:root {
    --bg-color: #87ceeb;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Roboto', sans-serif;
}

body {
    background-color: #111;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

.game-container {
    position: relative;
    width: 400px;
    height: 600px;
    overflow: hidden;
    background-color: var(--bg-color);
    border: 4px solid #333;
    border-radius: 10px;
}

#flappyCanvas {
    display: block;
}

#scoreDisplay {
    position: absolute;
    top: 20px;
    left: 0;
    width: 100%;
    text-align: center;
    font-size: 3rem;
    font-weight: 900;
    color: white;
    text-shadow: 2px 2px 0 #000;
    z-index: 10;
}

#gameOverScreen {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.7);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    z-index: 20;
    color: white;
}

#gameOverScreen h2 {
    font-size: 3rem;
    margin-bottom: 20px;
    text-shadow: 2px 2px 0 #000;
}

button {
    background: #ffeb3b;
    color: #000;
    border: none;
    padding: 10px 20px;
    font-size: 1.2rem;
    font-weight: bold;
    border-radius: 5px;
    cursor: pointer;
    text-transform: uppercase;
}

button:hover {
    background: #ffd600;
}

.back-btn {
    color: #fff;
    margin-top: 20px;
    font-weight: bold;
}