/* ======================================================
   SISTEMA VISUAL INSTITUCIONAL – CSN STYLE
   ====================================================== */

:root{
  --bg:#eef3f9;
  --surface:#ffffff;
  --surface-2:#f8fbff;
  --text:#0f1728;
  --muted:#5e6b7f;

  --csn-blue:#0a2c63;
  --csn-blue-2:#123f86;
  --csn-blue-3:#1b5fbf;
  --csn-line:#dbe4f0;

  --shadow-sm:0 4px 14px rgba(15, 23, 42, .06);
  --shadow-md:0 10px 30px rgba(15, 23, 42, .10);
  --shadow-lg:0 20px 60px rgba(11, 42, 91, .18);

  --radius-sm:10px;
  --radius-md:16px;
  --radius-lg:24px;

  --max:1180px;
}

*{
  box-sizing:border-box;
}

html{
  scroll-behavior:smooth;
}

body{
  margin:0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Arial, sans-serif;
  color:var(--text);
  background:
    radial-gradient(circle at top right, rgba(27,95,191,.08), transparent 28%),
    linear-gradient(180deg, #f4f8fc 0%, #eef3f9 100%);
  line-height:1.6;
}

a{
  color:var(--csn-blue-3);
  text-decoration:none;
}

a:hover{
  text-decoration:underline;
}

img{
  max-width:60%;
  height:auto;
}

.wrap{
  width:100%;
  max-width:var(--max);
  margin:auto;
  padding:0 20px;
}

.muted{
  color:var(--muted);
}

/* ======================================================
   HEADER
   ====================================================== */

.header{
  position:relative;
  overflow:hidden;
  background:
    linear-gradient(135deg, rgba(10,44,99,.98) 0%, rgba(18,63,134,.96) 62%, rgba(27,95,191,.92) 100%);
  color:#fff;
  box-shadow:var(--shadow-md);
}

.header::before{
  content:"";
  position:absolute;
  inset:auto -120px -120px auto;
  width:420px;
  height:420px;
  border-radius:50%;
  background:radial-gradient(circle, rgba(255,255,255,.16), rgba(255,255,255,0) 70%);
  pointer-events:none;
}

.header::after{
  content:"";
  position:absolute;
  left:-140px;
  top:-120px;
  width:360px;
  height:360px;
  border-radius:50%;
  background:radial-gradient(circle, rgba(255,255,255,.08), rgba(255,255,255,0) 70%);
  pointer-events:none;
}

.header-inner{
  position:relative;
  z-index:1;
  padding:22px 0 20px;
}

.brandbar{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:24px;
}

.brand{
  display:flex;
  align-items:center;
  gap:22px;
}

.brand-logo-wrap{
  flex:0 0 auto;
  display:flex;
  align-items:center;
  justify-content:center;
  padding:10px 14px;
  border-radius:18px;
  background:rgba(255,255,255,.96);
  border:1px solid rgba(255,255,255,.22);
  box-shadow:0 10px 26px rgba(0,0,0,.14);
}

.brand-logo{
  display:block;
  width:240px;
  max-width:70%;
  height:auto;
}

.brand-copy h1{
  margin:0;
  font-size:28px;
  line-height:1.08;
  font-weight:800;
  letter-spacing:-0.3px;
  color:#fff;
  max-width:760px;
}

.brand-copy p{
  margin:8px 0 0;
  font-size:15px;
  color:rgba(255,255,255,.86);
}

.nav{
  display:flex;
  flex-wrap:wrap;
  gap:10px;
  padding-top:18px;
  margin-top:18px;
  border-top:1px solid rgba(255,255,255,.18);
}

.nav a{
  color:#fff;
  font-weight:650;
  font-size:14px;
  padding:10px 14px;
  border-radius:999px;
  background:rgba(255,255,255,.08);
  border:1px solid rgba(255,255,255,.10);
  backdrop-filter:blur(6px);
  transition:.18s ease;
}

.nav a:hover{
  text-decoration:none;
  transform:translateY(-1px);
  background:rgba(255,255,255,.15);
}

/* ======================================================
   HERO
   ====================================================== */

.hero-shell{
  margin-top:-22px;
  position:relative;
  z-index:2;
}

.hero{
  background:linear-gradient(180deg, rgba(255,255,255,.96), rgba(255,255,255,1));
  border:1px solid rgba(219,228,240,.9);
  border-radius:var(--radius-lg);
  box-shadow:var(--shadow-lg);
  overflow:hidden;
}

.hero-grid{
  display:grid;
  grid-template-columns:1.25fr .95fr;
  gap:0;
}

.hero-main{
  padding:42px 38px 36px;
}

.eyebrow{
  display:inline-flex;
  align-items:center;
  gap:8px;
  padding:8px 12px;
  border-radius:999px;
  background:#edf4ff;
  border:1px solid #d9e7ff;
  color:var(--csn-blue);
  font-size:12px;
  font-weight:750;
  letter-spacing:.3px;
  text-transform:uppercase;
}

.hero h2{
  margin:18px 0 12px;
  font-size:40px;
  line-height:1.08;
  letter-spacing:-.5px;
}

.hero-lead{
  font-size:18px;
  color:#324258;
  max-width:760px;
  margin:0 0 22px;
}

.hero-actions{
  display:flex;
  flex-wrap:wrap;
  gap:12px;
  margin-top:20px;
}

.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:8px;
  min-height:46px;
  padding:12px 18px;
  border-radius:12px;
  text-decoration:none;
  font-weight:750;
  font-size:14px;
  border:1px solid transparent;
  transition:.18s ease;
  box-shadow:var(--shadow-sm);
  cursor:pointer;
}

.btn:hover{
  text-decoration:none;
  transform:translateY(-1px);
}

.btn.primary{
  background:linear-gradient(180deg, var(--csn-blue-3), var(--csn-blue));
  color:#fff;
}

.btn.secondary{
  background:#eef4fb;
  color:var(--csn-blue);
  border-color:#d8e4f2;
}

.btn.ghost{
  background:#fff;
  color:var(--text);
  border-color:#dde6f1;
}

.hero-stats{
  display:flex;
  flex-wrap:wrap;
  gap:12px;
  margin-top:24px;
}

.stat{
  min-width:150px;
  background:var(--surface-2);
  border:1px solid var(--csn-line);
  border-radius:14px;
  padding:12px 14px;
}

.stat strong{
  display:block;
  font-size:15px;
  color:var(--csn-blue);
  margin-bottom:2px;
}

.stat span{
  display:block;
  font-size:13px;
  color:var(--muted);
}

.hero-side{
  position:relative;
  padding:30px;
  background:
    linear-gradient(180deg, rgba(10,44,99,.95), rgba(18,63,134,.92)),
    radial-gradient(circle at top right, rgba(255,255,255,.16), transparent 35%);
  color:#fff;
  display:flex;
  flex-direction:column;
  justify-content:space-between;
}

.hero-panel{
  background:rgba(255,255,255,.10);
  border:1px solid rgba(255,255,255,.16);
  border-radius:20px;
  padding:22px;
  backdrop-filter:blur(8px);
  box-shadow:inset 0 1px 0 rgba(255,255,255,.08);
}

.hero-panel h3{
  margin:0 0 10px;
  font-size:18px;
}

.hero-panel p{
  margin:0 0 16px;
  color:rgba(255,255,255,.86);
}

.mini-list{
  margin:0;
  padding-left:18px;
}

.mini-list li{
  margin-bottom:8px;
  color:rgba(255,255,255,.92);
}

.mini-list a{
  color:#fff;
}

.cover-card{
  margin-top:18px;
  background:rgba(255,255,255,.08);
  border:1px solid rgba(255,255,255,.14);
  border-radius:20px;
  padding:18px;
}

.cover-thumb{
  height:220px;
  border-radius:16px;
  background:
    linear-gradient(180deg, rgba(255,255,255,.08), rgba(255,255,255,.02)),
    linear-gradient(135deg, #163a73, #0b2a5b 60%, #0a2550);
  border:1px solid rgba(255,255,255,.12);
  position:relative;
  overflow:hidden;
}

.cover-thumb::before{
  content:"";
  position:absolute;
  inset:18px;
  border-radius:12px;
  border:1px solid rgba(255,255,255,.10);
}

.cover-thumb::after{
  content:"CSN • Modelo de Amenaza Sísmica";
  position:absolute;
  left:22px;
  bottom:18px;
  right:22px;
  color:#fff;
  font-weight:800;
  font-size:18px;
  line-height:1.2;
}

.cover-caption{
  margin-top:12px;
  font-size:13px;
  color:rgba(255,255,255,.82);
}

/* ======================================================
   MAIN CONTENT
   ====================================================== */

.main{
  padding:30px 0 60px;
}

.section{
  margin-top:22px;
}

.grid{
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:22px;
}

.card{
  background:rgba(255,255,255,.92);
  border:1px solid var(--csn-line);
  border-radius:20px;
  box-shadow:var(--shadow-md);
  overflow:hidden;
}

.card-header{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:16px;
  padding:18px 22px;
  border-bottom:1px solid var(--csn-line);
  background:linear-gradient(180deg, #fbfdff, #f5f9fe);
}

.card-header h3{
  margin:0;
  font-size:18px;
  line-height:1.2;
}

.card-header .small{
  font-size:13px;
  color:var(--muted);
}

.card-body{
  padding:22px;
}

.card-body p:first-child{
  margin-top:0;
}

.card-body p:last-child{
  margin-bottom:0;
}

.list-clean{
  margin:0;
  padding-left:20px;
}

.list-clean li{
  margin-bottom:10px;
}

.list-clean a{
  font-weight:600;
}

.download-group{
  display:flex;
  flex-wrap:wrap;
  gap:10px;
  margin-top:10px;
}

.feature-band{
  margin-top:22px;
  display:grid;
  grid-template-columns:repeat(3, 1fr);
  gap:18px;
}

.feature{
  background:rgba(255,255,255,.78);
  border:1px solid var(--csn-line);
  border-radius:18px;
  padding:18px;
  box-shadow:var(--shadow-sm);
}

.feature h4{
  margin:0 0 8px;
  font-size:16px;
}

.feature p{
  margin:0;
  color:var(--muted);
  font-size:14px;
}

/* ======================================================
   FOOTER
   ====================================================== */

.footer{
  margin-top:40px;
  background:linear-gradient(180deg, #0a244f, #071a3b);
  color:#d3def0;
}

.footer .wrap{
  padding:26px 20px;
}

.footer strong{
  color:#fff;
}

.footer p{
  margin:.35rem 0;
}

.footer-tight{
  margin-top:0;
}

/* ======================================================
   VISOR
   ====================================================== */

.viewer-shell{
  padding:26px 0 40px;
}

.viewer-toolbar{
  display:flex;
  justify-content:space-between;
  align-items:center;
  gap:16px;
  margin-bottom:16px;
  flex-wrap:wrap;
}

.viewer-toolbar h2{
  margin:0;
  font-size:26px;
  line-height:1.15;
}

.viewer-toolbar p{
  margin:4px 0 0;
  color:var(--muted);
}

.viewer-actions{
  display:flex;
  flex-wrap:wrap;
  gap:10px;
}

.viewer-box{
  background:#fff;
  border:1px solid var(--csn-line);
  border-radius:22px;
  box-shadow:var(--shadow-lg);
  overflow:hidden;
}

.viewer{
  width:100%;
  height:82vh;
  border:0;
  display:block;
}

/* ======================================================
   RESPONSIVE
   ====================================================== */

@media (max-width: 1024px){
  .hero-grid{
    grid-template-columns:1fr;
  }

  .hero h2{
    font-size:34px;
  }

  .feature-band{
    grid-template-columns:1fr;
  }

  .brand-logo{
    width:280px;
  }

  .brand-copy h1{
    font-size:24px;
  }
}

@media (max-width: 760px){
  .brandbar{
    align-items:flex-start;
  }

  .brand{
    align-items:flex-start;
    flex-direction:column;
    gap:14px;
  }

  .brand-logo-wrap{
    padding:8px 10px;
    border-radius:14px;
  }

  .brand-logo{
    width:230px;
  }

  .brand-copy h1{
    font-size:22px;
  }

  .hero-main,
  .hero-side{
    padding:26px 22px;
  }

  .hero h2{
    font-size:28px;
  }

  .hero-lead{
    font-size:16px;
  }

  .grid{
    grid-template-columns:1fr;
  }

  .viewer{
    height:76vh;
  }
}