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

:root {
    --primary-color: #667eea;
    --secondary-color: #764ba2;
    --accent-color: #f093fb;
    --text-dark: #2d3748;
    --text-light: #718096;
    --bg-light: #f7fafc;
    --bg-white: #ffffff;
    --border-color: #e2e8f0;
    --success-color: #48bb78;
    --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-accent: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

body {
    font-family: 'Noto Sans KR', 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    overflow-x: hidden;
}

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

/* Language Switcher */
.language-switcher {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 1000;
    display: flex;
    gap: 8px;
    background: var(--bg-white);
    border-radius: 12px;
    padding: 8px;
    box-shadow: var(--shadow-lg);
}

/* Page Top Bar with Logo and Version Switcher */
.page-top-bar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: var(--bg-white);
    padding: 16px 32px;
    box-shadow: var(--shadow-md);
}

.logo-link {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    transition: transform 0.2s ease;
}

.logo-link:hover {
    transform: scale(1.05);
}

/* Version Switcher for Privacy Pages */
.version-switcher {
    display: flex;
    gap: 12px;
    background: var(--bg-light);
    border-radius: 12px;
    padding: 8px;
}

.version-btn {
    background: transparent;
    color: var(--text-dark);
    text-decoration: none;
    padding: 10px 16px;
    border-radius: 12px;
    font-weight: 500;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 8px;
}

.version-btn:hover {
    background: var(--bg-light);
    transform: translateY(-1px);
}

.version-btn.active {
    background: var(--gradient-primary);
    color: white;
    box-shadow: var(--shadow-md);
}

.lang-btn {
    background: transparent;
    border: none;
    padding: 8px 12px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: all 0.2s ease;
}

.lang-btn:hover {
    background: var(--bg-light);
}

.lang-btn.active {
    background: var(--gradient-primary);
    color: white;
}

/* Hero Section */
.hero {
    background: var(--gradient-primary);
    color: white;
    padding: 120px 0 80px;
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url("data:image/svg+xml,%3Csvg width='40' height='40' viewBox='0 0 40 40' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='%23ffffff' fill-opacity='0.05' fill-rule='evenodd'%3E%3Cpath d='m0 40l40-40h-40v40zm40 0v-40h-40l40 40z'/%3E%3C/g%3E%3C/svg%3E");
    opacity: 0.3;
}

.hero .container {
    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;
    margin-bottom: 24px;
    line-height: 1.1;
}

.highlight {
    background: var(--gradient-accent);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

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

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

.download-buttons.center {
    justify-content: center;
}

.download-btn {
    display: flex;
    align-items: center;
    gap: 12px;
    background: var(--bg-white);
    color: var(--text-dark);
    text-decoration: none;
    padding: 16px 24px;
    border-radius: 16px;
    box-shadow: var(--shadow-md);
    transition: all 0.3s ease;
    font-weight: 500;
}

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

.download-btn i {
    font-size: 24px;
}

.download-btn .small {
    display: block;
    font-size: 12px;
    opacity: 0.7;
}

.download-btn .large {
    display: block;
    font-size: 16px;
    font-weight: 600;
}

/* Phone Mockup */
.hero-image {
    display: flex;
    justify-content: center;
    align-items: center;
}

.phone-mockup {
    width: 400px;
    height: 500px;
    position: relative;
    background-image: url('Frame%2062.png?v=1');
    background-size: contain;
    background-repeat: no-repeat;
    background-position: center;
}

.phone-screen {
    display: none;
}

/* Sections */
section {
    padding: 80px 0;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 24px;
    color: var(--text-dark);
}

.section-description {
    font-size: 1.125rem;
    text-align: center;
    color: var(--text-light);
    max-width: 800px;
    margin: 0 auto;
    line-height: 1.7;
}

/* About Section */
.about {
    background: var(--bg-light);
}

/* Features Section */
.features {
    background: var(--bg-white);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 32px;
    margin-top: 60px;
}

.feature-card {
    background: var(--bg-white);
    padding: 40px 32px;
    border-radius: 20px;
    box-shadow: var(--shadow-md);
    text-align: center;
    transition: all 0.3s ease;
    border: 1px solid var(--border-color);
}

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

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

.feature-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 16px;
    color: var(--text-dark);
}

.feature-card p {
    color: var(--text-light);
    line-height: 1.6;
}

/* Target Users Section */
.target-users {
    background: var(--bg-light);
}

.users-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
    margin-top: 60px;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.user-item {
    display: flex;
    align-items: center;
    gap: 16px;
    background: var(--bg-white);
    padding: 24px;
    border-radius: 16px;
    box-shadow: var(--shadow-sm);
    transition: all 0.2s ease;
}

.user-item:hover {
    box-shadow: var(--shadow-md);
    transform: translateX(4px);
}

.user-item i {
    color: var(--success-color);
    font-size: 20px;
    flex-shrink: 0;
}

.user-item span {
    font-weight: 500;
    color: var(--text-dark);
}

/* Safety Section */
.safety {
    background: var(--bg-white);
}

/* CTA Section */
.cta {
    background: var(--gradient-primary);
    color: white;
}

.cta .section-title {
    color: white;
}

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

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

.footer-section h4 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 20px;
    color: white;
}

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

.footer-section li {
    margin-bottom: 12px;
}

.footer-section a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    transition: color 0.2s ease;
}

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

.social-links {
    display: flex;
    gap: 16px;
}

.social-links a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    transition: all 0.2s ease;
}

.social-links a:hover {
    background: var(--primary-color);
    transform: scale(1.1);
}

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.6);
}

/* Responsive Design */
@media (max-width: 768px) {
    .language-switcher {
        position: static;
        justify-content: center;
        margin: 20px;
        box-shadow: none;
        background: transparent;
    }

    .page-top-bar {
        flex-direction: column;
        gap: 16px;
        padding: 16px 20px;
    }

    .version-switcher {
        gap: 8px;
    }

    .version-btn {
        text-align: center;
        justify-content: center;
        font-size: 0.9rem;
        padding: 8px 12px;
    }

    .hero {
        padding: 60px 0 40px;
        min-height: auto;
    }

    .hero .container {
        grid-template-columns: 1fr;
        gap: 40px;
        text-align: center;
    }

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

    .hero-subtitle {
        font-size: 1.125rem;
    }

    .phone-mockup {
        width: 240px;
        height: 480px;
        order: -1;
    }

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

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

    .users-list {
        grid-template-columns: 1fr;
    }

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

    .download-btn {
        width: 100%;
        max-width: 300px;
        justify-content: center;
    }

    section {
        padding: 60px 0;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }

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

    .section-title {
        font-size: 1.75rem;
    }

    .feature-card,
    .user-item {
        padding: 24px 20px;
    }

    .phone-mockup {
        width: 200px;
        height: 400px;
    }
}

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

.hero-title,
.hero-subtitle,
.download-buttons {
    animation: fadeInUp 0.6s ease-out;
}

.hero-subtitle {
    animation-delay: 0.2s;
}

.download-buttons {
    animation-delay: 0.4s;
}

.phone-mockup {
    animation: fadeInUp 0.6s ease-out 0.3s both;
}

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

/* Focus styles for accessibility */
button:focus,
a:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* Navigation Bar */
.navbar {
    background: var(--bg-white);
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 999;
    padding: 16px 0;
}

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

.nav-brand {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

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

.nav-links a {
    color: var(--text-dark);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s ease;
    position: relative;
}

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

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

.nav-links a.active::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--primary-color);
}

/* Page Header */
.page-header {
    background: var(--gradient-primary);
    color: white;
    padding: 120px 0 60px; /* Increased top padding for fixed header */
    text-align: center;
}

.page-header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 12px;
}

.page-header p {
    font-size: 1rem;
    opacity: 0.9;
}

/* Content Section */
.content-section {
    padding: 60px 0 80px;
    background: var(--bg-light);
}

/* Privacy Content */
.privacy-content {
    background: var(--bg-white);
    border-radius: 20px;
    padding: 48px;
    box-shadow: var(--shadow-md);
    max-width: 900px;
    margin: 0 auto;
}

.privacy-summary {
    background: var(--gradient-primary);
    color: white;
    padding: 32px;
    border-radius: 16px;
    margin-bottom: 40px;
}

.privacy-summary h2 {
    font-size: 1.5rem;
    margin-bottom: 12px;
    display: flex;
    align-items: center;
    gap: 12px;
}

.privacy-summary p {
    font-size: 1rem;
    line-height: 1.7;
    opacity: 0.95;
}

.privacy-section {
    margin-bottom: 48px;
}

.privacy-section h2 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 20px;
    padding-bottom: 12px;
    border-bottom: 2px solid var(--border-color);
}

.privacy-section h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-dark);
    margin-top: 24px;
    margin-bottom: 16px;
}

.privacy-section p {
    color: var(--text-dark);
    line-height: 1.8;
    margin-bottom: 16px;
}

.privacy-section ol,
.privacy-section ul {
    margin-left: 24px;
    margin-bottom: 16px;
}

.privacy-section li {
    color: var(--text-dark);
    line-height: 1.8;
    margin-bottom: 12px;
}

.privacy-section strong {
    font-weight: 600;
    color: var(--text-dark);
}

.privacy-section em {
    font-style: italic;
    color: var(--text-light);
}

.privacy-section hr {
    margin: 32px 0;
    border: none;
    border-top: 1px solid var(--border-color);
}

/* Responsive Design for Privacy Page */
@media (max-width: 768px) {
    .navbar .container {
        flex-direction: column;
        gap: 16px;
    }

    .nav-links {
        gap: 16px;
        flex-wrap: wrap;
        justify-content: center;
    }

    .nav-links a {
        font-size: 0.9rem;
    }

    .page-header {
        padding: 100px 0 40px; /* Adjusted for mobile fixed header */
    }

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

    .privacy-content {
        padding: 32px 24px;
    }

    .privacy-summary {
        padding: 24px;
    }

    .privacy-section h2 {
        font-size: 1.25rem;
    }

    .privacy-section h3 {
        font-size: 1.1rem;
    }
}

@media (max-width: 480px) {
    .nav-links {
        gap: 12px;
    }

    .page-header h1 {
        font-size: 1.75rem;
    }

    .privacy-content {
        padding: 24px 16px;
        border-radius: 12px;
    }

    .privacy-summary {
        padding: 20px;
        border-radius: 12px;
    }

    .privacy-summary h2 {
        font-size: 1.25rem;
    }

    .privacy-section {
        margin-bottom: 32px;
    }

    .privacy-section ol,
    .privacy-section ul {
        margin-left: 16px;
    }
}