*{
    margin:0;
    padding:0;
    box-sizing:border-box;
}

html{
    scroll-behavior:smooth;
}

/*BODY*/
body{
    font-family:'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;

    background:
    linear-gradient(
        rgba(255,255,255,.85),
        rgba(255,255,255,.85)),
    url("FONDO-NATURALEZA.jpg");

    background-size:cover;
    background-position:center;
    background-attachment:fixed;

    color:#2d3436;
    line-height:1.6;
}

/*HEADER*/
header{
    display:flex;
    justify-content:space-between;
    align-items:center;

    padding:20px 60px;

    position:sticky;
    top:0;
    z-index:1000;

    background:rgba(255,255,255,.85);

    backdrop-filter:blur(10px);

    box-shadow:
    0 5px 20px rgba(0,0,0,.1);

    border-bottom:
    2px solid rgba(76,175,80,.2);
}

/*LOGO*/
.logo img{
    border-radius:20px;

    transition:.4s;
}

.logo img:hover{
    transform:scale(1.05);
}

/*MENÚ*/
nav{
    display:flex;
    gap:20px;
}

nav a{
    text-decoration:none;

    color:#1b5e20;

    font-weight:bold;

    font-size:17px;

    padding:12px 20px;

    border-radius:30px;

    transition:.4s;
}

nav a:hover{

    background:
    linear-gradient(
        45deg,
        #43a047,
        #66bb6a);

    color:white;

    transform:translateY(-3px);

    box-shadow:
    0 5px 15px rgba(76,175,80,.4);
}

/*TITULO*/
.titulo{
    text-align:center;
    margin:50px auto;
}

.titulo h1{

    display:inline-block;

    padding:25px 60px;

    font-size:42px;

    color:white;

    letter-spacing:2px;

    background:
    linear-gradient(
        135deg,
        #1b5e20,
        #43a047,
        #81c784);

    border-radius:50px;

    box-shadow:
    0 15px 30px rgba(0,0,0,.15);

    transition:.4s;
}

.titulo h1:hover{
    transform:scale(1.03);
}

/*INTRODUCCIÓN*/
.introduccion{

    width:90%;

    margin:30px auto;

    background:white;

    padding:35px;

    border-radius:25px;

    box-shadow:
    0 10px 25px rgba(0,0,0,.1);

    text-align:center;
}

.introduccion h2{
    color:#1b5e20;
    margin-bottom:15px;
}

.introduccion p{
    font-size:17px;
    margin-bottom:10px;
}

/*CONTENEDOR PRINCIPAL*/
.contenedor{

    width:95%;

    margin:auto;

    display:flex;

    justify-content:center;

    align-items:flex-start;

    gap:30px;

    padding:20px;
}

/*COLUMNAS*/
.col{
    flex:1;
}

/*TARJETAS*/
.card{

    display:flex;

    align-items:center;

    gap:18px;

    margin-bottom:25px;

    padding:22px;

    background:white;

    border-radius:25px;

    border-left:8px solid #43a047;

    box-shadow:
    0 10px 25px rgba(0,0,0,.10);

    transition:.4s;
}

.card:hover{

    transform:
    translateY(-10px)
    scale(1.02);

    box-shadow:
    0 20px 35px rgba(0,0,0,.18);
}

/*NÚMEROS*/
.num{

    min-width:60px;
    height:60px;

    display:flex;

    justify-content:center;

    align-items:center;

    border-radius:50%;

    color:white;

    font-size:24px;

    font-weight:bold;

    background:
    linear-gradient(
        135deg,
        #2e7d32,
        #66bb6a);

    box-shadow:
    0 5px 15px rgba(76,175,80,.5);
}

/*ICONOS*/
.icono{

    width:80px;
    height:80px;

    border-radius:50%;

    padding:8px;

    background:#f5fff5;

    border:3px solid #81c784;

    transition:.4s;
}

.card:hover .icono{
    transform:rotate(10deg);
}

/* TEXTO TARJETAS */
.card h3{

    color:#1b5e20;

    margin-bottom:8px;

    font-size:22px;
}

.card p{

    text-align:justify;

    font-size:15px;

    line-height:1.6;
}

/*GALERÍA CENTRAL*/
.centro{

    display:flex;

    flex-direction:column;

    align-items:center;

    gap:25px;
}

.centro img{

    width:260px;

    border-radius:30px;

    padding:10px;

    background:white;

    box-shadow:
    0 15px 30px rgba(0,0,0,.15);

    transition:.5s;
}

.centro img:hover{

    transform:
    scale(1.08)
    rotate(2deg);

    box-shadow:
    0 20px 40px rgba(0,0,0,.25);
}

/*SECCIONES GENERALES*/
section{

    width:90%;

    margin:40px auto;
}

section h2{

    color:#1b5e20;

    margin-bottom:15px;

    text-align:center;
}

/*LISTAS*/
ul,
ol,
dl{

    background:white;

    padding:30px;

    border-radius:20px;

    box-shadow:
    0 8px 20px rgba(0,0,0,.10);
}

ul li,
ol li{

    margin-bottom:10px;

    font-size:16px;
}

dt{

    font-weight:bold;

    color:#2e7d32;

    margin-top:10px;
}

dd{
    margin-left:20px;
}

/*AUDIO Y VIDEO*/
audio,
video{

    display:block;

    margin:20px auto;

    border-radius:15px;

    box-shadow:
    0 10px 20px rgba(0,0,0,.15);
}

/*FORMULARIO*/
form{

    width:700px;

    margin:50px auto;
}

fieldset{

    border:none;

    background:white;

    padding:35px;

    border-radius:30px;

    box-shadow:
    0 15px 35px rgba(0,0,0,.15);
}

legend{

    color:#2e7d32;

    font-size:26px;

    font-weight:bold;
}

label{

    display:block;

    margin-top:15px;

    margin-bottom:5px;

    font-weight:600;
}

input,
textarea{

    width:100%;

    padding:14px;

    border:2px solid #c8e6c9;

    border-radius:12px;

    outline:none;

    transition:.3s;
}

input:focus,
textarea:focus{

    border-color:#43a047;

    box-shadow:
    0 0 10px rgba(76,175,80,.3);
}

textarea{

    height:120px;

    resize:none;
}

/*CHECKBOX*/
input[type="checkbox"]{

    width:auto;

    margin-right:8px;
}

/*BOTÓN*/
button{

    margin-top:15px;

    background:
    linear-gradient(
        45deg,
        #2e7d32,
        #66bb6a);

    color:white;

    border:none;

    padding:15px 30px;

    border-radius:30px;

    font-size:16px;

    font-weight:bold;

    cursor:pointer;

    transition:.4s;
}

button:hover{

    transform:translateY(-4px);

    box-shadow:
    0 10px 20px rgba(76,175,80,.4);
}

/*MENSAJE DEL FORMULARIO*/
#mensaje{

    margin-top:15px;

    font-weight:bold;

    text-align:center;
}

/*FOOTER*/
footer{

    margin-top:50px;

    background:#1b5e20;

    color:white;

    text-align:center;

    padding:30px;
}

footer h4{

    margin-bottom:10px;

    font-size:24px;
}

footer a{

    color:#a5d6a7;

    text-decoration:none;
}

footer a:hover{
    text-decoration:underline;
}

/*RESPONSIVE TABLET*/
@media(max-width:1100px){

    .contenedor{

        flex-direction:column;

        align-items:center;
    }

    .col{
        width:100%;
    }

    .centro img{
        width:220px;
    }

    form{
        width:90%;
    }
}

/*RESPONSIVE CELULAR*/
@media(max-width:768px){

    header{

        flex-direction:column;

        gap:20px;
    }

    nav{

        flex-wrap:wrap;

        justify-content:center;
    }

    .titulo h1{

        font-size:28px;

        padding:20px;
    }

    .logo img{

        width:180px;

        height:auto;
    }

    .centro img{
        width:180px;
    }

    .card{

        flex-direction:column;

        text-align:center;
    }
}