/*!
 * SciParaTodos · Simulador de Colisiones 1D — estilos
 */
html{scroll-behavior:smooth}
body{margin:0;background:#f1f5f9}
#spt-col{--bg:#f1f5f9;--card:#ffffff;--ink:#0f172a;--mut:#64748b;--line:#e2e8f0;--c1:#ef4444;--c2:#10b981;--tot:#2563eb;--cm:#f59e0b;--acc:#2563eb;
  font-family:system-ui,-apple-system,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;color:var(--ink);max-width:none;margin:0;padding:0;box-sizing:border-box;line-height:1.5;background:var(--bg)}
#spt-col *{box-sizing:border-box}
#spt-col .card{background:var(--card);border:1px solid var(--line);border-radius:14px;box-shadow:0 1px 2px rgba(15,23,42,.04),0 6px 20px rgba(15,23,42,.05)}
#spt-col .hd{display:flex;justify-content:space-between;align-items:flex-start;gap:12px;margin:4px 0 14px}
#spt-col h1{font-size:clamp(1.35rem,3.2vw,2rem);margin:0;letter-spacing:-.02em}
#spt-col .hd p{margin:4px 0 0;color:var(--mut);font-size:.95rem}
#spt-col .badge{background:linear-gradient(135deg,#1e3a8a,#2563eb);color:#fff;font-weight:700;font-size:.78rem;padding:6px 12px;border-radius:999px;white-space:nowrap}
#spt-col .hdr{display:flex;align-items:center;gap:10px}
#spt-col .lang{display:inline-flex;background:#e2e8f0;border-radius:999px;padding:3px;gap:2px}
#spt-col .lang button{font:inherit;font-size:.78rem;font-weight:700;border:0;background:transparent;color:#475569;padding:5px 11px;border-radius:999px;cursor:pointer;transition:.15s}
#spt-col .lang button.on{background:#fff;color:#1e3a8a;box-shadow:0 1px 3px rgba(15,23,42,.18)}

#spt-col .wrap{max-width:1120px;margin:0 auto;padding:0 20px}
#spt-col a{color:inherit;text-decoration:none}
/* Navegación */
#spt-col .nav{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.88);backdrop-filter:saturate(1.6) blur(10px);-webkit-backdrop-filter:saturate(1.6) blur(10px);border-bottom:1px solid var(--line)}
#spt-col .nav .wrap{display:flex;align-items:center;justify-content:space-between;gap:14px;height:64px}
#spt-col .brand{display:flex;align-items:center;gap:9px;font-weight:800;font-size:1.15rem;letter-spacing:-.02em;color:#1e3a8a;white-space:nowrap}
#spt-col .brand b{color:#f59e0b}
#spt-col .links{display:flex;gap:4px;align-items:center}
#spt-col .links a{font-size:.92rem;font-weight:600;color:#334155;padding:8px 12px;border-radius:8px;transition:.15s}
#spt-col .links a:hover{background:#eff6ff;color:#1d4ed8}
#spt-col .navr{display:flex;align-items:center;gap:10px}
#spt-col .home{font-size:.84rem;font-weight:700;background:#0f172a;color:#fff !important;padding:8px 14px;border-radius:999px;white-space:nowrap}
#spt-col .home:hover{background:#1e293b}
/* Portada */
#spt-col .hero{position:relative;overflow:hidden;color:#e2e8f0;background:radial-gradient(1200px 500px at 85% -10%,rgba(37,99,235,.45),transparent 60%),radial-gradient(800px 400px at 0% 110%,rgba(16,185,129,.25),transparent 60%),linear-gradient(160deg,#0b1220,#13203f 60%,#0b1220)}
#spt-col .hero::before{content:"";position:absolute;inset:0;background-image:linear-gradient(rgba(148,163,184,.07) 1px,transparent 1px),linear-gradient(90deg,rgba(148,163,184,.07) 1px,transparent 1px);background-size:32px 32px;mask-image:linear-gradient(to bottom,#000,transparent 95%);-webkit-mask-image:linear-gradient(to bottom,#000,transparent 95%)}
#spt-col .hero .wrap{position:relative;display:grid;grid-template-columns:1.15fr .85fr;gap:40px;align-items:center;padding-top:64px;padding-bottom:72px}
#spt-col .tag{display:inline-block;font-size:.78rem;font-weight:700;letter-spacing:.08em;text-transform:uppercase;color:#93c5fd;background:rgba(37,99,235,.18);border:1px solid rgba(147,197,253,.3);padding:6px 12px;border-radius:999px}
#spt-col .hero h1{color:#fff;font-size:clamp(2rem,4.6vw,3.2rem);line-height:1.08;margin:16px 0 14px;letter-spacing:-.03em}
#spt-col .hero .lead{font-size:1.08rem;color:#cbd5e1;max-width:560px;margin:0}
#spt-col .hero .lead b{color:#fff}
#spt-col .cta{display:flex;flex-wrap:wrap;gap:12px;margin:26px 0 22px}
#spt-col .cta a{font-weight:700;padding:12px 22px;border-radius:12px;font-size:.98rem;transition:.15s}
#spt-col .cta .a1{background:#2563eb;color:#fff;box-shadow:0 8px 24px rgba(37,99,235,.45)}
#spt-col .cta .a1:hover{background:#1d4ed8;transform:translateY(-1px)}
#spt-col .cta .a2{border:1px solid rgba(203,213,225,.35);color:#e2e8f0}
#spt-col .cta .a2:hover{background:rgba(255,255,255,.08)}
#spt-col .chips{display:flex;flex-wrap:wrap;gap:8px}
#spt-col .chips span{font-size:.82rem;color:#cbd5e1;background:rgba(255,255,255,.06);border:1px solid rgba(255,255,255,.1);padding:6px 11px;border-radius:999px}
#spt-col .demo{background:rgba(15,23,42,.6);border:1px solid rgba(148,163,184,.2);border-radius:18px;padding:22px;box-shadow:0 30px 60px rgba(0,0,0,.35)}
#spt-col .demo svg{width:100%;height:auto;display:block}
#spt-col .demo .eq{display:flex;justify-content:space-around;flex-wrap:wrap;gap:8px;margin-top:14px;font-family:"Cambria Math","Times New Roman",serif;font-size:1.1rem;color:#e2e8f0}
#spt-col .demo .eq span{background:rgba(255,255,255,.06);padding:6px 12px;border-radius:8px}
@keyframes sptA{0%,8%{transform:translateX(0)}46%,100%{transform:translateX(50px)}}
@keyframes sptB{0%,46%{transform:translateX(0)}84%,100%{transform:translateX(150px)}}
@keyframes sptF{0%,44%{opacity:0}46%{opacity:1}56%,100%{opacity:0}}
#spt-col .ca{animation:sptA 3.2s cubic-bezier(.4,0,.6,1) infinite}
#spt-col .cb{animation:sptB 3.2s cubic-bezier(.4,0,.6,1) infinite}
#spt-col .fl{animation:sptF 3.2s linear infinite}
@media (prefers-reduced-motion:reduce){#spt-col .ca,#spt-col .cb,#spt-col .fl{animation:none}}
/* Secciones */
#spt-col .sec{padding:64px 0;scroll-margin-top:64px}
#spt-col .sec.alt{background:#fff;border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
#spt-col .sh{text-align:center;max-width:720px;margin:0 auto 32px}
#spt-col .sh .tag{color:#1d4ed8;background:#eff6ff;border-color:#bfdbfe}
#spt-col .sh h2{font-size:clamp(1.6rem,3.4vw,2.3rem);margin:12px 0 8px;letter-spacing:-.025em}
#spt-col .sh p{color:var(--mut);margin:0;font-size:1.02rem}
#spt-col .grid4{display:grid;grid-template-columns:repeat(4,1fr);gap:16px}
#spt-col .grid2{display:grid;grid-template-columns:1fr 1fr;gap:16px}
#spt-col .info{padding:22px;transition:.2s}
#spt-col .info:hover{transform:translateY(-3px);box-shadow:0 14px 34px rgba(15,23,42,.1)}
#spt-col .ico{width:44px;height:44px;border-radius:12px;display:grid;place-items:center;font-size:1.3rem;margin-bottom:12px}
#spt-col .info h3{margin:0 0 8px;font-size:1.06rem}
#spt-col .info p{margin:0;color:#475569;font-size:.93rem}
#spt-col .act{padding:22px;display:flex;flex-direction:column;gap:10px}
#spt-col .act .n{font-size:.78rem;font-weight:800;color:#2563eb;letter-spacing:.08em}
#spt-col .act h3{margin:0;font-size:1.1rem}
#spt-col .act p{margin:0;color:#475569;font-size:.95rem;flex:1}
#spt-col .act .btn{align-self:flex-start}
#spt-col details{background:#fff;border:1px solid var(--line);border-radius:12px;padding:0 18px;margin-bottom:10px}
#spt-col summary{cursor:pointer;font-weight:700;padding:16px 0;list-style:none;display:flex;justify-content:space-between;gap:12px}
#spt-col summary::-webkit-details-marker{display:none}
#spt-col summary::after{content:"+";font-size:1.3rem;color:#2563eb;line-height:1}
#spt-col details[open] summary::after{content:"−"}
#spt-col details p{margin:0 0 16px;color:#475569}
#spt-col .faq{max-width:820px;margin:0 auto}
/* Pie */
#spt-col .ft{background:#0b1220;color:#94a3b8;padding:44px 0 26px}
#spt-col .ft .wrap{display:grid;grid-template-columns:1.4fr 1fr;gap:30px}
#spt-col .ft .brand{color:#fff;margin-bottom:10px}
#spt-col .ft p{margin:0;font-size:.92rem;max-width:420px}
#spt-col .ft .fl2{display:flex;flex-wrap:wrap;gap:8px 20px;align-content:flex-start;justify-content:flex-end}
#spt-col .ft .fl2 a{color:#cbd5e1;font-size:.92rem}
#spt-col .ft .fl2 a:hover{color:#fff}
#spt-col .ft .copy{grid-column:1/-1;border-top:1px solid #1e293b;padding-top:18px;font-size:.82rem;text-align:center}
#spt-col .simhd{display:none}
@media (max-width:900px){
  #spt-col .hero .wrap{grid-template-columns:1fr;padding-top:44px;padding-bottom:52px}
  #spt-col .grid4{grid-template-columns:1fr 1fr}
  #spt-col .links{display:none}
}
@media (max-width:640px){
  #spt-col .wrap{padding:0 12px}
  #spt-col .grid4,#spt-col .grid2,#spt-col .ft .wrap{grid-template-columns:1fr}
  #spt-col .ft .fl2{justify-content:flex-start}
  #spt-col .home{display:none}
  #spt-col .sec{padding:44px 0}
  #spt-col th,#spt-col td{padding:7px 6px}
  #spt-col .theory{padding:14px 12px}
}
#spt-col .stage{padding:10px;overflow:hidden}
#spt-col #cv-sim{width:100%;display:block;border-radius:10px}
#spt-col .bar{display:flex;flex-wrap:wrap;justify-content:space-between;align-items:center;gap:10px;padding:10px 4px 2px}
#spt-col .btns,#spt-col .opts{display:flex;flex-wrap:wrap;gap:8px;align-items:center}
#spt-col .btn{font:inherit;font-weight:700;font-size:.9rem;border:1px solid var(--line);background:#fff;color:var(--ink);padding:9px 16px;border-radius:10px;cursor:pointer;transition:.15s}
#spt-col .btn:hover{background:#f8fafc;border-color:#cbd5e1}
#spt-col .btn.pri{background:var(--acc);border-color:var(--acc);color:#fff;min-width:130px}
#spt-col .btn.pri:hover{background:#1d4ed8}
#spt-col .tg,#spt-col .sel{display:inline-flex;align-items:center;gap:6px;font-size:.88rem;color:#334155;background:#f8fafc;border:1px solid var(--line);padding:6px 10px;border-radius:999px;cursor:pointer;user-select:none}
#spt-col .tg input{accent-color:var(--acc)}
#spt-col select{font:inherit;font-size:.88rem;border:1px solid var(--line);border-radius:8px;padding:4px 6px;background:#fff;color:var(--ink)}
#spt-col .tiles{display:grid;grid-template-columns:repeat(4,1fr);gap:12px;margin:14px 0}
#spt-col .tile{padding:12px 14px}
#spt-col .tile .k{font-size:.78rem;color:var(--mut);text-transform:uppercase;letter-spacing:.05em;font-weight:600}
#spt-col .tile .v{font-family:ui-monospace,"SFMono-Regular",Consolas,monospace;font-size:1.35rem;font-weight:700;color:var(--tot);margin-top:2px}
#spt-col .tile .s{font-size:.8rem;color:var(--mut)}
#spt-col .ebar{padding:12px 14px;margin-bottom:14px}
#spt-col .ebar .t{font-size:.85rem;font-weight:600;margin-bottom:8px;display:flex;justify-content:space-between;flex-wrap:wrap;gap:6px}
#spt-col .track{display:flex;height:18px;border-radius:9px;overflow:hidden;background:#e2e8f0}
#spt-col .track div{height:100%;transition:width .12s linear}
#spt-col .lg{display:flex;flex-wrap:wrap;gap:14px;margin-top:8px;font-size:.8rem;color:#475569}
#spt-col .lg i{display:inline-block;width:10px;height:10px;border-radius:3px;margin-right:5px;vertical-align:-1px}
#spt-col .ctrl{display:grid;grid-template-columns:1fr 1fr 1.15fr;gap:12px;margin-bottom:14px}
#spt-col .cc{padding:14px 16px}
#spt-col .cc.c1{border-left:5px solid var(--c1)}
#spt-col .cc.c2{border-left:5px solid var(--c2)}
#spt-col .cc.col{border-left:5px solid var(--acc)}
#spt-col h3{margin:0 0 10px;font-size:1.02rem}
#spt-col .row{display:grid;grid-template-columns:96px 1fr 76px;gap:10px;align-items:center;margin:10px 0}
#spt-col .lab{font-size:.86rem;font-weight:600;display:flex;flex-direction:column}
#spt-col .lab .u{font-weight:400;color:var(--mut);font-size:.76rem}
#spt-col input[type=range]{width:100%;accent-color:var(--acc)}
#spt-col .c1 input[type=range]{accent-color:var(--c1)}
#spt-col .c2 input[type=range]{accent-color:var(--c2)}
#spt-col input[type=number]{width:100%;font:inherit;font-family:ui-monospace,Consolas,monospace;font-size:.9rem;border:1px solid var(--line);border-radius:8px;padding:5px 6px;text-align:right}
#spt-col .seg{display:flex;gap:6px;flex-wrap:wrap;margin:6px 0 10px}
#spt-col .seg button{flex:1;font:inherit;font-size:.8rem;font-weight:600;border:1px solid var(--line);background:#f8fafc;padding:7px 6px;border-radius:8px;cursor:pointer;color:#334155;min-width:90px}
#spt-col .seg button.on{background:var(--acc);color:#fff;border-color:var(--acc)}
#spt-col .full{width:100%}
#spt-col .tbl{padding:6px 14px 10px;margin-bottom:14px;overflow-x:auto}
#spt-col table{width:100%;border-collapse:collapse;font-size:.9rem}
#spt-col th{text-align:right;font-size:.76rem;text-transform:uppercase;letter-spacing:.04em;color:var(--mut);font-weight:600;padding:8px 10px;border-bottom:1px solid var(--line)}
#spt-col th:first-child,#spt-col td:first-child{text-align:left}
#spt-col td{padding:7px 10px;border-bottom:1px solid #f1f5f9;text-align:right;font-family:ui-monospace,Consolas,monospace}
#spt-col td:first-child{font-family:inherit;font-weight:700}
#spt-col tr:last-child td{border-bottom:none}
#spt-col .dot{display:inline-block;width:10px;height:10px;border-radius:50%;margin-right:6px}
#spt-col .charts{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin-bottom:14px}
#spt-col .ch{padding:10px 12px}
#spt-col .ch h4{margin:2px 0 6px;font-size:.92rem}
#spt-col .ch canvas{width:100%;display:block}
#spt-col .theory{padding:16px 18px;margin-bottom:14px}
#spt-col .fx{display:grid;grid-template-columns:1fr 1fr;gap:10px 22px;background:#f8fafc;border:1px solid var(--line);border-radius:10px;padding:14px;margin:6px 0 14px;font-family:"Cambria Math","Times New Roman",serif;font-size:1.05rem}
#spt-col .fx div{display:flex;align-items:center;gap:6px;flex-wrap:wrap}
#spt-col .fr{display:inline-flex;flex-direction:column;align-items:center;vertical-align:middle;margin:0 3px}
#spt-col .fr>span:first-child{padding:0 4px 2px}
#spt-col .fr>span:last-child{border-top:1.4px solid currentColor;padding:2px 4px 0;width:100%;text-align:center}
#spt-col .note{font-size:.88rem;color:#334155;background:#eff6ff;border:1px solid #bfdbfe;border-radius:10px;padding:10px 12px;margin-top:12px}
#spt-col .note.warn{background:#fffbeb;border-color:#fde68a}
#spt-col .ok{color:#059669;font-weight:700}
#spt-col .foot{font-size:.8rem;color:var(--mut);text-align:center;margin:4px 0 8px}
#spt-col .acts{display:flex;justify-content:flex-end;margin-top:12px}
@media (max-width:900px){
  #spt-col .ctrl{grid-template-columns:1fr 1fr}
  #spt-col .ctrl .col{grid-column:1/-1}
  #spt-col .tiles{grid-template-columns:1fr 1fr}
}
@media (max-width:640px){
  #spt-col .ctrl,#spt-col .charts,#spt-col .fx{grid-template-columns:1fr}
  #spt-col .row{grid-template-columns:78px 1fr 68px}
  #spt-col .tile .v{font-size:1.1rem}
  #spt-col .badge{display:none}
}