body {
    margin: 0;
    padding: 0;
    background-color: #111;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    color: white;
    overflow: hidden;
}

#game-container {
    position: relative;
    box-shadow: 0 0 20px rgba(0, 255, 255, 0.2);
    border: 2px solid #333;
}

canvas {
    background-color: #000;
    display: block;
}

#ui-layer {
    position: absolute;
    top: 10px;
    left: 10px;
    right: 10px;
    display: flex;
    justify-content: space-between;
    pointer-events: none;
    font-size: 20px;
    font-weight: bold;
    text-shadow: 1px 1px 2px black;
}

.hidden {
    display: none !important;
}

#game-over-screen,
#victory-screen {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.85);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    z-index: 10;
}

h1 {
    font-size: 48px;
    margin-bottom: 20px;
    color: #ff4444;
}

#victory-screen h1 {
    color: #44ff44;
}

button {
    padding: 10px 20px;
    font-size: 24px;
    background-color: #444;
    color: white;
    border: none;
    cursor: pointer;
    border-radius: 5px;
    transition: background-color 0.2s;
}

button:hover {
    background-color: #666;
}

.shop-items {
    display: flex;
    flex-direction: column;
    gap: 10px;
    margin-bottom: 20px;
}

.shop-btn {
    font-size: 18px;
    padding: 8px 16px;
    width: 300px;
}

.next-level-btn {
    background-color: #44ff44;
    color: black;
    font-weight: bold;
}

.next-level-btn:hover {
    background-color: #66ff66;
}

#shop-screen {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.9);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    z-index: 20;
}

#level-transition-screen {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: black;
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 30;
    color: white;
}

#title-screen {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: #000;
    background-image: linear-gradient(rgba(0, 0, 0, 0.7), rgba(0, 0, 0, 0.7)), url('../assets/ship_background.png');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    z-index: 40;
}

.controls-info {
    text-align: center;
    margin-bottom: 40px;
    font-size: 24px;
    color: #fff;
    text-shadow: 0 0 10px rgba(0, 255, 255, 0.5);
    background-color: rgba(0, 0, 0, 0.5);
    padding: 20px;
    border-radius: 10px;
    border: 1px solid rgba(0, 255, 255, 0.3);
}

.difficulty-select {
    display: flex;
    gap: 20px;
}

.diff-btn {
    width: 150px;
    font-weight: bold;
}

#btn-easy {
    background-color: #44ff44;
    color: black;
}

#btn-normal {
    background-color: #4444ff;
}

#btn-hard {
    background-color: #ff4444;
}

#btn-easy:hover {
    background-color: #66ff66;
}

#btn-normal:hover {
    background-color: #6666ff;
}

#btn-hard:hover {
    background-color: #ff6666;
}