/* ========== 全局变量与重置 ========== */
:root {
    --primary-red: #ef443b;
    --primary-dark: #d93833;
    --text-main: #1f2937;
    --text-secondary: #4b5563;
    --bg-light: #f9fafb;
    --border-light: #f0f0f0;
    --shadow-sm: 0 10px 25px rgba(0, 0, 0, 0.02);
    --shadow-md: 0 15px 35px rgba(239, 68, 68, 0.08);
    --shadow-lg: 0 25px 50px rgba(0, 0, 0, 0.05);
    --radius-sm: 8px;
    --radius-md: 16px;
    --radius-lg: 24px;
    --radius-xl: 20px;
}

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

body {
    font-family: 'Noto Sans', 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
    color: var(--text-main);
    background: #ffffff;
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

/* ========== 导航栏 (与首页统一) ========== */
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: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid #f3f4f6;
}

.nav-left {
    display: flex;
    align-items: center;
    gap: 40px;
}

.logo img {
    height: 30px;
    width: 158px;
    display: block;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 8px;
}

.nav-links li {
    display: flex;
    align-items: center;
    gap: 4px;
    padding: 8px 12px;
    border-radius: 6px;
    transition: background 0.2s;
    border-bottom: 3px solid transparent;
}

.nav-links li:hover {
    background: rgba(239, 68, 68, 0.04);
    border-bottom-color: #FFD5D6;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-main);
    font-size: 15px;
    font-weight: 500;
    display: flex;
    align-items: center;
    white-space: nowrap;
}

.nav-links-svg {
    width: 12px;
    height: 12px;
    opacity: 0.7;
}

.nav-right {
    display: flex;
    align-items: center;
    gap: 12px;
}

.btn-link {
    text-decoration: none;
    color: var(--primary-red);
    padding: 10px 24px;
    border: 2px solid var(--primary-red);
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: 14px;
    transition: all 0.3s ease;
    white-space: nowrap;
}

.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: var(--radius-sm);
    font-weight: 600;
    font-size: 14px;
    transition: all 0.3s ease;
    white-space: nowrap;
}

.btn-outline:hover {
    background: var(--primary-dark);
}

/* ========== 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: var(--text-main);
    margin-bottom: 15px;
}

.faq-hero h1 span {
    background: linear-gradient(135deg, #ef443b, #EE8D3B);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.faq-hero p {
    font-size: 1.2rem;
    color: var(--text-secondary);
    font-weight: 400;
    max-width: 700px;
    margin: 0 auto;
    line-height: 1.7;
}

/* ========== 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: 15px;
    border-left: 4px solid var(--primary-red);
}

/* 手风琴卡片 */
.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: var(--text-main);
    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 0.4s 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: var(--text-secondary);
    line-height: 1.8;
    font-weight: 400;
    margin-bottom: 12px;
}

.faq-answer-content p strong {
    font-weight: 700;
    color: #000;
}

/* 手风琴展开状态 */
.faq-checkbox:checked~.faq-answer {
    max-height: 2000px;
    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);
}

/* ========== 版本对比创意卡片 ========== */
.version-compare-card {
    background: #fff;
    border: 1px solid #f0f0f0;
    border-radius: var(--radius-lg);
    padding: 40px;
    margin: 50px 0;
    box-shadow: var(--shadow-sm);
}

.version-compare-card h3 {
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 25px;
    text-align: center;
}

.compare-grid {
    display: flex;
    flex-direction: column;
    gap: 0;
    border: 1px solid #e5e7eb;
    border-radius: 12px;
    overflow: hidden;
}

.compare-col {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr 1fr;
    padding: 14px 20px;
    background: #fff;
    border-bottom: 1px solid #f0f0f0;
    align-items: center;
}

.compare-col:last-child {
    border-bottom: none;
}

.compare-header {
    background: #f9fafb;
    font-weight: 700;
    color: var(--text-main);
    font-size: 0.95rem;
}

.compare-col span {
    font-size: 0.9rem;
    color: var(--text-secondary);
    text-align: center;
}

.compare-col span:first-child {
    text-align: left;
    font-weight: 600;
    color: var(--text-main);
}

.compare-note {
    font-size: 0.85rem;
    color: #9ca3af;
    margin-top: 16px;
    text-align: center;
}

/* ========== 底部行动号召 ========== */
.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: var(--radius-lg);
    border: 1px solid #fed7d7;
    padding: 50px 40px;
}

.promo-content {
    flex: 1;
}

.promo-content h2 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 15px;
    color: var(--text-main);
}

.promo-content h2 span {
    color: var(--primary-red);
}

.promo-content p {
    font-size: 1.05rem;
    color: var(--text-secondary);
    margin-bottom: 25px;
    line-height: 1.7;
}

.promo-actions {
    display: flex;
    gap: 15px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.btn-promo-primary {
    background: var(--primary-red);
    color: #fff;
    padding: 12px 28px;
    border-radius: var(--radius-sm);
    text-decoration: none;
    font-weight: 700;
    transition: all 0.3s ease;
}

.btn-promo-primary:hover {
    background: var(--primary-dark);
    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: var(--radius-sm);
    text-decoration: none;
    font-weight: 700;
    transition: all 0.3s ease;
}

.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 (与首页统一) ========== */
footer {
    background: #111111;
    color: #ffffff;
    padding: 80px 8% 40px;
}

.footer-container {
    display: grid;
    grid-template-columns: 1.8fr 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: 8px;
}

.footer-domain {
    color: var(--primary-red) !important;
    font-weight: 600;
}

.footer-column h3 {
    color: var(--primary-red);
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 24px;
    position: relative;
    padding-bottom: 12px;
}

.footer-column h3::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 30px;
    height: 2px;
    background: var(--primary-red);
    border-radius: 2px;
}

.footer-column ul {
    list-style: none;
}

.footer-column ul li {
    margin-bottom: 10px;
}

.footer-column ul li a {
    color: #cccccc;
    text-decoration: none;
    font-size: 14px;
    transition: color 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: 13px;
    color: #888;
    flex-wrap: wrap;
    gap: 16px;
}

.footer-socials {
    display: flex;
    gap: 20px;
}

.footer-socials a {
    color: #888;
    text-decoration: none;
    transition: color 0.3s;
}

.footer-socials a:hover {
    color: #fff;
}

/* ========== 响应式设计 ========== */
@media (max-width: 1024px) {
    .footer-container {
        grid-template-columns: 1fr 1fr;
        gap: 40px;
    }
    .footer-logo-section {
        grid-column: span 2;
        text-align: center;
    }
    .troubleshoot-promo {
        flex-direction: column;
        text-align: center;
        padding: 40px 30px;
    }
    .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;
    }
    .compare-col {
        grid-template-columns: 1.5fr 1fr 1fr 1fr;
        padding: 10px 15px;
    }
    .compare-col span {
        font-size: 0.8rem;
    }
    .version-compare-card {
        padding: 25px 15px;
    }
}