:root {
    /* 提取自应用的主题背景色：从聊天页面背景图和主题设定分析，应用多使用暖色调/米白色背景 (如 0xFFF5F5F5, 0xFFF5F1EB, 0xFFFEFEFF) */
    --bg-color: #FEFEFF; /* 采用登录页和主色调搭配的米白/纯白背景 */
    --text-color: #333333; /* 文字颜色改为深灰/黑色 */
    --text-muted: #666666; /* 次要文字颜色 */
    --accent-color: #F87E20; /* 应用主题橙色 */
    --input-bg: #F5F5F5;
    --input-border: #E0E0E0;
    --line-color: rgba(248, 126, 32, 0.2); /* 连线使用主题色的淡化版 */

    /* 添加一些卡片背景色和阴影 */
    --card-bg: #FFFFFF;
    --card-shadow: 0 8px 30px rgba(0, 0, 0, 0.08);
}

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

/* 动态背景动画 */
@keyframes gradientBG {
    0% {
        background-position: 0% 50%;
    }
    50% {
        background-position: 100% 50%;
    }
    100% {
        background-position: 0% 50%;
    }
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    /* 使用大面积的动态渐变背景替代纯色 */
    background: linear-gradient(-45deg, #FEFEFF, #FFF5EB, #FEFEFF, #FFF8F0);
    background-size: 400% 400%;
    animation: gradientBG 15s ease infinite;
    color: var(--text-color);
    line-height: 1.5;
    overflow-x: hidden;
}

.section-container {
    max-width: 1200px; /* 增加最大宽度，原为1000px，让内容铺得更开 */
    margin: 0 auto;
    padding-left: 2rem;
    padding-right: 2rem;
}

/* Navbar */
.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem 0;
    max-width: 1200px; /* 导航栏也跟随加宽 */
    margin: 0 auto;
    padding-left: 2rem;
    padding-right: 2rem;
    position: relative;
    z-index: 10;
}

.logo-container {
    display: flex;
    align-items: center;
    gap: 12px;
}

.nav-logo {
    width: 36px;
    height: 36px;
    border-radius: 8px;
    object-fit: contain;
}

.nav-brand {
    font-family: 'Georgia', serif;
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--accent-color);
}

/* Hero Section */
.hero {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 3rem; /* 恢复原来的高度 */
    padding-bottom: 2rem; /* 恢复原来的高度 */
    position: relative;
    z-index: 10;
}

.hero-content {
    flex: 1;
    max-width: 500px; /* 加宽左侧文字区域，原为440px */
}

.title {
    font-size: 2.2rem;
    font-weight: 600;
    line-height: 1.3;
    margin-bottom: 1.5rem;
    letter-spacing: -0.5px;
    color: #111;
}

.description {
    color: var(--text-muted);
    font-size: 1.05rem;
    margin-bottom: 1.5rem; /* 减小描述文字下方的间距 */
    line-height: 1.6;
}

/* Action Area */
.action-area {
    display: flex;
    margin-top: 1rem;
}

.btn-primary {
    display: inline-block;
    background-color: var(--accent-color);
    color: #fff;
    text-decoration: none;
    border: none;
    border-radius: 25px;
    padding: 0.9rem 2rem;
    font-weight: 600;
    font-size: 1.1rem;
    cursor: pointer;
    transition: background-color 0.2s, transform 0.2s, box-shadow 0.2s;
    box-shadow: 0 4px 15px rgba(248, 126, 32, 0.3);
}

.btn-primary:hover {
    background-color: #E65100; /* 更深的橙色，来自源码 Color(0xFFE65100) */
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(248, 126, 32, 0.4);
}

/* Phone Mockup */
.hero-image {
    flex: 1;
    display: flex;
    justify-content: flex-end;
}

.phone-mockup {
    width: 300px;
    height: 620px;
    border: 8px solid #F5F5F5; /* 浅色边框 */
    border-radius: 40px;
    background-color: #FFFFFF;
    position: relative;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 0 0 1px #E0E0E0, var(--card-shadow);
}

.notch {
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 120px;
    height: 25px;
    background-color: #F5F5F5;
    border-bottom-left-radius: 15px;
    border-bottom-right-radius: 15px;
    z-index: 2;
}

.screen-placeholder {
    color: var(--text-color);
    font-size: 0.9rem;
    text-align: center;
    padding: 2rem;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    height: 100%;
    width: 100%;
    /* 使用应用内的浅暖色渐变背景 */
    background: linear-gradient(to bottom, #FFFBF4, #FFE6BF);
}

.screen-logo {
    width: 80px;
    height: 80px;
    border-radius: 16px;
    margin-bottom: 20px;
    box-shadow: 0 4px 12px rgba(248, 126, 32, 0.2);
}

.screen-placeholder h2 {
    font-size: 1.2rem;
    color: var(--accent-color);
    margin-bottom: 1rem;
    line-height: 1.4;
}

.screen-placeholder p {
    color: var(--text-muted);
    font-size: 0.95rem;
    line-height: 1.6;
}

/* Decorative Background Elements */
body {
    position: relative;
}

/* 点阵网格背景 */
.bg-grid {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background-image: radial-gradient(var(--input-border) 1px, transparent 1px); /* 改回1px */
    background-size: 40px 40px; /* 改回40px间距，让它稀疏一点 */
    opacity: 0.4; /* 调低不透明度 */
    z-index: 0;
    pointer-events: none;
}

/* 渐变模糊色块 */
.bg-blobs {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    z-index: 0;
    pointer-events: none;
    overflow: hidden;
}

.bg-blob {
    position: absolute;
    border-radius: 50%;
    filter: blur(120px); /* 增加模糊度，让它更柔和 */
    opacity: 0.15; /* 降低不透明度 */
    animation: float 20s infinite alternate ease-in-out;
}

.blob-1 {
    top: -5%;
    left: -10%;
    width: 50vw;
    height: 50vw;
    max-width: 800px;
    max-height: 800px;
    background-color: #FFE0B2; /* 改为非常柔和的浅橙/香槟色 */
    animation-delay: 0s;
}

.blob-2 {
    bottom: 0%;
    right: -10%;
    width: 45vw;
    height: 45vw;
    max-width: 700px;
    max-height: 700px;
    background-color: #FFCC80; /* 柔和的中等橙色 */
    animation-delay: -5s;
}

.blob-3 {
    top: 30%;
    left: 20%;
    width: 35vw;
    height: 35vw;
    max-width: 600px;
    max-height: 600px;
    background-color: #FFF3E0; /* 极浅的橙色 */
    animation-delay: -10s;
}

/* 漂浮的小形状（圆圈、圆环） */
.floating-shapes {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
    pointer-events: none;
    overflow: hidden;
}

.f-shape {
    position: absolute;
    animation: float-small 15s infinite alternate ease-in-out;
    opacity: 0.3; /* 降低形状的不透明度，让它们成为淡淡的背景点缀 */
}

.f-shape-circle {
    border-radius: 50%;
    background-color: var(--accent-color);
}

.f-shape-ring {
    border-radius: 50%;
    border: 2px solid var(--accent-color); /* 减细边框 */
    background-color: transparent;
}

/* 缩小几何图形的大小，让它们不那么突兀 */
.fs-1 { width: 20px; height: 20px; top: 15%; left: 8%; animation-delay: 0s; }
.fs-2 { width: 45px; height: 45px; top: 25%; right: 12%; animation-delay: -2s; opacity: 0.2; }
.fs-3 { width: 15px; height: 15px; top: 45%; left: 6%; animation-delay: -4s; }
.fs-4 { width: 60px; height: 60px; top: 60%; right: 8%; animation-delay: -6s; opacity: 0.15;}
.fs-5 { width: 30px; height: 30px; top: 80%; left: 10%; animation-delay: -8s; opacity: 0.25;}
.fs-6 { width: 25px; height: 25px; top: 90%; right: 15%; animation-delay: -1s; }

@keyframes float {
    0% { transform: translate(0, 0) scale(1); }
    33% { transform: translate(30px, -50px) scale(1.1); }
    66% { transform: translate(-20px, 20px) scale(0.9); }
    100% { transform: translate(0, 0) scale(1); }
}

@keyframes float-small {
    0% { transform: translateY(0) rotate(0deg); }
    100% { transform: translateY(-40px) rotate(180deg); }
}

/* 暗黑模式适配装饰 */
body.dark-theme .bg-grid {
    background-image: radial-gradient(rgba(255, 255, 255, 0.1) 2px, transparent 2px);
}
body.dark-theme .bg-blob {
    opacity: 0.15;
}
body.dark-theme .f-shape {
    opacity: 0.4;
}

@media (prefers-color-scheme: dark) {
    body:not(.light-theme) .bg-grid {
        background-image: radial-gradient(rgba(255, 255, 255, 0.1) 2px, transparent 2px);
    }
    body:not(.light-theme) .bg-blob {
        opacity: 0.15;
    }
    body:not(.light-theme) .f-shape {
        opacity: 0.4;
    }
}
.feature-section {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 6rem; /* 增加图文之间的间距，原为4rem */
    position: relative;
    z-index: 10;
    margin-top: -30px; /* 减小上方留白 */
    margin-bottom: -30px; /* 减小下方留白 */
}

.feature-section.left-image {
    flex-direction: row;
}

.feature-section.right-image {
    /* HTML中文字已经在图片前面了，所以不需要row-reverse，直接用row即可 */
    flex-direction: row;
}

.feature-text {
    flex: 1;
    max-width: 480px; /* 加宽功能区块文字区域，原为380px */
}

.feature-text h3 {
    font-size: 1.8rem;
    margin-bottom: 0.8rem; /* 减小标题与正文的间距 */
    font-weight: 600;
    color: var(--accent-color);
}

.feature-text p {
    color: var(--text-muted);
    font-size: 1.05rem;
    line-height: 1.7;
}

.feature-image {
    flex: 1;
    display: flex;
    justify-content: center;
}

/* Connectors */
.connector {
    width: 100%;
    height: 250px; /* 恢复原来的连线高度 */
    max-width: 900px; /* 连接线也跟随内容加宽，原800px */
    margin: -50px auto; /* 恢复原来的边距 */
    position: relative;
    z-index: 1;
    opacity: 0.8;
}

.connector svg {
    width: 100%;
    height: 100%;
    overflow: visible;
}

.connector path {
    fill: none;
    stroke: var(--line-color);
    stroke-width: 1.5px;
    vector-effect: non-scaling-stroke;
}

/* Footer */
.footer {
    border-top: 1px solid #EEEEEE;
    background-color: #F8F9FA;
    padding: 3rem 2rem 3rem;
    margin-top: 2rem;
}

.footer-content {
    max-width: 1000px;
    margin: 0 auto;
    display: flex;
    justify-content: center;
    align-items: center;
}

.footer-info {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 1.5rem;
}

.footer-logo {
    width: 48px;
    height: 48px;
    border-radius: 12px;
    filter: none;
    transition: filter 0.3s;
}


.footer-text {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.copyright {
    color: var(--text-muted);
    font-size: 0.9rem;
}

.icp {
    font-size: 0.85rem;
}

.icp a {
    color: #999999;
    text-decoration: none;
    transition: color 0.3s;
}

.icp a:hover {
    color: var(--accent-color);
}

/* Modal Styles */
.modal {
    display: none;
    position: fixed;
    z-index: 100;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    align-items: center;
    justify-content: center;
}

.modal-content {
    background-color: #FEFEFF;
    padding: 2.5rem;
    border-radius: 20px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
    position: relative;
    max-width: 400px;
    width: 90%;
    text-align: center;
}

.close-btn {
    position: absolute;
    top: 15px;
    right: 20px;
    color: #999;
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
    transition: color 0.3s;
}

.close-btn:hover {
    color: #333;
}

.modal-content h3 {
    margin-bottom: 2rem;
    color: var(--text-color);
    font-size: 1.3rem;
}

.download-options {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.btn-option {
    display: block;
    padding: 1rem;
    border-radius: 12px;
    text-decoration: none;
    color: #fff;
    font-weight: 600;
    transition: transform 0.2s, box-shadow 0.2s;
}

.android-btn {
    background-color: #3DDC84; /* Android Green */
}

.ios-btn {
    background-color: #000000; /* Apple Black */
}

.btn-option:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

/* Theme Toggle Button */
.theme-toggle {
    background: transparent;
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    color: var(--text-color);
    transition: background-color 0.2s, color 0.2s;
    margin-left: 20px;
}

.theme-toggle:hover {
    background-color: rgba(0, 0, 0, 0.05);
}

.theme-toggle svg {
    width: 20px;
    height: 20px;
    fill: currentColor;
}

/* 默认隐藏暗色图标 */
.theme-toggle .icon-moon { display: none; }
.theme-toggle .icon-sun { display: block; }

/* 暗色模式下类名的应用 */
body.dark-theme .theme-toggle .icon-sun { display: none; }
body.dark-theme .theme-toggle .icon-moon { display: block; }
body.dark-theme .theme-toggle:hover {
    background-color: rgba(255, 255, 255, 0.1);
}
/* Night Mode / Dark Theme Support */
/* 移除纯媒体查询，改用类名控制，方便手动和系统联动 */
/* 夜间模式适配背景动画 */
body.dark-theme {
    --text-color: #E0E0E0;
    --text-muted: #A0A0A0;
    --input-bg: #1E1E1E;
    --input-border: #333333;
    --line-color: rgba(248, 126, 32, 0.4);
    --card-bg: #1E1E1E;
    --card-shadow: 0 8px 30px rgba(0, 0, 0, 0.5);
    /* 夜间模式的动态渐变 */
    background: linear-gradient(-45deg, #121212, #1A120A, #121212, #1A1410);
    background-size: 400% 400%;
    animation: gradientBG 15s ease infinite;
}

body.dark-theme .title {
    color: #F5F5F5;
}

/* 反转 Logo 颜色，如果 Logo 是深色的，或者在图片上加一点亮度/滤镜 */
body.dark-theme .nav-brand {
    color: var(--accent-color); /* 橙色在暗色下通常表现不错，保留 */
}

body.dark-theme .phone-mockup {
    background-color: #000000;
    border-color: #333333;
    box-shadow: 0 0 0 1px #444444, var(--card-shadow);
}

body.dark-theme .notch {
    background-color: #333333;
}

body.dark-theme .screen-placeholder {
    background: linear-gradient(to bottom, #2C1A0D, #1A0D04); /* 替换为暗暖色渐变，配合橙色主题 */
    color: #E0E0E0;
}

body.dark-theme .footer {
    background-color: #1A1A1A;
    border-top-color: #333333;
}

body.dark-theme .footer-logo {
    /* 如果logo在暗色下看不清，可以加一点白色背景或反转 */
    background-color: rgba(255, 255, 255, 0.1);
    padding: 4px;
}

body.dark-theme .modal-content {
    background-color: var(--card-bg);
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.8);
}

body.dark-theme .close-btn {
    color: #888;
}

body.dark-theme .close-btn:hover {
    color: #DDD;
}

/* 底部引导区域背景适配 */
body.dark-theme .bottom-cta {
    background: linear-gradient(to bottom, transparent, rgba(248, 126, 32, 0.15)) !important;
}

/* 兼容系统的偏好设置 */
@media (prefers-color-scheme: dark) {
    body:not(.light-theme) {
        --text-color: #E0E0E0;
        --text-muted: #A0A0A0;
        --input-bg: #1E1E1E;
        --input-border: #333333;
        --line-color: rgba(248, 126, 32, 0.4);
        --card-bg: #1E1E1E;
        --card-shadow: 0 8px 30px rgba(0, 0, 0, 0.5);
        background: linear-gradient(-45deg, #121212, #1A120A, #121212, #1A1410);
        background-size: 400% 400%;
        animation: gradientBG 15s ease infinite;
    }

    body:not(.light-theme) .title { color: #F5F5F5; }
    body:not(.light-theme) .nav-brand { color: var(--accent-color); }
    body:not(.light-theme) .phone-mockup {
        background-color: #000000;
        border-color: #333333;
        box-shadow: 0 0 0 1px #444444, var(--card-shadow);
    }
    body:not(.light-theme) .notch { background-color: #333333; }
    body:not(.light-theme) .screen-placeholder {
        background: linear-gradient(to bottom, #2C1A0D, #1A0D04);
        color: #E0E0E0;
    }
    body:not(.light-theme) .footer {
        background-color: #1A1A1A;
        border-top-color: #333333;
    }
    body:not(.light-theme) .footer-logo {
        background-color: rgba(255, 255, 255, 0.1);
        padding: 4px;
    }
    body:not(.light-theme) .modal-content {
        background-color: var(--card-bg);
        box-shadow: 0 10px 40px rgba(0, 0, 0, 0.8);
    }
    body:not(.light-theme) .close-btn { color: #888; }
    body:not(.light-theme) .close-btn:hover { color: #DDD; }
    body:not(.light-theme) .bottom-cta {
        background: linear-gradient(to bottom, transparent, rgba(248, 126, 32, 0.15)) !important;
    }

    /* 按钮图标状态同步 */
    body:not(.light-theme) .theme-toggle .icon-sun { display: none; }
    body:not(.light-theme) .theme-toggle .icon-moon { display: block; }
    body:not(.light-theme) .theme-toggle:hover {
        background-color: rgba(255, 255, 255, 0.1);
    }
}
@media (max-width: 768px) {
    .section-container {
        padding-left: 1.5rem;
        padding-right: 1.5rem;
    }

    .navbar {
        padding-left: 1.5rem;
        padding-right: 1.5rem;
    }

    .hero {
        flex-direction: column;
        align-items: center;
        text-align: center;
        padding-top: 2rem;
    }

    .hero-content {
        margin-bottom: 4rem;
        display: flex;
        flex-direction: column;
        align-items: center;
        max-width: 100%;
    }

    .title {
        font-size: 1.8rem;
    }

    .description {
        font-size: 1rem;
    }

    .feature-section.left-image,
    .feature-section.right-image {
        flex-direction: column;
        text-align: center;
        gap: 2.5rem;
        padding-top: 2rem;
        padding-bottom: 2rem;
    }

    .feature-text {
        max-width: 100%;
        margin-bottom: 1rem;
        order: 2;
    }

    .feature-image {
        order: 1;
        width: 100%;
    }

    .phone-mockup {
        width: 280px;
        height: 580px;
    }

    .connector {
        display: none;
    }
}

@media (max-width: 375px) {
    .phone-mockup {
        width: 260px;
        height: 540px;
    }

    .title {
        font-size: 1.6rem;
    }
}