*{
    margin: 0;
    padding: 0;
    font-family: Arial, Helvetica, sans-serif;
}

.header{
    min-height: 100vh;
    width: 100%;
    background-image: linear-gradient(rgba(4,9,30,0.7),rgba(4,9,30,0.7)),url(images/background.jpg);
    background-position: center;
    background-size: cover;
    position: relative;
}

nav{
    display: flex;
    padding: 2% 6%;
    justify-content: space-between;
    align-items: center;
}


.nav-links{
    
    flex: 1;
    text-align: right;
}

.nav-links ul li{
  
    list-style: none;
    display: inline-block;
    padding: 8px 12px;
    position: relative;
}

.nav-links ul li a{
    color: #fff;
    text-decoration: none;
    font-size: 15px;
}

.nav-links ul li::after{
    content: '';
    width: 0%;
    height: 2px;
    background: #6c124c;
    display: block;
    margin: auto;
}

.nav-links ul li:hover::after{
    width: 100%;
}

.text-box{
    width: 90%;
    color: #fff;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%,-50%);
    text-align: center; 
}

.text-box h1{
    font-size: 62px;
}

.text-box p{
    font-size: 25px;
    margin: 10px 0 40px;
    color: #fff;
}

.open-btn{
    display: inline-block;
    text-decoration: none;
    color: #fff;
    border: 1px solid #fff;
    padding: 12px 34px;
    font-size: 13px;
    background: transparent;
    position: relative;
    cursor: pointer;
}

.open-btn:hover{
    border: 1px solid #6c124c; 
    background-color: #6c124c;
    transition: 1s;
}

nav .bi{
    display: none;
}

/* MOBILE SCREEN */
@media (max-width: 600px){
    .text-box h1{
        font-size: 40px;
    }

    .text-box p{
        font-size: 22px;
    }

    .nav-links ul li{
        display: block;
    }

    .nav-links{
        background-color: darkslategray;
        position: absolute;
        height: 100vh;
        width: 200px;
        top: 0;
        right: -200px;
        text-align: left;
        z-index: 2;
        transition: 1s; /*tung sa TOGGLE*/
    }

    nav .bi{
        display: block; /*VISIBLLE*/
        color: #fff;
        margin: 10px;
        font-size: 22px;
        cursor: pointer;
    }
    
    .nav-links ul{
        padding: 20px;
    }

} 



/* INFORMATION */

.t{
    text-align: center;

}

.information{
    width: 80%;
    margin: auto;
    padding-top: 100px;
}

h1{
    font-size: 36px;
    font-weight: 600;
}

p{
    color: #000000;
    font-size: 14px;
    font-weight: 300;
    line-height: 22px;
    padding: 10px;
}

.row{
    margin-top: 5%;
    display: flex;
    justify-content: space-between;
}

.information-col{
    flex-basis: 31%;
    background-color: beige;
    border-radius: 10px;
    margin-bottom: 5%;
    padding: 20px 12px;
    box-sizing: border-box;
    transition: 0.5s;
}

h3{
    text-align: center;
    font-weight: 600;
    margin: 10px 0;
}

.information-col:hover{
    box-shadow: 0 0 20px 0 rgba(0,0,0,0.2);
}


/* media screen */

@media(max-width: 600px){
    .row{
        flex-direction: column;
    }
}


/* BOOK */
.book{
    top: 50px;
    width: 80%;
    margin: auto;
    text-align: center;
    padding-top: 50px;
}

.book-col{
    flex-basis: 32%;
    border-radius: 10px;
    margin-bottom: 30px;
    position: relative;
    overflow: hidden;;
}

.book-col img{
    width: 100%;
    display: block;
}

.layer{
    background: transparent;
    height: 100%;
    width: 100%;
    position: absolute;
    top: 0;
    left: 0;
    transition: 0.5s;
}

.layer:hover{
    background: #6c124c;
}

.layer h3{
    width: 100%;
    font-weight: 100;
    color: #fff;
    font-size: 20px;
    bottom: 0;
    left: 2%;
    transform: translateY(-50%);
    position: absolute;
    opacity: 0;
    transition: 0.5s;
}

.layer:hover h3{
    bottom: 49%;
    opacity: 1;
}



/* ABOUT */

.about{
    width: 80%;
    margin: auto;
    text-align: center;
    padding-top: 100px;
}

.about-col{
    flex-basis: 31%;
    border-radius: 10px;
    margin-bottom: 5%;
    text-align: left;
}

.about-col img{
    width: 100%;
    border-radius: 10px;
}

.about-col p{
    padding: 0;
    text-align: left;
}

.about-col h3{
    margin-top: 16px;
    margin-bottom: 15px;
    font-size: 20px;
    text-align: center;
}



/* COMMENTS */
.comment{
    width: 80%;
    margin: auto;
    padding-top: 100px;
    text-align: center;
}

.comment-col{
    flex-basis: 44%;
    border-radius: 10px;
    margin-bottom: 5%;
    text-align: left;
    background:white;
    padding: 25px;
    cursor: pointer;
    display: flex;
}

.comment img{
    height: 40px;
    margin-left: 5px;
    margin-right: 30px;
    padding: 5px;
}

.comment-col{
    padding: 0;
}

.comment-col h3{
    size: 13px;
    margin-top: 15px;
    text-align: left;
}


/* MEDIA SCREEN */

@media(max-width: 700px){
    .comment-col img{
        margin-left: 0px;
        margin-right: 15px;
    }
}


/* SEND FEEDBACK */
.feedback{
    margin: 100px auto;
    width: 80%;
    background-image: linear-gradient(rgba(0,0,0,0.7),rgba(0,0,0,0.7)),url(images/tech.png);
    background-position: center;
    background-size: cover;
    border-radius: 10px;
    text-align: center;
    padding: 100px 0; 
}

.feedback h1{
    color: #fff;
    margin-bottom: 40px;
    padding: 0;
}





/* MEDIA SCREEN */
@media(max-width: 700px){
    feedback h1{
        font-size: 20px;
    }
}


/* FOOTER */
.footer{
    width: 100%;
    text-align: center;
    padding: 30px 0;
}

.footer h4{
    margin-bottom: 25px;
    margin-top: 20px;
    font-weight: 600;
}

.icon .bi{
    color: white;
    size: 20px;
    margin: 0 13px;
    cursor: pointer;
    padding: 18px;
}