:root {
    --bg-primary: #0A0F1D;
    --bg-secondary: #161B2E;
    --text-primary: #F3F4F6;
    --text-secondary: #9CA3AF;
    --accent-red: #BE123C;
    --accent-red-hover: #9F1239;
    --border-color: #1F2937;
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

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

body {
    background-color: var(--bg-primary);
    color: var(--text-primary);
    font-family: var(--font-sans);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

header {
    border-bottom: 1px solid var(--border-color);
    padding: 1.5rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: rgba(10, 15, 29, 0.8);
    backdrop-filter: blur(8px);
    position: sticky;
    top: 0;
    z-index: 100;
}

.logo {
    font-size: 1.25rem;
    font-weight: 700;
    letter-spacing: -0.025em;
    color: var(--text-primary);
    text-decoration: none;
    display: flex;
    align-items: center;
}

.logo span {
    color: var(--accent-red);
    margin-right: 0.5rem;
}

nav ul {
    display: flex;
    list-style: none;
    gap: 2rem;
}

nav a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.875rem;
    font-weight: 500;
    transition: color 0.2s;
}

nav a:hover {
    color: var(--text-primary);
}

.btn-primary {
    background-color: var(--accent-red);
    color: white;
    padding: 0.625rem 1.25rem;
    border-radius: 4px;
    text-decoration: none;
    font-size: 0.875rem;
    font-weight: 600;
    transition: background-color 0.2s;
}

.btn-primary:hover {
    background-color: var(--accent-red-hover);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 4rem 2rem;
    display: grid;
    grid-template-columns: 250px 1fr;
    gap: 4rem;
}

.sidebar {
    position: sticky;
    top: 8rem;
    height: fit-content;
}

.sidebar h3 {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

.sidebar ul {
    list-style: none;
}

.sidebar li {
    margin-bottom: 0.75rem;
}

.sidebar a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9375rem;
    transition: color 0.2s;
}

.sidebar a:hover, .sidebar a.active {
    color: var(--accent-red);
}

.content h1 {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 1.5rem;
    letter-spacing: -0.025em;
}

.content p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    font-size: 1.125rem;
}

.content h2 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-top: 3rem;
    margin-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.5rem;
}

.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
    margin-top: 2rem;
}

.card {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    padding: 1.5rem;
    border-radius: 8px;
    transition: transform 0.2s, border-color 0.2s;
}

.card:hover {
    border-color: var(--accent-red);
}

.card h4 {
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.card p {
    font-size: 0.875rem;
    margin-bottom: 0;
}

.code-block {
    background-color: #010409;
    padding: 1.5rem;
    border-radius: 6px;
    font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
    font-size: 0.875rem;
    color: #e6edf3;
    overflow-x: auto;
    margin: 1.5rem 0;
    border: 1px solid var(--border-color);
}

footer {
    border-top: 1px solid var(--border-color);
    padding: 4rem 2rem;
    margin-top: 4rem;
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.875rem;
}

@media (max-width: 900px) {
    .container {
        grid-template-columns: 1fr;
    }
    .sidebar {
        display: none;
    }
}