:root {
    /* Color Palette */
    --bg-gradient-start: #0f172a;
    --bg-gradient-end: #1e1b4b;
    --glass-bg: rgba(255, 255, 255, 0.07);
    --glass-border: rgba(255, 255, 255, 0.12);
    --glass-glow: rgba(255, 255, 255, 0.03);
    --text-primary: #f8fafc;
    --text-secondary: #cbd5e1;
    
    /* System Specific Accents */
    --accent-primary: #6366f1;
    --accent-primary-hover: #4f46e5;
    --accent-secondary: rgba(255, 255, 255, 0.15);
    --accent-secondary-hover: rgba(255, 255, 255, 0.25);
    
    /* Channels */
    --red-channel: #ef4444;
    --green-channel: #22c55e;
    --blue-channel: #3b82f6;
    
    /* Layout constants */
    --border-radius-lg: 24px;
    --border-radius-md: 16px;
    --border-radius-sm: 8px;
    --font-stack: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    --transition-speed: 0.3s;
}

/* Light Mode Variations overrides */
[data-theme="light"] {
    --bg-gradient-start: #f1f5f9;
    --bg-gradient-end: #e2e8f0;
    --glass-bg: rgba(0, 0, 0, 0.04);
    --glass-border: rgba(0, 0, 0, 0.1);
    --glass-glow: rgba(0, 0, 0, 0.01);
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --accent-secondary: rgba(0, 0, 0, 0.05);
    --accent-secondary-hover: rgba(0, 0, 0, 0.12);
}

/* Reset baseline specifications */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    user-select: none;
    -webkit-user-select: none;
    touch-action: manipulation; /* Prevents double-tap zooming issues on mobile inputs */
}

body {
    font-family: var(--font-stack);
    background: linear-gradient(135deg, var(--bg-gradient-start), var(--bg-gradient-end));
    color: var(--text-primary);
    min-height: 100vh;
    min-height: -webkit-fill-available; /* Fixed viewport metrics height on mobile safari browser handles */
    display: flex;
    align-items: center;
    justify-content: center;
    overflow-x: hidden;
    overflow-y: auto;
    padding: 16px;
    position: relative;
}

html {
    height: -webkit-fill-available;
}

/* Active background animation environments */
#particleCanvas, #confettiCanvas {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
    pointer-events: none;
}

#confettiCanvas {
    z-index: 999;
}

/* Fluid Organic Background Blobs */
.blob {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    z-index: 2;
    opacity: 0.45;
    mix-blend-mode: screen;
    animation: floatingBlob 18s infinite alternate ease-in-out;
}
[data-theme="light"] .blob {
    mix-blend-mode: multiply;
    opacity: 0.15;
}
.blob-1 { width: 300px; height: 300px; background: var(--red-channel); top: -50px; left: -50px; }
.blob-2 { width: 350px; height: 350px; background: var(--blue-channel); bottom: -100px; right: -50px; animation-delay: -4s; }
.blob-3 { width: 250px; height: 250px; background: var(--green-channel); top: 40%; left: 50%; animation-delay: -8s; }

@keyframes floatingBlob {
    0% { transform: translate(0, 0) scale(1); }
    50% { transform: translate(30px, -50px) scale(1.1); }
    100% { transform: translate(-20px, 20px) scale(0.9); }
}

/* Glassmorphism Structural Panel Wrapper */
.glass-panel {
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border);
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.15), inset 0 1px 0 var(--glass-glow);
    border-radius: var(--border-radius-lg);
    width: 100%;
    max-width: 520px;
    padding: 24px;
    z-index: 3;
    position: relative;
    transition: transform var(--transition-speed) cubic-bezier(0.34, 1.56, 0.64, 1), box-shadow var(--transition-speed);
}
.glass-panel-nested {
    background: rgba(0, 0, 0, 0.12);
    border: 1px solid var(--glass-border);
    border-radius: var(--border-radius-md);
    padding: 18px;
}
[data-theme="light"] .glass-panel-nested {
    background: rgba(255, 255, 255, 0.4);
}

/* Utilities System Layout Elements */
#utilityBar {
    display: flex;
    justify-content: flex-end;
    gap: 10px;
    margin-bottom: 12px;
}
.icon-btn {
    background: var(--accent-secondary);
    border: 1px solid var(--glass-border);
    color: var(--text-primary);
    width: 38px;
    height: 38px;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.05rem;
    transition: transform 0.2s, background-color 0.2s;
}
.icon-btn:hover { transform: scale(1.1); background: var(--accent-secondary-hover); }
.icon-btn:active { transform: scale(0.95); }

/* Screen Switch Architecture */
.screen {
    display: none;
    opacity: 0;
    transform: translateY(12px);
    transition: opacity var(--transition-speed) ease, transform var(--transition-speed) ease;
}
.screen.active {
    display: block;
    opacity: 1;
    transform: translateY(0);
}

/* Typography elements definitions */
.game-title {
    font-size: 2.7rem;
    font-weight: 800;
    text-align: center;
    margin-bottom: 6px;
    letter-spacing: -1px;
    background: linear-gradient(to right, var(--red-channel), var(--green-channel), var(--blue-channel));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}
.game-subtitle {
    font-size: 0.98rem;
    color: var(--text-secondary);
    text-align: center;
    margin-bottom: 24px;
}
.special-text {
    background: linear-gradient(45deg, #f43f5e, #ec4899);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* Button UI Components */
.main-btn {
    font-family: var(--font-stack);
    font-weight: 600;
    font-size: 1rem;
    padding: 12px 24px;
    border-radius: var(--border-radius-md);
    border: none;
    cursor: pointer;
    transition: all 0.2s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}
.main-btn.primary {
    background: var(--accent-primary);
    color: white;
}
.main-btn.primary:hover {
    background: var(--accent-primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 6px 18px rgba(99, 102, 241, 0.35);
}
.main-btn.secondary {
    background: var(--accent-secondary);
    color: var(--text-primary);
    border: 1px solid var(--glass-border);
}
.main-btn.secondary:hover { transform: translateY(-2px); background: var(--accent-secondary-hover); }
.main-btn:active { transform: translateY(1px); }

/* Shared Helpers Grid Layout configurations */
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
.vertical-stack { display: flex; flex-direction: column; gap: 10px; }
.hidden { display: none !important; }

/* Dashboard Design Elements */
.menu-card {
    background: rgba(0, 0, 0, 0.15);
    border-radius: var(--border-radius-md);
    padding: 20px;
    margin-bottom: 20px;
    border: 1px solid var(--glass-border);
}
.menu-card h3 {
    font-size: 0.95rem;
    margin-bottom: 12px;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 1px;
}
.difficulty-selector { display: flex; flex-direction: column; gap: 8px; margin-bottom: 20px; }
.diff-btn {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--glass-border);
    border-radius: var(--border-radius-md);
    padding: 10px 16px;
    text-align: left;
    color: var(--text-primary);
    cursor: pointer;
    transition: all 0.15s ease;
    display: flex;
    flex-direction: column;
}
.diff-btn .diff-title { font-weight: 700; font-size: 1rem; }
.diff-btn .diff-desc { font-size: 0.8rem; color: var(--text-secondary); }
.diff-btn:hover { background: rgba(255, 255, 255, 0.07); }
.diff-btn.active {
    background: rgba(99, 102, 241, 0.15);
    border-color: var(--accent-primary);
}
.mode-selector { display: flex; gap: 12px; }
.mode-selector .main-btn { flex: 1; }

.stats-dashboard { margin-top: 8px; }
.stat-box {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: var(--border-radius-md);
    padding: 10px;
    text-align: center;
}
.stat-label { font-size: 0.7rem; text-transform: uppercase; color: var(--text-secondary); display: block; margin-bottom: 2px; }
.stat-value { font-size: 1.2rem; font-weight: 700; }

/* Gameplay UI Component Elements Layout */
.hud-bar {
    display: flex;
    justify-content: space-between;
    background: rgba(0, 0, 0, 0.12);
    border-radius: var(--border-radius-md);
    padding: 10px;
    margin-bottom: 20px;
    border: 1px solid var(--glass-border);
    gap: 4px;
}
.hud-item { text-align: center; flex: 1; }
.hud-label { font-size: 0.65rem; color: var(--text-secondary); display: block; font-weight: 600; }
.hud-value { font-size: 1.1rem; font-weight: 700; display: block; margin-top: 1px; }
.lives-row { display: flex; justify-content: center; gap: 2px; margin-top: 2px; }
.heart { font-size: 0.85rem; opacity: 0.2; transition: opacity 0.2s, transform 0.2s; }
.heart.active { opacity: 1; animation: heartBeat 1.2s infinite alternate; }

@keyframes heartBeat { 0% { transform: scale(1); } 100% { transform: scale(1.1); } }

#timerDisplay.warning-trigger { color: #ef4444; animation: urgentPulse 0.5s infinite alternate; }
@keyframes urgentPulse { 0% { transform: scale(1); } 100% { transform: scale(1.12); } }

/* Color Display Previews Cards block styling */
.color-preview-container { margin-bottom: 16px; }
.color-card {
    text-align: center;
    background: rgba(0,0,0,0.05);
    border-radius: var(--border-radius-md);
    padding: 10px;
    border: 1px solid var(--glass-border);
}
.color-card h4 { font-size: 0.8rem; margin-bottom: 6px; color: var(--text-secondary); text-transform: uppercase; }
.color-box {
    width: 100%;
    height: 120px;
    border-radius: var(--border-radius-md);
    box-shadow: inset 0 0 15px rgba(0,0,0,0.2), 0 6px 12px rgba(0,0,0,0.1);
    transition: background-color 0.1s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    color: white;
    text-shadow: 0 2px 4px rgba(0,0,0,0.5);
    font-size: 1.1rem;
    position: relative;
}

/* Hint Ticker element style */
.hint-ticker {
    text-align: center;
    font-size: 0.88rem;
    color: var(--text-secondary);
    min-height: 22px;
    margin-bottom: 16px;
    font-style: italic;
}

/* Configured Range Sliders Component Elements */
.sliders-control-group {
    background: rgba(0, 0, 0, 0.1);
    border-radius: var(--border-radius-md);
    padding: 16px;
    margin-bottom: 20px;
    border: 1px solid var(--glass-border);
    display: flex;
    flex-direction: column;
    gap: 12px;
}
.slider-row { display: flex; flex-direction: column; gap: 4px; }
.slider-meta { display: flex; justify-content: space-between; font-weight: 600; font-size: 0.9rem; }
.channel-value { font-family: monospace; font-size: 0.95rem; background: rgba(0,0,0,0.2); padding: 1px 6px; border-radius: 4px; }

/* Generic Input Slider Thumb Elements */
input[type="range"] {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    height: 12px;
    border-radius: 6px;
    background: rgba(255, 255, 255, 0.1);
    outline: none;
}
.red-channel input[type="range"] { background: linear-gradient(to right, #100, var(--red-channel)); }
.green-channel input[type="range"] { background: linear-gradient(to right, #010, var(--green-channel)); }
.blue-channel input[type="range"] { background: linear-gradient(to right, #001, var(--blue-channel)); }

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 26px;
    height: 26px;
    border-radius: 50%;
    background: #fff;
    cursor: pointer;
    box-shadow: 0 2px 6px rgba(0,0,0,0.4);
}
input[type="range"]::-moz-range-thumb {
    width: 26px;
    height: 26px;
    border: none;
    border-radius: 50%;
    background: #fff;
    cursor: pointer;
    box-shadow: 0 2px 6px rgba(0,0,0,0.4);
}

.action-row { display: flex; gap: 12px; }
.action-row button { flex: 1; }

/* Overlays Modal Structure Designs */
.overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(15, 23, 42, 0.65);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 100;
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition-speed) ease;
    padding: 16px;
}
.overlay:not(.hidden) { opacity: 1; pointer-events: auto; }
.overlay-card { width: 100%; max-width: 400px; text-align: center; padding: 24px; box-shadow: 0 30px 60px rgba(0,0,0,0.4); }
.overlay-card h2 { font-size: 1.8rem; margin-bottom: 8px; font-weight: 800; }
.stars-display { font-size: 2rem; margin: 10px 0; }
.accuracy-badge { font-size: 1.1rem; font-weight: 500; margin-bottom: 6px; color: var(--text-secondary); }
.accuracy-badge span { font-weight: 800; color: var(--text-primary); font-size: 1.4rem; }
#feedbackPointsAwarded { font-size: 1.05rem; font-weight: 700; color: var(--green-channel); margin-bottom: 16px; }
.divider { border: 0; height: 1px; background: var(--glass-border); margin: 16px 0; }
.fact-container { text-align: left; background: rgba(0,0,0,0.15); padding: 12px; border-radius: var(--border-radius-md); margin-bottom: 20px; border: 1px solid var(--glass-border); }
.fact-label { font-size: 0.7rem; text-transform: uppercase; font-weight: 700; color: var(--accent-primary); display: block; margin-bottom: 2px; }
.fact-text { font-size: 0.85rem; line-height: 1.4; color: var(--text-secondary); }

/* Animation Classes */
.animated-pop { animation: popTransform 0.35s cubic-bezier(0.175, 0.885, 0.32, 1.275) forwards; }
@keyframes popTransform {
    0% { transform: scale(0.85) translateY(15px); opacity: 0; }
    100% { transform: scale(1) translateY(0); opacity: 1; }
}

.floating-num {
    position: absolute;
    pointer-events: none;
    font-weight: 800;
    font-size: 1.6rem;
    color: #ffd700;
    text-shadow: 0 3px 6px rgba(0,0,0,0.5);
    z-index: 2000;
    animation: floatUpAndOut 1s cubic-bezier(0.25, 1, 0.5, 1) forwards;
}
@keyframes floatUpAndOut {
    0% { transform: translateY(0) scale(0.8); opacity: 1; }
    100% { transform: translateY(-70px) scale(1.1); opacity: 0; }
}

.summary-list { display: flex; flex-direction: column; gap: 10px; margin-top: 12px; }
.summary-item { display: flex; justify-content: space-between; font-size: 0.98rem; border-bottom: 1px solid rgba(255,255,255,0.05); padding-bottom: 6px; }
.summary-item strong { font-size: 1.05rem; color: #ffd700; }

/* Dynamic Device Responsive Adjustments */
@media (max-width: 480px) {
    body { padding: 12px 10px; }
    .glass-panel { padding: 16px 12px; border-radius: var(--border-radius-md); }
    .game-title { font-size: 2.1rem; }
    .color-box { height: 95px; font-size: 1rem; }
    .sliders-control-group { padding: 12px; gap: 10px; }
    input[type="range"]::-webkit-slider-thumb { width: 28px; height: 28px; } /* Larger finger targets */
    input[type="range"]::-moz-range-thumb { width: 28px; height: 28px; }
    .hud-value { font-size: 0.95rem; }
    .hud-label { font-size: 0.6rem; }
    .main-btn { padding: 11px 16px; font-size: 0.92rem; }
    .mode-selector { flex-direction: column; gap: 8px; }
    .difficulty-selector { gap: 6px; }
    .diff-btn { padding: 8px 12px; }
    .diff-btn .diff-title { font-size: 0.92rem; }
    .diff-btn .diff-desc { font-size: 0.75rem; }
}

/* Height fix targeting short screens */
@media (max-height: 660px) {
    .game-title { font-size: 1.8rem; margin-bottom: 2px; }
    .game-subtitle { margin-bottom: 12px; font-size: 0.85rem; }
    .menu-card { padding: 12px; margin-bottom: 12px; }
    .difficulty-selector { margin-bottom: 12px; }
    .color-box { height: 75px; }
    .hud-bar { margin-bottom: 12px; padding: 6px; }
    .sliders-control-group { margin-bottom: 12px; padding: 10px; }
}