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

body {
    font-family: "Microsoft YaHei", sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f5f5f5;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
}

header {
    text-align: center;
    margin-bottom: 30px;
}

h1 {
    font-size: 2.5em;
    color: #2c3e50;
    margin-bottom: 10px;
}

h2 {
    font-size: 1.5em;
    color: #7f8c8d;
}

nav {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-bottom: 30px;
}

.nav-btn {
    padding: 10px 20px;
    font-size: 1.1em;
    border: none;
    border-radius: 5px;
    background-color: #3498db;
    color: white;
    cursor: pointer;
    transition: background-color 0.3s;
}

.nav-btn:hover {
    background-color: #2980b9;
}

.nav-btn.active {
    background-color: #2c3e50;
}

.section {
    display: none;
    background-color: white;
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.section.active {
    display: block;
}

.audio-container {
    text-align: center;
}

.poem-text {
    font-size: 1.4em;
    line-height: 2;
    margin: 20px 0;
    color: #2c3e50;
}

.recording-container {
    text-align: center;
}

.btn {
    padding: 10px 20px;
    font-size: 1.1em;
    border: none;
    border-radius: 5px;
    background-color: #3498db;
    color: white;
    cursor: pointer;
    margin: 10px;
    transition: background-color 0.3s;
}

.btn:hover {
    background-color: #2980b9;
}

.btn:disabled {
    background-color: #bdc3c7;
    cursor: not-allowed;
}

.audio-playback, .standard-audio {
    margin: 20px 0;
}

.practice-container {
    max-width: 600px;
    margin: 0 auto;
}

.fill-in-line {
    display: flex;
    align-items: center;
    margin: 15px 0;
}

.fill-in-blank {
    flex: 1;
    padding: 10px;
    font-size: 1.1em;
    border: 2px solid #bdc3c7;
    border-radius: 5px;
    margin-right: 10px;
}

.voice-btn {
    padding: 8px 15px;
    font-size: 1em;
    border: none;
    border-radius: 5px;
    background-color: #3498db;
    color: white;
    cursor: pointer;
    margin-right: 10px;
    transition: background-color 0.3s;
}

.voice-btn:hover {
    background-color: #2980b9;
}

.voice-btn.recording {
    background-color: #e74c3c;
    animation: pulse 1.5s infinite;
}

.voice-btn.stop-btn {
    background-color: #e74c3c;
}

.voice-btn.stop-btn:hover {
    background-color: #c0392b;
}

@keyframes pulse {
    0% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
    100% {
        transform: scale(1);
    }
}

.line-number {
    font-size: 1.2em;
    color: #7f8c8d;
    width: 30px;
    text-align: center;
}

.result {
    margin-top: 20px;
    padding: 15px;
    border-radius: 5px;
    text-align: center;
}

.result.correct {
    background-color: #2ecc71;
    color: white;
}

.result.incorrect {
    background-color: #e74c3c;
    color: white;
}

audio {
    width: 100%;
    max-width: 400px;
    margin: 10px 0;
}