/* ==========================================================================
   1. CSS VARIABLES & THEME ("Industrial Hardware" Palette)
   ========================================================================== */
:root {
    /* Color Palette - Deep Matte Graphite Base */
    --bg-app: #0e0e0e;          /* Almost black, zero saturation */
    --bg-panel: #151515;        /* Distinct but subtle panel lift */
    --bg-surface: #1e1e1e;      /* Inputs, cards */
    --bg-surface-hover: #262626;
    
    --border-subtle: #242424;
    --border-strong: #333333;
    
    /* Typography */
    --text-primary: #e3e3e0;    /* Bone white, easier on eyes than pure #FFF */
    --text-secondary: #8c8c88;  /* Warm, desaturated gray */
    --text-tertiary: #5e5e5b;   /* Deep gray for structural text */
    
    /* Tactile/Physical Accents (No neons) */
    --accent-primary: #e3e3e0;          /* Main action uses high-contrast bone */
    --accent-primary-invert: #0e0e0e;   /* Text inside primary button */
    --accent-primary-hover: #cccccc;
    
    --accent-rust: #bc583b;     /* Replaces Pink: Matte burnt orange */
    --accent-sage: #6b7d62;     /* Replaces Green: Matte olive/sage */
    --accent-brass: #b89862;    /* Replaces Amber: Matte brass/gold */
    --accent-slate: #5e7382;    /* Replaces Cyan: Muted slate blue */
    
    /* Muted backgrounds for badges */
    --accent-sage-muted: rgba(107, 125, 98, 0.15);
    --accent-brass-muted: rgba(184, 152, 98, 0.15);

    /* Fonts */
    --font-ui: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'JetBrains Mono', ui-monospace, SFMono-Regular, monospace;
    
    /* Spacing & Layout */
    --radius-sm: 4px;           /* Tighter radii for a more engineered look */
    --radius-md: 8px;
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
}

/* ==========================================================================
   2. RESET & BASE
   ========================================================================== */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    background-color: var(--bg-app);
    color: var(--text-primary);
    font-family: var(--font-ui);
    font-size: 14px;
    line-height: 1.5;
    height: 100vh;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Custom Scrollbar - Engineered & Minimal */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}
::-webkit-scrollbar-track {
    background: transparent;
}
::-webkit-scrollbar-thumb {
    background: var(--border-strong);
    border-radius: 4px;
    border: 2px solid var(--bg-panel);
}
::-webkit-scrollbar-thumb:hover {
    background: var(--text-tertiary);
}

.hidden { display: none !important; }

#app:not(.hidden) {
    display: flex;
    flex-direction: column;
    flex: 1;
    min-height: 0;
    width: 100%;
}

.divider {
    width: 1px;
    height: 20px;
    background-color: var(--border-subtle);
    margin: 0 8px;
}

/* ==========================================================================
   3. LOADING SCREEN
   ========================================================================== */
#loading-screen {
    position: fixed;
    inset: 0;
    background-color: var(--bg-app);
    z-index: 50;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: opacity 0.5s ease;
}

.loading-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    max-width: 300px;
    width: 100%;
}

.loading-icon {
    font-size: 28px;
    color: var(--text-secondary);
    animation: spin 4s linear infinite;
    margin-bottom: 20px;
}

.loading-title {
    font-size: 14px;
    font-weight: 600;
    letter-spacing: 0.15em;
    color: var(--text-primary);
}

.loading-sub {
    font-size: 12px;
    color: var(--text-secondary);
    margin: 8px 0 24px 0;
}

.loading-bar-track {
    width: 100%;
    height: 2px;
    background-color: var(--border-subtle);
    overflow: hidden;
}

.loading-bar-fill {
    width: 30%;
    height: 100%;
    background-color: var(--text-primary);
    transition: width 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.loading-status {
    margin-top: 16px;
    font-size: 11px;
    font-family: var(--font-mono);
    color: var(--text-tertiary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

@keyframes spin { 100% { transform: rotate(360deg); } }

/* ==========================================================================
   4. LAYOUT: HEADER & TOOLBAR
   ========================================================================== */
.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 8px 24px;
    background-color: var(--bg-app);
    border-bottom: 1px solid var(--border-subtle);
    height: 48px;
    flex-shrink: 0;
}

.header-left, .header-center, .header-right {
    display: flex;
    align-items: center;
    gap: 16px;
}

.header-center {
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
}

.cpu-icon {
    font-size: 18px;
    color: var(--text-tertiary);
}

.header-title {
    font-size: 13px;
    font-weight: 600;
    letter-spacing: 0.1em;
    color: var(--text-primary);
}

.header-sub {
    font-size: 11px;
    color: var(--text-secondary);
    margin-top: 2px;
}

.stat-chip {
    display: flex;
    align-items: center;
    background-color: var(--bg-panel);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-sm);
    padding: 4px 12px;
}

.stat-label {
    font-size: 10px;
    font-weight: 600;
    color: var(--text-tertiary);
    margin-right: 12px;
    letter-spacing: 0.08em;
}

.stat-val {
    font-family: var(--font-mono);
    font-size: 12px;
    color: var(--text-primary);
}

.status-badge {
    font-size: 10px;
    font-weight: 600;
    padding: 4px 10px;
    border-radius: 999px;
    letter-spacing: 0.08em;
}
.status-badge.ready {
    background-color: var(--accent-sage-muted);
    color: var(--accent-sage);
}

.wasm-badge {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 10px;
    font-weight: 600;
    color: var(--text-secondary);
    letter-spacing: 0.08em;
}
.wasm-dot {
    width: 6px;
    height: 6px;
    background-color: var(--accent-brass);
    border-radius: 50%;
}

/* Toolbar */
.toolbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 7px 20px;
    background-color: var(--bg-panel);
    border-bottom: 1px solid var(--border-subtle);
    flex-shrink: 0;
}

.toolbar-left, .toolbar-right {
    display: flex;
    align-items: center;
    gap: 12px;
}

/* ==========================================================================
   5. UI COMPONENTS: BUTTONS & INPUTS
   ========================================================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 6px 16px;
    font-family: var(--font-ui);
    font-size: 11px;
    font-weight: 600;
    border-radius: var(--radius-sm);
    cursor: pointer;
    border: 1px solid transparent;
    transition: all var(--transition-fast);
    outline: none;
    letter-spacing: 0.05em;
}

.btn:disabled {
    opacity: 0.3;
    cursor: not-allowed;
    pointer-events: none;
}

/* Industrial Primary Button: Bone White */
.btn-primary {
    background-color: var(--accent-primary);
    color: var(--accent-primary-invert);
}
.btn-primary:hover {
    background-color: var(--accent-primary-hover);
}

.btn-secondary {
    background-color: var(--bg-surface);
    color: var(--text-primary);
    border-color: var(--border-subtle);
}
.btn-secondary:hover {
    background-color: var(--bg-surface-hover);
    border-color: var(--border-strong);
}

.btn-ghost {
    background-color: transparent;
    color: var(--text-secondary);
}
.btn-ghost:hover {
    background-color: var(--bg-surface);
    color: var(--text-primary);
}

/* Speed Slider */
.speed-label {
    font-size: 10px;
    font-weight: 600;
    color: var(--text-tertiary);
    letter-spacing: 0.08em;
}
input[type=range] {
    -webkit-appearance: none;
    width: 100px;
    background: transparent;
}
input[type=range]::-webkit-slider-thumb {
    -webkit-appearance: none;
    height: 12px;
    width: 6px; /* Boxy thumb for hardware feel */
    background: var(--text-primary);
    cursor: pointer;
    margin-top: -4px;
    border-radius: 1px;
}
input[type=range]::-webkit-slider-runnable-track {
    width: 100%;
    height: 4px;
    cursor: pointer;
    background: var(--border-strong);
    border-radius: 2px;
}
.speed-val {
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--text-secondary);
    min-width: 40px;
    text-align: right;
}

/* ==========================================================================
   6. MAIN LAYOUT & PANELS
   ========================================================================== */
.main-grid {
    display: grid;
    /* Editor (left) stays compact; PCB/Memory (mid) gets most space for diagrams/grid; CPU State (right) stays compact */
    grid-template-columns: minmax(260px, 1.15fr) minmax(420px, 1.8fr) minmax(300px, 1.15fr);
    gap: 1px;
    background-color: var(--border-subtle);
    flex: 1;
    min-height: 0;
}

.panel {
    background-color: var(--bg-app);
    display: flex;
    flex-direction: column;
    overflow: hidden;
    min-height: 0;
}

/* ── Right panel sub-sections ─────────────────────────────────────────── */
/* PCB always-on: Gets all remaining flex space */
.pcb-always-section {
    flex: 1;
    display: flex;
    flex-direction: column;
    min-height: 0;
    border-bottom: 1px solid var(--border-subtle);
}
.pcb-always-section .pcb-svg-wrap {
    flex: 1;
    min-height: 0;
}

/* Memory grid always-on: fixed height explicitly to prevent scrolling */
.memory-section {
    flex: 0 0 auto;
    display: flex;
    flex-direction: column;
    overflow: visible;
}

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

.panel-title {
    font-size: 10px;
    font-weight: 600;
    color: var(--text-secondary);
    letter-spacing: 0.1em;
}

.panel-chip {
    font-size: 10px;
    font-family: var(--font-mono);
    background-color: var(--bg-surface);
    padding: 2px 6px;
    border-radius: 2px;
    color: var(--text-secondary);
    border: 1px solid var(--border-subtle);
}

/* ==========================================================================
   7. EDITOR PANEL
   ========================================================================== */
.editor {
    flex: 1;
    width: 100%;
    background-color: transparent;
    border: none;
    padding: 20px 24px;
    color: var(--text-primary);
    font-family: var(--font-mono);
    font-size: 13px;
    line-height: 1.6;
    resize: none;
    outline: none;
}
.editor::selection {
    background-color: rgba(227, 227, 224, 0.15); /* Subtle bone highlight */
}

.editor-footer {
    padding: 8px 16px;
    border-top: 1px solid var(--border-subtle);
    background-color: var(--bg-panel);
    display: flex;
    justify-content: space-between;
    font-size: 10px;
    color: var(--text-tertiary);
    font-family: var(--font-mono);
}

/* ISA Quick Reference — collapsible details/summary */
.isa-ref {
    border-top: 1px solid var(--border-subtle);
    background-color: var(--bg-panel);
    flex-shrink: 0;       /* don't compress; editor above fills space */
}

/* summary row (the clickable header) */
.isa-ref > summary.isa-title {
    list-style: none;     /* remove default triangle */
    display: flex;
    align-items: center;
    gap: 7px;
    padding: 10px 16px;
    margin: 0;
    font-size: 9px;
    font-weight: 600;
    color: var(--text-tertiary);
    letter-spacing: 0.1em;
    cursor: pointer;
    user-select: none;
    transition: color 0.2s;
}
.isa-ref > summary.isa-title::-webkit-details-marker { display: none; }
.isa-ref > summary.isa-title::marker           { display: none; }
.isa-ref > summary.isa-title:hover { color: var(--text-secondary); }

/* rotate arrow when open */
.isa-ref[open] > summary.isa-title::before { content: '\25BC'; }
.isa-ref:not([open]) > summary.isa-title::before { content: '\25B6'; }

/* grid that expands below the summary */
.isa-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
    padding: 0 16px 14px;
}
.isa-group-title {
    font-size: 9px;
    color: var(--text-secondary);
    margin-bottom: 5px;
    letter-spacing: 0.05em;
}
.isa-group code {
    display: block;
    font-family: var(--font-mono);
    font-size: 10px;
    color: var(--text-secondary);
    margin-bottom: 3px;
}

/* ==========================================================================
   8. CPU STATE PANEL
   ========================================================================== */
.registers {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1px;
    background-color: var(--border-subtle); /* Creates inner borders */
    border-bottom: 1px solid var(--border-subtle);
}

.reg-card {
    background-color: var(--bg-app);
    padding: 10px 14px;
    display: grid;
    grid-template-areas: 
        "name dec"
        "hex hex"
        "track track"
        "bits bits";
    row-gap: 5px;
}

.pc-card {
    grid-column: span 2;
}

.reg-name {
    grid-area: name;
    font-size: 11px;
    font-weight: 600;
    color: var(--text-secondary);
    letter-spacing: 0.05em;
}

.reg-dec {
    grid-area: dec;
    text-align: right;
    font-size: 11px;
    font-family: var(--font-mono);
    color: var(--text-tertiary);
}

.reg-hex {
    grid-area: hex;
    font-size: 16px;
    font-family: var(--font-mono);
    color: var(--text-primary);
    line-height: 1;
}

.reg-track {
    grid-area: track;
    height: 2px;
    background-color: var(--bg-surface);
    overflow: hidden;
}

.reg-bar {
    height: 100%;
    width: 0%;
    background-color: var(--text-primary);
    transition: width 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}
.pc-bar { background-color: var(--accent-rust); }

.reg-bits {
    grid-area: bits;
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--text-tertiary);
    letter-spacing: 0.25em;
    text-align: center;
}

.sub-section {
    display: flex;
    flex-direction: column;
    min-height: 0;
}

/* Disassembly gets 2× the space vs exec-log, always shows at least ~4 instructions */
.disasm-section {
    flex: 2;
    min-height: 120px;
}
.disasm-section .disasm {
    flex: 1;
    min-height: 0;
}

/* Exec log: 1× share, always shows at least a few entries */
.exec-log-section {
    flex: 1;
    min-height: 80px;
}
.exec-log-section .exec-log {
    flex: 1;
    min-height: 0;
}

.sub-title {
    padding: 7px 16px;
    font-size: 9px;
    font-weight: 600;
    color: var(--text-tertiary);
    letter-spacing: 0.1em;
    background-color: var(--bg-panel);
    border-bottom: 1px solid var(--border-subtle);
    flex-shrink: 0;
}

.disasm, .exec-log {
    padding: 12px 16px;
    font-family: var(--font-mono);
    font-size: 12px;
    overflow-y: auto;
    color: var(--text-secondary);
    border-bottom: 1px solid var(--border-subtle);
}
.disasm-empty, .log-empty {
    color: var(--text-tertiary);
}

/* ==========================================================================
   9. MEMORY PANEL
   ========================================================================== */
/* Horizontal wrapping for data + program side-by-side */
.memory-heatmaps-wrap {
    display: flex;
    flex-direction: row;
    flex: 0 0 auto;
    overflow: visible;
}

.heatmap-col {
    display: flex;
    flex-direction: column;
    padding: 0 16px;
    flex-shrink: 0;
}

.heatmap-title {
    font-size: 9px;
    font-weight: 600;
    color: var(--text-tertiary);
    letter-spacing: 0.1em;
    padding: 12px 0 4px 0;
}

.heatmap-divider {
    height: auto;
    margin: 16px 0;
}

.tabs {
    display: flex;
    gap: 16px;
}
.tab {
    background: none;
    border: none;
    color: var(--text-tertiary);
    font-size: 10px;
    font-weight: 600;
    letter-spacing: 0.1em;
    cursor: pointer;
    padding: 4px 0;
    border-bottom: 2px solid transparent;
    transition: all var(--transition-fast);
}
.tab:hover { color: var(--text-secondary); }
.tab.active {
    color: var(--text-primary);
    border-bottom-color: var(--text-primary);
}

.grid-col-header {
    display: grid;
    grid-template-columns: 40px repeat(16, 14px);
    gap: 4px;
    padding: 8px 0;
    font-family: var(--font-mono);
    font-size: 10px;
    color: var(--text-tertiary);
    border-bottom: 1px solid var(--border-subtle);
}
.grid-col-header > div {
    text-align: center;
}

.grid-wrap {
    display: flex;
    flex: 0 0 auto;
    overflow: visible;
    padding: 16px 0;
}

.grid-row-labels {
    width: 40px;
    flex-shrink: 0;
    font-family: var(--font-mono);
    font-size: 10px;
    color: var(--text-tertiary);
    display: flex;
    flex-direction: column;
    gap: 4px;
}
.grid-row-lbl {
    height: 14px;
    line-height: 14px;
    text-align: right;
    padding-right: 8px;
}

.mem-grid {
    flex: 0 0 auto;
    display: grid;
    grid-template-columns: repeat(16, 14px);
    grid-auto-rows: 14px;
    gap: 4px; /* Heatmap gaps */
    align-content: start;
    justify-content: start;
}

.mem-grid > div {
    width: 14px;
    height: 14px;
    border-radius: 2px;
    font-size: 0; /* hides the text content */
    background-color: transparent;
    border: 1px solid transparent;
    transition: background-color var(--transition-fast), border-color var(--transition-fast);
}
.mem-grid > div:hover {
    cursor: crosshair;
    border-color: var(--text-secondary);
}

/* GitHub Contribution heatmap colors */
.mem-grid > div.heat-0 { background-color: #161b22; border-color: transparent; }
.mem-grid > div.heat-1 { background-color: #0e4429; border-color: transparent; }
.mem-grid > div.heat-2 { background-color: #006d32; border-color: transparent; }
.mem-grid > div.heat-3 { background-color: #26a641; border-color: transparent; }
.mem-grid > div.heat-4 { background-color: #39d353; border-color: transparent; }

/* Memory cursors/flags */
.mem-grid > div.pc-here {
    border: 2px solid var(--text-primary);
}

.mem-legend {
    display: flex;
    gap: 16px;
    padding: 12px 16px;
    border-top: 1px solid var(--border-subtle);
    background-color: var(--bg-panel);
    font-size: 10px;
    color: var(--text-secondary);
    letter-spacing: 0.05em;
}
.legend-item {
    display: flex;
    align-items: center;
    gap: 8px;
}
.legend-dot {
    width: 6px;
    height: 6px;
    border-radius: 1px;
}
.legend-dot.empty { background-color: #161b22; }
.legend-dot.mid { background-color: #006d32; }
.legend-dot.full { background-color: #39d353; }
.legend-dot.pc-border { border: 2px solid var(--text-primary); width: 8px; height: 8px; background-color: transparent; }

/* ==========================================================================
   10. RESPONSIVE DESIGN
   ========================================================================== */
@media (max-width: 1100px) {
    .main-grid {
        grid-template-columns: 1fr 1fr;
        grid-template-rows: auto 1fr;
    }
    .editor-panel {
        grid-column: span 2;
    }
}

@media (max-width: 800px) {
    body { height: auto; overflow: visible; }
    
    .header, .toolbar {
        flex-direction: column;
        align-items: flex-start;
        height: auto;
        gap: 16px;
    }
    
    .header-center {
        position: static;
        transform: none;
    }
    
    .main-grid {
        grid-template-columns: 1fr;
        display: flex;
        flex-direction: column;
        gap: 1px;
    }
    
    .panel {
        min-height: 400px;
    }
}

/* ==========================================================================
   11. PCB DIAGRAM
   ========================================================================== */

/* Modal overlay */
.pcb-modal {
    position: fixed;
    inset: 0;
    z-index: 40;
    background-color: var(--bg-app);
    display: flex;
    flex-direction: column;
    animation: pcb-in 0.2s ease;
}
.pcb-modal.hidden { display: none; }
@keyframes pcb-in {
    from { opacity: 0; transform: translateY(12px); }
    to   { opacity: 1; transform: translateY(0); }
}

.pcb-modal-inner {
    display: flex;
    flex-direction: column;
    height: 100%;
}

.pcb-modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 24px;
    border-bottom: 1px solid var(--border-subtle);
    background-color: var(--bg-panel);
    flex-shrink: 0;
}
.pcb-header-left  { display: flex; align-items: center; gap: 14px; }
.pcb-header-center { display: flex; align-items: center; gap: 8px; }

.pcb-title {
    font-size: 12px;
    font-weight: 700;
    letter-spacing: 0.15em;
    color: var(--text-primary);
}
.pcb-subtitle {
    font-size: 11px;
    color: var(--text-tertiary);
    letter-spacing: 0.05em;
}
.pcb-signal-dot {
    width: 7px; height: 7px;
    border-radius: 50%;
    background: #3a5a1a;
}
#pcb-signal-text {
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--text-tertiary);
    letter-spacing: 0.05em;
}

/* Toolbar embedded inside PCB modal */
.pcb-inner-toolbar {
    background-color: var(--bg-app);
    border-top: none;
    border-bottom: 1px solid var(--border-subtle);
}

/* Message bar inside PCB modal */
.message-bar {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px 20px;
    font-family: var(--font-mono);
    font-size: 12px;
    flex-shrink: 0;
    transition: all 0.3s;
}
.message-bar.hidden  { display: none; }
.message-bar.success { background: rgba(107,125,98,0.15); border-bottom: 1px solid rgba(107,125,98,0.25); color: var(--accent-sage); }
.message-bar.error   { background: rgba(188,88,59,0.12);  border-bottom: 1px solid rgba(188,88,59,0.25);  color: var(--accent-rust); }
.msg-close { background: none; border: none; cursor: pointer; color: inherit; font-size: 14px; margin-left: auto; opacity: 0.7; }
.msg-close:hover { opacity: 1; }

.pcb-modal-body {
    display: flex;
    flex: 1;
    min-height: 0;
    gap: 1px;
    background-color: var(--border-subtle);
}

/* PCB inline pane inside memory panel */
.pcb-panel-wrap {
    display: flex;
    flex: 1;
    min-height: 0;
    flex-direction: column;
    overflow: hidden;
}

.pcb-panel-controls {
    display: flex;
    align-items: center;
    gap: 6px;
    margin-left: 8px;
}

/* SVG canvas area */
.pcb-svg-wrap {
    flex: 1;
    min-height: 0;
    position: relative;
    overflow: hidden;
    background-color: #0a170a;
    cursor: grab;
}
.pcb-svg-wrap:active { cursor: grabbing; }
.pcb-svg {
    width: 100%;
    height: 100%;
    display: block;
    user-select: none;
}

.pcb-header-right {
    display: flex;
    align-items: center;
    gap: 8px;
}
.pcb-zoom-chip {
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--text-tertiary);
    background-color: var(--bg-surface);
    padding: 3px 8px;
    border-radius: 2px;
    border: 1px solid var(--border-subtle);
    min-width: 44px;
    text-align: center;
}

/* ── SVG component styles (referenced via class in SVG) ────────────────────── */
.comp-pad  { fill: #122012; }
.comp-body { fill: #0d120d; stroke: #2a5a1a; stroke-width: 1; }
.comp-notch { fill: none; stroke: #1a3a1a; stroke-width: 1; }
.comp-pin  { fill: #5a7a30; rx: 1; }
.comp-label {
    fill: #4a8a4a;
    font-family: 'JetBrains Mono', monospace;
    font-size: 9px;
    font-weight: 700;
    text-anchor: middle;
    letter-spacing: 2px;
}
.comp-sub {
    fill: #2a5a2a;
    font-family: 'JetBrains Mono', monospace;
    font-size: 7px;
    text-anchor: middle;
    letter-spacing: 1px;
}
.comp-val {
    fill: #70d070;
    font-family: 'JetBrains Mono', monospace;
    font-size: 8px;
    font-weight: 700;
    text-anchor: middle;
    letter-spacing: 1px;
}
.board-label {
    fill: #1a3a1a;
    font-family: 'JetBrains Mono', monospace;
    font-size: 7px;
    letter-spacing: 1px;
}

/* Active component highlight */
.pcb-comp-active .comp-body   { stroke: #5ab04a; stroke-width: 1.5; }
.pcb-comp-active .comp-label  { fill: #80d060; }
.pcb-comp-active .comp-val    { fill: #a0f080; }

/* ── Trace styles ─────────────────────────────────────────────────────────── */
.pcb-trace {
    fill: none;
    stroke: #2a3a14;
    stroke-width: 2.5;
    stroke-linecap: round;
    stroke-linejoin: round;
}

/* Animated active trace */
.trace-active {
    stroke: #c8a030;
    stroke-width: 3;
    filter: url(#glow);
    marker-end: url(#arr-active);
    stroke-dasharray: 0; /* solid when flowing */
    animation: trace-flow 0.5s ease forwards;
}
@keyframes trace-flow {
    0%   { stroke: #4a7a20; filter: none; }
    30%  { stroke: #f0c040; filter: url(#glow-strong); }
    100% { stroke: #c8a030; filter: url(#glow); }
}

/* ── PCB dot / via circles ───────────────────────────────────────────────── */
.pcb-via {
    fill: #3a6020;
    stroke: #5a9030;
    stroke-width: 1;
}

/* ── ISA reference panel ────────────────────────────────────────────────── */
.pcb-isa-panel {
    width: 340px;
    flex-shrink: 0;
    background-color: var(--bg-app);
    display: flex;
    flex-direction: column;
    overflow: hidden;
}
.pcb-isa-title {
    padding: 12px 16px;
    font-size: 9px;
    font-weight: 700;
    letter-spacing: 0.15em;
    color: var(--text-tertiary);
    border-bottom: 1px solid var(--border-subtle);
    background-color: var(--bg-panel);
    flex-shrink: 0;
}
.pcb-isa-table {
    width: 100%;
    border-collapse: collapse;
    font-family: var(--font-mono);
    font-size: 11px;
    flex: 1;
    overflow-y: auto;
    display: block;
}
.pcb-isa-table thead {
    display: table;
    width: 100%;
    table-layout: fixed;
    border-bottom: 1px solid var(--border-subtle);
}
.pcb-isa-table tbody {
    display: block;
    overflow-y: auto;
    height: calc(100% - 30px);
}
.pcb-isa-table th {
    padding: 8px 10px;
    text-align: left;
    font-size: 9px;
    font-weight: 600;
    color: var(--text-tertiary);
    letter-spacing: 0.1em;
}
.isa-row {
    display: table;
    width: 100%;
    table-layout: fixed;
    border-bottom: 1px solid var(--border-subtle);
    transition: background 0.15s;
}
.isa-row:hover { background-color: var(--bg-panel); }
.isa-row td { padding: 6px 10px; color: var(--text-tertiary); }
.isa-op   { color: var(--text-secondary); font-weight: 500; width: 42%; }
.isa-code { color: var(--accent-brass);   width: 16%; }
.isa-desc { font-size: 10px; color: var(--text-tertiary); }

/* Active row in ISA table (matches last executed opcode) */
.isa-row-active td  { background-color: rgba(80, 50, 10, 0.4); }
.isa-row-active .isa-op   { color: #d4a840; }
.isa-row-active .isa-code { color: #f0c060; }