/* ====================================================================
   Estação TT514 — leitor de estudos (tema osciloscópio)
   ==================================================================== */
@font-face{font-family:"Sora";src:url("../fonts/sora-600.woff2") format("woff2");font-weight:600;font-display:swap}
@font-face{font-family:"Sora";src:url("../fonts/sora-700.woff2") format("woff2");font-weight:700;font-display:swap}
@font-face{font-family:"Atkinson";src:url("../fonts/atkinson-400.woff2") format("woff2");font-weight:400;font-display:swap}
@font-face{font-family:"Atkinson";src:url("../fonts/atkinson-700.woff2") format("woff2");font-weight:700;font-display:swap}
@font-face{font-family:"PlexMono";src:url("../fonts/ibmplexmono-400.woff2") format("woff2");font-weight:400;font-display:swap}
@font-face{font-family:"PlexMono";src:url("../fonts/ibmplexmono-600.woff2") format("woff2");font-weight:600;font-display:swap}

:root{
  --bg:#0a0e16; --bg2:#0d1320; --panel:#0f1626; --panel2:#131c2e;
  --ink:#e7eefb; --ink-soft:#aebbd4; --ink-dim:#7488a8;
  --line:#1e2a40; --line2:#27374f;
  --blue:#3fa9f5; --cyan:#4fe3c1; --violet:#9b8cff; --amber:#e8b84b;
  --red:#e5645a; --green:#52d39a; --slate:#8aa0bf;
  --shadow:0 10px 40px rgba(0,0,0,.45);
  --display:"Sora",system-ui,sans-serif;
  --body:"Atkinson","Segoe UI",system-ui,sans-serif;
  --mono:"PlexMono",ui-monospace,Consolas,monospace;
  --sidebar-w:312px; --read-w:820px;
}
html[data-theme="light"]{
  --bg:#eef2f8; --bg2:#e7edf6; --panel:#ffffff; --panel2:#f3f6fb;
  --ink:#16202f; --ink-soft:#3c4a60; --ink-dim:#6b7c95;
  --line:#d8e0ec; --line2:#c4d0e0;
  --blue:#1f6fc4; --cyan:#0f9b86; --violet:#6b54d6; --amber:#b07d12;
  --red:#c0392b; --green:#1f8a5b; --slate:#5a6c86;
  --shadow:0 10px 32px rgba(40,60,100,.16);
}

*{box-sizing:border-box}
html,body{margin:0;padding:0}
body{
  background:var(--bg); color:var(--ink); font-family:var(--body);
  font-size:18px; line-height:1.72; -webkit-font-smoothing:antialiased;
  background-image:
    radial-gradient(1200px 600px at 78% -8%, rgba(63,169,245,.07), transparent 60%),
    radial-gradient(900px 500px at 8% 102%, rgba(79,227,193,.06), transparent 60%),
    linear-gradient(transparent 0 calc(100% - 1px), rgba(127,160,200,.04) 100%),
    linear-gradient(90deg, transparent 0 calc(100% - 1px), rgba(127,160,200,.04) 100%);
  background-size:auto,auto,28px 28px,28px 28px;
}

/* ----------------------------- SIDEBAR ----------------------------- */
#sidebar{
  position:fixed; top:0; left:0; width:var(--sidebar-w); height:100vh;
  background:linear-gradient(180deg,var(--panel),var(--bg2));
  border-right:1px solid var(--line); display:flex; flex-direction:column;
  z-index:40;
}
.brand{display:flex; align-items:center; gap:12px; padding:18px 20px 14px; border-bottom:1px solid var(--line)}
.brand .scope{width:34px;height:34px;border-radius:9px;flex:0 0 auto;
  background:radial-gradient(circle at 50% 40%, rgba(79,227,193,.25), rgba(63,169,245,.12));
  border:1px solid var(--line2); display:grid; place-items:center; position:relative; overflow:hidden}
.brand .scope i{width:20px;height:2px;border-radius:2px;background:var(--cyan);
  box-shadow:0 0 8px var(--cyan); position:relative}
.brand .scope i::before,.brand .scope i::after{content:"";position:absolute;top:0;height:2px;border-radius:2px;background:var(--cyan);opacity:.5}
.brand .scope i::before{left:-9px;width:6px;transform:translateY(-4px)}
.brand .scope i::after{right:-9px;width:6px;transform:translateY(4px)}
.brand-txt{font-family:var(--display);font-weight:700;font-size:17px;line-height:1.1;display:flex;flex-direction:column}
.brand-txt b{color:var(--cyan);font-weight:700}
.brand-txt small{font-family:var(--mono);font-weight:400;font-size:10.5px;letter-spacing:.04em;color:var(--ink-dim);margin-top:3px;text-transform:uppercase}

.prova-switch{display:flex;gap:8px;padding:12px 16px 4px}
.prova-btn{flex:1;display:flex;flex-direction:column;align-items:flex-start;gap:1px;cursor:pointer;
  padding:8px 11px;border-radius:10px;background:var(--panel2);border:1px solid var(--line2);
  color:var(--ink-soft);transition:.15s;text-align:left}
.prova-btn b{font-family:var(--display);font-size:14px;font-weight:700}
.prova-btn span{font-family:var(--mono);font-size:9.5px;letter-spacing:.02em;color:var(--ink-dim);text-transform:uppercase}
.prova-btn:hover{border-color:var(--cyan);color:var(--ink)}
.prova-btn.active{background:linear-gradient(120deg,rgba(63,169,245,.20),rgba(79,227,193,.12));border-color:var(--cyan);color:var(--ink)}
.prova-btn.active b{color:var(--cyan)}

.prog-geral{padding:13px 20px;border-bottom:1px solid var(--line)}
.pg-row{display:flex;justify-content:space-between;font-family:var(--mono);font-size:11px;color:var(--ink-dim);text-transform:uppercase;letter-spacing:.05em;margin-bottom:7px}
.pg-row span:last-child{color:var(--cyan);font-weight:600}
.bar{height:7px;border-radius:6px;background:var(--panel2);overflow:hidden;border:1px solid var(--line)}
.bar i{display:block;height:100%;width:0;border-radius:6px;background:linear-gradient(90deg,var(--blue),var(--cyan));transition:width .35s ease}

#toc{flex:1;overflow-y:auto;padding:10px 10px 20px}
.toc-grupo{margin-top:8px}
.toc-h{font-family:var(--mono);font-size:11px;letter-spacing:.06em;text-transform:uppercase;color:var(--ink-dim);padding:10px 12px 6px}
.toc-link{display:flex;align-items:center;gap:10px;padding:8px 11px;border-radius:9px;color:var(--ink-soft);text-decoration:none;cursor:pointer;border:1px solid transparent;transition:background .15s,border-color .15s,color .15s}
.toc-link:hover{background:var(--panel2);color:var(--ink)}
.toc-link.active{background:linear-gradient(90deg,rgba(63,169,245,.16),rgba(79,227,193,.08));border-color:var(--line2);color:var(--ink)}
.toc-link.active .toc-num{background:var(--blue);color:#04121f;border-color:transparent}
.toc-num{flex:0 0 auto;width:24px;height:24px;border-radius:7px;display:grid;place-items:center;font-family:var(--mono);font-size:12px;font-weight:600;background:var(--panel2);border:1px solid var(--line2);color:var(--ink-soft)}
.toc-name{flex:1;font-size:14.5px;line-height:1.25}
.toc-pill{flex:0 0 auto;font-family:var(--mono);font-size:10px;color:var(--ink-dim);min-width:30px;text-align:right}
.toc-pill.full{color:var(--green);font-weight:600}

.side-foot{display:flex;gap:8px;padding:12px 16px;border-top:1px solid var(--line)}
.ghost{flex:1;font-family:var(--mono);font-size:11.5px;letter-spacing:.03em;color:var(--ink-soft);background:var(--panel2);border:1px solid var(--line2);border-radius:8px;padding:9px 6px;cursor:pointer;transition:.15s}
.ghost:hover{color:var(--ink);border-color:var(--cyan)}

/* ----------------------------- READER ----------------------------- */
#reader{margin-left:var(--sidebar-w);min-height:100vh;display:flex;flex-direction:column}
#topbar{position:sticky;top:0;z-index:30;display:flex;align-items:center;gap:12px;
  padding:12px 26px;background:color-mix(in oklab,var(--bg) 86%, transparent);
  backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.icon-btn{display:none;background:var(--panel2);border:1px solid var(--line2);color:var(--ink);border-radius:8px;width:40px;height:40px;font-size:18px;cursor:pointer}
.search-wrap{position:relative;flex:1;max-width:560px;margin:0 auto}
#busca{width:100%;font-family:var(--body);font-size:15px;color:var(--ink);background:var(--panel);
  border:1px solid var(--line2);border-radius:11px;padding:11px 16px;outline:none;transition:.18s}
#busca:focus{border-color:var(--cyan);box-shadow:0 0 0 3px rgba(79,227,193,.15)}
#busca::placeholder{color:var(--ink-dim)}
#resultsBusca{position:absolute;top:calc(100% + 8px);left:0;right:0;background:var(--panel);border:1px solid var(--line2);border-radius:12px;box-shadow:var(--shadow);overflow:hidden;max-height:60vh;overflow-y:auto;z-index:50}
#resultsBusca a{display:block;padding:11px 15px;text-decoration:none;color:var(--ink);border-bottom:1px solid var(--line)}
#resultsBusca a:last-child{border-bottom:none}
#resultsBusca a:hover{background:var(--panel2)}
#resultsBusca a b{display:block;font-size:14px;font-family:var(--display);font-weight:600}
#resultsBusca a span{display:block;font-size:12px;color:var(--ink-dim);font-family:var(--mono);margin-top:2px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
#resultsBusca .no-hit{padding:14px 15px;color:var(--ink-dim);font-size:13px}
.home-link{flex:0 0 auto;width:40px;height:40px;display:grid;place-items:center;border-radius:8px;text-decoration:none;color:var(--ink-soft);background:var(--panel2);border:1px solid var(--line2);font-size:19px}
.home-link:hover{color:var(--cyan);border-color:var(--cyan)}

#conteudo{width:100%;max-width:var(--read-w);margin:0 auto;padding:30px 26px 40px;flex:1}
.loading{color:var(--ink-dim);text-align:center;margin-top:80px;font-family:var(--mono)}

/* headings & text */
.cap-title{font-family:var(--display);font-weight:700;font-size:33px;line-height:1.15;margin:6px 0 26px;letter-spacing:-.01em}
.cap-title .cap-num{display:inline-block;font-family:var(--mono);font-size:14px;font-weight:600;color:#04121f;background:linear-gradient(135deg,var(--blue),var(--cyan));padding:4px 11px;border-radius:8px;vertical-align:middle;margin-right:12px}
h2.secao,h3.secao{font-family:var(--display);line-height:1.25;scroll-margin-top:80px;display:flex;align-items:flex-start;gap:10px}
h2.secao{font-size:24px;font-weight:700;margin:38px 0 14px;padding-bottom:9px;border-bottom:1px solid var(--line)}
h3.secao{font-size:19.5px;font-weight:600;margin:28px 0 10px;color:var(--ink)}
h2.secao::after{content:"";position:absolute}
.bloco-p{margin:0 0 15px}
#conteudo strong{color:var(--ink);font-weight:700}
#conteudo strong.alert{color:var(--red)}
#conteudo em{color:var(--ink-soft);font-style:italic}
#conteudo code{font-family:var(--mono);font-size:.9em;background:var(--panel2);border:1px solid var(--line);border-radius:5px;padding:1px 5px;color:var(--cyan)}
.bloco-lista{margin:0 0 16px;padding-left:24px}
.bloco-lista li{margin:6px 0}
.bloco-lista ul,.bloco-lista ol{margin:8px 0;padding-left:22px}

/* equations */
.equacao{margin:16px 0;padding:6px 4px;overflow-x:auto;overflow-y:hidden;text-align:center}
.equacao::-webkit-scrollbar{height:7px}
.equacao::-webkit-scrollbar-thumb{background:var(--line2);border-radius:6px}
.equacao.destaque{background:linear-gradient(120deg,rgba(63,169,245,.10),rgba(79,227,193,.07));
  border:1px solid var(--line2);border-left:3px solid var(--cyan);border-radius:12px;padding:14px 12px;box-shadow:inset 0 0 24px rgba(79,227,193,.05)}
.katex{font-size:1.06em}
.katex-display{margin:0}
.ktx-fail{color:var(--red);font-family:var(--mono);font-size:.85em}

/* ----------------------------- CAIXAS ----------------------------- */
.caixa{position:relative;margin:18px 0;border-radius:13px;border:1px solid var(--line2);
  background:var(--panel);border-left-width:4px;padding:0;overflow:hidden;box-shadow:0 2px 14px rgba(0,0,0,.12)}
.caixa-title{font-family:var(--display);font-weight:700;font-size:15px;padding:11px 16px 9px;display:flex;align-items:center;gap:9px;letter-spacing:.01em}
.caixa-title::before{font-size:16px;line-height:1}
.caixa-body{padding:2px 16px 13px}
.caixa-body>*:first-child{margin-top:6px}
.caixa-body .bloco-p:last-child{margin-bottom:4px}
.caixa-body .equacao{margin:10px 0}

.caixa.intuicao{border-left-color:var(--slate);background:color-mix(in oklab,var(--slate) 7%,var(--panel))}
.caixa.intuicao .caixa-title{color:var(--slate)} .caixa.intuicao .caixa-title::before{content:"💡"}
.caixa.formula{border-left-color:var(--amber);background:color-mix(in oklab,var(--amber) 8%,var(--panel))}
.caixa.formula .caixa-title{color:var(--amber)} .caixa.formula .caixa-title::before{content:"📐"}
.caixa.receita{border-left-color:var(--green);background:color-mix(in oklab,var(--green) 8%,var(--panel))}
.caixa.receita .caixa-title{color:var(--green)} .caixa.receita .caixa-title::before{content:"✅"}
.caixa.alerta{border-left-color:var(--red);background:color-mix(in oklab,var(--red) 9%,var(--panel))}
.caixa.alerta .caixa-title{color:var(--red)} .caixa.alerta .caixa-title::before{content:"⚠️"}
.caixa.exemplo{border-left-color:var(--blue);background:color-mix(in oklab,var(--blue) 8%,var(--panel))}
.caixa.exemplo .caixa-title{color:var(--blue)} .caixa.exemplo .caixa-title::before{content:"🧭"}
.caixa.resposta{border-left-color:var(--cyan);background:color-mix(in oklab,var(--cyan) 9%,var(--panel))}
.caixa.resposta .caixa-title{color:var(--cyan)} .caixa.resposta .caixa-title::before{content:"🎯"}

/* ----------------------------- EXERCÍCIOS ----------------------------- */
.exercicio{margin:22px 0;border:1px solid var(--line2);border-left:4px solid var(--violet);
  border-radius:13px;background:color-mix(in oklab,var(--violet) 6%,var(--panel));overflow:hidden}
.ex-head{display:flex;align-items:center;gap:11px;padding:13px 16px 6px}
.ex-title{font-family:var(--display);font-weight:700;font-size:16px;color:var(--violet)}
.enunciado{padding:0 16px 8px}
.enunciado .bloco-p:first-child{margin-top:4px}
.btn-revelar{margin:6px 16px 14px;font-family:var(--display);font-weight:600;font-size:14px;
  color:#04121f;background:linear-gradient(135deg,var(--violet),var(--blue));border:none;border-radius:10px;
  padding:10px 16px;cursor:pointer;transition:filter .15s,transform .05s;box-shadow:0 4px 14px rgba(155,140,255,.22)}
.btn-revelar:hover{filter:brightness(1.08)} .btn-revelar:active{transform:translateY(1px)}
.solucao{margin:0 14px 14px;padding:6px 14px 4px;border-top:1px dashed var(--line2);
  background:color-mix(in oklab,var(--bg) 55%,transparent);border-radius:0 0 10px 10px}
.solucao[hidden]{display:none}
.ex-tools{display:flex;gap:8px;margin:0 0 12px}
.ex-tools button{font-family:var(--mono);font-size:11px;color:var(--ink-soft);background:var(--panel2);border:1px solid var(--line2);border-radius:7px;padding:6px 10px;cursor:pointer}
.ex-tools button:hover{border-color:var(--violet);color:var(--ink)}

/* progress checkbox */
.progress-check{flex:0 0 auto;width:21px;height:21px;border-radius:6px;border:1.6px solid var(--line2);
  background:transparent;cursor:pointer;position:relative;transition:.15s;margin-top:2px}
.progress-check:hover{border-color:var(--cyan)}
.progress-check.done{background:linear-gradient(135deg,var(--green),var(--cyan));border-color:transparent}
.progress-check.done::after{content:"✓";position:absolute;inset:0;display:grid;place-items:center;color:#04121f;font-size:13px;font-weight:900}
h2.secao .progress-check,h3.secao .progress-check{margin-top:3px}

/* figures */
.figura{margin:20px 0;padding:14px;border:1px solid var(--line);border-radius:12px;background:var(--panel2);text-align:center}
.figura svg{max-width:100%;height:auto}
.figura figcaption{font-family:var(--body);font-size:13.5px;color:var(--ink-soft);margin-top:10px;font-style:italic;line-height:1.5}
.figura .fig-ph{font-family:var(--mono);font-size:12.5px;color:var(--ink-dim);padding:18px 10px;border:1px dashed var(--line2);border-radius:9px}

/* tabelas */
.tab-wrap{margin:18px 0;overflow-x:auto;border:1px solid var(--line2);border-radius:12px;background:var(--panel)}
.tab{border-collapse:collapse;width:100%;font-size:15.5px}
.tab th,.tab td{padding:10px 16px;text-align:left;border-bottom:1px solid var(--line);vertical-align:middle}
.tab th{font-family:var(--display);font-weight:700;color:var(--cyan);background:var(--panel2);font-size:14px;position:sticky;top:0}
.tab tr:last-child td{border-bottom:none}
.tab tr:hover td{background:color-mix(in oklab,var(--blue) 6%,transparent)}
.tab-cap{display:block;font-size:13.5px;color:var(--ink-dim);font-style:italic;text-align:center;margin:-8px 0 14px}

/* media-in-context */
.midia-ctx{margin:34px 0 10px;padding-top:22px;border-top:1px solid var(--line)}
.midia-h{font-family:var(--display);font-weight:700;font-size:18px;margin:0 0 14px;color:var(--cyan)}
.midia-card{margin:0 0 18px;background:var(--panel);border:1px solid var(--line2);border-radius:13px;overflow:hidden}
.midia-cap{font-family:var(--mono);font-size:12px;letter-spacing:.03em;color:var(--ink-soft);padding:10px 14px;border-bottom:1px solid var(--line);background:var(--panel2)}
.midia-card video{display:block;width:100%;background:#000}
.explorador-wrap{display:flex;flex-direction:column}
.explorador-wrap iframe{width:100%;height:520px;border:none;background:var(--bg)}
.btn-explorador{display:block;text-align:center;font-family:var(--display);font-weight:600;font-size:14px;
  padding:12px;color:var(--cyan);background:var(--panel2);border-top:1px solid var(--line);text-decoration:none}
.btn-explorador:hover{background:var(--panel);color:var(--ink)}

/* chapter nav */
#cap-nav{max-width:var(--read-w);margin:0 auto;width:100%;padding:10px 26px 50px;display:flex;justify-content:space-between;gap:12px}
.capnav-btn{font-family:var(--display);font-weight:600;font-size:14px;color:var(--ink);background:var(--panel2);border:1px solid var(--line2);border-radius:10px;padding:11px 18px;cursor:pointer;transition:.15s}
.capnav-btn:hover{border-color:var(--cyan);color:var(--cyan)}

/* scrim for mobile nav */
#scrim{display:none;position:fixed;inset:0;background:rgba(2,6,14,.55);z-index:35}

/* ----------------------------- RESPONSIVE ----------------------------- */
@media (max-width:860px){
  :root{--sidebar-w:300px}
  #sidebar{transform:translateX(-100%);transition:transform .25s ease;box-shadow:var(--shadow)}
  body.nav-open #sidebar{transform:none}
  body.nav-open #scrim{display:block}
  #reader{margin-left:0}
  .icon-btn{display:grid;place-items:center}
  #conteudo{padding:22px 16px 36px}
  .cap-title{font-size:27px}
  .explorador-wrap iframe{height:60vw;min-height:340px}
}
@media (prefers-reduced-motion:reduce){*{transition:none!important;animation:none!important}}