/* ═══════════════════════════════════════════════════════════════════
   Memory Visualizer — style.css  (v3 — inline viz, no modal)
   Aesthetic: Dark-terminal glassmorphism, JetBrains Mono + Syne
   ═══════════════════════════════════════════════════════════════════ */

/* ── Design Tokens ─────────────────────────────────────────────── */
:root {
    --bg-solid:        #0a0a0f;
    --bg-panel:        rgba(14, 14, 22, 0.72);
    --bg-panel-hover:  rgba(18, 18, 28, 0.85);
    --bg-card:         rgba(20, 20, 32, 0.8);
    --bg-input:        rgba(10, 10, 18, 0.9);

    --border:          rgba(255, 255, 255, 0.08);
    --border-accent:   rgba(99, 235, 200, 0.3);
    --border-strong:   rgba(255, 255, 255, 0.15);

    --text-primary:    #e8e8f0;
    --text-secondary:  #8888aa;
    --text-muted:      #55556a;
    --text-code:       #c0c8e8;

    --accent:          #6c8ef7;
    --accent-dim:      rgba(108, 142, 247, 0.15);
    --accent-glow:     rgba(108, 142, 247, 0.08);
    --accent-rgb:      108, 142, 247;

    --color-ref:       #7eb8ff;
    --color-val:       #f0c070;
    --color-type:      #e06c8a;
    --color-heap-id:   #a0aec0;
    --arrow-color:     rgba(108, 142, 247, 0.4);

    --status-ok:       #4ade80;
    --status-err:      #f87171;
    --status-warn:     #fbbf24;
    --status-idle:     #8888aa;

    --glass-blur:      24px;
    --glass-border:    rgba(255, 255, 255, 0.07);
    --glass-shadow:    0 8px 32px rgba(0, 0, 0, 0.5), 0 1px 0 rgba(255, 255, 255, 0.04) inset;

    --r-sm:  6px;
    --r-md:  10px;
    --r-lg:  16px;
    --r-xl:  20px;

    --font-ui:   'Syne', system-ui, sans-serif;
    --font-mono: 'JetBrains Mono', 'SF Mono', 'Fira Code', monospace;

    --ease:        cubic-bezier(0.25, 0.46, 0.45, 0.94);
    --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
}

/* ── Light theme ───────────────────────────────────────────────── */
[data-theme="light"] {
    --bg-solid:       #eeeff8;
    --bg-panel:       rgba(255, 255, 255, 0.72);
    --bg-panel-hover: rgba(255, 255, 255, 0.9);
    --bg-card:        rgba(248, 248, 255, 0.85);
    --bg-input:       rgba(240, 240, 250, 0.9);

    --border:         rgba(0, 0, 0, 0.08);
    --border-accent:  rgba(65, 102, 212, 0.25);
    --border-strong:  rgba(0, 0, 0, 0.14);

    --text-primary:   #0f0f1a;
    --text-secondary: #555570;
    --text-muted:     #99999c;
    --text-code:      #2a3060;

    --accent:         #4166d4;
    --accent-dim:     rgba(65, 102, 212, 0.1);
    --accent-glow:    rgba(65, 102, 212, 0.05);
    --accent-rgb:     65, 102, 212;

    --color-ref:      #0060c0;
    --color-val:      #a05000;
    --color-type:     #c0204a;
    --color-heap-id:  #606080;
    --arrow-color:    rgba(65, 102, 212, 0.35);

    --status-ok:      #16a34a;
    --status-err:     #dc2626;
    --status-warn:    #d97706;

    --glass-border:   rgba(0, 0, 0, 0.06);
    --glass-shadow:   0 8px 32px rgba(0, 0, 0, 0.08), 0 1px 0 rgba(255, 255, 255, 0.9) inset;
}

/* ── Reset & Base ──────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    margin: 0;
    font-family: var(--font-ui);
    font-size: 14px;
    line-height: 1.5;
    color: var(--text-primary);
    background: var(--bg-solid);
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}
body.no-scroll { overflow: hidden; }

/* ── Canvas Background ─────────────────────────────────────────── */
#bg-canvas {
    position: fixed;
    inset: 0;
    z-index: 0;
    pointer-events: none;
    background: var(--bg-solid);
}
.noise-overlay {
    position: fixed;
    inset: 0;
    z-index: 1;
    pointer-events: none;
    opacity: 0.025;
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)'/%3E%3C/svg%3E");
    background-size: 200px 200px;
}

/* ── App Shell ─────────────────────────────────────────────────── */
.app-shell {
    position: relative;
    z-index: 2;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* ── Glass Panel ───────────────────────────────────────────────── */
.glass-panel {
    background: var(--bg-panel);
    border: 1px solid var(--glass-border);
    backdrop-filter: blur(var(--glass-blur));
    -webkit-backdrop-filter: blur(var(--glass-blur));
    box-shadow: var(--glass-shadow);
}

/* ══════════════════════════════════════════════════════════════════
   HEADER
   ══════════════════════════════════════════════════════════════════ */
.app-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 2rem;
    height: 60px;
    background: var(--bg-panel);
    border-bottom: 1px solid var(--border);
    backdrop-filter: blur(var(--glass-blur));
    -webkit-backdrop-filter: blur(var(--glass-blur));
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-left { display: flex; align-items: center; gap: 14px; }

.logo-mark { width: 32px; height: 32px; flex-shrink: 0; }
.logo-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 3px;
    width: 100%;
    height: 100%;
}
.logo-grid span {
    border-radius: 2px;
    background: var(--border-strong);
    transition: background 0.3s;
}
.logo-grid span.logo-center {
    background: var(--accent);
    box-shadow: 0 0 8px rgba(var(--accent-rgb), 0.5);
}

.logo-text   { display: flex; flex-direction: column; }
.logo-title  { font-size: 1.05rem; font-weight: 700; letter-spacing: -0.02em; color: var(--text-primary); line-height: 1; }
.logo-sub    { font-size: 0.67rem; color: var(--text-muted); font-family: var(--font-mono); letter-spacing: 0.08em; text-transform: uppercase; margin-top: 1px; }
.accent-dot  { color: var(--accent); }

.header-right { display: flex; align-items: center; gap: 12px; }

.status-badge {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 4px 10px;
    border-radius: 20px;
    border: 1px solid var(--border);
    background: var(--bg-card);
    font-size: 0.72rem;
    font-family: var(--font-mono);
    color: var(--text-secondary);
    transition: all 0.3s;
}
.status-dot { width: 6px; height: 6px; border-radius: 50%; background: var(--status-idle); transition: background 0.3s; }
.status-badge.ok  .status-dot { background: var(--status-ok); box-shadow: 0 0 6px var(--status-ok); animation: pulse-dot 2s infinite; }
.status-badge.ok  .status-text { color: var(--status-ok); }
.status-badge.err .status-dot { background: var(--status-err); }
.status-badge.err .status-text { color: var(--status-err); }

.icon-btn {
    display: flex; align-items: center; justify-content: center;
    width: 36px; height: 36px;
    border-radius: var(--r-md);
    border: 1px solid var(--border);
    background: var(--bg-card);
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.2s var(--ease);
    padding: 0;
}
.icon-btn svg { width: 16px; height: 16px; }
.icon-btn:hover { background: var(--bg-panel-hover); color: var(--text-primary); border-color: var(--border-strong); }

.icon-moon { display: none; }
[data-theme="light"] .icon-sun  { display: none; }
[data-theme="light"] .icon-moon { display: block; }

/* ══════════════════════════════════════════════════════════════════
   LANGUAGE NAV
   ══════════════════════════════════════════════════════════════════ */
.lang-nav {
    background: var(--bg-panel);
    border-bottom: 1px solid var(--border);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
}
.lang-nav-inner {
    display: flex;
    max-width: 1600px;
    margin: 0 auto;
    padding: 0 1.5rem;
    overflow-x: auto;
    scrollbar-width: none;
    gap: 2px;
}
.lang-nav-inner::-webkit-scrollbar { display: none; }

.lang-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 18px;
    background: transparent;
    border: none;
    border-bottom: 2px solid transparent;
    border-radius: 0;
    color: var(--text-secondary);
    font-family: var(--font-ui);
    font-size: 0.88rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s var(--ease);
    white-space: nowrap;
    margin-bottom: -1px;
}
.lang-btn:hover { color: var(--text-primary); background: var(--accent-glow); }
.lang-btn.active {
    color: var(--text-primary);
    border-bottom-color: var(--accent);
    background: linear-gradient(to top, var(--accent-dim) 0%, transparent 100%);
}
.lang-icon { width: 20px; height: 20px; border-radius: 4px; overflow: hidden; flex-shrink: 0; }
.lang-label { font-weight: 600; }
.lang-pill {
    font-family: var(--font-mono);
    font-size: 0.65rem;
    padding: 2px 6px;
    border-radius: 4px;
    background: var(--accent-glow);
    color: var(--accent);
    border: 1px solid var(--border-accent);
    opacity: 0;
    transform: translateX(-4px);
    transition: all 0.2s;
}
.lang-btn.active .lang-pill,
.lang-btn:hover  .lang-pill { opacity: 1; transform: translateX(0); }

/* ══════════════════════════════════════════════════════════════════
   WORKSPACE — two equal columns
   ══════════════════════════════════════════════════════════════════ */
.workspace {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    padding: 1rem 1.5rem;
    max-width: 1600px;
    width: 100%;
    margin: 0 auto;
    flex: 1;
    /* natural height — columns stretch to match each other */
    align-items: start;
}

/* ══════════════════════════════════════════════════════════════════
   LEFT COLUMN — editor + console / html-editor
   ══════════════════════════════════════════════════════════════════ */
.editor-column {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    min-width: 0;
}

/* ── Panel header (shared) ────────────────────────────────────── */
.panel-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 9px 14px;
    border-bottom: 1px solid var(--border);
    background: rgba(0, 0, 0, 0.12);
    flex-shrink: 0;
}
[data-theme="light"] .panel-header { background: rgba(0, 0, 0, 0.03); }

.panel-title {
    display: flex;
    align-items: center;
    gap: 7px;
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-muted);
}
.panel-title svg { width: 12px; height: 12px; }

.lang-badge {
    font-family: var(--font-mono);
    font-size: 0.68rem;
    padding: 2px 8px;
    border-radius: 4px;
    background: var(--accent-glow);
    color: var(--accent);
    border: 1px solid var(--border-accent);
}

/* ── Editor panel ─────────────────────────────────────────────── */
.editor-panel {
    display: flex;
    flex-direction: column;
    border-radius: var(--r-lg);
    overflow: hidden;
    height: 62vh;
    min-height: 300px;
}
#editor-container { flex: 1; min-height: 0; }

/* ── Monaco current-line decoration ──────────────────────────── */
.current-exec-line {
    background: rgba(var(--accent-rgb), 0.10) !important;
}
.current-exec-glyph::before {
    content: 'â–¶';
    color: var(--accent);
    font-size: 10px;
    margin-left: 2px;
}

/* ── Console panel ────────────────────────────────────────────── */
.console-panel {
    border-radius: var(--r-lg);
    overflow: hidden;
    height: 180px;
    min-height: 80px;
    display: flex;
    flex-direction: column;
    flex-shrink: 0;
}
#console-output {
    flex: 1;
    margin: 0;
    padding: 12px 14px;
    font-family: var(--font-mono);
    font-size: 0.8rem;
    line-height: 1.6;
    color: var(--text-code);
    white-space: pre-wrap;
    word-break: break-all;
    overflow-y: auto;
    background: transparent;
    scrollbar-width: thin;
    scrollbar-color: var(--border) transparent;
}

/* ── HTML template editor panel ───────────────────────────────── */
.html-panel {
    border-radius: var(--r-lg);
    overflow: hidden;
    height: 200px;
    min-height: 80px;
    display: flex;
    flex-direction: column;
    flex-shrink: 0;
}
.html-editor-textarea {
    flex: 1;
    min-height: 0;
    resize: none;
    border: none;
    outline: none;
    background: var(--bg-input);
    color: var(--text-code);
    font-family: var(--font-mono);
    font-size: 0.78rem;
    line-height: 1.6;
    padding: 12px 14px;
    tab-size: 2;
    scrollbar-width: thin;
    scrollbar-color: var(--border) transparent;
}
.html-editor-textarea::-webkit-scrollbar { width: 5px; }
.html-editor-textarea::-webkit-scrollbar-thumb { background: var(--border-strong); border-radius: 3px; }
.html-hint {
    font-size: 0.65rem;
    font-family: var(--font-mono);
    color: var(--text-muted);
}

/* ══════════════════════════════════════════════════════════════════
   RIGHT COLUMN — viz panel
   ══════════════════════════════════════════════════════════════════ */
.viz-column {
    display: flex;
    flex-direction: column;
    min-width: 0;
}

.viz-panel {
    display: flex;
    flex-direction: column;
    border-radius: var(--r-lg);
    overflow: hidden;
    /* match editor-column height: editor (62vh) + gap + console (180px) */
    height: calc(62vh + 0.75rem + 180px);
    min-height: 400px;
}

/* ── Tab bar (JS only) ────────────────────────────────────────── */
.viz-tab-bar {
    display: flex;
    align-items: stretch;
    border-bottom: 1px solid var(--border);
    background: rgba(0, 0, 0, 0.14);
    position: relative;
    padding: 0 6px;
    gap: 0;
    flex-shrink: 0;
    overflow: hidden;
}
[data-theme="light"] .viz-tab-bar { background: rgba(0, 0, 0, 0.03); }

.viz-tab {
    display: flex;
    align-items: center;
    gap: 7px;
    padding: 10px 16px;
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-family: var(--font-ui);
    font-size: 0.8rem;
    font-weight: 600;
    cursor: pointer;
    transition: color 0.2s var(--ease);
    white-space: nowrap;
    position: relative;
    z-index: 1;
}
.viz-tab svg { width: 13px; height: 13px; flex-shrink: 0; }
.viz-tab:hover  { color: var(--text-primary); }
.viz-tab.active { color: var(--accent); }

/* Sliding ink underline */
.viz-tab-ink {
    position: absolute;
    bottom: 0;
    left: 0;
    height: 2px;
    width: 0;
    background: var(--accent);
    border-radius: 2px 2px 0 0;
    box-shadow: 0 0 8px rgba(var(--accent-rgb), 0.5);
    transition: left 0.25s var(--ease), width 0.25s var(--ease);
    z-index: 2;
}

/* ── Toolbar ──────────────────────────────────────────────────── */
.viz-toolbar {
    display: flex;
    align-items: center;
    gap: 5px;
    padding: 7px 10px;
    border-bottom: 1px solid var(--border);
    background: rgba(0, 0, 0, 0.10);
    flex-shrink: 0;
}
[data-theme="light"] .viz-toolbar { background: rgba(0, 0, 0, 0.03); }

/* generic toolbar icon button */
.toolbar-icon-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 30px;
    height: 30px;
    border-radius: var(--r-sm);
    border: 1px solid var(--border);
    background: var(--bg-card);
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.18s var(--ease);
    padding: 0;
    flex-shrink: 0;
    position: relative;
}
.toolbar-icon-btn svg { width: 13px; height: 13px; }
.toolbar-icon-btn:hover:not(:disabled) {
    background: var(--bg-panel-hover);
    color: var(--text-primary);
    border-color: var(--border-accent);
}
.toolbar-icon-btn:disabled { opacity: 0.3; cursor: not-allowed; }
.toolbar-icon-btn:active:not(:disabled) { transform: scale(0.93); }

/* compile bolt — slightly bigger, accent-colored */
.compile-btn-icon {
    width: 32px;
    height: 32px;
    background: var(--accent-dim);
    border-color: var(--border-accent);
    color: var(--accent);
}
.compile-btn-icon:hover:not(:disabled) {
    background: rgba(var(--accent-rgb), 0.25);
    color: var(--accent);
    border-color: var(--accent);
}
.compile-btn-icon.loading .compile-icon { display: none; }
.compile-icon { display: block; width: 13px; height: 13px; }

/* dot loader inside compile btn */
.dot-loader { display: none; gap: 3px; align-items: center; }
.compile-btn-icon.loading .dot-loader { display: flex; }
.dot-loader span {
    width: 4px; height: 4px;
    border-radius: 50%;
    background: var(--accent);
    animation: bounce 0.8s ease-in-out infinite;
}
.dot-loader span:nth-child(2) { animation-delay: 0.15s; }
.dot-loader span:nth-child(3) { animation-delay: 0.3s; }

/* play button — active state */
.toolbar-icon-btn.playing {
    background: var(--accent-dim);
    border-color: var(--border-accent);
    color: var(--accent);
}

/* vertical separator */
.toolbar-sep-v {
    width: 1px;
    height: 18px;
    background: var(--border-strong);
    margin: 0 3px;
    flex-shrink: 0;
}

/* step counter + mini progress */
.toolbar-step-wrap {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 3px;
    min-width: 56px;
}
.toolbar-step-num {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: 0.02em;
}
.toolbar-progress {
    width: 48px;
    height: 2px;
    border-radius: 1px;
    background: var(--border-strong);
    overflow: hidden;
}
.toolbar-progress-fill {
    height: 100%;
    background: var(--accent);
    width: 0%;
    transition: width 0.2s var(--ease);
    border-radius: 1px;
    box-shadow: 0 0 6px rgba(var(--accent-rgb), 0.6);
}

/* push right-side chips to the end */
.toolbar-spacer { flex: 1; }

/* line chip — "L42" */
.toolbar-line-chip {
    display: flex;
    align-items: center;
    gap: 4px;
    font-family: var(--font-mono);
    font-size: 0.68rem;
    font-weight: 600;
    color: var(--accent);
    padding: 3px 7px;
    background: var(--accent-glow);
    border: 1px solid var(--border-accent);
    border-radius: 4px;
    white-space: nowrap;
}
.toolbar-line-chip svg { width: 10px; height: 10px; }

/* steps count badge */
.toolbar-meta-badge {
    font-family: var(--font-mono);
    font-size: 0.67rem;
    color: var(--text-muted);
    padding: 3px 7px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 4px;
    white-space: nowrap;
}

/* language tag */
.toolbar-lang-badge {
    font-family: var(--font-mono);
    font-size: 0.67rem;
    color: var(--accent);
    padding: 3px 7px;
    background: var(--accent-glow);
    border: 1px solid var(--border-accent);
    border-radius: 4px;
    white-space: nowrap;
}

/* cold-start notice */
.cold-start-notice {
    display: none;
    align-items: flex-start;
    gap: 6px;
    padding: 7px 12px;
    background: rgba(251, 191, 36, 0.07);
    border-bottom: 1px solid rgba(251, 191, 36, 0.2);
    color: #fbbf24;
    font-size: 0.72rem;
    line-height: 1.4;
    flex-shrink: 0;
}
.cold-start-notice svg { width: 12px; height: 12px; flex-shrink: 0; margin-top: 1px; }
.cold-start-notice.visible { display: flex; }

/* ══════════════════════════════════════════════════════════════════
   VIZ BODY — holds empty-state, memory-grid, browser-run-panel
   ══════════════════════════════════════════════════════════════════ */
.viz-body {
    flex: 1;
    min-height: 0;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    position: relative;
}

/* ── Empty state ──────────────────────────────────────────────── */
.viz-empty-state {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 10px;
    padding: 2rem;
    text-align: center;
    color: var(--text-muted);
}
.empty-msg {
    margin: 0;
    font-size: 0.88rem;
    font-weight: 600;
    color: var(--text-secondary);
}
.empty-sub {
    margin: 0;
    font-size: 0.75rem;
    font-family: var(--font-mono);
    color: var(--text-muted);
}

/* ══════════════════════════════════════════════════════════════════
   MEMORY GRID  (now inline, not in a modal)
   ══════════════════════════════════════════════════════════════════ */
.memory-grid {
    flex: 1;
    display: grid;
    grid-template-columns: 1fr 1fr;
    position: relative;
    overflow: hidden;
    min-height: 0;
    height: 100%;
}

#arrow-svg {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 20;
    overflow: visible;
}

/* Memory Panes */
.memory-pane {
    display: flex;
    flex-direction: column;
    overflow: hidden;
    min-height: 0;
    height: 100%;
    border-right: 1px solid var(--border);
}
.memory-pane:last-child { border-right: none; }

.pane-header {
    display: flex;
    align-items: center;
    gap: 7px;
    padding: 9px 14px;
    background: rgba(0, 0, 0, 0.12);
    border-bottom: 1px solid var(--border);
    font-size: 0.7rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-secondary);
    flex-shrink: 0;
}
[data-theme="light"] .pane-header { background: rgba(0, 0, 0, 0.03); }
.pane-header svg { width: 12px; height: 12px; }
.pane-sub { text-transform: none; font-weight: 400; letter-spacing: 0; color: var(--text-muted); margin-left: 2px; }

.pane-body {
    flex: 1;
    min-height: 0;
    overflow-y: auto;
    overflow-x: hidden;
    padding: 12px;
    scrollbar-width: thin;
    scrollbar-color: var(--border-strong) transparent;
}
.pane-body::-webkit-scrollbar { width: 6px; }
.pane-body::-webkit-scrollbar-track { background: transparent; }
.pane-body::-webkit-scrollbar-thumb { background: var(--border-strong); border-radius: 3px; }
.pane-body::-webkit-scrollbar-thumb:hover { background: var(--accent); }

/* ══════════════════════════════════════════════════════════════════
   STACK RENDERING
   ══════════════════════════════════════════════════════════════════ */
.stack-body { display: flex; flex-direction: column; gap: 4px; }

.frame-label {
    font-family: var(--font-mono);
    font-size: 0.63rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    padding: 8px 6px 4px;
    margin-top: 4px;
    border-top: 1px dashed var(--border);
}
.frame-label:first-of-type { border-top: none; margin-top: 0; }
.frame-label .frame-name { color: var(--accent); }

.stack-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 7px 10px;
    border-radius: var(--r-sm);
    border: 1px solid var(--border);
    background: var(--bg-card);
    font-family: var(--font-mono);
    font-size: 0.78rem;
    gap: 10px;
    transition: all 0.2s;
    cursor: default;
    position: relative;
}
.stack-row::before {
    content: '';
    position: absolute;
    left: 0; top: 0; bottom: 0;
    width: 2px;
    border-radius: 2px 0 0 2px;
    background: var(--border-strong);
    transition: background 0.2s;
}
.stack-row.highlighted {
    border-color: var(--border-accent);
    background: var(--accent-glow);
    transform: translateX(3px);
}
.stack-row.highlighted::before { background: var(--accent); }

.stack-var-left { display: flex; align-items: center; gap: 7px; overflow: hidden; }
.var-type   { font-size: 0.66rem; color: var(--color-type); flex-shrink: 0; }
.var-name   { color: var(--text-primary); font-weight: 500; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.var-val    { color: var(--color-val); font-size: 0.76rem; white-space: nowrap; flex-shrink: 0; max-width: 120px; overflow: hidden; text-overflow: ellipsis; }
.var-ref {
    font-size: 0.72rem;
    color: var(--color-ref);
    padding: 2px 7px;
    border-radius: 4px;
    background: rgba(126, 184, 255, 0.07);
    border: 1px solid rgba(126, 184, 255, 0.2);
    cursor: crosshair;
    transition: all 0.2s;
    white-space: nowrap;
    flex-shrink: 0;
}
.var-ref:hover { background: rgba(126, 184, 255, 0.15); border-color: rgba(126, 184, 255, 0.4); box-shadow: 0 0 8px rgba(126, 184, 255, 0.15); }

/* ══════════════════════════════════════════════════════════════════
   HEAP RENDERING
   ══════════════════════════════════════════════════════════════════ */
.heap-body {
    display: flex;
    flex-direction: column;
    gap: 8px;
    overflow-y: auto;
    overflow-x: hidden;
    flex: 1;
    min-height: 0;
    padding: 12px;
    scrollbar-width: thin;
    scrollbar-color: var(--border-strong) transparent;
}
.heap-body::-webkit-scrollbar { width: 6px; }
.heap-body::-webkit-scrollbar-thumb { background: var(--border-strong); border-radius: 3px; }
.heap-body::-webkit-scrollbar-thumb:hover { background: var(--accent); }

.heap-obj {
    background: var(--bg-card);
    border: 1px solid var(--border-strong);
    border-radius: var(--r-md);
    overflow: hidden;
    transition: border-color 0.2s, transform 0.15s, box-shadow 0.2s;
    box-shadow: 0 2px 8px rgba(0,0,0,0.2);
    flex-shrink: 0;
}
.heap-obj:hover { border-color: var(--accent); transform: translateY(-1px); box-shadow: 0 4px 14px rgba(0,0,0,0.3); }
.heap-obj.highlighted { border-color: var(--accent); box-shadow: 0 0 0 1px var(--accent), 0 4px 12px var(--accent-glow); }

.heap-obj-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 9px 12px;
    cursor: pointer;
    user-select: none;
    background: rgba(255, 255, 255, 0.04);
    border-bottom: 1px solid transparent;
    transition: border-color 0.2s;
}
[data-theme="light"] .heap-obj-header { background: rgba(0, 0, 0, 0.03); }
.heap-obj.expanded .heap-obj-header { border-bottom-color: var(--border); }

.heap-obj-type { font-family: var(--font-mono); font-size: 0.76rem; font-weight: 700; color: var(--text-primary); }
[data-theme="light"] .heap-obj-type { color: var(--text-primary); }
.heap-obj-id   { font-family: var(--font-mono); font-size: 0.7rem; color: var(--color-heap-id); opacity: 0.8; flex-shrink: 0; }

.heap-chevron {
    font-size: 0.5rem;
    color: var(--text-muted);
    display: inline-block;
    line-height: 1;
    flex-shrink: 0;
    transition: transform 0.2s var(--ease), color 0.2s;
}
.heap-obj.expanded .heap-chevron { transform: rotate(90deg); color: var(--accent); }

.heap-obj-body { display: none; }
.heap-obj.expanded .heap-obj-body { display: block; }

.heap-field {
    display: grid;
    grid-template-columns: 120px 1fr;
    border-bottom: 1px solid var(--border);
    font-family: var(--font-mono);
    font-size: 0.74rem;
}
.heap-field:last-child { border-bottom: none; }
.heap-field-key {
    padding: 8px 10px;
    background: rgba(255, 255, 255, 0.03);
    border-right: 1px solid var(--border);
    color: var(--text-secondary);
    overflow-wrap: anywhere;
    font-weight: 600;
}
[data-theme="light"] .heap-field-key { background: rgba(0, 0, 0, 0.035); color: var(--text-primary); }
.heap-field-val { padding: 8px 10px; color: var(--color-val); overflow-wrap: anywhere; }
.heap-field-val.is-ref { color: var(--color-ref); font-weight: 600; }

.empty-state {
    color: var(--text-muted);
    font-size: 0.76rem;
    font-family: var(--font-mono);
    padding: 20px 12px;
    text-align: center;
}

/* ══════════════════════════════════════════════════════════════════
   BROWSER RUN PANEL
   ══════════════════════════════════════════════════════════════════ */
.browser-run-panel {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    min-height: 0;
}

/* Preview area (iframe + chrome) */
.browser-preview-wrap {
    flex: 1;
    min-height: 0;
    display: flex;
    flex-direction: column;
    border-bottom: 1px solid var(--border);
}

/* Fake browser chrome bar */
.browser-chrome {
    display: flex;
    align-items: center;
    gap: 7px;
    padding: 7px 12px;
    background: rgba(0, 0, 0, 0.15);
    border-bottom: 1px solid var(--border);
    flex-shrink: 0;
}
[data-theme="light"] .browser-chrome { background: rgba(0, 0, 0, 0.04); }

.browser-dot { width: 10px; height: 10px; border-radius: 50%; flex-shrink: 0; }

.browser-addr {
    flex: 1;
    font-family: var(--font-mono);
    font-size: 0.68rem;
    color: var(--text-muted);
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: 4px;
    padding: 3px 8px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    transition: color 0.3s;
}

.browser-action-btn {
    display: flex;
    align-items: center;
    gap: 5px;
    padding: 4px 10px;
    border-radius: var(--r-sm);
    border: 1px solid var(--border);
    background: var(--bg-card);
    color: var(--text-secondary);
    font-family: var(--font-ui);
    font-size: 0.72rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.18s;
    flex-shrink: 0;
}
.browser-action-btn svg { width: 12px; height: 12px; }
.browser-action-btn:hover { background: var(--accent-dim); color: var(--accent); border-color: var(--border-accent); }
.browser-action-btn:active { transform: scale(0.95); }

/* The live iframe */
.browser-iframe {
    flex: 1;
    width: 100%;
    border: none;
    background: #fff;
    min-height: 0;
    display: block;
}

/* Browser console */
.browser-console-wrap {
    height: 170px;
    min-height: 80px;
    display: flex;
    flex-direction: column;
    flex-shrink: 0;
}

.browser-console-hdr {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 6px 12px;
    border-bottom: 1px solid var(--border);
    background: rgba(0, 0, 0, 0.12);
    font-size: 0.68rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.07em;
    color: var(--text-muted);
    flex-shrink: 0;
}
[data-theme="light"] .browser-console-hdr { background: rgba(0, 0, 0, 0.03); }
.browser-console-hdr svg { width: 11px; height: 11px; }

.browser-clear-btn {
    display: flex;
    align-items: center;
    gap: 4px;
    margin-left: auto;
    padding: 2px 8px;
    border-radius: 4px;
    border: 1px solid var(--border);
    background: transparent;
    color: var(--text-muted);
    font-family: var(--font-ui);
    font-size: 0.67rem;
    cursor: pointer;
    transition: all 0.18s;
}
.browser-clear-btn svg { width: 8px; height: 8px; }
.browser-clear-btn:hover { background: rgba(248,113,113,0.08); border-color: rgba(248,113,113,0.3); color: #f87171; }

.browser-console {
    flex: 1;
    overflow-y: auto;
    padding: 6px 12px;
    font-family: var(--font-mono);
    font-size: 0.76rem;
    line-height: 1.5;
    display: flex;
    flex-direction: column;
    gap: 1px;
    scrollbar-width: thin;
    scrollbar-color: var(--border) transparent;
}
.browser-console::-webkit-scrollbar { width: 5px; }
.browser-console::-webkit-scrollbar-thumb { background: var(--border-strong); border-radius: 3px; }

/* Individual log lines */
.br-log {
    display: flex;
    align-items: flex-start;
    gap: 7px;
    padding: 2px 0;
    border-bottom: 1px solid rgba(255,255,255,0.03);
}
[data-theme="light"] .br-log { border-bottom-color: rgba(0,0,0,0.04); }

.br-log-icon {
    flex-shrink: 0;
    width: 13px;
    font-size: 0.68rem;
    color: var(--text-muted);
    padding-top: 1px;
    text-align: center;
}
.br-log-text { flex: 1; color: var(--text-code); white-space: pre-wrap; word-break: break-all; }

.br-log-warn  .br-log-icon,
.br-log-warn  .br-log-text { color: var(--status-warn); }
.br-log-error .br-log-icon,
.br-log-error .br-log-text { color: var(--status-err); }
.br-log-done  .br-log-text { color: var(--status-ok); }
.br-log-info  .br-log-text { color: var(--text-secondary); }

/* ══════════════════════════════════════════════════════════════════
   UTILITIES
   ══════════════════════════════════════════════════════════════════ */
.hidden { display: none !important; }

/* ══════════════════════════════════════════════════════════════════
   TEMPLATE CONTROL BAR  (html-editor-panel header)
   ══════════════════════════════════════════════════════════════════ */
.template-ctrl-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 10px;
    padding: 7px 12px;
    border-bottom: 1px solid var(--border);
    background: rgba(0, 0, 0, 0.10);
    flex-shrink: 0;
    flex-wrap: wrap;
}
[data-theme="light"] .template-ctrl-bar { background: rgba(0, 0, 0, 0.03); }

/* Scrollable row of ID chips */
.template-ids {
    display: flex;
    align-items: center;
    gap: 4px;
    overflow-x: auto;
    scrollbar-width: none;
    flex: 1;
    min-width: 0;
}
.template-ids::-webkit-scrollbar { display: none; }

.template-ids-label {
    font-size: 0.65rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.07em;
    color: var(--text-muted);
    white-space: nowrap;
    flex-shrink: 0;
    margin-right: 2px;
}

/* Each #id chip */
.template-ids code {
    font-family: var(--font-mono);
    font-size: 0.65rem;
    padding: 2px 6px;
    border-radius: 4px;
    background: var(--accent-glow);
    color: var(--accent);
    border: 1px solid var(--border-accent);
    white-space: nowrap;
    flex-shrink: 0;
    cursor: default;
    transition: background 0.15s;
}
.template-ids code:hover {
    background: var(--accent-dim);
}

/* Default / Custom toggle buttons */
.template-actions {
    display: flex;
    gap: 4px;
    flex-shrink: 0;
}

.tmpl-btn {
    padding: 3px 10px;
    border-radius: 5px;
    border: 1px solid var(--border-strong);
    background: var(--bg-card);
    color: var(--text-muted);
    font-family: var(--font-ui);
    font-size: 0.7rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.18s;
    white-space: nowrap;
}
.tmpl-btn:hover {
    background: var(--bg-panel-hover);
    color: var(--text-primary);
}
.tmpl-btn.tmpl-btn-active {
    background: var(--accent-dim);
    color: var(--accent);
    border-color: var(--border-accent);
}

/* Warning banner — shown in custom mode */
.template-warn {
    display: flex;
    align-items: flex-start;
    gap: 6px;
    padding: 7px 12px;
    background: rgba(251, 191, 36, 0.07);
    border-bottom: 1px solid rgba(251, 191, 36, 0.18);
    color: #fbbf24;
    font-size: 0.72rem;
    font-family: var(--font-mono);
    line-height: 1.4;
    flex-shrink: 0;
}
.template-warn svg { width: 12px; height: 12px; flex-shrink: 0; margin-top: 2px; }

/* Readonly state for default template textarea */
.html-editor-textarea.tmpl-readonly {
    opacity: 0.55;
    cursor: default;
    color: var(--text-muted);
}
.html-editor-textarea.tmpl-readonly:focus { border: none; outline: none; }

/* ══════════════════════════════════════════════════════════════════
   DOCUMENTATION
   ══════════════════════════════════════════════════════════════════ */
.docs-section {
    border-top: 1px solid var(--border);
    padding: 5rem 1.5rem;
}
.docs-wrap { max-width: 1200px; margin: 0 auto; }
.docs-intro { margin-bottom: 3rem; padding-bottom: 2rem; border-bottom: 1px solid var(--border); }
.docs-intro h2 { margin: 0 0 12px; font-size: 1.8rem; font-weight: 800; color: var(--text-primary); letter-spacing: -0.02em; }
.docs-intro p  { margin: 0; color: var(--text-secondary); font-size: 1rem; max-width: 600px; line-height: 1.6; }

.lang-docs       { display: none; animation: fade-up 0.3s var(--ease); }
.lang-docs.active { display: block; }

@keyframes fade-up {
    from { opacity: 0; transform: translateY(8px); }
    to   { opacity: 1; transform: translateY(0); }
}

.docs-layout { display: flex; gap: 3.5rem; align-items: flex-start; }
.docs-nav {
    flex: 0 0 200px;
    position: sticky;
    top: 76px;
}
.docs-nav ul { list-style: none; padding: 0; margin: 0; border-left: 2px solid var(--border); }
.docs-nav a {
    display: block;
    padding: 8px 14px;
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.84rem;
    font-weight: 500;
    border-left: 2px solid transparent;
    margin-left: -2px;
    transition: all 0.18s;
}
.docs-nav a:hover { color: var(--text-primary); border-left-color: var(--accent); background: var(--accent-glow); }

.docs-content { flex: 1; min-width: 0; }
.doc-card { margin-bottom: 3rem; padding: 2rem; border-radius: var(--r-lg); border: 1px solid var(--border); background: var(--bg-panel); backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px); }
.doc-card h3 { margin: 0 0 14px; font-size: 1.1rem; font-weight: 700; color: var(--text-primary); letter-spacing: -0.01em; }
.doc-card p  { margin: 0 0 14px; color: var(--text-secondary); line-height: 1.7; font-size: 0.9rem; }
.doc-card p:last-of-type { margin-bottom: 0; }
.doc-card code { font-family: var(--font-mono); font-size: 0.84em; background: rgba(var(--accent-rgb), 0.08); color: var(--accent); padding: 1px 5px; border-radius: 3px; }
.doc-code { margin: 12px 0; border-radius: var(--r-md); border: 1px solid var(--border); background: var(--bg-input); overflow: hidden; }
.doc-code pre { margin: 0; padding: 12px 14px; overflow-x: auto; }
.doc-code code { background: none; padding: 0; border-radius: 0; color: var(--text-code); font-size: 0.81rem; line-height: 1.6; }
.doc-link { display: inline-flex; align-items: center; gap: 4px; color: var(--accent); text-decoration: none; font-size: 0.84rem; font-weight: 600; margin-top: 10px; transition: filter 0.15s; }
.doc-link:hover { filter: brightness(1.2); text-decoration: underline; text-underline-offset: 3px; }

/* ══════════════════════════════════════════════════════════════════
   FOOTER
   ══════════════════════════════════════════════════════════════════ */
.app-footer { border-top: 1px solid var(--border); padding: 2.5rem 1.5rem; text-align: center; }
.footer-inner { display: flex; flex-direction: column; gap: 4px; }
.footer-brand { margin: 0; font-size: 1rem; font-weight: 700; color: var(--text-secondary); }
.footer-sub   { margin: 0; font-size: 0.75rem; font-family: var(--font-mono); color: var(--text-muted); }
.footer-copy  { margin: 0; font-size: 0.72rem; color: var(--text-muted); opacity: 0.5; }

/* ══════════════════════════════════════════════════════════════════
   SCROLLBARS (global)
   ══════════════════════════════════════════════════════════════════ */
::-webkit-scrollbar        { width: 5px; height: 5px; }
::-webkit-scrollbar-track  { background: transparent; }
::-webkit-scrollbar-thumb  { background: var(--border-strong); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-muted); }

/* ══════════════════════════════════════════════════════════════════
   ANIMATIONS
   ══════════════════════════════════════════════════════════════════ */
@keyframes bounce {
    0%, 80%, 100% { transform: scale(0.7); opacity: 0.4; }
    40%            { transform: scale(1);   opacity: 1; }
}
@keyframes pulse-dot {
    0%, 100% { opacity: 1; }
    50%       { opacity: 0.4; }
}
@keyframes step-flash {
    from { background: var(--accent-dim); }
    to   { background: var(--bg-card); }
}
.stack-row.new-step { animation: step-flash 0.5s var(--ease); }

/* ══════════════════════════════════════════════════════════════════
   RESPONSIVE
   ══════════════════════════════════════════════════════════════════ */
@media (max-width: 1100px) {
    .workspace {
        grid-template-columns: 1fr;
        padding: 1rem;
    }
    .viz-panel {
        height: 70vh;
        min-height: 400px;
    }
}

@media (max-width: 768px) {
    .app-header { padding: 0 1rem; }
    .logo-sub    { display: none; }
    .lang-nav-inner { padding: 0 0.75rem; }
    .lang-pill   { display: none; }
    .workspace   { padding: 0.75rem; gap: 0.75rem; }
    .editor-panel { height: 50vh; }
    .viz-panel   { height: 60vh; }

    .memory-grid {
        grid-template-columns: 1fr;
        grid-template-rows: auto auto;
    }
    .memory-pane {
        border-right: none;
        border-bottom: 1px solid var(--border);
        height: 40vh;
    }
    #arrow-svg { display: none; }

    .viz-toolbar { flex-wrap: wrap; gap: 4px; }
    .toolbar-spacer { display: none; }

    .docs-layout { flex-direction: column; }
    .docs-nav { position: static; width: 100%; flex: none; }
    .docs-nav ul { border-left: none; display: flex; overflow-x: auto; gap: 0; }
    .docs-nav a  { border-left: none; border-bottom: 2px solid transparent; white-space: nowrap; }
    .docs-nav a:hover { border-bottom-color: var(--accent); background: none; }
}