/* ========== 全局重置（关键！防止错位） ========== */
        *,
        *::before,
        *::after {
            margin: 0;
            padding: 0;
            box-sizing: border-box;  /* 防止padding/border撑大元素 */
        }

        html, body {
            max-width: 100%;
            overflow-x: hidden;
            position: relative;
        }

        body {
            background-color: var(--bg-primary);
            font-family: 'Inter', 'Roboto', sans-serif;
            color: var(--text-primary);
            line-height: 1.5;
            scroll-behavior: smooth;
            transition: background-color 0.3s ease, color 0.2s ease;
            width: 100%;
        }

        /* 全局变量 - 默认亮色主题 */
        :root {
            --bg-primary: #F5F7FA;
            --bg-secondary: rgba(0,0,0,0.02);
            --surface-card: rgba(255,255,255,0.8);
            --border-light: rgba(0,0,0,0.08);
            --text-primary: #1A1F2A;
            --text-secondary: #2C3E50;
            --text-muted: #5A6E7F;
            --accent-blue: #0066b3;
            --accent-glow: rgba(0,102,179,0.1);
            --nav-bg: rgba(245,247,250,0.9);
            --table-header: #E2E8F0;
            --detail-bg: rgba(0,0,0,0.02);
            --qa-bg: rgba(0,0,0,0.02);
            --overlay-dark: rgba(0,0,0,0.5);
        }

        body.dark-theme {
            --bg-primary: #0D0D0D;
            --bg-secondary: rgba(255,255,255,0.04);
            --surface-card: rgba(255,255,255,0.04);
            --border-light: rgba(255,255,255,0.1);
            --text-primary: #E8ECEF;
            --text-secondary: #CDD9ED;
            --text-muted: #A0AAB5;
            --accent-blue: #0077CC;
            --accent-glow: rgba(0,119,204,0.2);
            --nav-bg: rgba(13,13,13,0.85);
            --table-header: #1A1F2A;
            --detail-bg: rgba(255,255,255,0.02);
            --qa-bg: rgba(255,255,255,0.02);
            --overlay-dark: rgba(0,0,0,0.65);
        }

        html {
            scroll-padding-top: 85px;
        }

        /* 自定义滚动条 */
        ::-webkit-scrollbar {
            width: 6px;
        }
        ::-webkit-scrollbar-track {
            background: var(--bg-primary);
        }
        ::-webkit-scrollbar-thumb {
            background: var(--accent-blue);
            border-radius: 8px;
        }

        /* ========== 导航栏 ========== */
        .navbar {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 70px;
            background: var(--nav-bg);
            backdrop-filter: blur(12px);
            border-bottom: 1px solid var(--border-light);
            display: flex;
            align-items: center;
            justify-content: space-between;
            padding: 0 5%;
            z-index: 1000;
        }
        .logo {
            font-weight: 700;
            font-size: 1.4rem;
            background: linear-gradient(135deg, var(--text-primary) 0%, var(--accent-blue) 100%);
            -webkit-background-clip: text;
            background-clip: text;
            color: transparent;
            white-space: nowrap;
        }
        .nav-links {
            display: flex;
            gap: 2rem;
            align-items: center;
        }
        .nav-links a {
            color: var(--text-primary);
            text-decoration: none;
            font-weight: 500;
            font-size: 0.95rem;
            transition: color 0.2s;
            white-space: nowrap;
        }
        .nav-links a:hover {
            color: var(--accent-blue);
        }
        .theme-toggle {
            background: var(--surface-card);
            border: 1px solid var(--border-light);
            border-radius: 40px;
            padding: 0.3rem 1rem;
            cursor: pointer;
            display: flex;
            align-items: center;
            gap: 6px;
            font-size: 0.8rem;
            font-weight: 500;
            color: var(--text-primary);
        }
        .menu-icon {
            display: none;
            font-size: 1.8rem;
            cursor: pointer;
            color: var(--text-primary);
            background: transparent;
            border: none;
        }
        .container {
            max-width: 1400px;
            margin: 0 auto;
            padding: 0 5%;
            width: 100%;
        }

        /* 响应式导航 */
        @media (max-width: 768px) {
            .navbar { padding: 0 5%; height: 64px; }
            .menu-icon { display: block; }
            .nav-links {
                display: none;
                flex-direction: column;
                position: absolute;
                top: 64px;
                left: 0;
                width: 100%;
                background: var(--nav-bg);
                backdrop-filter: blur(20px);
                padding: 1.5rem 0;
                gap: 1.2rem;
                text-align: center;
                border-bottom: 1px solid var(--border-light);
                z-index: 999;
            }
            .nav-links a { white-space: normal; }
            .nav-links.active { display: flex; }
            .theme-toggle { margin: 0 auto; width: fit-content; }
            .container { padding: 0 5%; }
        }

        /* ========== 海报大图区域 ========== */
        .hero-poster {
            position: relative;
            width: 100%;
            min-height: 85vh;
            display: flex;
            align-items: center;
            justify-content: flex-start;
            overflow: hidden;
            margin-top: 70px;
            background-size: cover;
            background-position: center 35%;
            background-repeat: no-repeat;
        }
        .hero-poster::before {
            content: "";
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: var(--overlay-dark);
            z-index: 1;
        }
        .hero-poster-content {
            position: relative;
            z-index: 2;
            max-width: 650px;
            margin-left: 8%;
            padding: 2rem;
            color: white;
            animation: fadeInUp 0.8s ease-out;
        }
        .hero-poster-content h1 {
            font-size: 3rem;
            font-weight: 700;
            margin-bottom: 1rem;
            letter-spacing: -0.02em;
            text-shadow: 0 2px 10px rgba(0,0,0,0.3);
        }
        .hero-poster-content .highlight {
            background: linear-gradient(135deg, #fff 0%, #80c4ff 100%);
            -webkit-background-clip: text;
            background-clip: text;
            color: transparent;
        }
        .hero-poster-content p {
            font-size: 1.1rem;
            line-height: 1.6;
            margin-bottom: 2rem;
            opacity: 0.92;
            text-shadow: 0 1px 3px rgba(0,0,0,0.3);
        }
        .hero-poster-btn {
            display: inline-flex;
            align-items: center;
            gap: 12px;
            background: var(--accent-blue);
            color: white;
            padding: 0.8rem 2rem;
            border-radius: 40px;
            font-weight: 600;
            text-decoration: none;
            transition: transform 0.2s ease, background 0.2s;
            font-size: 1rem;
            border: none;
            cursor: pointer;
        }
        .hero-poster-btn:hover {
            background: #004c8c;
            transform: translateY(-3px);
        }
        @keyframes fadeInUp {
            from { opacity: 0; transform: translateY(30px); }
            to { opacity: 1; transform: translateY(0); }
        }
        @media (max-width: 768px) {
            .hero-poster { min-height: 70vh; margin-top: 64px; }
            .hero-poster-content { margin-left: 0; padding: 1.5rem; text-align: center; width: 100%; }
            .hero-poster-content h1 { font-size: 2rem; }
            .hero-poster-content p { font-size: 1rem; }
            .hero-poster-btn { margin: 0 auto; }
        }

        /* ========== 详细参数模块 ========== */
        .detail-spec-section {
            padding: 70px 0 40px;
            scroll-margin-top: 85px;
            width: 100%;
        }
        .section-title {
            font-size: 1.8rem;
            font-weight: 600;
            margin-bottom: 2rem;
            border-left: 4px solid var(--accent-blue);
            padding-left: 1rem;
            word-break: break-word;
        }
        @media (max-width: 768px) {
            .section-title { font-size: 1.5rem; margin-bottom: 1.5rem; }
            .detail-spec-section { padding: 40px 0 30px; }
        }
        .detail-wrapper {
            background: var(--detail-bg);
            border-radius: 32px;
            border: 1px solid var(--border-light);
            overflow: hidden;
            width: 100%;
        }
        .detail-hero {
            display: flex;
            gap: 2rem;
            padding: 2rem;
            background: var(--surface-card);
            border-bottom: 1px solid var(--border-light);
            flex-wrap: wrap;
        }
        .detail-hero-img {
            flex: 1.2;
            min-width: 200px;
            max-width: 380px;
            border-radius: 24px;
            overflow: hidden;
            aspect-ratio: 4 / 3;
            background: #e9ecef;
        }
        .detail-hero-img img {
            width: 100%;
            height: 100%;
            display: block;
            object-fit: cover;
            object-position: center;
        }
        .detail-hero-content {
            flex: 1;
            min-width: 0;
        }
        .detail-hero-content h3 {
            font-size: 2rem;
            font-weight: 700;
            margin-bottom: 0.5rem;
            color: var(--accent-blue);
        }
        .detail-hero-content .sub {
            font-size: 0.85rem;
            color: var(--text-muted);
            margin-bottom: 1rem;
            text-transform: uppercase;
            letter-spacing: 1px;
        }
        .detail-hero-content p {
            color: var(--text-secondary);
            line-height: 1.6;
            margin-bottom: 1.5rem;
        }
        .action-buttons {
            display: flex;
            gap: 1rem;
            flex-wrap: wrap;
            margin-top: 0.5rem;
        }
        .btn-custom {
            display: inline-flex;
            align-items: center;
            gap: 10px;
            padding: 0.7rem 1.6rem;
            border-radius: 40px;
            font-weight: 600;
            font-size: 0.9rem;
            text-decoration: none;
            transition: all 0.25s ease;
            cursor: pointer;
            border: none;
            background: transparent;
        }
        .btn-primary-custom {
            background: var(--accent-blue);
            color: white;
            border: 1px solid var(--accent-blue);
        }
        .btn-primary-custom:hover {
            background: #004c8c;
            transform: translateY(-2px);
        }
        .btn-outline-custom {
            background: transparent;
            border: 1px solid var(--accent-blue);
            color: var(--accent-blue);
        }
        .btn-outline-custom:hover {
            background: var(--accent-glow);
            transform: translateY(-2px);
        }
        @media (max-width: 768px) {
            .detail-hero-img { max-width: 100%; aspect-ratio: 4 / 3; }
            .action-buttons { justify-content: flex-start; }
            .btn-custom { padding: 0.6rem 1.2rem; font-size: 0.85rem; }
        }
        @media (max-width: 480px) {
            .action-buttons { flex-direction: column; width: 100%; }
            .btn-custom { justify-content: center; width: 100%; }
        }
        .detail-params { padding: 2rem; }
        .detail-params h4 {
            font-size: 1.4rem;
            font-weight: 600;
            margin-bottom: 1.5rem;
            display: flex;
            align-items: center;
            gap: 12px;
            color: var(--accent-blue);
            flex-wrap: wrap;
        }
        
        /* 表格样式 */
        .spec-table-wrapper {
            width: 100%;
            overflow-x: auto;
            margin-bottom: 1rem;
            border-radius: 20px;
            background: var(--bg-secondary);
        }
        .param-table {
            width: 100%;
            border-collapse: collapse;
            background: var(--bg-secondary);
        }
        .param-table th, .param-table td {
            padding: 1rem 1.2rem;
            text-align: left;
            border-bottom: 1px solid var(--border-light);
        }
        .param-table th {
            background: var(--table-header);
            font-weight: 600;
            color: var(--accent-blue);
            width: 30%;
            font-size: 0.95rem;
        }
        .param-table td {
            color: var(--text-secondary);
            font-size: 0.9rem;
        }
        .param-table tr:last-child td, .param-table tr:last-child th { border-bottom: none; }
        
        @media (max-width: 768px) {
            .spec-table-wrapper { overflow-x: visible; background: transparent; }
            .param-table, .param-table thead, .param-table tbody, .param-table tr, .param-table th, .param-table td {
                display: block;
                width: 100%;
            }
            .param-table tr {
                display: block;
                margin-bottom: 1rem;
                background: var(--bg-secondary);
                border-radius: 20px;
                border: 1px solid var(--border-light);
                overflow: hidden;
            }
            .param-table th, .param-table td {
                display: flex;
                justify-content: space-between;
                align-items: center;
                gap: 1rem;
                padding: 0.85rem 1rem;
                border-bottom: 1px solid var(--border-light);
                font-size: 0.85rem;
            }
            .param-table th:last-child, .param-table td:last-child { border-bottom: none; }
            .param-table th { background: var(--table-header); font-weight: 700; color: var(--accent-blue); }
            .param-table td { background: var(--surface-card); color: var(--text-secondary); }
            .detail-params { padding: 1.2rem; }
        }
        
        .text-block {
            margin-top: 2rem;
            padding: 1.5rem;
            background: var(--surface-card);
            border-radius: 24px;
            border-left: 4px solid var(--accent-blue);
        }
        .text-block p {
            color: var(--text-secondary);
            line-height: 1.7;
            font-size: 0.95rem;
        }
        @media (max-width: 768px) {
            .detail-hero { flex-direction: column; padding: 1.5rem; gap: 1.2rem; }
            .detail-hero-content h3 { font-size: 1.6rem; }
            .text-block { padding: 1rem; }
        }

        /* ========== 视频播放器模块（原生 HTML5，完美自适应） ========== */
        .video-showcase-section {
            padding: 50px 0 40px;
            scroll-margin-top: 85px;
            width: 100%;
        }
        .video-grid.single-video {
            display: flex;
            flex-direction: column;
            max-width: 1000px;
            margin: 0 auto;
        }
        .video-card {
            background: var(--surface-card);
            border: 1px solid var(--border-light);
            border-radius: 28px;
            overflow: hidden;
            transition: all 0.3s ease;
        }
        .video-card:hover {
            transform: translateY(-6px);
            border-color: var(--accent-blue);
            box-shadow: 0 20px 30px -12px rgba(0,0,0,0.1);
        }
        .video-wrapper {
            position: relative;
            width: 100%;
            background: #000;
        }
        /* 关键：视频自适应比例，防止错位 */
        .custom-video {
            width: 100%;
            height: auto;
            display: block;
            aspect-ratio: 16 / 9;
            object-fit: cover;
        }
        .video-info {
            padding: 1.2rem 1.5rem 1.5rem;
        }
        .video-info h3 {
            font-size: 1.2rem;
            font-weight: 700;
            margin-bottom: 0.5rem;
            color: var(--accent-blue);
        }
        .video-info p {
            font-size: 0.85rem;
            color: var(--text-secondary);
        }
        @media (max-width: 768px) {
            .video-showcase-section { padding: 40px 0 30px; }
            .video-info h3 { font-size: 1rem; }
        }

        /* ========== 问答模块 ========== */
        .qa-section {
            padding: 50px 0 40px;
            scroll-margin-top: 85px;
            width: 100%;
        }
        .qa-grid {
            display: flex;
            flex-direction: column;
            gap: 1rem;
        }
        .qa-item {
            background: var(--qa-bg);
            border: 1px solid var(--border-light);
            border-radius: 24px;
            overflow: hidden;
        }
        .qa-question {
            padding: 1.2rem 1.5rem;
            background: var(--surface-card);
            font-weight: 700;
            font-size: 1.05rem;
            cursor: pointer;
            display: flex;
            justify-content: space-between;
            align-items: center;
            gap: 1rem;
        }
        .qa-question i {
            color: var(--accent-blue);
            transition: transform 0.25s ease;
        }
        .qa-question.active i {
            transform: rotate(180deg);
        }
        .qa-answer {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.35s ease;
            padding: 0 1.5rem;
            color: var(--text-secondary);
        }
        .qa-answer.show {
            max-height: 300px;
            padding: 1rem 1.5rem 1.3rem;
            border-top: 1px solid var(--border-light);
        }
        @media (max-width: 768px) {
            .qa-section { padding: 40px 0 30px; }
            .qa-question { font-size: 0.95rem; padding: 1rem 1.2rem; }
        }

        /* ========== 下载模块 ========== */
        .resources-section {
            padding: 50px 0 50px;
            scroll-margin-top: 85px;
        }
        .download-grid {
            display: grid;
            grid-template-columns: repeat(2, 1fr);
            gap: 1.5rem;
        }
        .download-card {
            background: var(--surface-card);
            border: 1px solid var(--border-light);
            border-radius: 24px;
            padding: 1.2rem 1.5rem;
            display: flex;
            align-items: center;
            justify-content: space-between;
            flex-wrap: wrap;
            gap: 1rem;
        }
        .download-card:hover {
            transform: translateY(-4px);
            border-color: var(--accent-blue);
        }
        .download-info {
            display: flex;
            align-items: center;
            gap: 1rem;
            flex: 2;
            min-width: 160px;
        }
        .download-info i {
            font-size: 1.8rem;
            color: var(--accent-blue);
        }
        .download-details h4 {
            font-size: 1rem;
            font-weight: 600;
            margin-bottom: 0.2rem;
        }
        .download-meta {
            font-size: 0.7rem;
            color: var(--text-muted);
        }
        .download-btn-sm {
            background: transparent;
            border: 1px solid var(--accent-blue);
            border-radius: 40px;
            padding: 0.5rem 1.2rem;
            font-size: 0.75rem;
            font-weight: 500;
            color: var(--accent-blue);
            cursor: pointer;
            display: inline-flex;
            align-items: center;
            gap: 8px;
            white-space: nowrap;
        }
        .download-btn-sm:hover {
            background: var(--accent-blue);
            color: white;
        }
        @media (max-width: 768px) {
            .download-grid { grid-template-columns: 1fr; gap: 1rem; }
            .download-card { padding: 1rem; justify-content: center; }
            .download-info { justify-content: center; }
            .resources-section { padding: 40px 0; }
        }

        .footer {
            padding: 2rem 0;
            border-top: 1px solid var(--border-light);
            text-align: center;
            font-size: 0.8rem;
            color: var(--text-muted);
        }
        @media (max-width: 768px) {
            .footer { padding: 1.5rem 0; font-size: 0.7rem; }
        }