:root {
    --bg-primary: #1a1a2e;
    --bg-secondary: #16213e;
    --bg-tertiary: #0f3460;
    --accent-primary: #e94560;
    --accent-secondary: #ff6b6b;
    --text-primary: #ffffff;
    --text-secondary: #b8b8b8;
    --success: #4ecdc4;
    --warning: #ffe66d;
    --grid-bg: #2d2d44;
    --tile-empty: #3d3d5c;
    --color-1: #e94560;
    --color-2: #4ecdc4;
    --color-3: #ffe66d;
    --color-4: #a8e6cf;
    --color-5: #ff8b94;
    --color-6: #c7ceea;
    --shadow-soft: 0 4px 20px rgba(0,0,0,0.3);
    --shadow-glow: 0 0 30px rgba(233,69,96,0.4);
    --transition-smooth: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
    touch-action: manipulation;
}

html, body {
    height: 100%;
    overflow: hidden;
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
}

#game-container {
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    position: relative;
}

/* Screen Management */
.screen {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: none;
    flex-direction: column;
    opacity: 0;
    transition: opacity 0.4s ease;
    z-index: 10;
}

.screen.active {
    display: flex;
    opacity: 1;
}

/* Start Screen */
#start-screen {
    background: linear-gradient(135deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.logo-container {
    text-align: center;
    margin-bottom: 40px;
}

.game-title {
    font-size: clamp(2.5rem, 10vw, 4rem);
    font-weight: 800;
    background: linear-gradient(135deg, var(--color-1), var(--color-2), var(--color-3));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-shadow: none;
    letter-spacing: -2px;
    animation: titlePulse 3s ease-in-out infinite;
}

@keyframes titlePulse {
    0%, 100% { filter: brightness(1); }
    50% { filter: brightness(1.2); }
}

.tagline {
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-top: 10px;
}

.menu-buttons {
    display: flex;
    flex-direction: column;
    gap: 15px;
    width: 100%;
    max-width: 300px;
}

.btn {
    padding: 18px 40px;
    border: none;
    border-radius: 50px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition-smooth);
    text-transform: uppercase;
    letter-spacing: 1px;
}

.btn-primary {
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    color: white;
    box-shadow: var(--shadow-glow);
}

.btn-primary:hover, .btn-primary:active {
    transform: translateY(-3px) scale(1.02);
    box-shadow: 0 8px 30px rgba(233,69,96,0.5);
}

.btn-secondary {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border: 2px solid var(--bg-tertiary);
}

.btn-secondary:hover, .btn-secondary:active {
    background: var(--bg-secondary);
    border-color: var(--accent-primary);
}

.btn-small {
    padding: 12px 24px;
    font-size: 0.9rem;
}

/* Game Screen */
#game-screen {
    background: var(--bg-primary);
}

.game-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 20px;
    background: var(--bg-secondary);
    box-shadow: var(--shadow-soft);
}

.level-info {
    display: flex;
    flex-direction: column;
    gap: 5px;
}

.level-number {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--accent-primary);
}

.score-display {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.game-controls {
    display: flex;
    gap: 10px;
}

.icon-btn {
    width: 44px;
    height: 44px;
    border-radius: 50%;
    border: none;
    background: var(--bg-tertiary);
    color: var(--text-primary);
    font-size: 1.2rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition-smooth);
}

.icon-btn:hover, .icon-btn:active {
    background: var(--accent-primary);
    transform: scale(1.1);
}

/* Banner Ad Area */
.ad-banner-area {
    width: 100%;
    min-height: 50px;
    background: var(--bg-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    border-bottom: 1px solid var(--bg-tertiary);
}

.ad-placeholder {
    color: var(--text-secondary);
    font-size: 0.75rem;
    padding: 5px 15px;
    background: var(--bg-tertiary);
    border-radius: 4px;
}

/* Game Board */
.game-board-container {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 20px;
    position: relative;
}

#game-canvas {
    border-radius: 16px;
    box-shadow: var(--shadow-soft);
    max-width: 100%;
    max-height: calc(100% - 100px);
}

/* Color Palette */
.color-palette {
    display: flex;
    gap: 10px;
    padding: 15px;
    background: var(--bg-secondary);
    border-radius: 50px;
    margin-top: 15px;
    box-shadow: var(--shadow-soft);
}

.color-btn {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    border: 4px solid transparent;
    cursor: pointer;
    transition: var(--transition-smooth);
    position: relative;
}

.color-btn::after {
    content: '';
    position: absolute;
    inset: -4px;
    border-radius: 50%;
    border: 2px solid transparent;
    transition: var(--transition-smooth);
}

.color-btn.selected {
    transform: scale(1.15);
    box-shadow: 0 0 20px currentColor;
}

.color-btn.selected::after {
    border-color: white;
}

.color-btn.locked {
    opacity: 0.3;
    cursor: not-allowed;
}

/* Moves Counter */
.moves-counter {
    position: absolute;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--bg-tertiary);
    padding: 10px 25px;
    border-radius: 25px;
    font-weight: 600;
    box-shadow: var(--shadow-soft);
}

.moves-counter.warning {
    color: var(--warning);
    animation: pulse 1s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { transform: translateX(-50%) scale(1); }
    50% { transform: translateX(-50%) scale(1.05); }
}

/* Modal Overlays */
.modal-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.8);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 100;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.modal-overlay.active {
    display: flex;
    opacity: 1;
}

.modal-content {
    background: var(--bg-secondary);
    border-radius: 24px;
    padding: 40px;
    text-align: center;
    max-width: 90%;
    width: 350px;
    box-shadow: var(--shadow-soft);
    transform: scale(0.9);
    transition: transform 0.3s ease;
}

.modal-overlay.active .modal-content {
    transform: scale(1);
}

.modal-title {
    font-size: 1.8rem;
    margin-bottom: 20px;
    color: var(--text-primary);
}

.modal-text {
    color: var(--text-secondary);
    margin-bottom: 25px;
    line-height: 1.6;
}

.modal-text p {
    margin-bottom: 10px;
}

.modal-buttons {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

/* Level Complete Screen */
.stars-container {
    display: flex;
    gap: 15px;
    justify-content: center;
    margin: 20px 0;
}

.star {
    font-size: 3rem;
    color: var(--bg-tertiary);
    transition: all 0.5s ease;
    transform: scale(0);
}

.star.earned {
    color: var(--warning);
    transform: scale(1);
    animation: starPop 0.5s ease;
}

@keyframes starPop {
    0% { transform: scale(0) rotate(-180deg); }
    50% { transform: scale(1.3) rotate(10deg); }
    100% { transform: scale(1) rotate(0deg); }
}

.stats-row {
    display: flex;
    justify-content: space-around;
    margin: 20px 0;
    padding: 15px;
    background: var(--bg-tertiary);
    border-radius: 12px;
}

.stat {
    text-align: center;
}

.stat-value {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--accent-primary);
}

.stat-label {
    font-size: 0.8rem;
    color: var(--text-secondary);
    text-transform: uppercase;
}

/* Settings Panel */
.settings-grid {
    display: grid;
    gap: 15px;
    margin: 20px 0;
}

.setting-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px;
    background: var(--bg-tertiary);
    border-radius: 12px;
}

.setting-label {
    display: flex;
    align-items: center;
    gap: 10px;
}

.toggle {
    width: 50px;
    height: 28px;
    background: var(--bg-primary);
    border-radius: 14px;
    position: relative;
    cursor: pointer;
    transition: var(--transition-smooth);
}

.toggle.active {
    background: var(--success);
}

.toggle::after {
    content: '';
    position: absolute;
    width: 24px;
    height: 24px;
    background: white;
    border-radius: 50%;
    top: 2px;
    left: 2px;
    transition: var(--transition-smooth);
}

.toggle.active::after {
    left: 24px;
}

/* Particles */
.particle {
    position: absolute;
    pointer-events: none;
    border-radius: 50%;
    animation: particleFloat 1s ease-out forwards;
}

@keyframes particleFloat {
    0% {
        transform: translate(0, 0) scale(1);
        opacity: 1;
    }
    100% {
        transform: translate(var(--tx), var(--ty)) scale(0);
        opacity: 0;
    }
}

/* Responsive */
@media (max-width: 480px) {
    .color-btn {
        width: 45px;
        height: 45px;
    }
    
    .color-palette {
        gap: 8px;
        padding: 12px;
    }
    
    .modal-content {
        padding: 30px 20px;
    }
}

@media (min-width: 768px) {
    .game-board-container {
        padding: 40px;
    }
}

/* Reduced Motion */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

.reduced-motion * {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
}

/* Debug Mode */
.debug-info {
    position: fixed;
    bottom: 5px;
    right: 5px;
    background: rgba(0,0,0,0.7);
    color: #0f0;
    font-family: monospace;
    font-size: 10px;
    padding: 5px;
    border-radius: 4px;
    display: none;
    z-index: 1000;
}

.debug-mode .debug-info {
    display: block;
}