:root{
    --bg:#ffffff;
    --text:#111111;
    --card:#f4f4f4;
    --nav:#ffffff;
    --shadow:rgba(0,0,0,0.1);
}

.dark-mode{
    --bg:#111111;
    --text:#ffffff;
    --card:#1f1f1f;
    --nav:#181818;
    --shadow:rgba(255,255,255,0.08);
}

*{
    margin:0;
    padding:0;
    box-sizing:border-box;
    font-family:Arial, sans-serif;
}

html{
    scroll-behavior:smooth;
}

body{
    background:var(--bg);
    color:var(--text);
    transition:0.3s;
}

nav{
    display:flex;
    justify-content:space-between;
    align-items:center;
    padding:20px 8%;
    background:var(--nav);
    box-shadow:0 2px 10px var(--shadow);
    position:sticky;
    top:0;
}

.logo{
    font-size:28px;
}

nav ul{
    display:flex;
    list-style:none;
    gap:20px;
}

nav a{
    text-decoration:none;
    color:var(--text);
    font-weight:bold;
}

#theme-toggle{
    border:none;
    padding:10px 15px;
    border-radius:10px;
    cursor:pointer;
    background:#333;
    color:white;
}

.hero{
    min-height:90vh;
    display:flex;
    justify-content:center;
    align-items:center;
    gap:50px;
    padding:40px 10%;
}

.hero-image img{
    width:280px;
    border-radius:50%;
    box-shadow:0 10px 20px var(--shadow);
}

.hero-text{
    max-width:600px;
}

.hero-text h1{
    font-size:42px;
    margin-bottom:10px;
}

.hero-text h3{
    margin-bottom:20px;
}

.hero-text p{
    line-height:1.8;
}

.btn{
    display:inline-block;
    margin-top:25px;
    padding:12px 25px;
    background:#333;
    color:white;
    text-decoration:none;
    border-radius:10px;
}

.section{
    padding:80px 10%;
    text-align:center;
}

.section h2{
    margin-bottom:30px;
}

.cards{
    display:grid;
    grid-template-columns:repeat(auto-fit,minmax(180px,1fr));
    gap:20px;
}

.card{
    background:var(--card);
    padding:30px;
    border-radius:15px;
    box-shadow:0 5px 15px var(--shadow);
    transition:0.3s;
}

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

.education-card{
    max-width:400px;
    margin:auto;
}

footer{
    text-align:center;
    padding:25px;
    background:var(--card);
}

@media(max-width:768px){

    nav{
        flex-direction:column;
        gap:15px;
    }

    nav ul{
        flex-wrap:wrap;
        justify-content:center;
    }

    .hero{
        flex-direction:column;
        text-align:center;
    }

    .hero-text h1{
        font-size:32px;
    }

    .hero-image img{
        width:220px;
    }
}