* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}
body {
    font-family: Arial, sans-serif;
    background: #101218;
    color: #f5f5f5;
    line-height: 1.6;
}
main {
    max-width: 850px;
    margin: auto;
    padding: 70px 25px;
}
.hero {
    padding: 70px 0;
}
.tag {
    color: #888;
    font-size: 13px;
    letter-spacing: 3px;
}
h1 {
    font-size: 70px;
    margin: 10px 0;
}
h2 {
    margin-bottom: 10px;
}
p {
    color: #aaa;
}
section {
    padding: 45px 0;
    border-top: 1px solid #292c33;
}
.cards {
    display: flex;
    gap: 15px;
    margin-top: 25px;
    flex-wrap: wrap;
}
.card {
    flex: 1;
    min-width: 200px;
    padding: 20px;
    background: #181b22;
    border: 1px solid #292c33;
    border-radius: 10px;
}
.card h3 {
    margin-bottom: 7px;
}
.demo {
    margin-top: 25px;
    padding: 20px;
    background: #090b0f;
    border-radius: 10px;
}
button {
    margin: 15px 5px 0 0;
    padding: 9px 13px;
    background: #181b22;
    color: white;
    border: 1px solid #3a3e48;
    border-radius: 6px;
    cursor: pointer;
}
button:hover {
    background: #252933;
}
#output {
    margin-top: 20px;
    min-height: 25px;
    color: #ddd;
    white-space: pre-line;
    font-family: monospace;
}
.tech {
    margin-top: 20px;
    color: #aaa;
}
footer {
    border-top: 1px solid #292c33;
    padding-top: 25px;
    display: flex;
    justify-content: space-between;
}
a {
    color: white;
}
@media (max-width: 600px) {
    h1 {
        font-size: 52px;
    }
    footer {
        display: block;
    }
}