/* ══════════════════════════════════════════
   BLCKBX Learn Page — learn.css
   ══════════════════════════════════════════ */

.nav-active { color: var(--accent-light) !important; }

/* ── Hero ── */
.learn-hero {
    padding: 160px 40px 80px;
    text-align: center;
}

.learn-hero-inner {
    max-width: 720px;
    margin: 0 auto;
}

.learn-hero h1 {
    font-size: 48px;
    font-weight: 700;
    letter-spacing: -2.5px;
    color: var(--text-primary);
    margin-bottom: 20px;
    line-height: 1.1;
}

.learn-hero-sub {
    font-size: 18px;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ── MCP vs RMCP Comparison Banner ── */
.compare-banner {
    padding: 0 40px 80px;
}

.compare-banner-inner {
    max-width: var(--max-width);
    margin: 0 auto;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 20px;
    padding: 60px 48px;
    overflow: hidden;
}

.compare-header {
    text-align: center;
    margin-bottom: 48px;
}

.compare-header h2 {
    font-size: 36px;
    font-weight: 700;
    letter-spacing: -1.5px;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.compare-header p {
    font-size: 16px;
    color: var(--text-secondary);
}

.compare-grid {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    gap: 32px;
    align-items: start;
}

.compare-col {
    padding: 32px;
    border-radius: 16px;
}

.compare-mcp {
    background: var(--bg-card);
    border: 1px solid var(--border);
}

.compare-rmcp {
    background: var(--accent-dim);
    border: 1px solid var(--accent);
}

.compare-label {
    font-family: 'JetBrains Mono', monospace;
    font-size: 12px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1.5px;
    margin-bottom: 4px;
}

.compare-mcp .compare-label { color: var(--text-muted); }
.compare-rmcp .compare-label { color: var(--accent-light); }

.compare-title {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 4px;
}

.compare-tagline {
    font-size: 14px;
    margin-bottom: 24px;
}

.compare-mcp .compare-tagline { color: var(--text-muted); }
.compare-rmcp .compare-tagline { color: var(--accent-light); font-weight: 600; }

.compare-items {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.compare-item {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 13px;
    color: var(--text-secondary);
    line-height: 1.5;
}

.compare-item-missing {
    opacity: 0.5;
}

.compare-icon {
    min-width: 20px;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 11px;
    font-weight: 700;
}

.compare-icon.allow {
    background: var(--bg-secondary);
    border: 1px solid var(--border-light);
    color: var(--text-muted);
}

.compare-icon.deny {
    background: rgba(239, 68, 68, 0.15);
    color: #ef4444;
}

.compare-icon.secure {
    background: rgba(34, 197, 94, 0.15);
    color: #22c55e;
}

.compare-divider {
    display: flex;
    align-items: center;
    justify-content: center;
    padding-top: 80px;
}

.compare-vs {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: var(--bg-card);
    border: 2px solid var(--border-light);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 14px;
    font-weight: 700;
    color: var(--text-muted);
    letter-spacing: 1px;
}

.compare-bottom {
    text-align: center;
    margin-top: 40px;
    padding-top: 32px;
    border-top: 1px solid var(--border);
}

.compare-bottom p {
    font-size: 18px;
    font-weight: 600;
    color: var(--accent-light);
    letter-spacing: -0.3px;
}

/* ── Four Pillars ── */
.learn-pillars {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
    margin-top: 48px;
}

.pillar {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 32px 24px;
    text-align: center;
    transition: all 0.2s;
}

.pillar:hover {
    border-color: var(--accent);
    transform: translateY(-4px);
}

.pillar-icon {
    margin-bottom: 20px;
    line-height: 0;
}

.pillar h3 {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 12px;
}

.pillar p {
    font-size: 13px;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ── Timeline ── */
.learn-timeline {
    max-width: 680px;
    margin-top: 48px;
}

.timeline-item {
    display: flex;
    gap: 24px;
    padding-bottom: 40px;
    position: relative;
}

.timeline-item:not(:last-child)::after {
    content: '';
    position: absolute;
    left: 19px;
    top: 48px;
    bottom: 0;
    width: 2px;
    background: var(--border);
}

.timeline-item-accent::after {
    display: none;
}

.timeline-marker {
    width: 40px;
    height: 40px;
    min-width: 40px;
    border-radius: 50%;
    background: var(--bg-card);
    border: 2px solid var(--border-light);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 16px;
    font-weight: 700;
    color: var(--text-muted);
    z-index: 1;
}

.timeline-marker-accent {
    background: var(--accent);
    border-color: var(--accent);
    color: var(--white);
}

.timeline-content h3 {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.timeline-content p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ── Lifecycle ── */
.lifecycle {
    display: flex;
    align-items: flex-start;
    gap: 8px;
    margin-top: 48px;
    overflow-x: auto;
    padding-bottom: 20px;
}

.lifecycle-step {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 24px 20px;
    min-width: 160px;
    flex: 1;
    transition: all 0.2s;
}

.lifecycle-step:hover {
    border-color: var(--accent);
}

.lifecycle-num {
    font-family: 'JetBrains Mono', monospace;
    font-size: 28px;
    font-weight: 700;
    color: var(--accent-light);
    margin-bottom: 12px;
}

.lifecycle-step h3 {
    font-size: 16px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.lifecycle-step p {
    font-size: 12px;
    color: var(--text-secondary);
    line-height: 1.6;
}

.lifecycle-arrow {
    display: flex;
    align-items: center;
    color: var(--text-muted);
    font-size: 20px;
    padding-top: 40px;
    min-width: 20px;
}

/* ── Semantic Grid ── */
.semantic-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.semantic-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 28px;
    transition: all 0.2s;
}

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

.semantic-card h3 {
    font-size: 16px;
    font-weight: 600;
    color: var(--accent-light);
    margin-bottom: 8px;
}

.semantic-card p {
    font-size: 13px;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ── Agent Features ── */
.agent-features {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    margin-top: 48px;
}

.agent-feature {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 40px 28px;
    text-align: center;
    transition: all 0.2s;
}

.agent-feature:hover {
    border-color: var(--accent);
    transform: translateY(-4px);
}

.agent-num {
    font-size: 48px;
    font-weight: 700;
    color: var(--accent-light);
    margin-bottom: 8px;
    font-family: 'JetBrains Mono', monospace;
    letter-spacing: -2px;
}

.agent-feature h3 {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 12px;
}

.agent-feature p {
    font-size: 13px;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ── Responsive ── */
@media (max-width: 1024px) {
    .compare-grid { grid-template-columns: 1fr; gap: 24px; }
    .compare-divider { padding-top: 0; }
    .learn-pillars { grid-template-columns: repeat(2, 1fr); }
    .lifecycle { flex-direction: column; }
    .lifecycle-arrow { transform: rotate(90deg); padding: 0; margin: 0 auto; }
    .semantic-grid { grid-template-columns: repeat(2, 1fr); }
    .agent-features { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
    .learn-hero { padding: 120px 20px 60px; }
    .learn-hero h1 { font-size: 32px; }
    .compare-banner { padding: 0 20px 40px; }
    .compare-banner-inner { padding: 32px 20px; }
    .compare-header h2 { font-size: 28px; }
    .learn-pillars { grid-template-columns: 1fr; }
    .semantic-grid { grid-template-columns: 1fr; }
}