:root {
    /* --- USER Palette --- */
    --white: #FFFFFF;
    --black: #000000;
    --black-75: #404040;
    --black-50: #7F7F7F;
    --black-25: #BFBFBF;
    --green: #00AF89;
    --blue: #0063BF;
    --red: #990000;
    --green-aaa: #246342;
    --blue-aaa: #0C57A8;
    --red-aaa: #970302;
    --pink: #E679A6;
    --orange: #EE8019;
    --yellow: #F0BC00;
    --purple: #5748B5;
    --dark-green: #305D70;
    --bright-blue: #049DFF;
    --bright-yellow: #E9E7C4;
    --bright-green: #71D1B3;

    /* Light Variants */
    --red-light: #E5C0C0;
    --pink-light: #F9DDE9;
    --orange-light: #FBDFC5;
    --yellow-light: #FBEEBF;
    --purple-light: #D5D1EC;
    --dark-green-light: #CBD6DB;
    --blue-light: #C3D8EF;
    --bright-blue-light: #C0E6FF;
    --bright-yellow-light: #F9F9F0;
    --green-light: #CBE0D5;
    --bright-green-light: #DBF3EC;

    /* Semantic Mappings */
    --void: var(--black);
    --charcoal: var(--black-75);
    --ash: var(--black-50);
    --smoke: #1A1A1A;
    --cinder: #2D2D2D;
    --text-primary: var(--white);
    --text-secondary: var(--black-25);
    --text-dim: var(--black-50);
    --ember: var(--orange);
    --flame: var(--orange);
    --ignition: var(--yellow);
    --heat: var(--bright-yellow);
    --danger: var(--red);
    --success: var(--green);
    --brand: var(--blue);

    --font-display: 'Space Grotesk', sans-serif;
    --font-mono: 'JetBrains Mono', monospace;
    --phi: 1.61803398875;
    --phi-inv: 0.61803398875;

    --space-unit: 10px;
    --space-xs: calc(var(--space-unit) * var(--phi-inv) * var(--phi-inv));
    --space-sm: calc(var(--space-unit) * var(--phi-inv));
    --space-md: var(--space-unit);
    --space-lg: calc(var(--space-unit) * var(--phi));
    --space-xl: calc(var(--space-unit) * var(--phi) * var(--phi));
    --space-xxl: calc(var(--space-unit) * var(--phi) * var(--phi) * var(--phi));

    --transition-fast: 0.15s ease;
    --transition-normal: 0.3s ease;
}

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

html,
body {
    width: 100%;
    height: 100%;
    overflow: hidden;
    background: var(--void);
    color: var(--text-primary);
    font-family: var(--font-mono);
    font-size: 14px;
    -webkit-font-smoothing: antialiased;
}

#game-container {
    width: 100%;
    height: 100%;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
}

.screen {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.5s, visibility 0.5s;
}

.screen.active {
    opacity: 1;
    visibility: visible;
}

#title-screen {
    background: radial-gradient(ellipse at 50% 80%, rgba(255, 107, 53, 0.08) 0%, transparent 50%), var(--void);
}

.title-content {
    text-align: center;
    max-width: 600px;
    padding: var(--space-xl);
}

.title-content h1 {
    font-family: var(--font-display);
    font-size: clamp(2.5rem, calc(4vw * var(--phi)), 5rem);
    font-weight: 700;
    letter-spacing: -0.02em;
    margin-bottom: calc(var(--space-md) * var(--phi-inv));
    position: relative;
}

.glitch-text {
    animation: glitch-skew 4s infinite linear alternate-reverse;
}

.glitch-text::before,
.glitch-text::after {
    content: attr(data-text);
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

.glitch-text::before {
    color: var(--ember);
    animation: glitch-anim 3s infinite linear alternate-reverse;
    clip-path: polygon(0 0, 100% 0, 100% 35%, 0 35%);
}

.glitch-text::after {
    color: var(--ignition);
    animation: glitch-anim2 2s infinite linear alternate-reverse;
    clip-path: polygon(0 65%, 100% 65%, 100% 100%, 0 100%);
}

@keyframes glitch-skew {

    0%,
    100% {
        transform: skew(0deg);
    }

    50% {
        transform: skew(-0.5deg);
    }
}

@keyframes glitch-anim {

    0%,
    100% {
        transform: translate(0);
    }

    50% {
        transform: translate(-2px, 1px);
    }
}

@keyframes glitch-anim2 {

    0%,
    100% {
        transform: translate(0);
    }

    50% {
        transform: translate(2px, -1px);
    }
}

.subtitle {
    font-size: 1rem;
    font-weight: 300;
    color: var(--text-secondary);
    margin-bottom: var(--space-xl);
    letter-spacing: 0.05em;
}

.title-stats {
    display: flex;
    justify-content: center;
    gap: var(--space-xl);
    margin-bottom: var(--space-xl);
    flex-wrap: wrap;
}

.stat-block {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-xs);
}

.stat-label {
    font-size: 0.7rem;
    font-weight: 500;
    color: var(--text-dim);
    letter-spacing: 0.1em;
}

.stat-value {
    font-family: var(--font-display);
    font-size: 1.8rem;
    font-weight: 600;
}

.fuel-btn {
    font-family: var(--font-mono);
    font-size: 0.9rem;
    font-weight: 500;
    letter-spacing: 0.08em;
    padding: var(--space-md) calc(var(--space-md) * var(--phi));
    border: 1px solid var(--ember);
    background: transparent;
    color: var(--ember);
    cursor: pointer;
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
    display: block;
    margin: var(--space-md) auto;
    min-width: calc(140px * var(--phi));
}

.fuel-btn::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(90deg, var(--ember), var(--flame));
    opacity: 0;
    transition: opacity var(--transition-normal);
    z-index: -1;
}

.fuel-btn:hover {
    color: var(--void);
    border-color: var(--flame);
    box-shadow: 0 0 30px rgba(255, 107, 53, 0.3);
}

.fuel-btn:hover::before {
    opacity: 1;
}

.fuel-btn.secondary {
    border-color: var(--black-50);
    color: var(--black-25);
}

.fuel-btn.secondary::before {
    background: var(--black-75);
}

.fuel-btn.secondary:hover {
    color: var(--white);
    border-color: var(--white);
    box-shadow: 0 0 20px rgba(255, 255, 255, 0.1);
}

.fuel-btn.accent {
    border-color: var(--blue);
    color: var(--blue-light);
}

.fuel-btn.accent::before {
    background: linear-gradient(90deg, var(--blue), var(--bright-blue));
}

.fuel-btn.accent:hover {
    color: var(--white);
    border-color: var(--bright-blue);
    box-shadow: 0 0 30px rgba(4, 157, 255, 0.3);
}

.fuel-btn.danger {
    border-color: var(--red);
    color: var(--red-light);
}

.fuel-btn.danger::before {
    background: linear-gradient(90deg, var(--red), var(--red-aaa));
}

.fuel-btn.danger:hover {
    color: var(--white);
    border-color: var(--red-aaa);
    box-shadow: 0 0 30px rgba(153, 0, 0, 0.3);
}

#game-canvas {
    display: block;
    background: var(--charcoal);
}

#hud {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    display: flex;
    justify-content: space-between;
    padding: var(--space-md) calc(var(--space-md) * var(--phi));
    pointer-events: none;
    z-index: 10;
}

.hud-left,
.hud-right {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.hud-right {
    align-items: flex-end;
}

.hud-center {
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    top: var(--space-md);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
}


.hud-stat {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.hud-label {
    font-size: 0.65rem;
    font-weight: 500;
    color: var(--text-dim);
    letter-spacing: 0.15em;
}

.hud-value {
    font-family: var(--font-display);
    font-size: 1.4rem;
    font-weight: 600;
}

.hud-value.ignition {
    color: var(--ignition);
    text-shadow: 0 0 20px rgba(255, 166, 43, 0.5);
}

.engine-status {
    background: var(--smoke);
    border: 1px solid var(--charcoal);
    padding: var(--space-xs) var(--space-md);
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.1em;
    color: var(--bright-green-light);
    border-radius: 4px;
}

.overlay {
    position: absolute;
    inset: 0;
    background: rgba(10, 10, 11, 0.95);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 100;
    transition: opacity var(--transition-normal);
}

.overlay.hidden {
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
}

.death-content,
.pause-content {
    text-align: center;
    max-width: 500px;
    padding: var(--space-xl);
    animation: death-enter 0.5s ease-out;
}

@keyframes death-enter {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.death-title {
    font-family: var(--font-display);
    font-size: 3rem;
    font-weight: 700;
    color: var(--red);
    text-shadow: 0 0 20px rgba(153, 0, 0, 0.4);
    margin-bottom: var(--space-sm);
    letter-spacing: -0.05em;
}

.death-cause {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: var(--space-xl);
}

.death-stats {
    display: flex;
    justify-content: center;
    gap: var(--space-xl);
    margin-bottom: var(--space-lg);
}

.death-stat {
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
}

.death-label {
    font-size: 0.7rem;
    color: var(--text-dim);
    letter-spacing: 0.1em;
}

.death-value {
    font-family: var(--font-display);
    font-size: 1.6rem;
    font-weight: 600;
}

.death-value.ignition {
    color: var(--ignition);
    animation: ignition-glow 1.5s ease-in-out infinite;
}

@keyframes ignition-glow {

    0%,
    100% {
        text-shadow: 0 0 10px rgba(255, 166, 43, 0.5);
    }

    50% {
        text-shadow: 0 0 25px rgba(255, 166, 43, 0.8);
    }
}

.refinement-preview {
    background: var(--smoke);
    border: 1px solid var(--charcoal);
    padding: var(--space-md);
    margin-bottom: var(--space-lg);
    text-align: left;
}

.refinement-item {
    display: flex;
    justify-content: space-between;
    padding: var(--space-xs) 0;
    border-bottom: 1px solid var(--smoke);
}

.refinement-item:last-child {
    border-bottom: none;
}

.refinement-name {
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.refinement-change {
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--success);
}

/* Investment Screen */
.investment-screen {
    max-width: 700px;
    width: 90vw;
}

.death-header {
    margin-bottom: var(--space-lg);
}

.investment-section {
    background: var(--smoke);
    border: 1px solid var(--charcoal);
    padding: var(--space-lg);
    margin-bottom: var(--space-lg);
    text-align: left;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
}

.investment-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--space-lg);
    padding-bottom: var(--space-sm);
    border-bottom: 1px solid var(--smoke);
}

.investment-header h3 {
    font-family: var(--font-display);
    font-size: 1rem;
    font-weight: 600;
    letter-spacing: 0.1em;
    color: var(--text-primary);
}

.ignition-pool {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.pool-label {
    font-size: 0.7rem;
    color: var(--text-dim);
    letter-spacing: 0.1em;
}

.pool-value {
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--ignition);
    text-shadow: 0 0 15px rgba(255, 166, 43, 0.5);
}

.upgrade-categories {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-md);
}

.upgrade-category.sensors h4 {
    border-color: var(--blue);
    color: var(--bright-blue);
}

.upgrade-category.logic h4 {
    border-color: var(--pink);
    color: var(--pink);
}

.upgrade-category.motors h4 {
    border-color: var(--orange);
    color: var(--orange);
}

.upgrade-category.database h4 {
    border-color: var(--green);
    color: var(--green);
}

.upgrade-category h4 {
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.15em;
    margin-bottom: var(--space-sm);
    padding-bottom: var(--space-xs);
    border-bottom: 2px solid var(--smoke);
}

.upgrade-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
}

.upgrade-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--space-sm);
    background: var(--void);
    border: 1px solid var(--smoke);
    border-left: 3px solid var(--ash);
    transition: all var(--transition-fast);
}

.sensors .upgrade-row {
    border-left-color: var(--blue);
}

.logic .upgrade-row {
    border-left-color: var(--pink);
}

.motors .upgrade-row {
    border-left-color: var(--orange);
}

.database .upgrade-row {
    border-left-color: var(--green);
}

.upgrade-row:hover {
    border-color: var(--ash);
    transform: translateX(4px);
}

.upgrade-info {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.upgrade-name {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--white);
    letter-spacing: 0.02em;
}

.sensors .upgrade-name {
    color: var(--bright-blue-light);
}

.logic .upgrade-name {
    color: var(--pink-light);
}

.motors .upgrade-name {
    color: var(--orange-light);
}

.database .upgrade-name {
    color: var(--green-light);
}

.upgrade-value {
    font-size: 0.7rem;
    color: var(--black-25);
    font-family: var(--font-mono);
}

.upgrade-controls {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    background: var(--smoke);
    padding: 3px;
    border-radius: 4px;
    border: 1px solid var(--cinder);
}

.control-btn {
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px solid var(--charcoal);
    background: var(--black-75);
    color: var(--white);
    cursor: pointer;
    font-size: 1.1rem;
    font-weight: bold;
    transition: all var(--transition-fast);
}

.sensors .control-btn:hover:not(:disabled) {
    border-color: var(--bright-blue);
    color: var(--bright-blue);
    box-shadow: 0 0 10px var(--blue);
}

.logic .control-btn:hover:not(:disabled) {
    border-color: var(--pink);
    color: var(--pink);
    box-shadow: 0 0 10px var(--purple);
}

.motors .control-btn:hover:not(:disabled) {
    border-color: var(--orange);
    color: var(--orange);
    box-shadow: 0 0 10px var(--red);
}

.database .control-btn:hover:not(:disabled) {
    border-color: var(--green);
    color: var(--green);
    box-shadow: 0 0 10px var(--green-aaa);
}

.control-btn:disabled {
    opacity: 0.2;
    cursor: not-allowed;
    filter: grayscale(1);
}

.upgrade-level {
    font-family: var(--font-display);
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--ignition);
    min-width: 30px;
    text-align: center;
}

.upgrade-cost {
    font-size: 0.7rem;
    font-weight: 600;
    color: var(--ignition);
}

.prediction-result {
    margin-top: 20px;
    text-align: center;
    font-family: var(--font-mono);
    font-size: 0.8rem;
    padding: 10px;
    background: var(--smoke);
    border: 1px solid var(--cinder);
}

.next-run-forecast {
    text-align: center;
    margin-bottom: 20px;
    color: var(--text-dim);
    font-size: 0.9rem;
    font-family: var(--font-mono);
}

.upgrade-bar {
    width: 100%;
    height: 3px;
    background: var(--smoke);
    margin-top: var(--space-xs);
    position: relative;
}

.upgrade-bar-fill {
    position: absolute;
    left: 0;
    top: 0;
    height: 100%;
    background: linear-gradient(90deg, var(--ember), var(--ignition));
    transition: width var(--transition-normal);
}

.death-actions {
    display: flex;
    gap: var(--space-md);
    justify-content: center;
}

.death-actions .fuel-btn {
    margin: 0;
}

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

    .death-actions {
        flex-direction: column;
    }
}

.pause-content h2 {
    font-family: var(--font-display);
    font-size: 2rem;
    margin-bottom: var(--space-lg);
}

.panel {
    position: absolute;
    right: 0;
    top: 0;
    bottom: 0;
    width: 320px;
    background: var(--charcoal);
    border-left: 1px solid var(--smoke);
    z-index: 50;
    display: flex;
    flex-direction: column;
    transition: transform var(--transition-normal);
}

.panel.hidden {
    transform: translateX(100%);
    pointer-events: none;
}

.panel-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--space-md) var(--space-lg);
    border-bottom: 1px solid var(--smoke);
}

.panel-header h3 {
    font-family: var(--font-display);
    font-size: 0.9rem;
    font-weight: 600;
    letter-spacing: 0.1em;
    color: var(--ember);
}

.panel-close {
    background: none;
    border: none;
    color: var(--text-dim);
    font-size: 1.5rem;
    cursor: pointer;
}

.panel-close:hover {
    color: var(--text-primary);
}

.panel-content {
    flex: 1;
    overflow-y: auto;
    padding: var(--space-md);
}

.engine-section {
    margin-bottom: var(--space-lg);
}

.engine-section h4 {
    font-size: 0.7rem;
    font-weight: 600;
    color: var(--text-dim);
    letter-spacing: 0.15em;
    margin-bottom: var(--space-sm);
    border-bottom: 1px solid var(--smoke);
    padding-bottom: var(--space-xs);
}

.var-group {
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
}

.var-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--space-xs) var(--space-sm);
    background: var(--ash);
}

.var-name {
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.var-value {
    font-size: 0.75rem;
    font-weight: 500;
}

.var-bar {
    width: 60px;
    height: 4px;
    background: var(--smoke);
    margin-left: var(--space-sm);
    position: relative;
}

.var-bar-fill {
    position: absolute;
    left: 0;
    top: 0;
    height: 100%;
    background: linear-gradient(90deg, var(--ember), var(--ignition));
    transition: width var(--transition-normal);
}

.engine-toggle {
    position: absolute;
    right: var(--space-md);
    bottom: var(--space-md);
    width: 48px;
    height: 48px;
    background: var(--ash);
    border: 1px solid var(--smoke);
    color: var(--text-secondary);
    font-size: 1.5rem;
    cursor: pointer;
    z-index: 40;
    display: flex;
    align-items: center;
    justify-content: center;
}

.engine-toggle:hover {
    background: var(--smoke);
    color: var(--ember);
    border-color: var(--ember);
}

@media (max-width: 768px) {
    .title-stats {
        flex-direction: column;
        gap: var(--space-md);
    }

    .panel {
        width: 100%;
    }
}

/* --- TOOLTIPS --- */
.upgrade-row {
    position: relative;
}

.upgrade-row[data-tooltip]::after {
    content: attr(data-tooltip);
    position: absolute;
    bottom: calc(100% + 10px);
    left: 50%;
    transform: translateX(-50%) translateY(10px);
    width: 240px;
    padding: var(--space-sm) var(--space-md);
    background: var(--charcoal);
    border: 1px solid var(--ember);
    color: var(--text-primary);
    font-size: 0.75rem;
    line-height: 1.4;
    text-align: center;
    pointer-events: none;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
    z-index: 1000;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.8), inset 0 0 10px rgba(255, 107, 53, 0.1);
    font-family: var(--font-mono);
}

.upgrade-row[data-tooltip]::before {
    content: '';
    position: absolute;
    bottom: 100%;
    left: 50%;
    transform: translateX(-50%) translateY(10px);
    border-width: 5px;
    border-style: solid;
    border-color: var(--ember) transparent transparent transparent;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
    z-index: 1000;
}

.upgrade-row[data-tooltip]:hover::after,
.upgrade-row[data-tooltip]:hover::before {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0);
    transition-delay: 0.5s;
}

.upgrade-list,
.upgrade-category,
.upgrade-categories {
    overflow: visible;
}