/* ===== 全局重置 ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
body {
    background-color: #f8fafc;
    color: #0b1a2e;
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    line-height: 1.6;
    padding-bottom: 80px;
}
a {
    color: #3276ff;
    text-decoration: none;
}
a:hover {
    text-decoration: underline;
}
img {
    max-width: 100%;
    height: auto;
    display: block;
}
.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ===== 顶部导航 ===== */
.site-header {
    background: #ffffff;
    border-bottom: 1px solid #e9edf2;
    position: sticky;
    top: 0;
    z-index: 30;
    box-shadow: 0 2px 8px rgba(0,0,0,0.02);
}
.navbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    padding: 16px 0 14px;
}

/* ===== Logo 区域 (图片+文字) ===== */
.logo-area {
    display: flex;
    align-items: center;
    gap: 10px;
}
.logo-link {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    color: inherit;
}
.logo-link:hover {
    text-decoration: none;
}
.logo-img {
    width: 32px;
    height: 32px;
    display: block;
    flex-shrink: 0;
}
.logo-text {
    font-weight: 700;
    font-size: 22px;
    letter-spacing: -0.3px;
    color: #0b1a2e;
}
.logo-text span {
    color: #3276ff;
}

/* ===== 右侧操作按钮 ===== */
.nav-right {
    display: flex;
    align-items: center;
    gap: 12px;
}
.btn-download {
    background-color: #3276ff;
    color: #fff;
    border: none;
    padding: 10px 22px;
    border-radius: 40px;
    font-weight: 600;
    font-size: 0.95rem;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    transition: background 0.2s, transform 0.1s;
    box-shadow: 0 4px 10px rgba(50, 118, 255, 0.25);
    text-decoration: none;
    white-space: nowrap;
}
.btn-download i {
    font-size: 1.1rem;
}
.btn-download:hover {
    background-color: #1a5fd9;
    transform: scale(1.02);
    text-decoration: none;
}
.btn-download:active {
    transform: scale(0.97);
}
.nav-mobile-download {
    display: none;
}
.btn-download-mobile-icon {
    background: #3276ff;
    color: #fff;
    border: none;
    width: 44px;
    height: 44px;
    border-radius: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    box-shadow: 0 4px 12px rgba(50, 118, 255, 0.3);
    cursor: pointer;
    transition: background 0.2s;
    text-decoration: none;
}
.btn-download-mobile-icon:hover {
    background: #1a5fd9;
    text-decoration: none;
}

/* ===== 主体布局：左侧分类导航 + 右侧内容 ===== */
.main-layout {
    display: flex;
    gap: 28px;
    margin-top: 24px;
    align-items: flex-start;
}

/* ===== 左侧导航 (竖排 Tab) ===== */
.category-tabs {
    flex: 0 0 110px;
    min-width: 90px;
    background: #ffffff;
    border-radius: 20px;
    border: 1px solid #eef2f6;
    padding: 12px 0;
    box-shadow: 0 4px 12px rgba(0,0,0,0.02);
    position: sticky;
    top: 90px;
    align-self: flex-start;
}
.category-tabs .tab-item {
    display: block;
    padding: 10px 16px;
    font-size: 0.9rem;
    font-weight: 500;
    color: #475569;
    border-left: 3px solid transparent;
    transition: background 0.15s, color 0.15s, border-color 0.15s;
    cursor: pointer;
    text-decoration: none;
    white-space: nowrap;
}
.category-tabs .tab-item:hover {
    background: #f1f5f9;
    color: #0b1a2e;
    text-decoration: none;
}
.category-tabs .tab-item.active {
    color: #3276ff;
    border-left-color: #3276ff;
    background: #eff6ff;
    font-weight: 600;
}

/* ===== 右侧内容区 ===== */
.content-main {
    flex: 1;
    min-width: 0;
}

/* ===== 下载区域 ===== */
.hero-download {
    background: linear-gradient(145deg, #ffffff, #f8fafc);
    border-radius: 28px;
    padding: 24px 28px;
    margin-bottom: 32px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 20px;
    border: 1px solid #eef2f6;
    box-shadow: 0 6px 18px rgba(0,0,0,0.02);
}
.hero-download-left {
    display: flex;
    align-items: center;
    gap: 24px;
    flex-wrap: wrap;
}
.hero-download-text {
    font-size: 1.1rem;
    font-weight: 600;
    color: #0b1a2e;
}
.hero-download-text small {
    font-weight: 400;
    font-size: 0.9rem;
    color: #475569;
    display: block;
    margin-top: 2px;
}
.hero-qrcode {
    display: flex;
    align-items: center;
    gap: 12px;
    background: #ffffff;
    padding: 4px 14px 4px 4px;
    border-radius: 60px;
    border: 1px solid #e9edf2;
}
.hero-qrcode img {
    width: 54px;
    height: 54px;
    border-radius: 10px;
    background: #f1f5f9;
    object-fit: contain;
}
.hero-qrcode .qr-label {
    font-size: 0.7rem;
    color: #475569;
    font-weight: 500;
}
.hero-download-right .btn-download {
    padding: 12px 36px;
    font-size: 1rem;
    box-shadow: 0 8px 24px rgba(50, 118, 255, 0.25);
}

/* ===== 通用区块标题 ===== */
.section-header {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    margin-bottom: 18px;
    flex-wrap: wrap;
}
.section-header h2 {
    font-size: 1.6rem;
    font-weight: 700;
    letter-spacing: -0.3px;
    color: #0b1a2e;
}
.section-header .more-link {
    color: #3276ff;
    font-weight: 500;
    font-size: 0.9rem;
    display: inline-flex;
    align-items: center;
    gap: 4px;
}

/* ===== 热门内容 (首页) ===== */
.hot-section {
    margin: 0 0 40px;
}
.hot-list {
    display: flex;
    flex-direction: column;
    gap: 28px;
}
.hot-card {
    background: #ffffff;
    border-radius: 20px;
    overflow: hidden;
    border: 1px solid #f1f4f9;
    box-shadow: 0 4px 14px rgba(0,0,0,0.02);
    transition: transform 0.15s, box-shadow 0.2s;
}
.hot-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 12px 28px rgba(0,0,0,0.04);
    border-color: #dce2ec;
}
.hot-card-content {
    padding: 16px 22px 10px 22px;
}
.hot-card-title {
    font-weight: 600;
    font-size: 1.2rem;
    margin-bottom: 4px;
    color: #0b1a2e;
}
.hot-card-title a {
    color: inherit;
    text-decoration: none;
}
.hot-card-title a:hover {
    color: #3276ff;
    text-decoration: underline;
}
.hot-card-meta {
    display: flex;
    gap: 18px;
    font-size: 0.8rem;
    color: #64748b;
    margin-top: 4px;
}
.hot-card-meta i {
    margin-right: 4px;
    color: #94a3b8;
}
.hot-card-image {
    width: 100%;
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    min-height: 180px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: #e2e8f0;
    background-image: linear-gradient(145deg, #e9edf2, #dce2ea);
}

/* ===== 今日更新 / 本周热门 (共用卡片样式) ===== */
.update-section {
    margin: 0 0 20px;
}
.update-list {
    display: flex;
    flex-direction: column;
    gap: 28px;
}
.update-card {
    background: #ffffff;
    border-radius: 20px;
    overflow: hidden;
    border: 1px solid #f1f4f9;
    box-shadow: 0 4px 14px rgba(0,0,0,0.02);
    transition: transform 0.15s, box-shadow 0.2s;
}
.update-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 12px 28px rgba(0,0,0,0.04);
    border-color: #dce2ec;
}
.update-card-content {
    padding: 16px 22px 10px 22px;
}
.update-card-title {
    font-weight: 600;
    font-size: 1.2rem;
    margin-bottom: 4px;
    color: #0b1a2e;
}
.update-card-title a {
    color: inherit;
    text-decoration: none;
}
.update-card-title a:hover {
    color: #3276ff;
    text-decoration: underline;
}
.update-card-meta {
    display: flex;
    gap: 18px;
    font-size: 0.8rem;
    color: #64748b;
    margin-top: 4px;
    flex-wrap: wrap;
}
.update-card-meta i {
    margin-right: 4px;
    color: #94a3b8;
}
.update-card-meta .tag {
    background: #eff6ff;
    color: #3276ff;
    padding: 0 10px;
    border-radius: 12px;
    font-size: 0.7rem;
    font-weight: 500;
}
.update-card-image {
    width: 100%;
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    min-height: 180px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: #e2e8f0;
    background-image: linear-gradient(145deg, #e9edf2, #dce2ea);
}
/* 更新时间戳 (今日更新专用) */
.update-time {
    font-size: 0.75rem;
    color: #94a3b8;
    margin-left: 8px;
}
.update-time i {
    margin-right: 2px;
}

/* ===== 人气作者 ===== */
.authors-section {
    margin: 40px 0 32px;
}
.authors-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
    gap: 20px 12px;
    margin-top: 10px;
}
.author-card {
    background: transparent;
    text-align: center;
    padding: 6px 2px;
    transition: transform 0.15s;
}
.author-card:hover {
    transform: translateY(-3px);
}
.author-avatar {
    width: 72px;
    height: 72px;
    border-radius: 50%;
    margin: 0 auto 8px;
    overflow: hidden;
    border: 2px solid #fff;
    box-shadow: 0 4px 10px rgba(0,0,0,0.02);
    background-color: #e2e8f0;
}
.author-avatar img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}
.author-name {
    font-weight: 600;
    color: #0b1a2e;
    font-size: 0.9rem;
}

/* ===== FAQ (首页折叠) ===== */
.faq-section {
    margin: 40px 0 32px;
}
.faq-list {
    display: flex;
    flex-direction: column;
    gap: 14px;
    margin-top: 10px;
}
.faq-item {
    background: #ffffff;
    border-radius: 18px;
    border: 1px solid #f1f4f9;
    box-shadow: 0 2px 8px rgba(0,0,0,0.02);
    transition: box-shadow 0.2s;
}
.faq-item:hover {
    box-shadow: 0 6px 16px rgba(0,0,0,0.03);
    border-color: #dce2ec;
}
.faq-question {
    padding: 16px 22px;
    font-weight: 600;
    font-size: 1rem;
    color: #0b1a2e;
    display: flex;
    align-items: center;
    gap: 12px;
    cursor: pointer;
    user-select: none;
    transition: background 0.15s;
    border-radius: 18px;
}
.faq-question:hover {
    background: #f8fafc;
}
.faq-question i {
    color: #3276ff;
    font-size: 1rem;
    width: 18px;
    text-align: center;
}
.faq-question .faq-toggle-icon {
    margin-left: auto;
    color: #94a3b8;
    transition: transform 0.2s;
}
.faq-item.active .faq-question .faq-toggle-icon {
    transform: rotate(180deg);
}
.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease, padding 0.3s ease;
    padding: 0 22px;
    color: #475569;
    line-height: 1.7;
    font-size: 0.95rem;
}
.faq-item.active .faq-answer {
    max-height: 260px;
    padding: 0 22px 18px 22px;
}
.faq-answer a {
    color: #3276ff;
    text-decoration: underline;
}

/* ===== FAQ 独立页面 (常见问题) ===== */
.faq-page-section {
    margin: 0 0 20px;
}
.page-header {
    margin-bottom: 24px;
}
.page-header h1 {
    font-size: 1.8rem;
    font-weight: 700;
    color: #0b1a2e;
    display: flex;
    align-items: center;
    gap: 10px;
}
.page-header h1 i {
    color: #3276ff;
}
.page-header .subtitle {
    color: #64748b;
    font-size: 1rem;
    margin-top: 4px;
}

/* FAQ 分类 Tabs (水平) */
.faq-category-tabs {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 28px;
    border-bottom: 1px solid #e9edf2;
    padding-bottom: 12px;
}
.faq-category-tabs .cat-tab {
    padding: 8px 20px;
    border-radius: 30px;
    font-size: 0.85rem;
    font-weight: 500;
    color: #64748b;
    background: transparent;
    border: 1px solid transparent;
    cursor: pointer;
    transition: all 0.2s;
}
.faq-category-tabs .cat-tab:hover {
    background: #f1f5f9;
    color: #0b1a2e;
}
.faq-category-tabs .cat-tab.active {
    background: #3276ff;
    color: #fff;
    border-color: #3276ff;
}

/* FAQ 独立页面 - 答案增强 */
.faq-answer .highlight-box {
    background: #f1f5f9;
    border-left: 3px solid #3276ff;
    padding: 10px 16px;
    border-radius: 8px;
    margin: 8px 0;
    font-size: 0.9rem;
}
.faq-answer ul,
.faq-answer ol {
    padding-left: 20px;
    margin: 6px 0;
}

/* ===== 底部 ===== */
.footer-pc {
    border-top: 1px solid #e9edf2;
    padding: 20px 0 18px;
    margin-top: 36px;
    color: #64748b;
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 10px;
    font-size: 0.85rem;
}
.footer-pc a {
    color: #3276ff;
}

/* ===== 移动端底部悬浮下载 ===== */
.mobile-bottom-download {
    position: fixed;
    bottom: 0;
    left: 0;
    width: 100%;
    background: rgba(255,255,255,0.92);
    backdrop-filter: blur(8px);
    padding: 10px 20px 14px;
    box-shadow: 0 -4px 16px rgba(0,0,0,0.05);
    border-top: 1px solid #e9edf2;
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 40;
    gap: 12px;
}
.mobile-bottom-download .btn-download {
    width: 100%;
    max-width: 360px;
    justify-content: center;
    padding: 12px 20px;
    font-size: 1rem;
    border-radius: 60px;
}

/* ============================================
   响应式适配
   ============================================ */

/* 平板/小屏笔记本 */
@media screen and (max-width: 1024px) {
    .hero-download {
        flex-direction: column;
        align-items: flex-start;
    }
    .hero-download-right {
        width: 100%;
    }
    .hero-download-right .btn-download {
        width: 100%;
        justify-content: center;
    }
    .category-tabs {
        flex: 0 0 80px;
        min-width: 70px;
    }
    .category-tabs .tab-item {
        font-size: 0.75rem;
        padding: 8px 12px;
    }
}

/* 移动端 */
@media screen and (max-width: 767px) {
    .container {
        padding: 0 14px;
    }
    .nav-right .btn-download {
        display: none;
    }
    .nav-mobile-download {
        display: flex;
        align-items: center;
    }
    .mobile-bottom-download {
        display: flex !important;
    }

    .main-layout {
        flex-direction: column;
        gap: 16px;
        margin-top: 16px;
    }

    /* 左侧导航 → 顶部横向滚动 */
    .category-tabs {
        flex: none;
        width: 100%;
        min-width: unset;
        display: flex;
        flex-wrap: nowrap;
        overflow-x: auto;
        padding: 8px 12px;
        gap: 4px;
        background: #ffffff;
        border-radius: 16px;
        border: 1px solid #eef2f6;
        position: sticky;
        top: 72px;
        z-index: 20;
        box-shadow: 0 2px 8px rgba(0,0,0,0.02);
        align-self: stretch;
        scrollbar-width: none;
    }
    .category-tabs::-webkit-scrollbar {
        display: none;
    }
    .category-tabs .tab-item {
        flex: 0 0 auto;
        border-left: none;
        border-bottom: 2px solid transparent;
        padding: 6px 14px;
        font-size: 0.8rem;
        white-space: nowrap;
        background: transparent;
    }
    .category-tabs .tab-item.active {
        border-left-color: transparent;
        border-bottom-color: #3276ff;
        background: transparent;
    }
    .category-tabs .tab-item:hover {
        background: transparent;
    }

    /* 下载区域 */
    .hero-download {
        padding: 18px 16px;
        margin-bottom: 20px;
    }
    .hero-download-left {
        flex-direction: column;
        align-items: flex-start;
        gap: 12px;
        width: 100%;
    }
    .hero-qrcode {
        width: 100%;
        justify-content: center;
        padding: 6px 12px;
    }
    .hero-qrcode img {
        width: 48px;
        height: 48px;
    }
    .hero-download-text {
        font-size: 1rem;
    }

    /* 热门卡片 */
    .hot-card-content {
        padding: 12px 16px 8px 16px;
    }
    .hot-card-title {
        font-size: 1.05rem;
    }
    .hot-card-image {
        min-height: 140px;
    }

    /* 更新卡片 */
    .update-card-content {
        padding: 12px 16px 8px 16px;
    }
    .update-card-title {
        font-size: 1.05rem;
    }
    .update-card-image {
        min-height: 140px;
    }

    /* 作者 */
    .authors-grid {
        grid-template-columns: repeat(3, 1fr);
        gap: 12px 6px;
    }
    .author-avatar {
        width: 60px;
        height: 60px;
    }

    /* 标题 */
    .section-header h2 {
        font-size: 1.3rem;
    }

    /* FAQ 独立页面 */
    .page-header h1 {
        font-size: 1.4rem;
    }
    .faq-category-tabs {
        gap: 6px;
        padding-bottom: 8px;
    }
    .faq-category-tabs .cat-tab {
        font-size: 0.75rem;
        padding: 6px 14px;
    }

    /* 通用 FAQ */
    .faq-question {
        padding: 12px 16px;
        font-size: 0.9rem;
    }
    .faq-answer {
        font-size: 0.9rem;
    }
    .faq-item.active .faq-answer {
        padding: 0 16px 16px 16px;
    }

    /* 底部 */
    .footer-pc {
        flex-direction: column;
        align-items: center;
        text-align: center;
        padding-bottom: 90px;
    }
}

/* 超小屏 */
@media screen and (max-width: 480px) {
    .authors-grid {
        grid-template-columns: repeat(3, 1fr);
    }
    .logo-text {
        font-size: 18px;
    }
    .hero-download-text small {
        font-size: 0.8rem;
    }
    .faq-category-tabs .cat-tab {
        font-size: 0.7rem;
        padding: 4px 12px;
    }
}

/* ===== 辅助类 ===== */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0,0,0,0);
    border: 0;
}