/* 全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: Arial, sans-serif;
    background-color: #f5f5f5;
    color: #333;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    overflow: hidden;
}

/* 屏幕容器 */
.screen {
    background-color: white;
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    padding: 40px;
    max-width: 900px;
    width: 90%;
    text-align: center;
}

.screen.hidden {
    display: none;
}

/* 标题样式 */
h1 {
    color: #2E7D32;
    margin-bottom: 10px;
    font-size: 32px;
}

h2 {
    color: #4CAF50;
    margin-bottom: 20px;
    font-size: 28px;
}

h3 {
    color: #555;
    margin-bottom: 15px;
    font-size: 20px;
}

p {
    margin-bottom: 10px;
    font-size: 16px;
    color: #666;
}

/* 按钮样式 */
button {
    padding: 12px 24px;
    font-size: 16px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s, transform 0.1s;
    margin: 5px;
}

button:hover {
    transform: scale(1.05);
}

button:active {
    transform: scale(0.95);
}

.main-btn {
    background-color: #4CAF50;
    color: white;
    font-size: 18px;
    padding: 15px 30px;
    margin-top: 20px;
}

.main-btn:hover {
    background-color: #45a049;
}

.difficulty-btn {
    background-color: #2196F3;
    color: white;
    padding: 10px 20px;
    margin: 5px;
    min-width: 120px;
}

.difficulty-btn:hover {
    background-color: #0b7dda;
}

.difficulty-btn.selected {
    background-color: #FF5722;
}

/* C1难度按钮特殊样式 */
.difficulty-btn[data-level="C1"] {
    background-color: #9C27B0;
}

.difficulty-btn[data-level="C1"].selected {
    background-color: #7B1FA2;
}

/* 难度选择器 */
.difficulty-selector {
    margin: 30px 0;
}

.difficulty-selector h3 {
    margin-bottom: 15px;
}

/* 操作说明 */
.instructions {
    margin: 30px 0;
    text-align: left;
    background-color: #f9f9f9;
    padding: 20px;
    border-radius: 5px;
}

.instructions ul {
    list-style-position: inside;
    margin-left: 20px;
}

.instructions li {
    margin-bottom: 8px;
    color: #555;
}

/* 游戏界面 */
#game-screen {
    padding: 20px;
}

.game-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    padding: 15px;
    background-color: #f9f9f9;
    border-radius: 5px;
}

.header-info {
    display: flex;
    gap: 30px;
    font-size: 18px;
    font-weight: bold;
}

.header-controls {
    display: flex;
    gap: 10px;
}

#pause-btn {
    background-color: #FF9800;
    color: white;
}

#pause-btn:hover {
    background-color: #e68900;
}

#exit-btn {
    background-color: #f44336;
    color: white;
}

#exit-btn:hover {
    background-color: #da190b;
}

/* 游戏画布 */
#game-canvas {
    display: block;
    margin: 0 auto;
    border: 3px solid #4CAF50;
    border-radius: 5px;
    background-color: white;
}

/* 游戏底部信息 */
.game-footer {
    margin-top: 20px;
    padding: 15px;
    background-color: #f9f9f9;
    border-radius: 5px;
}

.target-sentence,
.progress-sentence {
    margin-bottom: 10px;
    font-size: 18px;
    font-weight: bold;
}

.target-sentence {
    color: #333;
}

.target-sentence.hidden {
    display: none;
}

.progress-sentence {
    color: #2196F3;
}

/* 关卡完成界面 */
#level-complete-screen h2 {
    color: #4CAF50;
    font-size: 36px;
}

#completed-sentence-display {
    color: #333;
    font-size: 24px;
    margin: 20px 0;
    padding: 15px;
    background-color: #e8f5e9;
    border-radius: 5px;
}

.score-info {
    margin: 30px 0;
    font-size: 20px;
}

.score-info p {
    margin: 10px 0;
    font-size: 18px;
}

/* 游戏结束界面 */
#game-over-screen h2 {
    color: #f44336;
    font-size: 36px;
}

.final-info {
    margin: 30px 0;
    font-size: 20px;
}

.final-info p {
    margin: 10px 0;
    font-size: 18px;
}

.game-over-buttons {
    margin-top: 20px;
}

#restart-btn {
    background-color: #4CAF50;
}

#menu-btn {
    background-color: #2196F3;
}

/* 响应式设计 */
@media (max-width: 900px) {
    .screen {
        padding: 20px;
        width: 95%;
    }

    h1 {
        font-size: 24px;
    }

    h2 {
        font-size: 20px;
    }

    #game-canvas {
        width: 100%;
        height: auto;
    }

    .header-info {
        font-size: 14px;
        gap: 15px;
    }

    .header-controls button {
        padding: 8px 16px;
        font-size: 14px;
    }
}

/* 动画效果 */
@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

.screen {
    animation: fadeIn 0.3s ease-in;
}