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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, 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;
    padding: 20px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
}

header .subtitle {
    font-size: 1.2rem;
    opacity: 0.9;
}

.controls {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 20px;
    padding: 15px;
    background: white;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.btn {
    padding: 10px 20px;
    border: none;
    border-radius: 5px;
    background: #667eea;
    color: white;
    font-size: 14px;
    cursor: pointer;
    transition: background 0.3s ease;
}

.btn:hover {
    background: #5a6fd6;
}

.search-box {
    display: flex;
    gap: 10px;
    flex-grow: 1;
}

#search-input {
    flex-grow: 1;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-size: 14px;
}

#search-input:focus {
    outline: none;
    border-color: #667eea;
}

.question-list {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.question-card {
    background: white;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    overflow: hidden;
    transition: box-shadow 0.3s ease;
}

.question-card:hover {
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.15);
}

.question-header {
    padding: 20px;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: #f8f9fa;
    border-bottom: 1px solid #eee;
    transition: background 0.3s ease;
}

.question-header:hover {
    background: #e9ecef;
}

.question-header h3 {
    font-size: 1.1rem;
    font-weight: 600;
    color: #333;
    flex-grow: 1;
    margin-right: 10px;
}

.question-header .icon {
    font-size: 1.5rem;
    color: #667eea;
    transition: transform 0.3s ease;
}

.question-card.active .question-header .icon {
    transform: rotate(180deg);
}

.question-content {
    padding: 0 20px;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease, padding 0.3s ease;
}

.question-card.active .question-content {
    padding: 20px;
    max-height: 1000px;
}

.answer-text {
    font-size: 1rem;
    line-height: 1.8;
    color: #555;
    white-space: pre-wrap;
}

footer {
    text-align: center;
    margin-top: 30px;
    padding: 20px;
    color: #666;
    font-size: 14px;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .container {
        padding: 10px;
    }

    header h1 {
        font-size: 2rem;
    }

    .controls {
        flex-direction: column;
    }

    .search-box {
        flex-direction: column;
    }

    .question-header {
        padding: 15px;
    }

    .question-content {
        padding: 0 15px;
    }

    .question-card.active .question-content {
        padding: 15px;
    }
}

/* 搜索高亮 */
.highlight {
    background-color: #fff3cd;
    padding: 2px 4px;
    border-radius: 3px;
}

/* 空状态 */
.no-results {
    text-align: center;
    padding: 40px;
    color: #666;
    font-size: 1.1rem;
}