* {
    margin: 0;
    padding:0;
}

:root {
    --green: rgb(178, 223, 40);
    --dark-blue: rgb(10, 24, 35);
    --light-blue: rgb(0, 181, 204);
    --white: rgb(240, 248, 255);
}

body {    
    color: var(--dark-blue);
    font-family: monospace;
    background-image: url(img/background.jpg);
    background-color: var(--dark-blue);
    background-size: fill;    
    font-family: monospace;     
}

header { 
    display: flex;
    justify-content: center;
    align-items: center; 
    flex-wrap: nowrap;
    flex-direction: column;
    width: 100%;          
}

.nav-header {
    display: flex;
    justify-content: center;    
    width: 100%;
}

.btn-header { 
    margin: 25px; 
    background-color: var(--light-blue);
    border-radius: 20px;
    border: none;
    color: var(--dark-blue);
    width: 12vw; 
    height: 40px;     
    font-size: large; 
    cursor: pointer;
}

.btn-header:hover {
    opacity: 0.5;
}

.header-text {
    color: var(--white);
    margin-top: 2vh;
    width: 100%;
    -webkit-text-stroke-width: 1px; 
    -webkit-text-stroke-color: rgb(102, 217, 31);    
    text-align: center;
}

main {
    display: flex;  
    flex-wrap: wrap;     
    justify-content: center;
    align-items: center;
    align-content: center;    
}

.card {
    height: 67vh;
    width: 27vw;    
    margin: 8vh;
    padding: 2vh 1vw;    
    border-radius: 80px;
    background-color: var(--green);  
    display: flex;  
    flex-direction: column;
    justify-content: flex-start;                      
    text-align: center;
    align-items: center;
    align-content: center;
    font-size: 1rem;
    color:var(--dark-blue);    
    cursor: pointer;
    text-decoration: none;
}

.card:hover {
    opacity: 0.8;
}

.card-img {
    height: 72vh;
    width: 24vw;
    margin: 2vh;
    border-radius: 70px;
    border: var(--dark-blue) 2px solid;
}

ul li {
    font-size: 1rem; 
    margin: 1vh;        
}

@media screen and (max-width: 480px)  {
    .btn-header { 
        width: 25vw;
    }

    .card {        
        border-radius: 60px;
        width: 50vw;
        height: 66vh;
    }

    .card-img {
        width: 41vw;
        border-radius: 60px;
    }
}

@media screen and (min-width: 481px) and (max-width: 768px) {
    .btn-header { 
        width: 30vw;
    }

    .card {        
        width: 65vw;        
        height: 53vh;
    }

    .card-img {
        width: 55vw;        
    }
}

@media screen and (min-width: 769px) and (max-width: 1024px) {    
    .btn-header { 
        width: 25vw;
    }

    .card {        
        width: 58vw;        
        height: 55vh;
        
    }

    .card-img {
        width: 50vw;        
    }

    ul li {
        font-size: 1.3rem; 
                
    }
}