/*!
 * SciParaTodos · Simulador de las Leyes de Newton — estilos
 */
:root{
  --bg:#eef4fb; --bg2:#e3ecf7; --card:#fff; --tx:#10233f; --tx2:#4b5b72; --tx3:#6b7a90; --line:#dbe3ee;
  --acc:#6d4ae8; --acc2:#f1ecff; --red:#e5484d; --navy:#0f1c3a;
  --cK:#1586b5; --cU:#0f9f6e; --cQ:#e8833a; --cE:#6d4ae8; --cT:#10233f;
  --ok:#0f8a5f; --okbg:#e6f6ef; --warn:#b45309; --warnbg:#fff4e5; --bad:#c2410c; --badbg:#fff1ec;
  --r:18px; --mono:'JetBrains Mono',ui-monospace,Consolas,monospace;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--tx);font-family:'Nunito Sans',system-ui,-apple-system,'Segoe UI',Roboto,Arial,sans-serif;font-size:16px;line-height:1.55}
.wrap{max-width:1320px;margin:0 auto;padding:0 28px}
button,input,select{font:inherit;color:inherit}
a{color:var(--acc)}
img{max-width:100%}

/* ---------- navegación ---------- */
.nav{position:sticky;top:0;z-index:20;background:rgba(255,255,255,.92);backdrop-filter:saturate(1.4) blur(10px);-webkit-backdrop-filter:saturate(1.4) blur(10px);border-bottom:1px solid var(--line)}
.nav-in{display:flex;align-items:center;gap:20px;min-height:72px}
.brand{display:flex;align-items:center;gap:12px;text-decoration:none;color:var(--tx)}
.logo{height:52px;width:auto}
.logo.sm{height:36px}
.brand-tx{display:flex;flex-direction:column;line-height:1.25}
.brand-tx b{font-weight:800;font-size:15px}
.brand-tx small{color:var(--tx3);font-size:13px}
.links{display:flex;gap:4px;margin-left:auto}
.links a{text-decoration:none;color:var(--tx2);font-weight:700;font-size:15px;padding:8px 12px;border-radius:10px}
.links a:hover{background:var(--acc2);color:var(--acc)}
.lang{display:flex;gap:6px}
.lang button{min-width:44px;height:40px;border-radius:12px;border:1px solid var(--line);background:#fff;font-weight:800;cursor:pointer}
.lang button.on{background:var(--acc);color:#fff;border-color:var(--acc)}

/* ---------- hero ---------- */
.hero{position:relative;overflow:hidden;color:#fff;
  background:radial-gradient(1200px 500px at 85% 10%,rgba(109,74,232,.45),transparent 60%),
             radial-gradient(900px 500px at 0% 100%,rgba(21,134,181,.35),transparent 60%),
             linear-gradient(160deg,#0b1430 0%,#13224a 55%,#1b2f63 100%)}
.hero-in{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1.05fr);gap:34px;align-items:center;padding:64px 28px 72px}
.tag{display:inline-block;background:rgba(255,255,255,.12);border:1px solid rgba(255,255,255,.22);padding:6px 14px;border-radius:999px;font-weight:700;font-size:13px;letter-spacing:.04em}
.hero h1{font-size:clamp(32px,5vw,56px);line-height:1.06;margin:18px 0 16px;font-weight:900;letter-spacing:-.01em}
.hero .lead{font-size:18px;color:#d6def0;margin:0 0 16px;max-width:620px}
.hero .lead b{color:#fff}
.autores{margin:0 0 26px;font-weight:700;color:#bcc8e4;font-size:15px}
.cta{display:flex;flex-wrap:wrap;gap:12px}
.chips{list-style:none;display:flex;flex-wrap:wrap;gap:10px;padding:0;margin:26px 0 0}
.chips li{font-size:14px;font-weight:700;color:#d6def0;background:rgba(255,255,255,.08);border:1px solid rgba(255,255,255,.14);padding:6px 12px;border-radius:10px}
.hero-img img{display:block;width:100%;height:auto;border-radius:22px;box-shadow:0 30px 60px -20px rgba(0,0,0,.55),0 0 0 1px rgba(255,255,255,.08)}

/* ---------- botones ---------- */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;border:1px solid var(--line);background:#fff;border-radius:12px;padding:10px 16px;font-weight:800;cursor:pointer;text-decoration:none;color:var(--tx);transition:transform .08s,box-shadow .15s}
.btn:hover{box-shadow:0 4px 14px -6px rgba(16,35,63,.35)}
.btn:active{transform:translateY(1px)}
.btn.pri{background:var(--acc);border-color:var(--acc);color:#fff}
.btn.ghost{background:transparent;border-color:rgba(255,255,255,.4);color:#fff}
.btn.big{padding:14px 22px;font-size:17px;border-radius:14px}

/* ---------- secciones ---------- */
.sec{padding:72px 0}
.sec.alt{background:var(--bg2)}
.sh{max-width:760px;margin:0 0 30px}
.stag{color:#1a7fa3;font-weight:900;letter-spacing:.14em;text-transform:uppercase;font-size:13px}
.sh h2{font-size:clamp(26px,3.4vw,38px);line-height:1.15;margin:6px 0 8px;font-weight:900}
.sh p{margin:0;color:var(--tx2)}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:22px;box-shadow:0 1px 2px rgba(16,35,63,.04)}
.card h3{margin:0 0 14px;font-size:19px;font-weight:900}

/* ---------- laboratorio ---------- */
.lab{display:grid;grid-template-columns:minmax(0,1fr) 340px;gap:20px;align-items:start}
.escena{padding:14px}
.lienzo{position:relative;border-radius:14px;overflow:hidden;background:#bfe3fa}
#cv{display:block;width:100%;height:auto;aspect-ratio:2/1}
.reloj{position:absolute;top:12px;right:12px;font-family:var(--mono);font-weight:700;font-size:clamp(16px,2.4vw,26px);color:#fff;background:rgba(15,28,58,.82);padding:6px 14px;border-radius:12px;letter-spacing:.06em}
.estado{position:absolute;top:12px;left:12px;font-size:13px;font-weight:800;color:#fff;background:rgba(15,28,58,.7);padding:5px 11px;border-radius:999px}
.mensaje{position:absolute;left:12px;right:12px;bottom:12px;font-weight:700;font-size:14px;border-radius:12px;padding:10px 14px;display:none}
.mensaje.ok{display:block;background:rgba(230,246,239,.96);color:#0b5c40}
.mensaje.info{display:block;background:rgba(255,255,255,.95);color:var(--tx)}
.mensaje.bad{display:block;background:rgba(255,241,236,.97);color:#9a3412}
.lecturas{display:grid;grid-template-columns:repeat(6,minmax(0,1fr));gap:8px;margin-top:12px}
.lecturas div{background:#f4f7fb;border-radius:12px;padding:8px 10px;min-width:0}
.lecturas span{display:block;font-size:12px;color:var(--tx3);font-weight:700;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.lecturas b{font-family:var(--mono);font-size:15px;white-space:nowrap}

.panel{background:linear-gradient(180deg,#14234a,#0f1c3a);color:#e6ecf8;border-color:#1f3263}
.panel h3{color:#fff;margin:0}
.panel-h{display:flex;justify-content:space-between;align-items:center;margin-bottom:14px}
.badge{font-size:11px;font-weight:900;letter-spacing:.08em;text-transform:uppercase;background:rgba(255,255,255,.14);padding:4px 10px;border-radius:999px}
.badge.run{background:#0f9f6e;color:#fff}
.badge.end{background:#6d4ae8;color:#fff}
.botones{display:grid;grid-template-columns:1fr 48px;gap:8px}
.botones .btn{padding:11px}
#b-play{background:#fff;color:var(--navy);border-color:#fff}
#b-reset{background:transparent;color:#fff;border-color:rgba(255,255,255,.3);font-size:18px}
.vel{display:grid;grid-template-columns:repeat(4,1fr);gap:4px;margin:10px 0 14px;background:rgba(255,255,255,.06);padding:4px;border-radius:12px}
.vel button{border:0;background:transparent;color:#c9d5ea;font-weight:800;border-radius:9px;padding:6px 0;cursor:pointer}
.vel button.on{background:#fff;color:var(--navy)}
.campo{display:block;margin:0 0 12px}
.campo span{display:block;font-size:13px;font-weight:700;margin-bottom:5px;color:#c9d5ea}
.campo select{width:100%;padding:9px 10px;border-radius:10px;border:1px solid rgba(255,255,255,.18);background:#1b2c57;color:#fff}
.desl{margin:0 0 10px;padding-top:8px;border-top:1px solid rgba(255,255,255,.08)}
.dl-h{display:flex;justify-content:space-between;font-size:13px;font-weight:700;color:#c9d5ea}
.dl-h b{color:#7ee2b8;font-family:var(--mono);font-size:13px}
.desl input{width:100%;accent-color:#8f74ff;margin:6px 0 0}
.chks{display:flex;flex-wrap:wrap;gap:8px 14px;margin:8px 0 6px}
.chk{display:flex;align-items:center;gap:6px;font-size:14px;font-weight:700;cursor:pointer}
.chk input{width:16px;height:16px;accent-color:#8f74ff}
.hmin{font-size:13px;color:#c9d5ea;margin:8px 0 0;background:rgba(255,255,255,.06);border-radius:10px;padding:8px 10px}
.hmin b{color:#fff}

.izq{display:grid;gap:20px;min-width:0}
.lab2{display:grid;grid-template-columns:minmax(0,1fr);gap:20px;margin-top:20px}

.barras{display:flex;flex-direction:column;gap:10px}
.barra{display:grid;grid-template-columns:150px minmax(0,1fr) 96px;gap:10px;align-items:center;font-size:14px}
.barra .nm{font-weight:700;color:var(--tx2)}
.barra .tr{height:16px;background:#eef2f8;border-radius:999px;overflow:hidden}
.barra .fl{height:100%;border-radius:999px;transition:width .05s linear}
.barra .vl{font-family:var(--mono);font-size:13px;text-align:right}
.nota{color:var(--tx2);font-size:14px;margin:12px 0 0}
.tabs{display:flex;flex-wrap:wrap;gap:6px;margin-bottom:12px}
.tabs button{border:1px solid var(--line);background:#fff;border-radius:999px;padding:6px 14px;font-weight:800;font-size:14px;cursor:pointer;color:var(--tx2)}
.tabs button.on{background:var(--acc);border-color:var(--acc);color:#fff}
.graf{display:block;width:100%}

.leyenda{display:flex;flex-wrap:wrap;gap:14px;font-size:13px;margin-top:6px}
.leyenda i{display:inline-block;width:18px;height:3px;border-radius:2px;vertical-align:middle;margin-right:5px}

.pred{margin-top:20px}
.formulas{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:12px}
.formulas div{background:var(--acc2);color:#3b2a8f;font-weight:700;font-size:14px;border-radius:10px;padding:6px 12px}
.tscroll{overflow-x:auto}
.pred table{width:100%;border-collapse:collapse;font-size:14px;min-width:720px}
.pred th,.pred td{padding:9px 8px;border-bottom:1px solid var(--line);text-align:right;white-space:nowrap}
.pred th:first-child,.pred td:first-child{text-align:left}
.pred th{background:#f4f7fb;font-weight:800}
.pred td{font-family:var(--mono);font-size:13px}
.pred td:first-child{font-family:inherit;font-size:14px;font-weight:700}
.pred td.ok{color:var(--ok)}
.pred td.muted{color:var(--tx3)}
.acts{display:flex;flex-wrap:wrap;gap:10px;margin-top:14px}
.foot{color:var(--tx3);font-size:13px;margin:18px 0 0}

/* ---------- teoría ---------- */
.cards3{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px}
.tc{background:#fff;border:1px solid var(--line);border-radius:var(--r);padding:22px}
.tc h3{margin:12px 0 8px;font-size:18px;font-weight:900}
.tc p{margin:0;color:var(--tx2)}
.tc p b{color:var(--tx)}
.ico{width:46px;height:46px;border-radius:14px;display:grid;place-items:center;font-weight:900;font-size:20px;color:#fff;background:linear-gradient(135deg,var(--acc),#1586b5);font-style:italic}
.figs{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin-top:18px}
.figs figure{margin:0}
.figs svg{width:100%;height:auto;display:block}
.figs figcaption{color:var(--tx2);font-size:14px;margin-top:8px}

/* ---------- actividades ---------- */
.act .ac{background:#fff;border:1px solid var(--line);border-radius:var(--r);padding:22px;display:flex;flex-direction:column}
.ac .num{font-weight:900;color:var(--acc);font-size:13px;letter-spacing:.1em}
.ac h3{margin:4px 0 12px;font-size:18px;font-weight:900}
.ac h4{margin:10px 0 6px;font-size:14px;font-weight:900;color:var(--tx2);text-transform:uppercase;letter-spacing:.06em}
.ac ol,.ac ul{margin:0;padding-left:20px;color:var(--tx2)}
.ac li{margin:3px 0}
.ac .btn{margin-top:auto;align-self:flex-start}
.ac .esp{flex:1;min-height:14px}

/* ---------- preguntas ---------- */
.faq{display:grid;gap:12px;max-width:900px}
.faq details{background:#fff;border:1px solid var(--line);border-radius:14px;padding:16px 20px}
.faq summary{font-weight:800;cursor:pointer;font-size:17px}
.faq p{margin:10px 0 0;color:var(--tx2)}

/* ---------- pie ---------- */
.ft{background:var(--navy);color:#c9d5e4;padding:40px 0 28px}
.ft-in{display:grid;grid-template-columns:1fr auto;gap:20px}
.ft .brand{color:#fff}
.ft p{margin:10px 0 0;max-width:460px;font-size:14px}
.ft-links{display:flex;flex-wrap:wrap;gap:16px;align-items:flex-start}
.ft-links a{color:#fff;text-decoration:none;font-weight:700;font-size:14px}
.copy{grid-column:1/-1;border-top:1px solid rgba(255,255,255,.12);padding-top:16px;font-size:13px}

/* ---------- responsivo ---------- */
@media (max-width:1100px){
  .lab{grid-template-columns:minmax(0,1fr)}
  .lab2{grid-template-columns:minmax(0,1fr)}
  .lecturas{grid-template-columns:repeat(3,minmax(0,1fr))}
}
@media (max-width:900px){
  .hero-in{grid-template-columns:minmax(0,1fr);padding:44px 28px 52px}
  .cards3{grid-template-columns:repeat(2,minmax(0,1fr))}
  .figs{grid-template-columns:minmax(0,1fr)}
  .links{display:none}
  .lang{margin-left:auto}
}
@media (max-width:600px){
  .wrap{padding:0 16px}
  .hero-in{padding:36px 16px 44px}
  .cards3{grid-template-columns:minmax(0,1fr)}
  .lecturas{grid-template-columns:repeat(2,minmax(0,1fr))}
  .barra{grid-template-columns:110px minmax(0,1fr) 84px;font-size:13px}
  .sec{padding:52px 0}
  .card{padding:16px}
  .ft-in{grid-template-columns:minmax(0,1fr)}
  .logo{height:42px}
  .reloj{font-size:13px;padding:3px 8px;top:6px;right:6px}
  .estado{display:none}
  .mensaje{font-size:12px;padding:6px 9px;left:6px;right:6px;bottom:6px}
  .escena{padding:8px}
}

/* ---------- plano inclinado ---------- */
.dos-col{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:20px}
.fuerzas{width:100%;border-collapse:collapse;font-size:14px}
.fuerzas td{padding:7px 4px;border-bottom:1px solid var(--line)}
.fuerzas td.num{font-family:var(--mono);font-size:13px;text-align:right;white-space:nowrap}
.fuerzas td.dir{color:var(--tx3);font-size:12px;text-align:right;white-space:nowrap;padding-left:8px}
.fuerzas tr.net td{font-weight:800;border-bottom:0;background:var(--acc2)}
.dos-col .barra{grid-template-columns:118px minmax(0,1fr) 78px;font-size:13px}
.pred td.frm{font-family:inherit;font-size:13px;color:#3b2a8f;text-align:left}
.pred table{min-width:640px}
.lecturas b{font-size:14px}
@media (max-width:1300px){ .dos-col{grid-template-columns:minmax(0,1fr)} }
.pred th:nth-child(2){text-align:left}
@media (max-width:600px){.lienzo .mensaje{position:static;border-radius:0}}

/* ---------- torque ---------- */
.paleta{display:flex;flex-wrap:wrap;align-items:center;gap:10px;margin-top:12px}
.paleta h4{margin:0 8px 0 0;font-size:14px;font-weight:800;color:var(--tx2)}
.chip{width:62px;height:56px;border-radius:14px;border:0;color:#fff;font-weight:900;font-size:16px;cursor:grab;touch-action:none;user-select:none;box-shadow:0 6px 14px -8px rgba(16,35,63,.55);display:grid;place-items:center}
.chip:active{cursor:grabbing}
.chip.c1{background:#3b82f6}.chip.c2{background:#22c55e}.chip.c5{background:#eab308}.chip.c10{background:#ef4444}.chip.cx{background:#8f74ff}
.chip-x{display:flex;align-items:center;gap:6px}
.chip-x input{width:76px;padding:8px;border:1px solid var(--line);border-radius:10px;font-family:var(--mono);font-size:14px}
.ayuda2{color:var(--tx3);font-size:13px;margin:8px 0 0}
.fantasma{position:fixed;z-index:50;pointer-events:none;transform:translate(-50%,-50%);opacity:.9}
.fantasma.fuera{opacity:.45;filter:grayscale(1)}
.tt{width:100%;border-collapse:collapse;font-size:14px}
.tt th{background:#f4f7fb;font-weight:800;padding:8px 6px;text-align:right;white-space:nowrap}
.tt th:first-child,.tt td:first-child{text-align:left}
.tt td{padding:6px;border-bottom:1px solid var(--line);text-align:right;white-space:nowrap}
.tt td.num{font-family:var(--mono);font-size:13px}
.tt td input{width:74px;padding:5px 6px;border:1px solid var(--line);border-radius:8px;font-family:var(--mono);font-size:13px;text-align:right}
.tt td .del{width:28px;height:28px;border-radius:8px;border:1px solid var(--line);background:#fff;color:var(--bad);cursor:pointer}
.tt tfoot td{font-weight:800;background:#f8fafd}
.tt tr.tot td{background:var(--acc2)}
.pt{display:inline-block;width:12px;height:12px;border-radius:4px;vertical-align:middle;margin-right:6px}
.sent{font-size:12px;color:var(--tx3)}
.estado-eq{display:flex;align-items:center;gap:10px;border-radius:14px;padding:12px 14px;font-weight:800;margin-bottom:12px}
.estado-eq.si{background:var(--okbg);color:#0b5c40}
.estado-eq.no{background:var(--warnbg);color:#7a3e06}
.fz{border-top:1px solid rgba(255,255,255,.12);margin-top:10px;padding-top:8px}
.fz .chk{margin-bottom:4px}
.fz .desl{border-top:0;padding-top:2px}
.campo2{display:grid;grid-template-columns:1fr 1fr;gap:8px}
#cv.arr{cursor:grab}
#cv{touch-action:pan-y}
.izq>*{min-width:0}

/* ---------- Newton ---------- */
.modos{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:10px;margin-bottom:18px}
.modos button{border:2px solid var(--line);background:#fff;border-radius:16px;padding:14px 16px;text-align:left;cursor:pointer;color:var(--tx)}
.modos button b{display:block;font-size:16px;font-weight:900}
.modos button span{display:block;font-size:13px;color:var(--tx3);margin-top:2px}
.modos button.on{border-color:var(--acc);background:var(--acc2);box-shadow:0 6px 18px -10px rgba(109,74,232,.6)}
.modos button.on b{color:var(--acc)}
.grupo{display:none}
.grupo.on{display:block}
.fza-btn{display:flex;gap:10px;margin-top:12px;flex-wrap:wrap}
.fza-btn .btn{flex:1;min-width:180px}
.btn.fza-on{background:#1586b5;border-color:#1586b5;color:#fff}
.dcl-card{display:grid;grid-template-columns:minmax(0,1fr);gap:8px}
.dcl-top{display:flex;justify-content:space-between;align-items:center;gap:10px;flex-wrap:wrap}
.dcl-top h3{margin:0}
#dcl{width:100%;height:auto;display:block;aspect-ratio:1/1;max-height:340px;background:#f8fafd;border-radius:14px}
.sel-cuerpo{display:flex;gap:4px;background:#f4f7fb;border-radius:10px;padding:3px}
.sel-cuerpo button{border:0;background:transparent;border-radius:8px;padding:5px 10px;font-weight:800;font-size:13px;cursor:pointer;color:var(--tx2)}
.sel-cuerpo button.on{background:var(--acc);color:#fff}
.sumas{font-family:var(--mono);font-size:13px;color:var(--tx2);margin:0}
.sumas b{color:var(--tx)}
.lab .izq .dos-col{grid-template-columns:minmax(0,7fr) minmax(0,6fr)}
@media (max-width:1300px){ .lab .izq .dos-col{grid-template-columns:minmax(0,1fr)} }
@media (max-width:700px){ .modos{grid-template-columns:minmax(0,1fr)} }
.fza-btn.grupo:not(.on){display:none}