* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: 'Segoe UI', sans-serif;
    background: #f5f5f5;
    color: #333;
}

/* HEADER */
.header {
    position: relative;
    max-width: 900px;
    margin: auto;
    height: 300px;
    overflow: hidden;
    box-shadow: 0 4px 16px rgba(0,0,0,0.6);
}

.header-video {
    position: absolute;
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.overlay {
    position: absolute;
    inset: 0;
    background: rgba(0,0,0,0.4);
    z-index: 1;
}

@keyframes vid1 { 0%,40%{opacity:1;} 43%,100%{opacity:0;} }
@keyframes vid2 { 0%,40%{opacity:0;} 43%,100%{opacity:1;} }

.header-content {
    position: relative;
    z-index: 2;
    text-align: center;
    padding-top: 80px;
    color: #fff;
    text-shadow: 2px 2px 4px #000;
}

.header-content ul {
    list-style: none;
    padding: 0;
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
}

.header-content li {
    margin: 0 15px 20px;
}

.header-content a {
    color: #fff;
    text-decoration: none;
    font-weight: bold;
}

#selected {
    color: #ffa500;
}

/* CONTENT */
.bg-content,
.bg-content1 {
    max-width: 900px;
    margin: auto;
    padding: 2rem;
    box-shadow: 0 4px 16px rgba(0,0,0,0.4);
}

.download-buttons button {
    padding: 10px 20px;
    margin: 5px;
    background: #202020;
    color: #fff;
    border: none;
    border-radius: 6px;
    cursor: pointer;
}

.download-buttons button:hover {
    background: #444;
}

blockquote {
    background: #eee;
    border-left: 4px solid #444;
    padding: 8px;
    font-style: italic;
}

/* MOBILE */
@media (max-width: 600px) {
    .header {
        height: 200px;
    }
    .header-content h1 {
        font-size: 24px;
    }
}