:root {
    --color-blue: #0000FF;
    --color-red: #FF0000;
    --color-yellow: #FFFF00;
    --color-green: #00FF00;
    
    --bg: #ffffff;
    --text: #000000;
    --text-secondary: #666666;
    --border: #e5e5e5;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', sans-serif;
    background: var(--bg);
    color: var(--text);
    height: 100vh;
    overflow: hidden;
    -webkit-font-smoothing: antialiased;
}

.app-container {
    height: 100vh;
    display: flex;
    flex-direction: column;
    position: relative;
    padding: 30px;
}

/* Branding */
.branding {
    position: absolute;
    top: 30px;
    left: 30px;
    font-size: 18px;
    font-weight: 600;
    color: var(--text);
    letter-spacing: -0.02em;
    z-index: 10;
}

/* Scoreboard - Top Right */
.scoreboard {
    position: absolute;
    top: 30px;
    right: 30px;
    display: flex;
    gap: 40px;
    z-index: 10;
}

.score-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
}

.score-value {
    font-size: 48px;
    font-weight: 700;
    color: var(--text);
    line-height: 1;
}

.score-label {
    font-size: 12px;
    font-weight: 500;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* Game Container */
.game-container {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 40px;
}

.game-board {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
}

.tile {
    width: 180px;
    height: 180px;
    border-radius: 20px;
    cursor: pointer;
    position: relative;
    transition: all 0.15s ease;
    user-select: none;
}

.tile-inner {
    width: 100%;
    height: 100%;
    border-radius: 20px;
    transition: all 0.15s ease;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.tile[data-color="0"] .tile-inner {
    background: var(--color-blue);
}

.tile[data-color="1"] .tile-inner {
    background: var(--color-red);
}

.tile[data-color="2"] .tile-inner {
    background: var(--color-yellow);
}

.tile[data-color="3"] .tile-inner {
    background: var(--color-green);
}

.tile:hover:not(.disabled) {
    transform: scale(1.05);
}

.tile:hover:not(.disabled) .tile-inner {
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.2);
}

.tile:active:not(.disabled) {
    transform: scale(0.95);
}

.tile.active {
    transform: scale(1.1);
}

.tile.active .tile-inner {
    filter: brightness(1.5);
    box-shadow: 0 0 50px currentColor, 0 8px 32px rgba(0, 0, 0, 0.3);
}

.tile[data-color="0"].active .tile-inner {
    box-shadow: 0 0 50px var(--color-blue), 0 8px 32px rgba(0, 0, 0, 0.3);
}

.tile[data-color="1"].active .tile-inner {
    box-shadow: 0 0 50px var(--color-red), 0 8px 32px rgba(0, 0, 0, 0.3);
}

.tile[data-color="2"].active .tile-inner {
    box-shadow: 0 0 50px var(--color-yellow), 0 8px 32px rgba(0, 0, 0, 0.3);
}

.tile[data-color="3"].active .tile-inner {
    box-shadow: 0 0 50px var(--color-green), 0 8px 32px rgba(0, 0, 0, 0.3);
}

.tile.disabled {
    cursor: not-allowed;
    opacity: 0.5;
}

.tile.error .tile-inner {
    animation: shake 0.4s ease;
    filter: brightness(0.4);
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-12px); }
    75% { transform: translateX(12px); }
}

/* Info Panel */
.info-panel {
    text-align: center;
    width: 400px;
}

.status-text {
    font-size: 16px;
    font-weight: 600;
    color: var(--text);
    margin-bottom: 16px;
    min-height: 24px;
}

.progress-bar {
    width: 100%;
    height: 8px;
    background: var(--border);
    border-radius: 4px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: var(--text);
    border-radius: 4px;
    transition: width 0.3s ease;
    width: 0%;
}

/* Controls */
.controls {
    display: flex;
    gap: 16px;
    margin-top: 20px;
}

.btn {
    padding: 16px 40px;
    border-radius: 12px;
    border: 3px solid var(--text);
    font-size: 16px;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.2s ease;
    font-family: inherit;
    min-width: 160px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.btn-primary {
    background: var(--text);
    color: var(--bg);
}

.btn-primary:hover:not(:disabled) {
    transform: translateY(-3px);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
}

.btn-secondary {
    background: var(--bg);
    color: var(--text);
}

.btn-secondary:hover:not(:disabled) {
    background: var(--text);
    color: var(--bg);
    transform: translateY(-3px);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
}

.btn:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.btn:active:not(:disabled) {
    transform: translateY(-1px);
}

.btn-large {
    width: 100%;
    padding: 18px;
    font-size: 18px;
}

/* Modal */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(10px);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease;
    z-index: 1000;
}

.modal.active {
    opacity: 1;
    pointer-events: all;
}

.modal-content {
    background: var(--bg);
    border-radius: 24px;
    padding: 48px;
    max-width: 480px;
    width: 90%;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    text-align: center;
    transform: scale(0.9);
    transition: transform 0.3s ease;
    border: 3px solid var(--text);
}

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

.modal-content h2 {
    font-size: 32px;
    margin-bottom: 16px;
    color: var(--text);
    font-weight: 700;
    letter-spacing: -0.02em;
}

.modal-content p {
    font-size: 16px;
    color: var(--text-secondary);
    margin-bottom: 32px;
    line-height: 1.6;
}

/* Responsive */
@media (max-width: 768px) {
    .app-container {
        padding: 20px;
    }
    
    .branding {
        top: 20px;
        left: 20px;
        font-size: 14px;
    }
    
    .scoreboard {
        top: 60px;
        right: 20px;
        gap: 24px;
    }
    
    .score-value {
        font-size: 36px;
    }
    
    .score-label {
        font-size: 10px;
    }
    
    .game-board {
        gap: 16px;
        margin-top: 20px;
    }
    
    .tile {
        width: 140px;
        height: 140px;
    }
    
    .info-panel {
        width: 100%;
        max-width: 320px;
    }
    
    .controls {
        flex-direction: column;
        width: 100%;
        max-width: 320px;
    }
    
    .btn {
        width: 100%;
        padding: 14px;
        font-size: 14px;
        min-width: auto;
    }
}

@media (max-width: 480px) {
    .scoreboard {
        gap: 16px;
        flex-direction: row;
    }
    
    .score-value {
        font-size: 28px;
    }
    
    .tile {
        width: 120px;
        height: 120px;
    }
}