/* ==========================================================================
   THIRD LAW OF THERMODYNAMICS — STYLESHEET
   Dark Engineering & Virtual Physics Lab Theme
   ========================================================================== */

:root {
    /* Color Palette */
    --bg-dark: #0b0f19;
    --bg-card: rgba(19, 27, 46, 0.85);
    --bg-card-border: rgba(0, 240, 255, 0.15);
    --bg-card-hover: rgba(25, 36, 60, 0.95);
    
    --text-main: #e2e8f0;
    --text-muted: #94a3b8;
    --text-bright: #ffffff;
    
    --cyan-glow: #00f0ff;
    --blue-glow: #0088ff;
    --purple-glow: #8b5cf6;
    --amber-glow: #f59e0b;
    --red-glow: #ef4444;
    --emerald-glow: #10b981;
    --ice-cyan: #d0f7ff;

    /* Fonts */
    --font-main: 'Inter', system-ui, -apple-system, sans-serif;
    --font-title: 'Outfit', system-ui, sans-serif;
    --font-mono: 'JetBrains Mono', monospace;

    /* Transitions & Shadows */
    --transition-fast: 0.15s ease;
    --transition-med: 0.25s ease;
    --card-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
    --glow-shadow-cyan: 0 0 15px rgba(0, 240, 255, 0.3);
    --glow-shadow-blue: 0 0 15px rgba(0, 136, 255, 0.3);
}

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

body {
    background-color: var(--bg-dark);
    background-image: 
        radial-gradient(circle at 15% 15%, rgba(0, 240, 255, 0.05) 0%, transparent 40%),
        radial-gradient(circle at 85% 85%, rgba(139, 92, 246, 0.05) 0%, transparent 40%),
        linear-gradient(rgba(255, 255, 255, 0.02) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 255, 255, 0.02) 1px, transparent 1px);
    background-size: 100% 100%, 100% 100%, 30px 30px, 30px 30px;
    color: var(--text-main);
    font-family: var(--font-main);
    line-height: 1.5;
    min-height: 100vh;
    padding: 1.5rem;
}

.app-container {
    max-width: 1600px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

/* ==========================================================================
   HEADER SECTION
   ========================================================================== */
.app-header {
    background: var(--bg-card);
    border: 1px solid var(--bg-card-border);
    backdrop-filter: blur(12px);
    border-radius: 16px;
    padding: 1.25rem 1.75rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 1rem;
    box-shadow: var(--card-shadow);
}

.brand {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.brand-icon {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, rgba(0, 240, 255, 0.2), rgba(0, 136, 255, 0.3));
    border: 1px solid var(--cyan-glow);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--cyan-glow);
    box-shadow: var(--glow-shadow-cyan);
}

.brand-text h1 {
    font-family: var(--font-title);
    font-size: 1.4rem;
    font-weight: 800;
    letter-spacing: 0.5px;
    color: var(--text-bright);
    background: linear-gradient(90deg, #ffffff, var(--cyan-glow));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.subtitle {
    font-size: 0.75rem;
    font-family: var(--font-mono);
    color: var(--text-muted);
    letter-spacing: 1px;
}

.law-statement-badge {
    display: flex;
    flex-direction: column;
    align-items: center;
    background: rgba(0, 240, 255, 0.06);
    border: 1px solid rgba(0, 240, 255, 0.25);
    border-radius: 12px;
    padding: 0.5rem 1.25rem;
}

.badge-label {
    font-size: 0.65rem;
    font-family: var(--font-mono);
    color: var(--cyan-glow);
    letter-spacing: 1.5px;
    font-weight: 700;
}

.badge-formula {
    font-family: var(--font-mono);
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--text-bright);
}

.badge-desc {
    font-size: 0.7rem;
    color: var(--text-muted);
}

.header-status {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    font-size: 0.85rem;
    font-family: var(--font-mono);
    background: rgba(16, 185, 129, 0.1);
    border: 1px solid rgba(16, 185, 129, 0.3);
    padding: 0.4rem 0.8rem;
    border-radius: 20px;
    color: var(--emerald-glow);
}

.status-indicator {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--emerald-glow);
    box-shadow: 0 0 10px var(--emerald-glow);
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; transform: scale(1); }
    50% { opacity: 0.4; transform: scale(0.85); }
}

/* ==========================================================================
   CARDS & DASHBOARD GRID
   ========================================================================== */
.dashboard-grid {
    display: grid;
    grid-template-columns: 1fr 480px;
    gap: 1.5rem;
}

@media (max-width: 1200px) {
    .dashboard-grid {
        grid-template-columns: 1fr;
    }
}

.card {
    background: var(--bg-card);
    border: 1px solid var(--bg-card-border);
    backdrop-filter: blur(12px);
    border-radius: 16px;
    padding: 1.25rem;
    box-shadow: var(--card-shadow);
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.card-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-bottom: 0.75rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

.card-title {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    font-family: var(--font-title);
    font-weight: 700;
    font-size: 1rem;
    color: var(--text-bright);
}

.card-title svg {
    color: var(--cyan-glow);
}

/* ==========================================================================
   VISUALIZER COLUMN (LEFT)
   ========================================================================== */
.visualizer-column {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.canvas-wrapper {
    position: relative;
    width: 100%;
    background: rgba(5, 8, 15, 0.9);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 12px;
    overflow: hidden;
}

#latticeCanvas {
    width: 100%;
    height: 340px;
    display: block;
}

#graphCanvas {
    width: 100%;
    height: 240px;
    display: block;
}

#stepsCanvas {
    width: 100%;
    height: 180px;
    display: block;
}

.chamber-controls {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.toggle-switch {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    cursor: pointer;
}

.toggle-switch input {
    display: none;
}

.slider {
    position: relative;
    width: 34px;
    height: 18px;
    background-color: #334155;
    border-radius: 18px;
    transition: var(--transition-fast);
}

.slider:before {
    position: absolute;
    content: "";
    height: 12px;
    width: 12px;
    left: 3px;
    bottom: 3px;
    background-color: white;
    border-radius: 50%;
    transition: var(--transition-fast);
}

input:checked + .slider {
    background-color: var(--cyan-glow);
}

input:checked + .slider:before {
    transform: translateX(16px);
}

.toggle-label {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.chamber-overlay-badge {
    position: absolute;
    top: 12px;
    left: 12px;
    background: rgba(11, 15, 25, 0.85);
    border: 1px solid rgba(0, 240, 255, 0.3);
    border-radius: 8px;
    padding: 0.4rem 0.8rem;
    pointer-events: none;
}

.overlay-temp {
    font-family: var(--font-mono);
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--cyan-glow);
}

.overlay-state {
    font-size: 0.7rem;
    color: var(--text-muted);
}

.quantum-disclaimer {
    position: absolute;
    bottom: 10px;
    left: 10px;
    right: 10px;
    background: rgba(139, 92, 246, 0.12);
    border: 1px solid rgba(139, 92, 246, 0.35);
    border-radius: 8px;
    padding: 0.5rem 0.8rem;
    display: flex;
    align-items: center;
    gap: 0.6rem;
    font-size: 0.73rem;
    color: #d8b4fe;
    backdrop-filter: blur(4px);
    transition: opacity 0.3s ease;
}

.qd-icon {
    font-weight: 800;
    font-size: 0.9rem;
    background: rgba(139, 92, 246, 0.3);
    width: 20px;
    height: 20px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.graph-options {
    display: flex;
    gap: 0.5rem;
}

.btn-sm {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.15);
    color: var(--text-main);
    padding: 0.3rem 0.6rem;
    border-radius: 6px;
    font-size: 0.72rem;
    font-family: var(--font-main);
    cursor: pointer;
    transition: var(--transition-fast);
}

.btn-sm:hover {
    background: rgba(255, 255, 255, 0.12);
}

.btn-sm.active {
    background: rgba(0, 240, 255, 0.15);
    border-color: var(--cyan-glow);
    color: var(--cyan-glow);
    font-weight: 600;
}

/* Cooling Steps visualizer */
.cooling-steps-body {
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
}

.steps-canvas-wrapper {
    background: rgba(5, 8, 15, 0.9);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 10px;
    overflow: hidden;
}

.steps-control-bar {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    flex-wrap: wrap;
}

.steps-info-badge {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--text-muted);
}

.steps-info-badge strong {
    color: var(--cyan-glow);
}

.steps-explanation {
    font-size: 0.73rem;
    color: var(--text-muted);
    width: 100%;
    margin-top: 0.2rem;
}

/* ==========================================================================
   TELEMETRY & CONTROLS COLUMN (RIGHT)
   ========================================================================== */
.controls-column {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.readout-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0.75rem;
}

.readout-item {
    background: rgba(15, 23, 42, 0.7);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 12px;
    padding: 0.8rem 1rem;
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
    transition: var(--transition-fast);
}

.readout-item:hover {
    border-color: rgba(255, 255, 255, 0.2);
}

.readout-label {
    font-size: 0.65rem;
    font-family: var(--font-mono);
    color: var(--text-muted);
    letter-spacing: 0.5px;
    font-weight: 600;
}

.readout-value {
    font-family: var(--font-mono);
    font-size: 1.35rem;
    font-weight: 700;
    color: var(--text-bright);
}

.readout-value .unit {
    font-size: 0.75rem;
    color: var(--text-muted);
    font-weight: 400;
}

.readout-sub {
    font-size: 0.72rem;
    color: var(--text-muted);
}

.glow-cyan .readout-value { color: var(--cyan-glow); }
.glow-blue .readout-value { color: var(--blue-glow); }
.glow-amber .readout-value { color: var(--amber-glow); }
.glow-purple .readout-value { color: #c084fc; }

/* Absolute Zero Alert Banner */
.abs-zero-banner {
    margin-top: 0.75rem;
    background: linear-gradient(90deg, rgba(0, 240, 255, 0.1), rgba(0, 136, 255, 0.15));
    border: 1px solid var(--cyan-glow);
    border-radius: 12px;
    padding: 0.8rem 1rem;
    display: flex;
    align-items: center;
    gap: 1rem;
    box-shadow: var(--glow-shadow-cyan);
    transition: all 0.3s ease;
}

.abs-zero-banner.highlight-active {
    background: linear-gradient(90deg, rgba(139, 92, 246, 0.2), rgba(0, 240, 255, 0.25));
    border-color: #a855f7;
    animation: bannerGlow 1.5s infinite alternate;
}

@keyframes bannerGlow {
    from { box-shadow: 0 0 10px rgba(168, 85, 247, 0.4); }
    to { box-shadow: 0 0 25px rgba(0, 240, 255, 0.7); }
}

.az-icon {
    color: var(--cyan-glow);
    display: flex;
    align-items: center;
}

.az-title {
    font-family: var(--font-title);
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--text-bright);
}

.az-desc {
    font-size: 0.72rem;
    color: var(--text-muted);
}

/* Controls Card */
.control-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.slider-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.8rem;
    color: var(--text-main);
}

.slider-val-box {
    font-family: var(--font-mono);
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--cyan-glow);
    background: rgba(0, 240, 255, 0.08);
    border: 1px solid rgba(0, 240, 255, 0.2);
    padding: 0.15rem 0.6rem;
    border-radius: 6px;
}

input[type=range] {
    -webkit-appearance: none;
    width: 100%;
    height: 8px;
    border-radius: 4px;
    background: linear-gradient(90deg, var(--purple-glow) 0%, var(--cyan-glow) 30%, var(--amber-glow) 100%);
    outline: none;
}

input[type=range]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 22px;
    height: 22px;
    border-radius: 50%;
    background: var(--text-bright);
    border: 2px solid var(--cyan-glow);
    cursor: pointer;
    box-shadow: 0 0 10px var(--cyan-glow);
    transition: transform 0.1s ease;
}

input[type=range]::-webkit-slider-thumb:hover {
    transform: scale(1.15);
}

.temp-scale-ticks {
    display: flex;
    justify-content: space-between;
    font-size: 0.65rem;
    font-family: var(--font-mono);
    color: var(--text-muted);
    padding: 0 2px;
}

.temp-scale-ticks .tick {
    cursor: pointer;
    transition: color 0.15s ease;
}

.temp-scale-ticks .tick:hover,
.temp-scale-ticks .tick.active {
    color: var(--cyan-glow);
    font-weight: 700;
}

/* Fine adjustment bar */
.fine-adjust-bar {
    display: flex;
    gap: 0.4rem;
}

.btn-step {
    flex: 1;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(255, 255, 255, 0.12);
    color: var(--text-main);
    padding: 0.35rem 0;
    border-radius: 6px;
    font-size: 0.72rem;
    font-family: var(--font-mono);
    cursor: pointer;
    transition: var(--transition-fast);
}

.btn-step:hover {
    background: rgba(0, 240, 255, 0.12);
    border-color: var(--cyan-glow);
    color: var(--cyan-glow);
}

/* Presets Grid */
.section-label {
    font-size: 0.65rem;
    font-family: var(--font-mono);
    color: var(--text-muted);
    letter-spacing: 1px;
    font-weight: 700;
}

.presets-section {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.presets-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 0.4rem;
}

.btn-preset {
    background: rgba(15, 23, 42, 0.8);
    border: 1px solid rgba(255, 255, 255, 0.1);
    color: var(--text-main);
    padding: 0.4rem 0.3rem;
    border-radius: 8px;
    font-size: 0.68rem;
    font-family: var(--font-main);
    cursor: pointer;
    text-align: center;
    transition: var(--transition-fast);
}

.btn-preset:hover {
    background: rgba(0, 240, 255, 0.1);
    border-color: rgba(0, 240, 255, 0.4);
    color: var(--text-bright);
}

.btn-preset.active {
    background: rgba(0, 240, 255, 0.2);
    border-color: var(--cyan-glow);
    color: var(--cyan-glow);
    font-weight: 600;
}

.btn-preset.highlight-zero {
    border-color: rgba(168, 85, 247, 0.6);
    background: rgba(168, 85, 247, 0.15);
    color: #e9d5ff;
}

.btn-preset.highlight-zero:hover {
    background: rgba(168, 85, 247, 0.3);
    color: var(--text-bright);
}

/* Automated cooling panel */
.auto-cooling-panel {
    display: flex;
    flex-direction: column;
    gap: 0.6rem;
    background: rgba(10, 15, 25, 0.6);
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-radius: 12px;
    padding: 0.8rem;
}

.action-buttons {
    display: flex;
    gap: 0.5rem;
}

.btn {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.4rem;
    padding: 0.55rem 0.8rem;
    border-radius: 8px;
    font-size: 0.78rem;
    font-family: var(--font-main);
    font-weight: 600;
    cursor: pointer;
    border: 1px solid transparent;
    transition: var(--transition-fast);
}

.btn-primary {
    background: linear-gradient(135deg, #0088ff, #00f0ff);
    color: #0b0f19;
    font-weight: 700;
}

.btn-primary:hover {
    box-shadow: var(--glow-shadow-cyan);
    transform: translateY(-1px);
}

.btn-success {
    background: linear-gradient(135deg, #059669, #10b981);
    color: #ffffff;
}

.btn-success:hover {
    box-shadow: 0 0 12px rgba(16, 185, 129, 0.4);
}

.btn-warning {
    background: rgba(245, 158, 11, 0.2);
    border-color: var(--amber-glow);
    color: var(--amber-glow);
}

.btn-warning:hover:not(:disabled) {
    background: rgba(245, 158, 11, 0.35);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.08);
    border-color: rgba(255, 255, 255, 0.15);
    color: var(--text-main);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.15);
}

.btn-outline {
    background: transparent;
    border-color: rgba(255, 255, 255, 0.2);
    color: var(--text-muted);
}

.btn-outline:hover {
    border-color: var(--cyan-glow);
    color: var(--cyan-glow);
}

.btn:disabled {
    opacity: 0.4;
    cursor: not-allowed;
    transform: none !important;
    box-shadow: none !important;
}

.rate-selector {
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 0.75rem;
    color: var(--text-muted);
}

.rate-selector select {
    background: rgba(15, 23, 42, 0.9);
    border: 1px solid rgba(255, 255, 255, 0.15);
    color: var(--text-bright);
    border-radius: 6px;
    padding: 0.2rem 0.5rem;
    font-size: 0.75rem;
    outline: none;
}

/* State Monitor Card */
.state-monitor-body {
    display: flex;
    flex-direction: column;
    gap: 0.45rem;
}

.state-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.75rem;
    padding: 0.25rem 0;
    border-bottom: 1px dashed rgba(255, 255, 255, 0.06);
}

.state-row:last-child {
    border-bottom: none;
}

.state-key {
    color: var(--text-muted);
}

.state-val {
    font-family: var(--font-mono);
    font-weight: 600;
    color: var(--text-bright);
}

.trend-stable { color: var(--cyan-glow); }
.trend-decreasing { color: var(--blue-glow); }

/* ==========================================================================
   OBSERVATION TABLE SECTION
   ========================================================================== */
.table-section {
    width: 100%;
}

.table-actions {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.table-responsive {
    width: 100%;
    overflow-x: auto;
    max-height: 280px;
}

.obs-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.78rem;
    text-align: left;
}

.obs-table th {
    position: sticky;
    top: 0;
    background: #0f172a;
    color: var(--cyan-glow);
    font-family: var(--font-mono);
    font-weight: 600;
    padding: 0.6rem 0.8rem;
    border-bottom: 1px solid rgba(0, 240, 255, 0.2);
}

.obs-table td {
    padding: 0.55rem 0.8rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.04);
    color: var(--text-main);
    font-family: var(--font-mono);
}

.obs-table tbody tr:hover {
    background: rgba(0, 240, 255, 0.05);
}

/* ==========================================================================
   EDUCATIONAL MODULE TABS
   ========================================================================== */
.edu-section {
    width: 100%;
}

.tab-buttons {
    display: flex;
    gap: 0.4rem;
    flex-wrap: wrap;
}

.tab-btn {
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(255, 255, 255, 0.1);
    color: var(--text-muted);
    padding: 0.4rem 0.8rem;
    border-radius: 8px;
    font-size: 0.75rem;
    font-family: var(--font-main);
    cursor: pointer;
    transition: var(--transition-fast);
}

.tab-btn:hover {
    color: var(--text-bright);
    background: rgba(255, 255, 255, 0.08);
}

.tab-btn.active {
    background: rgba(0, 240, 255, 0.15);
    border-color: var(--cyan-glow);
    color: var(--cyan-glow);
    font-weight: 600;
}

.tab-content-container {
    padding-top: 0.5rem;
}

.tab-pane {
    display: none;
}

.tab-pane.active {
    display: block;
}

.edu-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.25rem;
}

@media (max-width: 900px) {
    .edu-grid {
        grid-template-columns: 1fr;
    }
}

.edu-card {
    background: rgba(10, 15, 25, 0.6);
    border: 1px solid rgba(255, 255, 255, 0.06);
    border-radius: 12px;
    padding: 1.2rem;
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
}

.edu-card h3 {
    font-family: var(--font-title);
    font-size: 1.05rem;
    color: var(--text-bright);
    border-bottom: 1px solid rgba(0, 240, 255, 0.2);
    padding-bottom: 0.4rem;
}

.edu-card h4 {
    font-size: 0.9rem;
    color: var(--cyan-glow);
    margin-top: 0.4rem;
}

.edu-card p {
    font-size: 0.82rem;
    color: var(--text-main);
    line-height: 1.6;
}

.edu-card ul {
    padding-left: 1.2rem;
    font-size: 0.82rem;
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
}

.formula-box {
    background: rgba(5, 8, 15, 0.9);
    border: 1px solid rgba(0, 240, 255, 0.25);
    border-radius: 8px;
    padding: 0.75rem;
    text-align: center;
    font-family: var(--font-mono);
    font-size: 0.95rem;
    color: var(--cyan-glow);
    font-weight: 600;
}

.quote-box {
    background: rgba(139, 92, 246, 0.1);
    border-left: 3px solid var(--purple-glow);
    padding: 0.75rem 1rem;
    font-style: italic;
    font-size: 0.82rem;
    color: #e9d5ff;
    border-radius: 0 8px 8px 0;
}

.edu-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.75rem;
}

.edu-table th {
    background: rgba(0, 240, 255, 0.1);
    color: var(--cyan-glow);
    padding: 0.5rem;
    border-bottom: 1px solid rgba(0, 240, 255, 0.2);
    text-align: left;
}

.edu-table td {
    padding: 0.45rem 0.5rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.steps-flow {
    display: flex;
    flex-direction: column;
    gap: 0.6rem;
}

.flow-step {
    background: rgba(15, 23, 42, 0.8);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 8px;
    padding: 0.6rem 0.8rem;
    display: flex;
    gap: 0.8rem;
    align-items: flex-start;
}

.step-num {
    background: rgba(0, 240, 255, 0.2);
    color: var(--cyan-glow);
    font-family: var(--font-mono);
    font-size: 0.7rem;
    font-weight: 700;
    padding: 0.2rem 0.5rem;
    border-radius: 4px;
    flex-shrink: 0;
}

.step-desc {
    font-size: 0.78rem;
    color: var(--text-main);
}

/* Quiz & Calculator */
.quiz-question {
    font-family: var(--font-title);
    font-weight: 600;
    font-size: 0.92rem;
    color: var(--text-bright);
}

.quiz-options {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;

}

.quiz-opt-btn {
    background: rgba(15, 23, 42, 0.9);
    border: 1px solid rgba(255, 255, 255, 0.12);
    color: var(--text-main);
    padding: 0.6rem 0.8rem;
    border-radius: 8px;
    font-size: 0.8rem;
    text-align: left;
    cursor: pointer;
    transition: var(--transition-fast);
}

.quiz-opt-btn:hover {
    border-color: var(--cyan-glow);
    background: rgba(0, 240, 255, 0.08);
}

.quiz-opt-btn.correct {
    background: rgba(16, 185, 129, 0.2);
    border-color: var(--emerald-glow);
    color: #6ee7b7;
}

.quiz-opt-btn.wrong {
    background: rgba(239, 68, 68, 0.2);
    border-color: var(--red-glow);
    color: #fca5a5;
}

.quiz-feedback {
    font-size: 0.8rem;
    min-height: 24px;
    font-weight: 600;
}

.quiz-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 0.5rem;
}

.quiz-score {
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--cyan-glow);
}

.calc-group {
    display: flex;
    flex-direction: column;
    gap: 0.3rem;
    font-size: 0.8rem;
}

.calc-input {
    background: rgba(15, 23, 42, 0.9);
    border: 1px solid rgba(255, 255, 255, 0.15);
    color: var(--cyan-glow);
    font-family: var(--font-mono);
    border-radius: 6px;
    padding: 0.4rem 0.6rem;
    font-size: 0.85rem;
    outline: none;
}

.calc-result {
    background: rgba(0, 240, 255, 0.08);
    border: 1px solid rgba(0, 240, 255, 0.25);
    border-radius: 8px;
    padding: 0.6rem 0.8rem;
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--cyan-glow);
    font-weight: 600;
}

/* ==========================================================================
   FOOTER
   ========================================================================== */
.app-footer {
    text-align: center;
    padding: 1.5rem 0;
    border-top: 1px solid rgba(255, 255, 255, 0.06);
    font-size: 0.78rem;
    color: var(--text-muted);
    display: flex;
    flex-direction: column;
    gap: 0.2rem;
}

.footer-note {
    font-size: 0.7rem;
    color: rgba(255, 255, 255, 0.3);
}

/* ==========================================================================
   THIRD LAW OF THERMODYNAMICS — LIGHT THEME SYSTEM OVERRIDES
   ========================================================================== */
html[data-theme="light"],
html:not(.dark):not([data-theme="dark"]) {
    --bg-dark: #f8fafc;
    --bg-card: #ffffff;
    --bg-card-border: #e2e8f0;
    --bg-card-hover: #f1f5f9;
    
    --text-main: #0f172a;
    --text-muted: #475569;
    --text-bright: #0f172a;
    
    --cyan-glow: #0284c7;
    --blue-glow: #2563eb;
    --purple-glow: #9333ea;
    --amber-glow: #d97706;
    --red-glow: #dc2626;
    --emerald-glow: #16a34a;
    --ice-cyan: #0284c7;

    --card-shadow: 0 1px 3px rgba(0, 0, 0, 0.04), 0 4px 12px rgba(15, 23, 42, 0.03);
    --glow-shadow-cyan: 0 0 15px rgba(2, 132, 199, 0.15);
    --glow-shadow-blue: 0 0 15px rgba(37, 99, 235, 0.15);
}

html[data-theme="light"] body,
html:not(.dark):not([data-theme="dark"]) body {
    background-color: #f8fafc;
    background-image: 
        radial-gradient(circle at 15% 15%, rgba(2, 132, 199, 0.04) 0%, transparent 40%),
        radial-gradient(circle at 85% 85%, rgba(147, 51, 234, 0.04) 0%, transparent 40%),
        linear-gradient(rgba(15, 23, 42, 0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(15, 23, 42, 0.03) 1px, transparent 1px);
    color: #0f172a;
}

html[data-theme="light"] .app-header,
html:not(.dark):not([data-theme="dark"]) .app-header {
    background: #ffffff;
    border-color: #e2e8f0;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.04), 0 4px 12px rgba(15, 23, 42, 0.03);
}

html[data-theme="light"] .brand-icon,
html:not(.dark):not([data-theme="dark"]) .brand-icon {
    background: #e0f2fe;
    border-color: #0284c7;
    color: #0284c7;
    box-shadow: none;
}

html[data-theme="light"] .brand-text h1,
html:not(.dark):not([data-theme="dark"]) .brand-text h1 {
    color: #0f172a !important;
    background: none !important;
    -webkit-text-fill-color: #0f172a !important;
}

html[data-theme="light"] .subtitle,
html:not(.dark):not([data-theme="dark"]) .subtitle {
    color: #64748b;
}

html[data-theme="light"] .law-statement-badge,
html:not(.dark):not([data-theme="dark"]) .law-statement-badge {
    background: #f0f9ff;
    border-color: #bae6fd;
}

html[data-theme="light"] .badge-label,
html:not(.dark):not([data-theme="dark"]) .badge-label {
    color: #0284c7;
}

html[data-theme="light"] .badge-formula,
html:not(.dark):not([data-theme="dark"]) .badge-formula {
    color: #0f172a;
}

html[data-theme="light"] .badge-desc,
html:not(.dark):not([data-theme="dark"]) .badge-desc {
    color: #64748b;
}

html[data-theme="light"] .header-status,
html:not(.dark):not([data-theme="dark"]) .header-status {
    background: #f0fdf4;
    border-color: #bbf7d0;
    color: #16a34a;
}

html[data-theme="light"] .card,
html:not(.dark):not([data-theme="dark"]) .card {
    background: #ffffff;
    border-color: #e2e8f0;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.04), 0 4px 12px rgba(15, 23, 42, 0.03);
}

html[data-theme="light"] .card-header,
html:not(.dark):not([data-theme="dark"]) .card-header {
    border-bottom-color: #e2e8f0;
}

html[data-theme="light"] .card-title,
html:not(.dark):not([data-theme="dark"]) .card-title {
    color: #0f172a;
}

html[data-theme="light"] .card-title svg,
html:not(.dark):not([data-theme="dark"]) .card-title svg {
    color: #0284c7;
}

html[data-theme="light"] .canvas-wrapper,
html:not(.dark):not([data-theme="dark"]) .canvas-wrapper,
html[data-theme="light"] .steps-canvas-wrapper,
html:not(.dark):not([data-theme="dark"]) .steps-canvas-wrapper {
    background: #f8fafc;
    border-color: #e2e8f0;
}

html[data-theme="light"] .chamber-overlay-badge,
html:not(.dark):not([data-theme="dark"]) .chamber-overlay-badge {
    background: rgba(255, 255, 255, 0.95);
    border-color: #bae6fd;
    box-shadow: 0 4px 12px rgba(15, 23, 42, 0.08);
}

html[data-theme="light"] .overlay-temp,
html:not(.dark):not([data-theme="dark"]) .overlay-temp {
    color: #0284c7;
}

html[data-theme="light"] .overlay-state,
html:not(.dark):not([data-theme="dark"]) .overlay-state {
    color: #475569;
}

html[data-theme="light"] .quantum-disclaimer,
html:not(.dark):not([data-theme="dark"]) .quantum-disclaimer {
    background: rgba(243, 232, 255, 0.95);
    border-color: #d8b4fe;
    color: #6b21a8;
}

html[data-theme="light"] .qd-icon,
html:not(.dark):not([data-theme="dark"]) .qd-icon {
    background: #c084fc;
    color: #ffffff;
}

html[data-theme="light"] .toggle-label,
html:not(.dark):not([data-theme="dark"]) .toggle-label {
    color: #475569;
}

html[data-theme="light"] .slider,
html:not(.dark):not([data-theme="dark"]) .slider {
    background-color: #cbd5e1;
}

html[data-theme="light"] input:checked + .slider,
html:not(.dark):not([data-theme="dark"]) input:checked + .slider {
    background-color: #0284c7;
}

html[data-theme="light"] .readout-item,
html:not(.dark):not([data-theme="dark"]) .readout-item {
    background: #f8fafc;
    border-color: #e2e8f0;
}

html[data-theme="light"] .readout-item:hover,
html:not(.dark):not([data-theme="dark"]) .readout-item:hover {
    background: #f1f5f9;
    border-color: #cbd5e1;
}

html[data-theme="light"] .readout-label,
html:not(.dark):not([data-theme="dark"]) .readout-label {
    color: #64748b;
}

html[data-theme="light"] .readout-value,
html:not(.dark):not([data-theme="dark"]) .readout-value {
    color: #0f172a;
}

html[data-theme="light"] .readout-value .unit,
html:not(.dark):not([data-theme="dark"]) .readout-value .unit {
    color: #64748b;
}

html[data-theme="light"] .readout-sub,
html:not(.dark):not([data-theme="dark"]) .readout-sub {
    color: #64748b;
}

html[data-theme="light"] .glow-cyan .readout-value,
html:not(.dark):not([data-theme="dark"]) .glow-cyan .readout-value { color: #0284c7; }
html[data-theme="light"] .glow-blue .readout-value,
html:not(.dark):not([data-theme="dark"]) .glow-blue .readout-value { color: #2563eb; }
html[data-theme="light"] .glow-amber .readout-value,
html:not(.dark):not([data-theme="dark"]) .glow-amber .readout-value { color: #d97706; }
html[data-theme="light"] .glow-purple .readout-value,
html:not(.dark):not([data-theme="dark"]) .glow-purple .readout-value { color: #9333ea; }

html[data-theme="light"] .abs-zero-banner,
html:not(.dark):not([data-theme="dark"]) .abs-zero-banner {
    background: linear-gradient(90deg, #e0f2fe, #f0fdf4);
    border-color: #38bdf8;
    box-shadow: 0 2px 8px rgba(14, 165, 233, 0.12);
}

html[data-theme="light"] .az-icon,
html:not(.dark):not([data-theme="dark"]) .az-icon {
    color: #0284c7;
}

html[data-theme="light"] .az-title,
html:not(.dark):not([data-theme="dark"]) .az-title {
    color: #0369a1;
}

html[data-theme="light"] .az-desc,
html:not(.dark):not([data-theme="dark"]) .az-desc {
    color: #475569;
}

html[data-theme="light"] .slider-header,
html:not(.dark):not([data-theme="dark"]) .slider-header {
    color: #0f172a;
}

html[data-theme="light"] .slider-val-box,
html:not(.dark):not([data-theme="dark"]) .slider-val-box {
    background: #e0f2fe;
    border-color: #bae6fd;
    color: #0369a1;
}

html[data-theme="light"] .temp-scale-ticks,
html:not(.dark):not([data-theme="dark"]) .temp-scale-ticks {
    color: #64748b;
}

html[data-theme="light"] .temp-scale-ticks .tick:hover,
html[data-theme="light"] .temp-scale-ticks .tick.active,
html:not(.dark):not([data-theme="dark"]) .temp-scale-ticks .tick:hover,
html:not(.dark):not([data-theme="dark"]) .temp-scale-ticks .tick.active {
    color: #0284c7;
}

html[data-theme="light"] .btn-step,
html:not(.dark):not([data-theme="dark"]) .btn-step {
    background: #ffffff;
    border-color: #e2e8f0;
    color: #334155;
}

html[data-theme="light"] .btn-step:hover,
html:not(.dark):not([data-theme="dark"]) .btn-step:hover {
    background: #f1f5f9;
    border-color: #0284c7;
    color: #0284c7;
}

html[data-theme="light"] .section-label,
html:not(.dark):not([data-theme="dark"]) .section-label {
    color: #64748b;
}

html[data-theme="light"] .btn-preset,
html:not(.dark):not([data-theme="dark"]) .btn-preset {
    background: #ffffff;
    border-color: #e2e8f0;
    color: #475569;
}

html[data-theme="light"] .btn-preset:hover,
html:not(.dark):not([data-theme="dark"]) .btn-preset:hover {
    background: #f1f5f9;
    border-color: #cbd5e1;
    color: #0f172a;
}

html[data-theme="light"] .btn-preset.active,
html:not(.dark):not([data-theme="dark"]) .btn-preset.active {
    background: #e0f2fe;
    border-color: #0284c7;
    color: #0284c7;
}

html[data-theme="light"] .btn-preset.highlight-zero,
html:not(.dark):not([data-theme="dark"]) .btn-preset.highlight-zero {
    background: #f3e8ff;
    border-color: #c084fc;
    color: #7e22ce;
}

html[data-theme="light"] .btn-preset.highlight-zero:hover,
html:not(.dark):not([data-theme="dark"]) .btn-preset.highlight-zero:hover {
    background: #e9d5ff;
    color: #581c87;
}

html[data-theme="light"] .auto-cooling-panel,
html:not(.dark):not([data-theme="dark"]) .auto-cooling-panel {
    background: #f8fafc;
    border-color: #e2e8f0;
}

html[data-theme="light"] .btn-secondary,
html:not(.dark):not([data-theme="dark"]) .btn-secondary {
    background: #ffffff;
    border-color: #e2e8f0;
    color: #334155;
}

html[data-theme="light"] .btn-secondary:hover,
html:not(.dark):not([data-theme="dark"]) .btn-secondary:hover {
    background: #f1f5f9;
    color: #0f172a;
}

html[data-theme="light"] .btn-outline,
html:not(.dark):not([data-theme="dark"]) .btn-outline {
    background: transparent;
    border-color: #cbd5e1;
    color: #475569;
}

html[data-theme="light"] .btn-outline:hover,
html:not(.dark):not([data-theme="dark"]) .btn-outline:hover {
    border-color: #0284c7;
    color: #0284c7;
}

html[data-theme="light"] .rate-selector select,
html:not(.dark):not([data-theme="dark"]) .rate-selector select {
    background: #ffffff;
    border-color: #cbd5e1;
    color: #0f172a;
}

html[data-theme="light"] .state-row,
html:not(.dark):not([data-theme="dark"]) .state-row {
    border-bottom-color: #e2e8f0;
}

html[data-theme="light"] .state-key,
html:not(.dark):not([data-theme="dark"]) .state-key {
    color: #64748b;
}

html[data-theme="light"] .state-val,
html:not(.dark):not([data-theme="dark"]) .state-val {
    color: #0f172a;
}

html[data-theme="light"] .btn-sm,
html:not(.dark):not([data-theme="dark"]) .btn-sm {
    background: #ffffff;
    border-color: #e2e8f0;
    color: #475569;
}

html[data-theme="light"] .btn-sm:hover,
html:not(.dark):not([data-theme="dark"]) .btn-sm:hover {
    background: #f1f5f9;
    color: #0f172a;
}

html[data-theme="light"] .btn-sm.active,
html:not(.dark):not([data-theme="dark"]) .btn-sm.active {
    background: #e0f2fe;
    border-color: #0284c7;
    color: #0284c7;
}

html[data-theme="light"] .obs-table th,
html:not(.dark):not([data-theme="dark"]) .obs-table th {
    background: #f1f5f9;
    color: #0369a1;
    border-bottom-color: #e2e8f0;
}

html[data-theme="light"] .obs-table td,
html:not(.dark):not([data-theme="dark"]) .obs-table td {
    color: #334155;
    border-bottom-color: #e2e8f0;
}

html[data-theme="light"] .obs-table tbody tr:hover,
html:not(.dark):not([data-theme="dark"]) .obs-table tbody tr:hover {
    background: #f8fafc;
}

html[data-theme="light"] .tab-btn,
html:not(.dark):not([data-theme="dark"]) .tab-btn {
    background: #ffffff;
    border-color: #e2e8f0;
    color: #64748b;
}

html[data-theme="light"] .tab-btn:hover,
html:not(.dark):not([data-theme="dark"]) .tab-btn:hover {
    background: #f1f5f9;
    color: #0f172a;
}

html[data-theme="light"] .tab-btn.active,
html:not(.dark):not([data-theme="dark"]) .tab-btn.active {
    background: #e0f2fe;
    border-color: #0284c7;
    color: #0284c7;
}

html[data-theme="light"] .edu-card,
html:not(.dark):not([data-theme="dark"]) .edu-card {
    background: #ffffff;
    border-color: #e2e8f0;
}

html[data-theme="light"] .edu-card h3,
html:not(.dark):not([data-theme="dark"]) .edu-card h3 {
    color: #0f172a;
    border-bottom-color: #e2e8f0;
}

html[data-theme="light"] .edu-card h4,
html:not(.dark):not([data-theme="dark"]) .edu-card h4 {
    color: #0284c7;
}

html[data-theme="light"] .edu-card p,
html:not(.dark):not([data-theme="dark"]) .edu-card p,
html[data-theme="light"] .edu-card ul,
html:not(.dark):not([data-theme="dark"]) .edu-card ul {
    color: #334155;
}

html[data-theme="light"] .formula-box,
html:not(.dark):not([data-theme="dark"]) .formula-box {
    background: #f8fafc;
    border-color: #bae6fd;
    color: #0369a1;
}

html[data-theme="light"] .quote-box,
html:not(.dark):not([data-theme="dark"]) .quote-box {
    background: #faf5ff;
    border-left-color: #a855f7;
    color: #581c87;
}

html[data-theme="light"] .edu-table th,
html:not(.dark):not([data-theme="dark"]) .edu-table th {
    background: #f1f5f9;
    color: #0369a1;
    border-bottom-color: #e2e8f0;
}

html[data-theme="light"] .edu-table td,
html:not(.dark):not([data-theme="dark"]) .edu-table td {
    color: #334155;
    border-bottom-color: #e2e8f0;
}

html[data-theme="light"] .flow-step,
html:not(.dark):not([data-theme="dark"]) .flow-step {
    background: #f8fafc;
    border-color: #e2e8f0;
}

html[data-theme="light"] .step-num,
html:not(.dark):not([data-theme="dark"]) .step-num {
    background: #e0f2fe;
    color: #0284c7;
}

html[data-theme="light"] .step-desc,
html:not(.dark):not([data-theme="dark"]) .step-desc {
    color: #334155;
}

html[data-theme="light"] .quiz-question,
html:not(.dark):not([data-theme="dark"]) .quiz-question {
    color: #0f172a;
}

html[data-theme="light"] .quiz-opt-btn,
html:not(.dark):not([data-theme="dark"]) .quiz-opt-btn {
    background: #ffffff;
    border-color: #e2e8f0;
    color: #334155;
}

html[data-theme="light"] .quiz-opt-btn:hover,
html:not(.dark):not([data-theme="dark"]) .quiz-opt-btn:hover {
    border-color: #0284c7;
    background: #f0f9ff;
}

html[data-theme="light"] .calc-input,
html:not(.dark):not([data-theme="dark"]) .calc-input {
    background: #ffffff;
    border-color: #cbd5e1;
    color: #0f172a;
}

html[data-theme="light"] .calc-result,
html:not(.dark):not([data-theme="dark"]) .calc-result {
    background: #f0fdf4;
    border-color: #86efac;
    color: #15803d;
}

html[data-theme="light"] .app-footer,
html:not(.dark):not([data-theme="dark"]) .app-footer {
    border-top-color: #e2e8f0;
    color: #64748b;
}

html[data-theme="light"] .footer-note,
html:not(.dark):not([data-theme="dark"]) .footer-note {
    color: #94a3b8;
}