:root{
  --bg:#f5f8fa;
  --primary:#0c3b64;
  --accent:#00bcd4;
  --card:#ffffff;
  --muted:#6c7a89;
  --maxw:1100px;
}

body{
  margin:0;
  font-family:'Poppins',sans-serif;
  background:var(--bg);
  color:#1d2730;
}

/* HEADER */
.topbar{
  background:linear-gradient(90deg,var(--primary),#0a2f4e);
  color:#fff;
  box-shadow:0 4px 10px rgba(0,0,0,0.15);
}

.topbar .wrap.header-flex{
  max-width:var(--maxw);
  margin:0 auto;
  padding:15px 25px;
  display: flex;
  align-items: center;
  justify-content: space-between; /* distribuye logo/subtitulo a la izquierda y menu a la derecha */
  flex-wrap: nowrap; /* evita dividir en varias filas */
  gap: 20px;
}

/* Logo */
.header-flex .logo {
  width: 55px;
  height: auto;
}

/* Subtítulo */
.header-flex .subtitle {
  font-size: 13px;
  color: #ffffff;
  margin: 0 20px 0 10px; /* espacio entre logo y subtítulo */
  white-space: nowrap; /* evita que el texto se divida */
}

/* NAVBAR LINKS */
.nav{
  display:flex;
  align-items:center;
  gap:16px;
}

.nav a{
  color:#fff;
  text-decoration:none;
  font-weight:500;
  position:relative;
  transition:all .25s ease;
}
.nav a::after{
  content:"";
  position:absolute;
  bottom:-4px;
  left:0;
  width:0%;
  height:2px;
  background:var(--accent);
  transition:width .3s ease;
}
.nav a:hover{
  color:var(--accent);
  transform:scale(1.08);
}
.nav a:hover::after{
  width:100%;
}

/* BOTÓN DE TRADUCCIÓN */
#translateBtn {
  background: #1565c0;
  color: #fff;
  padding: 14px 32px;
  border-radius: 8px;
  font-weight: 600;
  font-size: 1rem;
  cursor: pointer;
  border: none;
  transition: all 0.3s ease;
}

#translateBtn:hover{
  background:#0d47a1;
  transform:scale(1.05);
}

/* HERO centrado */
.hero-banner{
  background:linear-gradient(rgba(0, 23, 46, 0.3), rgba(0, 23, 46, 0.85)),
  url(fondo_banner.avif) no-repeat center center/cover;
  color:#fff;
  text-align:center;
  padding:90px 20px 70px 20px;
  display:flex;
  flex-direction:column;
  justify-content:center;
  align-items:center;
  min-height:88vh;
}
.hero-content{
  transform:translateY(-40px);
}
.hero-banner h1{
  font-size:2.6rem;
  max-width:900px;
  margin-bottom:15px;
  line-height:1.3;
}
.hero-description{
  font-size:1.15rem;
  max-width:800px;
  margin:0 auto 20px auto;
  line-height:1.7;
  opacity:0.95;
  text-align:center;
}
.hero-banner .btn{
  margin-top:30px;
  background:#1565c0;
  color:#fff;
  padding:14px 32px;
  border-radius:8px;
  text-decoration:none;
  font-weight:600;
  font-size:1rem;
  transition:all .3s ease;
}
.hero-banner .btn:hover{
  background:#0d47a1;
  transform:scale(1.05);
}

/* MAIN SECTIONS */
.main{max-width:var(--maxw);margin:0 auto;padding:30px 20px}
.card{
  background:var(--card);
  border-radius:14px;
  padding:25px;
  box-shadow:0 8px 20px rgba(0,0,0,0.05);
  margin-bottom:25px;
  transition:.3s;
}
.card:hover{transform:translateY(-3px);}
h3{color:var(--primary)}
h4{margin-top:18px;color:#0f406e}
ul{margin-left:20px}

/* CARACTERÍSTICAS */
.grid{
  display:grid;
  grid-template-columns:repeat(auto-fit,minmax(220px,1fr));
  gap:20px;
  margin-top:15px;
}
.feature{
  background:#f9fcfd;
  border-radius:10px;
  padding:15px;
  border-left:4px solid var(--accent);
  transition:.3s;
}
.feature:hover{background:#eaf9fb;transform:translateY(-4px)}

/* AUTORES */
.authors{
  display:flex;
  flex-wrap:wrap;
  gap:25px;
  justify-content:center;
  margin-top:15px;
}
.author-card{
  background:#f9fcfd;
  border-radius:12px;
  padding:20px;
  text-align:center;
  width:300px;
  transition:.3s;
  box-shadow:0 4px 10px rgba(0,0,0,0.05);
}
.author-card:hover{
  transform:translateY(-4px);
  background:#eef9fa;
}
.author-card img{
  width:100px;
  height:120px;
  border-radius:50%;
  margin-bottom:20px;
}
.email-box{
  word-wrap:break-word;
  max-width:260px;
  margin:0 auto;
  padding:5px 0;
}
.email-box a{
  color:var(--accent);
  text-decoration:none;
  font-size:14px;
  display:inline-block;
  overflow-wrap:break-word;
  line-height:1.4;
  text-align:center;
}

/* FOOTER */
.footer{
  background:var(--primary);
  color:#fff;
  text-align:center;
  padding:20px 10px;
  margin-top:30px;
}
.footer small{opacity:0.8}

/* ANIMACIÓN */
.fade-in{
  opacity:0;
  transform:translateY(20px);
  animation:fadeUp .8s ease forwards;
}
@keyframes fadeUp{
  from{opacity:0;transform:translateY(20px)}
  to{opacity:1;transform:translateY(0)}
}

/* RESPONSIVE */
@media(max-width:900px){
  .hero-banner h1{font-size:2rem}
  .hero-description{font-size:1rem;padding:0 10px}
  .author-card{width:90%}
  .header-flex{
    flex-direction: column;
    align-items: flex-start;
  }
  .nav{
    flex-wrap: wrap;
    gap: 10px;
  }
}