body, html {
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
    background: linear-gradient(to bottom, #87CEEB 0%, #E0F6FF 50%, #1E90FF 50%, #00008B 100%);
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    touch-action: none;
    user-select: none;
    -webkit-user-select: none;
}

#ui-layer {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    z-index: 10;
}

#score-display {
    padding: 15px 20px;
    font-size: 1.5rem;
    font-weight: 900;
    color: #fff;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.8);
    text-align: left;
    background: rgba(0,0,0,0.3);
    border-bottom-right-radius: 15px;
    display: inline-block;
    align-self: flex-start;
}

#start-screen, #game-over {
    position: absolute;
    top: 45%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: rgba(15, 32, 39, 0.95);
    color: white;
    padding: 30px;
    border-radius: 15px;
    text-align: center;
    border: 3px solid #f4a261;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.8);
    pointer-events: auto;
    cursor: pointer;
    min-width: 250px;
}

#game-over {
    border-color: #e63946;
}

h1 {
    margin-top: 0;
    font-size: 2.2rem;
    text-transform: uppercase;
    letter-spacing: 2px;
}

#game-over h1 {
    color: #e63946;
}

#start-screen h1 {
    color: #f4a261;
}

p {
    font-size: 1.1rem;
    margin: 10px 0;
}

.blink {
    animation: blinker 1.5s linear infinite;
    font-weight: bold;
    margin-top: 25px;
    color: #2a9d8f;
    font-size: 1.2rem;
    text-transform: uppercase;
}

@keyframes blinker {
    50% { opacity: 0.3; }
}

.hidden {
    display: none !important;
}

canvas {
    display: block;
    width: 100%;
    height: 100%;
    position: absolute;
    top: 0;
    left: 0;
    z-index: 1;
}