html,
body {
    height: 100%;
    margin: 0;
    padding: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Arial, sans-serif;
    display: flex;
    flex-direction: column;
}

header {
    background: #222;
    color: #fff;
    padding: 1rem;
    display: flex;
    align-items: center;
    gap: 1.5rem;
    flex-wrap: wrap;
}

header h1 {
    margin: 0;
    font-size: 1.1rem;
    letter-spacing: 0.03em;
    white-space: nowrap;
}

header nav {
    display: flex;
    flex-wrap: wrap;
    gap: 0.15rem;
}

header nav a {
    color: #ccc;
    text-decoration: none;
    padding: 0.25rem 0.6rem;
    border-radius: 4px;
    font-size: 0.88rem;
    transition: color 0.15s, background 0.15s;
}

header nav a:hover {
    color: #fff;
    background: rgba(255, 255, 255, 0.08);
    text-decoration: none;
}

header nav a.nav-active {
    color: #fff;
    background: rgba(255, 255, 255, 0.13);
    font-weight: 600;
}

main {
    flex: 1;
    padding: 2rem;
    max-width: 1000px;
    width: 100%;
    box-sizing: border-box;
    margin: 0 auto;
}

ul {
    list-style-type: none;
    padding: 0;
}

.photo-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 1rem;
}

.photo-grid img {
    width: 100%;
    height: auto;
    border-radius: 4px;
    object-fit: cover;
}

footer {
    text-align: center;
    padding: 1rem;
    background: #222;
    color: #888;
    font-size: 0.82rem;
}

h1, h2, h3, h4, h5, h6 {
    margin: 0;
}