/* Bloor Engineering - Furnace Design Tool */
/* Professional dark theme with Bloor blue accent */

:root {
    --bg-primary: #1a1d23;
    --bg-secondary: #22262e;
    --bg-card: #2a2f38;
    --bg-input: #1e2128;
    --border: #3a4050;
    --border-light: #4a5060;
    --text-primary: #e8eaf0;
    --text-secondary: #a0a8b8;
    --text-muted: #6b7280;
    --accent: #1498d5;
    --accent-hover: #1181b5;
    --accent-dim: #0c2435;
    --success: #22c55e;
    --warning: #f59e0b;
    --danger: #ef4444;
    --hot: #ef4444;
    --cold: #1498d5;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
}

/* Top Bar */
.top-bar {
    display: flex;
    align-items: center;
    padding: 0 20px;
    height: 56px;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    gap: 24px;
}

.brand {
    display: flex;
    align-items: center;
    flex-shrink: 0;
}

.brand-img {
    height: 36px;
    width: auto;
    max-width: 160px;
    /* Dark theme: invert black→white, hue-rotate to restore brand blue */
    filter: invert(1) hue-rotate(180deg);
}

.light-theme .brand-img {
    filter: none;
}

.nav-links {
    display: flex;
    gap: 4px;
    margin-left: 20px;
}

.nav-links a {
    padding: 6px 14px;
    border-radius: 6px;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 13px;
    font-weight: 500;
    transition: all 0.15s;
}

.nav-links a:hover { background: var(--bg-card); color: var(--text-primary); }
.nav-links a.active { background: var(--accent-dim); color: var(--accent); }

/* Nav dropdown */
.nav-dropdown {
    position: relative;
}

.nav-dropdown-btn {
    padding: 6px 14px;
    border-radius: 6px;
    color: var(--text-secondary);
    font-size: 13px;
    font-weight: 500;
    background: none;
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 4px;
    transition: all 0.15s;
}

.nav-dropdown-btn:hover { background: var(--bg-card); color: var(--text-primary); }
.nav-dropdown-btn.active { background: var(--accent-dim); color: var(--accent); }

.nav-dropdown-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    margin-top: 4px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 6px;
    min-width: 180px;
    z-index: 50;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
}

.nav-dropdown:hover .nav-dropdown-menu { display: block; }

.nav-dropdown-menu a {
    display: block;
    padding: 6px 12px;
    border-radius: 4px;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 12px;
    font-weight: 500;
    transition: all 0.15s;
}

.nav-dropdown-menu a:hover { background: var(--bg-secondary); color: var(--text-primary); }
.nav-dropdown-menu a.active { color: var(--accent); }

/* Mobile nav toggle */
.nav-toggle {
    display: none;
    background: none;
    border: 1px solid var(--border);
    border-radius: 6px;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 4px 8px;
}

.header-actions {
    margin-left: auto;
    display: flex;
    gap: 8px;
}

/* Main Content */
.content {
    padding: 16px;
    max-width: 1600px;
    margin: 0 auto;
}

/* Calculator Layout */
.calc-layout {
    display: grid;
    grid-template-columns: 280px 1fr 380px;
    gap: 16px;
    min-height: calc(100vh - 88px);
}

/* Cards */
.card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 8px;
    overflow: hidden;
}

.card-header {
    padding: 12px 16px;
    border-bottom: 1px solid var(--border);
    font-weight: 600;
    font-size: 13px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    color: var(--text-primary);
}

.card-body {
    padding: 16px;
}

/* Form Controls */
.form-group {
    margin-bottom: 12px;
}

.form-group label {
    display: block;
    font-size: 11px;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 4px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.form-group input,
.form-group select {
    width: 100%;
    padding: 7px 10px;
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: 5px;
    color: var(--text-primary);
    font-size: 13px;
    outline: none;
    transition: border-color 0.15s;
}

.form-group input:focus,
.form-group select:focus {
    border-color: var(--accent);
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
}

/* Buttons */
.btn {
    padding: 7px 14px;
    border-radius: 6px;
    border: 1px solid var(--border);
    background: var(--bg-card);
    color: var(--text-primary);
    font-size: 12px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.15s;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

.btn:hover { background: var(--bg-secondary); border-color: var(--border-light); }

.btn-primary {
    background: var(--accent);
    border-color: var(--accent);
    color: white;
}

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

.btn-danger { color: var(--danger); }
.btn-danger:hover { background: rgba(239, 68, 68, 0.1); }

.btn-success { color: var(--success); }

.btn-sm { padding: 4px 8px; font-size: 11px; }

.btn-block { width: 100%; justify-content: center; }

.btn-calculate {
    width: 100%;
    padding: 10px;
    font-size: 14px;
    font-weight: 600;
    margin-top: 8px;
}

/* Zone Tabs */
.zone-tabs {
    display: flex;
    border-bottom: 1px solid var(--border);
}

.zone-tab {
    padding: 10px 20px;
    font-size: 13px;
    font-weight: 500;
    color: var(--text-secondary);
    cursor: pointer;
    border-bottom: 2px solid transparent;
    transition: all 0.15s;
    background: none;
    border-top: none;
    border-left: none;
    border-right: none;
}

.zone-tab:hover { color: var(--text-primary); }
.zone-tab.active {
    color: var(--accent);
    border-bottom-color: var(--accent);
}

/* Layer List */
.layer-list {
    padding: 12px;
}

.layer-num {
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: var(--accent-dim);
    color: var(--accent);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 11px;
    font-weight: 700;
}

.layer-remove {
    width: 24px;
    height: 24px;
    border: none;
    background: none;
    color: var(--text-muted);
    cursor: pointer;
    border-radius: 4px;
    font-size: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.layer-remove:hover { color: var(--danger); background: rgba(239, 68, 68, 0.1); }

.add-layer-btn {
    width: 100%;
    padding: 8px;
    margin-top: 4px;
    background: var(--bg-input);
    border: 1px dashed var(--border);
    border-radius: 6px;
    color: var(--text-secondary);
    cursor: pointer;
    font-size: 12px;
    transition: all 0.15s;
}

.add-layer-btn:hover {
    border-color: var(--accent);
    color: var(--accent);
}

/* Results Panel */
.results-panel {
    overflow-y: auto;
    max-height: calc(100vh - 88px);
}

.result-zone {
    margin-bottom: 16px;
}

.result-zone-header {
    padding: 8px 16px;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    font-weight: 600;
    font-size: 13px;
    display: flex;
    justify-content: space-between;
}

.result-stats {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
    padding: 12px 16px;
}

.stat-box {
    padding: 8px 10px;
    background: var(--bg-secondary);
    border-radius: 6px;
    border: 1px solid var(--border);
}

.stat-label {
    font-size: 10px;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 2px;
}

.stat-value {
    font-size: 16px;
    font-weight: 700;
    font-family: 'Consolas', 'Courier New', monospace;
}

.stat-value.hot { color: var(--hot); }
.stat-value.cold { color: var(--cold); }
.stat-value.neutral { color: var(--text-primary); }
.stat-value.success { color: var(--success); }
.stat-value.warning { color: var(--warning); }

/* Layer results table */
.result-layers-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 11px;
    margin: 0 0 8px;
}

.result-layers-table th {
    background: var(--bg-secondary);
    padding: 6px 10px;
    text-align: left;
    font-weight: 600;
    color: var(--text-secondary);
    font-size: 10px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    border-bottom: 1px solid var(--border);
}

.result-layers-table td {
    padding: 5px 10px;
    border-bottom: 1px solid var(--border);
    font-family: 'Consolas', 'Courier New', monospace;
}

.result-layers-table tr:last-child td { border-bottom: none; }

/* Total summary */
.total-summary {
    margin-top: 16px;
}

.total-summary .card-header {
    background: var(--accent-dim);
    color: var(--accent);
}

.total-row {
    display: flex;
    justify-content: space-between;
    padding: 8px 16px;
    border-bottom: 1px solid var(--border);
    font-size: 13px;
}

.total-row:last-child { border-bottom: none; }
.total-row .zone-name { color: var(--text-secondary); }
.total-row .zone-loss { font-family: 'Consolas', monospace; font-weight: 600; }

.total-row.grand-total {
    background: var(--bg-secondary);
    font-weight: 700;
    font-size: 15px;
}

.total-row.grand-total .zone-loss { color: var(--accent); }

/* Chart container */
.chart-container {
    padding: 12px 16px;
    height: 180px;
}

/* Status badge */
.badge {
    display: inline-block;
    padding: 2px 8px;
    border-radius: 10px;
    font-size: 10px;
    font-weight: 600;
    text-transform: uppercase;
}

.badge-success { background: rgba(34, 197, 94, 0.15); color: var(--success); }
.badge-warning { background: rgba(245, 158, 11, 0.15); color: var(--warning); }
.badge-danger { background: rgba(239, 68, 68, 0.15); color: var(--danger); }

/* Empty state */
.empty-state {
    text-align: center;
    padding: 40px 20px;
    color: var(--text-muted);
}

.empty-state .icon { font-size: 36px; margin-bottom: 12px; }
.empty-state p { font-size: 13px; }

/* Projects page */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 16px;
    padding: 16px 0;
}

.project-card {
    cursor: pointer;
    transition: border-color 0.15s;
}

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

.project-meta {
    font-size: 11px;
    color: var(--text-muted);
    margin-top: 8px;
}

/* Projects toolbar */
.projects-toolbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 16px;
    flex-wrap: wrap;
    gap: 12px;
}

.projects-controls {
    display: flex;
    gap: 8px;
    align-items: center;
}

.projects-search {
    padding: 6px 10px;
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: 5px;
    color: var(--text-primary);
    font-size: 12px;
    outline: none;
    width: 200px;
}

.projects-search:focus { border-color: var(--accent); }

.projects-sort {
    padding: 6px 10px;
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: 5px;
    color: var(--text-secondary);
    font-size: 12px;
    cursor: pointer;
}

/* Enhanced project cards */
.project-card-enhanced {
    transition: border-color 0.15s, box-shadow 0.15s;
}

.project-card-enhanced:hover {
    border-color: var(--accent);
    box-shadow: 0 2px 12px rgba(59, 130, 246, 0.08);
}

.project-card-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    padding: 12px 16px 8px;
}

.project-card-title {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.project-name {
    font-weight: 600;
    font-size: 14px;
    color: var(--text-primary);
}

.project-client {
    font-size: 12px;
    color: var(--accent);
}

.project-card-actions {
    display: flex;
    gap: 4px;
    opacity: 0;
    transition: opacity 0.15s;
}

.project-card-enhanced:hover .project-card-actions {
    opacity: 1;
}

.project-card-body {
    padding: 0 16px 12px;
    cursor: pointer;
}

.project-description {
    font-size: 12px;
    color: var(--text-muted);
    margin-bottom: 8px;
    line-height: 1.4;
}

.project-summary {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4px 12px;
    margin-bottom: 10px;
}

.project-summary-row {
    display: flex;
    justify-content: space-between;
    font-size: 11px;
    padding: 2px 0;
}

.summary-label {
    color: var(--text-muted);
}

.summary-value {
    color: var(--text-secondary);
    font-family: 'Consolas', 'Courier New', monospace;
    font-size: 11px;
}

.project-result-badge {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 12px;
    background: var(--accent-dim);
    border-radius: 6px;
}

.project-result-badge .result-loss {
    font-size: 16px;
    font-weight: 700;
    font-family: 'Consolas', 'Courier New', monospace;
    color: var(--accent);
}

.project-result-badge .result-label {
    font-size: 10px;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.project-result-badge.no-results {
    background: var(--bg-secondary);
}

.project-result-badge.no-results .result-label {
    color: var(--text-muted);
}

.project-card-footer {
    display: flex;
    justify-content: space-between;
    padding: 8px 16px;
    border-top: 1px solid var(--border);
    font-size: 10px;
    color: var(--text-muted);
}

/* Materials page */
.materials-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 12px;
    padding: 16px 0;
}

.material-card .card-body {
    font-size: 12px;
}

.material-prop {
    display: flex;
    justify-content: space-between;
    padding: 3px 0;
    border-bottom: 1px solid var(--border);
}

.material-prop:last-child { border-bottom: none; }
.material-prop .prop-label { color: var(--text-secondary); }
.material-prop .prop-value { font-family: 'Consolas', monospace; }

/* Toast notifications */
.toast {
    position: fixed;
    bottom: 20px;
    right: 20px;
    padding: 12px 20px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 13px;
    z-index: 1000;
    opacity: 0;
    transform: translateY(10px);
    transition: all 0.3s;
    max-width: 400px;
}

.toast.show { opacity: 1; transform: translateY(0); }
.toast.success { border-color: var(--success); }
.toast.error { border-color: var(--danger); }

/* Modal */
.modal-backdrop {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.6);
    z-index: 100;
    align-items: center;
    justify-content: center;
}

.modal-backdrop.show { display: flex; }

.modal {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 10px;
    width: 90%;
    max-width: 480px;
    max-height: 80vh;
    overflow-y: auto;
}

.modal-header {
    padding: 16px;
    border-bottom: 1px solid var(--border);
    font-weight: 600;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-body { padding: 16px; }

.modal-footer {
    padding: 12px 16px;
    border-top: 1px solid var(--border);
    display: flex;
    justify-content: flex-end;
    gap: 8px;
}

/* Scrollbar */
::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-track { background: var(--bg-primary); }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: var(--border-light); }

/* Preset selector in card header */
.preset-select {
    padding: 3px 8px;
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: 4px;
    color: var(--text-secondary);
    font-size: 11px;
    cursor: pointer;
    max-width: 180px;
}

.preset-select:focus { border-color: var(--accent); color: var(--text-primary); }

/* Dimension diagram */
.dimension-diagram {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 4px;
    margin-bottom: 12px;
}

.dimension-diagram svg {
    width: 100%;
    height: auto;
}

/* Input with unit suffix */
.input-with-unit {
    position: relative;
    display: flex;
    align-items: center;
}

.input-with-unit input {
    width: 100%;
    padding: 7px 10px;
    padding-right: 36px;
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: 5px;
    color: var(--text-primary);
    font-size: 13px;
    outline: none;
    transition: border-color 0.15s;
}

.input-with-unit input:focus { border-color: var(--accent); }

.input-with-unit .unit {
    position: absolute;
    right: 8px;
    font-size: 11px;
    color: var(--text-muted);
    pointer-events: none;
    font-weight: 500;
}

.input-with-unit .help-tip {
    pointer-events: auto;
    cursor: help;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: var(--border);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 10px;
    font-weight: 700;
    color: var(--text-secondary);
}

.input-with-unit .help-tip:hover { background: var(--accent); color: white; }

/* Config separator */
.config-separator {
    height: 1px;
    background: var(--border);
    margin: 14px 0;
}

/* Field hints */
.field-hint {
    font-size: 10px;
    color: var(--text-muted);
    margin-top: 3px;
    line-height: 1.4;
}

/* Area summary */
.area-summary {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 8px 10px;
    margin: 12px 0 8px;
    font-size: 11px;
}

.area-row {
    display: flex;
    justify-content: space-between;
    padding: 2px 0;
    color: var(--text-secondary);
}

.area-row span:last-child {
    font-family: 'Consolas', 'Courier New', monospace;
    font-size: 11px;
}

.area-row.area-total {
    border-top: 1px solid var(--border);
    margin-top: 4px;
    padding-top: 4px;
    font-weight: 600;
    color: var(--text-primary);
}

/* Zone toolbar */
.zone-toolbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 6px 12px;
    border-bottom: 1px solid var(--border);
    background: var(--bg-secondary);
}

.zone-desc {
    font-size: 11px;
    color: var(--text-secondary);
}

.zone-actions {
    display: flex;
    align-items: center;
    gap: 8px;
}

.zone-toggle {
    font-size: 11px;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 4px;
    cursor: pointer;
}

.zone-footer {
    padding: 8px 12px;
    display: flex;
    align-items: center;
    gap: 12px;
}

.zone-footer .add-layer-btn {
    flex: 1;
    margin-top: 0;
}

.total-thickness {
    font-size: 11px;
    color: var(--text-muted);
    font-family: 'Consolas', 'Courier New', monospace;
    white-space: nowrap;
}

/* Zone tab layer count badge */
.zone-layer-count {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 18px;
    height: 18px;
    border-radius: 9px;
    background: var(--border);
    font-size: 10px;
    font-weight: 600;
    color: var(--text-secondary);
    margin-left: 4px;
    padding: 0 4px;
}

.zone-tab.active .zone-layer-count {
    background: var(--accent-dim);
    color: var(--accent);
}

/* Layer item - improved */
.layer-item {
    display: grid;
    grid-template-columns: 28px 1fr 70px 28px;
    gap: 6px;
    align-items: center;
    padding: 6px 8px;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 6px;
    margin-bottom: 6px;
    transition: border-color 0.15s;
}

.layer-item:hover { border-color: var(--border-light); }

.layer-item select {
    padding: 5px 8px;
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: 4px;
    color: var(--text-primary);
    font-size: 12px;
}

.layer-item select optgroup {
    font-weight: 600;
    color: var(--accent);
    font-size: 12px;
}

.layer-item select option {
    font-weight: 400;
    color: var(--text-primary);
    padding: 2px 8px;
}

.layer-thickness-wrap {
    position: relative;
    display: flex;
    align-items: center;
}

.layer-thickness-wrap input {
    width: 100%;
    padding: 5px 8px;
    padding-right: 26px;
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: 4px;
    color: var(--text-primary);
    font-size: 12px;
    text-align: right;
}

.layer-thickness-wrap .unit-suffix {
    position: absolute;
    right: 6px;
    font-size: 10px;
    color: var(--text-muted);
    pointer-events: none;
}

/* Layer material info line */
.layer-info {
    grid-column: 2 / -1;
    font-size: 10px;
    color: var(--text-muted);
    padding-left: 2px;
    display: flex;
    gap: 10px;
}

.layer-info .over-temp {
    color: var(--danger);
    font-weight: 600;
}

/* ===================== */
/* Knowledge Base        */
/* ===================== */

.kb-layout {
    max-width: 900px;
    margin: 0 auto;
}

.kb-header {
    margin-bottom: 24px;
}

.kb-header h1 {
    font-size: 22px;
    font-weight: 700;
    margin-bottom: 6px;
}

.kb-header p {
    font-size: 13px;
    color: var(--text-secondary);
    margin-bottom: 16px;
}

.kb-search-wrap {
    margin-bottom: 12px;
}

.kb-search-wrap input {
    width: 100%;
    padding: 10px 16px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 14px;
    outline: none;
}

.kb-search-wrap input:focus { border-color: var(--accent); }

.kb-search-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 6px;
    font-size: 11px;
    color: var(--text-muted);
}

.kb-search-info button {
    background: none;
    border: none;
    color: var(--accent);
    cursor: pointer;
    font-size: 11px;
}

.kb-categories {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-bottom: 16px;
}

.kb-cat-btn {
    padding: 5px 12px;
    border-radius: 16px;
    border: 1px solid var(--border);
    background: var(--bg-card);
    color: var(--text-secondary);
    font-size: 12px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.15s;
}

.kb-cat-btn:hover { border-color: var(--accent); color: var(--text-primary); }
.kb-cat-btn.active { background: var(--accent); border-color: var(--accent); color: white; }

/* KB Items */
.kb-item {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 8px;
    margin-bottom: 8px;
    overflow: hidden;
    transition: border-color 0.15s;
}

.kb-item:hover { border-color: var(--border-light); }

.kb-question {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px 16px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    color: var(--text-primary);
    user-select: none;
}

.kb-q-icon {
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: var(--accent-dim);
    color: var(--accent);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 11px;
    font-weight: 700;
    flex-shrink: 0;
}

.kb-toggle {
    margin-left: auto;
    font-size: 18px;
    color: var(--text-muted);
    flex-shrink: 0;
    width: 24px;
    text-align: center;
}

.kb-answer {
    display: none;
    padding: 0 16px 16px 50px;
    font-size: 13px;
    color: var(--text-secondary);
    line-height: 1.6;
}

.kb-item.open .kb-answer { display: block; }
.kb-item.open { border-color: var(--accent); }

.kb-answer p { margin-bottom: 8px; }
.kb-answer ul, .kb-answer ol { padding-left: 18px; margin-bottom: 8px; }
.kb-answer li { margin-bottom: 3px; }
.kb-answer strong { color: var(--text-primary); }
.kb-answer a { color: var(--accent); text-decoration: none; }
.kb-answer a:hover { text-decoration: underline; }

.kb-answer .ref-table { margin: 8px 0 12px; }
.kb-answer .ref-info-box { margin: 8px 0 12px; }
.kb-answer .formula-box { margin: 8px 0 12px; }

/* Responsive */
@media (max-width: 1200px) {
    .calc-layout {
        grid-template-columns: 260px 1fr;
    }
    .results-panel {
        grid-column: 1 / -1;
    }
}

@media (max-width: 768px) {
    .calc-layout {
        grid-template-columns: 1fr;
    }

    /* Mobile nav — single row: [LOGO] [icons] [hamburger] */
    .top-bar {
        flex-wrap: wrap;
        height: auto;
        padding: 0 10px;
        gap: 4px;
        min-height: 52px;
    }
    .brand { flex-shrink: 0; order: 1; }
    /* Header icons sit after logo, push right with margin-left:auto */
    .header-actions { order: 2; margin-left: auto; gap: 4px; }
    /* Hamburger is last item on the row */
    .nav-toggle { display: flex; order: 3; margin-left: 4px; }
    /* Hide cluttered switchers on mobile — accessible from nav */
    .unit-switcher-wrap, .lang-switcher-wrap { display: none !important; }
    /* Nav drops below as full-width panel */
    .nav-links {
        display: none;
        order: 4;
        width: 100%;
        flex-direction: column;
        margin-left: 0;
        gap: 2px;
        padding: 8px 0;
        border-top: 1px solid var(--border);
    }
    .nav-links.open { display: flex; }
    .nav-links a {
        padding: 8px 12px;
        font-size: 13px;
    }
    .nav-dropdown { width: 100%; }
    .nav-dropdown-btn {
        width: 100%;
        padding: 8px 12px;
        font-size: 13px;
        justify-content: space-between;
    }
    .nav-dropdown-menu {
        position: static;
        box-shadow: none;
        border: none;
        border-left: 2px solid var(--border);
        padding: 4px 0 4px 12px;
        margin: 2px 0 2px 12px;
        background: transparent;
    }
    .nav-dropdown:hover .nav-dropdown-menu { display: none; }
    .nav-dropdown.open .nav-dropdown-menu { display: block; }
    .nav-dropdown-menu a { font-size: 12px; padding: 6px 10px; }

    /* Content padding */
    .content { padding: 10px; }

    /* Zone toolbar stacking */
    .zone-toolbar {
        flex-direction: column;
        align-items: flex-start;
        gap: 4px;
        padding: 8px 10px;
    }
    .zone-desc { font-size: 10px; }
    .zone-actions { width: 100%; justify-content: space-between; }

    /* Layer items: stack material above thickness */
    .layer-item {
        grid-template-columns: 28px 1fr 28px;
        grid-template-rows: auto auto;
    }
    .layer-item select {
        grid-column: 2 / 3;
        grid-row: 1;
    }
    .layer-thickness-wrap {
        grid-column: 2 / 3;
        grid-row: 2;
        max-width: 120px;
    }
    .layer-remove {
        grid-column: 3;
        grid-row: 1;
    }

    /* Results stat grid */
    .result-stats { padding: 8px 10px; gap: 6px; }
    .stat-value { font-size: 14px; }

    /* Result layers table scroll */
    .result-layers-table { display: block; overflow-x: auto; }
}

@media (max-width: 480px) {
    .brand-img { height: 30px; }
    .nav-links a { padding: 4px 8px; font-size: 11px; }
    .header-actions .btn { font-size: 10px; padding: 3px 6px; }
    .form-row { grid-template-columns: 1fr; }
    .result-stats { grid-template-columns: 1fr; }
    .projects-grid { grid-template-columns: 1fr; }
    .materials-grid { grid-template-columns: 1fr; }
}

/* ===================== */
/* Atmosphere Reference  */
/* ===================== */

.ref-layout {
    display: grid;
    grid-template-columns: 200px 1fr;
    gap: 16px;
    min-height: calc(100vh - 88px);
}

/* Sidebar */
.ref-sidebar {
    position: sticky;
    top: 72px;
    align-self: start;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 12px;
    max-height: calc(100vh - 100px);
    overflow-y: auto;
}

.ref-search-wrap {
    margin-bottom: 10px;
}

.ref-search-wrap input {
    width: 100%;
    padding: 6px 10px;
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: 5px;
    color: var(--text-primary);
    font-size: 12px;
    outline: none;
}

.ref-search-wrap input:focus, .ref-search:focus { border-color: var(--accent); }

/* Direct ref-search on input element (alternate pattern) */
input.ref-search {
    width: 100%;
    padding: 6px 10px;
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: 5px;
    color: var(--text-primary);
    font-size: 12px;
    outline: none;
    margin-bottom: 10px;
}

.ref-nav, .ref-nav-link {
    display: block;
    padding: 6px 10px;
    border-radius: 5px;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 12px;
    font-weight: 500;
    transition: all 0.15s;
    margin-bottom: 2px;
}

.ref-nav:hover, .ref-nav-link:hover { background: var(--bg-secondary); color: var(--text-primary); }
.ref-nav.active, .ref-nav-link.active { background: var(--accent-dim); color: var(--accent); }

/* Content */
.ref-content {
    overflow-y: auto;
    max-height: calc(100vh - 88px);
    padding-right: 8px;
}

.ref-section {
    margin-bottom: 32px;
}

.ref-section h2 {
    font-size: 18px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 8px;
    padding-bottom: 8px;
    border-bottom: 2px solid var(--accent);
}

.ref-section h3 {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-primary);
    margin: 16px 0 8px;
}

.ref-intro {
    font-size: 13px;
    color: var(--text-secondary);
    margin-bottom: 12px;
}

.ref-note {
    font-size: 11px;
    color: var(--text-muted);
    margin-top: 8px;
    font-style: italic;
}

/* Reference tables */
.ref-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 12px;
    margin-bottom: 16px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 6px;
    overflow: hidden;
}

.ref-table th {
    background: var(--bg-secondary);
    padding: 8px 12px;
    text-align: left;
    font-weight: 600;
    color: var(--text-secondary);
    font-size: 11px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    border-bottom: 1px solid var(--border);
    white-space: nowrap;
}

.ref-table td {
    padding: 6px 12px;
    border-bottom: 1px solid var(--border);
    color: var(--text-primary);
}

.ref-table tbody tr:last-child td { border-bottom: none; }
.ref-table tbody tr:hover { background: var(--bg-secondary); }
.ref-table tbody tr.search-highlight { background: rgba(59, 130, 246, 0.12); }
.ref-table tbody tr.search-highlight td { color: var(--text-primary); }

.ref-compact th, .ref-compact td {
    padding: 5px 8px;
    font-size: 11px;
    text-align: center;
}

.ref-compact td:first-child { text-align: left; font-weight: 500; }

.table-scroll {
    overflow-x: auto;
    margin-bottom: 16px;
}

/* Compatibility colours */
.compat-ok { color: var(--success); font-weight: 600; }
.compat-warn { color: var(--warning); font-weight: 600; }
.compat-bad { color: var(--danger); font-weight: 600; }

/* Safety systems YES/No */
td.yes { color: var(--danger); font-weight: 700; }
td.no { color: var(--text-muted); }
td.maybe { color: var(--warning); font-weight: 500; }

/* Two-column layout */
.ref-two-col {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

/* Atmosphere cards */
.atm-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 8px;
    margin-bottom: 12px;
    overflow: hidden;
}

.atm-header {
    padding: 10px 16px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    border-bottom: 1px solid var(--border);
    background: var(--bg-secondary);
}

.atm-header h3 {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-primary);
    margin: 0;
}

.atm-badge {
    padding: 3px 10px;
    border-radius: 12px;
    font-size: 10px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.3px;
}

.atm-badge.danger { background: rgba(239, 68, 68, 0.15); color: var(--danger); }
.atm-badge.warning { background: rgba(245, 158, 11, 0.15); color: var(--warning); }
.atm-badge.safe { background: rgba(34, 197, 94, 0.15); color: var(--success); }

/* Welding process badges */
.atm-badge.mig { background: rgba(59, 130, 246, 0.15); color: #3b82f6; }
.atm-badge.tig { background: rgba(34, 197, 94, 0.15); color: #22c55e; }
.atm-badge.stick { background: rgba(249, 115, 22, 0.15); color: #f97316; }
.atm-badge.gas-weld { background: rgba(234, 179, 8, 0.15); color: #eab308; }
.atm-badge.laser { background: rgba(168, 85, 247, 0.15); color: #a855f7; }
.atm-badge.fcaw { background: rgba(239, 68, 68, 0.15); color: #ef4444; }
.atm-badge.saw { background: rgba(20, 184, 166, 0.15); color: #14b8a6; }

/* Welding parameter tables — sticky header on wide scroll */
.weld-params-table thead th {
    position: sticky;
    top: 0;
    background: var(--bg-card);
    z-index: 2;
}

.atm-body {
    padding: 12px 16px;
}

.atm-body h4 {
    font-size: 11px;
    font-weight: 600;
    color: var(--accent);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin: 8px 0 4px;
}

.atm-body h4:first-child { margin-top: 0; }

.atm-body p {
    font-size: 12px;
    color: var(--text-secondary);
    line-height: 1.5;
    margin-bottom: 4px;
}

.atm-body ul {
    font-size: 12px;
    color: var(--text-secondary);
    padding-left: 16px;
    line-height: 1.6;
}

.atm-cols {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 16px;
}

/* Composition mini-table */
.atm-comp {
    width: 100%;
    border-collapse: collapse;
    font-size: 12px;
}

.atm-comp td {
    padding: 2px 6px;
    border-bottom: 1px solid var(--border);
}

.atm-comp td:first-child {
    font-weight: 600;
    color: var(--text-primary);
    font-family: 'Consolas', monospace;
}

.atm-comp td:last-child {
    text-align: right;
    font-family: 'Consolas', monospace;
    color: var(--text-secondary);
}

.atm-comp tr:last-child td { border-bottom: none; }

/* Cost bars */
.cost-bar {
    position: relative;
    min-width: 120px;
}

.cost-bar div {
    height: 6px;
    background: linear-gradient(90deg, var(--success), var(--warning), var(--danger));
    border-radius: 3px;
    margin-bottom: 2px;
    min-width: 4px;
}

/* Code blocks in reactions */
.ref-table code {
    font-family: 'Consolas', 'Courier New', monospace;
    font-size: 12px;
    color: var(--accent);
    background: var(--bg-input);
    padding: 1px 4px;
    border-radius: 3px;
}

/* Numbered step lists */
.ref-steps {
    font-size: 12px;
    color: var(--text-secondary);
    padding-left: 20px;
    line-height: 1.8;
    margin-bottom: 12px;
}

.ref-steps li {
    margin-bottom: 2px;
}

.ref-emergency li {
    font-weight: 500;
    color: var(--text-primary);
}

/* Formula boxes */
.formula-box {
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 10px 14px;
    margin: 8px 0 12px;
    text-align: center;
}

.formula-box code {
    font-family: 'Consolas', 'Courier New', monospace;
    font-size: 14px;
    color: var(--accent);
}

/* Gas train diagram */
.gas-train-diagram {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 14px;
    margin: 8px 0 12px;
    overflow-x: auto;
}

.gt-flow {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 12px;
    white-space: nowrap;
}

.gt-label {
    font-weight: 600;
    color: var(--text-primary);
    padding: 4px 8px;
}

.gt-arrow {
    color: var(--text-muted);
    font-size: 16px;
}

.gt-valve {
    padding: 5px 10px;
    border-radius: 4px;
    font-weight: 600;
    font-size: 11px;
}

.gt-nc {
    background: rgba(239, 68, 68, 0.15);
    color: var(--danger);
    border: 1px solid rgba(239, 68, 68, 0.3);
}

.gt-no {
    background: rgba(34, 197, 94, 0.15);
    color: var(--success);
    border: 1px solid rgba(34, 197, 94, 0.3);
}

/* Sidebar group labels */
.ref-nav-group {
    font-size: 9px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--text-muted);
    padding: 10px 10px 4px;
    margin-top: 6px;
    border-top: 1px solid var(--border);
}

.ref-nav-group:first-of-type { border-top: none; margin-top: 0; }

/* Sequence / code blocks */
.sequence-block {
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 12px 14px;
    margin: 8px 0 12px;
    font-family: 'Consolas', 'Courier New', monospace;
    font-size: 12px;
    color: var(--text-secondary);
    line-height: 1.6;
    white-space: pre-wrap;
    overflow-x: auto;
}

/* Ownership / consolidation tree */
.tree-block {
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 12px 14px;
    margin: 8px 0 12px;
    font-family: 'Consolas', 'Courier New', monospace;
    font-size: 12px;
    color: var(--text-secondary);
    line-height: 1.6;
    white-space: pre;
    overflow-x: auto;
}

/* Fault code highlight */
.fault-code {
    font-family: 'Consolas', monospace;
    font-weight: 600;
    color: var(--danger);
}

/* Info box (tips/warnings/danger) */
.ref-info-box {
    background: rgba(59, 130, 246, 0.08);
    border: 1px solid rgba(59, 130, 246, 0.2);
    border-radius: 6px;
    padding: 10px 14px;
    margin: 8px 0 12px;
    font-size: 12px;
    color: var(--text-secondary);
    line-height: 1.5;
}

.ref-info-box.warning {
    background: rgba(245, 158, 11, 0.08);
    border-color: rgba(245, 158, 11, 0.2);
}

.ref-info-box.danger {
    background: rgba(239, 68, 68, 0.08);
    border-color: rgba(239, 68, 68, 0.2);
}

.ref-info-box strong { color: var(--text-primary); }

/* Subsection h4 for manufacturer details */
.ref-section h4 {
    font-size: 13px;
    font-weight: 600;
    color: var(--accent);
    margin: 14px 0 6px;
}

/* Three column layout */
.ref-three-col {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 12px;
}

/* Sequence steps (procedure steps with numbered circles) */
.sequence-step, .seq-step {
    display: flex;
    gap: 12px;
    align-items: flex-start;
    padding: 10px 0;
    border-bottom: 1px solid var(--border);
}

.sequence-step:last-child, .seq-step:last-child { border-bottom: none; }

.sequence-number, .seq-num {
    flex-shrink: 0;
    width: 28px;
    height: 28px;
    border-radius: 50%;
    background: var(--accent);
    color: #fff;
    font-size: 12px;
    font-weight: 700;
    display: flex;
    align-items: center;
    justify-content: center;
}

.sequence-desc, .seq-desc {
    flex: 1;
    font-size: 12px;
    color: var(--text-secondary);
    line-height: 1.5;
}

.sequence-desc strong, .seq-desc strong { color: var(--text-primary); }

/* Step items (generic step list) */
.step-item {
    padding: 8px 0;
    border-bottom: 1px solid var(--border);
    font-size: 12px;
    color: var(--text-secondary);
    line-height: 1.5;
}

.step-item:last-child { border-bottom: none; }
.step-item strong { color: var(--text-primary); }

/* Reference info box lists */
.ref-info-box ul, .ref-info-box ol {
    margin: 6px 0 4px 16px;
    padding: 0;
}

.ref-info-box li {
    margin: 3px 0;
    font-size: 12px;
    line-height: 1.5;
}

/* Table scroll wrapper */
.table-scroll {
    overflow-x: auto;
    margin: 8px 0 12px;
    border-radius: 6px;
}

/* Ref-info-box h4 headings */
.ref-info-box h4 {
    font-size: 13px;
    font-weight: 600;
    color: var(--accent);
    margin: 0 0 6px;
}

.ref-info-box.danger h4 { color: var(--danger); }
.ref-info-box.warning h4 { color: var(--warning); }

/* Print styles for reference pages */
@media print {
    .ref-sidebar { display: none; }
    .ref-layout { grid-template-columns: 1fr; }
    .ref-content { max-height: none; overflow: visible; }
    .top-bar { display: none; }
    .ref-info-box.danger { border-color: red !important; border-width: 2px; }
}

/* Mobile sidebar toggle button (hidden by default, shown on mobile) */
.ref-sidebar-toggle {
    display: none;
    width: 100%;
    padding: 10px 14px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    margin-bottom: 8px;
    text-align: left;
    align-items: center;
    justify-content: space-between;
}
.ref-sidebar-toggle svg {
    transition: transform 0.2s;
}
.ref-sidebar-toggle.expanded svg {
    transform: rotate(180deg);
}

/* Responsive - Reference pages */
@media (max-width: 900px) {
    .ref-layout {
        grid-template-columns: 1fr;
    }
    .ref-sidebar {
        position: static;
        max-height: 0;
        overflow: hidden;
        padding: 0 12px;
        border: none;
        transition: max-height 0.3s ease, padding 0.3s ease, border 0.3s ease;
    }
    .ref-sidebar.mobile-open {
        max-height: 500px;
        overflow-y: auto;
        padding: 12px;
        border: 1px solid var(--border);
    }
    .ref-sidebar-toggle {
        display: flex;
    }
    .ref-content {
        max-height: none;
        overflow-y: visible;
    }
    .atm-cols {
        grid-template-columns: 1fr;
    }
    .ref-two-col {
        grid-template-columns: 1fr;
    }
    .ref-three-col {
        grid-template-columns: 1fr;
    }
    /* Gas train diagram: allow wrapping */
    .gt-flow {
        flex-wrap: wrap;
        white-space: normal;
    }
    .gt-valve, .gt-label { font-size: 10px; }
    /* Tables: horizontal scroll */
    .ref-table {
        display: block;
        overflow-x: auto;
    }
}

@media (max-width: 600px) {
    .ref-sidebar.mobile-open {
        max-height: 300px;
    }
    .ref-nav { font-size: 11px; padding: 4px 8px; }
    .ref-nav-group { font-size: 8px; padding: 6px 8px 2px; }
    .ref-section h2 { font-size: 15px; }
    .ref-section h3 { font-size: 13px; }
    .atm-body { padding: 8px 10px; }
    .atm-header { padding: 8px 10px; }
    .atm-header h3 { font-size: 13px; }
    .ref-table th, .ref-table td { padding: 4px 8px; font-size: 11px; }
    .sequence-block, .tree-block { font-size: 10px; padding: 8px 10px; }
    .formula-box code { font-size: 12px; }
}

/* ============================= */
/* Back to Top Button            */
/* ============================= */

.back-to-top {
    position: fixed;
    bottom: 24px;
    right: 24px;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--accent);
    color: white;
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 90;
    opacity: 0;
    transform: translateY(10px);
    transition: opacity 0.3s, transform 0.3s;
    pointer-events: none;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
}

.back-to-top.visible {
    opacity: 1;
    transform: translateY(0);
    pointer-events: auto;
}

.back-to-top:hover {
    background: var(--accent-hover);
    transform: translateY(-2px);
}

/* ============================= */
/* Theme Toggle                  */
/* ============================= */

.theme-toggle-btn {
    background: none;
    border: 1px solid var(--border);
    border-radius: 6px;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 6px 8px;
    display: flex;
    align-items: center;
    transition: all 0.2s;
}
.theme-toggle-btn:hover {
    border-color: var(--accent);
    color: var(--accent);
    background: var(--accent-dim);
}

.theme-icon-sun, .theme-icon-moon { display: block; }

/* ============================= */
/* Light Theme Override           */
/* ============================= */

.light-theme {
    --bg-primary: #f5f5f7;
    --bg-secondary: #ffffff;
    --bg-card: #ffffff;
    --bg-input: #f0f0f2;
    --border: #d4d4d8;
    --border-light: #c0c0c8;
    --text-primary: #1a1a2e;
    --text-secondary: #4a4a5a;
    --text-muted: #6b7280;
    --accent: #2563eb;
    --accent-hover: #1d4ed8;
    --accent-dim: #dbeafe;
}

.light-theme .top-bar {
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
}

.light-theme .card,
.light-theme .mat-card,
.light-theme .atm-card,
.light-theme .kb-item {
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
}

.light-theme .ref-table th {
    background: #f0f0f5;
    color: #4a4a5a;
}

.light-theme .ref-info-box {
    background: rgba(37, 99, 235, 0.06);
    border-color: rgba(37, 99, 235, 0.15);
}

.light-theme .ref-info-box.warning {
    background: rgba(245, 158, 11, 0.06);
    border-color: rgba(245, 158, 11, 0.15);
}

.light-theme .ref-info-box.danger {
    background: rgba(239, 68, 68, 0.06);
    border-color: rgba(239, 68, 68, 0.15);
}

.light-theme .nav-dropdown-menu {
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
}

.light-theme .gs-modal {
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.2);
}

.light-theme .back-to-top {
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

.light-theme ::-webkit-scrollbar-track { background: var(--bg-primary); }
.light-theme ::-webkit-scrollbar-thumb { background: #c0c0c8; }
.light-theme ::-webkit-scrollbar-thumb:hover { background: #a0a0a8; }

/* ============================= */
/* Global Search Modal           */
/* ============================= */

.global-search-btn {
    background: none;
    border: 1px solid var(--border);
    border-radius: 6px;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 6px 10px;
    display: flex;
    align-items: center;
    gap: 6px;
    transition: all 0.2s;
}
.global-search-btn:hover {
    border-color: var(--accent);
    color: var(--accent);
    background: var(--accent-dim);
}

.gs-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.6);
    backdrop-filter: blur(4px);
    z-index: 10000;
    justify-content: center;
    padding-top: 12vh;
}
.gs-overlay.active {
    display: flex;
}

.gs-modal {
    width: 580px;
    max-width: 95vw;
    max-height: 65vh;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 12px;
    box-shadow: 0 20px 60px rgba(0,0,0,0.5);
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.gs-header {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 14px 16px;
    border-bottom: 1px solid var(--border);
}

.gs-input {
    flex: 1;
    background: none;
    border: none;
    outline: none;
    color: var(--text-primary);
    font-size: 16px;
    font-family: inherit;
}
.gs-input::placeholder {
    color: var(--text-muted);
}

.gs-kbd {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 4px;
    padding: 2px 6px;
    font-size: 11px;
    color: var(--text-muted);
    font-family: inherit;
}

.gs-results {
    overflow-y: auto;
    flex: 1;
    padding: 8px;
}

.gs-empty {
    padding: 30px 20px;
    text-align: center;
    color: var(--text-muted);
}
.gs-empty p {
    margin-bottom: 16px;
    font-size: 14px;
}

.gs-shortcuts {
    display: flex;
    gap: 16px;
    justify-content: center;
}
.gs-shortcut-item {
    font-size: 12px;
    color: var(--text-muted);
    display: flex;
    align-items: center;
    gap: 6px;
}
.gs-shortcut-item kbd {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 3px;
    padding: 1px 5px;
    font-size: 11px;
}

.gs-group {
    margin-bottom: 8px;
}
.gs-group-label {
    font-size: 11px;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    padding: 6px 12px 4px;
}

.gs-result-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 8px 12px;
    border-radius: 6px;
    color: var(--text-primary);
    text-decoration: none;
    cursor: pointer;
    transition: background 0.15s;
}
.gs-result-item:hover,
.gs-result-item.selected {
    background: var(--accent-dim);
}
.gs-result-item.selected {
    outline: 1px solid var(--accent);
}

.gs-result-title {
    font-size: 14px;
}
.gs-result-title mark {
    background: var(--accent);
    color: white;
    border-radius: 2px;
    padding: 0 2px;
}

.gs-result-arrow {
    color: var(--text-muted);
    font-size: 14px;
    opacity: 0;
    transition: opacity 0.15s;
}
.gs-result-item:hover .gs-result-arrow,
.gs-result-item.selected .gs-result-arrow {
    opacity: 1;
}

/* ============================= */
/* Related Links Grid            */
/* ============================= */

.related-links-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 12px;
    margin-top: 16px;
}

.related-link-card {
    display: flex;
    align-items: center;
    gap: 14px;
    padding: 14px 16px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 8px;
    text-decoration: none;
    color: var(--text-primary);
    transition: all 0.2s;
}
.related-link-card:hover {
    border-color: var(--accent);
    background: var(--accent-dim);
    transform: translateY(-1px);
}

.related-link-icon {
    font-size: 24px;
    min-width: 36px;
    text-align: center;
}

.related-link-info h4 {
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 2px;
}
.related-link-info p {
    font-size: 12px;
    color: var(--text-secondary);
    line-height: 1.4;
}

@media (max-width: 768px) {
    .gs-modal { max-height: 80vh; }
    .related-links-grid { grid-template-columns: 1fr; }
}

/* ============================= */
/* Site Footer                   */
/* ============================= */

.site-footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border);
    padding: 32px 24px 24px;
    margin-top: 40px;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.footer-section h4 {
    font-size: 13px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 10px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.footer-section a {
    display: block;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 13px;
    padding: 3px 0;
    transition: color 0.15s;
}
.footer-section a:hover {
    color: var(--accent);
}

.footer-small {
    font-size: 12px;
    color: var(--text-muted);
    line-height: 1.6;
}

.footer-version {
    margin-top: 8px;
    font-size: 11px;
    opacity: 0.7;
}

@media (max-width: 768px) {
    .footer-content {
        grid-template-columns: repeat(2, 1fr);
        gap: 20px;
    }
}

@media (max-width: 480px) {
    .footer-content {
        grid-template-columns: 1fr;
    }
}

/* ============================= */
/* Print Styles                  */
/* ============================= */

@media print {
    .top-bar, .site-footer, .nav-toggle, .global-search-btn,
    .gs-overlay, .ref-sidebar, .kb-categories, .kb-search-wrap,
    .header-actions { display: none !important; }

    body {
        background: white;
        color: black;
        font-size: 11pt;
    }

    .content {
        padding: 0;
    }

    .ref-layout {
        display: block;
    }

    .ref-content {
        margin: 0;
        padding: 0;
    }

    .ref-section {
        break-inside: avoid;
        page-break-inside: avoid;
        border: 1px solid #ccc;
        margin-bottom: 12px;
    }

    .ref-section h2 {
        color: black;
        border-bottom: 2px solid #333;
        font-size: 14pt;
    }

    .ref-section h3 {
        color: #333;
        font-size: 12pt;
    }

    table, .ref-table {
        border-collapse: collapse;
    }

    table th, table td, .ref-table th, .ref-table td {
        border: 1px solid #999;
        padding: 4px 8px;
        color: black;
        background: white !important;
    }

    table th, .ref-table th {
        background: #eee !important;
        font-weight: bold;
    }

    .atm-card, .kb-item {
        border: 1px solid #ccc;
        background: white !important;
    }

    .atm-card-title, .kb-question {
        color: black;
    }

    .kb-answer {
        display: block !important;
        max-height: none !important;
    }

    .ref-info-box {
        border: 1px solid #666;
        background: #f5f5f5 !important;
        color: black;
    }

    a { color: black; text-decoration: none; }
    a[href]:after { content: " (" attr(href) ")"; font-size: 9pt; color: #666; }
    .related-link-card a[href]:after { content: none; }

    /* Calculator print */
    .calc-layout { display: block !important; }
    .config-panel { margin-bottom: 20px; }
    .zone-builder { margin-bottom: 20px; }
    .results-panel { max-height: none !important; overflow: visible !important; }
    .btn, .btn-primary, .btn-calculate { display: none !important; }
    .preset-select { display: none !important; }
    .modal-backdrop { display: none !important; }
    .back-to-top { display: none !important; }
    .zone-tabs .zone-tab { border: 1px solid #ccc; }

    /* Force all zone content visible for print */
    .zone-content { display: block !important; }
}

/* ============================= */
/* Mobile Touch Targets           */
/* ============================= */

/* Mobile touch targets - ensure minimum 44px */
@media (max-width: 768px) {
    .btn, .btn-sm { min-height: 44px; min-width: 44px; }
    .zone-tab { min-height: 44px; padding: 10px 16px; }
    .layer-remove { min-width: 44px; min-height: 44px; }
    .add-layer-btn { min-height: 44px; }
    .nav-links a { min-height: 44px; display: flex; align-items: center; }
    .nav-dropdown-btn { min-height: 44px; }
    .theme-toggle-btn, .global-search-btn { min-width: 44px; min-height: 44px; }
    .ref-nav, .ref-nav-link { min-height: 40px; display: flex; align-items: center; }
    .kb-question { min-height: 48px; }
}

/* ============================= */
/* Calculator Pages              */
/* ============================= */

.calc-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    margin: 16px 0;
}

.calc-inputs {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.calc-field {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.calc-field label {
    font-size: 13px;
    font-weight: 600;
    color: var(--text-primary);
}

.calc-field input,
.calc-field select {
    padding: 8px 12px;
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: 6px;
    color: var(--text-primary);
    font-size: 14px;
    font-family: inherit;
}

.calc-field input:focus,
.calc-field select:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 2px rgba(59, 130, 246, 0.15);
}

.calc-field small {
    font-size: 11px;
    color: var(--text-muted);
    line-height: 1.3;
}

.calc-btn {
    margin-top: 8px;
    padding: 10px 20px;
    font-size: 14px;
    font-weight: 600;
}

.calc-results {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 20px;
    min-height: 200px;
}

.calc-placeholder {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100%;
    min-height: 180px;
    color: var(--text-muted);
    font-size: 14px;
    font-style: italic;
}

.calc-result-title {
    font-size: 15px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 12px;
    padding-bottom: 8px;
    border-bottom: 1px solid var(--border);
}

.comparison-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

.comparison-col {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.ref-small {
    font-size: 11px;
    color: var(--text-muted);
    margin-top: 8px;
    line-height: 1.4;
}

@media (max-width: 768px) {
    .calc-grid {
        grid-template-columns: 1fr;
    }
    .comparison-row {
        grid-template-columns: 1fr;
    }
}


/* ── Fabrication Calculators ────────────────────────────────────────── */

.fab-svg-container {
    margin: 16px 0;
    overflow-x: auto;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 16px;
    text-align: center;
}

.fab-svg-container:empty { display: none; }

.fab-pattern-svg {
    display: inline-block;
    max-width: 100%;
    height: auto;
}

.fab-print-btn {
    margin-top: 12px;
    padding: 8px 20px;
    background: var(--accent);
    color: #fff;
    border: none;
    border-radius: 6px;
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.15s;
}
.fab-print-btn:hover { background: var(--accent-hover); }

/* SVG pattern classes */
.fab-pattern-svg .cut-line { stroke: var(--accent); stroke-width: 1.5; fill: none; }
.fab-pattern-svg .bend-line { stroke: var(--warning); stroke-width: 1; stroke-dasharray: 6,3; fill: none; }
.fab-pattern-svg .dim-line { stroke: var(--text-muted); stroke-width: 0.5; fill: none; }
.fab-pattern-svg .dim-text { font-size: 10px; fill: var(--text-secondary); font-family: -apple-system, sans-serif; }
.fab-pattern-svg .pattern-fill { fill: var(--bg-secondary); stroke: none; }
.fab-pattern-svg .label-text { font-size: 12px; fill: var(--text-primary); font-weight: 600; font-family: -apple-system, sans-serif; }
.fab-pattern-svg .info-text { font-size: 10px; fill: var(--text-secondary); font-family: -apple-system, sans-serif; }

@media print {
    .fab-svg-container { border: none; background: white; padding: 8px; }
    .fab-print-btn { display: none !important; }
    .fab-pattern-svg .cut-line { stroke: #000; }
    .fab-pattern-svg .bend-line { stroke: #666; }
    .fab-pattern-svg .dim-line { stroke: #999; }
    .fab-pattern-svg .dim-text { fill: #333; }
    .fab-pattern-svg .pattern-fill { fill: #f5f5f5; }
    .fab-pattern-svg .label-text { fill: #000; }
    .fab-pattern-svg .info-text { fill: #666; }
}

/* ── 3D Model + 2D Drawing Visualisation ───────────────────────────── */

.fab-viz-row {
    display: flex;
    gap: 16px;
    margin: 16px 0;
}

.fab-3d-container {
    flex: 1;
    min-width: 0;
    background: #15171c;
    border: 1px solid var(--border);
    border-radius: 8px;
    overflow: hidden;
}

.fab-3d-viewport {
    width: 100%;
    aspect-ratio: 4 / 3;
    cursor: grab;
}
.fab-3d-viewport:active { cursor: grabbing; }
.fab-3d-viewport canvas { display: block; width: 100% !important; height: 100% !important; }

.fab-drawing-container {
    flex: 1;
    min-width: 0;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 12px;
    overflow: hidden;
}

.fab-drawing-container svg {
    width: 100%;
    height: auto;
    display: block;
}

/* 2D Drawing SVG classes */
.fab-drawing-container .outline-line { stroke: var(--text-primary); stroke-width: 1.5; fill: none; }
.fab-drawing-container .hidden-line { stroke: var(--text-muted); stroke-width: 0.8; stroke-dasharray: 6,3; fill: none; }
.fab-drawing-container .centre-line { stroke: var(--accent); stroke-width: 0.5; stroke-dasharray: 16,3,4,3; fill: none; }
.fab-drawing-container .dim-line { stroke: var(--text-secondary); stroke-width: 0.4; fill: none; }
.fab-drawing-container .dim-text { font-size: 9px; fill: var(--text-secondary); font-family: 'Consolas', monospace; }
.fab-drawing-container .hatch-line { stroke: var(--text-muted); stroke-width: 0.3; opacity: 0.5; fill: none; }
.fab-drawing-container .view-label { font-size: 10px; fill: var(--text-muted); font-family: -apple-system, sans-serif; font-weight: 600; }
.fab-drawing-container .title-block { font-size: 8px; fill: var(--text-muted); font-family: 'Consolas', monospace; }

@media (max-width: 900px) {
    .fab-viz-row {
        flex-direction: column;
    }
}

@media print {
    .fab-3d-container { display: none !important; }
    .fab-viz-row { display: block; }
    .fab-drawing-container {
        width: 100%;
        border: 1px solid #ccc;
        background: white;
    }
    .fab-drawing-container .outline-line { stroke: #000; }
    .fab-drawing-container .hidden-line { stroke: #999; }
    .fab-drawing-container .centre-line { stroke: #666; }
    .fab-drawing-container .dim-line { stroke: #666; }
    .fab-drawing-container .dim-text { fill: #333; }
    .fab-drawing-container .hatch-line { stroke: #ccc; }
    .fab-drawing-container .view-label { fill: #333; }
}

/* ── Content Gating ─────────────────────────────────────────────────── */

.content-gated {
    position: relative;
    overflow: hidden;
}

.content-preview-fade {
    max-height: var(--preview-height, 200px);
    overflow: hidden;
    position: relative;
}

.content-preview-fade::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 120px;
    background: linear-gradient(transparent, var(--bg-primary));
    pointer-events: none;
}

.content-gate-overlay {
    position: relative;
    text-align: center;
    padding: 2.5rem 2rem;
    margin-top: -40px;
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: 16px;
    z-index: 1;
}

.gate-icon {
    margin-bottom: 1rem;
    color: var(--accent);
}

.content-gate-overlay h3 {
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
}

.content-gate-overlay p {
    color: var(--text-secondary);
    max-width: 480px;
    margin: 0 auto 1.5rem;
    font-size: 0.9rem;
    line-height: 1.6;
}

.gate-buttons {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.75rem;
}

.gate-buttons .btn-outline {
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text-secondary);
    padding: 0.5rem 1.5rem;
    border-radius: 8px;
    font-size: 0.85rem;
    text-decoration: none;
    transition: all 0.2s;
}

.gate-buttons .btn-outline:hover {
    border-color: var(--accent);
    color: var(--accent);
}


/* ── Contact CTA Block ──────────────────────────────────────────────── */

.contact-cta-block {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1.5rem;
    background: linear-gradient(135deg, var(--accent-dim), var(--bg-card));
    border: 1px solid var(--accent);
    border-radius: 12px;
    padding: 1.5rem 2rem;
    margin: 2rem 0;
}

.contact-cta-content h4 {
    font-size: 1.05rem;
    margin-bottom: 0.25rem;
}

.contact-cta-content p {
    color: var(--text-secondary);
    font-size: 0.88rem;
    margin: 0;
}

@media (max-width: 600px) {
    .contact-cta-block {
        flex-direction: column;
        text-align: center;
    }
}


/* ── Tier Badge ─────────────────────────────────────────────────────── */

.tier-badge {
    display: inline-block;
    padding: 2px 10px;
    border-radius: 20px;
    font-size: 0.7rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.tier-badge.registered { background: rgba(245,158,11,0.15); color: #f59e0b; }
.tier-badge.pro { background: rgba(16,185,129,0.15); color: #10b981; }
.tier-badge.enterprise { background: rgba(99,102,241,0.15); color: #6366f1; }
.tier-badge.admin { background: rgba(239,68,68,0.15); color: #ef4444; }