* { box-sizing: border-box; }
body {
    margin: 0;
    padding: 0;
    font-family: 'Exo 2', Arial, sans-serif;
    background: #333;
    color: #eee;
}

.topbar {
    background: #222;
    padding: 15px 30px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.brand { display: flex; align-items: center; gap: 10px; }
.logo { width: 30px; height: 30px; }
.brand-name { font-weight: bold; font-size: 18px; }

.nav { display: flex; gap: 20px; }
.nav-link { color: #999; text-decoration: none; }
.nav-link:hover { color: #fff; }

.topbar-right { display: flex; gap: 15px; align-items: center; }
.icon { width: 20px; height: 20px; }
.metric { display: flex; gap: 5px; align-items: center; color: #999; }
.metric .num { color: #fff; font-weight: bold; }

.container { max-width: 1000px; margin: 30px auto; padding: 30px; }
.hero { display: flex; gap: 30px; justify-content: center; }
.preview { flex: 1; }
.preview img { width: 100%; border-radius: 5px; }

.caption { text-align: center; font-size: 20px; margin-top: 20px; }

.key-row { display: flex; gap: 15px; justify-content: center; margin-top: 20px; }
.key {
    background: #444;
    border: 1px solid #555;
    padding: 12px 20px;
    border-radius: 5px;
    cursor: pointer;
    font-weight: bold;
    transition: all 0.2s;
}
.key:hover { background: #555; }
.key.highlight { background: #f5c63b; color: #000; }

.hint { text-align: center; color: #999; margin-top: 15px; }

.content-section { margin: 40px 0; }
.content-section h1 { font-size: 36px; margin-bottom: 20px; }
.content-section p { line-height: 1.6; font-size: 16px; color: #aaa; }

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin: 30px 0;
}

.feature-card {
    background: #3a3a3a;
    padding: 25px;
    border-radius: 5px;
    border: 1px solid #444;
}
.feature-card:hover { background: #444; }
.feature-card h3 { margin: 0; color: #f5c63b; }
.feature-card p { margin: 10px 0 0 0; color: #aaa; }

@media (max-width: 800px) {
    .hero { flex-direction: column; }
    .topbar { flex-direction: column; gap: 10px; }
}