:root {
    color-scheme: dark;
    --bg: #111827;
    --panel: #1f2937;
    --panel-soft: #243244;
    --text: #f9fafb;
    --muted: #9ca3af;
    --accent: #2563eb;
    --accent-soft: #1d4ed8;
    --border: #374151;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
}

.site-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 16px;
    padding: 16px 24px;
    border-bottom: 1px solid var(--border);
}

.brand,
.nav-link,
.button-link {
    color: var(--text);
    text-decoration: none;
}

.main-nav {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.nav-link,
.button-link,
.tab-button {
    border: 1px solid var(--border);
    background: var(--panel-soft);
    padding: 10px 14px;
    border-radius: 10px;
    cursor: pointer;
}

.nav-link.active,
.button-link,
.tab-button.active {
    background: var(--accent);
    border-color: var(--accent-soft);
}

.button-link.secondary {
    background: transparent;
}

.page-container {
    max-width: 960px;
    margin: 0 auto;
    padding: 24px;
}

.hero-card,
.module-card,
.trainer-card {
    background: var(--panel);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 24px;
}

.module-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 16px;
    margin-top: 16px;
}

.hidden {
    display: none !important;
}