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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #0f0c29, #302b63, #24243e);
    color: #fff;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

header {
    background: rgba(0, 0, 0, 0.3);
    backdrop-filter: blur(10px);
    padding: 1rem 2rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    background: linear-gradient(45deg, #00ff88, #00bbff);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-links a {
    color: #fff;
    text-decoration: none;
    transition: color 0.3s;
}

.nav-links a:hover {
    color: #00ff88;
}

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

#gameContainer {
    position: relative;
    width: 100%;
    max-width: 900px;
    height: 600px;
}

.screen {
    position: absolute;
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    background: rgba(0, 0, 0, 0.5);
    border-radius: 20px;
    backdrop-filter: blur(5px);
    padding: 2rem;
}

.screen.hidden {
    display: none;
}

#startScreen h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
    background: linear-gradient(45deg, #ff006e, #8338ec, #3a86ff);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

#startScreen p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    opacity: 0.8;
}

.menu-buttons {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    margin-bottom: 2rem;
}

.primary-btn, .secondary-btn {
    padding: 1rem 2rem;
    font-size: 1.1rem;
    border: none;
    border-radius: 50px;
    cursor: pointer;
    transition: all 0.3s;
    font-weight: bold;
}

.primary-btn {
    background: linear-gradient(45deg, #00ff88, #00bbff);
    color: #000;
}

.primary-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(0, 255, 136, 0.3);
}

.secondary-btn {
    background: rgba(255, 255, 255, 0.1);
    color: #fff;
    border: 2px solid rgba(255, 255, 255, 0.2);
}

.secondary-btn:hover {
    background: rgba(255, 255, 255, 0.2);
}

.high-score {
    font-size: 1.2rem;
    opacity: 0.8;
}

#gameScreen {
    padding: 0;
}

.game-ui {
    position: absolute;
    top: 20px;
    left: 20px;
    right: 20px;
    display: flex;
    justify-content: space-between;
    z-index: 10;
    font-size: 1.1rem;
    font-weight: bold;
}

.game-ui span {
    background: rgba(0, 0, 0, 0.5);
    padding: 0.5rem 1rem;
    border-radius: 10px;
    backdrop-filter: blur(5px);
}

#gameCanvas {
    border-radius: 20px;
    background: #000;
}

.game-over-overlay, .level-complete-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.9);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    border-radius: 20px;
}

.game-over-overlay h2, .level-complete-overlay h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.game-over-overlay p, .level-complete-overlay p {
    font-size: 1.5rem;
    margin-bottom: 2rem;
}

.instructions-content {
    display: grid;
    gap: 1rem;
    margin-bottom: 2rem;
}

.instruction-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    font-size: 1.1rem;
}

.key {
    background: rgba(255, 255, 255, 0.1);
    padding: 0.5rem 1rem;
    border-radius: 5px;
    font-weight: bold;
    min-width: 80px;
    text-align: center;
}

.power-ups-info {
    margin-bottom: 2rem;
}

.power-ups-info h3 {
    margin-bottom: 1rem;
    text-align: center;
}

.power-up-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 0.5rem;
}

.power-up-icon {
    width: 30px;
    height: 30px;
    border-radius: 50%;
}

.rapid-fire {
    background: linear-gradient(45deg, #ff006e, #ff4458);
}

.triple-shot {
    background: linear-gradient(45deg, #3a86ff, #00bbff);
}

.shield {
    background: linear-gradient(45deg, #00ff88, #00d68f);
}

.life {
    background: linear-gradient(45deg, #ff6b6b, #ff8787);
}

.leaderboard-list {
    width: 100%;
    max-width: 400px;
    margin-bottom: 2rem;
}

.leaderboard-entry {
    display: flex;
    justify-content: space-between;
    padding: 1rem;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 10px;
    margin-bottom: 0.5rem;
}

.leaderboard-entry:first-child {
    background: linear-gradient(45deg, #ffd700, #ffed4e);
    color: #000;
}

footer {
    text-align: center;
    padding: 1rem;
    background: rgba(0, 0, 0, 0.3);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

@media (max-width: 768px) {
    .nav-links {
        gap: 1rem;
        font-size: 0.9rem;
    }
    
    #gameContainer {
        height: 500px;
    }
    
    #startScreen h1 {
        font-size: 2rem;
    }
    
    .game-ui {
        font-size: 0.9rem;
    }
}