0 32px; }
.hero .kicker {
  font-size: .76rem; font-weight: 650; letter-spacing: .12em; text-transform: uppercase;
  color: var(--accent); margin-bottom: 10px;
}
.hero p.lead { font-size: 1.07rem; color: var(--text-muted); max-width: 62ch; }

/* ---------- Cards / grid ---------- */
.grid { display: grid; gap: 14px; }
.grid.cols-2 { grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); }
.grid.cols-3 { grid-template-columns: repeat(auto-fill, minmax(255px, 1fr)); }
.grid.cols-4 { grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); }

.card {
  background: var(--bg-elev); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 16px 18px;
}
.card-link { display: block; color: inherit; transition: border-color .15s, transform .15s, box-shadow .15s; }
.card-link:hover {
  text-decoration: none; border-color: var(--accent);
  transform: translateY(-2px); box-shadow: var(--shadow);
}
.card-link h3 { margin: 6px 0 4px; font-size: 1.02rem; }
.card-link p { margin: 0; font-size: .855rem; color: var(--text-muted); line-height: 1.5; }
.card-top { display: flex; align-items: center; justify-content: space-between; gap: 8px; }

.tag {
  display: inline-flex; align-items: center; gap: 5px;
  font-size: .7rem; font-weight: 600; letter-spacing: .03em;
  padding: 2.5px 8px; border-radius: 999px;
  background: var(--bg-sunken); color: var(--text-muted); border: 1px solid var(--border);
}
.tag.accent { background: var(--accent-soft); color: var(--accent); border-color: transparent; }
.tag.ok     { background: var(--ok-soft);   color: var(--ok);   border-color: transparent; }
.tag.warn   { background: var(--warn-soft); color: var(--warn); border-color: transparent; }
.tag.err    { background: var(--err-soft);  color: var(--err);  border-color: transparent; }
.tag.info   { background: var(--info-soft); color: var(--info); border-color: transparent; }

.period-head {
  display: flex; align-items: baseline; gap: 12px;
  margin: 40px 0 14px; padding-bottom: 8px; border-bottom: 1px solid var(--border);
}
.period-head h2 { margin: 0; font-size: 1.15rem; }
.period-head span { font-size: .82rem; color: var(--text-faint); }

/* ---------- Botoes ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 7px;
  padding: 8px 16px; border-radius: var(--radius-sm);
  border: 1px solid var(--border); background: var(--bg-elev); color: var(--text);
  font: inherit; font-size: .9rem; font-weight: 550; cursor: pointer;
  transition: background .13s, border-color .13s, transform .06s;
}
.btn:hover { border-color: var(--border-strong); text-decoration: none; }
.btn:active { transform: translateY(1px); }
.btn:disabled { opacity: .45; cursor: not-allowed; }
.btn.primary { background: var(--accent); border-color: var(--accent); color: #fff; }
.btn.primary:hover { background: var(--accent-hover); }
.btn.ghost { background: transparent; }
.btn.sm { padding: 5px 11px; font-size: .82rem; }
.btn-row { display: flex; flex-wrap: wrap; gap: 9px; align-items: center; }

/* ---------- Conteudo teorico ---------- */
.section { margin-top: 44px; scroll-margin-top: 80px; }
.section > h2 { margin-top: 0; display: flex; align-items: center; gap: 10px; }

.topic {
  background: var(--bg-elev); border: 1px solid var(--border);
  border-radius: var(--radius); margin-bottom: 12px; overflow: hidden;
}
.topic > summary {
  cursor: pointer; padding: 13px 18px; font-weight: 600; font-size: 1rem;
  list-style: none; display: flex; align-items: center; gap: 10px;
}
.topic > summary::-webkit-details-marker { display: none; }
.topic > summary::before {
  content: "\25B8"; color: var(--text-faint); font-size: .9rem;
  transition: transform .15s; display: inline-block;
}
.topic[open] > summary::before { transform: rotate(90deg); }
.topic[open] > summary { border-bottom: 1px solid var(--border); }
.topic .topic-body { padding: 4px 18px 16px; }
.topic .topic-body > :first-child { margin-top: .6em; }

.formula {
  display: block; margin: 14px 0; padding: 12px 16px;
  background: var(--bg-sunken); border-left: 3px solid var(--accent);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  font-family: var(--mono); font-size: .92rem; overflow-x: auto;
}
.formula .where { display: block; margin-top: 7px; font-family: var(--font); font-size: .8rem; color: var(--text-muted); }

.callout {
  margin: 16px 0; padding: 12px 16px; border-radius: var(--radius);
  border: 1px solid var(--border); background: var(--bg-sunken); font-size: .92rem;
}
.callout strong:first-child { display: block; margin-bottom: 3px; }
.callout.tip  { background: var(--ok-soft);   border-color: transparent; }
.callout.warn { background: var(--warn-soft); border-color: transparent; }
.callout.note { background: var(--accent-soft); border-color: transparent; }

table.data {
  width: 100%; border-collapse: collapse; font-size: .88rem; margin: 14px 0;
}
table.data th, table.data td { padding: 8px 11px; border-bottom: 1px solid var(--border); text-align: left; }
table.data th { background: var(--bg-sunken); font-weight: 620; font-size: .82rem; letter-spacing: .01em; }
table.data td.num, table.data th.num { text-align: right; font-family: var(--mono); font-size: .86rem; }
table.data tbody tr:hover { background: var(--bg-sunken); }
.table-scroll { overflow-x: auto; -webkit-overflow-scrolling: touch; }

/* ---------- Indice lateral ---------- */
.page-layout { display: grid; grid-template-columns: 220px minmax(0, 1fr); gap: 40px; align-items: start; }
.toc { position: sticky; top: 78px; font-size: .86rem; }
.toc h4 { margin: 0 0 8px; font-size: .72rem; letter-spacing: .1em; text-transform: uppercase; color: var(--text-faint); }
.toc a { display: block; padding: 4.5px 10px; border-left: 2px solid var(--border); color: var(--text-muted); }
.toc a:hover, .toc a.active { color: var(--accent); border-left-color: var(--accent); background: var(--bg-elev); text-decoration: none; }

@media (max-width: 900px) {
  .page-layout { grid-template-columns: minmax(0, 1fr); gap: 0; }
  .toc { display: none; }
  .nav-links a { display: none; }
  .nav-links a.always { display: block; }
}

.skip-link { position: absolute; left: -9999px; }
.skip-link:focus { left: 12px; top: 12px; z-index: 99; background: var(--bg-elev); padding: 8px 14px; border-radius: 6px; border: 1px solid var(--accent); }

:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; border-radius: 3px; }

@media print {
  .site-header, .site-footer, .toc, .quiz-panel { display: none !important; }
}

/* Disciplina ainda nao construida */
.card-pendente { opacity: .52; }
.card-pendente h3 { font-size: 1.02rem; margin: 6px 0 4px; }
.card-pendente p { margin: 0; font-size: .855rem; color: var(--text-muted); line-height: 1.5; }

/* Medida legivel para texto corrido em monitores largos */
.topic-body > p, .section > p, .hero p.lead, .gabarito p, .explicacao p { max-width: var(--medida); }
/* só com o índice lateral visível: abaixo de 900 px a página tem uma coluna (regra acima) */
@media (min-width: 901px) {
  .page-layout { grid-template-columns: var(--toc-w) minmax(0, 1fr); }
}

/* ============================================================
   Fórmulas renderizadas (KaTeX)
   ============================================================ */
.katex { font-size: 1.06em; }
/* o MathML oculto do KaTeX é position:absolute; sem um ancestral posicionado ele escapava
   da rolagem das tabelas e alargava a página no celular */
.katex { position: relative; }
.tabela-wrap { overflow-x: auto; -webkit-overflow-scrolling: touch; }
@media (max-width: 420px) {
  .site-header .bar { gap: 8px; padding-left: 14px; padding-right: 14px; }
}
.tex-block { display: block; overflow-x: auto; overflow-y: hidden; padding: 2px 0; }
.tex-block .katex-display { margin: .35em 0; }
.tex-inline { white-space: nowrap; }
.tex-cru { font-family: var(--mono); font-size: .88em; color: var(--text-muted); }

/* a .formula agora hospeda o TeX; mantém a barra lateral e o "onde" */
.formula .tex-block { font-family: inherit; }
.formula:has(.tex-block) { font-family: var(--font); }

/* enquanto o KaTeX não chega, evita o salto de layout */
html:not(.katex-pronto) [data-tex]:empty,
html:not(.katex-pronto) [data-tex-inline]:empty { min-height: 1.2em; display: inline-block; }

/* ============================================================
   Exercícios resolvidos
   ============================================================ */
.exercicios { margin-top: 8px; }

.ex-res {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-elev);
  margin-bottom: 14px;
  overflow: hidden;
}
.ex-res > summary {
  cursor: pointer; list-style: none;
  padding: 14px 18px;
  display: grid; grid-template-columns: auto 1fr auto; gap: 12px; align-items: center;
}
.ex-res > summary::-webkit-details-marker { display: none; }
.ex-res > summary:hover { background: var(--bg-sunken); }
.ex-res[open] > summary { border-bottom: 1px solid var(--border); background: var(--bg-sunken); }
.ex-res .ex-num {
  width: 30px; height: 30px; border-radius: 8px; flex: none;
  display: grid; place-items: center;
  background: var(--accent-soft); color: var(--accent);
  font-weight: 700; font-size: .85rem;
}
.ex-res .ex-tit { font-weight: 620; font-size: .98rem; line-height: 1.35; }
.ex-res .ex-tit small {
  display: block; font-weight: 450; font-size: .8rem; color: var(--text-faint); margin-top: 2px;
}
.ex-res > summary::after {
  content: "\25B8"; color: var(--text-faint); transition: transform .15s;
}
.ex-res[open] > summary::after { transform: rotate(90deg); }

.ex-corpo { padding: 4px 20px 20px; }

.ex-enunciado {
  background: var(--bg-sunken);
  border-left: 3px solid var(--accent);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  padding: 14px 18px; margin: 16px 0 6px;
  font-size: .95rem; line-height: 1.65;
}
.ex-enunciado p:last-child { margin-bottom: 0; }
.ex-enunciado .rot {
  display: block; font-size: .7rem; font-weight: 700; letter-spacing: .1em;
  text-transform: uppercase; color: var(--accent); margin-bottom: 7px;
}
.ex-enunciado .dado {
  font-family: var(--mono); font-size: .9em;
  background: var(--bg-elev); border-radius: 4px; padding: .05em .35em;
  border: 1px solid var(--border);
}

.ex-dados {
  display: flex; flex-wrap: wrap; gap: 8px; margin: 14px 0;
}
.ex-dados .item {
  background: var(--bg-sunken); border: 1px solid var(--border);
  border-radius: var(--radius-sm); padding: 6px 11px; font-size: .84rem;
}
.ex-dados .item b { color: var(--text); font-weight: 620; }

.ex-passo {
  display: grid; grid-template-columns: 28px 1fr; gap: 13px;
  padding: 13px 0; border-bottom: 1px dashed var(--border);
}
.ex-passo:last-of-type { border-bottom: 0; }
.ex-passo .n {
  width: 26px; height: 26px; border-radius: 50%;
  display: grid; place-items: center;
  background: var(--accent-soft); color: var(--accent);
  font-size: .78rem; font-weight: 700;
}
.ex-passo .cab { font-weight: 620; font-size: .92rem; margin-bottom: 6px; }
.ex-passo .txt { font-size: .91rem; line-height: 1.6; color: var(--text-muted); margin-bottom: 7px; }
.ex-passo .txt:last-child { margin-bottom: 0; }
.ex-passo .conta {
  background: var(--bg-sunken); border-radius: var(--radius-sm);
  padding: 10px 14px; margin: 8px 0; overflow-x: auto;
}
.ex-passo .res {
  display: inline-block; margin-top: 6px;
  background: var(--accent-soft); color: var(--accent);
  border-radius: var(--radius-sm); padding: 6px 13px;
  font-family: var(--mono); font-size: .9rem; font-weight: 650;
}
.ex-passo .res.final { background: var(--ok-soft); color: var(--ok); }

.ex-resposta {
  margin-top: 18px; padding: 14px 18px;
  background: var(--ok-soft); border-radius: var(--radius);
  border-left: 3px solid var(--ok);
}
.ex-resposta .rot {
  display: block; font-size: .7rem; font-weight: 700; letter-spacing: .1em;
  text-transform: uppercase; color: var(--ok); margin-bottom: 6px;
}
.ex-resposta .valor { font-size: 1.02rem; font-weight: 600; }

.ex-nota {
  margin-top: 14px; padding: 11px 15px;
  background: var(--warn-soft); border-radius: var(--radius-sm);
  font-size: .87rem; line-height: 1.55;
}
.ex-nota b { display: block; margin-bottom: 3px; }

@media (max-width: 560px) {
  .ex-res > summary { grid-template-columns: auto 1fr; }
  .ex-corpo { padding-left: 14px; padding-right: 14px; }
  .ex-passo { grid-template-columns: 22px 1fr; gap: 9px; }
}

/* ============================================================
   Glossário — balão ao passar o mouse sobre uma variável
   ============================================================ */
.katex .glos {
  position: relative;
  cursor: help;
  border-bottom: 1px dotted var(--accent);
  padding-bottom: 1px;
}
.katex .glos:hover, .katex .glos:focus-visible {
  background: var(--accent-soft);
  border-radius: 3px;
  outline: none;
}

.glos-balao {
  position: fixed;
  z-index: 200;
  min-width: 190px;
  max-width: 320px;
  padding: 10px 13px;
  background: var(--bg-elev);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-lg);
  font-family: var(--font);
  font-style: normal;
  font-weight: 400;
  font-size: 12.5px;
  line-height: 1.5;
  text-align: left;
  white-space: normal;
  color: var(--text);
  opacity: 0;
  visibility: hidden;
  transform: translateY(4px);
  transition: opacity .12s, transform .12s;
  pointer-events: none;
}
.glos-balao.visivel { opacity: 1; visibility: visible; transform: translateY(0); }
.glos-balao::after {
  content: "";
  position: absolute;
  top: 100%; left: var(--seta, 50%);
  transform: translateX(-50%);
  border: 6px solid transparent;
  border-top-color: var(--border-strong);
}
.glos-balao.abaixo::after {
  top: auto; bottom: 100%;
  border-top-color: transparent;
  border-bottom-color: var(--border-strong);
}
.glos-balao b { display: block; font-weight: 650; margin-bottom: 3px; color: var(--text); }
.glos-balao .un {
  display: inline-block;
  font-family: var(--mono); font-size: 11.5px;
  color: var(--accent); background: var(--accent-soft);
  padding: 1px 6px; border-radius: 4px;
}
.glos-balao .obs {
  display: block; margin-top: 5px;
  font-size: 11.5px; color: var(--text-muted);
}

@media (max-width: 640px) {
  .glos-balao { min-width: 150px; max-width: 220px; }
}

/* ============================================================
   Busca na página
   ============================================================ */
.busca {
  display: flex;
  align-items: center;
  gap: 6px;
  margin: 0 0 18px;
  padding: 6px 8px;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: 10px;
  position: sticky;
  top: 8px;
  z-index: 40;
  box-shadow: 0 2px 10px rgba(0, 0, 0, .06);
}
.busca-lupa { font-size: 17px; color: var(--text-faint); padding: 0 2px; }
.busca-campo {
  flex: 1;
  min-width: 0;
  border: 0;
  background: transparent;
  color: var(--text);
  font: inherit;
  font-size: 14px;
  padding: 5px 2px;
  outline: none;
}
.busca-campo::placeholder { color: var(--text-faint); }
.busca-nav, .busca-fechar {
  border: 1px solid var(--border);
  background: transparent;
  color: var(--text-muted);
  border-radius: 7px;
  width: 26px;
  height: 26px;
  line-height: 1;
  font-size: 15px;
  cursor: pointer;
  flex: none;
}
.busca-nav:hover, .busca-fechar:hover { background: var(--bg-sunken); color: var(--text); }
.busca-conta {
  font-size: 12px;
  color: var(--text-faint);
  min-width: 74px;
  text-align: right;
  flex: none;
}
mark.busca-hit {
  background: rgba(250, 204, 21, .38);
  color: inherit;
  border-radius: 3px;
  padding: 0 1px;
}
mark.busca-hit-atual {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 0 0 2px var(--accent);
}
@media (max-width: 620px) {
  .busca-conta { min-width: 0; font-size: 11px; }
}

/* ---------- alternador "por período | por matéria" ---------- */
.alternador { display: inline-flex; border: 1px solid var(--border); border-radius: var(--radius-sm); overflow: hidden; background: var(--bg-elev); }
.alternador button {
  font: inherit; font-size: .85rem; font-weight: 550; padding: 7px 14px; border: 0; cursor: pointer;
  background: transparent; color: var(--text-muted); border-right: 1px solid var(--border);
}
.alternador button:last-child { border-right: 0; }
.alternador button:hover { color: var(--text); background: var(--bg-sunken); }
.alternador button.ativo { background: var(--accent); color: #fff; }
.nav-links a.nav-destaque { color: var(--accent); font-weight: 650; }

/* ---------- catálogo de simulações ---------- */
.card-sim { display: flex; flex-direction: column; }
.card-sim .card-top { flex-wrap: wrap; }
.card-sim .sim-tambem { font-size: .78rem; color: var(--text-faint); margin-top: 6px; }
.card-sim .sim-abrir { margin-top: auto; padding-top: 10px; font-size: .84rem; font-weight: 650; color: var(--accent); }
.barra-ferramentas { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; justify-content: space-between; margin-top: 8px; }
.barra-ferramentas input[type=search] {
  flex: 1 1 260px; max-width: 360px; padding: 9px 14px; border: 1px solid var(--border); border-radius: 8px;
  background: var(--bg-elev); color: var(--text); font: inherit; font-size: .9rem;
}

/* ---------- modo "só esta simulação" (?sim=) ---------- */
.modo-sim .hero, .modo-sim .toc, .modo-sim .busca,
.modo-sim .section:not(#simuladores), .modo-sim #simuladores > h2, .modo-sim #simuladores > p { display: none !important; }
.modo-sim .page-layout { grid-template-columns: minmax(0, 1fr); gap: 0; }
.modo-sim #simuladores { margin-top: 18px; }
.foco-barra {
  display: flex; flex-wrap: wrap; gap: 10px; align-items: center; margin: 0 0 16px;
  padding: 10px 12px; border: 1px solid var(--border); border-radius: var(--radius); background: var(--bg-elev);
}
.foco-barra .foco-disc { font-size: .88rem; color: var(--text-muted); }


/* ---------- novidades: estrela no canto dos cards da última atualização ---------- */
.card-novo { position: relative; border-color: color-mix(in srgb, #f5b301 55%, var(--border)); }
.estrela-novo {
  position: absolute; top: -11px; right: -11px; z-index: 2;
  width: 28px; height: 28px; border-radius: 50%;
  display: inline-flex; align-items: center; justify-content: center;
  font-size: 16px; line-height: 1; color: #fff;
  background: linear-gradient(145deg, #ffcf3f, #f29d00);
  box-shadow: 0 2px 8px rgba(242, 157, 0, .45), 0 0 0 2px var(--bg);
  animation: estrela-brilho 2.8s ease-in-out infinite;
  pointer-events: none;
}
@keyframes estrela-brilho {
  0%, 100% { transform: scale(1) rotate(0deg); }
  50% { transform: scale(1.12) rotate(12deg); }
}
@media (prefers-reduced-motion: reduce) { .estrela-novo { animation: none; } }
.legenda-novidades {
  margin: 12px 0 0; font-size: .92rem; color: var(--text-muted);
  display: flex; align-items: center; gap: 8px; flex-wrap: wrap;
}
.estrela-mini {
  display: inline-flex; align-items: center; justify-content: center;
  width: 22px; height: 22px; border-radius: 50%; font-size: 13px; color: #fff;
  background: linear-gradient(145deg, #ffcf3f, #f29d00);
}

/* ============================================================
   Formato livro (js/core/livro.js): sumário, capítulos, exemplos
   ============================================================ */
.livro-barra {
  position: fixed; left: 0; right: 0; top: 0; height: 3px; z-index: 60;
  background: transparent; opacity: 0; transition: opacity .2s; pointer-events: none;
}
.livro-barra.visivel { opacity: 1; }
.livro-barra span { display: block; height: 100%; width: 0; background: var(--accent); }

/* sumário */
.sumario-topo { display: flex; flex-wrap: wrap; gap: 12px 18px; align-items: center; justify-content: space-between; margin: 6px 0 14px; }
.sumario-prog { display: flex; align-items: center; gap: 10px; flex: 1 1 260px; }
.sumario-prog-barra { flex: 1; max-width: 260px; height: 8px; border-radius: 99px; background: var(--bg-sunken); border: 1px solid var(--border); overflow: hidden; }
.sumario-prog-barra span { display: block; height: 100%; width: 0; background: var(--ok); transition: width .3s; }
.sumario-prog-txt { font-size: .86rem; color: var(--text-muted); }
.sumario-parte {
  margin: 20px 0 6px; font-size: .74rem; font-weight: 700; letter-spacing: .09em;
  text-transform: uppercase; color: var(--text-faint);
}
.sumario-caps { list-style: none; margin: 0; padding: 0; display: grid; gap: 8px; }
.sumario-cap { border: 1px solid var(--border); border-radius: var(--radius); background: var(--bg-elev); padding: 10px 14px; }
.sumario-linha { display: flex; align-items: center; gap: 12px; }
.sumario-num {
  flex: none; width: 30px; height: 30px; border-radius: 50%; display: inline-flex; align-items: center; justify-content: center;
  font-weight: 700; font-size: .9rem; background: var(--accent-soft); color: var(--accent);
}
.sumario-titulo { font-weight: 600; color: var(--text); flex: 1; min-width: 0; }
.sumario-min { font-size: .78rem; color: var(--text-faint); white-space: nowrap; }
.sumario-ok { visibility: hidden; color: var(--ok); font-weight: 700; }
.sumario-cap.lido .sumario-ok { visibility: visible; }
.sumario-cap.lido .sumario-num { background: var(--ok-soft); color: var(--ok); }
.sumario-secoes { display: flex; flex-wrap: wrap; gap: 2px 14px; margin: 6px 0 0 42px; font-size: .82rem; }
.sumario-secoes a { color: var(--text-muted); }
.sumario-secoes a:hover { color: var(--accent); }

/* capítulo */
.capitulo { padding-top: 8px; border-top: 1px solid var(--border); }
.cap-kicker { margin: 18px 0 2px; font-size: .74rem; font-weight: 700; letter-spacing: .1em; text-transform: uppercase; color: var(--accent); }
.capitulo > h2 { font-size: 1.6rem; margin-bottom: 10px; }
.capitulo > h3 { margin-top: 34px; font-size: 1.18rem; scroll-margin-top: 80px; }
.capitulo > h3 .num, .capitulo .exemplo-cab .num { color: var(--accent); margin-right: 6px; }
.capitulo > p, .capitulo > ul, .capitulo > ol { max-width: var(--medida); line-height: 1.7; }
.cap-abertura {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 12px; margin: 14px 0 18px;
}
.cap-abertura > div { border: 1px solid var(--border); border-radius: var(--radius); padding: 12px 16px; background: var(--bg-elev); }
.cap-abertura h4 { margin: 0 0 6px; font-size: .78rem; letter-spacing: .07em; text-transform: uppercase; color: var(--text-faint); }
.cap-abertura ul { margin: 0; padding-left: 18px; font-size: .92rem; }
.cap-abertura li + li { margin-top: 3px; }
.cap-abertura p { margin: 0; font-size: .92rem; }

/* exemplo resolvido */
.exemplo { border: 1px solid var(--border); border-left: 4px solid var(--info); border-radius: var(--radius); background: var(--bg-elev); padding: 12px 18px; margin: 18px 0; }
.exemplo-cab { font-weight: 700; margin-bottom: 4px; }
.exemplo > p { margin: 6px 0; max-width: var(--medida); }
.exemplo details { margin-top: 8px; }
.exemplo summary { cursor: pointer; color: var(--info); font-weight: 600; font-size: .9rem; }
.exemplo ol.passos { margin: 10px 0 4px; padding-left: 22px; }
.exemplo ol.passos li { margin: 6px 0; }
.exemplo .resposta { margin-top: 8px; padding: 8px 12px; border-radius: var(--radius-sm); background: var(--info-soft); font-weight: 600; }

/* resumo e teste-se */
.cap-resumo { border-radius: var(--radius); background: var(--accent-soft); padding: 12px 18px; margin: 26px 0 14px; }
.cap-resumo h4, .teste-se h4 { margin: 0 0 6px; }
.cap-resumo ul { margin: 0; padding-left: 20px; }
.cap-resumo li { margin: 4px 0; }
.teste-se { margin: 14px 0; }
.teste-se details { border: 1px solid var(--border); border-radius: var(--radius-sm); padding: 8px 12px; margin: 6px 0; background: var(--bg-elev); }
.teste-se summary { cursor: pointer; font-weight: 500; }
.teste-se details p { margin: 8px 0 2px; color: var(--text-muted); }

/* rodapé de capítulo */
.cap-rodape { display: grid; grid-template-columns: 1fr auto 1fr; gap: 12px; align-items: center; margin: 24px 0 8px; }
.cap-nav {
  display: flex; flex-direction: column; gap: 2px; padding: 10px 14px; border: 1px solid var(--border);
  border-radius: var(--radius); background: var(--bg-elev); color: var(--text); font-weight: 600; font-size: .92rem;
}
.cap-nav small { font-weight: 500; font-size: .76rem; color: var(--text-faint); }
.cap-nav:hover { border-color: var(--accent); text-decoration: none; }
.cap-prox { text-align: right; }
.cap-meio { display: flex; flex-direction: column; gap: 6px; align-items: center; }
.cap-lido.ok { background: var(--ok-soft); border-color: var(--ok); color: var(--ok); }
.cap-lido-pulso { animation: cap-pulso .6s ease-out; }
@keyframes cap-pulso { 0% { transform: scale(1); } 40% { transform: scale(1.08); } 100% { transform: scale(1); } }
@media (prefers-reduced-motion: reduce) { .cap-lido-pulso { animation: none; } }
@media (max-width: 720px) {
  .cap-rodape { grid-template-columns: 1fr 1fr; }
  .cap-meio { grid-column: 1 / -1; grid-row: 1; flex-direction: row; justify-content: center; flex-wrap: wrap; }
  .sumario-secoes { margin-left: 0; }
  .sumario-min { display: none; }
}
@media (max-width: 520px) {
  .cap-rodape { grid-template-columns: 1fr; }
  .cap-prox { text-align: left; }
}
.livro-aviso-quiz { padding: 8px 12px; border-radius: var(--radius-sm); background: var(--accent-soft); font-size: .9rem; }
.lab-lista { display: grid; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); gap: 10px; padding: 0; list-style: none; }
.lab-lista a { display: block; height: 100%; padding: 10px 14px; border: 1px solid var(--border); border-radius: var(--radius); background: var(--bg-elev); color: var(--text); }
.lab-lista a:hover { border-color: var(--accent); text-decoration: none; }
.lab-lista small { display: block; color: var(--text-faint); font-size: .78rem; }
.modo-sim .lab-lista { display: none; }
@media print { .cap-rodape, .livro-barra, .sumario-topo { display: none !important; } .exemplo details, .teste-se details { display: block; } }

/* ---------- modo de leitura: completo × resumo ---------- */
html.modo-resumo .so-completo { display: none !important; }
.cap-aprofundar { display: none; margin: 4px 0 10px; }
html.modo-resumo .cap-aprofundar { display: block; }
/* no resumo, os pontos-chave sobem para logo abaixo do título do capítulo */
html.modo-resumo .capitulo { display: flex; flex-direction: column; }
html.modo-resumo .capitulo > .cap-kicker, html.modo-resumo .capitulo > h2 { order: -3; }
html.modo-resumo .capitulo > .cap-resumo { order: -2; margin-top: 4px; }
html.modo-resumo .capitulo > .cap-aprofundar { order: -1; }
html.modo-resumo .capitulo > h3 { margin-top: 20px; }
html.modo-resumo .capitulo .formula { margin: 8px 0; }

.modo-bloco { margin-top: 18px; }
.modo-pergunta { margin: 0 0 8px; font-size: .82rem; font-weight: 700; letter-spacing: .07em; text-transform: uppercase; color: var(--text-faint); }
.modo-leitura { display: inline-flex; border: 1px solid var(--border); border-radius: var(--radius); background: var(--bg-elev); padding: 3px; gap: 3px; }
.modo-leitura button {
  display: flex; flex-direction: column; align-items: flex-start; gap: 1px;
  border: 0; border-radius: calc(var(--radius) - 3px); background: transparent; color: var(--text-muted);
  padding: 8px 16px; cursor: pointer; font: inherit; text-align: left;
}
.modo-leitura button strong { font-size: .95rem; }
.modo-leitura button small { font-size: .76rem; color: var(--text-faint); }
.modo-leitura button:hover { color: var(--text); }
.modo-leitura button[aria-pressed="true"] { background: var(--accent); color: #fff; }
.modo-leitura button[aria-pressed="true"] small { color: rgba(255,255,255,.85); }
.modo-leitura button:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.modo-flutuante {
  position: fixed; right: 16px; bottom: 16px; z-index: 55; box-shadow: var(--shadow-lg);
  opacity: 0; transform: translateY(8px); pointer-events: none; transition: opacity .2s, transform .2s;
}
.modo-flutuante.visivel { opacity: 1; transform: none; pointer-events: auto; }
.modo-flutuante button { padding: 6px 12px; }
.modo-flutuante button small { display: none; }
.modo-sim .modo-flutuante, .modo-sim .modo-bloco { display: none !important; }
@media (prefers-reduced-motion: reduce) { .modo-flutuante { transition: none; } }
@media print { .modo-flutuante, .modo-bloco { display: none !important; } }

/* ---------- livro paginado: um capítulo por vez ---------- */
.pag-oculta { display: none !important; }
.livro-paginado:not(.pag-inicio) .hero { display: none; }
.livro-paginado .capitulo { border-top: 0; padding-top: 0; }
.livro-paginado .page-layout .section.pagina:first-child,
.livro-paginado .section.pagina { margin-top: 18px; }
html.modo-resumo .capitulo > .pag-topo { order: -4; }
.pag-topo {
  display: flex; align-items: center; gap: 10px; margin: 0 0 6px; padding: 6px;
  border: 1px solid var(--border); border-radius: var(--radius); background: var(--bg-elev);
}
.pag-onde { flex: 1; text-align: center; font-size: .86rem; color: var(--text-muted); }
.pag-onde a { color: var(--text-muted); font-weight: 600; }
.pag-onde a:hover { color: var(--accent); }
.pag-seta {
  flex: none; width: 38px; height: 34px; display: inline-flex; align-items: center; justify-content: center;
  border-radius: var(--radius-sm); font-size: 1.5rem; line-height: 1; color: var(--accent);
}
a.pag-seta:hover { background: var(--accent-soft); text-decoration: none; }
.cap-rodape { border-top: 1px solid var(--border); padding-top: 18px; margin-top: 30px; }

/* coluna da esquerda do livro */
.toc-livro { max-height: calc(100vh - 96px); overflow-y: auto; padding-right: 4px; }
.toc-livro .toc-parte { margin: 14px 0 4px; font-size: .68rem; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; color: var(--text-faint); }
.toc-livro a.toc-pag { display: flex; gap: 8px; align-items: baseline; border-left: 0; border-radius: var(--radius-sm); padding: 5px 8px; color: var(--text); }
.toc-livro a.toc-pag.active { background: var(--accent-soft); color: var(--accent); font-weight: 600; }
.toc-livro .toc-num {
  flex: none; width: 20px; height: 20px; border-radius: 50%; display: inline-flex; align-items: center; justify-content: center;
  font-size: .72rem; font-weight: 700; border: 1px solid var(--border-strong); color: var(--text-muted);
}
.toc-livro a.toc-pag.active .toc-num { border-color: var(--accent); color: var(--accent); }
.toc-livro a.toc-pag.lido .toc-num { background: var(--ok-soft); border-color: var(--ok); color: var(--ok); }
.toc-livro .toc-secoes { margin: 2px 0 6px 18px; border-left: 1px solid var(--border); }
.toc-livro .toc-secoes a { font-size: .8rem; padding: 3px 10px; border-left: 2px solid transparent; margin-left: -1px; }
.sumario-extras { display: flex; flex-wrap: wrap; gap: 8px; }
.sumario-extras a { padding: 8px 14px; border: 1px solid var(--border); border-radius: var(--radius); background: var(--bg-elev); color: var(--text); font-weight: 600; font-size: .9rem; }
.sumario-extras a small { display: block; font-weight: 500; font-size: .74rem; color: var(--text-faint); }
.sumario-extras a:hover { border-color: var(--accent); text-decoration: none; }

/* fórmula inline mais larga que a tela: rola dentro da linha em vez de alargar a página */
.capitulo > p, .capitulo li, .exemplo p, .cap-resumo li, .teste-se p,
.topic-body > p, .topic-body li, .callout { overflow-x: auto; overflow-y: hidden; }

/* ---------- figuras ilustrativas (js/core/figura.js) ---------- */
.fig {
  margin: 20px 0; padding: 10px 12px 8px;
  border: 1px solid var(--border); border-radius: var(--radius); background: var(--bg-elev);
}
.fig-tela { width: 100%; }
.fig canvas { display: block; margin: 0 auto; max-width: 100%; border-radius: var(--radius-sm); }
.fig-ctrl {
  display: flex; flex-wrap: wrap; gap: 6px 18px; align-items: center;
  margin: 8px 0 2px; padding-top: 8px; border-top: 1px solid var(--border);
}
.fig-campo { display: flex; flex-wrap: wrap; align-items: center; gap: 4px 8px; font-size: .82rem; color: var(--text-muted); flex: 1 1 260px; min-width: 0; }
.fig-campo .fig-rot { min-width: 0; }
.fig-campo input[type="range"] { flex: 1; min-width: 90px; accent-color: var(--accent); }
.fig-campo .fig-val { min-width: 62px; text-align: right; font-variant-numeric: tabular-nums; color: var(--text); font-weight: 600; }
.fig-play { flex: none; }
.fig figcaption { margin-top: 8px; font-size: .85rem; color: var(--text-muted); line-height: 1.5; }
.fig figcaption strong { color: var(--text); }
@media (max-width: 560px) {
  .fig { padding: 8px 10px 6px; }
  .fig-campo { flex: 1 1 100%; font-size: .78rem; }
}
@media print { .fig-ctrl { display: none; } }