/* CSS Variables - FE 프로젝트 디자인 시스템 반영 */
:root {
    /* Primary colors */
    --color-primary-dark: #2A2418;
    --color-primary: #5A4A3A;
    --color-primary-light: #6B5D4F;
    --color-primary-lighter: #9A8C7A;
    
    /* Background colors */
    --color-background: #FAF8F4;
    --color-background-light: #F5F0E8;
    --color-background-lighter: #ECE4D7;
    --color-background-card: #E8DCC8;
    --color-background-hover: #EFE6D8;
    
    /* Border colors */
    --color-border: rgba(90, 74, 58, 0.15);
    --color-border-light: #E6DFD2;
    
    /* Text colors */
    --color-text-primary: #2A2418;
    --color-text-secondary: #6B5D4F;
    --color-text-tertiary: #9A8C7A;
    
    /* Fonts */
    --font-playfair: 'Playfair Display', serif;
    --font-inter: 'Inter', sans-serif;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    
    /* Border radius */
    --radius-sm: 0.5rem;
    --radius-md: 1rem;
    --radius-lg: 1.5rem;
    --radius-xl: 2rem;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-inter);
    color: var(--color-text-primary);
    background-color: var(--color-background);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(250, 248, 244, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 2px solid var(--color-border);
    z-index: 1000;
    padding: var(--spacing-sm) 0;
}

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

.nav-brand {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.nav-logo {
    width: 40px;
    height: 40px;
    object-fit: contain;
}

.nav-title {
    font-family: var(--font-playfair);
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--color-primary);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--spacing-lg);
}

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

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

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--color-primary);
    transition: width 0.3s ease;
}

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

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

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

/* Hero Section */
.hero {
    margin-top: 80px;
    padding: var(--spacing-2xl) 0;
    background: linear-gradient(180deg, #F5F1E8 0%, #FAF8F3 50%, #F0EBE0 100%);
    text-align: center;
}

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

.hero-logo {
    width: 120px;
    height: 120px;
    margin: 0 auto var(--spacing-lg);
    object-fit: contain;
}

.hero-title {
    font-family: var(--font-playfair);
    font-size: 3rem;
    font-weight: 600;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-md);
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-lg);
    font-weight: 500;
}

.hero-description {
    font-size: 1.1rem;
    color: var(--color-text-secondary);
    line-height: 1.8;
    margin-bottom: var(--spacing-xl);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    flex-wrap: wrap;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.875rem 2rem;
    border-radius: var(--radius-sm);
    text-decoration: none;
    font-weight: 500;
    font-size: 1rem;
    transition: all 0.3s ease;
    cursor: pointer;
    border: none;
    font-family: var(--font-inter);
}

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

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

.btn-secondary {
    background: var(--color-background-light);
    color: var(--color-text-primary);
    border: 2px solid var(--color-border);
}

.btn-secondary:hover {
    background: var(--color-background-card);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

/* Quote Banner */
.quote-banner {
    padding: var(--spacing-xl) 0;
    background: var(--color-background-light);
    border-top: 2px solid var(--color-border);
    border-bottom: 2px solid var(--color-border);
}

.quote-text {
    font-family: var(--font-playfair);
    font-size: 1.5rem;
    font-style: italic;
    color: var(--color-text-primary);
    text-align: center;
    margin-bottom: var(--spacing-md);
    max-width: 900px;
    margin-left: auto;
    margin-right: auto;
}

.quote-author {
    display: block;
    font-family: var(--font-inter);
    font-size: 1rem;
    font-style: italic;
    color: var(--color-text-secondary);
    text-align: center;
}

/* Section Styles */
section {
    padding: var(--spacing-2xl) 0;
}

.section-title {
    font-family: var(--font-playfair);
    font-size: 2.5rem;
    font-weight: 600;
    color: var(--color-text-primary);
    text-align: center;
    margin-bottom: var(--spacing-md);
}

.section-description {
    text-align: center;
    color: var(--color-text-secondary);
    font-size: 1.1rem;
    max-width: 700px;
    margin: 0 auto var(--spacing-xl);
}

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

.features-slider-wrapper {
    position: relative;
    margin-top: var(--spacing-xl);
    padding: 0 80px;
}

.features-slider {
    overflow: hidden;
    position: relative;
    margin: 0 -40px;
    padding: 0 40px;
}

.features-track {
    display: flex;
    transition: transform 0.5s cubic-bezier(0.4, 0, 0.2, 1);
    will-change: transform;
    gap: var(--spacing-lg);
}

.feature-card {
    background: white;
    border: 2px solid var(--color-border);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-sm);
    transition: all 0.3s ease;
    flex: 0 0 calc(85% - var(--spacing-lg) / 2);
    min-width: 0;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    margin-right: 0;
}

.feature-card:last-child {
    margin-right: 0;
}

.feature-card:hover {
    box-shadow: var(--shadow-lg);
    border-color: var(--color-primary-light);
}

.feature-image-wrapper {
    width: 100%;
    height: 400px;
    overflow: hidden;
    background: var(--color-background-light);
    display: flex;
    align-items: center;
    justify-content: center;
}

.feature-image {
    width: 100%;
    height: 100%;
    object-fit: contain;
    object-position: center;
}

.feature-content {
    padding: var(--spacing-xl);
    flex: 1;
    display: flex;
    flex-direction: column;
}

.slider-btn {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background: white;
    border: 2px solid var(--color-border);
    border-radius: 50%;
    width: 50px;
    height: 50px;
    font-size: 2rem;
    color: var(--color-primary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
    z-index: 10;
    box-shadow: var(--shadow-md);
}

.slider-btn:hover {
    background: var(--color-primary);
    color: white;
    border-color: var(--color-primary);
    transform: translateY(-50%) scale(1.1);
}

.slider-btn-prev {
    left: 0;
}

.slider-btn-next {
    right: 0;
}

.slider-dots {
    display: flex;
    justify-content: center;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-lg);
}

.dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    border: 2px solid var(--color-primary);
    background: transparent;
    cursor: pointer;
    transition: all 0.3s ease;
    padding: 0;
}

.dot:hover {
    background: var(--color-primary-light);
}

.dot.active {
    background: var(--color-primary);
}

.feature-title {
    font-family: var(--font-playfair);
    font-size: 1.75rem;
    font-weight: 600;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-xs);
}

.feature-subtitle {
    font-size: 1rem;
    color: var(--color-text-secondary);
    font-weight: 500;
    margin-bottom: var(--spacing-md);
}

.feature-description {
    color: var(--color-text-secondary);
    line-height: 1.7;
    margin-bottom: var(--spacing-md);
}

.feature-list {
    list-style: none;
    padding-left: 0;
}

.feature-list li {
    color: var(--color-text-secondary);
    padding: var(--spacing-xs) 0;
    padding-left: var(--spacing-md);
    position: relative;
}

.feature-list li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--color-primary);
    font-weight: bold;
}

/* Installation Section */
.installation {
    background: var(--color-background-light);
}

.download-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-xl);
    margin-top: var(--spacing-xl);
}

.download-card {
    background: white;
    border: 2px solid var(--color-border);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: all 0.3s ease;
}

.download-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--color-primary-light);
}

.download-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-md);
}

.download-title {
    font-family: var(--font-playfair);
    font-size: 1.75rem;
    font-weight: 600;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-sm);
}

.download-description {
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-md);
    line-height: 1.6;
}

.download-info {
    display: flex;
    justify-content: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
    flex-wrap: wrap;
}

.download-version,
.download-size {
    font-size: 0.9rem;
    color: var(--color-text-tertiary);
    background: var(--color-background-light);
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-sm);
}

.download-btn {
    width: 100%;
    margin-bottom: var(--spacing-sm);
}

.download-note {
    font-size: 0.875rem;
    color: var(--color-text-tertiary);
    line-height: 1.5;
}

/* Installation Instructions */
.installation-instructions {
    margin-top: var(--spacing-2xl);
    background: white;
    border: 2px solid var(--color-border);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
}

.instructions-title {
    font-family: var(--font-playfair);
    font-size: 1.75rem;
    font-weight: 600;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-lg);
    text-align: center;
}

.instructions-tabs {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-lg);
    border-bottom: 2px solid var(--color-border-light);
}

.tab-btn {
    padding: var(--spacing-sm) var(--spacing-lg);
    background: none;
    border: none;
    border-bottom: 3px solid transparent;
    font-family: var(--font-inter);
    font-size: 1rem;
    font-weight: 500;
    color: var(--color-text-secondary);
    cursor: pointer;
    transition: all 0.3s ease;
    margin-bottom: -2px;
}

.tab-btn:hover {
    color: var(--color-primary);
}

.tab-btn.active {
    color: var(--color-primary);
    border-bottom-color: var(--color-primary);
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

.instructions-list {
    list-style: none;
    counter-reset: step-counter;
    padding-left: 0;
}

.instructions-list li {
    counter-increment: step-counter;
    padding: var(--spacing-md) 0;
    padding-left: var(--spacing-2xl);
    position: relative;
    color: var(--color-text-secondary);
    line-height: 1.7;
}

.instructions-list li::before {
    content: counter(step-counter);
    position: absolute;
    left: 0;
    top: var(--spacing-md);
    width: 28px;
    height: 28px;
    background: var(--color-primary);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    font-size: 0.875rem;
}

.instructions-list code {
    background: var(--color-background-light);
    padding: 0.125rem 0.5rem;
    border-radius: 4px;
    font-family: 'Courier New', monospace;
    font-size: 0.9em;
    color: var(--color-primary);
}

/* Changelog Section */
.changelog {
    background: var(--color-background);
}

.changelog-container {
    max-width: 900px;
    margin: 0 auto;
}

.version-card {
    background: white;
    border: 2px solid var(--color-border);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
    margin-bottom: var(--spacing-lg);
    box-shadow: var(--shadow-sm);
}

.version-card.future {
    opacity: 0.7;
    border-style: dashed;
}

.version-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-md);
    border-bottom: 2px solid var(--color-border-light);
}

.version-title {
    font-family: var(--font-playfair);
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--color-primary);
}

.version-date {
    font-size: 0.9rem;
    color: var(--color-text-tertiary);
}

.version-content {
    color: var(--color-text-secondary);
}

.version-section-title {
    font-family: var(--font-playfair);
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-md);
}

.version-changes {
    margin-top: var(--spacing-md);
}

.change-category {
    margin-bottom: var(--spacing-md);
}

.change-type {
    font-weight: 600;
    font-size: 1rem;
    margin-bottom: var(--spacing-sm);
    color: var(--color-text-primary);
}

.change-type.added {
    color: #059669;
}

.change-type.changed {
    color: #D97706;
}

.change-type.fixed {
    color: #DC2626;
}

.change-category ul {
    list-style: none;
    padding-left: var(--spacing-md);
}

.change-category li {
    padding: var(--spacing-xs) 0;
    padding-left: var(--spacing-md);
    position: relative;
    color: var(--color-text-secondary);
    line-height: 1.6;
}

.change-category li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--color-primary);
    font-weight: bold;
    font-size: 1.2rem;
}

.future-note {
    color: var(--color-text-tertiary);
    font-style: italic;
    text-align: center;
    padding: var(--spacing-md);
}

/* Footer */
.footer {
    background: var(--color-primary-dark);
    color: var(--color-background);
    padding: var(--spacing-xl) 0;
    margin-top: var(--spacing-2xl);
}

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

.footer-brand {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
}

.footer-logo {
    width: 40px;
    height: 40px;
    object-fit: contain;
}

.footer-title {
    font-family: var(--font-playfair);
    font-size: 1.5rem;
    font-weight: 600;
}

.footer-description {
    color: rgba(250, 248, 244, 0.8);
    margin-bottom: var(--spacing-md);
}

.footer-links {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
    flex-wrap: wrap;
}

.footer-link {
    color: rgba(250, 248, 244, 0.8);
    text-decoration: none;
    transition: color 0.3s ease;
}

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

.footer-separator {
    color: rgba(250, 248, 244, 0.5);
}

.footer-copyright {
    color: rgba(250, 248, 244, 0.6);
    font-size: 0.875rem;
}

/* Mobile Menu Toggle */
.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--color-primary);
    cursor: pointer;
    padding: var(--spacing-xs);
}

/* Responsive Design */
@media (max-width: 768px) {
    .mobile-menu-toggle {
        display: block;
    }
    
    .nav-menu {
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background: rgba(250, 248, 244, 0.98);
        backdrop-filter: blur(10px);
        flex-direction: column;
        padding: var(--spacing-md);
        border-bottom: 2px solid var(--color-border);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all 0.3s ease;
        gap: var(--spacing-sm);
    }
    
    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .nav-link {
        font-size: 1rem;
        padding: var(--spacing-sm);
        display: block;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1.1rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .features-slider-wrapper {
        padding: 0 50px;
    }
    
    .slider-btn {
        width: 40px;
        height: 40px;
        font-size: 1.5rem;
    }
    
    .feature-card {
        flex: 0 0 calc(90% - var(--spacing-lg) / 2);
    }
    
    .feature-image-wrapper {
        height: 250px;
    }
    
    .feature-content {
        padding: var(--spacing-md);
    }
    
    .download-grid {
        grid-template-columns: 1fr;
    }
    
    .hero-buttons {
        flex-direction: column;
        align-items: stretch;
    }
    
    .btn {
        width: 100%;
    }
    
    .version-header {
        flex-direction: column;
        align-items: flex-start;
        gap: var(--spacing-xs);
    }
    
    .instructions-tabs {
        flex-direction: column;
    }
    
    .tab-btn {
        width: 100%;
        text-align: left;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 var(--spacing-sm);
    }
    
    .hero {
        padding: var(--spacing-xl) 0;
    }
    
    section {
        padding: var(--spacing-xl) 0;
    }
    
    .hero-logo {
        width: 80px;
        height: 80px;
    }
    
    .hero-title {
        font-size: 1.75rem;
    }
    
    .quote-text {
        font-size: 1.25rem;
    }
}