:root {
    --bg-dark: #000000;
    --gray: #141313;
    --orange: #f97316;
    --text-light: #d4d4d4;
    --text-white: #ffffff;
}

body {
    margin: 0;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--bg-dark);
    color: var(--text-light);
    overflow-x: hidden;
}

header {
    background-color: #000000;
    color: white;
    padding: 2rem;
    text-align: center;
    background-image: url('/Home/Competitions/suas/blogs/images/pdb_head.png');
    background-repeat: no-repeat;
    background-size: 100% 100%;
}

body {
    color: white;
}

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

input,
textarea {
    font-size: 16px;
    color: white;
    margin-left: 10px;
}

img {
    margin: 10px 0px;
    width: 30vw;
}

.main {
    width: 70vw;
    margin: 0 auto;
}

section {
    padding: 2rem 0;
    background-color: var(--bg-dark);
}

.topic-box {
    background-color: var(--gray);
    padding: 2rem;
    margin-bottom: 2rem;
    border-radius: 10px;
    transition: transform 0.3s ease;
}

.topic-box h2 {
    color: var(--text-white);
    margin-top: 0;
}

.topic-box:hover {
    transform: scale(1.03);
}

.topic-box:hover h2,
.topic-box:hover p {
    color: var(--text-white);
}

.cards-container {
    display: flex;
    flex-wrap: wrap;
    gap: 1.5rem;
    margin-top: 1rem;
}

.card {
    background-color: rgb(29, 28, 28);
    flex: 1 1 calc(33.333% - 1rem);
    padding: 1.5rem;
    border-radius: 10px;
    transition: transform 0.3s ease, background-color 0.3s ease, color 0.3s ease;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
    color: var(--text-light);
}

.via-diagram {
    text-align: center;
    margin-top: 2rem;
}

.via-diagram img {
    max-width: 100%;
    border: 2px solid var(--orange);
    border-radius: 10px;
}

.via-diagram caption {
    margin-top: 0.5rem;
    color: var(--text-light);
    font-style: italic;
}

@media (max-width: 900px) {
    .card {
        flex: 1 1 100%;
    }

    .main {
        width: 90vw;
    }
}