* { 
    font-family: "Noto Sans Lao", sans-serif;
    font-optical-sizing: auto;
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}
html{
    font-style: normal;
    margin: auto;
    width: 100%;
}
body {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}
/* contract school */
.contract{
    display: flex;
    justify-content: start;
    position: relative;
    z-index: 10;
    background: rgb(5, 188, 188);
}
.contract img{
    padding-top: 0.1rem;
    border-radius: 100%;
    width: 2rem;
    margin: 0.5rem;
}

/* logo and menu */
/* logo */
nav{
    background: white;
    top: 0;
    left: 0;
    position: sticky;

    z-index: 1000;

    display: flex;
    padding: 0.5rem;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 2px 10px -5px black ;
    z-index: 1000;
}
.logo{
    display:flex;
    align-items: center;
    padding-left: 0.5rem;
}
.logo h2{
    display: flex;
    justify-content: center;
    text-align: center;
    font-size: clamp(0.5rem,calc(5vh+1rem),1.2rem);
    padding: min(0.5em);
    margin: 0;
    line-height: 1.2;
}
.logo a img{
    display: block;
    border-radius: 100%;
    width: 100px;
}
/* menu */
.allmenu{
    display: flex;
    flex-direction: row;
    align-items: center;
    gap: 2rem;
    position: relative;
}
.menu{
    position: relative;
    margin-right: 2rem;
}
.menu-btn{
    font-size: 1.2rem;
    text-decoration: none;
    border: none;
    background: white;
    cursor: pointer;
    position: relative;
}
ul {
    list-style: none;
    margin: 0;
    padding: 0;
}
.dropdown{
    position: absolute;
    color: black;
    left: auto;
    margin: 0;
    border-top: 2px solid blue;
    width: 10rem;
    
    overflow-wrap: break-word;
    opacity: 0;
    transform: translateY(10px);
    transition: all 0.5s ease ;
    background:white;
}
.dropdown li{
    padding-top: 5px;
}
a{
    font-size: 1.2rem;
    color: black;
    text-decoration: none;
}
.menu:hover .dropdown{
    opacity: 1;
    transform: translateY(0);
}
.hamburger{
    display: none;
    font-size: 28px;
    cursor: pointer;
    padding: 10px;
    align-items: center;
}
.overlay{
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: black;
    opacity: 0;
    pointer-events: none;
    transition:  0.3s;
}
.overlay.show{
    opacity: 0.3;
    pointer-events: auto;
}
@media(max-width:768px){
    .hamburger{
        display: block;
        padding: 1rem;
    }
    .allmenu{
        position: fixed;
        top: 0;
        right: -260px;
        width: 260px;
        height:100%;
        background: white;
        flex-direction: column;
        padding: 20px;
        transition: 0.3s;
        z-index: 10000;
        overflow-y:auto ;
    }

    /* open menu */
    .allmenu.show{
        right: 0;
    }
    
    .dropdown{
    position: relative;
    list-style: none;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3 ease;
    background: white;
    }

    
    #btn-active{
    color: black;
    padding-bottom: 0.1rem;
    border-bottom: none;
    }
    .dropdown.show{
        max-height: 300px;
        opacity: 1;
        transform: translateY(0);
    }
}
/* main */
/* ກຸ່ມສາລະຕ່າງໆ */
/* ===== MAIN ===== */
main{
    display: flex;
    flex-direction: column;
    width: 100%;
    flex: 1;
}
.main-context{
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
    padding: 4rem ;
}
.main-context h1{
    border-bottom: 2px solid pink ;
}


/* ===== TEACHER CARD ===== */
.teachers-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
    gap: 1.5rem;
    padding: 2rem;
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
}

.teacher-card {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
    text-align: center;
    padding-bottom: 1rem;
    transition: transform 0.3s;
}

.teacher-card:hover {
    transform: translateY(-5px);
}

.teacher-card img {
    width: 100%;
    height: 250px;
    object-fit: cover;
}

.teacher-card h3 {
    padding: 0.8rem 0.5rem 0.3rem;
    font-size: 1rem;
    color: black;
}

.teacher-card p {
    font-size: 0.85rem;
    color: gray;
    padding: 0 0.5rem;
}

/* ===== TEACHER LIST TITLE ===== */
.teacher-list {
    padding: 1.5rem 2rem 0.5rem;
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
}

.teacher-list h1 {
    font-size: 1.3rem;
    border-bottom: 3px solid rgb(5, 188, 188);
    display: inline-block;
    padding-bottom: 0.3rem;
    color: black;
}

/* ===== MOBILE ===== */
@media (max-width: 768px) {
    .teachers-container {
        grid-template-columns: repeat(2, 1fr);
        padding: 1rem;
    }
    .teacher-card img {
        height: 140px;
    }
}
/* footer */
.footer{
    padding: 2rem;
    background: blue;
    color: aliceblue;
    border-top: 4px solid white;
}

.footer-logo {
    display: flex;
    align-items: center;
    justify-content: center;
    margin: auto;
}

.footer-logo img {
    border-radius: 100%;
    width: 10rem;
}

/* text footer */

.text-address-phone{
    display: flex;
    align-items: center;
    justify-content: center;
    margin-top: 1rem;
}

.phone-address{
    font-size: 1.2rem;
}

.text-contract-email{
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 1.2rem;
}

.email{
    font-size: 0.8rem;
}