@import url('https://fonts.googleapis.com/css2?family=Orbitron:wght@400;700;900&display=swap');

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

html, body {
    width: 100%;
    height: 100%;
    overflow: hidden;
    background: #1a0a2e;
    font-family: 'Orbitron', monospace;
    touch-action: none;
}

#gameCanvas {
    display: block;
    width: 100%;
    height: 100%;
}

#ui {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 100;
}

#score {
    position: absolute;
    top: 20px;
    left: 30px;
    color: #00ffff;
    font-size: 32px;
    font-weight: 700;
    text-shadow: 0 0 10px #00ffff, 0 0 20px #00ffff, 0 0 40px #00ffff;
    letter-spacing: 2px;
    animation: glow-pulse 2s ease-in-out infinite;
}

@keyframes glow-pulse {
    0%, 100% { text-shadow: 0 0 10px #00ffff, 0 0 20px #00ffff, 0 0 40px #00ffff; }
    50% { text-shadow: 0 0 15px #00ffff, 0 0 30px #00ffff, 0 0 60px #00ffff, 0 0 80px #00ffff; }
}

#highScore {
    position: absolute;
    top: 25px;
    right: 30px;
    color: #ff00ff;
    font-size: 18px;
    font-weight: 400;
    text-shadow: 0 0 8px #ff00ff, 0 0 16px #ff00ff;
    letter-spacing: 1px;
}

.overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(26, 10, 46, 0.92);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    pointer-events: auto;
    transition: opacity 0.4s ease;
}

.overlay.hidden {
    opacity: 0;
    pointer-events: none;
}

#startScreen h1 {
    font-size: clamp(36px, 10vw, 72px);
    font-weight: 900;
    color: #00ffff;
    text-shadow: 0 0 20px #00ffff, 0 0 40px #00ffff, 0 0 80px #00ffff;
    margin-bottom: 15px;
    letter-spacing: 4px;
    animation: title-glow 2s ease-in-out infinite;
}

@keyframes title-glow {
    0%, 100% { 
        transform: scale(1);
        text-shadow: 0 0 20px #00ffff, 0 0 40px #00ffff, 0 0 80px #00ffff;
    }
    50% { 
        transform: scale(1.03);
        text-shadow: 0 0 30px #00ffff, 0 0 60px #00ffff, 0 0 100px #00ffff, 0 0 120px #00ffff;
    }
}

#startScreen p {
    font-size: clamp(14px, 3vw, 20px);
    color: #ff00ff;
    text-shadow: 0 0 10px #ff00ff;
    margin-bottom: 35px;
    letter-spacing: 3px;
}

.start-btn {
    padding: 18px 50px;
    font-size: clamp(18px, 4vw, 26px);
    font-family: 'Orbitron', monospace;
    font-weight: 700;
    color: #1a0a2e;
    background: linear-gradient(135deg, #00ffff, #ff00ff);
    border: none;
    cursor: pointer;
    letter-spacing: 3px;
    transition: all 0.3s ease;
    box-shadow: 0 0 20px #00ffff, 0 0 40px #ff00ff;
    border-radius: 4px;
    position: relative;
    overflow: hidden;
}

.start-btn::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: linear-gradient(
        45deg,
        transparent,
        rgba(255, 255, 255, 0.3),
        transparent
    );
    transform: rotate(45deg) translateX(-100%);
    transition: transform 0.6s ease;
}

.start-btn:hover {
    transform: scale(1.08);
    box-shadow: 0 0 30px #00ffff, 0 0 60px #ff00ff;
}

.start-btn:hover::before {
    transform: rotate(45deg) translateX(100%);
}

.start-btn:active {
    transform: scale(0.98);
}

#gameOverScreen h2 {
    font-size: clamp(32px, 8vw, 56px);
    font-weight: 900;
    color: #ff3333;
    text-shadow: 0 0 20px #ff3333, 0 0 40px #ff3333;
    margin-bottom: 25px;
    letter-spacing: 4px;
    animation: shake 0.5s ease-in-out;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    20% { transform: translateX(-10px); }
    40% { transform: translateX(10px); }
    60% { transform: translateX(-10px); }
    80% { transform: translateX(10px); }
}

#gameOverScreen .final-score {
    font-size: clamp(24px, 6vw, 40px);
    color: #00ffff;
    text-shadow: 0 0 15px #00ffff;
    margin-bottom: 12px;
}

#gameOverScreen .final-high {
    font-size: clamp(16px, 3vw, 24px);
    color: #ffd700;
    text-shadow: 0 0 10px #ffd700;
    margin-bottom: 35px;
}

.controls-hint {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    color: #888;
    font-size: 14px;
    letter-spacing: 1px;
    text-align: center;
}

/* Mobile optimizations */
@media (max-width: 600px) {
    #score {
        top: 15px;
        left: 20px;
        font-size: 24px;
    }
    
    #highScore {
        top: 18px;
        right: 20px;
        font-size: 14px;
    }
    
    .controls-hint {
        font-size: 12px;
        padding: 0 20px;
    }
}

/* Scanline effect overlay */
#ui::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: repeating-linear-gradient(
        0deg,
        transparent,
        transparent 2px,
        rgba(0, 0, 0, 0.03) 2px,
        rgba(0, 0, 0, 0.03) 4px
    );
    pointer-events: none;
}