/* ===================================
   全局样式和变量
   =================================== */
:root {
    /* 品牌色 */
    --primary-color: #20D2D9;
    --secondary-color: #2BBEB3;
    --gradient-primary: linear-gradient(135deg, #20D2D9 0%, #2BBEB3 100%);

    /* 背景色 */
    --bg-dark: #0a0e27;
    --bg-darker: #060816;
    --bg-card: rgba(255, 255, 255, 0.05);
    --bg-light: #f5f3f0;

    /* 文字色 */
    --text-primary: #ffffff;
    --text-secondary: #b8bcc8;
    --text-dark: #2c3e50;

    /* 其他颜色 */
    --border-color: rgba(255, 255, 255, 0.1);
    --shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
    --shadow-hover: 0 15px 50px rgba(32, 210, 217, 0.2);

    /* 间距 */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 6rem;

    /* 字体 */
    --font-primary: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif;
}

/* ===================================
   重置和基础样式
   =================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-primary);
    background: var(--bg-dark);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

a {
    color: inherit;
    text-decoration: none;
    transition: all 0.3s ease;
}

ul {
    list-style: none;
}

/* ===================================
   容器
   =================================== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* ===================================
   导航栏
   =================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(10, 14, 39, 0.9);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    transition: all 0.3s ease;
}

.navbar.scrolled {
    background: rgba(10, 14, 39, 0.95);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

.nav-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.25rem;
    font-weight: 600;
}

.logo img {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    object-fit: cover;
}

.nav-links {
    display: flex;
    gap: 2rem;
    align-items: center;
}

.nav-links a {
    position: relative;
    padding: 0.5rem 0;
    font-weight: 500;
    color: var(--text-secondary);
}

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

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

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

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
}

.mobile-menu-btn span {
    width: 25px;
    height: 2px;
    background: var(--text-primary);
    transition: all 0.3s ease;
}

.mobile-menu {
    position: fixed;
    top: 70px;
    left: 0;
    right: 0;
    background: rgba(10, 14, 39, 0.98);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    padding: 2rem;
    transform: translateY(-100%);
    opacity: 0;
    transition: all 0.3s ease;
    z-index: 999;
}

.mobile-menu.active {
    transform: translateY(0);
    opacity: 1;
}

.mobile-menu ul {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.mobile-menu a {
    display: block;
    padding: 0.5rem;
    font-size: 1.1rem;
    color: var(--text-secondary);
}

.mobile-menu a:hover {
    color: var(--primary-color);
}

/* ===================================
   Hero 区域
   =================================== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    padding-top: 70px;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(circle at 20% 50%, rgba(32, 210, 217, 0.15) 0%, transparent 50%),
                radial-gradient(circle at 80% 80%, rgba(43, 190, 179, 0.15) 0%, transparent 50%),
                var(--bg-darker);
    z-index: -1;
}

.hero-background::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image:
        linear-gradient(rgba(255, 255, 255, 0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 255, 255, 0.03) 1px, transparent 1px);
    background-size: 50px 50px;
    animation: grid-move 20s linear infinite;
}

@keyframes grid-move {
    0% {
        transform: translate(0, 0);
    }
    100% {
        transform: translate(50px, 50px);
    }
}

.hero-content {
    text-align: center;
    z-index: 1;
    animation: fadeInUp 1s ease-out;
}

.hero-title {
    font-size: 4rem;
    font-weight: 700;
    margin-bottom: 1rem;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: gradient-shift 3s ease infinite;
}

@keyframes gradient-shift {
    0%, 100% {
        background-position: 0% 50%;
    }
    50% {
        background-position: 100% 50%;
    }
}

.hero-subtitle {
    font-size: 1.5rem;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.hero-description {
    font-size: 1.25rem;
    color: var(--primary-color);
    margin: 2rem 0;
    font-weight: 500;
}

.hero-buttons {
    display: flex;
    gap: 1.5rem;
    justify-content: center;
    margin-top: 3rem;
}

.btn {
    display: inline-block;
    padding: 1rem 2.5rem;
    border-radius: 50px;
    font-weight: 600;
    font-size: 1.1rem;
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.btn-primary {
    background: var(--gradient-primary);
    color: white;
    box-shadow: 0 5px 20px rgba(32, 210, 217, 0.3);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 30px rgba(32, 210, 217, 0.5);
}

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

.btn-secondary:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-3px);
}

.scroll-indicator {
    position: absolute;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    animation: bounce 2s infinite;
}

.scroll-arrow {
    width: 30px;
    height: 50px;
    border: 2px solid var(--primary-color);
    border-radius: 20px;
    position: relative;
}

.scroll-arrow::after {
    content: '';
    position: absolute;
    top: 10px;
    left: 50%;
    transform: translateX(-50%);
    width: 6px;
    height: 6px;
    background: var(--primary-color);
    border-radius: 50%;
    animation: scroll-dot 2s infinite;
}

@keyframes bounce {
    0%, 100% {
        transform: translateX(-50%) translateY(0);
    }
    50% {
        transform: translateX(-50%) translateY(-10px);
    }
}

@keyframes scroll-dot {
    0% {
        top: 10px;
        opacity: 1;
    }
    100% {
        top: 30px;
        opacity: 0;
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ===================================
   通用区域样式
   =================================== */
section {
    padding: var(--spacing-xl) 0;
    position: relative;
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-lg);
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.title-underline {
    width: 80px;
    height: 4px;
    background: var(--gradient-primary);
    margin: 0 auto 1rem;
    border-radius: 2px;
}

.section-description {
    font-size: 1.2rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* ===================================
   应用介绍
   =================================== */
.about {
    background: linear-gradient(180deg, var(--bg-dark) 0%, var(--bg-darker) 100%);
}

.about-content {
    max-width: 1000px;
    margin: 0 auto;
}

.about-intro {
    text-align: center;
    margin-bottom: 3rem;
}

.intro-text {
    font-size: 1.6rem;
    color: var(--primary-color);
    font-weight: 600;
    line-height: 1.6;
    margin: 0;
}

.about-description-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 3rem 2.5rem;
    margin: 3rem auto;
    max-width: 700px;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    transition: all 0.3s ease;
}

.about-description-card:hover {
    border-color: rgba(32, 210, 217, 0.4);
    box-shadow: 0 10px 40px rgba(32, 210, 217, 0.1);
}

.description-icon {
    font-size: 3rem;
    filter: drop-shadow(0 4px 12px rgba(32, 210, 217, 0.4));
    animation: float 3s ease-in-out infinite;
}

.description-text {
    font-size: 1.3rem;
    color: var(--text-secondary);
    line-height: 1.9;
    text-align: center;
    margin: 0;
}

.about-cta-box {
    position: relative;
    text-align: center;
    padding: 4rem 3rem;
    margin: 4rem auto 2rem;
    max-width: 800px;
    background: linear-gradient(135deg, rgba(32, 210, 217, 0.05) 0%, rgba(43, 190, 179, 0.05) 100%);
    border: 2px solid rgba(32, 210, 217, 0.2);
    border-radius: 25px;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    overflow: hidden;
}

.about-cta-box::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(32, 210, 217, 0.08) 0%, transparent 70%);
    animation: pulse-slow 8s ease-in-out infinite;
}

@keyframes pulse-slow {
    0%, 100% {
        transform: scale(1);
        opacity: 0.5;
    }
    50% {
        transform: scale(1.1);
        opacity: 0.8;
    }
}

.cta-decoration {
    font-size: 2.5rem;
    margin-bottom: 1.5rem;
    filter: drop-shadow(0 4px 12px rgba(32, 210, 217, 0.5));
    animation: twinkle 2s ease-in-out infinite;
}

@keyframes twinkle {
    0%, 100% {
        opacity: 1;
        transform: scale(1);
    }
    50% {
        opacity: 0.7;
        transform: scale(1.1);
    }
}

.cta-title {
    font-size: 1.4rem;
    color: var(--text-primary);
    font-weight: 500;
    margin-bottom: 1rem;
    position: relative;
    z-index: 1;
}

.cta-subtitle {
    font-size: 1.2rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    line-height: 1.7;
    position: relative;
    z-index: 1;
}

.cta-highlight {
    position: relative;
    z-index: 1;
    display: inline-block;
    padding: 1rem 2.5rem;
    background: var(--gradient-primary);
    border-radius: 50px;
    box-shadow: 0 8px 25px rgba(32, 210, 217, 0.3);
    transition: all 0.3s ease;
}

.cta-highlight:hover {
    transform: translateY(-3px);
    box-shadow: 0 12px 35px rgba(32, 210, 217, 0.5);
}

.highlight-text {
    font-size: 1.4rem;
    font-weight: 600;
    color: white;
    letter-spacing: 0.5px;
}

.features-compact {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
    margin: 3rem 0;
}

.feature-compact-item {
    display: flex;
    align-items: flex-start;
    gap: 1.25rem;
    padding: 1.75rem;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    transition: all 0.3s ease;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

.feature-compact-item:hover {
    transform: translateY(-5px);
    border-color: rgba(32, 210, 217, 0.5);
    box-shadow: 0 8px 25px rgba(32, 210, 217, 0.15);
}

.feature-compact-icon {
    font-size: 2.25rem;
    flex-shrink: 0;
    line-height: 1;
    filter: drop-shadow(0 2px 8px rgba(32, 210, 217, 0.3));
}

.feature-compact-content h4 {
    color: var(--text-primary);
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    line-height: 1.4;
}

.feature-compact-content p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.6;
    margin: 0;
}

.privacy-note {
    display: flex;
    align-items: flex-start;
    gap: 1.5rem;
    background: linear-gradient(135deg, rgba(32, 210, 217, 0.08) 0%, rgba(43, 190, 179, 0.08) 100%);
    border: 1px solid rgba(32, 210, 217, 0.2);
    border-radius: 20px;
    padding: 2.5rem;
    margin: 3rem 0;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

.privacy-icon {
    font-size: 2.5rem;
    flex-shrink: 0;
    filter: drop-shadow(0 2px 8px rgba(32, 210, 217, 0.4));
}

.privacy-content h3 {
    color: var(--primary-color);
    font-size: 1.3rem;
    margin: 0 0 0.75rem 0;
    font-weight: 600;
}

.privacy-content p {
    color: var(--text-secondary);
    font-size: 1rem;
    line-height: 1.7;
    margin: 0;
}

/* ===================================
   产品特色
   =================================== */
.features {
    background: var(--bg-darker);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: var(--spacing-lg);
}

.feature-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 2.5rem;
    transition: all 0.3s ease;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

.feature-card:hover {
    transform: translateY(-10px);
    border-color: var(--primary-color);
    box-shadow: var(--shadow-hover);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: 1.5rem;
    display: inline-block;
    animation: float 3s ease-in-out infinite;
}

.feature-card:nth-child(1) .feature-icon { animation-delay: 0s; }
.feature-card:nth-child(2) .feature-icon { animation-delay: 0.2s; }
.feature-card:nth-child(3) .feature-icon { animation-delay: 0.4s; }
.feature-card:nth-child(4) .feature-icon { animation-delay: 0.6s; }
.feature-card:nth-child(5) .feature-icon { animation-delay: 0.8s; }
.feature-card:nth-child(6) .feature-icon { animation-delay: 1s; }

@keyframes float {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-10px);
    }
}

.feature-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.feature-card p {
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ===================================
   产品展示
   =================================== */
.showcase {
    background: linear-gradient(180deg, var(--bg-darker) 0%, var(--bg-dark) 100%);
}

.showcase-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    margin-top: var(--spacing-lg);
}

.showcase-item {
    position: relative;
    border-radius: 20px;
    overflow: hidden;
    cursor: pointer;
    aspect-ratio: 9/19.5;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
}

.showcase-item:hover {
    transform: translateY(-10px) scale(1.02);
    box-shadow: var(--shadow-hover);
}

.showcase-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s ease;
}

.showcase-item:hover img {
    transform: scale(1.05);
}

.showcase-overlay {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    background: linear-gradient(to top, rgba(0, 0, 0, 0.9) 0%, transparent 100%);
    padding: 2rem 1.5rem;
    transform: translateY(100%);
    transition: transform 0.3s ease;
}

.showcase-item:hover .showcase-overlay {
    transform: translateY(0);
}

.showcase-overlay h3 {
    font-size: 1.2rem;
    margin-bottom: 0.5rem;
    color: var(--primary-color);
}

.showcase-overlay p {
    font-size: 0.95rem;
    color: var(--text-secondary);
}

/* ===================================
   下载区域
   =================================== */
.download {
    background: var(--bg-dark);
    padding: var(--spacing-xl) 0;
    position: relative;
    overflow: hidden;
}

.download::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(32, 210, 217, 0.1) 0%, transparent 70%);
    animation: pulse 4s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% {
        transform: translate(-50%, -50%) scale(1);
        opacity: 1;
    }
    50% {
        transform: translate(-50%, -50%) scale(1.2);
        opacity: 0.5;
    }
}

.download-content {
    text-align: center;
    position: relative;
    z-index: 1;
}

.download-title {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 1rem;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.download-subtitle {
    font-size: 1.5rem;
    color: var(--text-secondary);
    margin-bottom: 3rem;
}

.download-buttons {
    display: flex;
    gap: 2rem;
    justify-content: center;
    flex-wrap: wrap;
}

.download-btn {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem 2rem;
    background: var(--bg-card);
    border: 2px solid var(--border-color);
    border-radius: 15px;
    transition: all 0.3s ease;
    min-width: 200px;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

.download-btn:hover {
    border-color: var(--primary-color);
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

.btn-icon {
    width: 40px;
    height: 40px;
}

.btn-icon svg {
    width: 100%;
    height: 100%;
}

.btn-text {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    text-align: left;
}

.btn-text .small {
    font-size: 0.75rem;
    color: var(--text-secondary);
    text-transform: uppercase;
}

.btn-text .large {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
}

/* ===================================
   联系我们
   =================================== */
.contact {
    background: var(--bg-darker);
}

.contact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    margin-top: var(--spacing-lg);
}

.contact-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 2.5rem;
    text-align: center;
    transition: all 0.3s ease;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

.contact-card:hover {
    transform: translateY(-10px);
    border-color: var(--primary-color);
    box-shadow: var(--shadow-hover);
}

.contact-icon {
    font-size: 3rem;
    margin-bottom: 1.5rem;
}

.contact-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.contact-card p,
.contact-card a {
    color: var(--text-secondary);
    line-height: 1.7;
}

.contact-card a:hover {
    color: var(--primary-color);
}

/* ===================================
   页脚
   =================================== */
.footer {
    background: var(--bg-darker);
    border-top: 1px solid var(--border-color);
    padding: 3rem 0;
}

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

.footer-logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.25rem;
    font-weight: 600;
}

.footer-logo img {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    object-fit: cover;
}

.footer-text {
    text-align: center;
    color: var(--text-secondary);
}

.footer-text p {
    margin-bottom: 0.5rem;
}

.footer-text a {
    color: var(--text-secondary);
    transition: color 0.3s ease;
}

.footer-text a:hover {
    color: var(--primary-color);
}

/* ===================================
   返回顶部按钮
   =================================== */
.back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 50px;
    height: 50px;
    background: var(--gradient-primary);
    border: none;
    border-radius: 50%;
    color: white;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    z-index: 999;
    box-shadow: 0 4px 15px rgba(32, 210, 217, 0.3);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    transform: translateY(-5px);
    box-shadow: 0 6px 20px rgba(32, 210, 217, 0.5);
}

.back-to-top svg {
    width: 24px;
    height: 24px;
}

/* ===================================
   响应式设计
   =================================== */

/* 平板设备 */
@media (max-width: 768px) {
    html {
        font-size: 14px;
    }

    .nav-links {
        display: none;
    }

    .mobile-menu-btn {
        display: flex;
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .hero-subtitle {
        font-size: 1.2rem;
    }

    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }

    .section-title {
        font-size: 2rem;
    }

    .features-grid {
        grid-template-columns: 1fr;
    }

    .features-compact {
        grid-template-columns: 1fr;
    }

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

    .about-description-card {
        padding: 2.5rem 2rem;
    }

    .about-cta-box {
        padding: 3rem 2.5rem;
    }

    .showcase-grid {
        grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    }

    .download-title {
        font-size: 2rem;
    }

    .download-subtitle {
        font-size: 1.2rem;
    }

    .download-buttons {
        flex-direction: column;
        align-items: center;
    }

    .contact-grid {
        grid-template-columns: 1fr;
    }
}

/* 手机设备 */
@media (max-width: 480px) {
    :root {
        --spacing-xl: 3rem;
        --spacing-lg: 2rem;
    }

    .container {
        padding: 0 var(--spacing-sm);
    }

    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .hero-description {
        font-size: 1rem;
    }

    .btn {
        padding: 0.75rem 1.5rem;
        font-size: 1rem;
    }

    .section-title {
        font-size: 1.5rem;
    }

    .intro-text {
        font-size: 1.25rem;
    }

    .about-description-card {
        padding: 2rem 1.5rem;
        margin: 2rem auto;
    }

    .description-icon {
        font-size: 2.5rem;
    }

    .description-text {
        font-size: 1.1rem;
    }

    .about-cta-box {
        padding: 3rem 2rem;
        margin: 3rem auto 1.5rem;
    }

    .cta-decoration {
        font-size: 2rem;
    }

    .cta-title {
        font-size: 1.2rem;
    }

    .cta-subtitle {
        font-size: 1.05rem;
    }

    .highlight-text {
        font-size: 1.2rem;
    }

    .feature-compact-item {
        padding: 1.25rem;
    }

    .feature-compact-icon {
        font-size: 1.75rem;
    }

    .privacy-note {
        padding: 1.5rem;
    }

    .privacy-icon {
        font-size: 2rem;
    }

    .feature-card,
    .contact-card {
        padding: 1.5rem;
    }

    .showcase-grid {
        grid-template-columns: 1fr;
    }

    .download-btn {
        min-width: 100%;
    }

    .back-to-top {
        bottom: 1rem;
        right: 1rem;
        width: 45px;
        height: 45px;
    }
}

/* 大屏幕优化 */
@media (min-width: 1600px) {
    .container {
        max-width: 1400px;
    }

    .hero-title {
        font-size: 5rem;
    }

    .section-title {
        font-size: 3rem;
    }
}