:root {
    --bg: #0b0b0c;
    --surface: #131315;
    --text-main: #f4f4f6;
    --text-muted: #8a8a93;
    --accent: #6366f1;
    --border: #222226;
    
    /* Fibonacci Spacing & Layout System */
    --f1: 8px;
    --f2: 13px;
    --f3: 21px;
    --f5: 34px;
    --f8: 55px;
    --f13: 89px;
    --f21: 144px;
}

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

body {
    background-color: var(--bg);
    color: var(--text-main);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

/* Pure Geometric Fibonacci Grid Layout */
.fibonacci-grid {
    display: grid;
    grid-template-columns: minmax(0, var(--f21)) minmax(0, 1fr);
    gap: var(--f5);
    max-width: 1200px;
    width: 100%;
    margin: 0 auto;
    padding: var(--f8) var(--f5);
    flex: 1;
}

/* Sidebar Pane (Fibonacci Width 1: 144px proportion) */
.panel-alpha {
    display: flex;
    flex-direction: column;
    gap: var(--f8);
}

.logo-mark {
    font-size: var(--f3);
    font-weight: 700;
    letter-spacing: -0.05em;
    color: var(--text-main);
    text-decoration: none;
    display: block;
}

.nav-links {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: var(--f2);
}

.nav-links a {
    color: var(--text-muted);
    text-decoration: none;
    font-size: 14px;
    font-weight: 500;
    transition: color 0.2s ease;
}

.nav-links a:hover {
    color: var(--text-main);
}

/* Main Display Pane (Fibonacci Width 2: Expanding Proportions) */
.panel-beta {
    display: flex;
    flex-direction: column;
    gap: var(--f13);
}

.hero-section h1 {
    font-size: var(--f5);
    font-weight: 600;
    letter-spacing: -0.03em;
    line-height: 1.2;
    max-width: 600px;
    margin-bottom: var(--f3);
}

.hero-section p {
    color: var(--text-muted);
    font-size: 16px;
    max-width: 520px;
}

/* Modular Category Grid mirroring Golden Proportions */
.brackets-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--f3);
}

.bracket-card {
    background: var(--surface);
    border: 1px solid var(--border);
    padding: var(--f5);
    border-radius: 4px;
    display: flex;
    flex-direction: column;
    gap: var(--f2);
}

.bracket-card h3 {
    font-size: 18px;
    font-weight: 600;
    letter-spacing: -0.01em;
}

.bracket-card p {
    color: var(--text-muted);
    font-size: 14px;
    line-height: 1.6;
}

.meta-spec {
    font-family: monospace;
    font-size: 12px;
    color: var(--accent);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-top: auto;
    padding-top: var(--f2);
}

footer {
    border-top: 1px solid var(--border);
    padding: var(--f5) 0;
    margin-top: var(--f13);
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--f5);
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 12px;
    color: var(--text-muted);
}

/* Clean responsiveness breaking back to single stack */
@media (max-width: 768px) {
    .fibonacci-grid {
        grid-template-columns: 1fr;
        gap: var(--f8);
        padding: var(--f5) var(--f3);
    }
    .panel-alpha {
        gap: var(--f3);
        flex-direction: row;
        justify-content: space-between;
        align-items: center;
        border-bottom: 1px solid var(--border);
        padding-bottom: var(--f3);
    }
    .nav-links {
        flex-direction: row;
        gap: var(--f3);
    }
    .panel-beta {
        gap: var(--f8);
    }
}