:root {
    --primary-color: #4CAF50;
    --secondary-color: #81C784;
    --background-color: #F5F5F5;
    --text-color: #333333;
    --border-radius: 12px;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

body {
    background-color: var(--background-color);
    color: var(--text-color);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

header {
    background-color: white;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

header h1 {
    color: var(--primary-color);
    margin: 0;
}

.score-container {
    display: flex;
    justify-content: flex-end;
    gap: 2rem;
    font-size: 1.1rem;
}

main {
    flex: 1;
    padding: 2rem;
    display: flex;
    gap: 2rem;
    justify-content: center;
    align-items: stretch;
    flex-wrap: wrap;
}

.game-container {
    background: white;
    padding: 1rem;
    border-radius: var(--border-radius);
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    position: relative;
    width: 552px;
    display: flex;
    flex-direction: column;
}

#gameCanvas {
    background: #FAFAFA;
    border-radius: var(--border-radius);
    display: block;
}

.game-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(255, 255, 255, 0.3);
    backdrop-filter: blur(2px);
    display: flex;
    justify-content: center;
    align-items: center;
    border-radius: var(--border-radius);
    text-align: center;
    z-index: 1;
}

.overlay-content {
    background: white;
    padding: 1.5rem 2.5rem;
    border-radius: var(--border-radius);
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    background: rgba(255, 255, 255, 0.95);
    border: 1px solid rgba(0, 0, 0, 0.1);
}

.overlay-content h3 {
    color: var(--primary-color);
    font-size: 1.5rem;
    margin-bottom: 1rem;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.1);
}

.overlay-content p {
    color: #666;
    line-height: 1.5;
}

.game-settings {
    background: #F8F9FA;
    padding: 1rem;
    border-radius: var(--border-radius);
    margin-bottom: 1rem;
}

.speed-setting {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-top: 0.5rem;
}

.game-instructions {
    background: #F8F9FA;
    padding: 1rem;
    border-radius: var(--border-radius);
    margin-bottom: 1rem;
}

.game-instructions ul {
    list-style: none;
    padding: 0;
    margin-top: 0.5rem;
}

.game-instructions li {
    padding: 0.3rem 0;
    color: #666;
}

.controls {
    margin-top: auto;
    padding-top: 1rem;
    display: flex;
    justify-content: center;
    gap: 1rem;
}

.btn {
    padding: 0.5rem 1.5rem;
    border: none;
    border-radius: var(--border-radius);
    background-color: var(--primary-color);
    color: white;
    cursor: pointer;
    font-size: 1rem;
    transition: transform 0.2s;
    z-index: 2;
    outline: none;
}

.btn:hover {
    transform: translateY(-2px);
}

.btn:focus {
    outline: none;
}

.leaderboard {
    background: white;
    padding: 1rem;
    border-radius: var(--border-radius);
    min-width: 300px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    display: flex;
    flex-direction: column;
}

.leaderboard h2 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    text-align: center;
}

#leaderboardList {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.leaderboard-item {
    display: flex;
    justify-content: space-between;
    padding: 0.5rem;
    background: linear-gradient(to right, #F5F5F5, #FFFFFF);
    border-radius: 6px;
    transition: transform 0.2s;
    border: 1px solid rgba(0, 0, 0, 0.05);
}

.leaderboard-item:hover {
    transform: translateX(5px);
}

.leaderboard-empty {
    text-align: center;
    padding: 1rem;
    color: #666;
    font-style: italic;
}

.leaderboard-item span:first-child {
    font-weight: 500;
    color: var(--primary-color);
}

.leaderboard-item span:last-child {
    color: #666;
    font-size: 0.9em;
}

footer {
    text-align: center;
    padding: 1rem;
    background: white;
    box-shadow: 0 -2px 4px rgba(0,0,0,0.1);
}

footer p {
    color: #666;
    font-size: 0.9rem;
}

.score-container span {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: #666;
}

.score-container span span {
    color: var(--primary-color);
    font-weight: 500;
}