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

:root {
    --primary-color: #6366f1;
    --primary-dark: #4f46e5;
    --secondary-color: #f59e0b;
    --accent-color: #10b981;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --text-light: #9ca3af;
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-dark: #111827;
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
    --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-secondary: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --gradient-accent: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    overflow-x: hidden;
    /* 다크모드에서도 밝은 배경 강제 유지 */
    color-scheme: light;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    transition: all 0.3s ease;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.logo-img {
    width: 56px;
    height: 56px;
    border-radius: 8px;
}

.logo-text {
    font-size: 1.75rem;
    font-weight: 700;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-menu {
    display: flex;
    gap: 2rem;
}

.nav-link {
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

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

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient-primary);
    transition: width 0.3s ease;
}

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

.nav-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 4px;
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background: var(--text-primary);
    transition: all 0.3s ease;
}

/* 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::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('../images/snapshot.png') center center/cover no-repeat;
    opacity: 0.35;
    filter: blur(8px) brightness(1.1) saturate(1.1);
    z-index: 0;
    pointer-events: none;
}

.hero > * {
    position: relative;
    z-index: 1;
}

.hero-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
    position: relative;
    z-index: 1;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1.5rem;
}

.gradient-text {
    background: linear-gradient(135deg, #cfdb2b 0%, #3df10b 30%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-description {
    font-size: 1.25rem;
    line-height: 1.7;
    margin-bottom: 2.5rem;
    opacity: 0.9;
}

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

.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.875rem 1.75rem;
    border-radius: 12px;
    text-decoration: none;
    font-weight: 600;
    font-size: 1rem;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.5s ease;
}

.btn:hover::before {
    left: 100%;
}

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

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

.btn-secondary {
    background: rgba(255, 255, 255, 0.1);
    color: white;
    border: 2px solid rgba(255, 255, 255, 0.3);
    backdrop-filter: blur(10px);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.2);
    border-color: rgba(255, 255, 255, 0.5);
    transform: translateY(-2px);
}

.btn-large {
    padding: 1rem 2rem;
    font-size: 1.125rem;
}

.btn-icon {
    width: 20px;
    height: 20px;
    fill: currentColor;
}

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

.app-icon {
    width: 200px;
    height: 200px;
    border-radius: 24px;
    box-shadow: var(--shadow-xl);
    animation: float 6s ease-in-out infinite;
}

.floating-card {
    position: absolute;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 12px;
    padding: 0.75rem 1rem;
    font-size: 0.875rem;
    font-weight: 500;
    animation: float 4s ease-in-out infinite;
}

.card-1 {
    top: -20px;
    left: -40px;
    animation-delay: 0s;
}

.card-2 {
    top: 50%;
    right: -60px;
    animation-delay: 1s;
}

.card-3 {
    bottom: -20px;
    left: 20px;
    animation-delay: 2s;
}

@keyframes float {
    0%, 100% {
        transform: translateY(0px);
    }
    50% {
        transform: translateY(-20px);
    }
}

/* Section Styles */
.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.section-description {
    font-size: 1.125rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

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

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
}

.feature-card {
    background: white;
    padding: 2rem;
    border-radius: 16px;
    box-shadow: var(--shadow-md);
    transition: all 0.3s ease;
    border: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}

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

.feature-icon {
    width: 60px;
    height: 60px;
    background: var(--gradient-accent);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
    flex-shrink: 0;
}

.feature-icon svg {
    width: 30px;
    height: 30px;
    fill: white;
}

.feature-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

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

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

.steps-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.step {
    display: flex;
    align-items: flex-start;
    gap: 1.5rem;
    padding: 2rem;
    background: var(--bg-secondary);
    border-radius: 16px;
    transition: all 0.3s ease;
}

.step:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.step-number {
    width: 50px;
    height: 50px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    font-weight: 700;
    color: white;
    flex-shrink: 0;
}

.step-content h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

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

/* Download Section */
.download {
    padding: 80px 0;
    background: var(--gradient-primary);
    color: white;
    text-align: center;
}

.download-content h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.download-content p {
    font-size: 1.25rem;
    margin-bottom: 2.5rem;
    opacity: 0.9;
}

/* App Screenshots Section */
.app-screenshots {
    padding: 80px 0;
    background: var(--bg-secondary);
}

@media (max-width: 768px) {
    .app-screenshots {
        background: var(--bg-primary);
    }
}

.screenshots-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(125px, 1fr));
    gap: 1rem;
    margin-top: 3rem;
    position: relative;
    z-index: 1;
}

.screenshot-item {
    background: var(--bg-primary);
    border-radius: 16px;
    padding: 1rem;
    box-shadow: var(--shadow-md);
    transition: all 0.3s ease;
    cursor: pointer;
    overflow: visible;
    position: relative;
}

.screenshot-item:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
    z-index: 1000;
}

.screenshot-img {
    width: 100%;
    height: auto;
    border-radius: 8px;
    transition: transform 0.3s ease;
    display: block;
}

.screenshot-item:hover .screenshot-img {
    transform: scale(2.5);
    z-index: 1001;
    position: relative;
}

/* 확대된 이미지를 위한 오버레이 */
.screenshot-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.8);
    z-index: 9999;
    display: none;
    justify-content: center;
    align-items: center;
    cursor: pointer;
}

.screenshot-overlay.active {
    display: flex;
}

.screenshot-overlay img {
    max-width: 90%;
    max-height: 90%;
    border-radius: 12px;
    box-shadow: var(--shadow-xl);
    transform: scale(1);
    transition: transform 0.3s ease;
}

.screenshot-overlay img:hover {
    transform: scale(1.05);
}

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

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

.footer-section h3,
.footer-section h4 {
    margin-bottom: 1rem;
    color: white;
}

.footer-section h3 {
    font-size: 1.5rem;
    font-weight: 700;
}

.footer-section h4 {
    font-size: 1.125rem;
    font-weight: 600;
}

.footer-section p {
    color: #9ca3af;
    line-height: 1.6;
}

.footer-bottom {
    border-top: 1px solid #374151;
    padding-top: 2rem;
    text-align: center;
    color: #9ca3af;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }
    
    .nav-toggle {
        display: flex;
    }
    
    /* 모바일에서 로고 텍스트 크기 줄이기 */
    .logo-text {
        font-size: 1.25rem;
    }
    
    .hero-container {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 2rem;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-buttons {
        justify-content: center;
    }
    
    .app-icon {
        width: 150px;
        height: 150px;
    }
    
    .floating-card {
        display: none;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .steps-container {
        grid-template-columns: 1fr;
    }
    
    .step {
        flex-direction: row;
        text-align: left;
        gap: 1rem;
        align-items: flex-start;
    }
    
    .step-number {
        margin-bottom: 0;
        flex-shrink: 0;
        width: 40px;
        height: 40px;
        font-size: 1rem;
        color: white;
    }
    
    .step-content {
        width: 100%;
        text-align: left;
    }
    
    /* feature-card도 모바일에서 컬럼 레이아웃 적용 */
    .feature-card {
        flex-direction: column;
        text-align: center;
        gap: 1rem;
        align-items: center;
    }
    
    .feature-icon {
        margin-bottom: 0.5rem;
    }
    
    .feature-card h3 {
        margin-bottom: 0.75rem;
    }
    
    .feature-card p {
        margin: 0;
    }
    
    .download-content h2 {
        font-size: 2rem;
        color: white;
    }
    
    .download-content p {
        color: white;
    }
    
    .screenshots-grid {
        grid-template-columns: repeat(auto-fit, minmax(100px, 1fr));
        gap: 0.75rem;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    /* 모바일에서 footer 텍스트 컬러 확실히 하기 */
    .footer {
        color: white;
    }
    
    .footer-section h3,
    .footer-section h4 {
        color: white;
    }
    
    .footer-section p {
        color: white;
    }
    
    .footer-bottom {
        color: white;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }
    
    /* 더 작은 화면에서 로고 텍스트 크기 줄이기 */
    .logo-text {
        font-size: 1rem;
    }
    
    .hero-description {
        font-size: 1rem;
    }
    
    .btn {
        padding: 0.75rem 1.5rem;
        font-size: 0.875rem;
    }
    
    .feature-card {
        padding: 1.5rem;
    }
    
    .step {
        padding: 1.5rem;
        gap: 0.75rem;
        flex-direction: row;
        text-align: left;
        align-items: flex-start;
    }
    
    .step-number {
        margin-bottom: 0;
        flex-shrink: 0;
        width: 35px;
        height: 35px;
        font-size: 0.875rem;
        color: white;
    }
    
    .step-content {
        text-align: left;
    }
    
    .feature-card {
        padding: 1.5rem;
        gap: 0.75rem;
        align-items: center;
    }
    
    .feature-icon {
        margin-bottom: 0.25rem;
        width: 45px;
        height: 45px;
    }
    
    .feature-icon svg {
        width: 22px;
        height: 22px;
    }
    
    .feature-card h3 {
        margin-bottom: 0.5rem;
        font-size: 1.125rem;
    }
    
    .feature-card p {
        margin: 0;
        font-size: 0.95rem;
    }
    
    /* Download 섹션 텍스트 컬러 확실히 하기 */
    .download {
        color: white;
    }
    
    .download-content h2,
    .download-content p {
        color: white;
    }
    
    /* 더 작은 화면에서 footer 텍스트 컬러 확실히 하기 */
    .footer {
        color: white;
    }
    
    .footer-section h3,
    .footer-section h4,
    .footer-section p {
        color: white;
    }
    
    .footer-bottom {
        color: white;
    }
    
    .screenshots-grid {
        grid-template-columns: repeat(auto-fit, minmax(80px, 1fr));
        gap: 0.5rem;
    }
    
    .screenshot-item {
        padding: 0.5rem;
    }
    
    /* Extra small screen language selector */
    .language-selector {
        top: 70px;
        right: 5px;
        min-width: 100px;
        max-width: 150px;
        left: auto;
        transform: none;
    }
    
    .lang-toggle {
        padding: 0.375rem 0.5rem;
        font-size: 0.7rem;
    }
    
    .current-lang-name {
        max-width: 60px;
        font-size: 0.7rem;
    }
    
    .lang-btn {
        padding: 0.25rem 0.5rem;
        font-size: 0.7rem;
    }
    
    .lang-name {
        max-width: 100px;
        font-size: 0.7rem;
    }
}

/* Smooth Scrolling */
html {
    scroll-behavior: smooth;
    /* 모바일에서 스크롤 성능 향상 */
    -webkit-overflow-scrolling: touch;
}

/* 모바일에서 스크롤 최적화 */
@media (max-width: 768px) {
    html {
        scroll-behavior: auto; /* 모바일에서는 즉시 스크롤 */
    }
    
    body {
        /* 모바일에서 스크롤 성능 향상 */
        -webkit-overflow-scrolling: touch;
        overflow-x: hidden;
    }
    
    /* 모바일에서 섹션 간격 최적화 */
    section {
        padding: 40px 0; /* 모바일에서는 더 작은 패딩 */
    }
    
    .features {
        padding: 40px 0;
    }
    
    .app-screenshots {
        padding: 40px 0;
    }
    
    .how-to-use {
        padding: 40px 0;
    }
    
    .download {
        padding: 40px 0;
    }
}

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

.feature-card,
.step {
    animation: fadeInUp 0.6s ease-out;
    /* 하드웨어 가속 활성화 */
    will-change: transform, opacity;
    transform: translateZ(0);
}

/* 모바일에서 애니메이션 최적화 */
@media (max-width: 768px) {
    .feature-card,
    .step {
        animation: none;
        opacity: 1;
        transform: translateY(0);
        transition: none;
    }
    
    /* 모바일에서 호버 효과 단순화 */
    .feature-card:hover .feature-icon {
        transform: none;
    }
    
    /* 모바일에서 feature-icon 크기 조정 */
    .feature-icon {
        width: 50px;
        height: 50px;
    }
    
    .feature-icon svg {
        width: 25px;
        height: 25px;
    }
    
    .step:hover .step-number {
        transform: none;
    }
    
    /* 모바일에서 스크롤 성능 향상 */
    * {
        -webkit-overflow-scrolling: touch;
    }
    
    /* 모바일에서 transform 최적화 */
    .screenshot-item:hover .screenshot-img {
        transform: scale(1.5); /* 모바일에서는 더 작은 확대 */
        transition: transform 0.2s ease; /* 더 빠른 전환 */
    }
}

/* Hover Effects */
.feature-card:hover .feature-icon {
    transform: scale(1.1);
}

.step:hover .step-number {
    transform: scale(1.1);
}

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

/* Navigation Language Selector */
.nav-language-selector {
    position: relative;
    display: inline-block;
}

.nav-lang-toggle {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 0.75rem;
    border: none;
    background: transparent;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-primary);
    text-decoration: none;
}

.nav-lang-toggle:hover {
    background: rgba(99, 102, 241, 0.1);
    color: var(--primary-color);
}

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

.nav-current-lang-name {
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    max-width: 120px;
}

.nav-lang-arrow {
    width: 12px;
    height: 12px;
    fill: currentColor;
    transition: transform 0.3s ease;
}

.nav-lang-toggle.active .nav-lang-arrow {
    transform: rotate(180deg);
}

.nav-lang-dropdown {
    display: none;
    position: absolute;
    top: 100%;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-radius: 12px;
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border-color);
    min-width: 140px;
    max-width: 200px;
    z-index: 1000;
    overflow: hidden;
}

.nav-lang-dropdown.show {
    display: block;
}

.nav-lang-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 0.75rem;
    border: none;
    background: transparent;
    border-radius: 0;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-primary);
    width: 100%;
    text-align: left;
}

.nav-lang-btn:hover {
    background: var(--primary-color);
    color: white;
}

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

.nav-lang-name {
    white-space: nowrap;
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    text-align: center;
}

/* Legacy Language Selector (for mobile) */
.language-selector {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 9999;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-radius: 12px;
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
    min-width: 140px;
    max-width: 200px;
    overflow: hidden;
    display: none;
}

/* Force mobile language selector to be visible on mobile */
@media (max-width: 768px) {
    .language-selector {
        display: block !important;
        visibility: visible !important;
        opacity: 1 !important;
        pointer-events: auto !important;
        position: fixed !important;
        z-index: 9999 !important;
        top: 80px !important;
        right: 10px !important;
        min-width: 120px !important;
        max-width: 200px !important;
        left: auto !important;
        transform: none !important;
        background: rgba(255, 255, 255, 0.95) !important;
        backdrop-filter: blur(10px) !important;
        border-radius: 12px !important;
        box-shadow: var(--shadow-lg) !important;
        border: 1px solid var(--border-color) !important;
    }
    
    .language-selector .lang-toggle {
        display: flex !important;
        align-items: center !important;
        gap: 0.5rem !important;
        padding: 0.5rem 0.75rem !important;
        border: none !important;
        background: transparent !important;
        border-radius: 12px !important;
        cursor: pointer !important;
        transition: all 0.3s ease !important;
        font-size: 0.75rem !important;
        font-weight: 500 !important;
        color: var(--text-primary) !important;
        width: 100% !important;
        justify-content: space-between !important;
    }
    
    .language-selector .lang-dropdown {
        display: none !important;
        flex-direction: column !important;
        gap: 0.25rem !important;
        padding: 0.5rem !important;
        border-top: 1px solid var(--border-color) !important;
        max-height: 250px !important;
        overflow-y: auto !important;
    }
    
    .language-selector .lang-dropdown.show {
        display: flex !important;
    }
    
    /* Completely disable desktop language selector on mobile */
    .nav-language-selector,
    .nav-lang-toggle,
    .nav-lang-dropdown {
        display: none !important;
        visibility: hidden !important;
        opacity: 0 !important;
        pointer-events: none !important;
        position: absolute !important;
        left: -9999px !important;
        top: -9999px !important;
    }
}

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

/* Language Toggle Button */
.lang-toggle {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1rem;
    border: none;
    background: transparent;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-primary);
    width: 100%;
    justify-content: space-between;
}

.lang-toggle:hover {
    background: rgba(99, 102, 241, 0.1);
}

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

.current-lang-name {
    white-space: nowrap;
    flex: 1;
    text-align: left;
    overflow: hidden;
    text-overflow: ellipsis;
}

.lang-arrow {
    width: 16px;
    height: 16px;
    fill: currentColor;
    transition: transform 0.3s ease;
}

.lang-toggle.active .lang-arrow {
    transform: rotate(180deg);
}

/* Language Dropdown */
.lang-dropdown {
    display: none;
    flex-direction: column;
    gap: 0.25rem;
    padding: 0.5rem;
    border-top: 1px solid var(--border-color);
    max-height: 300px;
    overflow-y: auto;
}

.lang-dropdown.show {
    display: flex;
}

.lang-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 0.75rem;
    border: none;
    background: transparent;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-primary);
    width: 100%;
    text-align: left;
}

.lang-btn:hover {
    background: var(--primary-color);
    color: white;
    transform: translateX(5px);
}

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

.lang-name {
    white-space: nowrap;
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    text-align: center;
}

/* Mobile Language Selector */
@media (max-width: 768px) {
    .nav-language-selector {
        display: none !important;
        visibility: hidden !important;
        opacity: 0 !important;
        pointer-events: none !important;
    }
    
    .nav-lang-toggle,
    .nav-lang-dropdown {
        display: none !important;
        visibility: hidden !important;
        opacity: 0 !important;
        pointer-events: none !important;
    }
    
    .language-selector {
        display: block !important;
        visibility: visible !important;
        opacity: 1 !important;
        pointer-events: auto !important;
        top: 80px;
        right: 10px;
        min-width: 120px;
        max-width: 200px;
        left: auto;
        transform: none;
    }
    
    .lang-toggle {
        padding: 0.5rem 0.75rem;
        font-size: 0.75rem;
    }
    
    .current-lang-name {
        font-size: 0.75rem;
        overflow: hidden;
        text-overflow: ellipsis;
        white-space: nowrap;
        max-width: 100px;
    }
    
    .lang-btn {
        padding: 0.375rem 0.5rem;
        font-size: 0.75rem;
    }
    
    .lang-name {
        font-size: 0.75rem;
        overflow: hidden;
        text-overflow: ellipsis;
        white-space: nowrap;
        max-width: 100px;
    }
    
    .lang-dropdown {
        max-height: 250px;
    }
}

/* Dark Mode Support - 강제로 밝은 테마 유지 */
@media (prefers-color-scheme: dark) {
    :root {
        /* 다크모드에서도 밝은 테마 유지 */
        --text-primary: #1f2937;
        --text-secondary: #6b7280;
        --text-light: #9ca3af;
        --bg-primary: #ffffff;
        --bg-secondary: #f9fafb;
        --border-color: #e5e7eb;
    }
    
    body {
        background-color: var(--bg-primary);
        color: var(--text-primary);
    }
    
    .navbar {
        background: rgba(255, 255, 255, 0.95);
        border-bottom-color: var(--border-color);
    }
    
    .feature-card {
        background: var(--bg-primary);
        border-color: var(--border-color);
        color: var(--text-primary);
    }
    
    .step {
        background: var(--bg-primary);
        color: var(--text-primary);
    }
    
    .step-number {
        color: white !important;
    }
    
    .download {
        color: white !important;
    }
    
    .download-content h2,
    .download-content p {
        color: white !important;
    }
    
    .language-selector {
        background: rgba(255, 255, 255, 0.95);
        border-color: var(--border-color);
        color: var(--text-primary);
    }
    
    .app-screenshots {
        background: var(--bg-secondary);
    }
    
    .screenshot-item {
        background: var(--bg-primary);
        color: var(--text-primary);
    }
    
    .screenshot-overlay {
        background: rgba(0, 0, 0, 0.8);
    }
    
    /* 모든 텍스트 요소가 검정색으로 표시되도록 강제 설정 */
    h1, h2, h3, h4, h5, h6, p, span, div, a, button {
        color: var(--text-primary) !important;
    }
    
    /* 특정 요소들에 대한 추가 설정 */
    .hero-title, .hero-description {
        color: white !important; /* 히어로 섹션은 흰색 유지 */
    }
    
    /* footer 내부의 모든 텍스트 요소는 백색으로 강제 설정 */
    .footer h1, .footer h2, .footer h3, .footer h4, .footer h5, .footer h6,
    .footer p, .footer span, .footer div, .footer a, .footer button {
        color: white !important;
    }
    
    .footer {
        background: var(--bg-dark);
        color: white !important;
    }
    
    .footer * {
        color: white !important;
    }
    
    .footer-section h3,
    .footer-section h4 {
        color: white !important;
    }
    
    .footer-section p {
        color: white !important;
    }
    
    .footer-bottom {
        color: white !important;
    }
    
    .footer-content {
        color: white !important;
    }
}

/* YouTube Preview Section */
.youtube-preview {
    padding: 80px 0;
    background: var(--bg-secondary);
}

.youtube-video-container {
    width: 650px;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow-lg);
    background: #f0f0f0;
}

.youtube-video-container iframe {
    border: none;
    border-radius: 12px;
    width: 100%;
    height: 365px;
    display: block;
}

@media (max-width: 768px) {
    .youtube-video-container {
        width: 100%;
        margin: 0 1rem;
    }
    
    .youtube-video-container iframe {
        width: 100%;
        height: auto;
        min-height: 200px;
    }
}