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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    overflow: hidden;
    background: #0a0e27;
    color: #fff;
}

#canvas {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    cursor: crosshair;
    z-index: 1;
}

#ui-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 2;
}

#ui-overlay > * {
    pointer-events: auto;
}

#header {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    background: linear-gradient(180deg, rgba(0,0,0,0.8) 0%, rgba(0,0,0,0) 100%);
    padding: 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

h1 {
    font-family: 'Georgia', serif;
    font-size: 2.5em;
    text-shadow: 0 0 10px #ffd700, 0 0 20px #ffd700;
    letter-spacing: 2px;
}

#stats {
    display: flex;
    gap: 30px;
    font-family: 'Courier New', monospace;
    font-size: 1.3em;
}

#points-display {
    font-weight: bold;
    text-shadow: 0 0 5px #fff;
}

#pps-display {
    color: #90ee90;
}

#mute-btn {
    background: rgba(255,255,255,0.1);
    border: 2px solid rgba(255,255,255,0.3);
    border-radius: 50%;
    width: 50px;
    height: 50px;
    font-size: 24px;
    cursor: pointer;
    transition: all 0.2s;
}

#mute-btn:hover {
    background: rgba(255,255,255,0.2);
    transform: scale(1.1);
}

#game-container {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    pointer-events: none;
}

#combo-display {
    position: absolute;
    top: 150px;
    left: 50%;
    transform: translateX(-50%);
    font-size: 3em;
    font-weight: bold;
    color: #ffd700;
    text-shadow: 0 0 20px #ffd700, 0 0 40px #ffd700;
    animation: pulse 0.5s infinite alternate;
}

#combo-display.hidden {
    display: none;
}

@keyframes pulse {
    from { transform: translateX(-50%) scale(1); }
    to { transform: translateX(-50%) scale(1.1); }
}

#upgrades-panel {
    position: absolute;
    right: 20px;
    top: 120px;
    bottom: 60px;
    width: 350px;
    background: rgba(0, 0, 0, 0.85);
    border: 2px solid rgba(255, 215, 0, 0.3);
    border-radius: 10px;
    padding: 20px;
    overflow-y: auto;
    pointer-events: auto;
}

#upgrades-panel h2 {
    margin-bottom: 15px;
    text-align: center;
    color: #ffd700;
    text-shadow: 0 0 10px #ffd700;
}

#upgrades-panel h3 {
    margin: 20px 0 10px 0;
    color: #c0c0c0;
    font-size: 1em;
    border-bottom: 1px solid rgba(255,255,255,0.2);
    padding-bottom: 5px;
}

.upgrade-section {
    margin-bottom: 20px;
}

.upgrade {
    display: flex;
    align-items: center;
    gap: 10px;
    background: rgba(45, 27, 105, 0.3);
    border: 2px solid rgba(192, 192, 192, 0.3);
    border-radius: 8px;
    padding: 12px;
    margin-bottom: 10px;
    cursor: pointer;
    transition: all 0.2s;
}

.upgrade:hover {
    background: rgba(45, 27, 105, 0.5);
    transform: translateX(-5px);
}

.upgrade.affordable {
    border-color: #ffd700;
    box-shadow: 0 0 15px rgba(255, 215, 0, 0.5);
    animation: glow 1s infinite alternate;
}

@keyframes glow {
    from { box-shadow: 0 0 10px rgba(255, 215, 0, 0.3); }
    to { box-shadow: 0 0 20px rgba(255, 215, 0, 0.7); }
}

.upgrade-icon {
    font-size: 2em;
    min-width: 40px;
    text-align: center;
}

.upgrade-info {
    flex: 1;
}

.upgrade-name {
    font-weight: bold;
    font-size: 1.1em;
    margin-bottom: 3px;
}

.upgrade-desc {
    font-size: 0.9em;
    color: #90ee90;
}

.upgrade-level {
    font-size: 0.8em;
    color: #c0c0c0;
    margin-top: 3px;
}

.upgrade-cost {
    font-weight: bold;
    font-size: 1.2em;
    color: #ffd700;
    font-family: 'Courier New', monospace;
    min-width: 80px;
    text-align: right;
}

#stats-panel {
    margin-top: 20px;
    padding: 15px;
    background: rgba(0, 0, 0, 0.5);
    border-radius: 8px;
}

#stats-panel h3 {
    margin: 0 0 10px 0;
}

.stat-row {
    display: flex;
    justify-content: space-between;
    padding: 5px 0;
    font-size: 0.9em;
}

.stat-row span {
    color: #ffd700;
    font-weight: bold;
}

#footer {
    position: absolute;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    text-align: center;
    font-size: 0.9em;
    color: rgba(255, 255, 255, 0.6);
    pointer-events: auto;
}

#footer a {
    color: #ffd700;
    text-decoration: none;
}

#footer a:hover {
    text-decoration: underline;
}

#achievement-container {
    position: fixed;
    top: 100px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 1000;
    pointer-events: none;
}

.achievement-popup {
    background: linear-gradient(135deg, #ffd700, #ffed4e);
    color: #000;
    padding: 15px 30px;
    border-radius: 10px;
    font-size: 1.3em;
    font-weight: bold;
    box-shadow: 0 0 30px rgba(255, 215, 0, 0.8);
    margin-bottom: 10px;
    opacity: 0;
    transform: translateY(-20px);
    transition: all 0.3s;
}

.achievement-popup.show {
    opacity: 1;
    transform: translateY(0);
}

/* Mobile styles */
@media (max-width: 768px) {
    h1 {
        font-size: 1.5em;
    }
    
    #stats {
        font-size: 0.9em;
        gap: 15px;
    }
    
    #upgrades-panel {
        width: 90%;
        left: 5%;
        right: auto;
        top: auto;
        bottom: 80px;
        max-height: 40%;
    }
    
    #combo-display {
        font-size: 2em;
        top: 100px;
    }
}

/* Scrollbar styling */
#upgrades-panel::-webkit-scrollbar {
    width: 8px;
}

#upgrades-panel::-webkit-scrollbar-track {
    background: rgba(0, 0, 0, 0.3);
}

#upgrades-panel::-webkit-scrollbar-thumb {
    background: rgba(255, 215, 0, 0.5);
    border-radius: 4px;
}

#upgrades-panel::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 215, 0, 0.7);
}