/* ============================================
   BBC Micro Machine Hub — Stylesheet
   Theme-aware (dark/light), responsive, a11y
   Mirrors C64/Amiga hub patterns with bbc- prefix
   ============================================ */

/* --- Quick-Jump Navigation Strip --- */
.bbc-quicknav {
    padding: 1.5rem 0;
}

.bbc-quicknav-strip {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 0.5rem;
    padding: 0.85rem;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius);
}

.bbc-quicknav-label {
    display: inline-flex;
    align-items: center;
    padding: 0 0.5rem 0 0.35rem;
    font-family: var(--font-heading);
    font-size: 0.7rem;
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--text-muted);
}

.bbc-qn-link {
    display: inline-flex;
    align-items: center;
    padding: 0.45rem 0.9rem;
    font-family: var(--font-heading);
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--text-secondary);
    background: var(--bg-card-solid);
    border: 1px solid var(--border);
    border-radius: 999px;
    transition: all var(--transition);
    white-space: nowrap;
    text-decoration: none;
}

.bbc-qn-link:hover {
    color: var(--accent);
    background: var(--accent-glow);
    border-color: var(--border-hover);
}

.bbc-qn-link--danger {
    color: var(--error);
    border-color: rgba(255, 68, 102, 0.2);
}

.bbc-qn-link--danger:hover {
    color: #fff;
    background: var(--error);
    border-color: var(--error);
}

/* --- RIFA Warning Section --- */
.bbc-rifa-section {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
}

.bbc-rifa-warning {
    border-color: rgba(255, 68, 102, 0.3);
    position: relative;
}

.bbc-rifa-warning::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--error), #ff8844, var(--error));
    border-radius: var(--radius-lg) var(--radius-lg) 0 0;
    opacity: 0.8;
}

.bbc-rifa-warning-header {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1rem;
}

.bbc-rifa-icon {
    color: var(--error);
    flex-shrink: 0;
    filter: drop-shadow(0 0 6px rgba(255, 68, 102, 0.4));
}

.bbc-rifa-warning-header h2 {
    font-family: var(--font-heading);
    font-size: 1.35rem;
    color: var(--error);
    margin: 0;
}

.bbc-rifa-lead {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 1.5rem;
}

.bbc-rifa-lead strong {
    color: var(--error);
}

.bbc-rifa-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.25rem;
}

.bbc-rifa-identify h3,
.bbc-rifa-replace h3,
.bbc-rifa-context h3 {
    font-family: var(--font-heading);
    font-size: 1rem;
    color: var(--text-primary);
    margin-bottom: 0.75rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.bbc-step-num {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 1.75rem;
    height: 1.75rem;
    background: var(--error);
    color: #fff;
    border-radius: 50%;
    font-size: 0.82rem;
    font-weight: 700;
    flex-shrink: 0;
}

.bbc-rifa-steps {
    list-style: none;
    padding: 0;
    margin: 0;
}

.bbc-rifa-steps li {
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.6;
    padding: 0.35rem 0;
    padding-left: 1rem;
    position: relative;
    border-bottom: 1px solid var(--border);
}

.bbc-rifa-steps li:last-child {
    border-bottom: none;
}

.bbc-rifa-steps li::before {
    content: '\2022';
    position: absolute;
    left: 0;
    color: var(--error);
    font-weight: 700;
}

/* --- Model Selector Tabs --- */
.bbc-model-tabs {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 2rem;
    padding: 0.85rem;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius);
}

.bbc-model-tab {
    display: inline-flex;
    align-items: center;
    padding: 0.6rem 1.2rem;
    font-family: var(--font-heading);
    font-size: 0.88rem;
    font-weight: 600;
    color: var(--text-secondary);
    background: var(--bg-card-solid);
    border: 1px solid var(--border);
    border-radius: 999px;
    cursor: pointer;
    transition: all var(--transition);
    white-space: nowrap;
}

.bbc-model-tab:hover {
    color: var(--accent);
    background: var(--accent-glow);
    border-color: var(--border-hover);
}

.bbc-model-tab.active {
    color: var(--accent);
    background: var(--accent-glow);
    border-color: var(--accent);
    cursor: default;
}

/* --- Model Panels --- */
.bbc-model-panel {
    display: none;
    animation: bbcFadeIn 0.35s ease;
}

.bbc-model-panel.active {
    display: block;
}

@keyframes bbcFadeIn {
    from { opacity: 0; transform: translateY(12px); }
    to   { opacity: 1; transform: translateY(0); }
}

.bbc-model-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
}

.bbc-model-info h3 {
    font-family: var(--font-heading);
    font-size: 1.15rem;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

.bbc-badge {
    display: inline-block;
    font-size: 0.68rem;
    font-weight: 600;
    padding: 0.2rem 0.55rem;
    background: var(--accent-glow);
    color: var(--accent);
    border: 1px solid var(--border-hover);
    border-radius: 999px;
    vertical-align: middle;
    margin-left: 0.35rem;
    letter-spacing: 0.02em;
}

.bbc-model-info p {
    color: var(--text-secondary);
    font-size: 0.92rem;
    line-height: 1.65;
    margin-bottom: 1rem;
}

.bbc-model-info h4,
.bbc-model-notes h4 {
    font-family: var(--font-heading);
    font-size: 0.82rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--accent);
    margin-bottom: 0.6rem;
}

.bbc-ic-list {
    list-style: none;
    padding: 0;
}

.bbc-ic-list li {
    font-size: 0.88rem;
    color: var(--text-secondary);
    padding: 0.3rem 0;
    border-bottom: 1px solid var(--border);
}

.bbc-ic-list li:last-child {
    border-bottom: none;
}

.bbc-ic-list li strong {
    color: var(--text-primary);
    font-weight: 600;
    min-width: 7rem;
    display: inline-block;
}

/* --- Shared Table Style --- */
.bbc-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.85rem;
}

.bbc-table thead th {
    font-family: var(--font-heading);
    font-size: 0.72rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--text-muted);
    padding: 0.55rem 0.75rem;
    border-bottom: 2px solid var(--border);
    text-align: left;
}

.bbc-table tbody td {
    padding: 0.5rem 0.75rem;
    color: var(--text-secondary);
    border-bottom: 1px solid var(--border);
}

.bbc-table tbody tr:hover td {
    background: var(--accent-glow);
    color: var(--text-primary);
}

.bbc-table--compact {
    font-size: 0.82rem;
}

.bbc-table--compact thead th {
    padding: 0.4rem 0.6rem;
}

.bbc-table--compact tbody td {
    padding: 0.35rem 0.6rem;
}

.bbc-note {
    font-size: 0.82rem;
    color: var(--text-muted);
    margin-top: 1rem;
    padding: 0.75rem;
    background: var(--bg-secondary);
    border-left: 3px solid var(--accent);
    border-radius: 0 var(--radius) var(--radius) 0;
    line-height: 1.55;
}

.bbc-note strong {
    color: var(--accent);
}

.bbc-note a {
    color: var(--accent);
}

.bbc-note a:hover {
    color: var(--accent-hover);
}

/* --- EPROM Guide Grid --- */
.bbc-eprom-section {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
}

.bbc-eprom-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
}

.bbc-eprom-card h3 {
    font-family: var(--font-heading);
    font-size: 1rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.bbc-eprom-card > p {
    font-size: 0.88rem;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 1rem;
}

/* --- Video & Display Grid --- */
.bbc-video-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
}

.bbc-video-card h3 {
    font-family: var(--font-heading);
    font-size: 1rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.bbc-video-card > p {
    font-size: 0.88rem;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 1rem;
}

.bbc-converter-list {
    list-style: none;
    padding: 0;
}

.bbc-converter-list li {
    padding: 0.65rem 0;
    border-bottom: 1px solid var(--border);
}

.bbc-converter-list li:last-child {
    border-bottom: none;
}

.bbc-converter-list li strong {
    display: block;
    color: var(--text-primary);
    font-size: 0.9rem;
    margin-bottom: 0.15rem;
}

.bbc-converter-list li span {
    display: block;
    color: var(--text-muted);
    font-size: 0.82rem;
    line-height: 1.5;
}

/* --- Diagnostic Checklist Grid --- */
.bbc-diag-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
}

.bbc-diag-card[data-fault="ic-faults"] {
    grid-column: 1 / -1;
}

.bbc-diag-card {
    transition: transform var(--transition), box-shadow var(--transition);
}

.bbc-diag-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.bbc-diag-header {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    margin-bottom: 0.75rem;
}

.bbc-diag-icon {
    font-size: 1.4rem;
    color: var(--warning);
    line-height: 1;
}

.bbc-diag-icon--port {
    color: var(--accent);
}

.bbc-diag-icon--chip {
    color: var(--error);
}

.bbc-diag-header h3 {
    font-family: var(--font-heading);
    font-size: 1.05rem;
    color: var(--text-primary);
    margin: 0;
}

.bbc-diag-symptom {
    font-size: 0.88rem;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 1rem;
    padding: 0.6rem 0.75rem;
    background: var(--bg-secondary);
    border-left: 3px solid var(--warning);
    border-radius: 0 6px 6px 0;
}

.bbc-diag-card h4 {
    font-family: var(--font-heading);
    font-size: 0.82rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--accent);
    margin-bottom: 0.5rem;
}

.bbc-diag-steps {
    padding-left: 1.2rem;
    margin: 0;
}

.bbc-diag-steps li {
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.6;
    padding: 0.3rem 0;
}

.bbc-diag-steps li::marker {
    color: var(--accent);
    font-weight: 700;
}

/* Econet / User Port dual-column */
.bbc-port-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.25rem;
    margin-top: 0.5rem;
}

.bbc-port-col h4 {
    font-family: var(--font-heading);
    font-size: 0.82rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    padding-bottom: 0.35rem;
    border-bottom: 2px solid var(--border);
}

.bbc-port-symptoms {
    list-style: none;
    padding: 0;
}

.bbc-port-symptoms li {
    font-size: 0.84rem;
    color: var(--text-secondary);
    padding: 0.35rem 0;
    padding-left: 1rem;
    position: relative;
    border-bottom: 1px solid var(--border);
}

.bbc-port-symptoms li:last-child {
    border-bottom: none;
}

.bbc-port-symptoms li::before {
    content: '\2022';
    position: absolute;
    left: 0;
    color: var(--accent);
    font-weight: 700;
}

/* --- IC Pinout Card Grid --- */
.bbc-ic-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.25rem;
}

.bbc-ic-card {
    display: flex;
    flex-direction: column;
    text-decoration: none;
    transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
    cursor: pointer;
}

.bbc-ic-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-lg);
    border-color: var(--border-hover);
}

.bbc-ic-card-chip {
    display: flex;
    justify-content: center;
    margin-bottom: 0.75rem;
}

.bbc-ic-card-pkg {
    display: inline-block;
    font-family: var(--font-mono);
    font-size: 0.68rem;
    font-weight: 500;
    padding: 0.2rem 0.5rem;
    background: var(--bg-secondary);
    color: var(--text-muted);
    border: 1px solid var(--border);
    border-radius: 4px;
    letter-spacing: 0.04em;
}

.bbc-ic-card h3 {
    font-family: var(--font-heading);
    font-size: 0.95rem;
    color: var(--text-primary);
    margin-bottom: 0.4rem;
}

.bbc-ic-card p {
    font-size: 0.8rem;
    color: var(--text-muted);
    line-height: 1.5;
    flex-grow: 1;
    margin-bottom: 0.75rem;
}

.bbc-ic-card-cta {
    font-family: var(--font-heading);
    font-size: 0.78rem;
    font-weight: 600;
    color: var(--accent);
    transition: color var(--transition);
}

.bbc-ic-card:hover .bbc-ic-card-cta {
    color: var(--accent-hover);
}

.bbc-ic-card:hover h3 {
    color: var(--accent);
}

/* --- Connector Pinout Grid --- */
.bbc-port-pinout-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
}

.bbc-port-card h3 {
    font-family: var(--font-heading);
    font-size: 1rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.bbc-port-card > p {
    font-size: 0.88rem;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 1rem;
}

/* --- Resources Grid --- */
.bbc-resources-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
}

.bbc-resource-group h3 {
    font-family: var(--font-heading);
    font-size: 1rem;
    color: var(--text-primary);
    margin-bottom: 0.75rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--border);
}

.bbc-resource-links {
    list-style: none;
    padding: 0;
}

.bbc-resource-links li {
    padding: 0.45rem 0;
    font-size: 0.88rem;
    border-bottom: 1px solid var(--border);
}

.bbc-resource-links li:last-child {
    border-bottom: none;
}

.bbc-resource-links a {
    color: var(--accent);
    text-decoration: none;
    transition: color var(--transition);
}

.bbc-resource-links a:hover {
    color: var(--accent-hover);
}

/* --- Responsive --- */
@media (max-width: 1024px) {
    .bbc-rifa-grid,
    .bbc-video-grid,
    .bbc-eprom-grid,
    .bbc-port-pinout-grid {
        grid-template-columns: 1fr 1fr;
    }

    .bbc-rifa-grid > :last-child,
    .bbc-eprom-grid > :last-child {
        grid-column: 1 / -1;
    }

    .bbc-ic-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (max-width: 768px) {
    .bbc-model-grid,
    .bbc-port-grid {
        grid-template-columns: 1fr;
    }

    .bbc-diag-grid {
        grid-template-columns: 1fr;
    }

    .bbc-diag-card[data-fault="ic-faults"] {
        grid-column: auto;
    }

    .bbc-rifa-grid,
    .bbc-video-grid,
    .bbc-eprom-grid,
    .bbc-port-pinout-grid,
    .bbc-resources-grid,
    .bbc-ic-grid {
        grid-template-columns: 1fr;
    }

    .bbc-rifa-grid > :last-child,
    .bbc-eprom-grid > :last-child {
        grid-column: auto;
    }

    .bbc-quicknav-strip {
        gap: 0.35rem;
        padding: 0.65rem;
    }

    .bbc-qn-link {
        font-size: 0.75rem;
        padding: 0.35rem 0.7rem;
    }

    .bbc-model-tab {
        font-size: 0.78rem;
        padding: 0.45rem 0.85rem;
    }
}

@media (max-width: 480px) {
    .bbc-table {
        font-size: 0.78rem;
    }

    .bbc-table thead th,
    .bbc-table tbody td {
        padding: 0.35rem 0.5rem;
    }
}