/* Threads Reply Official Website Styles */

/* CSS Variables */
:root {
    --primary-color: #4FC3F7;
    --secondary-color: #1A237E;
    --accent-color: #4DB6AC;
    --text-color: #333333;
    --text-light: #666666;
    --background-color: #FFFFFF;
    --background-alt: #F5F9FC;
    --border-color: #E0E0E0;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 4px 16px rgba(0, 0, 0, 0.15);
    --radius: 12px;
    --radius-sm: 8px;
    --transition: all 0.3s ease;
}

/* Reset & Base */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--background-color);
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: var(--transition);
}

a:hover {
    color: var(--secondary-color);
}

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

/* Container */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
.header {
    position: sticky;
    top: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    z-index: 100;
}

.header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 20px;
}

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

.logo img {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-sm);
}

.logo span {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--secondary-color);
}

.nav {
    display: flex;
    align-items: center;
    gap: 24px;
}

.nav a {
    color: var(--text-color);
    font-weight: 500;
}

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

.lang-switcher {
    display: flex;
    gap: 8px;
}

.lang-switcher button {
    background: none;
    border: 1px solid var(--border-color);
    padding: 4px 12px;
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-size: 0.875rem;
    transition: var(--transition);
}

.lang-switcher button:hover,
.lang-switcher button.active {
    background: var(--primary-color);
    border-color: var(--primary-color);
    color: white;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--background-alt) 0%, #E3F2FD 100%);
    padding: 80px 0;
    text-align: center;
}

.hero-content {
    max-width: 600px;
    margin: 0 auto;
}

.hero-icon {
    width: 120px;
    height: 120px;
    border-radius: 24px;
    box-shadow: var(--shadow-lg);
    margin-bottom: 32px;
}

.hero h1 {
    font-size: 2.5rem;
    color: var(--secondary-color);
    margin-bottom: 16px;
    line-height: 1.3;
}

.hero p {
    font-size: 1.25rem;
    color: var(--text-light);
    margin-bottom: 32px;
}

.app-store-btn {
    display: inline-block;
    transition: var(--transition);
}

.app-store-btn:hover {
    transform: scale(1.05);
}

.app-store-btn img {
    height: 54px;
}

.ios-badge {
    display: inline-block;
    margin-top: 16px;
    padding: 8px 16px;
    background: var(--secondary-color);
    color: white;
    font-size: 0.875rem;
    border-radius: var(--radius-sm);
}

/* Features Section */
.features {
    padding: 80px 0;
}

.section-title {
    text-align: center;
    font-size: 2rem;
    color: var(--secondary-color);
    margin-bottom: 48px;
}

.features-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 24px;
}

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

.feature-card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px);
}

.feature-icon {
    width: 64px;
    height: 64px;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
    font-size: 28px;
}

.feature-card h3 {
    font-size: 1.25rem;
    color: var(--secondary-color);
    margin-bottom: 12px;
}

.feature-card p {
    color: var(--text-light);
    font-size: 0.95rem;
}

/* Pricing Section */
.pricing {
    background: var(--background-alt);
    padding: 80px 0;
}

.pricing-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 24px;
    max-width: 800px;
    margin: 0 auto;
}

.pricing-card {
    background: white;
    border-radius: var(--radius);
    padding: 40px 32px;
    text-align: center;
    border: 2px solid var(--border-color);
    transition: var(--transition);
}

.pricing-card.featured {
    border-color: var(--primary-color);
    box-shadow: var(--shadow-lg);
}

.pricing-badge {
    display: inline-block;
    background: var(--primary-color);
    color: white;
    font-size: 0.75rem;
    font-weight: 600;
    padding: 4px 12px;
    border-radius: 20px;
    margin-bottom: 16px;
    text-transform: uppercase;
}

.pricing-card h3 {
    font-size: 1.5rem;
    color: var(--secondary-color);
    margin-bottom: 8px;
}

.pricing-price {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 24px;
}

.pricing-price span {
    font-size: 1rem;
    font-weight: 400;
    color: var(--text-light);
}

.pricing-features {
    list-style: none;
    margin-bottom: 32px;
}

.pricing-features li {
    padding: 12px 0;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-light);
}

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

.pricing-features li::before {
    content: "✓";
    color: var(--accent-color);
    font-weight: bold;
    margin-right: 8px;
}

/* Footer */
.footer {
    background: var(--secondary-color);
    color: white;
    padding: 48px 0 24px;
}

.footer-content {
    display: grid;
    grid-template-columns: 1fr;
    gap: 32px;
    margin-bottom: 32px;
}

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

.footer-brand .logo {
    justify-content: center;
    margin-bottom: 12px;
}

.footer-brand .logo span {
    color: white;
}

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

.footer-links h4 {
    font-size: 1rem;
    margin-bottom: 16px;
    opacity: 0.8;
}

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

.footer-links li {
    margin-bottom: 8px;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.8);
}

.footer-links a:hover {
    color: white;
}

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

.footer-contact h4 {
    font-size: 1rem;
    margin-bottom: 16px;
    opacity: 0.8;
}

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

.footer-bottom {
    text-align: center;
    padding-top: 24px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    font-size: 0.875rem;
    opacity: 0.7;
}

/* Legal Pages */
.legal-page {
    padding: 48px 0 80px;
}

.legal-page .container {
    max-width: 800px;
}

.legal-page h1 {
    font-size: 2rem;
    color: var(--secondary-color);
    margin-bottom: 8px;
}

.legal-page .last-updated {
    color: var(--text-light);
    font-size: 0.875rem;
    margin-bottom: 32px;
}

.legal-page h2 {
    font-size: 1.5rem;
    color: var(--secondary-color);
    margin-top: 40px;
    margin-bottom: 16px;
    padding-bottom: 8px;
    border-bottom: 2px solid var(--border-color);
}

.legal-page h3 {
    font-size: 1.125rem;
    color: var(--text-color);
    margin-top: 24px;
    margin-bottom: 12px;
}

.legal-page p {
    margin-bottom: 16px;
    color: var(--text-light);
}

.legal-page ul, .legal-page ol {
    margin-bottom: 16px;
    padding-left: 24px;
    color: var(--text-light);
}

.legal-page li {
    margin-bottom: 8px;
}

.legal-page strong {
    color: var(--text-color);
}

/* Responsive */
@media (min-width: 640px) {
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .pricing-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .footer-content {
        grid-template-columns: repeat(3, 1fr);
        text-align: left;
    }

    .footer-brand,
    .footer-links,
    .footer-contact {
        text-align: left;
    }

    .footer-brand .logo {
        justify-content: flex-start;
    }
}

@media (min-width: 1024px) {
    .hero h1 {
        font-size: 3rem;
    }

    .features-grid {
        grid-template-columns: repeat(4, 1fr);
    }

    .feature-card {
        padding: 40px 24px;
    }
}

/* Language visibility - Default: show Chinese, hide English */
.en {
    display: none;
}

/* When English is active: show English, hide Chinese */
[lang="en"] .zh {
    display: none !important;
}
[lang="en"] .en {
    display: revert !important;
}

/* Mobile menu toggle */
.menu-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    padding: 8px;
}

@media (max-width: 639px) {
    .menu-toggle {
        display: block;
    }

    .nav {
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: 16px;
        border-bottom: 1px solid var(--border-color);
        display: none;
    }

    .nav.active {
        display: flex;
    }

    .lang-switcher {
        position: absolute;
        right: 60px;
        top: 50%;
        transform: translateY(-50%);
    }
}