:root {
    --bg-color: #1a1d21;
    --board-bg-color: #101214;
    --text-color: #e0e0e0;
    --header-color: #ffffff;
    --accent-color: #4a90e2;
    --info-box-bg: #2c313a;
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: var(--font-family);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
}

.game-container {
    width: 100%;
    max-width: 600px;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.game-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.game-header h1 {
    color: var(--header-color);
    font-size: 2.5rem;
    margin: 0;
}

.back-link {
    background-color: var(--info-box-bg);
    color: var(--text-color);
    padding: 10px 15px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: bold;
    transition: background-color 0.2s;
}

.back-link:hover {
    background-color: #454c5a;
}

.game-body {
    display: flex;
    gap: 20px;
}

.game-board-container {
    position: relative;
    border: 4px solid var(--info-box-bg);
    border-radius: 8px;
    overflow: hidden;
}

#tetris-board {
    display: block;
    background-color: var(--board-bg-color);
}

.game-info {
    display: flex;
    flex-direction: column;
    gap: 15px;
    width: 150px;
}

.info-box {
    background-color: var(--info-box-bg);
    padding: 15px;
    border-radius: 8px;
    text-align: center;
}

.info-box h3 {
    margin: 0 0 10px;
    font-size: 1.2rem;
    opacity: 0.8;
}

.info-box p {
    margin: 0;
    font-size: 1.8rem;
    font-weight: bold;
}

.next-piece-box canvas {
    background-color: var(--board-bg-color);
    border-radius: 4px;
}

#start-button, #restart-button {
    background-color: var(--accent-color);
    color: var(--header-color);
    border: none;
    border-radius: 8px;
    padding: 15px;
    font-size: 1.2rem;
    font-weight: bold;
    cursor: pointer;
    width: 100%;
    transition: background-color 0.2s;
}

#start-button:hover, #restart-button:hover {
    background-color: #3a80d2;
}

#game-over-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.75);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 20px;
}

.game-over-text {
    font-size: 2.5rem;
    font-weight: bold;
    color: var(--header-color);
}

#game-over-overlay.hidden {
    display: none;
}