:root {
    --bg-dark: #06060c;
    --cyan-neon: #00f3ff;
    --pink-neon: #ff007b;
    --cyan-glow: rgba(0, 243, 255, 0.4);
    --pink-glow: rgba(255, 0, 123, 0.4);
    --white: #ffffff;
    --gray: #8892b0;
    --dark-blue: #0b0f19;
    --glass-bg: rgba(6, 8, 20, 0.75);
    --glass-border: rgba(255, 255, 255, 0.07);
    --glass-shadow: 0 24px 64px rgba(0, 0, 0, 0.8), inset 0 1px 0 rgba(255, 255, 255, 0.1);
    --red-neon: #ff2d55;
    --red-glow: rgba(255, 45, 85, 0.4);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    user-select: none;
    -webkit-user-select: none;
    touch-action: none; /* Prevents double-tap zoom on mobile */
}

body {
    background-color: var(--bg-dark);
    color: var(--white);
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    overflow: hidden;
    width: 100vw;
    height: 100vh;
}

/* Game Container holds canvas and overlay screens */
#game-container {
    position: relative;
    width: 100%;
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;
}

canvas {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: block;
    z-index: 1;
}

/* UI Overlay Screens */
.screen-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 10;
    background: rgba(4, 4, 8, 0.6);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    transition: opacity 0.4s cubic-bezier(0.16, 1, 0.3, 1), visibility 0.4s;
    opacity: 1;
    visibility: visible;
}

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

/* Glassmorphic Panel UI */
.glass-panel {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 24px;
    box-shadow: var(--glass-shadow);
    padding: 3rem 2.5rem;
    max-width: 580px;
    width: 90%;
    text-align: center;
    transform: translateY(0);
    transition: transform 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
}

.screen-overlay.hidden .glass-panel {
    transform: translateY(30px);
}

/* Logo & Game Title */
.logo-area {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    margin-bottom: 1rem;
}

.logo-magnet {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: 'Orbitron', sans-serif;
    font-size: 2rem;
    font-weight: 900;
    box-shadow: 0 0 15px currentColor;
}

.logo-magnet.positive-pulse {
    background: var(--cyan-neon);
    color: var(--bg-dark);
    box-shadow: 0 0 20px var(--cyan-glow);
    animation: pulseCyan 2s infinite ease-in-out;
}

.logo-magnet.negative-pulse {
    background: var(--pink-neon);
    color: var(--white);
    box-shadow: 0 0 20px var(--pink-glow);
    animation: pulsePink 2s infinite ease-in-out;
}

@keyframes pulseCyan {
    0%, 100% { transform: scale(1); box-shadow: 0 0 15px var(--cyan-glow); }
    50% { transform: scale(1.1); box-shadow: 0 0 30px var(--cyan-neon); }
}

@keyframes pulsePink {
    0%, 100% { transform: scale(1); box-shadow: 0 0 15px var(--pink-glow); }
    50% { transform: scale(1.1); box-shadow: 0 0 30px var(--pink-neon); }
}

.game-title {
    font-family: 'Orbitron', sans-serif;
    font-size: 2.75rem;
    font-weight: 900;
    letter-spacing: 2px;
    margin-bottom: 0.25rem;
    text-transform: uppercase;
}

.cyan-text {
    color: var(--cyan-neon);
    text-shadow: 0 0 10px var(--cyan-glow);
}

.subtitle {
    font-family: 'Orbitron', sans-serif;
    font-size: 0.85rem;
    font-weight: 700;
    letter-spacing: 6px;
    color: var(--gray);
    margin-bottom: 2rem;
}

/* Instructions Layout */
.instructions {
    margin-bottom: 2rem;
    text-align: left;
}

.instruction-row {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    background: rgba(255, 255, 255, 0.03);
    padding: 0.75rem 1rem;
    border-radius: 12px;
    border: 1px solid rgba(255, 255, 255, 0.05);
    margin-bottom: 1rem;
}

.instruction-row p {
    font-size: 0.85rem;
    color: var(--white);
    line-height: 1.4;
}

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

.instruction-box {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid rgba(255, 255, 255, 0.04);
    border-radius: 16px;
    padding: 1.25rem 1rem;
    transition: transform 0.3s ease, border-color 0.3s ease;
}

.instruction-box:hover {
    transform: translateY(-2px);
    background: rgba(255, 255, 255, 0.04);
    border-color: rgba(255, 255, 255, 0.08);
}

.box-icon {
    font-size: 1.75rem;
    margin-bottom: 0.5rem;
}

.attract-icon {
    color: var(--cyan-neon);
    text-shadow: 0 0 10px var(--cyan-glow);
}

.repel-icon {
    color: var(--pink-neon);
    text-shadow: 0 0 10px var(--pink-glow);
}

.instruction-box h3 {
    font-family: 'Orbitron', sans-serif;
    font-size: 0.9rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.instruction-box p {
    font-size: 0.75rem;
    color: var(--gray);
    line-height: 1.4;
}

.controls-guide {
    background: rgba(255, 255, 255, 0.01);
    border-top: 1px solid rgba(255, 255, 255, 0.05);
    padding-top: 1rem;
    margin-bottom: 2rem;
}

.controls-guide p {
    font-size: 0.8rem;
    color: var(--gray);
    line-height: 1.5;
    margin-bottom: 0.25rem;
}

.controls-guide strong {
    color: var(--white);
}

/* Glowing Neon Buttons */
.action-btn {
    width: 100%;
    padding: 1rem 2rem;
    font-family: 'Orbitron', sans-serif;
    font-size: 1.1rem;
    font-weight: 800;
    letter-spacing: 2px;
    border-radius: 12px;
    border: none;
    cursor: pointer;
    background: transparent;
    transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
    position: relative;
    overflow: hidden;
}

.glow-btn {
    border: 2px solid var(--cyan-neon);
    color: var(--cyan-neon);
    box-shadow: 0 0 10px rgba(0, 243, 255, 0.1), inset 0 0 10px rgba(0, 243, 255, 0.05);
}

.glow-btn:hover {
    background: var(--cyan-neon);
    color: var(--bg-dark);
    box-shadow: 0 0 30px var(--cyan-neon);
    transform: scale(1.02);
}

.glow-btn:active {
    transform: scale(0.98);
}

/* UI HUD Overlay styling */
.hud-ui {
    position: absolute;
    top: 2rem;
    left: 2rem;
    right: 2rem;
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    z-index: 5;
    pointer-events: none; /* Let clicks pass through to canvas */
    transition: opacity 0.5s ease;
}

.hud-ui.hidden {
    opacity: 0;
}

.hud-left, .hud-right {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    background: rgba(10, 12, 26, 0.5);
    border: 1px solid rgba(255, 255, 255, 0.05);
    padding: 0.75rem 1.25rem;
    border-radius: 16px;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

.hud-center {
    display: flex;
    justify-content: center;
}

.hud-stat-container {
    display: flex;
    flex-direction: column;
}

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

.label {
    font-size: 0.65rem;
    letter-spacing: 2px;
    color: var(--gray);
    font-family: 'Orbitron', sans-serif;
    font-weight: 700;
    margin-bottom: 0.15rem;
}

.value {
    font-family: 'Orbitron', sans-serif;
    font-size: 1.5rem;
    font-weight: 900;
    color: var(--white);
    letter-spacing: 1px;
}

/* Polarity Badges */
.badge {
    padding: 0.6rem 1.2rem;
    border-radius: 12px;
    font-family: 'Orbitron', sans-serif;
    font-weight: 900;
    font-size: 0.85rem;
    letter-spacing: 2px;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
    border: 1px solid rgba(255, 255, 255, 0.1);
    transition: all 0.25s ease;
}

.badge.inline {
    display: inline-flex;
    justify-content: center;
    width: 28px;
    height: 28px;
    padding: 0;
    border-radius: 6px;
    font-size: 0.95rem;
    flex-shrink: 0;
}

.badge.positive {
    background: var(--cyan-neon);
    color: var(--bg-dark);
    box-shadow: 0 0 20px var(--cyan-glow);
}

.badge.negative {
    background: var(--pink-neon);
    color: var(--white);
    box-shadow: 0 0 20px var(--pink-glow);
}

#polarity-badge {
    animation: badgeFloat 2s infinite ease-in-out;
}

@keyframes badgeFloat {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-4px); }
}

/* Health/Shield Bar */
.health-bar-container {
    width: 120px;
    height: 8px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 4px;
    overflow: hidden;
    margin-top: 0.25rem;
    box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.5);
}

.health-fill {
    height: 100%;
    width: 100%;
    background: linear-gradient(90deg, var(--pink-neon), var(--cyan-neon));
    box-shadow: 0 0 8px var(--cyan-glow);
    border-radius: 4px;
    transition: width 0.3s cubic-bezier(0.16, 1, 0.3, 1), background 0.3s ease;
}

/* Game Over Styles */
.game-over-panel {
    border-color: rgba(255, 45, 85, 0.25);
    box-shadow: 0 24px 64px rgba(255, 45, 85, 0.1), 0 24px 64px rgba(0, 0, 0, 0.7);
}

.danger-icon {
    font-size: 3rem;
    color: var(--red-neon);
    animation: alarmPulse 1.5s infinite;
    margin-bottom: 0.5rem;
}

@keyframes alarmPulse {
    0%, 100% { transform: scale(1); opacity: 0.8; }
    50% { transform: scale(1.15); opacity: 1; filter: drop-shadow(0 0 15px var(--red-neon)); }
}

.game-over-title {
    font-family: 'Orbitron', sans-serif;
    font-size: 2.5rem;
    font-weight: 900;
    letter-spacing: 2px;
    text-transform: uppercase;
}

.glow-text-red {
    color: var(--red-neon);
    text-shadow: 0 0 15px var(--red-glow);
}

.game-over-subtitle {
    font-family: 'Orbitron', sans-serif;
    font-size: 0.8rem;
    font-weight: 700;
    letter-spacing: 4px;
    color: var(--gray);
    margin-bottom: 2rem;
}

.score-summary {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.05);
    padding: 1.25rem;
    border-radius: 16px;
    margin-bottom: 2rem;
}

.score-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.glow-btn-red {
    border: 2px solid var(--red-neon);
    color: var(--red-neon);
    box-shadow: 0 0 10px rgba(255, 45, 85, 0.1);
}

.glow-btn-red:hover {
    background: var(--red-neon);
    color: var(--white);
    box-shadow: 0 0 30px var(--red-neon);
    transform: scale(1.02);
}

.restart-hint {
    font-size: 0.75rem;
    color: var(--gray);
    margin-top: 1rem;
    animation: blinkHint 1.8s infinite;
}

@keyframes blinkHint {
    0%, 100% { opacity: 0.4; }
    50% { opacity: 0.9; }
}

/* Glow utility classes */
.glow-text {
    text-shadow: 0 0 10px var(--cyan-glow), 0 0 20px var(--pink-glow);
}

.glow-text-cyan {
    color: var(--cyan-neon);
    text-shadow: 0 0 10px var(--cyan-glow);
}

/* --- Responsive Media Queries --- */
@media (max-width: 600px) {
    .glass-panel {
        padding: 2rem 1.5rem;
        border-radius: 20px;
    }

    .game-title {
        font-size: 2rem;
    }

    .subtitle {
        font-size: 0.75rem;
        letter-spacing: 4px;
        margin-bottom: 1.5rem;
    }

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

    .instruction-box {
        padding: 1rem;
        display: flex;
        align-items: center;
        gap: 1rem;
        text-align: left;
    }

    .instruction-box h3 {
        margin-bottom: 0.2rem;
    }

    .box-icon {
        font-size: 1.5rem;
        margin-bottom: 0;
        flex-shrink: 0;
    }

    .instruction-box div {
        flex-grow: 1;
    }

    .controls-guide p {
        font-size: 0.75rem;
    }

    .hud-ui {
        top: 1rem;
        left: 1rem;
        right: 1rem;
        gap: 0.5rem;
    }

    .hud-left, .hud-right {
        padding: 0.5rem 0.75rem;
        border-radius: 12px;
    }

    .value {
        font-size: 1.1rem;
    }

    .badge {
        padding: 0.4rem 0.8rem;
        font-size: 0.75rem;
    }

    .health-bar-container {
        width: 80px;
    }

    .game-over-title {
        font-size: 1.8rem;
    }
}

@media (max-height: 700px) and (min-width: 600px) {
    .glass-panel {
        padding: 1.5rem 2rem;
    }

    .logo-area {
        margin-bottom: 0.5rem;
    }

    .game-title {
        font-size: 2.2rem;
        margin-bottom: 0;
    }

    .subtitle {
        margin-bottom: 1rem;
    }

    .instructions {
        margin-bottom: 1rem;
    }

    .controls-guide {
        margin-bottom: 1rem;
        padding-top: 0.5rem;
    }
}