body {
    margin: 0;
    background-color: #020202;
    color: #00ffcc;
    font-family: 'Courier New', Courier, monospace;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    overflow: hidden;
}

#game-container {
    position: relative;
    box-shadow: 0 0 50px rgba(0, 255, 204, 0.15);
}

#start-screen {
    position: absolute;
    top: 0;
    left: 0;
    width: 800px;
    height: 720px; /* 包含遊戲區與下方 HUD 區 */
    background: rgba(2, 5, 5, 0.95);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 100;
    color: #00ffcc;
    font-family: 'monospace', '微軟正黑體';
}

.start-content {
    text-align: center;
    border: 2px solid #00ffcc;
    padding: 40px;
    background: rgba(0, 20, 20, 0.8);
    box-shadow: 0 0 20px rgba(0, 255, 204, 0.3);
}

.slogan {
    font-size: 48px;
    letter-spacing: 15px;
    margin-bottom: 5px;
    text-shadow: 0 0 10px #00ffcc;
}

.slogan-en {
    font-size: 20px;
    letter-spacing: 8px;
    color: #66ff66;
    margin-bottom: 30px;
}

.tutorial-box {
    background: rgba(0, 0, 0, 0.5);
    padding: 20px;
    border: 1px solid #336666;
    text-align: left;
    margin-bottom: 30px;
}

.tut-title {
    color: #ffff00;
    font-weight: bold;
    margin-bottom: 10px;
}

.tutorial-box ul {
    list-style: none;
    padding: 0;
}

.tutorial-box li {
    margin: 8px 0;
    font-size: 16px;
}

.tutorial-box span {
    color: #66ff66;
}

.mission-text {
    color: #e6ffff;
    text-align: center;
    margin-top: 15px;
}

#start-btn {
    background: #00ffcc;
    color: #000;
    border: none;
    padding: 12px 30px;
    font-size: 18px;
    font-weight: bold;
    cursor: pointer;
    transition: 0.3s;
}

#start-btn:hover {
    background: #ffffff;
    box-shadow: 0 0 15px #ffffff;
    transform: scale(1.05);
}

#ui-top {
    position: absolute;
    top: -45px;
    width: 100%;
    display: flex;
    justify-content: space-between;
    font-weight: bold;
    letter-spacing: 1px;
}

.stat-box {
    background: rgba(0, 255, 204, 0.1);
    padding: 5px 15px;
    border: 1px solid #00ffcc;
}

canvas {
    background: #050505;
    border: 2px solid #1a1a1a;
    display: block;
    image-rendering: pixelated; /* 維持像素清晰度 */
}

#overlay {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: rgba(0, 0, 0, 0.95);
    border: 2px solid #ff3366;
    padding: 30px;
    text-align: center;
    display: none;
    z-index: 100;
}

button {
    background: transparent;
    border: 1px solid #00ffcc;
    color: #00ffcc;
    padding: 10px 25px;
    cursor: pointer;
    font-family: inherit;
    transition: 0.2s;
}

button:hover {
    background: #00ffcc;
    color: #000;
}

#hudCanvas {
    box-shadow: 0 -5px 15px rgba(0, 255, 204, 0.5);
    margin-top: 5px;
    border-radius: 0 0 10px 10px;
}