/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #007AFF;
    --secondary-color: #34C759;
    --accent-color: #FF9500;
    --text-primary: #1D1D1F;
    --text-secondary: #86868B;
    --background-primary: #FFFFFF;
    --background-secondary: #F5F5F7;
    --border-color: #D2D2D7;
    --shadow-light: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-medium: 0 4px 16px rgba(0, 0, 0, 0.15);
    --border-radius: 12px;
    --transition: all 0.3s ease;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--background-primary);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header and Navigation */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    transition: var(--transition);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-weight: 600;
    font-size: 1.25rem;
    color: var(--text-primary);
    text-decoration: none;
}

.logo-img {
    width: 40px;
    height: 40px;
    border-radius: 8px;
    object-fit: cover;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 32px;
}

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    position: relative;
}

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

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: var(--transition);
}

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

.language-toggle {
    background: var(--background-secondary);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 8px 16px;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
}

.language-toggle:hover {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

/* Hero Section */
.hero {
    padding: 120px 0 80px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grain" width="100" height="100" patternUnits="userSpaceOnUse"><circle cx="50" cy="50" r="1" fill="white" opacity="0.1"/></pattern></defs><rect width="100" height="100" fill="url(%23grain)"/></svg>');
    opacity: 0.3;
}

.hero-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
    position: relative;
    z-index: 1;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 24px;
    background: linear-gradient(45deg, #fff, #f0f0f0);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.25rem;
    line-height: 1.6;
    margin-bottom: 40px;
    opacity: 0.9;
}

.hero-buttons {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 16px 32px;
    border-radius: var(--border-radius);
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
    box-shadow: var(--shadow-medium);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(0, 122, 255, 0.3);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    border: 2px solid rgba(255, 255, 255, 0.3);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

.hero-image {
    display: flex;
    justify-content: center;
    align-items: center;
}

.app-preview {
    width: 300px;
    height: 600px;
    border-radius: 24px;
    object-fit: cover;
    transform: perspective(1000px) rotateY(-15deg) rotateX(5deg);
    transition: var(--transition);
}

.app-preview:hover {
    transform: perspective(1000px) rotateY(-10deg) rotateX(2deg) scale(1.05);
}

/* Features Section */
.features {
    padding: 80px 0;
    background: var(--background-secondary);
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 60px;
    color: var(--text-primary);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 32px;
}

.feature-card {
    background: white;
    padding: 32px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-light);
    transition: var(--transition);
    text-align: center;
}

.feature-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-medium);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: 20px;
}

.feature-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.feature-desc {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* About Section */
.about {
    padding: 80px 0;
    background: white;
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.about-desc {
    font-size: 1.1rem;
    line-height: 1.7;
    color: var(--text-secondary);
    margin-bottom: 24px;
}

.about-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    margin-top: 40px;
}

.stat {
    text-align: center;
    padding: 24px;
    background: var(--background-secondary);
    border-radius: var(--border-radius);
}

.stat-number {
    display: block;
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 8px;
}

.stat-label {
    font-size: 0.9rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.about-img {
    width: 100%;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-medium);
}

/* Download Section */
.download {
    padding: 80px 0;
    background: var(--background-secondary);
}

.download-subtitle {
    text-align: center;
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 60px;
}

.download-options {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
}

.download-card {
    background: white;
    padding: 40px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-light);
    transition: var(--transition);
    text-align: center;
    position: relative;
    overflow: hidden;
}

.download-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    opacity: 0;
    transition: var(--transition);
}

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

.download-card.pwa {
    border: 2px solid rgba(52, 199, 89, 0.2);
    background: linear-gradient(135deg, #ffffff 0%, #f8fff9 100%);
}

.download-card.pwa::before {
    background: linear-gradient(90deg, var(--secondary-color), #2db84d);
}

.download-card.pwa:hover {
    border-color: var(--secondary-color);
    transform: translateY(-8px);
    box-shadow: 0 8px 25px rgba(52, 199, 89, 0.2);
}

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

.platform-icon {
    font-size: 4rem;
    margin-bottom: 24px;
}

.platform-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 16px;
    color: var(--text-primary);
}

.platform-desc {
    color: var(--text-secondary);
    margin-bottom: 24px;
    line-height: 1.6;
}

.platform-features {
    list-style: none;
    margin-bottom: 32px;
    text-align: left;
}

.platform-features li {
    padding: 8px 0;
    color: var(--text-secondary);
    position: relative;
    padding-left: 24px;
}

.platform-features li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--secondary-color);
    font-weight: bold;
}

.btn-ios {
    background: var(--primary-color);
    color: white;
    width: 100%;
    justify-content: center;
    position: relative;
}

/* 二维码弹窗样式 */
.qr-popup {
    position: fixed;
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-medium);
    padding: 20px;
    z-index: 10000;
    opacity: 0;
    visibility: hidden;
    transform: scale(0.8);
    transition: all 0.3s ease;
    border: 1px solid var(--border-color);
    max-width: 280px;
    text-align: center;
}

.qr-popup.show {
    opacity: 1;
    visibility: visible;
    transform: scale(1);
}

.qr-popup img {
    width: 200px;
    height: 200px;
    border-radius: 8px;
    margin-bottom: 12px;
}

.qr-popup .qr-title {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.qr-popup .qr-desc {
    font-size: 12px;
    color: var(--text-secondary);
    line-height: 1.4;
}

/* 二维码弹窗箭头 */
.qr-popup::before {
    content: '';
    position: absolute;
    width: 0;
    height: 0;
    border: 8px solid transparent;
}

.qr-popup.arrow-top::before {
    border-bottom-color: white;
    top: -16px;
    left: 50%;
    transform: translateX(-50%);
}

.qr-popup.arrow-bottom::before {
    border-top-color: white;
    bottom: -16px;
    left: 50%;
    transform: translateX(-50%);
}

.qr-popup.arrow-left::before {
    border-right-color: white;
    left: -16px;
    top: 50%;
    transform: translateY(-50%);
}

.qr-popup.arrow-right::before {
    border-left-color: white;
    right: -16px;
    top: 50%;
    transform: translateY(-50%);
}

.btn-pwa {
    background: var(--secondary-color);
    color: white;
    width: 100%;
    justify-content: center;
    position: relative;
    z-index: 5;
}

.btn-pwa:hover,
.btn-pwa:active {
    background: #2db84d;
    transform: translateY(-1px);
    box-shadow: var(--shadow-medium);
}

.download-note {
    text-align: center;
    padding: 20px;
    background: rgba(255, 149, 0, 0.1);
    border-radius: var(--border-radius);
    border: 1px solid rgba(255, 149, 0, 0.2);
}

.download-note p {
    color: var(--accent-color);
    font-weight: 500;
}

/* How to Use Section */
.how-to-use {
    padding: 80px 0;
    background: white;
}

.steps {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
}

.step {
    text-align: center;
    padding: 32px 24px;
}

.step-number {
    width: 60px;
    height: 60px;
    background: var(--primary-color);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 700;
    margin: 0 auto 24px;
}

.step-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.step-desc {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* Footer */
.footer {
    background: var(--text-primary);
    color: white;
    padding: 60px 0 20px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
}

.footer-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 20px;
}

.footer-text {
    color: rgba(255, 255, 255, 0.8);
    margin-bottom: 8px;
    line-height: 1.6;
    word-wrap: break-word;
    overflow-wrap: break-word;
}

.footer-link {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    display: block;
    margin-bottom: 8px;
    transition: var(--transition);
}

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

.footer-contact-item {
    display: flex;
    align-items: flex-start;
    margin-bottom: 12px;
    flex-wrap: wrap;
    line-height: 1.5;
}

.footer-label {
    color: rgba(255, 255, 255, 0.8);
    margin-right: 8px;
    white-space: nowrap;
    flex-shrink: 0;
    font-size: inherit;
    min-width: 30px;
}

.footer-contact-item .footer-link {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    transition: var(--transition);
    display: inline-block;
    margin-bottom: 0;
    font-size: inherit;
    word-break: break-all;
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.2);
    padding-top: 20px;
    text-align: center;
}

.footer-copyright {
    color: rgba(255, 255, 255, 0.6);
    font-size: 0.9rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-container {
        padding: 0 16px;
        height: 60px;
    }
    
    .logo {
        font-size: 1.1rem;
    }
    
    .logo-img {
        width: 32px;
        height: 32px;
    }
    
    .nav-links {
        gap: 12px;
        font-size: 0.9rem;
    }
    
    .nav-link {
        padding: 8px 4px;
        white-space: nowrap;
    }
    
    .language-toggle {
        padding: 6px 12px;
        font-size: 0.85rem;
    }
    
    .hero-container {
        grid-template-columns: 1fr;
        gap: 40px;
        text-align: center;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-buttons {
        justify-content: center;
    }
    
    .about-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .about-stats {
        grid-template-columns: 1fr;
    }
    
    .download-options {
        grid-template-columns: 1fr;
        gap: 24px;
    }
    
    .download-card {
        padding: 32px 24px;
    }
    
    .steps {
        grid-template-columns: 1fr;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 30px;
    }
    
    .footer-text {
        font-size: 0.9rem;
    }
    
    .footer-contact-item {
        flex-direction: column;
        align-items: flex-start;
        margin-bottom: 16px;
    }
    
    .footer-label {
        margin-right: 0;
        margin-bottom: 4px;
        min-width: auto;
        font-weight: 500;
    }
    
    .footer-contact-item .footer-link {
        margin-left: 0;
        padding: 4px 0;
    }
    
    .app-preview {
        width: 250px;
        height: 500px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }
    
    .nav-container {
        padding: 0 12px;
        height: 56px;
    }
    
    .logo {
        font-size: 1rem;
        gap: 8px;
    }
    
    .logo-img {
        width: 28px;
        height: 28px;
    }
    
    .nav-links {
        gap: 8px;
        font-size: 0.8rem;
    }
    
    .nav-link {
        padding: 6px 2px;
    }
    
    .language-toggle {
        padding: 4px 8px;
        font-size: 0.8rem;
    }
    
    .hero {
        padding: 100px 0 60px;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1.1rem;
    }
    
    .btn {
        padding: 14px 24px;
        font-size: 0.9rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .feature-card,
    .download-card {
        padding: 24px 20px;
    }
    
    .download-options {
        gap: 20px;
    }
    
    .platform-features {
        margin-bottom: 24px;
    }
    
    .platform-features li {
        font-size: 0.9rem;
        padding: 6px 0;
        padding-left: 20px;
    }
    
    .footer-content {
        gap: 20px;
    }
    
    .footer-text {
        font-size: 0.85rem;
    }
    
    .footer-title {
        font-size: 1.1rem;
        margin-bottom: 15px;
    }
    
    .footer-contact-item {
        margin-bottom: 20px;
    }
    
    .footer-label {
        font-size: 0.9rem;
        margin-bottom: 6px;
    }
    
    .footer-contact-item .footer-link {
        font-size: 0.9rem;
        padding: 6px 0;
    }
    
    .app-preview {
        width: 200px;
        height: 400px;
    }
}

/* 特别针对Safari移动端的优化 */
@supports (-webkit-touch-callout: none) {
    .header {
        background: rgba(255, 255, 255, 0.98);
        -webkit-backdrop-filter: blur(20px);
    }
    
    .nav-links {
        -webkit-overflow-scrolling: touch;
    }
    
    .btn {
        -webkit-appearance: none;
        -webkit-tap-highlight-color: transparent;
    }
    
    .download-card {
        -webkit-transform: translateZ(0);
    }
    
    .nav-link {
        -webkit-tap-highlight-color: transparent;
    }
    
    .language-toggle {
        -webkit-appearance: none;
        -webkit-tap-highlight-color: transparent;
    }
}

/* 移动端导航栏优化 */
@media (max-width: 480px) {
    .nav-container {
        position: relative;
    }
    
    .nav-links {
        position: absolute;
        right: 0;
        top: 50%;
        transform: translateY(-50%);
        display: flex;
        align-items: center;
        gap: 6px;
        background: rgba(255, 255, 255, 0.95);
        padding: 4px 8px;
        border-radius: 20px;
        box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    }
    
    .nav-link {
        font-size: 0.75rem;
        padding: 4px 6px;
        border-radius: 12px;
        transition: all 0.2s ease;
    }
    
    .nav-link:hover,
    .nav-link:active {
        background: rgba(0, 122, 255, 0.1);
        color: var(--primary-color);
    }
    
    .language-toggle {
        font-size: 0.75rem;
        padding: 4px 8px;
        border-radius: 12px;
        background: var(--primary-color);
        color: white;
        border: none;
    }
    
    .language-toggle:hover,
    .language-toggle:active {
        background: #0056cc;
    }
}

/* 确保PWA链接在移动端清晰可见 */
@media (max-width: 480px) {
    .btn-pwa {
        background: var(--secondary-color) !important;
        color: white !important;
        font-weight: 600;
        padding: 16px 20px;
        border-radius: var(--border-radius);
        text-decoration: none;
        display: inline-flex !important;
        align-items: center;
        justify-content: center;
        gap: 8px;
        width: 100%;
        margin-top: 8px;
        box-shadow: var(--shadow-light);
        transition: var(--transition);
        position: relative;
        z-index: 10;
        visibility: visible !important;
        opacity: 1 !important;
    }
    
    .btn-pwa:hover,
    .btn-pwa:active {
        background: #2db84d;
        transform: translateY(-1px);
        box-shadow: var(--shadow-medium);
    }
    
    .btn-pwa .btn-icon {
        font-size: 1.1rem;
    }
    
    .btn-pwa .btn-text {
        font-size: 1rem;
        font-weight: 600;
        display: inline-block !important;
    }
    
    .btn-pwa .btn-icon {
        display: inline-block !important;
    }
    
    .download-note {
        margin-top: 20px;
        padding: 16px;
        font-size: 0.9rem;
    }
    
    .download-note p {
        margin: 0;
        line-height: 1.5;
    }
}

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

.feature-card,
.download-card,
.step {
    animation: fadeInUp 0.6s ease-out;
}

/* Smooth scrolling */
html {
    scroll-behavior: smooth;
}

/* Focus styles for accessibility */
.btn:focus,
.nav-link:focus,
.language-toggle:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* 确保PWA按钮在所有情况下都可见 */
.btn-pwa {
    display: inline-flex !important;
    visibility: visible !important;
    opacity: 1 !important;
    position: relative !important;
    z-index: 5 !important;
}

.btn-pwa * {
    display: inline-block !important;
    visibility: visible !important;
}

/* 覆盖任何可能的display: none */
.btn-pwa[style*="display: none"] {
    display: inline-flex !important;
}

.btn-pwa[style*="display:none"] {
    display: inline-flex !important;
}