:root{
  color-scheme:light dark;
  --bg:light-dark(#f5f6fb,#0a0c16);
  --surface:light-dark(#fff,#12162a);
  --surface-2:light-dark(#f0f2f9,#1a1f38);
  --text:light-dark(#151933,#e9ecfb);
  --muted:light-dark(#5d6384,#97a0c4);
  --border:light-dark(#e1e4f1,#262c4a);
  --brand:light-dark(#4f46e5,#6a62f5);
  --brand-soft:light-dark(#eceaff,#23224f);
  --chem:light-dark(#4f46e5,#9a95ff);
  --bio:light-dark(#059669,#34d399);
  --ok:light-dark(#047857,#6ee7b7);--ok-bg:light-dark(#e8faf2,#0f2a22);--ok-bd:light-dark(#7fd8b4,#1d5a45);
  --bad:light-dark(#be123c,#fda4af);--bad-bg:light-dark(#fff0f3,#33141e);--bad-bd:light-dark(#f2a1b3,#6b2535);
  --warn:light-dark(#b45309,#d97706);
  --shadow:0 12px 32px -14px light-dark(rgba(40,40,110,.28),rgba(0,0,0,.7));
}
:root[data-theme=light]{color-scheme:light}
:root[data-theme=dark]{color-scheme:dark}

*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--text);font:16px/1.55 Inter,system-ui,sans-serif;transition:background .25s,color .25s;padding-bottom:90px}
h1,h2{line-height:1.2;letter-spacing:-.02em;margin:0}
h1{font-size:1.9rem;font-weight:800}
h2{font-size:1.35rem;font-weight:700}
button,input,textarea{font:inherit;color:inherit}
button{cursor:pointer}
[hidden]{display:none!important}
.wrap{max-width:860px;margin:0 auto;padding:0 16px}
main.wrap{padding-top:24px}
.muted{color:var(--muted)}.small{font-size:.85rem}
.row{display:flex;align-items:center;gap:12px}.between{justify-content:space-between}.end{justify-content:flex-end;margin-top:20px}.center{justify-content:center}.wrapflex{flex-wrap:wrap}

.topbar{position:sticky;top:0;z-index:20;background:color-mix(in srgb,var(--surface) 82%,transparent);backdrop-filter:blur(14px);-webkit-backdrop-filter:blur(14px);border-bottom:1px solid var(--border)}
.bar{display:flex;align-items:center;justify-content:space-between;height:62px;gap:10px}
.brand{display:flex;align-items:center;gap:10px}
.brand small{display:block;color:var(--muted);font-size:.72rem;line-height:1.1}
.logo{width:38px;height:38px;border-radius:12px;background:var(--brand);color:#fff;display:grid;place-items:center}
.stats{display:flex;gap:8px;margin-left:auto}
.chip{background:var(--surface-2);border:1px solid var(--border);border-radius:10px;padding:4px 10px;font-size:.82rem;font-weight:600;white-space:nowrap}
.chip i{color:#f59e0b}
.icon-btn{width:40px;height:40px;border-radius:12px;border:1px solid var(--border);background:var(--surface-2);display:grid;place-items:center}
.icon-btn:hover{background:var(--brand-soft)}

.card{background:var(--surface);border:1px solid var(--border);border-radius:20px;padding:24px;box-shadow:var(--shadow);margin-bottom:16px;animation:in .35s cubic-bezier(.16,1,.3,1)}
@keyframes in{from{opacity:0;transform:translateY(8px)}}
.hero{display:grid;gap:18px}
.field{display:grid;gap:8px}
.label{font-size:.75rem;font-weight:700;text-transform:uppercase;letter-spacing:.08em;color:var(--muted)}
.seg{display:flex;flex-wrap:wrap;gap:6px;background:var(--surface-2);border:1px solid var(--border);border-radius:14px;padding:5px}
.seg button{flex:1 1 auto;border:0;background:transparent;border-radius:10px;padding:10px 14px;font-weight:600;color:var(--muted);transition:.15s}
.seg button[aria-pressed=true]{background:var(--brand);color:#fff;box-shadow:0 4px 12px -4px var(--brand)}

.btn{border:0;border-radius:14px;padding:12px 20px;font-weight:700;display:inline-flex;align-items:center;justify-content:center;gap:8px;transition:.15s}
.btn.primary{background:var(--brand);color:#fff}.btn.primary:hover{filter:brightness(1.1)}
.btn.warn{background:var(--warn);color:#fff}
.btn.big{padding:15px 24px;font-size:1.05rem}
.btn:disabled{opacity:.45;cursor:not-allowed}
:focus-visible{outline:3px solid color-mix(in srgb,var(--brand) 60%,transparent);outline-offset:2px}

.progress{padding:16px}
.tag{font-weight:700;font-size:.75rem;text-transform:uppercase;letter-spacing:.06em;padding:4px 10px;border-radius:8px;background:var(--brand-soft);color:var(--accent,var(--brand))}
.bar-track{height:9px;border-radius:99px;background:var(--surface-2);overflow:hidden;margin-top:10px}
.bar-track>div{height:100%;width:0;border-radius:99px;background:var(--brand);transition:width .4s}
.fill-chem{background:var(--chem)!important}.fill-bio{background:var(--bio)!important}
.chem{color:var(--chem);font-weight:700}.bio{color:var(--bio);font-weight:700}

.question{--accent:var(--brand)}
.question[data-subject=Chimica]{--accent:var(--chem)}
.question[data-subject=Biologia]{--accent:var(--bio)}
.subtopic{display:inline-flex;gap:8px;align-items:center;font-size:.75rem;font-weight:700;text-transform:uppercase;letter-spacing:.07em;color:var(--accent);margin-bottom:10px}
.problem{margin:16px 0;padding:14px 16px;border-radius:14px;background:var(--surface-2);border:1px solid var(--border);border-left:4px solid var(--accent)}
.options{display:grid;gap:10px;margin-top:18px}
.option{display:flex;gap:12px;align-items:flex-start;text-align:left;width:100%;padding:14px;border-radius:14px;border:1.5px solid var(--border);background:var(--surface-2);font-weight:500;transition:.15s}
.option:hover:not(:disabled){border-color:var(--accent);transform:translateY(-1px)}
.letter{flex:none;width:26px;height:26px;border-radius:50%;border:1.5px solid var(--border);display:grid;place-items:center;font-size:.75rem;font-weight:700;color:var(--muted)}
.option:disabled{cursor:default}
.option.correct{background:var(--ok-bg);border-color:var(--ok-bd)}.option.correct .letter{background:var(--ok);border-color:var(--ok);color:var(--ok-bg)}
.option.wrong{background:var(--bad-bg);border-color:var(--bad-bd)}.option.wrong .letter{background:var(--bad);border-color:var(--bad);color:var(--bad-bg)}

.numeric,.open-box{display:grid;gap:12px;margin-top:18px}
.numeric input{width:min(260px,100%);padding:13px 16px;border-radius:14px;border:1.5px solid var(--border);background:var(--surface-2);font-weight:700;font-size:1.1rem}
.numeric input:focus,.open-box textarea:focus{outline:none;border-color:var(--accent)}
.open-box textarea{width:100%;padding:13px 16px;border-radius:14px;border:1.5px solid var(--border);background:var(--surface-2);resize:vertical;min-height:92px}
.open-box .btn,.numeric .btn{justify-self:start}
.unit{font-weight:700;color:var(--muted)}
.error{color:var(--bad);font-size:.88rem;margin:0}

.explain{margin-top:20px;padding:16px 18px;border-radius:14px;border:1px solid;animation:in .3s}
.explain.ok{background:var(--ok-bg);border-color:var(--ok-bd);color:var(--ok)}
.explain.ko{background:var(--bad-bg);border-color:var(--bad-bd);color:var(--bad)}
.explain-head{font-weight:800;margin-bottom:6px}
.explain p{margin:0;color:var(--text);font-size:.95rem}

mjx-container{color:inherit}
mjx-container[display=true]{overflow-x:auto;overflow-y:hidden;max-width:100%;margin:.7em 0!important;padding:.2em 0}

.summary{text-align:center;display:grid;gap:18px}
.medal{width:72px;height:72px;margin:0 auto;border-radius:50%;display:grid;place-items:center;font-size:2rem;background:var(--ok-bg);color:var(--ok)}
.scores{display:grid;grid-template-columns:1fr 1fr;gap:12px;max-width:420px;margin:0 auto;width:100%}
.scores div{background:var(--surface-2);border:1px solid var(--border);border-radius:16px;padding:14px}
.scores small{display:block;color:var(--muted);font-weight:700;text-transform:uppercase;font-size:.7rem;letter-spacing:.08em}
.scores strong{font-size:1.9rem;font-weight:800;color:var(--brand)}
.breakdown{display:grid;gap:14px;max-width:520px;margin:0 auto;width:100%;text-align:left}
.feedback{font-style:italic;color:var(--muted);max-width:520px;margin:0 auto}

#chat-fab{position:fixed;right:20px;bottom:20px;z-index:40;width:56px;height:56px;border:0;border-radius:50%;padding:0;display:grid;place-items:center;background:var(--brand);color:#fff;font-size:1.35rem;box-shadow:0 10px 28px -6px var(--brand);transition:transform .2s,filter .2s}
#chat-fab:hover{transform:scale(1.07);filter:brightness(1.1)}
#chat{position:fixed;right:16px;bottom:16px;z-index:50;width:min(390px,calc(100vw - 32px));height:min(560px,calc(100dvh - 90px));display:flex;flex-direction:column;background:var(--surface);border:1px solid var(--border);border-radius:20px;box-shadow:0 24px 60px -20px rgba(0,0,0,.45);overflow:hidden;animation:in .25s;transition:width .25s,height .25s,right .25s,bottom .25s,border-radius .25s}
#chat.fullscreen{right:0;bottom:0;width:100vw;height:100dvh;border-radius:0;border:0}
#chat>header{display:flex;align-items:center;gap:8px;padding:12px 14px;border-bottom:1px solid var(--border);background:var(--surface-2)}
#chat>header div{flex:1;line-height:1.2}#chat>header small{display:block;color:var(--muted);font-size:.72rem}
#chat .icon-btn{width:34px;height:34px;border-radius:10px}
#chat-log{flex:1;overflow-y:auto;padding:14px;display:flex;flex-direction:column;gap:10px;scroll-behavior:smooth}
.msg{max-width:88%;padding:10px 13px;border-radius:16px;font-size:.92rem;overflow-wrap:anywhere}
.msg.bot{background:var(--surface-2);border:1px solid var(--border);border-bottom-left-radius:4px;align-self:flex-start}
.msg.user{background:var(--brand);color:#fff;border-bottom-right-radius:4px;align-self:flex-end}
.msg.err{border-color:var(--bad-bd);color:var(--bad)}
.msg code{background:var(--brand-soft);padding:1px 5px;border-radius:5px}
.msg mjx-container[display=true]{margin:.4em 0!important}
.typing{display:inline-flex;gap:4px}.typing i{width:7px;height:7px;border-radius:50%;background:var(--muted);animation:b 1s infinite}.typing i:nth-child(2){animation-delay:.15s}.typing i:nth-child(3){animation-delay:.3s}
@keyframes b{50%{transform:translateY(-4px);opacity:.4}}
.chips{display:flex;gap:6px;padding:0 14px 8px;overflow-x:auto}
.chips button{flex:none;border:1px solid var(--border);background:var(--surface);border-radius:99px;padding:6px 12px;font-size:.8rem;font-weight:600;color:var(--muted)}
.chips button:hover{color:var(--brand);border-color:var(--brand)}
#chat-form{display:flex;gap:8px;padding:10px 12px;border-top:1px solid var(--border);align-items:flex-end}
#chat-input{flex:1;resize:none;max-height:110px;padding:10px 12px;border-radius:14px;border:1.5px solid var(--border);background:var(--surface-2)}
#chat-input:focus{outline:none;border-color:var(--brand)}
#chat-form .btn{padding:11px 14px}

@media (max-width:560px){
  h1{font-size:1.55rem}.card{padding:18px;border-radius:18px}
  .brand small{display:none}
  #chat:not(.fullscreen){right:0;bottom:0;width:100vw;height:82dvh;border-radius:20px 20px 0 0}
}
@media (prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important}}