:root {
    --bg: #111;
    --fg: #E0E0E0;
    --accent: #00FF00;
    /* Extended color scales */
    --bg-1: #111; /* base */
    --bg-2: #141414; /* slightly lighter for stripes */
    --bg-3: #1a1a1a; /* hover surface */
    --accent-600: #00FF00; /* primary */
    --accent-500: #00E600; /* hover */
    --accent-400: #00CC00; /* active/focus */
    /* UI tokens */
    --radius: 8px;
    --shadow: 0 6px 16px rgba(0,0,0,.25);
    accent-color: var(--accent);
}

/* Global Styling */
body {
    margin: 0;
    font-family: 'Montserrat', sans-serif;
    background-color: var(--bg);
    color: var(--fg);
    line-height: 1.65;
}
h1, h2, h3, h4, h5, h6 {
    font-family: 'VT323', monospace;
    color: var(--fg);
}
a, .btn, .nav-link {
    transition: color .18s ease-out, background-color .18s ease-out, border-color .18s ease-out, box-shadow .18s ease-out, transform .18s ease-out;
}
a {
    color: var(--accent);
    text-decoration: none;
}
a:hover {
    color: var(--accent-400);
    text-decoration: underline;
    text-decoration-thickness: 2px;
    text-underline-offset: 2px;
}

/* Primary button theme override */
.btn-primary{
    --bs-btn-bg: var(--accent);
    --bs-btn-border-color: var(--accent);
    --bs-btn-hover-bg: var(--accent-400);
    --bs-btn-hover-border-color: var(--accent-400);
    --bs-btn-color: #000;
}
.btn, .form-control {
    border-radius: var(--radius);
}
.btn:hover { box-shadow: 0 4px 12px rgba(0,0,0,.25); }

/* Navbar */
nav.navbar {
    background: var(--bg);
    position: sticky;
    top: 0;
    z-index: 1030;
    border-bottom: 1px solid #222;
    box-shadow: 0 2px 10px rgba(0,0,0,.25);
}
nav .navbar-brand, nav .nav-link {
    color: var(--fg) !important;
}
nav .nav-link:hover {
    color: var(--accent) !important;
}
.navbar .nav-link.active {
    color: var(--accent) !important;
    border-bottom: 2px solid var(--accent);
}
.navbar-toggler-icon {
    filter: brightness(0) invert(1);
}

/* Hero Section */
.hero {
    min-height: 80vh;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    text-align: center;
    padding: 60px 20px;
    background: var(--bg);
    color: var(--fg);
    position: relative;
    overflow: hidden;
}
.hero::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(
      circle at center,
      rgba(0, 255, 0, 0.1) 0%,
      transparent 70%
    );
    z-index: 1;
}
.hero-content {
    position: relative;
    z-index: 2;
    max-width: 700px;
}
.hero-avatars {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 12px;
    margin-bottom: 12px;
}
@media (min-width: 576px) {
    .hero-avatars { flex-direction: row; }
}
.hero img {
    width: 140px;
    height: 140px;
    object-fit: cover;
    border-radius: 50%;
    margin-bottom: 20px;
    border: 3px solid var(--accent);
    box-shadow: 0 6px 10px rgba(0, 0, 0, 0.15);
}
.hero h1 { font-size: clamp(2rem, 1.4rem + 2.5vw, 3rem); }
.hero h1 {
    margin-bottom: 10px;
    font-weight: 600;
    letter-spacing: 1px;
}
.hero p {
    font-size: 1.1rem;
    margin-bottom: 30px;
    line-height: 1.6;
}
.hero-content p { max-width: 72ch; margin-left: auto; margin-right: auto; }
.cta-group { display: inline-flex; gap: 12px; align-items: center; }

/* Portfolio Section */
.portfolio {
    padding: 60px 20px;
    background-color: var(--bg);
}
.portfolio h2 {
    text-align: center;
    margin-bottom: 40px;
    font-size: clamp(1.5rem, 1.1rem + 1.2vw, 2rem);
    font-weight: 600;
    color: var(--fg);
}
.table-responsive {
    display: flex;
    justify-content: center;
}
.table {
    width: 100%;
    border: 1px solid var(--accent);
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow);
}
.table th, .table td {
    color: var(--fg);
    border: 1px solid var(--accent);
    vertical-align: middle;
}
.table thead th {
    background-color: var(--accent);
    color: #000000;
    position: sticky;
    top: 0;
    z-index: 1;
}
.table-striped>tbody>tr:nth-of-type(odd) {
    background-color: var(--bg-2);
}
.table-hover tbody tr:hover {
    background-color: var(--bg-3);
}
.report-link {
    color: var(--accent);
    text-decoration: none;
}
.report-link:hover {
    text-decoration: underline;
}
/* Anchor offset for sticky navbar */
#hero, #portfolio, #contests { scroll-margin-top: 80px; }
@media (max-width: 576px) {
    .table th, .table td { padding: .5rem; }
}

/* Footer */
.footer {
    background-color: var(--bg);
    color: var(--fg);
    text-align: center;
    padding: 20px 0;
}
.footer p {
    margin: 0;
    font-size: 0.9rem;
}

/* Accessibility: visible keyboard focus */
a:focus-visible, button:focus-visible, .btn:focus-visible, .nav-link:focus-visible {
    outline: 2px dashed var(--accent);
    outline-offset: 2px;
}

/* Skip link utility */
.visually-hidden-focusable {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}
.visually-hidden-focusable:focus,
.visually-hidden-focusable:active {
    position: static;
    width: auto;
    height: auto;
    margin: 0;
    clip: auto;
    white-space: normal;
    background: #222;
    color: var(--fg);
    padding: 8px 12px;
}

/* Reduced motion preference */
@media (prefers-reduced-motion: reduce) {
    * {
        animation: none !important;
        transition: none !important;
        scroll-behavior: auto !important;
    }
}

/* Selection color */
::selection {
    background: var(--accent);
    color: #000;
}