* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
}

body {
    background-color: #f8f9fa;
    color: #333;
    line-height: 1.6;
    padding: 20px;
    /* max-width: 1200px; */
    margin: 0 auto;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.container {
    background: white;
    border-radius: 16px;
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.08);
    padding: 40px;
    margin-top: 20px;
    will-change: transform;
}

.header {
    text-align: center;
    margin-bottom: 40px;
    padding-bottom: 20px;
    border-bottom: 2px solid #f0f0f0;
}

h1 {
    font-size: clamp(1.8rem, 4vw, 2.5rem);
    font-weight: 700;
    color: #1a1a1a;
    margin-bottom: 10px;
}

.header p {
    color: #666;
    font-size: clamp(1rem, 2vw, 1.1rem);
    max-width: 800px;
    margin: 0 auto;
}

.faq-container {
    max-width: 900px;
    margin: 0 auto;
}

.faq-item {
    border: 1px solid #eaeaea;
    border-radius: 12px;
    margin-bottom: 16px;
    overflow: hidden;
    background: #fff;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
    will-change: border-color, box-shadow;
}

.faq-item.active {
    border-color: #6366f1;
    box-shadow: 0 5px 15px rgba(99, 102, 241, 0.1);
}

.faq-question {
    padding: 22px 24px;
    font-size: 1.1rem;
    font-weight: 600;
    color: #1a1a1a;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: #fafafa;
    user-select: none;
    -webkit-tap-highlight-color: transparent;
}

.faq-question:hover {
    background-color: #f5f5f5;
}

.faq-question i {
    color: #6366f1;
    transition: transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
    font-size: 1.2rem;
    flex-shrink: 0;
    margin-left: 10px;
}

.faq-item.active .faq-question i {
    transform: rotate(180deg);
}

.faq-answer {
    height: 0;
    overflow: hidden;
    color: #555;
    line-height: 1.7;
    transform: translateZ(0);
    backface-visibility: hidden;
    perspective: 1000px;
}

.faq-item.active .faq-answer {
    height: auto;
}

.answer-content {
    padding: 24px;
    opacity: 0;
    transform: translateY(-10px);
    transition: opacity 0.3s ease, transform 0.3s ease;
}

.faq-item.active .answer-content {
    opacity: 1;
    transform: translateY(0);
}

.highlight-text {
    color: #6366f1;
    font-weight: 600;
}

.answer-section {
    margin-bottom: 20px;
}

.answer-section h4 {
    color: #333;
    margin-bottom: 8px;
    font-size: 1rem;
}

.answer-section p {
    margin-bottom: 12px;
    color: #555;
}

.bullet-list {
    padding-left: 20px;
    margin-top: 8px;
    list-style-type: none;
}

.bullet-list li {
    margin-bottom: 8px;
    color: #555;
    position: relative;
    padding-left: 20px;
}

.bullet-list li:before {
    content: "•";
    color: #6366f1;
    font-size: 1.2rem;
    position: absolute;
    left: 0;
    top: -1px;
}

.faq-tag {
    display: inline-block;
    background: #eef2ff;
    color: #6366f1;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-left: 10px;
    vertical-align: middle;
    flex-shrink: 0;
}

.faq-footer {
    text-align: center;
    margin-top: 40px;
    padding-top: 20px;
    border-top: 1px solid #eee;
    color: #777;
    font-size: 0.95rem;
}

.support-link {
    color: #6366f1;
    text-decoration: none;
    font-weight: 600;
    transition: color 0.2s;
}

.support-link:hover {
    color: #4f46e5;
    text-decoration: underline;
}


/* Performance optimizations */

@media (prefers-reduced-motion: reduce) {
    .faq-question i,
    .faq-item,
    .answer-content {
        transition: none !important;
    }
}


/* 优化移动端性能 */

@media (max-width: 768px) {
    body {
        padding: 10px;
    }
    .container {
        padding: 20px 15px;
        border-radius: 12px;
    }
    .faq-question {
        padding: 18px 20px;
        font-size: 1rem;
    }
    .answer-content {
        padding: 20px;
    }
    /* 在移动端减少阴影和动画以提升性能 */
    .faq-item {
        box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
    }
    .faq-item.active {
        box-shadow: 0 3px 10px rgba(99, 102, 241, 0.08);
    }
}


/* 性能优化类 */

.perf-optimized {
    contain: layout style paint;
    content-visibility: auto;
}


/* 针对WebKit的滚动优化 */

.faq-container {
    -webkit-overflow-scrolling: touch;
}