*{
    margin: 0;
    padding:0;
}
*,*::before,*::after{
    box-sizing: border-box;
}
body{
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    color: black;
    line-height: 1.6;
}
#logo{
    color:#1a252f;
    font-size: 1.8rem;
}
#logo span{
    color: #3498db;
}
.encabezado-principal{
    background-color: #ffffff;
    padding: 15px 5%;
    border-bottom: 1px solid #eee;
    display: flex;
    justify-content: space-between;
    align-items: center;

}
.menu-nav ul{
    list-style: none;
    display: flex;
    gap: 20px;
}
.menu-nav a{
    text-decoration: none;
    color: #2c3e50;
    font-weight: 600;
    display: inline-block;
    padding: 5px 10px;

}

.banner-oferta{
    background-color: #F39c12;
    color: #ffffff;
    text-align: center;
    padding: 10px 15px;
    border-bottom: 3px solid #d35400;
    font-weight: bold;
    font-size: 0.9rem;
    position: sticky;
    top: 0;
    z-index: 100;
}
.tarjeta-curso{
    background-color: #ffffff;
    width: 100%;
    max-width: 350px;
    padding: 25px;
    margin: 15px 0;
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    box-shadow: 0 4px 6px ;
    transition: transform 0.3s ease, box-shadow 0.3s ease ;            
}
.tarjeta-curso h3{
    font-size: 1.4rem;
    color: #2c3e50;
    margin-top: 10px;
}
.tarjeta-curso p{
    color: #555;
}
.precio{
    display: inline-block;
    margin-top: 15px;
    font-size: 1.2rem;
    font-weight: bold;
    color: #27ae60;
}



.seccion-cursos{
    padding: 4px 5%;

}
.grid-cursos{
    display: grid;
    grid-template-columns: repeat(auto-fit,minmax(250px,1fr));
    gap: 50px;
    margin-top: 20px;
}
@media(max-width:720px){
    .encabezado-principal{
        flex-direction: column;
        gap: 15px;
        text-align: center;
    }
    .hero h2{
        font-size: 1.5rem;
    }
    .grid-cursos{
        grid-template-columns: 1 fr;
    }
    
}
.subtitulo{

    color: blue;
}
.hero {
    background: linear-gradient(135deg,#2c3e50,#3498db);
    color: #ffffff;
    padding: 60px 20px;
    text-align: center;        
}
.hero h2{
    color: #ffffff;
}
.hero .subtitulo{
    color: #ecf0f1;
}
.btn-principal{
    background-color: #27ae60;
    color: #ffffff;
    border: none;
    padding: 15px 25px;
    font-size: 1rem;
    font-weight: bold;
    border-radius: 5px;
    margin-top: 15px;
    transition: background-color 0.2s;
}
.btn-principal:hover{
    background-color: #219050;
}
.btn-principal:focus{
    outline: 3px solid #219050;
}
.tarjeta-curso:hover{
    transform: translateY(-8px);
    box-shadow: 0 12px 20px rgba(0,0,0,0.15);
}

.tarjeta-curso.destacados {
    border: 2px solid #3498db;
    position: relative;
}

.etiqueta-popular {
    position: absolute;
    top: -12px;
    right: 20px;
    background-color: #e74c3c;
    color: #ffffff;
    font-size: 0.8rem;
    font-weight: bold;
    padding: 4px 10px;
    border-radius: 4px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.2);
}
.pie-pagina{
    background-color: #1a252f;
    color: #ffffff;
    text-align: center;
    padding: 20px;
    margin-top: 40px;
}