:root{--green:#304c39;--green2:#44644d;--ink:#1f2522;--muted:#657069;--paper:#f5f7f5;--card:#fff;--line:#dbe2dc;--soft:#eaf0eb;--danger:#9c2f2f;--shadow:0 18px 45px rgba(30,52,38,.12)}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;font-family:Inter,Segoe UI,Arial,sans-serif;color:var(--ink);background:linear-gradient(180deg,#eef3ef 0,#f8faf8 42%,#eef3ef 100%);min-height:100vh}
button,input,select{font:inherit}.topbar{position:sticky;top:0;z-index:10;height:82px;padding:10px clamp(16px,4vw,52px);display:flex;align-items:center;justify-content:space-between;background:rgba(255,255,255,.92);backdrop-filter:blur(14px);border-bottom:1px solid var(--line)}
.brand{border:0;background:transparent;padding:0;cursor:pointer}.brand img{display:block;width:145px;height:58px;object-fit:contain}.home-btn,.back{border:0;background:transparent;color:var(--green);font-weight:750;cursor:pointer}.home-btn{padding:10px 14px;border-radius:10px}.home-btn:hover,.back:hover{background:var(--soft)}
.app-shell{width:min(1120px,calc(100% - 32px));margin:0 auto;padding:42px 0 56px}.view{display:none}.view.active{display:block;animation:fade .28s ease}@keyframes fade{from{opacity:0;transform:translateY(6px)}to{opacity:1;transform:none}}
.hero{text-align:center;max-width:780px;margin:16px auto 38px}.eyebrow{display:inline-block;color:var(--green2);font-size:.78rem;font-weight:850;letter-spacing:.13em;text-transform:uppercase}.hero h1,.section-heading h2{font-size:clamp(2rem,5vw,3.8rem);line-height:1.03;margin:10px 0 14px}.hero p,.section-heading p{color:var(--muted);font-size:clamp(1rem,2vw,1.18rem);line-height:1.65;margin:0}
.tool-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}.tool-card{text-align:left;min-height:260px;padding:24px;border:1px solid var(--line);border-radius:22px;background:var(--card);box-shadow:var(--shadow);cursor:pointer;transition:.2s transform,.2s border-color,.2s box-shadow;display:flex;flex-direction:column}.tool-card:hover{transform:translateY(-4px);border-color:#9eb1a2;box-shadow:0 23px 52px rgba(30,52,38,.16)}.tool-number{align-self:flex-end;color:#87938b;font-weight:800}.tool-icon{width:58px;height:58px;border-radius:16px;background:var(--green);color:#fff;display:grid;place-items:center;font-size:1.35rem;font-weight:900;margin:18px 0}.tool-card strong{font-size:1.22rem;margin-bottom:10px}.tool-card small{color:var(--muted);font-size:.96rem;line-height:1.5}
.section-heading{max-width:760px;margin:0 auto 24px}.back{padding:9px 0;margin-bottom:26px}.calculator-card{max-width:760px;margin:0 auto;background:var(--card);border:1px solid var(--line);border-radius:22px;padding:clamp(22px,4vw,36px);box-shadow:var(--shadow)}.field-grid{display:grid;grid-template-columns:1fr 1fr;gap:20px}label{display:block;font-weight:750;color:#354039}label em{font-weight:500;color:var(--muted);font-size:.9rem}.input-wrap{display:flex;align-items:center;margin-top:8px;border:1px solid #cdd7cf;border-radius:12px;overflow:hidden;background:#fff}.input-wrap:focus-within{border-color:var(--green2);box-shadow:0 0 0 3px rgba(68,100,77,.12)}input,select{width:100%;border:1px solid #cdd7cf;border-radius:12px;padding:14px 15px;background:#fff;color:var(--ink);outline:none}input{border:0;border-radius:0}.input-wrap b{padding:0 14px;color:var(--muted);font-size:.9rem;border-left:1px solid var(--line)}select{margin-top:8px}.actions{display:flex;gap:12px;margin-top:24px}.primary,.secondary{border:0;border-radius:12px;padding:13px 20px;font-weight:800;cursor:pointer}.primary{background:var(--green);color:#fff}.primary:hover{background:#243b2d}.secondary{background:var(--soft);color:var(--green)}.note,.warning{font-size:.86rem;line-height:1.5;color:var(--muted);margin:18px 0 0}.warning{padding:13px 14px;border-left:4px solid #c8a14a;background:#fff9eb;border-radius:8px}.result{margin-top:24px;padding:20px;border-radius:16px;background:linear-gradient(135deg,#eff5f0,#e4eee6);border:1px solid #cbd9ce}.result.error{background:#fff1f1;border-color:#e6b8b8;color:var(--danger)}.result h3{margin:0 0 8px;font-size:1rem;text-transform:uppercase;letter-spacing:.08em;color:var(--green2)}.result .big{font-size:clamp(2.1rem,6vw,3.4rem);font-weight:900;color:var(--green);line-height:1}.result p{margin:10px 0 0;line-height:1.55}.result dl{display:grid;grid-template-columns:1fr auto;gap:10px 18px;margin:12px 0 0}.result dt{color:var(--muted)}.result dd{margin:0;font-weight:800;text-align:right}footer{text-align:center;color:var(--muted);padding:0 20px 30px;font-size:.9rem}
@media(max-width:820px){.tool-grid{grid-template-columns:1fr}.tool-card{min-height:210px}.field-grid{grid-template-columns:1fr}.app-shell{padding-top:26px}}
@media(max-width:520px){.topbar{height:70px;padding:8px 14px}.brand img{width:120px;height:48px}.app-shell{width:min(100% - 22px,1120px)}.hero{text-align:left}.hero h1,.section-heading h2{font-size:2.25rem}.calculator-card{border-radius:17px;padding:20px}.actions{flex-direction:column}.primary,.secondary{width:100%}.result dl{grid-template-columns:1fr}.result dd{text-align:left;margin-bottom:5px}}
.wide-heading{max-width:1120px}.equiv-layout{display:grid;grid-template-columns:250px 1fr;gap:22px;align-items:start}.equiv-menu{position:sticky;top:104px;display:flex;flex-direction:column;gap:10px}.equiv-tab{border:1px solid var(--line);background:#fff;border-radius:14px;padding:16px;text-align:left;cursor:pointer;color:var(--ink)}.equiv-tab strong,.equiv-tab small{display:block}.equiv-tab small{margin-top:5px;color:var(--muted)}.equiv-tab.active{background:linear-gradient(135deg,#e7f0e8,#f6f9f6);border-color:#b9ccbd}.mini-warning{margin-top:14px;padding:16px;border:1px solid var(--line);border-radius:14px;background:#f8faf8}.mini-warning strong{color:var(--green);text-transform:uppercase;letter-spacing:.08em;font-size:.78rem}.mini-warning p{font-size:.86rem;line-height:1.55;color:var(--muted);margin:8px 0 0}.equiv-main{min-width:0}.equiv-panel{display:none;background:#fff;border:1px solid var(--line);border-radius:22px;padding:clamp(20px,3vw,30px);box-shadow:var(--shadow)}.equiv-panel.active{display:block}.comparison-controls{display:grid;grid-template-columns:1fr 1fr;gap:16px}.equiv-summary{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;margin:22px 0}.equiv-summary>div{border:1px solid var(--line);border-radius:14px;padding:15px;background:var(--paper)}.equiv-summary span,.equiv-summary strong{display:block}.equiv-summary span{font-size:.78rem;color:var(--muted);margin-bottom:7px}.equiv-summary strong{color:var(--green);font-size:1.05rem}.viscosity-table-wrap{overflow:auto;border:1px solid var(--line);border-radius:14px}.viscosity-table{width:100%;border-collapse:collapse;min-width:720px}.viscosity-table th,.viscosity-table td{padding:12px 14px;border-bottom:1px solid var(--line);text-align:center}.viscosity-table th{background:#f3f6f3;color:var(--green);font-size:.82rem;text-transform:uppercase;letter-spacing:.05em}.viscosity-table tr:last-child td{border-bottom:0}.viscosity-table tr.selected td{background:#e8f3ea;font-weight:800}.viscosity-table tr.selected td:first-child{box-shadow:inset 4px 0 var(--green)}.converter-card{max-width:760px}.guide-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px}.guide-grid article{border:1px solid var(--line);border-radius:16px;padding:18px;background:var(--paper)}.guide-grid h3{margin:0 0 8px;color:var(--green)}.guide-grid p{margin:0;color:var(--muted);line-height:1.6}
@media(max-width:900px){.equiv-layout{grid-template-columns:1fr}.equiv-menu{position:static;display:grid;grid-template-columns:repeat(3,1fr)}.mini-warning{grid-column:1/-1}.equiv-summary{grid-template-columns:1fr}.comparison-controls{grid-template-columns:1fr}}
@media(max-width:620px){.equiv-menu{grid-template-columns:1fr}.guide-grid{grid-template-columns:1fr}.equiv-panel{padding:16px}}


/* Mejoras v4 */
.emphasized-input{
  width:100%;
  min-height:54px;
  padding:14px 16px;
  border:2px solid var(--green);
  border-radius:12px;
  background:#fff;
  box-shadow:0 0 0 4px rgba(48,76,57,.08);
  font-size:1.08rem;
  font-weight:700;
  color:var(--ink);
}
.emphasized-input:focus{
  outline:none;
  border-color:var(--green2);
  box-shadow:0 0 0 5px rgba(48,76,57,.16);
}
.chart-actions{display:flex;justify-content:flex-end;margin:14px 0 10px}
.chart-toggle{white-space:normal}
.equivalence-chart{
  margin:0 0 18px;
  padding:14px;
  border:1px solid var(--line);
  border-radius:16px;
  background:var(--soft);
}
.equivalence-chart img{display:block;width:100%;height:auto;border-radius:12px;background:#fff}
.equivalence-chart p{margin:10px 2px 0;color:var(--muted);font-size:.9rem}
@media(max-width:620px){.chart-actions{justify-content:stretch}.chart-toggle{width:100%}}
/* v5: gráfico comparativo independiente */
.chart-header{display:flex;align-items:flex-end;justify-content:space-between;gap:18px;margin-bottom:4px}
.chart-header h3{font-size:1.35rem;margin:2px 0 0;color:var(--ink)}
.chart-selected{font-weight:800;color:var(--green);background:#fff;border:1px solid var(--line);border-radius:999px;padding:8px 14px;white-space:nowrap}
.chart-intro{margin:6px 0 14px!important}
.comparison-chart-wrap{overflow-x:auto;background:#fff;border:1px solid var(--line);border-radius:14px;padding:10px}
.comparison-chart{min-width:720px}
.chart-row{display:grid;grid-template-columns:1.15fr 1fr .9fr 1.2fr 1.25fr;gap:8px;align-items:center;padding:5px 8px;border-bottom:1px dashed #dbe2dc;transition:.18s ease}
.chart-row:last-child{border-bottom:0}
.chart-row.chart-head{font-size:.76rem;text-transform:uppercase;letter-spacing:.06em;font-weight:800;color:var(--muted);border-bottom:1px solid var(--line);padding:8px}
.chart-row.selected{background:#edf5ef;outline:2px solid var(--green2);border-radius:10px;border-bottom-color:transparent;transform:scale(1.005)}
.chart-cell{display:flex;justify-content:center;align-items:center;min-height:29px;text-align:center;font-weight:700}
.chart-cst{justify-content:flex-start;color:var(--muted);font-weight:600}
.chart-pill{width:min(100%,110px);padding:5px 8px;border-radius:5px;color:#fff;box-shadow:inset 0 -1px 0 rgba(0,0,0,.16)}
.chart-pill.empty{background:transparent!important;box-shadow:none;color:#a5ada7}
.chart-pill.iso{background:#078d8e}.chart-pill.agma{background:#bd2338}.chart-pill.motor{background:#37934d}.chart-pill.gear{background:#0759b2}
.chart-legend{display:flex;flex-wrap:wrap;gap:16px;margin:12px 4px 0;font-size:.82rem;color:var(--muted)}
.chart-legend span{display:flex;align-items:center;gap:6px}.chart-legend i{width:12px;height:12px;border-radius:2px;display:inline-block}.iso-dot{background:#078d8e}.agma-dot{background:#bd2338}.motor-dot{background:#37934d}.gear-dot{background:#0759b2}
@media(max-width:620px){.chart-header{align-items:flex-start;flex-direction:column}.chart-selected{font-size:.9rem}.equivalence-chart{padding:10px}.comparison-chart-wrap{padding:6px}}


/* v6: recursos, Tips y Ayudas y asesoramiento */
.resource-heading{margin:46px 0 16px}.resource-heading h2{margin:5px 0 0;font-size:1.65rem}.resource-grid{display:grid;grid-template-columns:1fr 1fr;gap:18px}.resource-card{appearance:none;text-decoration:none;text-align:left;border:1px solid var(--line);background:#fff;border-radius:18px;padding:20px;color:var(--ink);cursor:pointer;display:grid;grid-template-columns:auto 1fr;column-gap:14px;box-shadow:var(--shadow)}.resource-card:hover{border-color:#9eb1a2;transform:translateY(-2px)}.resource-icon{grid-row:1/3;width:46px;height:46px;border-radius:13px;background:var(--soft);display:grid;place-items:center;font-size:1.35rem}.resource-card strong{font-size:1.08rem}.resource-card small{color:var(--muted);margin-top:5px;line-height:1.45}.tips-card{background:#fff;border:1px solid var(--line);border-radius:22px;padding:clamp(18px,3vw,28px);box-shadow:var(--shadow)}.tips-tabs{display:grid;grid-template-columns:repeat(4,1fr);gap:8px;padding:6px;border:1px solid var(--line);border-radius:16px;background:#fafbfa}.tips-tab{border:0;background:transparent;border-radius:12px;padding:13px 10px;font-weight:800;color:#3c4540;cursor:pointer}.tips-tab.active{background:var(--green);color:#fff}.tip-panel{display:none;padding-top:24px}.tip-panel.active{display:block}.tip-panel h3{font-size:1.55rem;margin:0 0 7px}.tip-lead{color:var(--muted);margin:0 0 18px;line-height:1.55}.oil-guide{display:block;width:100%;height:auto;border:1px solid var(--line);border-radius:16px}.tip-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:14px}.tip-grid article{border:1px solid var(--line);border-radius:15px;padding:18px;background:var(--paper)}.tip-grid b{color:var(--green);font-size:1.02rem}.tip-grid p{color:var(--muted);line-height:1.55;margin:8px 0 0}.safety-note{padding:14px 16px;background:#fff8e9;border-left:4px solid #d69b28;border-radius:10px;line-height:1.5}.tips-advice{margin-top:20px;border-radius:16px;padding:18px;background:linear-gradient(135deg,#eaf2eb,#f8faf8);display:flex;align-items:center;justify-content:space-between;gap:20px}.tips-advice strong,.tips-advice span{display:block}.tips-advice span{color:var(--muted);margin-top:4px}.link-button{text-decoration:none;white-space:nowrap;display:inline-block}.result .advice-cta{margin-top:16px;padding-top:14px;border-top:1px solid #cbd9ce}.result .advice-cta a{color:var(--green);font-weight:850;text-decoration:none}
@media(max-width:760px){.resource-grid,.tip-grid{grid-template-columns:1fr}.tips-tabs{grid-template-columns:1fr 1fr}.tips-advice{align-items:stretch;flex-direction:column}.link-button{text-align:center}.resource-heading{margin-top:34px}}
@media(max-width:460px){.tips-tabs{grid-template-columns:1fr}.tips-tab{text-align:left}}

/* PWA v1.0 */
.top-actions{display:flex;align-items:center;gap:.65rem}
.install-btn{border:0;border-radius:999px;padding:.7rem 1rem;font-weight:800;cursor:pointer;background:#e8f1eb;color:#304c39;box-shadow:inset 0 0 0 1px rgba(48,76,57,.18)}
.install-btn:hover{background:#dceadf}
@media(max-width:640px){.install-btn{padding:.62rem .78rem;font-size:.85rem}.top-actions{gap:.4rem}}
\n\n/* Splash de prueba: portada 2 segundos al abrir la APP */
body.splash-active { overflow: hidden; }
.splash-screen {
  position: fixed;
  inset: 0;
  z-index: 99999;
  display: flex;
  align-items: center;
  justify-content: center;
  background: #06100b;
  opacity: 1;
  visibility: visible;
  transition: opacity .45s ease, visibility .45s ease;
}
.splash-screen img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
}
.splash-screen.splash-hide { opacity: 0; visibility: hidden; pointer-events: none; }
@media (max-width: 700px) {
  .splash-screen { background: #06100b; }
  .splash-screen img { object-fit: contain; }
}


/* Prueba: aviso inicial de uso */
body.notice-active{overflow:hidden}
.use-notice{position:fixed;inset:0;z-index:99998;background:rgba(5,15,10,.72);backdrop-filter:blur(7px);padding:20px;display:grid;place-items:center}
.use-notice[hidden]{display:none}
.use-notice-card{width:min(720px,100%);max-height:calc(100vh - 40px);overflow:auto;background:#fff;border-radius:22px;padding:clamp(22px,4vw,34px);box-shadow:0 24px 80px rgba(0,0,0,.28);border-top:5px solid var(--green)}
.notice-kicker{display:block;color:var(--green);font-size:.78rem;font-weight:850;letter-spacing:.08em;text-transform:uppercase;margin-bottom:8px}
.use-notice-card h2{margin:0 0 16px;font-size:clamp(1.55rem,4vw,2rem);color:var(--ink)}
.use-notice-card p{color:#4e5952;line-height:1.58;margin:0 0 13px}
.use-notice-card a{color:var(--green);font-weight:800}
.notice-accept{width:100%;margin:8px 0 10px;padding:14px 18px;font-size:1rem}
.use-notice-card small{display:block;color:var(--muted);line-height:1.45;text-align:center}
.footer-notice-link{border:0;background:transparent;color:inherit;text-decoration:underline;cursor:pointer;font:inherit;padding:0}
@media(max-width:560px){.use-notice{padding:10px}.use-notice-card{max-height:calc(100vh - 20px);border-radius:17px;padding:20px}.use-notice-card p{font-size:.92rem}}