:root {
    --bg-color: #134E4A;
    --primary-color: #14B8A6;
    --secondary-color: #2DD4BF;
    --accent-color: #99F6E4;
    --text-color: #F0FDFA;
    --overlay-bg: rgba(19, 78, 74, 0.9);
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    overflow: hidden;
}

#game-container {
    position: relative;
    width: 100%;
    max-width: 600px;
    height: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
}

header {
    width: 100%;
    padding: 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    z-index: 10;
}

.score-board {
    font-size: 1.2rem;
    font-weight: bold;
    display: flex;
    gap: 15px;
}

.controls {
    display: flex;
    align-items: center;
    gap: 10px;
}

.controls button {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid var(--secondary-color);
    color: var(--text-color);
    padding: 8px 12px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: background 0.2s;
}

.controls button:hover {
    background: rgba(255, 255, 255, 0.2);
}

canvas {
    max-width: 90%;
    max-height: 80vh;
    aspect-ratio: 1;
    border-radius: 50%;
    box-shadow: 0 0 20px rgba(0,0,0,0.3);
    cursor: pointer;
    margin-top: auto;
    margin-bottom: auto;
}

.overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--overlay-bg);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    z-index: 20;
    transition: opacity 0.3s ease-in-out;
}

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

h1 {
    font-size: 3rem;
    margin-bottom: 10px;
    color: var(--accent-color);
    text-transform: uppercase;
    letter-spacing: 2px;
}

p#message {
    font-size: 1.2rem;
    margin-bottom: 30px;
    max-width: 80%;
}

button#start-btn {
    background-color: var(--primary-color);
    color: var(--bg-color);
    border: none;
    padding: 15px 40px;
    font-size: 1.5rem;
    font-weight: bold;
    border-radius: 50px;
    cursor: pointer;
    box-shadow: 0 4px 6px rgba(0,0,0,0.2);
    transition: transform 0.2s, background-color 0.2s;
}

button#start-btn:hover {
    transform: scale(1.05);
    background-color: var(--secondary-color);
}

button:focus-visible {
    outline: 3px solid var(--accent-color);
    outline-offset: 2px;
}

@media (max-width: 480px) {
    h1 {
        font-size: 2rem;
    }

    .score-board {
        font-size: 1rem;
        flex-direction: column;
        gap: 5px;
    }

    button#start-btn {
        padding: 12px 30px;
        font-size: 1.2rem;
    }
}

.shake {
    animation: shake 0.5s;
}

@keyframes shake {
    0% { transform: translate(1px, 1px) rotate(0deg); }
    10% { transform: translate(-1px, -2px) rotate(-1deg); }
    20% { transform: translate(-3px, 0px) rotate(1deg); }
    30% { transform: translate(3px, 2px) rotate(0deg); }
    40% { transform: translate(1px, -1px) rotate(1deg); }
    50% { transform: translate(-1px, 2px) rotate(-1deg); }
    60% { transform: translate(-3px, 1px) rotate(0deg); }
    70% { transform: translate(3px, 1px) rotate(-1deg); }
    80% { transform: translate(-1px, -1px) rotate(1deg); }
    90% { transform: translate(1px, 2px) rotate(0deg); }
    100% { transform: translate(1px, -2px) rotate(-1deg); }
}