/* ==========================================================================
   CSS Variables (Custom Properties)
   ========================================================================== */
:root {
    /* Colors */
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --secondary-color: #64748b;
    --accent-color: #3b82f6;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --error-color: #ef4444;
    
    /* Background Colors */
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-dark: #0f172a;
    --bg-card: #ffffff;
    --bg-gradient: linear-gradient(135deg, #3b82f6 0%, #1d4ed8 100%);
    --hero-gradient: linear-gradient(135deg, #3b82f6 0%, #1d4ed8 50%, #1e40af 100%);
    --hero-gradient-modern: linear-gradient(135deg, #3b82f6 0%, #1d4ed8 50%, #1e40af 100%);
    
    /* Text Colors */
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-muted: #94a3b8;
    --text-white: #ffffff;
    
    /* Border Colors */
    --border-color: #e2e8f0;
    --border-hover: #cbd5e1;
    
    /* 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);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    
    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
    
    /* Spacing */
    --section-padding: 5rem 0;
    --container-padding: 0 1rem;
    --grid-gap: 2rem;
    
    /* Animation */
    --transition: all 0.3s ease;
    --transition-fast: all 0.15s ease;
}

/* Dark mode variables */
@media (prefers-color-scheme: dark) {
    :root {
        --bg-primary: #0f172a;
        --bg-secondary: #1e293b;
        --bg-card: #1e293b;
        --text-primary: #f1f5f9;
        --text-secondary: #cbd5e1;
        --text-muted: #64748b;
        --border-color: #374151;
        --border-hover: #4b5563;
    }
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-primary);
    color: var(--text-primary);
    background-color: var(--bg-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

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

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

/* ==========================================================================
   Utility Classes
   ========================================================================== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--container-padding);
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    font-weight: 500;
    border-radius: 0.5rem;
    border: none;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
    font-size: 0.95rem;
    gap: 0.5rem;
}

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

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

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

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

.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(--text-white);
}

.btn-github {
    background-color: #24292e;
    color: var(--text-white);
}

.btn-github:hover {
    background-color: #1a1e22;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.section-subtitle {
    font-size: 1.125rem;
    text-align: center;
    color: var(--text-secondary);
    margin-bottom: 3rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.highlight {
    background: linear-gradient(135deg, #3b82f6 0%, #1d4ed8 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Animation classes */
.animate-in {
    opacity: 1;
    transform: translateY(0);
}

.solution-card,
.feature-item,
.tech-category {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.solution-card.animate-in,
.feature-item.animate-in,
.tech-category.animate-in {
    opacity: 1;
    transform: translateY(0);
}

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

.navbar.scrolled {
    background-color: rgba(255, 255, 255, 0.98);
    box-shadow: var(--shadow-md);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 4rem;
}

.nav-brand {
    display: flex;
    align-items: center;
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--text-primary);
}

.brand-icon {
    font-size: 1.5rem;
    margin-right: 0.5rem;
    background: linear-gradient(135deg, #3b82f6 0%, #1d4ed8 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    filter: drop-shadow(0 2px 4px rgba(59, 130, 246, 0.2));
}

.nav-list {
    display: flex;
    list-style: none;
    gap: 2rem;
    margin: 0;
    padding: 0;
}

.nav-link {
    font-weight: 500;
    color: var(--text-secondary);
    padding: 0.5rem 0;
    position: relative;
}

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

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -0.5rem;
    left: 0;
    right: 0;
    height: 2px;
    background-color: var(--primary-color);
    border-radius: 1px;
}

/* Dropdown menu */
.dropdown {
    position: relative;
}

.dropdown-toggle {
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.dropdown-arrow {
    font-size: 0.75rem;
    transition: var(--transition);
}

.dropdown:hover .dropdown-arrow {
    transform: rotate(180deg);
}

.dropdown-menu {
    position: absolute;
    top: 100%;
    left: 0;
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    box-shadow: var(--shadow-lg);
    min-width: 250px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: var(--transition);
    list-style: none;
    padding: 0.5rem 0;
    margin: 0;
    z-index: 100;
}

.dropdown:hover .dropdown-menu,
.dropdown-menu.active {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown-link {
    display: block;
    padding: 0.75rem 1rem;
    color: var(--text-secondary);
    transition: var(--transition-fast);
}

.dropdown-link:hover {
    background-color: var(--bg-secondary);
    color: var(--primary-color);
}

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
    padding: 0.5rem;
    gap: 0.25rem;
}

.mobile-menu-toggle span {
    width: 1.5rem;
    height: 2px;
    background-color: var(--text-primary);
    transition: var(--transition);
}

/* ==========================================================================
   Hero Section
   ========================================================================== */
.hero-section {
    padding: 8rem 0 6rem;
    background: linear-gradient(135deg, #3b82f6 0%, #1d4ed8 50%, #1e40af 100%);
    color: var(--text-white);
    position: relative;
    overflow: hidden;
    min-height: 100vh;
    display: flex;
    align-items: center;
}

.hero-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 20% 80%, rgba(59, 130, 246, 0.25) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(99, 102, 241, 0.2) 0%, transparent 50%),
        radial-gradient(circle at 40% 40%, rgba(14, 165, 233, 0.15) 0%, transparent 50%);
    animation: float 6s ease-in-out infinite;
}

.hero-section::after {
    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="0.05"/></pattern></defs><rect width="100" height="100" fill="url(%23grain)"/></svg>');
    opacity: 0.3;
}

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

.hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    max-width: 900px;
    margin: 0 auto;
    animation: fadeInUp 1s ease-out;
}

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

.hero-title {
    font-size: 4rem;
    font-weight: 800;
    margin-bottom: 1.5rem;
    line-height: 1.1;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    background: linear-gradient(135deg, #ffffff 0%, #e2e8f0 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.375rem;
    margin-bottom: 3rem;
    opacity: 0.95;
    line-height: 1.6;
    font-weight: 400;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.1);
}

.hero-buttons {
    display: flex;
    gap: 1.5rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 4rem;
}

.hero-buttons .btn {
    padding: 1rem 2rem;
    font-size: 1.1rem;
    font-weight: 600;
    border-radius: 0.75rem;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
}

.hero-buttons .btn-primary {
    background: linear-gradient(135deg, #ffffff 0%, #f8fafc 100%);
    color: #3b82f6;
    border: 2px solid rgba(255, 255, 255, 0.3);
}

.hero-buttons .btn-primary:hover {
    background: linear-gradient(135deg, #f8fafc 0%, #ffffff 100%);
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(255, 255, 255, 0.2);
}

.hero-buttons .btn-secondary {
    background: rgba(255, 255, 255, 0.15);
    color: var(--text-white);
    border: 2px solid rgba(255, 255, 255, 0.3);
    backdrop-filter: blur(10px);
}

.hero-buttons .btn-secondary:hover {
    background: rgba(255, 255, 255, 0.25);
    border-color: rgba(255, 255, 255, 0.4);
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(255, 255, 255, 0.15);
}

.hero-image {
    margin-top: 2rem;
    display: flex;
    justify-content: center;
    animation: fadeInUp 1s ease-out 0.3s both;
}

.code-animation {
    background: rgba(0, 0, 0, 0.4);
    border-radius: 1rem;
    padding: 2.5rem;
    font-family: var(--font-mono);
    font-size: 1rem;
    max-width: 600px;
    backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
    position: relative;
    overflow: hidden;
}

.code-animation::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
    animation: scan 2s linear infinite;
}

@keyframes scan {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

.code-line {
    margin-bottom: 0.75rem;
    opacity: 0;
    animation: typewriter 1s ease-in-out forwards;
    color: #e2e8f0;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.1);
}

.code-line:nth-child(1) { 
    animation-delay: 0.5s; 
    color: #60a5fa;
}
.code-line:nth-child(2) { 
    animation-delay: 1.5s; 
    color: #a3bffa;
}
.code-line:nth-child(3) { 
    animation-delay: 2.5s; 
    color: #34d399;
}

@keyframes typewriter {
    to {
        opacity: 1;
    }
}

/* Floating elements for visual interest */
.hero-section .floating-element {
    position: absolute;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.15);
    backdrop-filter: blur(10px);
    animation: float 6s ease-in-out infinite;
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.hero-section .floating-element:nth-child(1) {
    width: 80px;
    height: 80px;
    top: 20%;
    left: 10%;
    animation-delay: 0s;
    background: rgba(255, 255, 255, 0.12);
    border-color: rgba(255, 255, 255, 0.25);
}

.hero-section .floating-element:nth-child(2) {
    width: 120px;
    height: 120px;
    top: 60%;
    right: 15%;
    animation-delay: 2s;
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.2);
}

.hero-section .floating-element:nth-child(3) {
    width: 60px;
    height: 60px;
    bottom: 20%;
    left: 20%;
    animation-delay: 4s;
    background: rgba(255, 255, 255, 0.13);
    border-color: rgba(255, 255, 255, 0.22);
}

/* ==========================================================================
   Solutions Section
   ========================================================================== */
.solutions-section {
    padding: var(--section-padding);
    background-color: var(--bg-secondary);
}

.solutions-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: var(--grid-gap);
    margin-top: 3rem;
}

.solution-card {
    background-color: var(--bg-card);
    border-radius: 1rem;
    padding: 2rem;
    border: 1px solid var(--border-color);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.solution-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary-color);
}

.solution-card.featured {
    border: 2px solid var(--primary-color);
    box-shadow: var(--shadow-lg);
}

.solution-card.featured::before {
    content: '인기';
    position: absolute;
    top: 1rem;
    right: 1rem;
    background-color: var(--primary-color);
    color: var(--text-white);
    padding: 0.25rem 0.75rem;
    border-radius: 1rem;
    font-size: 0.75rem;
    font-weight: 600;
}

.solution-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
    display: block;
}

.solution-card h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.solution-desc {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    font-size: 1rem;
}

.feature-list {
    list-style: none;
    margin-bottom: 1.5rem;
}

.feature-list li {
    padding: 0.25rem 0;
    color: var(--text-secondary);
    position: relative;
    padding-left: 1.5rem;
}

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

.solution-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
}

.tech-tag {
    background-color: var(--bg-secondary);
    color: var(--text-secondary);
    padding: 0.25rem 0.75rem;
    border-radius: 1rem;
    font-size: 0.8rem;
    font-weight: 500;
}

/* ==========================================================================
   Features Section
   ========================================================================== */
.features-section {
    padding: var(--section-padding);
    background-color: var(--bg-primary);
}

.features-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.features-text h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 2rem;
    color: var(--text-primary);
}

.feature-item {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    align-items: flex-start;
}

.feature-icon {
    font-size: 1.5rem;
    margin-top: 0.25rem;
    flex-shrink: 0;
}

.feature-item h4 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

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

.stats-card {
    background-color: var(--bg-card);
    border-radius: 1rem;
    padding: 2rem;
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border-color);
}

.stat {
    text-align: center;
    margin-bottom: 2rem;
}

.stat:last-child {
    margin-bottom: 0;
}

.stat-number {
    font-size: 3rem;
    font-weight: 800;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.stat-label {
    color: var(--text-secondary);
    font-weight: 500;
}

/* ==========================================================================
   Technology Section
   ========================================================================== */
.tech-section {
    padding: var(--section-padding);
    background-color: var(--bg-secondary);
}

.tech-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--grid-gap);
    margin-top: 3rem;
}

.tech-category {
    background-color: var(--bg-card);
    border-radius: 1rem;
    padding: 2rem;
    border: 1px solid var(--border-color);
    text-align: center;
}

.tech-category h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.tech-items {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.tech-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem;
    background-color: var(--bg-secondary);
    border-radius: 0.5rem;
    transition: var(--transition);
}

.tech-item:hover {
    background-color: var(--primary-color);
    color: var(--text-white);
    transform: translateX(5px);
}

.tech-icon {
    font-size: 1.25rem;
}

/* ==========================================================================
   Solution Pages Common Styles  
   ========================================================================== */
/* Solution-specific styles */
.solution-hero {
    padding: 8rem 0 6rem;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.solution-hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.solution-badge {
    display: inline-block;
    background: rgba(255, 255, 255, 0.2);
    padding: 0.5rem 1rem;
    border-radius: 2rem;
    font-size: 0.9rem;
    margin-bottom: 1rem;
}

.solution-hero h1 {
    font-size: 3.5rem;
    font-weight: 800;
    margin-bottom: 1rem;
}

.version {
    font-size: 1.5rem;
    opacity: 0.8;
    font-weight: 400;
}

.solution-tagline {
    font-size: 1.25rem;
    margin-bottom: 2rem;
    opacity: 0.9;
    line-height: 1.5;
}

.solution-stats {
    display: flex;
    gap: 2rem;
    margin-bottom: 2rem;
}

.solution-actions {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.terminal-window {
    background: #1e1e1e;
    border-radius: 0.5rem;
    overflow: hidden;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
}

.terminal-header {
    background: #2d2d2d;
    padding: 1rem;
    display: flex;
    align-items: center;
    gap: 1rem;
}

.terminal-controls {
    display: flex;
    gap: 0.5rem;
}

.control {
    width: 12px;
    height: 12px;
    border-radius: 50%;
}

.control.red { background: #ff5f56; }
.control.yellow { background: #ffbd2e; }
.control.green { background: #27ca3f; }

.terminal-title {
    color: #fff;
    font-weight: 500;
}

.terminal-content {
    padding: 1.5rem;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.9rem;
    color: #00ff00;
}

.terminal-line {
    margin-bottom: 0.5rem;
    opacity: 0;
    animation: typewriter 1s ease-in-out forwards;
}

.terminal-line:nth-child(1) { animation-delay: 0.5s; }
.terminal-line:nth-child(2) { animation-delay: 1.5s; }
.terminal-line:nth-child(3) { animation-delay: 2.5s; }
.terminal-line:nth-child(4) { animation-delay: 3.5s; }
.terminal-line:nth-child(5) { animation-delay: 4.5s; }

.features-showcase {
    padding: 5rem 0;
    background: var(--bg-secondary);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.feature-card {
    background: var(--bg-card);
    border-radius: 1rem;
    padding: 2rem;
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.feature-card.featured {
    border: 2px solid var(--primary-color);
    box-shadow: var(--shadow-lg);
}

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

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

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

.feature-details {
    list-style: none;
    padding: 0;
    margin-top: 1rem;
}

.feature-details li {
    padding: 0.25rem 0;
    color: var(--text-secondary);
    position: relative;
    padding-left: 1.5rem;
}

.feature-details li::before {
    content: '▸';
    position: absolute;
    left: 0;
    color: var(--primary-color);
}

.tech-specs {
    padding: 5rem 0;
    background: var(--bg-primary);
}

.specs-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.spec-category {
    background: var(--bg-card);
    border-radius: 1rem;
    padding: 2rem;
    border: 1px solid var(--border-color);
}

.spec-category h3 {
    font-size: 1.25rem;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
    text-align: center;
}

.spec-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--border-color);
}

.spec-item:last-child {
    border-bottom: none;
}

.spec-label {
    font-weight: 500;
    color: var(--text-secondary);
}

.spec-value {
    font-weight: 600;
    color: var(--text-primary);
}

.code-examples {
    padding: 5rem 0;
    background: var(--bg-secondary);
}

.example-tabs {
    margin-top: 3rem;
}

.tab-nav {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 2rem;
    border-bottom: 2px solid var(--border-color);
}

.tab-btn {
    padding: 1rem 2rem;
    border: none;
    background: transparent;
    color: var(--text-secondary);
    font-weight: 500;
    cursor: pointer;
    border-bottom: 2px solid transparent;
    transition: var(--transition);
}

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

.tab-content {
    display: none;
}

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

.code-block {
    background: #1e1e1e;
    border-radius: 0.5rem;
    overflow: hidden;
    margin-bottom: 2rem;
}

.code-header {
    background: #2d2d2d;
    padding: 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.code-lang {
    color: #fff;
    font-weight: 500;
}

.copy-btn {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 0.25rem;
    cursor: pointer;
    font-size: 0.875rem;
}

.code-block pre {
    margin: 0;
    padding: 1.5rem;
    overflow-x: auto;
}

.code-block code {
    color: #f8f8f2;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.9rem;
    line-height: 1.5;
}

.download-section {
    padding: 5rem 0;
    background: var(--bg-primary);
}

.download-options {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 2rem;
    margin-top: 3rem;
}

.download-card {
    background: var(--bg-card);
    border-radius: 1rem;
    padding: 2rem;
    border: 1px solid var(--border-color);
}

.download-card.featured {
    border: 2px solid var(--primary-color);
    box-shadow: var(--shadow-lg);
}

.download-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.download-badge {
    background: var(--primary-color);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 1rem;
    font-size: 0.8rem;
    font-weight: 600;
}

.version-info {
    margin-bottom: 1rem;
}

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

.version-features {
    list-style: none;
    padding: 0;
    margin-bottom: 2rem;
}

.version-features li {
    padding: 0.25rem 0;
    color: var(--text-secondary);
    position: relative;
    padding-left: 1.5rem;
}

.version-features li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--success-color);
    font-weight: bold;
}

.download-actions {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.system-requirements {
    margin-top: 4rem;
    background: var(--bg-secondary);
    padding: 2rem;
    border-radius: 1rem;
}

.requirements-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-top: 1.5rem;
}

.requirement-item {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.requirement-item strong {
    color: var(--text-primary);
    font-weight: 600;
}

.requirement-item span {
    color: var(--text-secondary);
}

.documentation-section {
    padding: 5rem 0;
    background: var(--bg-secondary);
}

.docs-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.doc-card {
    background: var(--bg-card);
    border-radius: 1rem;
    padding: 2rem;
    border: 1px solid var(--border-color);
    text-align: center;
    transition: var(--transition);
}

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

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

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

.doc-card p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    line-height: 1.5;
}

/* Solution Pages Responsive adjustments */
@media (max-width: 768px) {
    .solution-hero-content {
        grid-template-columns: 1fr;
        gap: 2rem;
        text-align: center;
    }
    
    .solution-hero h1 {
        font-size: 2.5rem;
    }
    
    .solution-stats {
        justify-content: center;
    }
    
    .download-options {
        grid-template-columns: 1fr;
    }
    
    .tab-nav {
        flex-wrap: wrap;
    }
    
    .tab-btn {
        padding: 0.75rem 1rem;
        font-size: 0.9rem;
    }
}

/* ==========================================================================
   SQL2Excel Specific Styles
   ========================================================================== */
/* Excel-specific hero styling */
.excel-hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

/* Excel preview styling */
.excel-preview {
    background: white;
    border-radius: 0.5rem;
    overflow: hidden;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
    border: 1px solid #e5e7eb;
}

.excel-header {
    background: #f3f4f6;
    border-bottom: 1px solid #d1d5db;
}

.excel-tabs {
    display: flex;
    padding: 0.5rem;
    gap: 0.25rem;
}

.excel-tab {
    padding: 0.5rem 1rem;
    background: #e5e7eb;
    border-radius: 0.25rem 0.25rem 0 0;
    font-size: 0.875rem;
    color: #374151;
    border: 1px solid #d1d5db;
    border-bottom: none;
    cursor: pointer;
    transition: var(--transition);
}

.excel-tab.active {
    background: white;
    color: #059669;
    font-weight: 600;
}

.excel-content {
    background: white;
    padding: 1rem;
}

.excel-row {
    display: grid;
    grid-template-columns: 50px 200px 100px 250px;
    gap: 1px;
    margin-bottom: 1px;
}

.excel-row.header {
    background: #4f81bd;
    color: white;
    font-weight: 600;
}

.excel-row.header .excel-cell {
    background: #4f81bd;
    color: white;
    text-align: center;
    padding: 0.75rem 0.5rem;
}

.excel-cell {
    background: #ffffcc;
    padding: 0.5rem;
    border: 1px solid #d1d5db;
    font-size: 0.875rem;
    display: flex;
    align-items: center;
}

.excel-cell.link {
    color: #2563eb;
    cursor: pointer;
}

.excel-cell.link:hover {
    text-decoration: underline;
}

/* Excel features section */
.excel-features {
    padding: 5rem 0;
    background: var(--bg-primary);
}

.excel-features-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    margin-top: 3rem;
}

.excel-feature-demo h3 {
    font-size: 1.5rem;
    margin-bottom: 2rem;
    color: var(--text-primary);
}

.style-preview {
    background: var(--bg-card);
    border-radius: 1rem;
    padding: 2rem;
    border: 1px solid var(--border-color);
}

.style-section {
    margin-bottom: 2rem;
}

.style-section:last-child {
    margin-bottom: 0;
}

.style-section h4 {
    font-size: 1.125rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.style-example {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1px;
    margin-bottom: 1rem;
    border: 1px solid var(--border-color);
    overflow: hidden;
    border-radius: 0.25rem;
}

.style-example.header-style .cell {
    background: #4f81bd;
    color: white;
    font-weight: 600;
    text-align: center;
}

.style-example.data-style .cell {
    background: #ffffcc;
    color: #000;
}

.style-example .cell {
    padding: 0.75rem 0.5rem;
    font-size: 0.875rem;
    border-right: 1px solid var(--border-color);
}

.style-example .cell:last-child {
    border-right: none;
}

.style-specs {
    font-size: 0.875rem;
    color: var(--text-secondary);
    font-style: italic;
}

.excel-feature-list h3 {
    font-size: 1.5rem;
    margin-bottom: 2rem;
    color: var(--text-primary);
}

.style-categories {
    display: grid;
    gap: 2rem;
}

.style-category {
    background: var(--bg-secondary);
    border-radius: 0.5rem;
    padding: 1.5rem;
}

.style-category h4 {
    font-size: 1.125rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.style-category ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.style-category li {
    padding: 0.25rem 0;
    color: var(--text-secondary);
    position: relative;
    padding-left: 1.5rem;
}

.style-category li::before {
    content: '▸';
    position: absolute;
    left: 0;
    color: var(--success-color);
}

/* SQL2Excel Responsive adjustments */
/* Animations */
@keyframes typewriter {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@media (max-width: 768px) {
    .excel-features-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .excel-row {
        grid-template-columns: 40px 120px 80px 150px;
        font-size: 0.75rem;
    }
    
    .excel-cell {
        padding: 0.375rem 0.25rem;
        font-size: 0.75rem;
    }
    
    .style-example {
        grid-template-columns: repeat(2, 1fr);
        gap: 1px;
    }
    
    .style-categories {
        gap: 1rem;
    }
}

/* ==========================================================================
   Contact Section
   ========================================================================== */
.contact-section {
    padding: var(--section-padding);
    background-color: var(--bg-primary);
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 4rem;
    margin-top: 3rem;
}

.contact-info h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 2rem;
    color: var(--text-primary);
}

.contact-item {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    align-items: flex-start;
}

.contact-icon {
    font-size: 1.5rem;
    margin-top: 0.25rem;
    flex-shrink: 0;
}

.contact-form {
    background-color: var(--bg-card);
    border-radius: 1rem;
    padding: 2rem;
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-md);
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--text-primary);
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    font-family: inherit;
    font-size: 1rem;
    transition: var(--transition);
    background-color: var(--bg-primary);
    color: var(--text-primary);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

/* ==========================================================================
   Footer
   ========================================================================== */
.footer {
    background-color: var(--bg-dark);
    color: var(--text-white);
    padding: 3rem 0 1rem;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 3rem;
    margin-bottom: 2rem;
}

.footer-brand {
    display: flex;
    align-items: center;
    margin-bottom: 1rem;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
}

.footer-brand .brand-icon {
    font-size: 1.5rem;
    margin-right: 0.5rem;
    background: linear-gradient(135deg, #3b82f6 0%, #1d4ed8 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    filter: drop-shadow(0 2px 4px rgba(59, 130, 246, 0.2));
}

.footer-desc {
    color: #cbd5e1;
    line-height: 1.6;
    margin-bottom: 1.5rem;
}

.social-links {
    display: flex;
    gap: 1rem;
}

.social-link {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 2.5rem;
    height: 2.5rem;
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    transition: var(--transition);
    font-size: 1.25rem;
}

.social-link:hover {
    background-color: var(--primary-color);
    transform: translateY(-2px);
}

.footer-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-white);
}

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

.footer-links li {
    margin-bottom: 0.5rem;
}

.footer-links a {
    color: #cbd5e1;
    transition: var(--transition);
}

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

.contact-info .contact-item {
    margin-bottom: 1.5rem;
}

.contact-info strong {
    color: var(--text-white);
}

.footer-bottom {
    border-top: 1px solid #374151;
    padding-top: 2rem;
}

.footer-bottom-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.copyright p {
    color: #9ca3af;
    margin-bottom: 0.25rem;
}

.version-info {
    font-size: 0.875rem;
}

.update-date {
    color: var(--accent-color);
}

.footer-legal {
    display: flex;
    gap: 1rem;
    align-items: center;
}

.footer-legal a {
    color: #cbd5e1;
    font-size: 0.875rem;
    transition: var(--transition);
}

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

.separator {
    color: #6b7280;
}

/* ==========================================================================
   Back to Top Button
   ========================================================================== */
.back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 3rem;
    height: 3rem;
    background-color: var(--primary-color);
    color: var(--text-white);
    border: none;
    border-radius: 50%;
    cursor: pointer;
    font-size: 1.25rem;
    font-weight: bold;
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: var(--transition);
    z-index: 1000;
    box-shadow: var(--shadow-lg);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    background-color: var(--primary-hover);
    transform: translateY(-3px);
}

/* Mobile-specific styles */
@media (max-width: 768px) {
    /* Hide Excel demo on mobile for SQL2Excel pages */
    .excel-hero .solution-hero-demo,
    .solution-hero .solution-hero-demo,
    .solution-hero-demo,
    .excel-preview {
        display: none !important;
        visibility: hidden !important;
    }
    
    /* Adjust hero content layout for mobile when demo is hidden */
    .excel-hero .solution-hero-content,
    .solution-hero .solution-hero-content {
        grid-template-columns: 1fr !important;
        display: block !important;
        text-align: center;
    }
    
    .excel-hero .solution-hero-text,
    .solution-hero .solution-hero-text {
        max-width: 100% !important;
        margin: 0 auto;
        width: 100%;
    }
    
}