/* ===================================================================
   TRN · Ingeniería y Construcción — Sistema de diseño
   Azul Marino #14294D · Grafito #14181C · Gris Acero #5B6470
   Plata #C9CED5 · Blanco #FFFFFF
=================================================================== */
:root{
  --navy:#14294D;
  --navy-900:#0F1F3A;
  --graphite:#14181C;
  --steel:#5B6470;
  --steel-light:#8A929C;
  --silver:#C9CED5;
  --mist:#F5F6F8;
  --line:#E4E7EC;
  --white:#FFFFFF;

  --wa:#25D366;

  --font:'Montserrat',-apple-system,BlinkMacSystemFont,'Segoe UI',Arial,sans-serif;
  --serif:'Cinzel',Georgia,'Times New Roman',serif;

  --container:1200px;
  --radius:4px;
  --ease:cubic-bezier(.22,.61,.36,1);
  --shadow-sm:0 2px 10px rgba(20,24,28,.06);
  --shadow-md:0 14px 40px rgba(20,41,77,.12);
  --shadow-lg:0 30px 70px rgba(15,31,58,.22);
}

*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  font-family:var(--font);
  color:var(--graphite);
  background:var(--white);
  line-height:1.6;
  font-size:16px;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
img{max-width:100%;display:block}
a{color:inherit;text-decoration:none}
ul{list-style:none}

.container{width:100%;max-width:var(--container);margin:0 auto;padding:0 22px}

/* ---------- Typography ---------- */
h1,h2,h3,h4{line-height:1.14;font-weight:700;letter-spacing:-.01em;color:var(--graphite)}
h2{font-size:clamp(1.7rem,4.4vw,2.75rem);font-weight:700}
h3{font-size:1.2rem;font-weight:600}
.lead{font-size:1.075rem;color:var(--steel)}
.eyebrow{
  font-size:.72rem;font-weight:600;letter-spacing:.22em;text-transform:uppercase;
  color:var(--navy);margin-bottom:14px;display:flex;align-items:center;gap:10px;
}
.eyebrow::before{content:"";width:26px;height:2px;background:var(--silver)}
.eyebrow-light{color:var(--silver)}
.eyebrow-light::before{background:rgba(201,206,213,.5)}

.section{padding:clamp(64px,9vw,120px) 0}
section[id]{scroll-margin-top:78px}
.section-head{max-width:640px;margin:0 auto clamp(38px,5vw,60px);text-align:center}
.section-head .eyebrow{justify-content:center}
.section-intro{color:var(--steel);margin-top:14px;font-size:1.05rem}

/* ---------- Buttons ---------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:9px;
  font-family:var(--font);font-weight:600;font-size:.92rem;letter-spacing:.02em;
  padding:15px 30px;border-radius:var(--radius);border:1.5px solid transparent;
  cursor:pointer;transition:.28s var(--ease);white-space:nowrap;
}
.btn-sm{padding:11px 22px;font-size:.85rem}
.btn-block{width:100%}
.btn-primary{background:var(--navy);color:#fff;border-color:var(--navy)}
.btn-primary:hover{background:var(--navy-900);transform:translateY(-2px);box-shadow:var(--shadow-md)}
.btn-ghost{background:transparent;color:#fff;border-color:rgba(255,255,255,.5)}
.btn-ghost:hover{background:#fff;color:var(--navy);border-color:#fff}
.btn-white{background:#fff;color:var(--navy);border-color:#fff}
.btn-white:hover{transform:translateY(-2px);box-shadow:var(--shadow-lg)}
.btn-wa{background:var(--wa);border-color:var(--wa)}
.btn-wa:hover{background:#1eb457;border-color:#1eb457}

/* ---------- Header ---------- */
.site-header{
  position:fixed;top:0;left:0;right:0;z-index:100;
  padding:18px 0;transition:.35s var(--ease);
}
.site-header.scrolled{background:var(--navy);padding:11px 0;box-shadow:0 8px 30px rgba(15,31,58,.25)}
.header-inner{display:flex;align-items:center;justify-content:space-between;gap:20px}
.brand-logo{height:44px;width:auto;transition:.35s var(--ease)}
.scrolled .brand-logo{height:38px}
.nav{display:flex;align-items:center;gap:30px}
.nav a{font-size:.85rem;font-weight:500;color:rgba(255,255,255,.88);letter-spacing:.02em;position:relative;padding:4px 0}
.nav a::after{content:"";position:absolute;left:0;bottom:-2px;width:0;height:2px;background:var(--silver);transition:.3s var(--ease)}
.nav a:hover{color:#fff}
.nav a:hover::after{width:100%}
.nav-cta-mobile{display:none}
.header-actions{display:flex;align-items:center;gap:14px}
.nav-toggle{display:none;flex-direction:column;gap:5px;background:none;border:0;cursor:pointer;padding:6px}
.nav-toggle span{width:26px;height:2px;background:#fff;transition:.3s var(--ease)}
.nav-toggle[aria-expanded="true"] span:nth-child(1){transform:translateY(7px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] span:nth-child(2){opacity:0}
.nav-toggle[aria-expanded="true"] span:nth-child(3){transform:translateY(-7px) rotate(-45deg)}

/* ---------- Hero ---------- */
.hero{position:relative;min-height:100svh;display:flex;align-items:center;color:#fff;overflow:hidden}
.hero-media{
  position:absolute;inset:0;background-size:cover;background-position:center;
  transform:scale(1.06);animation:heroZoom 14s var(--ease) forwards;
}
@keyframes heroZoom{to{transform:scale(1)}}
.hero-overlay{
  position:absolute;inset:0;
  background:
    linear-gradient(180deg,rgba(15,31,58,.72) 0%,rgba(15,31,58,.55) 40%,rgba(20,41,77,.86) 100%),
    linear-gradient(90deg,rgba(15,31,58,.55),transparent 70%);
}
.hero-content{position:relative;z-index:2;padding-top:90px;padding-bottom:60px;max-width:820px}
.hero-title{
  font-size:clamp(2.3rem,6.2vw,4.4rem);font-weight:800;color:#fff;letter-spacing:-.02em;
  margin-bottom:22px;
}
.hero-title span{color:var(--silver);font-weight:300}
.hero-sub{font-size:clamp(1rem,2vw,1.2rem);color:rgba(255,255,255,.9);max-width:600px;margin-bottom:34px}
.hero-actions{display:flex;flex-wrap:wrap;gap:14px;margin-bottom:44px}
.hero-trust{display:flex;flex-wrap:wrap;gap:14px 28px}
.hero-trust li{font-size:.85rem;font-weight:500;color:rgba(255,255,255,.85);display:flex;align-items:center;gap:9px}
.hero-trust li::before{content:"";width:7px;height:7px;background:var(--silver);transform:rotate(45deg)}
.hero-scroll{
  position:absolute;bottom:26px;left:50%;transform:translateX(-50%);z-index:2;
  color:rgba(255,255,255,.7);font-size:1.4rem;animation:bounce 2s infinite
}
@keyframes bounce{0%,100%{transform:translateX(-50%) translateY(0)}50%{transform:translateX(-50%) translateY(8px)}}

/* ---------- Pilares ---------- */
.pillars{background:var(--navy);color:#fff;padding:clamp(50px,7vw,74px) 0}
.pillars-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:0}
.pillar{padding:8px 30px;border-left:1px solid rgba(255,255,255,.12)}
.pillar:first-child{border-left:0;padding-left:0}
.pillar-icon{color:var(--silver);font-size:1.1rem;display:block;margin-bottom:16px}
.pillar h3{color:#fff;font-size:1.02rem;margin-bottom:10px;font-weight:600}
.pillar p{font-size:.9rem;color:rgba(255,255,255,.72);line-height:1.55}

/* ---------- Nosotros ---------- */
.nosotros{background:var(--white)}
.about-grid{display:grid;grid-template-columns:0.9fr 1.1fr;gap:clamp(36px,6vw,80px);align-items:center}
.about-media{position:relative}
.about-media img{width:100%;height:100%;min-height:420px;object-fit:cover;border-radius:var(--radius);box-shadow:var(--shadow-md)}
.about-badge{
  position:absolute;bottom:-24px;right:-14px;background:var(--navy);color:#fff;
  padding:22px 26px;border-radius:var(--radius);box-shadow:var(--shadow-lg);max-width:210px
}
.about-badge strong{font-family:var(--serif);font-size:1.7rem;letter-spacing:.06em;display:block;color:#fff}
.about-badge span{font-size:.78rem;color:var(--silver);letter-spacing:.04em}
.about-text h2{margin-bottom:20px}
.about-text .lead{margin-bottom:16px;color:var(--graphite)}
.about-text > p{margin-bottom:16px;color:var(--steel)}
.mv-grid{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin:30px 0}
.mv-card{background:var(--mist);border-radius:var(--radius);padding:24px;border-top:3px solid var(--navy)}
.mv-card h3{color:var(--navy);margin-bottom:10px}
.mv-card p{font-size:.9rem;color:var(--steel)}
.values-label{font-size:.72rem;font-weight:600;letter-spacing:.2em;text-transform:uppercase;color:var(--navy);display:block;margin-bottom:14px}
.values ul{display:flex;flex-wrap:wrap;gap:10px}
.values li{
  font-size:.82rem;font-weight:500;padding:7px 15px;background:#fff;border:1px solid var(--line);
  border-radius:40px;color:var(--steel)
}

/* ---------- Servicios ---------- */
.services{background:var(--mist)}
.services-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:26px}
.service-card{
  background:#fff;border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow-sm);
  transition:.35s var(--ease);display:flex;flex-direction:column
}
.service-card:hover{transform:translateY(-6px);box-shadow:var(--shadow-md)}
.service-media{aspect-ratio:4/3;overflow:hidden}
.service-media img{width:100%;height:100%;object-fit:cover;transition:.6s var(--ease)}
.service-card:hover .service-media img{transform:scale(1.07)}
.service-body{padding:28px 26px 30px;position:relative;flex:1;display:flex;flex-direction:column}
.service-num{font-family:var(--serif);font-size:.9rem;color:var(--silver);letter-spacing:.1em}
.service-body h3{font-size:1.35rem;margin:6px 0 16px;color:var(--navy)}
.service-body ul{margin-bottom:22px;flex:1}
.service-body li{font-size:.92rem;color:var(--steel);padding:7px 0 7px 20px;position:relative;border-bottom:1px solid var(--line)}
.service-body li:last-child{border-bottom:0}
.service-body li::before{content:"";position:absolute;left:0;top:14px;width:7px;height:7px;background:var(--navy);transform:rotate(45deg)}
.link-arrow{font-weight:600;font-size:.88rem;color:var(--navy);transition:.25s var(--ease)}
.link-arrow:hover{color:var(--steel);letter-spacing:.02em}

/* ---------- Por qué TRN ---------- */
.why{background:var(--navy);color:#fff;position:relative}
.why-grid{display:grid;grid-template-columns:1fr 1fr;gap:clamp(36px,6vw,72px);align-items:center}
.why-text h2{color:#fff;margin-bottom:20px}
.why-text .lead{color:rgba(255,255,255,.82);margin-bottom:30px}
.why-list{display:grid;grid-template-columns:1fr 1fr;gap:2px}
.why-list li{
  display:flex;align-items:center;gap:14px;padding:16px 6px;font-size:.92rem;font-weight:500;
  color:rgba(255,255,255,.9);border-bottom:1px solid rgba(255,255,255,.1)
}
.why-list li span{font-family:var(--serif);font-size:.85rem;color:var(--silver);min-width:24px}

/* ---------- Proceso ---------- */
.process{background:var(--white)}
.process-steps{display:grid;grid-template-columns:repeat(4,1fr);gap:22px;counter-reset:step}
.process-steps li{position:relative;padding-top:28px}
.process-steps li::before{content:"";position:absolute;top:0;left:0;right:0;height:2px;background:var(--line)}
.process-steps li::after{content:"";position:absolute;top:-4px;left:0;width:44px;height:10px;background:var(--navy)}
.step-num{font-family:var(--serif);font-size:2.4rem;color:var(--silver);display:block;margin-bottom:8px;line-height:1}
.process-steps h3{color:var(--navy);margin-bottom:10px;font-size:1.2rem}
.process-steps p{font-size:.9rem;color:var(--steel)}

/* ---------- Proyectos ---------- */
.projects{background:var(--mist)}
.filters{display:flex;flex-wrap:wrap;justify-content:center;gap:10px;margin-bottom:38px}
.filter{
  font-family:var(--font);font-size:.84rem;font-weight:600;letter-spacing:.02em;
  padding:10px 22px;border:1.5px solid var(--line);background:#fff;color:var(--steel);
  border-radius:40px;cursor:pointer;transition:.25s var(--ease)
}
.filter:hover{border-color:var(--navy);color:var(--navy)}
.filter.is-active{background:var(--navy);border-color:var(--navy);color:#fff}
.gallery{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.gcard{
  position:relative;overflow:hidden;border-radius:var(--radius);cursor:pointer;
  aspect-ratio:4/3;box-shadow:var(--shadow-sm)
}
.gcard img{width:100%;height:100%;object-fit:cover;transition:.6s var(--ease)}
.gcard:hover img{transform:scale(1.08)}
.gcard figcaption{
  position:absolute;inset:0;display:flex;flex-direction:column;justify-content:flex-end;
  padding:22px;color:#fff;font-weight:600;font-size:1rem;
  background:linear-gradient(0deg,rgba(15,31,58,.82) 0%,rgba(15,31,58,.1) 55%,transparent 100%);
  opacity:0;transition:.4s var(--ease)
}
.gcard:hover figcaption{opacity:1}
.gcard figcaption span{
  font-size:.68rem;font-weight:600;letter-spacing:.16em;text-transform:uppercase;
  color:var(--silver);margin-bottom:5px
}
.gcard.hide{display:none}

/* ---------- CTA band ---------- */
.cta-band{background:var(--graphite);color:#fff;padding:clamp(50px,7vw,80px) 0}
.cta-inner{display:flex;align-items:center;justify-content:space-between;gap:30px;flex-wrap:wrap}
.cta-inner h2{color:#fff;margin:6px 0 8px}
.cta-inner p{color:rgba(255,255,255,.72);max-width:460px}

/* ---------- FAQ ---------- */
.faq{background:var(--white)}
.faq-wrap{max-width:820px;margin:0 auto}
.accordion{margin-top:10px}
.acc-item{border-bottom:1px solid var(--line)}
.acc-q{
  width:100%;text-align:left;background:none;border:0;cursor:pointer;
  font-family:var(--font);font-weight:600;font-size:1.02rem;color:var(--graphite);
  padding:24px 0;display:flex;align-items:center;justify-content:space-between;gap:20px
}
.acc-ico{position:relative;width:16px;height:16px;flex-shrink:0}
.acc-ico::before,.acc-ico::after{content:"";position:absolute;background:var(--navy);transition:.3s var(--ease)}
.acc-ico::before{top:7px;left:0;width:16px;height:2px}
.acc-ico::after{top:0;left:7px;width:2px;height:16px}
.acc-q[aria-expanded="true"] .acc-ico::after{transform:rotate(90deg);opacity:0}
.acc-a{max-height:0;overflow:hidden;transition:max-height .35s var(--ease)}
.acc-a p{padding:0 0 24px;color:var(--steel);font-size:.95rem;max-width:92%}

/* ---------- Contacto ---------- */
.contact{background:var(--navy);color:#fff}
.contact-grid{display:grid;grid-template-columns:1fr 1fr;gap:clamp(36px,6vw,70px);align-items:start}
.contact-info h2{color:#fff;margin-bottom:18px}
.contact-info .lead{color:rgba(255,255,255,.82);margin-bottom:34px}
.contact-list{margin-bottom:32px}
.contact-list li{padding:18px 0;border-bottom:1px solid rgba(255,255,255,.12);display:flex;flex-direction:column;gap:4px}
.ci-label{font-size:.7rem;font-weight:600;letter-spacing:.18em;text-transform:uppercase;color:var(--silver)}
.contact-list a,.contact-list span:not(.ci-label){font-size:1.1rem;font-weight:500;color:#fff}
.contact-list a:hover{color:var(--silver)}

.contact-form{background:#fff;border-radius:var(--radius);padding:clamp(26px,4vw,40px);box-shadow:var(--shadow-lg)}
.field{margin-bottom:18px}
.field-row{display:grid;grid-template-columns:1fr 1fr;gap:16px}
.field label{display:block;font-size:.78rem;font-weight:600;letter-spacing:.06em;text-transform:uppercase;color:var(--steel);margin-bottom:8px}
.field input,.field select,.field textarea{
  width:100%;font-family:var(--font);font-size:.95rem;color:var(--graphite);
  padding:13px 15px;border:1.5px solid var(--line);border-radius:var(--radius);
  background:var(--mist);transition:.25s var(--ease)
}
.field input:focus,.field select:focus,.field textarea:focus{
  outline:none;border-color:var(--navy);background:#fff;box-shadow:0 0 0 3px rgba(20,41,77,.08)
}
.field textarea{resize:vertical}
.contact-form .btn{margin-top:8px}
.form-note{font-size:.78rem;color:var(--steel-light);text-align:center;margin-top:14px}

/* ---------- Footer ---------- */
.site-footer{background:var(--graphite);color:rgba(255,255,255,.7);padding:60px 0 30px}
.footer-grid{display:grid;grid-template-columns:1.6fr 1fr 1fr 1fr;gap:36px;padding-bottom:40px;border-bottom:1px solid rgba(255,255,255,.1)}
.footer-logo{height:42px;margin-bottom:18px}
.footer-brand p{font-size:.9rem;max-width:320px}
.footer-col h4{color:#fff;font-size:.78rem;letter-spacing:.14em;text-transform:uppercase;margin-bottom:16px;font-weight:600}
.footer-col a{display:block;font-size:.9rem;padding:6px 0;color:rgba(255,255,255,.7);transition:.2s}
.footer-col a:hover{color:var(--silver);padding-left:4px}
.footer-bottom{display:flex;justify-content:space-between;flex-wrap:wrap;gap:10px;padding-top:24px;font-size:.8rem;color:rgba(255,255,255,.5)}

/* ---------- WhatsApp float ---------- */
.wa-float{
  position:fixed;bottom:22px;right:22px;z-index:90;width:58px;height:58px;border-radius:50%;
  background:var(--wa);color:#fff;display:flex;align-items:center;justify-content:center;
  box-shadow:0 10px 30px rgba(37,211,102,.45);transition:.3s var(--ease);
  animation:waPulse 2.6s infinite
}
.wa-float:hover{transform:scale(1.08)}
@keyframes waPulse{0%{box-shadow:0 10px 30px rgba(37,211,102,.45),0 0 0 0 rgba(37,211,102,.4)}70%{box-shadow:0 10px 30px rgba(37,211,102,.45),0 0 0 16px rgba(37,211,102,0)}100%{box-shadow:0 10px 30px rgba(37,211,102,.45),0 0 0 0 rgba(37,211,102,0)}}

/* ---------- Lightbox ---------- */
.lightbox{
  position:fixed;inset:0;z-index:200;background:rgba(15,31,58,.94);
  display:none;align-items:center;justify-content:center;padding:40px
}
.lightbox.open{display:flex}
.lightbox img{max-width:92vw;max-height:86vh;border-radius:var(--radius);box-shadow:var(--shadow-lg)}
.lb-close,.lb-nav{position:absolute;background:none;border:0;color:#fff;cursor:pointer;transition:.2s}
.lb-close{top:20px;right:26px;font-size:2.4rem;line-height:1}
.lb-nav{top:50%;transform:translateY(-50%);font-size:3rem;width:60px}
.lb-prev{left:10px}.lb-next{right:10px}
.lb-close:hover,.lb-nav:hover{color:var(--silver)}

/* ---------- Reveal animation ---------- */
.reveal{opacity:0;transform:translateY(28px);transition:.7s var(--ease)}
.reveal.in{opacity:1;transform:none}

/* ===================================================================
   RESPONSIVE
=================================================================== */
@media (max-width:1024px){
  .pillars-grid{grid-template-columns:1fr 1fr;gap:24px}
  .pillar{border-left:0;padding:0}
  .pillar:nth-child(2)::before{content:none}
  .process-steps{grid-template-columns:1fr 1fr;gap:30px}
  .footer-grid{grid-template-columns:1fr 1fr}
}

@media (max-width:820px){
  .nav{
    position:fixed;top:0;right:0;height:100vh;width:min(78vw,320px);
    flex-direction:column;align-items:flex-start;justify-content:center;gap:8px;
    background:var(--navy);padding:40px 34px;transform:translateX(100%);
    transition:.4s var(--ease);box-shadow:-20px 0 60px rgba(0,0,0,.3)
  }
  .nav.open{transform:translateX(0)}
  .nav a{font-size:1.1rem;padding:12px 0;width:100%;border-bottom:1px solid rgba(255,255,255,.1)}
  .nav a::after{display:none}
  .nav-cta-mobile{display:block;color:var(--silver)!important}
  .nav-toggle{display:flex}
  .site-header:not(.scrolled){background:linear-gradient(180deg,rgba(15,31,58,.6),transparent)}
  .about-grid,.why-grid,.contact-grid{grid-template-columns:1fr}
  .services-grid{grid-template-columns:1fr;max-width:440px;margin:0 auto}
  .gallery{grid-template-columns:1fr 1fr;gap:12px}
  .about-media img{min-height:340px}
  .why-list{gap:0}
  .cta-inner{flex-direction:column;align-items:flex-start}
}

@media (max-width:560px){
  .container{padding:0 18px}
  .header-actions .btn-primary{display:none}
  .pillars-grid{grid-template-columns:1fr}
  .mv-grid{grid-template-columns:1fr}
  .process-steps{grid-template-columns:1fr}
  .why-list{grid-template-columns:1fr}
  .field-row{grid-template-columns:1fr}
  .gallery{grid-template-columns:1fr}
  .footer-grid{grid-template-columns:1fr}
  .about-badge{right:12px;bottom:-18px}
  .hero-content{padding-top:100px}
  .about-media img{min-height:280px}
}

@media (prefers-reduced-motion:reduce){
  *{animation:none!important}
  .reveal{opacity:1;transform:none;transition:none}
  html{scroll-behavior:auto}
}