/* ==================== 语言切换与防闪烁规则 ==================== */
        html.lang-zh .content-en,
        html.lang-zh .content-ja,
        html.lang-zh .content-ko,
        html.lang-en .content-zh,
        html.lang-en .content-ja,
        html.lang-en .content-ko,
        html.lang-ja .content-zh,
        html.lang-ja .content-en,
        html.lang-ja .content-ko,
        html.lang-ko .content-zh,
        html.lang-ko .content-en,
        html.lang-ko .content-ja,
        body.lang-zh .content-en,
        body.lang-zh .content-ja,
        body.lang-zh .content-ko,
        body.lang-en .content-zh,
        body.lang-en .content-ja,
        body.lang-en .content-ko,
        body.lang-ja .content-zh,
        body.lang-ja .content-en,
        body.lang-ja .content-ko,
        body.lang-ko .content-zh,
        body.lang-ko .content-en,
        body.lang-ko .content-ja,
        html:not([class*="lang-"]) body:not([class*="lang-"]) .content-en,
        html:not([class*="lang-"]) body:not([class*="lang-"]) .content-ja,
        html:not([class*="lang-"]) body:not([class*="lang-"]) .content-ko {
            display: none !important;
        }

        /* ==================== CSS 变量 ==================== */
        :root {
            --paper-white: #fefdfb;
            --paper-cream: #f9f6f0;
            --paper-yellow: #fff9e6;
            --paper-pink: #fff0f5;
            --paper-blue: #f0f8ff;
            --paper-green: #f0fff4;
            --line-color: #d4c5b9;
            --ink-dark: #2c2416;
            --ink-medium: #5a4a3a;
            --ink-light: #8b7355;
            --accent-brown: #a67c52;
            --accent-orange: #d4895b;
            --accent-blue: #5d94b8;
            --accent-green: #7ca982;
            --accent-red: #c66b6b;
            --shadow-soft: rgba(0, 0, 0, 0.08);
            --shadow-medium: rgba(0, 0, 0, 0.12);
            --shadow-hard: rgba(0, 0, 0, 0.2);
            --nav-bg: rgba(254, 253, 251, 0.85); /* 浅色模式半透明背景 */
        }

        [data-theme="dark"] {
            --paper-white: #2a2520;
            --paper-cream: #342e28;
            --paper-yellow: #3d3630;
            --paper-pink: #3d3035;
            --paper-blue: #2d3540;
            --paper-green: #2d3a30;
            --line-color: #4a4037;
            --ink-dark: #e8dfd5;
            --ink-medium: #d4c5b9;
            --ink-light: #b8a99a;
            --nav-bg: rgba(42, 37, 32, 0.85); /* 深色模式半透明背景 */
        }

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

        html {
            scroll-behavior: smooth;
            scroll-padding-top: 90px; /* 防止固定导航栏遮挡锚点内容 */
        }

        body {
            font-family: 'Noto Sans SC', 'Noto Sans', 'ZCOOL XiaoWei', serif;
            background: var(--paper-cream);
            color: var(--ink-dark);
            line-height: 1.8;
            overflow-x: hidden;
            position: relative;
            transition: background 0.3s ease, color 0.3s ease;
        }

        /* ==================== 全局 UI 优化 ==================== */
        ::-webkit-scrollbar {
            width: 10px;
            height: 10px;
        }
        ::-webkit-scrollbar-track {
            background: var(--paper-cream);
        }
        ::-webkit-scrollbar-thumb {
            background: var(--line-color);
            border-radius: 5px;
            border: 2px solid var(--paper-cream);
        }
        ::-webkit-scrollbar-thumb:hover {
            background: var(--accent-brown);
        }

        ::selection {
            background: var(--accent-brown);
            color: var(--paper-white);
        }

        /* ==================== 可访问性与交互一致性 ==================== */
        :focus-visible {
            outline: 3px solid var(--accent-blue);
            outline-offset: 3px;
        }

        a, button {
            -webkit-tap-highlight-color: transparent;
        }

        .skip-link {
            position: absolute;
            left: 12px;
            top: 12px;
            z-index: 3000;
            padding: 0.7rem 1rem;
            background: var(--paper-white);
            color: var(--ink-dark);
            border: 2px solid var(--accent-blue);
            border-radius: 10px;
            box-shadow: 4px 4px 0 var(--shadow-hard);
            text-decoration: none;
            transform: translateY(-200%);
            transition: transform 0.2s ease;
        }

        .skip-link:focus-visible {
            transform: translateY(0);
        }

        /* 用户偏好：减少动画 */
        @media (prefers-reduced-motion: reduce) {
            html {
                scroll-behavior: auto;
            }
            *, *::before, *::after {
                animation-duration: 0.001ms !important;
                animation-iteration-count: 1 !important;
                transition-duration: 0.001ms !important;
            }
        }

        html.lang-en body,
        body.lang-en {
            font-family: 'Noto Sans', 'Noto Sans SC', 'ZCOOL XiaoWei', serif;
        }

        html.lang-ja body,
        body.lang-ja {
            font-family: 'Noto Sans JP', 'Noto Sans SC', 'Noto Sans', sans-serif;
        }

        html.lang-ko body,
        body.lang-ko {
            font-family: 'Noto Sans KR', 'Noto Sans SC', 'Noto Sans', sans-serif;
        }

        html.lang-ja .hero h1,
        html.lang-ja h2.section-title,
        body.lang-ja .hero h1,
        body.lang-ja h2.section-title {
            font-family: 'Noto Serif JP', 'Noto Serif SC', serif;
        }

        html.lang-ko .hero h1,
        html.lang-ko h2.section-title,
        body.lang-ko .hero h1,
        body.lang-ko h2.section-title {
            font-family: 'Noto Serif KR', 'Noto Serif SC', serif;
        }

        body::before {
            content: '';
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background-image: 
                repeating-linear-gradient(0deg, transparent, transparent 32px, var(--line-color) 32px, var(--line-color) 33px),
                url("data:image/svg+xml,%3Csvg viewBox='0 0 400 400' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)' opacity='0.03'/%3E%3C/svg%3E");
            opacity: 0.35;
            z-index: -1;
            pointer-events: none;
        }

        .handwriting {
            font-family: 'Caveat', 'Long Cang', cursive;
        }

        html.lang-en .handwriting,
        body.lang-en .handwriting {
            font-family: 'Caveat', cursive;
        }

        html.lang-ja .handwriting,
        body.lang-ja .handwriting {
            font-family: 'Caveat', 'Noto Sans JP', cursive;
        }

        html.lang-ko .handwriting,
        body.lang-ko .handwriting {
            font-family: 'Caveat', 'Noto Sans KR', cursive;
        }

        /* ==================== 导航栏 ==================== */
        nav {
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            z-index: 1000;
            background: var(--nav-bg);
            border-bottom: 3px solid var(--accent-brown);
            box-shadow: 0 3px 12px var(--shadow-soft);
            backdrop-filter: blur(12px); /* 毛玻璃效果 */
            -webkit-backdrop-filter: blur(12px);
            padding-top: env(safe-area-inset-top);
        }

        .nav-container {
            max-width: 1400px;
            margin: 0 auto;
            padding: 0.75rem clamp(0.75rem, 2.5vw, 2.5rem);
            display: flex;
            justify-content: space-between;
            align-items: center;
            position: relative;
            z-index: 1001; /* Ensure nav items are above overlay */
            gap: clamp(0.5rem, 1.5vw, 1.5rem);
            min-width: 0;
        }

        .nav-brand {
            display: flex;
            align-items: center;
            gap: clamp(0.4rem, 1vw, 0.75rem);
            text-decoration: none;
            color: var(--ink-dark);
            transition: transform 0.3s ease;
            min-width: 0;
            flex-shrink: 1;
        }

        .nav-brand:hover {
            transform: translateY(-2px);
        }

        .nav-logo {
            width: clamp(32px, 3.5vw, 42px);
            height: clamp(32px, 3.5vw, 42px);
            display: flex;
            align-items: center;
            justify-content: center;
            flex-shrink: 0;
        }

        .nav-logo img {
            width: 100%;
            height: 100%;
            object-fit: contain;
        }

        .nav-title {
            font-size: clamp(1.15rem, 2vw, 1.6rem);
            font-weight: 700;
            color: var(--ink-dark);
            font-family: 'ZCOOL XiaoWei', serif;
            white-space: nowrap;
            overflow: hidden;
            text-overflow: ellipsis;
        }

        body.lang-en .nav-title,
        body.lang-ja .nav-title,
        body.lang-ko .nav-title {
            font-size: clamp(1rem, 1.6vw, 1.35rem);
            font-family: var(--font-sans, 'Noto Sans', sans-serif);
        }

        .nav-links {
            display: flex;
            gap: clamp(1rem, 1.8vw, 2.2rem);
            list-style: none;
            align-items: center;
            flex-shrink: 0;
        }

        .nav-links a {
            color: var(--ink-medium);
            text-decoration: none;
            font-weight: 500;
            position: relative;
            padding: 0.25rem 0;
            transition: color 0.3s ease;
            display: inline-block; /* Fix alignment */
            font-size: clamp(0.9rem, 1vw, 1rem);
            white-space: nowrap;
        }

        .nav-links a::after {
            content: '';
            position: absolute;
            bottom: -3px;
            left: 0;
            width: 0;
            height: 2px;
            background: var(--accent-brown);
            transition: width 0.3s ease;
            border-radius: 2px;
        }

        .nav-links a:hover {
            color: var(--accent-brown);
        }

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

        .nav-links a.active {
            color: var(--accent-brown);
        }
        .nav-links a.active::after {
            width: 100%;
        }

        .nav-actions {
            position: relative;
            z-index: 1001;
            display: flex;
            gap: clamp(0.4rem, 1vw, 0.85rem);
            align-items: center;
            flex-shrink: 0;
        }

        .mobile-nav-dl {
            display: none;
        }

        .theme-toggle {
            width: 44px;
            height: 44px;
            border: 2px solid var(--accent-brown);
            background: var(--paper-yellow);
            border-radius: 8px;
            cursor: pointer;
            font-size: 1.3rem;
            display: flex;
            align-items: center;
            justify-content: center;
            transition: all 0.3s ease;
            box-shadow: 2px 2px 4px var(--shadow-soft);
        }

        .theme-toggle:hover {
            transform: scale(1.05);
            box-shadow: 3px 3px 8px var(--shadow-medium);
        }

        .lang-selector-wrapper {
            position: relative;
            display: inline-block;
        }

        .lang-toggle {
            width: 44px;
            height: 44px;
            border: 2px solid var(--accent-blue);
            background: var(--paper-blue);
            border-radius: 8px;
            cursor: pointer;
            font-size: 1.3rem;
            display: flex;
            align-items: center;
            justify-content: center;
            transition: all 0.3s ease;
            box-shadow: 2px 2px 4px var(--shadow-soft);
            color: var(--accent-blue);
            padding: 0;
        }

        .lang-toggle:hover,
        .lang-toggle[aria-expanded="true"] {
            transform: scale(1.05);
            box-shadow: 3px 3px 8px var(--shadow-medium);
            background: var(--accent-blue);
            color: var(--paper-white);
        }

        .lang-dropdown {
            position: absolute;
            top: calc(100% + 8px);
            right: 0;
            min-width: 120px;
            background: var(--paper-white);
            border: 2px solid var(--line-color);
            border-radius: 8px;
            box-shadow: 4px 4px 12px var(--shadow-medium);
            padding: 6px;
            display: none;
            flex-direction: column;
            gap: 4px;
            z-index: 1005;
        }

        .lang-dropdown.active {
            display: flex;
            animation: fadeInDropdown 0.15s ease-out;
        }

        @keyframes fadeInDropdown {
            from { opacity: 0; transform: translateY(-4px); }
            to { opacity: 1; transform: translateY(0); }
        }

        .lang-option {
            display: flex;
            align-items: center;
            justify-content: space-between;
            padding: 8px 12px;
            border: none;
            background: transparent;
            color: var(--ink-dark);
            font-size: 0.88rem;
            font-weight: 500;
            border-radius: 6px;
            cursor: pointer;
            text-align: left;
            transition: all 0.15s ease;
            width: 100%;
            white-space: nowrap;
        }

        .lang-option:hover,
        .lang-option:focus-visible {
            background: var(--paper-cream);
            color: var(--accent-brown);
        }

        .lang-option.active {
            background: var(--paper-yellow);
            color: var(--accent-brown);
            font-weight: 700;
        }

        .lang-option.active::after {
            content: '✓';
            font-weight: 700;
            color: var(--accent-brown);
        }

        .btn-notebook {
            padding: 0.7rem 1.8rem;
            background: var(--accent-brown);
            color: var(--paper-white);
            border: none;
            border-radius: 8px;
            font-weight: 600;
            cursor: pointer;
            text-decoration: none;
            display: inline-block;
            box-shadow: 4px 4px 0 var(--shadow-hard);
            transition: all 0.2s ease;
            font-size: 1rem;
        }

        .btn-notebook:hover {
            transform: translate(2px, 2px);
            box-shadow: 2px 2px 0 var(--shadow-hard);
        }

        .mobile-menu-btn {
            display: none;
            width: 44px;
            height: 44px;
            border: 2px solid var(--accent-brown);
            background: var(--paper-yellow);
            border-radius: 8px;
            cursor: pointer;
            font-size: 1.5rem;
            align-items: center;
            justify-content: center;
            box-shadow: 2px 2px 4px var(--shadow-soft);
            color: var(--accent-brown);
            transition: all 0.3s ease;
        }

        .mobile-menu-btn:hover {
            transform: scale(1.05);
            box-shadow: 3px 3px 8px var(--shadow-medium);
        }

        .mobile-menu-overlay {
            display: none;
        }

        /* ==================== Hero 区域 ==================== */
        .hero {
            min-height: auto;
            display: flex;
            align-items: center;
            justify-content: center;
            padding: 5.5rem 2rem 4rem;
            position: relative;
            overflow: hidden;
        }

        .doodle-decoration {
            position: absolute;
            opacity: 0.08;
            pointer-events: none;
        }

        .doodle-1 {
            top: 15%;
            right: 8%;
            width: 120px;
            height: 120px;
            background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 100 100'%3E%3Cpath d='M50,10 Q30,30 50,50 T50,90' stroke='%23a67c52' stroke-width='3' fill='none' stroke-linecap='round'/%3E%3Ccircle cx='50' cy='50' r='8' fill='%23a67c52'/%3E%3C/svg%3E");
            animation: float 8s ease-in-out infinite;
        }

        @keyframes float {
            0%, 100% { transform: translateY(0) rotate(0deg); }
            50% { transform: translateY(-25px) rotate(-3deg); }
        }

        .hero-container {
            max-width: 1400px;
            width: 100%;
            display: grid;
            grid-template-columns: 1.2fr 1fr;
            gap: 5rem;
            align-items: center;
        }

        .hero-content {
            padding: 1rem 0 2rem;
        }

        .hero-tag {
            display: inline-block;
            background: var(--accent-orange);
            color: var(--paper-white);
            padding: 0.5rem 1.5rem;
            border-radius: 25px;
            font-size: 0.9rem;
            font-weight: 600;
            margin-bottom: 2rem;
            box-shadow: 3px 3px 8px var(--shadow-medium);
        }

        .hero h1 {
            font-size: 4rem;
            font-weight: 700;
            color: var(--ink-dark);
            margin-bottom: 2rem;
            line-height: 1.2;
            font-family: 'ZCOOL XiaoWei', serif;
        }

        .hero-subtitle {
            font-size: 1.4rem;
            color: var(--ink-medium);
            margin-bottom: 2.5rem;
            line-height: 2;
        }

        .hero-warning {
            background: var(--paper-yellow);
            border-left: 4px solid var(--accent-orange);
            padding: 1rem 1.5rem;
            margin-bottom: 2.5rem;
            border-radius: 6px;
            box-shadow: 2px 2px 6px var(--shadow-soft);
        }

        .hero-warning strong {
            color: var(--accent-red);
        }

        .hero-buttons {
            display: flex;
            gap: 1rem;
            flex-wrap: wrap;
            align-items: center;
        }

        .btn-primary {
            padding: 0.9rem 1.8rem;
            background: var(--accent-brown);
            color: var(--paper-white);
            border: none;
            border-radius: 10px;
            font-weight: 600;
            font-size: 1.05rem;
            cursor: pointer;
            text-decoration: none;
            display: inline-flex;
            align-items: center;
            gap: 0.5rem;
            box-shadow: 4px 4px 0 var(--shadow-hard);
            transition: all 0.2s ease;
        }

        .btn-primary:hover {
            transform: translate(2px, 2px);
            box-shadow: 2px 2px 0 var(--shadow-hard);
        }

        .btn-secondary {
            padding: 0.85rem 1.6rem;
            background: rgba(255, 255, 255, 0.4);
            backdrop-filter: blur(8px);
            -webkit-backdrop-filter: blur(8px);
            color: var(--accent-brown);
            border: 2px solid var(--accent-brown);
            border-radius: 10px;
            font-weight: 600;
            font-size: 1.05rem;
            cursor: pointer;
            text-decoration: none;
            display: inline-flex;
            align-items: center;
            gap: 0.5rem;
            transition: all 0.25s ease;
        }

        .btn-secondary:hover {
            background: var(--accent-brown);
            color: var(--paper-white);
            transform: translateY(-2px);
            box-shadow: 0 4px 12px var(--shadow-soft);
        }

        .hero-notebook {
            perspective: 1500px;
            animation: notebookFloat 6s ease-in-out infinite;
        }

        @keyframes notebookFloat {
            0%, 100% { transform: translateY(0); }
            50% { transform: translateY(-15px); }
        }

        .notebook-page {
            background: var(--paper-white);
            border: 3px solid var(--accent-brown);
            border-radius: 15px;
            padding: 3.5rem 3rem;
            box-shadow: 
                10px 10px 0 var(--paper-yellow),
                10px 10px 0 3px var(--accent-brown),
                15px 15px 25px var(--shadow-medium);
            position: relative;
            transform: rotateY(-5deg);
            transition: transform 0.5s ease;
        }

        .notebook-page:hover {
            transform: rotateY(0deg);
        }

        .binding-holes {
            position: absolute;
            left: 2rem;
            top: 3.5rem;
            bottom: 3.5rem;
            width: 24px;
            display: flex;
            flex-direction: column;
            justify-content: space-around;
        }

        .hole {
            width: 14px;
            height: 14px;
            border: 2px solid var(--accent-brown);
            border-radius: 50%;
            background: var(--paper-cream);
        }

        .notebook-content {
            margin-left: 2.5rem;
        }

        .notebook-content h3 {
            font-family: 'Caveat', cursive;
            font-size: 2.2rem;
            color: var(--ink-dark);
            margin-bottom: 2rem;
            border-bottom: 2px dashed var(--line-color);
            padding-bottom: 1rem;
        }

        .notebook-list {
            list-style: none;
            display: flex;
            flex-direction: column;
            justify-content: center;
            min-height: 200px;
        }

        .notebook-list li {
            font-size: 1.15rem;
            font-size: 1.3rem; /* 字号加大，更清晰 */
            color: var(--ink-medium);
            margin-bottom: 1.2rem;
            margin-bottom: 1.6rem; /* 间距加大，更透气 */
            padding-left: 2rem;
            position: relative;
            font-family: 'Caveat', 'Long Cang', cursive;
            transition: transform 0.3s ease, color 0.3s ease;
            cursor: pointer;
        }

        .notebook-list a {
            text-decoration: none;
            color: inherit;
            display: block;
        }

        .notebook-list li:hover {
            transform: translateX(10px);
            color: var(--accent-brown);
        }

        body.lang-en .notebook-list li {
            font-family: 'Caveat', cursive;
        }

        .notebook-list li::before {
            content: '✓';
            position: absolute;
            left: 0;
            color: var(--accent-green);
            font-weight: bold;
            font-size: 1.5rem;
        }

        /* ==================== 通用区域样式 ==================== */
        .section {
            padding: 5rem 2rem;
        }

        .section-header {
            text-align: center;
            max-width: 900px;
            margin: 0 auto 4rem;
        }

        .section-label {
            display: inline-block;
            background: var(--accent-blue);
            color: var(--paper-white);
            padding: 0.6rem 1.8rem;
            border-radius: 25px;
            font-size: 0.95rem;
            font-weight: 600;
            margin-bottom: 1.5rem;
            box-shadow: 3px 3px 8px var(--shadow-medium);
        }

        .section-title {
            font-size: 3.2rem;
            font-weight: 700;
            color: var(--ink-dark);
            margin-bottom: 1.5rem;
            font-family: 'ZCOOL XiaoWei', serif;
        }

        .text-gradient {
            background: linear-gradient(120deg, var(--accent-brown), var(--accent-orange), var(--accent-blue));
            -webkit-background-clip: text;
            background-clip: text;
            color: transparent;
        }

        .section-description {
            font-size: 1.25rem;
            color: var(--ink-light);
            line-height: 2;
        }

        /* ==================== 功能特性 ==================== */
        .features-section {
            background: var(--paper-cream);
        }

        .features-grid {
            max-width: 1400px;
            margin: 0 auto;
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(290px, 1fr));
            gap: clamp(1.25rem, 2vw, 2.5rem);
        }

        .feature-category {
            margin-bottom: 6rem;
        }

        .feature-category-header {
            text-align: center;
            margin-bottom: 3rem;
        }

        /* 桌面及平板端：左右交替布局，增加阅读趣味性 */
        @media (min-width: 721px) {
            .feature-category:nth-of-type(odd) .feature-category-header {
                text-align: left;
                border-left: 5px solid var(--accent-brown);
                padding-left: 2rem;
            }
            .feature-category:nth-of-type(odd) .feature-category-desc {
                margin: 0;
            }

            .feature-category:nth-of-type(even) .feature-category-header {
                text-align: right;
                border-right: 5px solid var(--accent-blue);
                padding-right: 2rem;
            }
            .feature-category:nth-of-type(even) .feature-category-desc {
                margin-left: auto; 
                margin-right: 0;
            }
        }

        .feature-category-title {
            font-family: 'ZCOOL XiaoWei', serif;
            font-size: 2.2rem;
            color: var(--accent-brown);
            margin-bottom: 1rem;
        }

        .feature-category-desc {
            font-size: 1.1rem;
            color: var(--ink-medium);
            max-width: 600px;
            margin: 0 auto;
            line-height: 1.6;
        }

        .sticky-note {
            background: var(--paper-yellow);
            border-radius: 6px;
            background: var(--paper-white);
            border: 1px solid var(--line-color);
            border-radius: 16px;
            padding: 2.5rem 2.2rem;
            box-shadow: 0 5px 8px var(--shadow-soft), 0 12px 25px var(--shadow-soft);
            box-shadow: 0 4px 12px var(--shadow-soft);
            position: relative;
            transform: rotate(-1.5deg);
            transition: all 0.4s ease;
            cursor: default; /* UX优化：非链接卡片不显示手型光标，避免误导点击 */
            height: 100%;
        }

        .sticky-note:nth-child(2n) {
            transform: rotate(1.5deg);
            background: var(--paper-pink);
        }

        .sticky-note:nth-child(3n) {
            background: var(--paper-blue);
        }

        .sticky-note:nth-child(5n) {
            background: var(--paper-green);
        }

        .sticky-note:hover {
            transform: rotate(0deg) scale(1.05) translateY(-8px);
            box-shadow: 0 10px 15px var(--shadow-medium), 0 20px 40px var(--shadow-medium);
            transform: translateY(-8px);
            box-shadow: 0 12px 30px var(--shadow-medium);
            border-color: var(--accent-brown);
            z-index: 10;
        }

        .sticky-note::before {
            content: '';
            position: absolute;
            top: -10px;
            left: 50%;
            transform: translateX(-50%);
            width: 80px;
            height: 20px;
            background: rgba(255, 255, 255, 0.25);
            backdrop-filter: blur(2px); /* 胶带磨砂质感 */
            box-shadow: 0 2px 4px var(--shadow-soft);
            border: none;
        }

        .feature-icon {
            font-size: 3rem;
            margin-bottom: 1.5rem;
            display: block;
        }

        .feature-title {
            font-size: 1.6rem;
            font-weight: 700;
            color: var(--ink-dark);
            margin-bottom: 1rem;
            font-family: 'ZCOOL XiaoWei', serif;
        }

        .feature-description {
            font-size: 1.05rem;
            color: var(--ink-medium);
            line-height: 1.8;
            margin-bottom: 1.2rem;
        }

        .feature-list {
            list-style: none;
        }

        .feature-list li {
            padding: 0.5rem 0;
            color: var(--ink-medium);
            display: flex;
            align-items: center;
            gap: 0.6rem;
        }

        .feature-list li::before {
            content: '◆';
            color: var(--accent-brown);
        }

        /* ==================== 应用截图 ==================== */
        .screenshots-section {
            background: var(--paper-cream);
            position: relative;
        }

        .screenshots-grid {
            max-width: 1400px;
            margin: 0 auto;
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
            gap: 2rem;
            padding: 0 1rem;
        }

        .screenshot-card {
            position: relative;
            background: var(--paper-white);
            border-radius: 12px;
            overflow: hidden;
            box-shadow: 4px 4px 12px var(--shadow-soft);
            transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
            cursor: pointer;
        }

        .screenshot-card::before {
            content: '';
            position: absolute;
            top: -2px;
            left: -2px;
            right: -2px;
            bottom: -2px;
            background: linear-gradient(45deg, var(--accent-brown), var(--accent-orange), var(--accent-blue));
            border-radius: 12px;
            opacity: 0;
            transition: opacity 0.3s ease;
            z-index: -1;
        }

        .screenshot-card:hover {
            transform: translateY(-8px) rotate(0deg);
            box-shadow: 8px 12px 24px var(--shadow-medium);
        }

        .screenshot-card:hover::before {
            opacity: 1;
        }

        .screenshot-image-wrapper {
            position: relative;
            width: 100%;
            height: auto;
            overflow: hidden;
            background: var(--paper-cream);
        }

        .screenshot-card img {
            width: 100%;
            height: auto;
            display: block;
            transition: transform 0.4s ease;
        }

        .screenshot-card:hover img {
            transform: scale(1.05);
        }

        .screenshot-overlay {
            position: absolute;
            bottom: 0;
            left: 0;
            right: 0;
            background: linear-gradient(to top, rgba(0,0,0,0.8), transparent);
            padding: 1.5rem 1rem 1rem;
            transform: translateY(0);
            transition: transform 0.3s ease;
        }

        .screenshot-card:hover .screenshot-overlay {
            transform: translateY(0);
        }

        .screenshot-title {
            color: white;
            font-size: 1rem;
            font-weight: 600;
            margin: 0;
            text-shadow: 0 2px 4px rgba(0,0,0,0.3);
        }

        .screenshot-badge {
            position: absolute;
            top: 12px;
            right: 12px;
            background: var(--accent-orange);
            color: white;
            padding: 0.4rem 0.8rem;
            border-radius: 20px;
            font-size: 0.75rem;
            font-weight: 600;
            box-shadow: 2px 2px 8px var(--shadow-medium);
            z-index: 1;
        }
        .screenshot-item {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: clamp(1.5rem, 3vw, 3.5rem);
            align-items: center;
            max-width: 1000px;
            margin: 0.75rem auto 2rem;
            padding: clamp(1.5rem, 2.5vw, 2.5rem) clamp(1.5rem, 3vw, 3rem);
            background: var(--paper-white);
            border-radius: 18px;
            border: 2px solid var(--line-color);
            box-shadow: 0 6px 24px var(--shadow-soft);
            transition: transform 0.4s cubic-bezier(0.25, 0.8, 0.25, 1), box-shadow 0.4s ease, border-color 0.3s ease;
            position: relative;
        }

        .screenshot-item:hover {
            transform: translateY(-4px);
            box-shadow: 0 16px 36px var(--shadow-medium);
            border-color: var(--accent-brown);
        }

        .screenshot-image {
            position: relative;
            cursor: pointer;
            width: 100%;
            max-width: 270px;
            margin: 0 auto;
            display: flex;
            justify-content: center;
            align-items: center;
            border-radius: 20px;
            padding: 6px;
            background: var(--paper-cream);
            border: 1.5px solid var(--line-color);
            box-shadow: 0 12px 28px rgba(44, 36, 27, 0.14), 0 2px 6px rgba(44, 36, 27, 0.08);
            transition: transform 0.3s cubic-bezier(0.25, 0.8, 0.25, 1), box-shadow 0.3s ease;
        }

        .screenshot-image img {
            width: 100%;
            height: auto;
            max-height: 520px;
            object-fit: cover;
            border-radius: 14px;
            display: block;
        }

        .screenshot-image:hover {
            transform: scale(1.02);
            box-shadow: 0 18px 36px rgba(44, 36, 27, 0.2), 0 4px 10px rgba(44, 36, 27, 0.1);
        }

        .screenshot-content {
            position: relative;
            padding: 1rem 0;
        }

        .screenshot-content h4 {
            font-size: 1.8rem;
            font-weight: 700;
            color: var(--ink-dark);
            margin-bottom: 1rem;
            font-family: 'ZCOOL XiaoWei', serif;
        }

        .screenshot-content p {
            font-size: 1.1rem;
            color: var(--ink-medium);
            line-height: 1.9;
            margin-bottom: 1.5rem;
        }

        .arrow-doodle {
            position: absolute;
            width: 80px;
            height: 80px;
            opacity: 0.25;
            pointer-events: none;
            top: 50%;
            transform: translateY(-50%);
            background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 100 100' fill='none' stroke='%23a67c52' stroke-width='3' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M20,50 Q50,20 80,50'/%3E%3Cpath d='M70,40 L80,50 L70,60'/%3E%3C/svg%3E");
            background-repeat: no-repeat;
            background-size: contain;
        }

        .screenshot-image + .screenshot-content .arrow-doodle {
            left: -70px;
            transform: translateY(-50%) scaleX(-1) rotate(-8deg);
        }

        .screenshot-content:first-child .arrow-doodle {
            right: -70px;
            transform: translateY(-50%) rotate(8deg);
        }

        


        .screenshot-doodle {
            position: absolute;
            opacity: 0.15;
            pointer-events: none;
            z-index: 0;
        }

        .doodle-star {
            top: 10%;
            right: 5%;
            width: 60px;
            height: 60px;
            color: var(--accent-orange);
            animation: rotate 20s linear infinite;
        }

        .doodle-heart {
            bottom: 15%;
            left: 8%;
            width: 50px;
            height: 50px;
            color: var(--accent-red);
            animation: pulse 3s ease-in-out infinite;
        }

        @keyframes rotate {
            from { transform: rotate(0deg); }
            to { transform: rotate(360deg); }
        }

        @keyframes pulse {
            0%, 100% { transform: scale(1); }
            50% { transform: scale(1.1); }
        }

        .screenshot-category {
            margin-bottom: 3rem;
        }

        .category-title {
            font-size: 1.6rem;
            color: var(--ink-dark);
            font-weight: 700;
            margin-bottom: 1.5rem;
            padding-left: 1rem;
            border-left: 4px solid var(--accent-brown);
            font-family: 'ZCOOL XiaoWei', serif;
        }

        .feature-tags {
            display: flex;
            flex-wrap: wrap;
            gap: 0.8rem;
            margin-top: 1.5rem;
        }

        .feature-tag {
            background: var(--paper-yellow);
            color: var(--accent-brown);
            padding: 0.5rem 1rem;
            border-radius: 20px;
            font-size: 0.9rem;
            font-weight: 600;
            border: 2px solid var(--accent-brown);
        }

        /* ==================== 截图轮播（Carousel）==================== */
        .carousel-container {
            max-width: 1400px;
            margin: 0 auto;
            position: relative;
            padding: 1rem clamp(3.25rem, 4.5vw, 4rem) 2rem;
        }

        .carousel-track-container {
            overflow: hidden;
            border-radius: 20px;
            padding: 1.25rem 0.5rem;
            margin: -1.25rem -0.5rem;
        }

        .carousel-track {
            list-style: none;
            padding: 0;
            margin: 0;
            display: flex;
            transition: transform 0.55s cubic-bezier(0.4, 0, 0.2, 1);
            will-change: transform;
        }

        .carousel-slide {
            padding: 0.5rem 1rem;
            flex-shrink: 0;
            width: 100%; /* Ensure slide doesn't shrink */
        }

        .carousel-btn {
            position: absolute;
            top: 50%;
            transform: translateY(-50%);
            width: 46px;
            height: 46px;
            border-radius: 50%;
            border: 2px solid rgba(255, 255, 255, 0.6);
            background: rgba(0, 0, 0, 0.35);
            color: #fff;
            font-size: 1.4rem;
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: center;
            z-index: 5;
            backdrop-filter: blur(6px);
            -webkit-backdrop-filter: blur(6px);
            transition: transform 0.2s ease, background 0.2s ease;
        }

        .carousel-btn:hover {
            background: rgba(0, 0, 0, 0.5);
            transform: translateY(-50%) scale(1.06);
        }

        .carousel-btn:active {
            transform: translateY(-50%) scale(0.98);
        }

        .prev-btn { left: 0; }
        .next-btn { right: 0; }

        .carousel-dots {
            display: flex;
            justify-content: center;
            gap: 0.6rem;
            margin-top: 1.25rem;
            flex-wrap: wrap;
        }

        .carousel-dot {
            width: 10px;
            height: 10px;
            border-radius: 999px;
            border: 2px solid var(--accent-brown);
            background: transparent;
            cursor: pointer;
            padding: 0;
            transition: all 0.2s ease;
        }

        .carousel-dot.active {
            width: 26px;
            background: var(--accent-brown);
        }

        .screenshot-image {
            outline: none;
        }

        .screenshot-image:focus-visible img {
            outline: 3px solid var(--accent-blue);
            outline-offset: 4px;
        }

        /* ==================== 模态框 ==================== */
        .modal {
            display: none;
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(0, 0, 0, 0.86);
            z-index: 2000;
            justify-content: center;
            align-items: center;
            padding: 2rem 1rem;
        }

        .modal.active {
            display: flex;
        }

        .modal-content {
            max-width: 92vw;
            max-height: 92vh;
            position: relative;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            animation: modalZoom 0.3s ease;
        }

        @keyframes modalZoom {
            from { transform: scale(0.8); opacity: 0; }
            to { transform: scale(1); opacity: 1; }
        }

        .modal img {
            max-width: 90vw;
            max-height: 80vh;
            width: auto;
            height: auto;
            object-fit: contain;
            border-radius: 12px;
            box-shadow: 0 10px 50px rgba(0, 0, 0, 0.5);
            display: block;
        }

        .modal-caption {
            margin-top: 0.75rem;
            text-align: center;
            color: rgba(255, 255, 255, 0.9);
            font-size: 1rem;
            line-height: 1.6;
            font-weight: 500;
        }

        .modal-close {
            position: fixed;
            top: 20px;
            right: 20px;
            color: white;
            font-size: 1.8rem;
            cursor: pointer;
            background: var(--accent-brown);
            width: 44px;
            height: 44px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            transition: transform 0.3s ease, background 0.3s ease;
            border: none;
            z-index: 2010;
            box-shadow: 0 4px 12px rgba(0,0,0,0.3);
        }

        .modal-close:hover {
            transform: scale(1.1);
            background: var(--accent-orange, #d4895b);
        }
        
        /* ==================== 模态框导航按钮 ==================== */
        .modal-nav {
            position: fixed;
            top: 50%;
            transform: translateY(-50%);
            background: rgba(255, 255, 255, 0.18);
            color: white;
            border: none;
            width: 50px;
            height: 50px;
            border-radius: 50%;
            font-size: 1.5rem;
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: center;
            transition: all 0.3s ease;
            z-index: 2010;
            backdrop-filter: blur(8px);
            -webkit-backdrop-filter: blur(8px);
        }
        .modal-nav:hover {
            background: rgba(255, 255, 255, 0.35);
            transform: translateY(-50%) scale(1.1);
        }
        .modal-prev { left: 24px; }
        .modal-next { right: 24px; }

        /* ==================== 技术栈 ==================== */
        .tech-section {
            background: var(--paper-cream);
        }

        .tech-grid {
            max-width: 1200px;
            margin: 0 auto;
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
            gap: clamp(1.25rem, 2vw, 2rem);
        }

        .tech-tag {
            background: var(--paper-white);
            border: 2px dashed var(--accent-brown);
            border-radius: 10px;
            padding: 1.5rem 2rem;
            display: flex;
            align-items: center;
            gap: 1.25rem;
            transition: all 0.4s ease;
        }

        .tech-tag:hover {
            transform: translateX(10px);
            border-style: solid;
            box-shadow: 5px 5px 0 var(--accent-orange);
        }

        .tech-icon {
            width: 55px;
            height: 55px;
            background: var(--paper-yellow);
            border: 2px solid var(--accent-brown);
            border-radius: 10px;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.6rem;
            flex-shrink: 0;
            transform: rotate(-5deg);
            transition: transform 0.3s ease;
        }

        .tech-tag:hover .tech-icon {
            transform: rotate(0deg) scale(1.1);
            transform: scale(1.1);
        }

        .tech-info h4 {
            font-size: 1.2rem;
            font-weight: 600;
            color: var(--ink-dark);
            margin-bottom: 0.4rem;
        }

        .tech-info p {
            font-size: 0.95rem;
            color: var(--ink-light);
        }

        /* ==================== 下载区域 ==================== */
        .download-section {
            background: linear-gradient(135deg, var(--paper-blue) 0%, var(--paper-green) 100%);
        }

        .download-container {
            display: grid;
            grid-template-columns: repeat(2, 1fr);
            gap: clamp(1rem, 2vw, 2rem);
            max-width: 900px;
            margin: 0 auto;
        }

        .download-card {
            background: var(--paper-white);
            padding: clamp(2rem, 3vw, 3rem) clamp(1.25rem, 2.5vw, 2rem);
            border-radius: 16px;
            border: 3px solid var(--accent-brown);
            box-shadow: 6px 6px 0 var(--shadow-hard);
            text-align: center;
            transition: all 0.3s ease;
            position: relative;
            overflow: visible; /* allow icon svgs to render without being clipped */
        }

        .download-card::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            height: 4px;
            background: linear-gradient(90deg, var(--accent-brown), var(--accent-orange));
        }

        .download-card:hover {
            transform: translateY(-8px);
            box-shadow: 10px 10px 0 var(--shadow-hard);
        }

        .download-icon {
            margin-bottom: 1.5rem;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            width: 64px;
            height: 64px;
            color: var(--accent-brown);
            overflow: visible; /* avoid clipping inside parent */
        }

        .download-icon svg {
            display: block;
            width: 100%;
            height: 100%;
        }

        .download-title {
            font-size: 1.8rem;
            font-weight: 700;
            color: var(--ink-dark);
            margin-bottom: 1rem;
        }

        .download-description {
            color: var(--ink-medium);
            line-height: 1.6;
            margin-bottom: 2rem;
            font-size: 1rem;
        }

        .btn-download {
            display: inline-block;
            padding: 1rem 2.5rem;
            background: var(--accent-brown);
            color: var(--paper-white);
            text-decoration: none;
            border-radius: 8px;
            font-weight: 600;
            font-size: 1.1rem;
            box-shadow: 4px 4px 0 var(--shadow-hard);
            transition: all 0.2s ease;
        }

        .btn-download:hover {
            transform: translate(2px, 2px);
            box-shadow: 2px 2px 0 var(--shadow-hard);
        }

        /* .download-note removed per design: small line under download cards no longer needed */

        /* 官方徽章样式 */
        .official-badge {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            height: 44px; /* tighter to avoid bottom gap */
            transition: all 0.3s ease;
            border-radius: 8px;
            overflow: hidden;
            box-shadow: 0 2px 8px var(--shadow-soft);
            background: var(--paper-white);
            padding: 0; /* remove extra white space */
            text-decoration: none;
            color: inherit;
        }

        .official-badge:hover {
            transform: translateY(-4px);
            box-shadow: 0 6px 16px var(--shadow-medium);
        }

        .official-badge img {
            display: block;
            max-height: 100%;
            width: auto;
            object-fit: contain;
        }

        .official-badge--github {
            background: #181717;
            color: #ffffff;
            gap: 0.75rem;
            padding: 0 1.5rem;
        }

        .official-badge--github:hover {
            color: #ffffff;
        }

        .official-badge--github .badge-icon {
            display: flex;
            align-items: center;
        }

        .official-badge--github svg {
            width: 22px;
            height: 22px;
            fill: currentColor;
        }

        .official-badge--github .badge-label {
            font-size: 0.9rem;
            font-weight: 700;
            letter-spacing: 0.08em;
            text-transform: uppercase;
        }

        .official-badge--github .badge-text {
            font-size: 0.9rem;
            font-weight: 500;
            white-space: nowrap;
        }

        /* ==================== 快速开始 ==================== */
        .quickstart-section {
            background: var(--paper-white);
        }

        .quickstart-container {
            max-width: 900px;
            margin: 0 auto;
        }

        .quickstart-steps {
            background: var(--paper-cream);
            border: 3px solid var(--accent-brown);
            border-radius: 15px;
            padding: 3rem;
            box-shadow: 8px 8px 0 var(--paper-yellow);
            margin-top: 3rem;
        }

        .step {
            margin-bottom: 2.5rem;
            padding-bottom: 2.5rem;
            border-bottom: 2px dashed var(--line-color);
        }

        .step:last-child {
            margin-bottom: 0;
            padding-bottom: 0;
            border-bottom: none;
        }

        .step h3 {
            font-size: 1.5rem;
            color: var(--ink-dark);
            margin-bottom: 1rem;
            display: flex;
            align-items: center;
            gap: 1rem;
            font-family: 'ZCOOL XiaoWei', serif;
        }

        .step-number {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            width: 40px;
            height: 40px;
            background: var(--accent-brown);
            color: white;
            border-radius: 50%;
            font-weight: 700;
        }

        .step p {
            color: var(--ink-medium);
            line-height: 1.8;
            margin-bottom: 1rem;
        }

        .step pre {
            background: var(--ink-dark);
            color: var(--paper-white);
            padding: 1.25rem 1.5rem;
            border-radius: 8px;
            overflow-x: auto;
            font-size: 0.95rem;
            line-height: 1.6;
        }
        
        /* ==================== 代码块复制按钮 ==================== */
        .code-wrapper {
            position: relative;
        }
        
        .copy-btn {
            position: absolute;
            top: 10px;
            right: 10px;
            background: rgba(255, 255, 255, 0.15);
            border: 1px solid rgba(255, 255, 255, 0.2);
            color: var(--paper-white);
            padding: 4px 8px;
            border-radius: 4px;
            font-size: 0.8rem;
            cursor: pointer;
            transition: all 0.2s;
        }
        .copy-btn:hover { background: rgba(255, 255, 255, 0.25); }
        .copy-btn.copied {
            background: var(--accent-green);
            border-color: var(--accent-green);
        }

        /* ==================== 路线图 ==================== */
        .roadmap-section {
            background: var(--paper-cream);
        }

        .roadmap-container {
            max-width: 1400px;
            margin: 0 auto;
            display: grid;
            grid-template-columns: repeat(2, 1fr);
            gap: clamp(1.25rem, 2vw, 2.5rem);
            margin-top: 3rem;
        }

        .roadmap-card {
            background: var(--paper-white);
            border: 3px solid var(--accent-brown);
            border-radius: 15px;
            padding: clamp(1.75rem, 2.5vw, 2.5rem) clamp(1.25rem, 2vw, 2rem);
            position: relative;
            box-shadow: 6px 6px 0 var(--paper-yellow);
            transition: all 0.4s ease;
        }

        .roadmap-card:hover {
            transform: translateY(-10px);
            box-shadow: 10px 10px 0 var(--paper-yellow);
        }

        .roadmap-card::before {
            content: '';
            position: absolute;
            top: -14px;
            right: 25px;
            width: 45px;
            height: 28px;
            border: 3px solid var(--accent-brown);
            border-bottom: none;
            border-radius: 25px 25px 0 0;
        }

        .roadmap-header {
            display: flex;
            align-items: center;
            gap: 1rem;
            margin-bottom: 2rem;
            padding-bottom: 1.5rem;
            border-bottom: 2px dashed var(--line-color);
        }

        .roadmap-icon {
            font-size: 2.2rem;
        }

        .roadmap-title {
            font-size: 1.5rem;
            font-weight: 700;
            color: var(--ink-dark);
            font-family: 'ZCOOL XiaoWei', serif;
        }

        .roadmap-items {
            list-style: none;
        }

        .roadmap-items li {
            padding: 0.8rem 0;
            color: var(--ink-medium);
            border-bottom: 1px solid var(--line-color);
            display: flex;
            gap: 0.7rem;
            line-height: 1.6;
        }

        .roadmap-items li:last-child {
            border-bottom: none;
        }

        .roadmap-items li::before {
            content: '•';
            color: var(--accent-brown);
            font-size: 1.4rem;
            font-weight: bold;
        }

        /* ==================== FAQ ==================== */
        .faq-section {
            background: var(--paper-white);
        }

        .faq-grid {
            max-width: 1000px;
            margin: 0 auto;
            display: grid;
            gap: 1.25rem;
        }

        .faq-item {
            background: var(--paper-cream);
            border: 2px solid var(--line-color);
            border-radius: 14px;
            box-shadow: 0 6px 16px var(--shadow-soft);
            overflow: hidden;
            transition: border-color 0.25s ease, box-shadow 0.25s ease;
        }

        .faq-item:hover {
            border-color: var(--accent-brown);
            box-shadow: 0 10px 26px var(--shadow-soft);
        }

        .faq-question {
            width: 100%;
            text-align: left;
            background: transparent;
            border: none;
            padding: 1.25rem 1.25rem;
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 1rem;
            color: var(--ink-dark);
            font-weight: 700;
            font-size: 1.05rem;
        }

        .faq-question::after {
            content: '＋';
            flex-shrink: 0;
            color: var(--accent-brown);
            font-size: 1.25rem;
            transition: transform 0.2s ease;
        }

        .faq-question[aria-expanded="true"]::after {
            content: '－';
        }

        .faq-answer {
            padding: 0 1.25rem 1.25rem;
            color: var(--ink-medium);
            line-height: 1.9;
        }

        /* ==================== CTA ==================== */
        .cta-section {
            padding: 5rem 2rem;
            background: var(--accent-brown);
            position: relative;
            overflow: hidden;
        }

        .cta-section::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            height: 25px;
            background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 1200 25'%3E%3Cpath d='M0,12 Q15,0 30,12 T60,12 T90,12 T120,12 T150,12 T180,12 T210,12 T240,12 T270,12 T300,12 T330,12 T360,12 T390,12 T420,12 T450,12 T480,12 T510,12 T540,12 T570,12 T600,12 T630,12 T660,12 T690,12 T720,12 T750,12 T780,12 T810,12 T840,12 T870,12 T900,12 T930,12 T960,12 T990,12 T1020,12 T1050,12 T1080,12 T1110,12 T1140,12 T1170,12 T1200,12 L1200,25 L0,25 Z' fill='%23f9f6f0'/%3E%3C/svg%3E");
            background-size: cover;
        }

        .cta-content {
            max-width: 900px;
            margin: 0 auto;
            text-align: center;
            padding-top: 2rem;
        }

        .cta-content h2 {
            font-size: 3.2rem;
            font-weight: 700;
            color: var(--paper-white);
            margin-bottom: 2rem;
            font-family: 'ZCOOL XiaoWei', serif;
        }

        .cta-content p {
            font-size: 1.35rem;
            color: var(--paper-cream);
            margin-bottom: 2.5rem;
            line-height: 2;
        }

        .btn-cta {
            padding: 1.2rem 3.5rem;
            background: var(--paper-white);
            color: var(--accent-brown);
            border: none;
            border-radius: 12px;
            font-weight: 700;
            font-size: 1.3rem;
            cursor: pointer;
            text-decoration: none;
            display: inline-block;
            box-shadow: 6px 6px 0 var(--shadow-hard);
            transition: all 0.2s ease;
        }

        .btn-cta:hover {
            transform: translate(3px, 3px);
            box-shadow: 3px 3px 0 var(--shadow-hard);
        }

        /* ==================== Footer ==================== */
        footer {
            background: var(--paper-white);
            border-top: 4px solid var(--accent-brown);
            padding: 4rem 2rem 2.5rem;
        }

        .footer-container {
            max-width: 1400px;
            margin: 0 auto;
        }

        .footer-grid {
            display: grid;
            grid-template-columns: 2fr 1fr 1fr 1fr;
            gap: 4rem;
            margin-bottom: 3rem;
        }

        .footer-brand h3 {
            font-size: 2rem;
            font-weight: 700;
            color: var(--accent-brown);
            margin-bottom: 1.5rem;
            font-family: 'ZCOOL XiaoWei', serif;
        }

        .footer-brand p {
            color: var(--ink-light);
            line-height: 2;
            margin-bottom: 1.5rem;
        }

        .social-links {
            display: flex;
            gap: 1rem;
        }

        .social-link {
            width: 45px;
            height: 45px;
            background: var(--paper-yellow);
            border: 2px solid var(--accent-brown);
            border-radius: 10px;
            display: flex;
            align-items: center;
            justify-content: center;
            text-decoration: none;
            font-size: 1.3rem;
            transition: all 0.3s ease;
            transform: rotate(-3deg);
            overflow: visible; /* ensure svg isn't clipped */
        }

        .social-link:hover {
            transform: rotate(3deg) scale(1.15);
            transform: scale(1.15);
            box-shadow: 4px 4px 8px var(--shadow-medium);
        }

        .social-link svg {
            width: 24px;
            height: 24px;
            display: block;
        }

        .footer-section h4 {
            font-size: 1.15rem;
            font-weight: 700;
            color: var(--ink-dark);
            margin-bottom: 1.2rem;
            font-family: 'ZCOOL XiaoWei', serif;
        }

        .footer-links {
            list-style: none;
        }

        .footer-links li {
            margin-bottom: 0.7rem;
        }

        .footer-links a {
            color: var(--ink-medium);
            text-decoration: none;
            transition: all 0.3s ease;
            display: inline-block;
        }

        .footer-links a:hover {
            color: var(--accent-brown);
            transform: translateX(5px);
        }

        .footer-bottom {
            padding-top: 2.5rem;
            border-top: 2px dashed var(--line-color);
            text-align: center;
            color: var(--ink-light);
        }

        /* ==================== 回到顶部按钮 ==================== */
        .back-to-top {
            position: fixed;
            bottom: 30px;
            right: 30px;
            width: 50px;
            height: 50px;
            background: var(--accent-brown);
            color: var(--paper-white);
            border: none;
            border-radius: 50%;
            font-size: 1.5rem;
            cursor: pointer;
            box-shadow: 0 4px 12px var(--shadow-medium);
            opacity: 0;
            visibility: hidden;
            transform: translateY(20px);
            transition: all 0.3s ease;
            z-index: 900;
            display: flex;
            align-items: center;
            justify-content: center;
        }

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

        .back-to-top:hover {
            background: var(--accent-orange);
            transform: translateY(-5px);
            box-shadow: 0 6px 16px var(--shadow-medium);
        }

        /* ==================== 下滑提示箭头 ==================== */
        .scroll-indicator {
            position: absolute;
            bottom: 20px;
            left: 50%;
            transform: translateX(-50%);
            color: var(--ink-light);
            font-size: 2rem;
            animation: bounce 2s infinite;
            cursor: pointer;
            opacity: 0.6;
            transition: opacity 0.3s ease;
        }
        .scroll-indicator:hover { opacity: 1; color: var(--accent-brown); }
        @keyframes bounce {
            0%, 20%, 50%, 80%, 100% { transform: translateX(-50%) translateY(0); }
            40% { transform: translateX(-50%) translateY(-10px); }
            60% { transform: translateX(-50%) translateY(-5px); }
        }

        /* ==================== 响应式 ==================== */
        @media (max-width: 1024px) {
            .hero-container {
                gap: clamp(2rem, 3vw, 3.5rem);
            }
            .hero h1 {
                font-size: clamp(2.5rem, 4.5vw, 3.2rem);
            }
            .footer-grid {
                grid-template-columns: 1fr 1fr;
            }
            .screenshots-grid {
                grid-template-columns: repeat(2, 1fr);
            }
            .arrow-doodle {
                display: none;
            }
        }

        /* 中小屏幕（iPad 竖屏及中屏平板）Hero 布局折叠为单列 */
        @media (max-width: 900px) {
            .hero-container {
                grid-template-columns: 1fr;
                gap: clamp(2.5rem, 4vw, 3.5rem);
            }
        }

        /* 语言切换 */
        html.lang-zh .content-en,
        html.lang-zh .content-ja,
        html.lang-zh .content-ko,
        html.lang-en .content-zh,
        html.lang-en .content-ja,
        html.lang-en .content-ko,
        html.lang-ja .content-zh,
        html.lang-ja .content-en,
        html.lang-ja .content-ko,
        html.lang-ko .content-zh,
        html.lang-ko .content-en,
        html.lang-ko .content-ja,
        body.lang-zh .content-en,
        body.lang-zh .content-ja,
        body.lang-zh .content-ko,
        body.lang-en .content-zh,
        body.lang-en .content-ja,
        body.lang-en .content-ko,
        body.lang-ja .content-zh,
        body.lang-ja .content-en,
        body.lang-ja .content-ko,
        body.lang-ko .content-zh,
        body.lang-ko .content-en,
        body.lang-ko .content-ja {
            display: none !important;
        }

        body.modal-open {
            overflow: hidden;
        }

        /* 微软商店徽章高分辨率样式（小号） */
        ms-store-badge {
          height: 44px !important;
          width: auto !important;
          max-width: 100%;
          display: block;
          margin: 0 auto;
          background: transparent;
          box-shadow: none;
        }

        /* 导航栏滚动隐藏效果 */
        nav {
            transition: transform 0.3s ease;
        }

        /* ---- 平板及中等屏幕：导航链接收进汉堡菜单 ---- */
        @media (max-width: 1240px) {
            .nav-links {
                display: none;
                position: fixed;
                top: var(--mobile-nav-h, 62px);
                left: 0;
                right: 0;
                max-height: calc(100vh - var(--mobile-nav-h, 62px));
                overflow-y: auto;
                background: var(--paper-white);
                flex-direction: column;
                padding: 1.25rem 1.5rem;
                gap: 0;
                border-bottom: 3px solid var(--accent-brown);
                box-shadow: 0 8px 24px var(--shadow-medium);
                z-index: 999;
            }
            .nav-links.active {
                display: flex;
            }
            .nav-links a {
                padding: 0.9rem 0.5rem;
                border-bottom: 1px solid var(--line-color);
                display: block;
                font-size: 1.05rem;
            }
            .nav-links a::after {
                content: none;
            }
            .mobile-nav-dl {
                display: block;
            }
            .mobile-nav-dl a {
                font-weight: 700;
                color: var(--accent-brown) !important;
            }
            .mobile-menu-btn {
                display: flex;
            }
            .mobile-menu-overlay {
                display: block;
                position: fixed;
                top: var(--mobile-nav-h, 62px);
                left: 0;
                right: 0;
                bottom: 0;
                background: rgba(44, 36, 22, 0.45);
                backdrop-filter: blur(4px);
                z-index: 998;
                opacity: 0;
                pointer-events: none;
                transition: opacity 0.3s ease;
            }
            .mobile-menu-overlay.active {
                opacity: 1;
                pointer-events: auto;
            }
            .btn-notebook {
                padding: 0.55rem 1.1rem;
                font-size: 0.9rem;
            }
        }

        /* 屏幕宽度 <= 880px 时隐藏顶部导航栏的独立下载按钮，避免与主题、语言、汉堡按钮堆叠挤出屏幕 */
        @media (max-width: 880px) {
            .nav-actions .btn-notebook {
                display: none !important;
            }
        }

        /* ---- 移动端响应式 (手机端自适应，<= 720px) ---- */
        @media (max-width: 720px) {
            .nav-container {
                padding: 0.6rem clamp(0.5rem, 2.5vw, 1rem);
                gap: 0.5rem;
            }

            .nav-brand {
                gap: 0.4rem;
                min-width: 0;
                flex-shrink: 1;
            }

            .nav-title {
                font-size: clamp(1.05rem, 3.8vw, 1.3rem);
            }

            body.lang-en .nav-title,
            body.lang-ja .nav-title,
            body.lang-ko .nav-title,
            html.lang-en .nav-title,
            html.lang-ja .nav-title,
            html.lang-ko .nav-title {
                font-size: clamp(0.95rem, 3.2vw, 1.15rem);
            }

            .nav-logo {
                width: 32px;
                height: 32px;
            }

            .nav-logo img {
                width: 32px;
                height: 32px;
            }

            .nav-actions {
                position: relative;
                z-index: 1001;
                gap: 0.35rem;
                flex-shrink: 0;
            }

            .theme-toggle {
                width: 36px;
                height: 36px;
                min-width: 36px;
                font-size: 1rem;
            }

            .lang-toggle {
                width: 36px;
                height: 36px;
                min-width: 36px;
                font-size: 1rem;
            }

            .lang-dropdown {
                top: calc(100% + 4px);
                right: 0;
                min-width: 110px;
                padding: 4px;
            }

            .lang-option {
                padding: 6px 8px;
                font-size: 0.82rem;
            }

            .mobile-menu-btn {
                width: 36px;
                height: 36px;
                min-width: 36px;
                font-size: 1.2rem;
            }

            .hero {
                padding: 5.5rem 1.5rem 3rem;
            }
            .hero-container {
                grid-template-columns: 1fr;
                gap: 3rem;
            }
            .hero-content {
                order: 1;
                text-align: left;
            }
            .hero-notebook {
                order: 2;
            }
            .hero h1 {
                font-size: 2.5rem;
            }
            .hero-subtitle {
                font-size: 1.1rem;
            }
            .section-title {
                font-size: 2.5rem;
            }
            .footer-grid {
                grid-template-columns: 1fr;
            }
            .features-grid,
            .screenshots-grid,
            .tech-grid,
            .roadmap-container,
            .download-container {
                grid-template-columns: 1fr;
            }
            .download-card {
                padding: 2.5rem 2rem;
            }
            .download-container {
                gap: 1.5rem;
            }
            .download-icon {
                font-size: 3rem;
            }
            .download-title {
                font-size: 1.5rem;
            }
            /* 移动端轮播适配：隐藏按钮，优化空间，统一布局顺序 */
            .carousel-container { padding: 0.5rem 0.75rem 1.5rem; }
            .carousel-btn { display: none; }
            .carousel-slide { padding: 0.25rem 0.5rem; }
            .screenshot-item {
                grid-template-columns: 1fr;
                gap: 1.25rem;
                max-width: 100%;
                margin: 0.25rem auto 1.5rem;
                padding: 1.5rem 1.25rem;
            }
            .screenshot-image {
                order: 1;
                max-width: 220px;
                margin: 0 auto;
            }
            .screenshot-content {
                order: 2;
                text-align: center;
                padding: 0;
            }
            .screenshot-content h4 {
                font-size: 1.35rem;
                margin-bottom: 0.5rem;
            }
            .screenshot-content p {
                font-size: 0.95rem;
                line-height: 1.6;
                margin-bottom: 0;
            }
            .screenshot-image img {
                max-height: 420px;
            }
            .modal-prev { left: 10px; width: 40px; height: 40px; font-size: 1.2rem; }
            .modal-next { right: 10px; width: 40px; height: 40px; font-size: 1.2rem; }
            .modal-close { top: 12px; right: 12px; width: 38px; height: 38px; font-size: 1.5rem; }
            
            .arrow-doodle {
                display: none;
            }
            .cta-content h2 {
                font-size: 2rem;
            }
            .cta-content p {
                font-size: 1.1rem;
            }
        }

        /* ---- 超窄屏手机进一步自适应 ---- */
        @media (max-width: 520px) {
            .nav-container {
                padding: 0.5rem 0.65rem;
            }
            .nav-title {
                font-size: 1.12rem;
            }
            body.lang-en .nav-title,
            body.lang-ja .nav-title,
            body.lang-ko .nav-title,
            html.lang-en .nav-title,
            html.lang-ja .nav-title,
            html.lang-ko .nav-title {
                font-size: 1.02rem;
            }
        }

        @media (max-width: 380px) {
            .nav-container {
                padding: 0.45rem 0.5rem;
                gap: 0.35rem;
            }
            .nav-logo {
                width: 28px;
                height: 28px;
            }
            .nav-logo img {
                width: 28px;
                height: 28px;
            }
            .nav-title {
                font-size: 0.98rem;
            }
            body.lang-en .nav-title,
            body.lang-ja .nav-title,
            body.lang-ko .nav-title,
            html.lang-en .nav-title,
            html.lang-ja .nav-title,
            html.lang-ko .nav-title {
                font-size: 0.88rem;
            }
            .theme-toggle,
            .lang-toggle,
            .mobile-menu-btn {
                width: 32px;
                height: 32px;
                min-width: 32px;
                font-size: 0.9rem;
            }
        }

        .fade-in {
            opacity: 0;
            transform: translateY(40px);
            transition: opacity 0.8s ease, transform 0.8s ease;
        }

        .fade-in.visible {
            opacity: 1;
            transform: translateY(0);
        }

/* ThoughtEcho Refined Design - 2026 */

/* ==================== 1. Core Variables & Typography ==================== */
:root {
    /* Palette: "Old Library" - Warmer, deeper, more textured */
    --paper-base: #fdfbf7;
    --paper-texture: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noiseFilter'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.8' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noiseFilter)' opacity='0.04'/%3E%3C/svg%3E");
    
    --ink-primary: #2c241b;      /* Softer black, warm charcoal */
    --ink-secondary: #5e5040;    /* Muted brown-grey */
    --ink-tertiary: #8c7b6d;     /* Light stone */
    
    /* Accents: "Natural Ink" */
    --accent-gold: #c7a06f;      /* Aged paper gold */
    --accent-blue: #4a7a94;      /* Faded fountain pen blue */
    --accent-red: #bf5b5b;       /* Red seal ink */
    --accent-green: #6c8c6e;     /* Botanical illustration green */
    
    /* Functional */
    --radius-sm: 8px;
    --radius-md: 16px;
    --radius-lg: 24px;
    --shadow-paper: 
        0 2px 4px rgba(44, 36, 27, 0.04), 
        0 8px 16px rgba(44, 36, 27, 0.06);
    --shadow-float:
        0 12px 24px rgba(44, 36, 27, 0.08),
        0 24px 48px rgba(44, 36, 27, 0.04);
        
    --font-serif: 'Noto Serif SC', 'Noto Serif', serif;
    --font-sans: 'Noto Sans SC', 'Noto Sans', sans-serif;
    --font-hand: 'Caveat', cursive;
}

[data-theme="dark"] {
    --paper-base: #1e1b18;
    --paper-texture: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noiseFilter'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.8' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noiseFilter)' opacity='0.05'/%3E%3C/svg%3E");
    
    --ink-primary: #e6e0d8;
    --ink-secondary: #beb3a6;
    --ink-tertiary: #8f8476;
    
    --accent-gold: #d4b488;
    --accent-blue: #7baec9;
    --accent-red: #d98585;
    --accent-green: #9cc19e;
    
    --shadow-paper: 0 4px 12px rgba(0,0,0,0.3);
}

/* ==================== 2. Base Reset & Layout ==================== */
* { margin: 0; padding: 0; box-sizing: border-box; }
img { max-width: 100%; height: auto; }
html { scroll-behavior: smooth; }

body {
    background-color: var(--paper-base);
    background-image: var(--paper-texture);
    color: var(--ink-primary);
    font-family: var(--font-sans);
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 {
    font-family: var(--font-serif);
    font-weight: 700;
    line-height: 1.2;
    letter-spacing: -0.02em;
}

/* ==================== 3. Enhanced Components ==================== */

/* Hero Section - padding inherited from main .hero rule */

.hero h1 {
    font-size: clamp(2.5rem, 5vw, 4.5rem);
    margin-bottom: 1.5rem;
    background: linear-gradient(135deg, var(--ink-primary) 0%, var(--ink-secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* Paper Cards (Feature & Screenshots) */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    max-width: 1200px;
    margin: 4rem auto;
    padding: 0 2rem;
}

.paper-card {
    background: var(--paper-base);
    border: 1px solid rgba(0,0,0,0.05);
    border-radius: var(--radius-md);
    padding: 2rem;
    box-shadow: var(--shadow-paper);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    position: relative;
}

.paper-card::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0; height: 4px;
    background: var(--accent-gold);
    border-radius: var(--radius-md) var(--radius-md) 0 0;
    opacity: 0.5;
}

.paper-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-float);
}

.paper-card h3 {
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    color: var(--ink-primary);
}

.paper-card .icon {
    font-size: 1.5rem;
    background: rgba(199, 160, 111, 0.15);
    padding: 0.5rem;
    border-radius: 50%;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.8rem 2rem;
    border-radius: 50px;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.2s ease;
}

.btn-primary {
    background: var(--ink-primary);
    color: var(--paper-base);
    box-shadow: 0 4px 12px rgba(44, 36, 27, 0.2);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 16px rgba(44, 36, 27, 0.3);
}

.btn-secondary {
    background: transparent;
    border: 2px solid var(--ink-primary);
    color: var(--ink-primary);
}

.btn-secondary:hover {
    background: rgba(44, 36, 27, 0.05);
}

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.fade-in {
    animation: fadeIn 0.8s ease-out forwards;
}

/* Utilities */
.text-gradient {
    background: linear-gradient(135deg, var(--accent-blue), var(--accent-green));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* Additional Refinements for ThoughtEcho */

/* 1. Improved Typography Scale */
h1 { font-size: 3.5rem; letter-spacing: -0.03em; margin-bottom: 0.5em; }
h2 { font-size: 2.5rem; letter-spacing: -0.02em; margin-bottom: 0.75em; }
h3 { font-size: 1.75rem; font-weight: 600; margin-bottom: 0.5em; }
p { font-size: 1.125rem; line-height: 1.8; color: var(--ink-secondary); margin-bottom: 1.5em; }

/* 2. Hero Section Refinements */
.hero-content {
    max-width: 800px;
    margin: 0 auto;
    position: relative;
    z-index: 2;
}

.hero-tag {
    display: inline-block;
    padding: 0.5rem 1rem;
    border-radius: 50px;
    background: rgba(199, 160, 111, 0.15);
    color: var(--ink-primary);
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    backdrop-filter: blur(4px);
    border: 1px solid rgba(199, 160, 111, 0.2);
}

/* 3. Notebook Visuals */
.notebook-page {
    background: #fff;
    box-shadow: 
        0 0 0 1px rgba(0,0,0,0.03),
        0 10px 30px rgba(0,0,0,0.08),
        0 20px 60px rgba(0,0,0,0.04);
    border-radius: 4px; /* Slightly rounded like real paper */
    position: relative;
}

.notebook-page::before {
    /* Subtle paper texture overlay */
    content: "";
    position: absolute;
    inset: 0;
    background-image: var(--paper-texture);
    opacity: 0.6;
    pointer-events: none;
    z-index: 1;
}

/* 4. Screenshot Carousel Refinements */
.screenshot-item {
    border-radius: 18px;
}

/* 5. Feature Icons */
.feature-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    display: inline-block;
    filter: drop-shadow(0 4px 6px rgba(0,0,0,0.1));
}

/* 6. Footer Refinement */
footer {
    border-top: 1px solid rgba(0,0,0,0.08);
    background: rgba(255,255,255,0.4);
    padding: 4rem 2rem;
    margin-top: 6rem;
}