* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'JetBrains Mono', 'Hack', 'Cascadia Code', monospace;
    color: #ffffff;
    line-height: 1.6;
    background-repeat: no-repeat;
    background-position: center center;
    background-attachment: fixed;
    background-size: cover;
    background-color: #000;
    animation: changeBg 20s infinite;
    transition: background-image 1s ease-in-out;
}

@keyframes changeBg {
    0%, 25%, 100% { background-image: url('/img/background_0.webp'); }
    33%, 58%     { background-image: url('/img/background_1.webp'); }
    66%, 92%     { background-image: url('/img/background_2.webp'); }
}

header {
    background: rgba(0, 0, 0, 0.35); 
    backdrop-filter: blur(15px);
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.5rem 5%;
    z-index: 1000;
}

header img {
    height: 80px;
}

main {
    text-align: center;
    padding: 80px 10%;
    background: rgba(0, 0, 0, 0.35); 
    backdrop-filter: blur(10px);
    margin: 40px 5%;
    border-radius: 15px;
    color: #ffffff;
}

main h1 {
    font-size: 2.8rem;
    margin-bottom: 20px;
    color: #0088cc;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.35);
}

section {
    padding: 60px 5%;
}

section h2 {
    text-align: center;
    margin-bottom: 40px;
    text-transform: uppercase;
    color: #0088cc;
    text-shadow: 1px 1px 3px rgba(0, 0, 0, 0.35);
    font-size: 30px;
}

section div { 
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 25px;
    align-items: start;
}

article {
    background: rgba(0, 0, 0, 0.35);
    border: 3px solid rgba(0, 0, 0, 0);
    backdrop-filter: blur(8px);
    padding: 20px;
    border-radius: 15px;
    transition: all 0.3s ease;
    text-align: center;
}

article:hover {
    transform: translateY(-10px);
    border: 3px solid rgba(0, 136, 204, 1);
    background: rgba(0, 0, 0, 0.45);
}

article h3 {
    margin-bottom: 15px;
    color: #0088cc;
}

footer {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 40px;
    padding: 60px 10%;
    background: rgba(0, 0, 0, 0.35); 
    backdrop-filter: blur(12px);
    color: #ffffff;
    font-size: 1rem;
}

footer div {
    flex: 1;
    min-width: 250px;
    max-width: 380px;
}

footer strong {
    display: block;
    color: #0088cc;
    margin-bottom: 8px;
    text-transform: uppercase;
}

footer a {
    color: inherit;
    text-decoration: none;
}

footer a:hover { 
    color: #00ffff; 
}

@media (max-width: 1024px) {
    section div { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 600px) {
    section div { grid-template-columns: 1fr; }
    footer { flex-direction: column; text-align: center; }
    .copyright { margin-top: 30px; }
    main { padding: 40px 5%; }
    header { flex-direction: column; gap: 15px; }
}

.copyright {
    flex-basis: 100%;
    text-align: center;
    margin-top: 50px;
    font-size: 0.8rem;
    opacity: 0.6;
    order: 99;
}

header nav a, 
header nav a:link, 
header nav a:visited {
    color: #ffffff;
    text-decoration: none;
    opacity: 0.5;
    font-size: 1rem;
    transition: all 0.3s ease;
}

header nav a:hover {
    color: #0088cc;
    opacity: 1;
}

header nav a.active {
    color: #0088cc;
    opacity: 1;
    pointer-events: none;
}