:root {
    --primary-red: #ef443b;
    --text-main: #1f2937;
}
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Noto Sans', 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
    font-style: normal;
    font-weight: 400;
    font-display: swap;
}
body {
    color: var(--text-main);
    background: #ffffff;
    line-height: 1.5;
    overflow-x: hidden;
}

/* 导航栏 */
nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 8%;
    height: 80px;
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    background: radial-gradient(circle at 10% 20%, rgba(239, 68, 68, 0.03) 0%, rgba(255, 255, 255, 1) 50%);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid #f3f4f6;
}
.nav-left { display: flex; align-items: center; }
.logo { margin-right: 40px; }
.logo img { height: 30px; width: 158px; }
.nav-links { display: flex; list-style: none; }
.nav-links li {
    display: flex; align-items: center; gap: 4px; position: relative;
    margin: 0 15px; border-bottom: 3px solid transparent;
}
.nav-links li:hover { border-bottom: 3px solid #FFD5D6; }
.nav-links a {
    text-decoration: none; color: var(--text-main); font-size: 15px; font-weight: 500;
    display: flex; align-items: center;
}
.nav-links-svg { width: 12px; height: 12px; }
.nav-right { display: flex; align-items: center; }
.btn-link {
    text-decoration: none; color: var(--primary-red); padding: 10px 24px;
    border: 2px solid var(--primary-red); border-radius: 6px; font-weight: 600; font-size: 14px;
    margin-left: 12px; transition: 0.3s;
}
.btn-link:hover { background: var(--primary-red); color: #fff; }
.btn-outline {
    text-decoration: none; color: #fff; background: var(--primary-red); padding: 11px 24px;
    border-radius: 6px; font-weight: 600; font-size: 14px; transition: 0.3s;
}
.btn-outline:hover { background: #d93833; }

/* FAQ 头部 */
.faq-hero {
    padding: 160px 8% 60px;
    background: radial-gradient(circle at 50% 0%, rgba(239, 68, 68, 0.04) 0%, rgba(255, 255, 255, 1) 70%);
    text-align: center;
}
.faq-hero h1 {
    font-size: 3.5rem;
    font-weight: 700;
    color: #1f2937;
    margin-bottom: 15px;
}
.faq-hero h1 span {
    background: -webkit-linear-gradient(45deg, #ef443b, #EE8D3B);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}
.faq-hero p {
    font-size: 1.2rem;
    color: #4b5563;
    font-weight: 400;
    max-width: 700px;
    margin: 0 auto;
}

/* FAQ 容器 */
.faq-container {
    max-width: 900px;
    margin: 0 auto 80px;
    padding: 0 4%;
}

.faq-group {
    margin-bottom: 40px;
}
.faq-group-title {
    font-size: 1.6rem;
    font-weight: 700;
    color: var(--primary-red);
    margin-bottom: 20px;
    padding-left: 10px;
    border-left: 4px solid var(--primary-red);
}
.faq-item {
    background: #ffffff;
    border: 1px solid #e5e7eb;
    border-radius: 12px;
    margin-bottom: 16px;
    overflow: hidden;
    transition: border-color 0.3s, box-shadow 0.3s;
}
.faq-item:hover {
    border-color: #ffbabb;
    box-shadow: 0 10px 25px rgba(239, 68, 68, 0.03);
}

.faq-checkbox {
    display: none;
}
.faq-trigger {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 24px 30px;
    cursor: pointer;
    user-select: none;
}
.faq-trigger h3 {
    font-size: 1.15rem;
    color: #1f2937;
    font-weight: 700;
    padding-right: 20px;
}
.faq-icon {
    width: 16px;
    height: 16px;
    position: relative;
    transition: transform 0.3s ease;
    flex-shrink: 0;
}
.faq-icon::before, .faq-icon::after {
    content: '';
    position: absolute;
    background-color: #9ca3af;
    transition: background-color 0.3s;
}
.faq-icon::before { top: 7px; left: 0; width: 16px; height: 2px; }
.faq-icon::after { top: 0; left: 7px; width: 2px; height: 16px; }

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    background: #fafafa;
}
.faq-answer-content {
    padding: 0 30px 24px;
}
.faq-answer-content p {
    font-size: 1rem;
    color: #4b5563;
    line-height: 1.8;
    font-weight: 400;
    margin-bottom: 12px;
}
.faq-answer-content p strong {
    font-weight: 700;
    color: #000;
}

.faq-media-box {
    margin: 20px 0 10px;
    background: #ffffff;
    border: 1px dashed #d1d5db;
    border-radius: 8px;
    padding: 15px;
    text-align: center;
}
.faq-media-box img {
    max-width: 100%;
    height: auto;
    border-radius: 4px;
    display: block;
    margin: 0 auto;
}
.faq-media-caption {
    font-size: 0.8rem;
    color: #9ca3af;
    margin-top: 8px;
    font-weight: 500;
}

/* 手风琴展开状态 */
.faq-checkbox:checked ~ .faq-answer {
    max-height: 1500px; /* 足够容纳长文本 */
    border-top: 1px solid #f3f4f6;
}
.faq-checkbox:checked ~ .faq-trigger .faq-icon {
    transform: rotate(45deg);
}
.faq-checkbox:checked ~ .faq-trigger .faq-icon::before,
.faq-checkbox:checked ~ .faq-trigger .faq-icon::after {
    background-color: var(--primary-red);
}
.faq-checkbox:checked ~ .faq-trigger h3 {
    color: var(--primary-red);
}

/* 创意版块：智能诊断 */
.troubleshoot-promo {
    max-width: 900px;
    margin: 0 auto 80px;
    padding: 0 4%;
    display: flex;
    align-items: center;
    gap: 40px;
    background: linear-gradient(135deg, #fff5f5 0%, #fff 100%);
    border-radius: 24px;
    border: 1px solid #fed7d7;
    padding: 50px 40px;
}
.promo-content {
    flex: 1;
}
.promo-content h2 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 15px;
    color: #1f2937;
}
.promo-content h2 span {
    color: var(--primary-red);
}
.promo-content p {
    font-size: 1.05rem;
    color: #4b5563;
    margin-bottom: 25px;
    line-height: 1.7;
}
.promo-actions {
    display: flex;
    gap: 15px;
    margin-bottom: 20px;
}
.btn-promo-primary {
    background: var(--primary-red);
    color: #fff;
    padding: 12px 28px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 700;
    transition: 0.3s;
}
.btn-promo-primary:hover {
    background: #d93833;
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(239,68,68,0.3);
}
.btn-promo-outline {
    border: 2px solid var(--primary-red);
    color: var(--primary-red);
    padding: 12px 28px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 700;
    transition: 0.3s;
}
.btn-promo-outline:hover {
    background: var(--primary-red);
    color: #fff;
}
.promo-tip {
    font-size: 0.9rem;
    color: #9ca3af;
}
.promo-tip a {
    color: var(--primary-red);
    text-decoration: none;
    font-weight: 600;
}
.promo-visual {
    flex: 0 0 280px;
    display: flex;
    align-items: center;
    justify-content: center;
}
.promo-visual img {
    width: 100%;
    height: auto;
    background: #fff;
    box-shadow: 0 10px 25px rgba(0,0,0,0.05);
}

/* 页脚 */
footer {
    background: #111111;
    color: #ffffff;
    padding: 80px 8% 40px;
    font-family: 'Noto Sans', sans-serif;
}
.footer-container {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr 1fr 1fr;
    gap: 40px;
}
.footer-logo-section img { height: 35px; margin-bottom: 20px; }
.footer-logo-section p { color: #999; font-size: 14px; margin-bottom: 10px; }
.footer-column h3 {
    color: var(--primary-red); font-size: 1.2rem; font-weight: 700; margin-bottom: 25px;
    position: relative; padding-bottom: 15px;
}
.footer-column h3::after {
    content: ''; position: absolute; bottom: 0; left: 0; width: 100%; height: 1px; background: #333;
}
.footer-column ul { list-style: none; }
.footer-column ul li { margin-bottom: 12px; }
.footer-column ul li a { color: #cccccc; text-decoration: none; font-size: 14px; transition: 0.3s; }
.footer-column ul li a:hover { color: var(--primary-red); }
.footer-bottom {
    margin-top: 60px; padding-top: 30px; border-top: 1px solid #222;
    display: flex; justify-content: space-between; align-items: center; font-size: 12px; color: #666;
}
.footer-socials { display: flex; gap: 20px; }
.footer-socials a { color: #666; text-decoration: none; transition: 0.3s; }
.footer-socials a:hover { color: #fff; }

/* 响应式 */
@media (max-width: 1024px) {
    .footer-container { grid-template-columns: 1fr 1fr; }
    .footer-logo-section { grid-column: span 2; text-align: center; margin-bottom: 40px; }
    .troubleshoot-promo { flex-direction: column; text-align: center; }
    .promo-actions { justify-content: center; }
    .promo-visual { flex: 0 0 auto; width: 100%; }
}
@media (max-width: 768px) {
    .faq-hero h1 { font-size: 2.4rem; }
    .faq-trigger { padding: 20px; }
    .faq-answer-content { padding: 0 20px 20px; }
    .troubleshoot-promo { padding: 30px 20px; }
}