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

:root {
    --primary-color: #007AFF;
    --secondary-color: #5856D6;
    --success-color: #34C759;
    --warning-color: #FF9500;
    --danger-color: #FF3B30;
    --text-primary: #1D1D1F;
    --text-secondary: #6E6E73;
    --bg-light: #F5F5F7;
    --bg-white: #FFFFFF;
    --border-color: #D2D2D7;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 4px 16px rgba(0, 0, 0, 0.15);
    --border-radius: 12px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-white);
}

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

/* Navigation Bar */
.navbar {
    background-color: var(--bg-white);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
    padding: 1rem 0;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 2rem;
}

.nav-brand h1 {
    font-size: 1.5rem;
    color: var(--primary-color);
    font-weight: 600;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-menu a {
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 500;
    transition: color 0.3s ease;
    padding: 0.5rem 1rem;
    border-radius: 8px;
}

.nav-menu a:hover {
    color: var(--primary-color);
    background-color: var(--bg-light);
}

.nav-menu a.active {
    color: var(--primary-color);
    background-color: var(--bg-light);
}

/* Language Switcher */
.language-switcher {
    margin-left: auto;
}

.language-links {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.lang-link {
    padding: 0.4rem 0.8rem;
    color: var(--text-primary);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    border-radius: 6px;
    transition: all 0.3s ease;
}

.lang-link:hover {
    color: var(--primary-color);
    background-color: var(--bg-light);
}

.lang-link.active {
    color: var(--primary-color);
    background-color: var(--bg-light);
}

.lang-separator {
    color: var(--border-color);
    margin: 0 0.2rem;
}

.language-select {
    padding: 0.5rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    background-color: var(--bg-white);
    color: var(--text-primary);
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    font-family: inherit;
}

.language-select:hover {
    border-color: var(--primary-color);
    background-color: var(--bg-light);
}

.language-select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(0, 122, 255, 0.1);
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 5rem 0;
    text-align: center;
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.hero-subtitle {
    font-size: 1.75rem;
    margin-bottom: 0.5rem;
    opacity: 0.95;
}

.hero-description {
    font-size: 1.25rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

/* Mac App Store Badge */
.appstore-badge {
    display: inline-flex;
    align-items: center;
    text-decoration: none;
    line-height: 0;
    transition: transform 0.25s ease, filter 0.25s ease;
}

.appstore-badge:hover {
    transform: translateY(-2px);
    filter: drop-shadow(0 14px 28px rgba(0, 0, 0, 0.28));
}

.appstore-badge:focus-visible {
    outline: 3px solid rgba(255, 255, 255, 0.65);
    outline-offset: 4px;
}

.appstore-badge__img {
    /* Match the visual height of .btn (padding + line-height) */
    height: 54px;
    width: auto;
    display: block;
}

@media (max-width: 480px) {
    .appstore-badge__img {
        height: 48px;
    }
}

/* Default to English; switch to Chinese when i18n sets lang=zh-CN */
.appstore-badge__img--zh {
    display: none;
}

html[lang="zh-CN"] .appstore-badge__img--en {
    display: none;
}

html[lang="zh-CN"] .appstore-badge__img--zh {
    display: block;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.875rem 2rem;
    border-radius: var(--border-radius);
    text-decoration: none;
    font-weight: 600;
    font-size: 1rem;
    transition: all 0.3s ease;
    cursor: pointer;
    border: none;
}

.btn-primary {
    background-color: var(--bg-white);
    color: var(--primary-color);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
}

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

.btn-secondary:hover {
    background-color: var(--bg-white);
    color: var(--primary-color);
}

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

.btn-outline:hover {
    background-color: var(--primary-color);
    color: var(--bg-white);
}

/* Section Titles */
.section-title {
    font-size: 2.5rem;
    text-align: center;
    margin-bottom: 3rem;
    font-weight: 700;
    color: var(--text-primary);
}

/* Features Section */
.features {
    padding: 5rem 0;
    background-color: var(--bg-light);
}

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

.feature-card {
    background-color: var(--bg-white);
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

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

.feature-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

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

.feature-card p {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

/* Privacy Highlight Section */
.privacy-highlight {
    padding: 5rem 0;
    background-color: var(--bg-white);
}

.privacy-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.privacy-text {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    line-height: 1.8;
}

.privacy-list {
    text-align: left;
    list-style: none;
    margin-bottom: 2rem;
}

.privacy-list li {
    padding: 1rem;
    margin-bottom: 1rem;
    background-color: var(--bg-light);
    border-radius: 8px;
    font-size: 1rem;
}

.privacy-list li strong {
    color: var(--primary-color);
}

/* CTA Section */
.cta {
    padding: 5rem 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
}

.cta h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.cta p {
    font-size: 1.25rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.cta-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

/* Page Header */
.page-header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 3rem 0;
    text-align: center;
}

.page-header h1 {
    font-size: 3rem;
    margin-bottom: 0.5rem;
}

.page-header p {
    font-size: 1.25rem;
    opacity: 0.9;
}

.update-date {
    font-size: 1rem !important;
    opacity: 0.8 !important;
    margin-top: 0.5rem;
}

/* Support Content */
.support-content {
    padding: 4rem 0;
    background-color: var(--bg-white);
}

.support-section {
    max-width: 900px;
    margin: 0 auto 4rem;
}

.support-section h2 {
    font-size: 2rem;
    margin-bottom: 2rem;
    color: var(--text-primary);
}

.faq-item {
    background-color: var(--bg-light);
    padding: 2rem;
    border-radius: var(--border-radius);
    margin-bottom: 1.5rem;
}

.faq-item h3 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.faq-item p {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.faq-item ul {
    margin-left: 1.5rem;
    color: var(--text-secondary);
}

.faq-item ul li {
    margin-bottom: 0.5rem;
}

.requirements {
    background-color: var(--bg-light);
    padding: 2rem;
    border-radius: var(--border-radius);
}

.requirements ul {
    list-style: none;
}

.requirements li {
    padding: 0.75rem 0;
    color: var(--text-secondary);
    border-bottom: 1px solid var(--border-color);
}

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

.contact-info {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin: 2rem 0;
}

.contact-item {
    display: flex;
    gap: 1rem;
    align-items: flex-start;
    padding: 1.5rem;
    background-color: var(--bg-light);
    border-radius: var(--border-radius);
}

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

.contact-details h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.contact-details p {
    color: var(--text-secondary);
}

.response-time {
    text-align: center;
    color: var(--text-secondary);
    font-style: italic;
    margin-top: 1rem;
}

.troubleshooting-item {
    background-color: var(--bg-light);
    padding: 2rem;
    border-radius: var(--border-radius);
    margin-bottom: 1.5rem;
}

.troubleshooting-item h3 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.troubleshooting-item p {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.troubleshooting-item ol {
    margin-left: 1.5rem;
    color: var(--text-secondary);
}

.troubleshooting-item ol li {
    margin-bottom: 0.5rem;
}

.help-center {
    text-align: center;
}

.help-links {
    display: flex;
    gap: 2rem;
    justify-content: center;
    margin-top: 2rem;
    flex-wrap: wrap;
}

.help-link {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    padding: 1.5rem;
    background-color: var(--bg-light);
    border-radius: var(--border-radius);
    text-decoration: none;
    color: var(--text-primary);
    transition: all 0.3s ease;
    min-width: 150px;
}

.help-link:hover {
    background-color: var(--primary-color);
    color: var(--bg-white);
    transform: translateY(-3px);
    box-shadow: var(--shadow-hover);
}

.help-link span:first-child {
    font-size: 2rem;
}

/* Privacy Policy */
.privacy-policy {
    padding: 4rem 0;
    background-color: var(--bg-white);
}

.policy-content {
    max-width: 900px;
    margin: 0 auto;
}

.policy-section {
    margin-bottom: 3rem;
}

.policy-section h2 {
    font-size: 1.75rem;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
    border-bottom: 2px solid var(--primary-color);
    padding-bottom: 0.5rem;
}

.policy-section h3 {
    font-size: 1.25rem;
    margin: 1.5rem 0 1rem;
    color: var(--text-primary);
}

.policy-section p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
    line-height: 1.8;
}

.policy-section ul {
    margin-left: 1.5rem;
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

.policy-section li {
    margin-bottom: 0.75rem;
    line-height: 1.8;
}

.policy-section strong {
    color: var(--text-primary);
}

.summary-box {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 3rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-hover);
}

.summary-box h2 {
    color: white;
    border-bottom: 2px solid rgba(255, 255, 255, 0.3);
}

.summary-box p,
.summary-box ul,
.summary-box li,
.summary-box strong {
    color: white;
}

.summary-intro {
    font-size: 1.25rem;
    margin-bottom: 1.5rem;
}

.summary-list {
    list-style: none;
    margin-left: 0;
}

.summary-list li {
    padding: 0.75rem 0;
    font-size: 1.1rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.2);
}

.summary-list li:last-child {
    border-bottom: none;
}

.summary-note {
    margin-top: 2rem;
    font-size: 1.1rem;
    padding-top: 1.5rem;
    border-top: 1px solid rgba(255, 255, 255, 0.3);
}

/* Footer */
.footer {
    background-color: var(--text-primary);
    color: var(--bg-light);
    padding: 2rem 0;
    margin-top: 4rem;
}

.footer-content {
    text-align: center;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-bottom: 1rem;
    flex-wrap: wrap;
}

.footer-links a {
    color: var(--bg-light);
    text-decoration: none;
    transition: color 0.3s ease;
}

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

.footer-copyright {
    font-size: 0.875rem;
    opacity: 0.7;
}

/* Responsive Design */
@media (max-width: 768px) {
    .hero-title {
        font-size: 2.5rem;
    }

    .hero-subtitle {
        font-size: 1.25rem;
    }

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

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

    .page-header h1 {
        font-size: 2rem;
    }

    .nav-menu {
        gap: 1rem;
    }

    .nav-menu a {
        padding: 0.5rem;
        font-size: 0.9rem;
    }

    .language-select {
        font-size: 0.8rem;
        padding: 0.4rem 0.6rem;
    }

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

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

    .btn {
        width: 100%;
        max-width: 300px;
    }

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

    .help-links {
        flex-direction: column;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }

    .hero {
        padding: 3rem 0;
    }

    .features,
    .privacy-highlight,
    .cta {
        padding: 3rem 0;
    }

    .nav-brand h1 {
        font-size: 1.2rem;
    }
}