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

body {
    font-family: Arial, sans-serif;
    background-color: #111;
    color: #eee;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

.game-container {
    display: flex;
    gap: 20px;
    padding: 20px;
    background-color: #222;
    border-radius: 8px;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.5);
}

.sidebar {
    width: 220px;
}

.stats, .skills, .inventory {
    margin-bottom: 20px;
    padding: 10px;
    background-color: #333;
    border-radius: 5px;
}

.stats h2, .skills h2, .inventory h2 {
    margin-bottom: 10px;
    color: #4CAF50;
}

.game-area {
    display: flex;
    flex-direction: column;
    align-items: center;
}

#tetris {
    background-color: #000;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.8);
    border: 2px solid #333;
}

.next-piece {
    margin-top: 20px;
    padding: 10px;
    background-color: #333;
    border-radius: 5px;
    text-align: center;
}

.next-piece h3 {
    margin-bottom: 10px;
    color: #4CAF50;
}

#next-piece {
    background-color: #000;
}

.skill-tree {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 8px;
}

.skill {
    padding: 8px;
    background-color: #444;
    border-radius: 4px;
    text-align: center;
    cursor: pointer;
    transition: background-color 0.2s;
}

.skill:hover {
    background-color: #555;
}

.skill.unlocked {
    background-color: #2E7D32;
}

.skill.available {
    background-color: #666;
    border: 1px solid #4CAF50;
}

#inventory-slots {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 8px;
}

.inventory-slot {
    width: 100%;
    aspect-ratio: 1;
    background-color: #444;
    border-radius: 4px;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 24px;
}

.inventory-slot.filled {
    background-color: #333;
    border: 1px solid #777;
}

/* Sound controls */
.sound-controls {
    position: absolute;
    top: 10px;
    right: 10px;
    display: flex;
    align-items: center;
    gap: 10px;
    background-color: rgba(0, 0, 0, 0.7);
    padding: 8px 12px;
    border-radius: 5px;
    z-index: 10;
    border: 1px solid #4CAF50;
    box-shadow: 0 0 10px rgba(76, 175, 80, 0.5);
}

.sound-controls button {
    background: #333;
    border: 1px solid #4CAF50;
    color: #fff;
    font-size: 20px;
    cursor: pointer;
    padding: 2px 8px;
    border-radius: 4px;
    transition: all 0.2s ease;
}

.sound-controls button:hover {
    background: #444;
    transform: scale(1.05);
}

.sound-controls input[type="range"] {
    width: 80px;
    background-color: #444;
    height: 8px;
    outline: none;
    -webkit-appearance: none;
    border-radius: 5px;
    cursor: pointer;
    transition: all 0.2s ease;
}

.sound-controls input[type="range"]:hover {
    background-color: #555;
}

.sound-controls input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 16px;
    height: 16px;
    background-color: #4CAF50;
    border-radius: 50%;
    cursor: pointer;
    box-shadow: 0 0 5px rgba(0, 0, 0, 0.5);
}

/* Firefox */
.sound-controls input[type="range"]::-moz-range-thumb {
    width: 16px;
    height: 16px;
    background-color: #4CAF50;
    border-radius: 50%;
    cursor: pointer;
    border: none;
    box-shadow: 0 0 5px rgba(0, 0, 0, 0.5);
}

/* Edge and IE */
.sound-controls input[type="range"]::-ms-thumb {
    width: 16px;
    height: 16px;
    background-color: #4CAF50;
    border-radius: 50%;
    cursor: pointer;
    box-shadow: 0 0 5px rgba(0, 0, 0, 0.5);
}

/* Sound effect animations */
@keyframes flash {
    0% { opacity: 0.5; }
    50% { opacity: 1; }
    100% { opacity: 0.5; }
}

.tetris-flash {
    animation: flash 0.3s ease-out;
}

/* Start button */
.start-button {
    background-color: #4CAF50;
    color: white;
    border: none;
    padding: 15px 32px;
    text-align: center;
    text-decoration: none;
    display: inline-block;
    font-size: 18px;
    margin: 4px 2px;
    cursor: pointer;
    border-radius: 8px;
    box-shadow: 0 6px 10px rgba(0, 0, 0, 0.3);
    transition: all 0.3s ease;
}

.start-button:hover {
    background-color: #45a049;
    transform: translateY(-2px);
    box-shadow: 0 8px 15px rgba(0, 0, 0, 0.4);
}

.start-button:active {
    background-color: #3e8e41;
    transform: translateY(1px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.3);
}