/* ===== 回到顶部按钮 ===== */
.back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 50px;
    height: 50px;
    background: var(--gradient-2);
    border: none;
    border-radius: 50%;
    color: white;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: all 0.3s ease;
    z-index: 9998;
    box-shadow: 0 4px 20px rgba(0, 212, 255, 0.4);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 30px rgba(0, 212, 255, 0.6);
}

/* ===== 客户评价板块 ===== */
.testimonials {
    padding: 6rem 2rem;
    max-width: 1400px;
    margin: 0 auto;
}

.testimonials-slider {
    display: flex;
    gap: 2rem;
    overflow-x: auto;
    scroll-snap-type: x mandatory;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    padding-bottom: 1rem;
}

.testimonials-slider::-webkit-scrollbar {
    display: none;
}

.testimonial-card {
    flex: 0 0 400px;
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: 20px;
    padding: 2rem;
    scroll-snap-align: start;
    transition: all 0.4s ease;
}

.testimonial-card:hover {
    transform: translateY(-4px);
    border-color: rgba(0, 212, 255, 0.3);
}

.testimonial-content {
    font-size: 1.1rem;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 1.5rem;
    position: relative;
}

.testimonial-content::before {
    content: '"';
    font-size: 4rem;
    color: var(--accent-cyan);
    opacity: 0.3;
    position: absolute;
    top: -20px;
    left: -10px;
    font-family: serif;
}

.testimonial-author {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.author-avatar {
    width: 50px;
    height: 50px;
    background: var(--gradient-1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.2rem;
}

.author-info h4 {
    font-size: 1rem;
    margin-bottom: 0.25rem;
}

.author-info p {
    font-size: 0.875rem;
    color: var(--text-muted);
}

.testimonial-rating {
    color: #f7b731;
    font-size: 1.2rem;
    margin-top: 0.5rem;
}

/* ===== 合作伙伴Logo墙 ===== */
.partners {
    padding: 4rem 2rem;
    overflow: hidden;
}

.partners-track {
    display: flex;
    gap: 4rem;
    animation: scroll-partners 30s linear infinite;
}

.partners-track:hover {
    animation-play-state: paused;
}

@keyframes scroll-partners {
    0% { transform: translateX(0); }
    100% { transform: translateX(-50%); }
}

.partner-logo {
    flex: 0 0 auto;
    padding: 1rem 2rem;
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: 12px;
    color: var(--text-muted);
    font-family: var(--font-display);
    font-weight: 600;
    font-size: 1.2rem;
    opacity: 0.6;
    transition: all 0.3s ease;
}

.partner-logo:hover {
    opacity: 1;
    border-color: var(--accent-cyan);
    color: var(--text-primary);
}

/* ===== FAQ手风琴 ===== */
.faq {
    padding: 6rem 2rem;
    max-width: 900px;
    margin: 0 auto;
}

.faq-item {
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: 12px;
    margin-bottom: 1rem;
    overflow: hidden;
    transition: all 0.3s ease;
}

.faq-item:hover {
    border-color: rgba(0, 212, 255, 0.2);
}

.faq-question {
    padding: 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    font-weight: 600;
    transition: all 0.3s ease;
}

.faq-question:hover {
    color: var(--accent-cyan);
}

.faq-icon {
    width: 24px;
    height: 24px;
    transition: transform 0.3s ease;
}

.faq-item.active .faq-icon {
    transform: rotate(45deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease, padding 0.3s ease;
}

.faq-item.active .faq-answer {
    max-height: 500px;
    padding: 0 1.5rem 1.5rem;
}

.faq-answer p {
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ===== 导航栏滚动隐藏/显示 ===== */
.nav {
    transition: transform 0.3s ease, background 0.3s ease;
}

.nav.hidden {
    transform: translateY(-100%);
}

/* ===== 按钮波纹效果 ===== */
.btn {
    position: relative;
    overflow: hidden;
}

.btn::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    background: rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    transform: translate(-50%, -50%);
    transition: width 0.6s ease, height 0.6s ease;
}

.btn:active::after {
    width: 300px;
    height: 300px;
}

/* ===== 链接下划线动画 ===== */
.footer-links a {
    position: relative;
    display: inline-block;
}

.footer-links a::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 1px;
    background: var(--accent-cyan);
    transition: width 0.3s ease;
}

.footer-links a:hover::after {
    width: 100%;
}