/* ============================================
   Leonis Books - Modern Landing Page Styles
   ============================================ */

/* CSS Custom Properties (Variables) */
:root {
    /* Colors - extracted from Leonis branding */
    --color-primary: #1a5f7a;
    --color-primary-dark: #134b61;
    --color-primary-light: #2d8ab8;
    --color-secondary: #c9a227;
    --color-secondary-dark: #a3821a;
    --color-secondary-light: #e6c74d;

    /* Neutrals */
    --color-white: #ffffff;
    --color-off-white: #f8f9fa;
    --color-gray-100: #f1f3f4;
    --color-gray-200: #e8eaed;
    --color-gray-300: #dadce0;
    --color-gray-400: #bdc1c6;
    --color-gray-500: #80868b;
    --color-gray-600: #5f6368;
    --color-gray-700: #3c4043;
    --color-gray-800: #202124;
    --color-gray-900: #1a1a1a;

    /* Semantic colors */
    --color-success: #188038;
    --color-error: #d93025;
    --color-warning: #f9ab00;

    /* Typography */
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.9rem;
    --font-size-base: 1.05rem;
    --font-size-lg: 1.2rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 1.875rem;
    --font-size-4xl: 2.25rem;
    --font-size-5xl: 3rem;

    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --spacing-3xl: 4rem;

    /* Border radius */
    --radius-sm: 0.25rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-full: 9999px;

    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.15);

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 350ms ease;

    /* Layout */
    --container-max: 1200px;
    --header-height: 77px;
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: var(--header-height);
}

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--color-gray-800);
    background-color: var(--color-white);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

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

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

ul, ol {
    list-style: none;
}

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

/* Container */
.container {
    width: 100%;
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

/* ============================================
   Header & Navigation
   ============================================ */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    background: var(--color-white);
    box-shadow: var(--shadow-md);
    z-index: 1000;
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 1.35rem;
    font-weight: 700;
    color: var(--color-gray-800);
}

.logo-image {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-full);
    object-fit: cover;
}

.logo-text {
    color: var(--color-primary);
}

.nav-list {
    display: flex;
    gap: var(--spacing-xl);
}

.nav-link {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--color-gray-600);
    transition: color var(--transition-fast);
}

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

/* Mobile Navigation Toggle */
.nav-toggle {
    display: none;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    width: 44px;
    height: 44px;
    padding: var(--spacing-sm);
}

.hamburger {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--color-gray-700);
    position: relative;
    transition: background var(--transition-fast);
}

.hamburger::before,
.hamburger::after {
    content: '';
    position: absolute;
    left: 0;
    width: 24px;
    height: 2px;
    background: var(--color-gray-700);
    transition: transform var(--transition-fast);
}

.hamburger::before {
    top: -7px;
}

.hamburger::after {
    bottom: -7px;
}

.nav-toggle[aria-expanded="true"] .hamburger {
    background: transparent;
}

.nav-toggle[aria-expanded="true"] .hamburger::before {
    transform: rotate(45deg) translate(5px, 5px);
}

.nav-toggle[aria-expanded="true"] .hamburger::after {
    transform: rotate(-45deg) translate(5px, -5px);
}

/* ============================================
   Hero Section
   ============================================ */
.hero {
    position: relative;
    padding: calc(var(--header-height) + var(--spacing-3xl)) 0 var(--spacing-3xl);
    background: linear-gradient(135deg, var(--color-off-white) 0%, var(--color-gray-100) 100%);
    overflow: hidden;
}

.hero-background {
    position: absolute;
    inset: 0;
    background:
        radial-gradient(circle at 20% 80%, rgba(26, 95, 122, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(201, 162, 39, 0.1) 0%, transparent 50%);
    pointer-events: none;
}

.hero-content {
    position: relative;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-3xl);
    align-items: center;
}

.hero-title {
    font-size: var(--font-size-5xl);
    font-weight: 800;
    line-height: 1.1;
    color: var(--color-gray-900);
    margin-bottom: var(--spacing-lg);
}

.hero-title-line1 {
    display: block;
}

.hero-title-line2 {
    display: block;
    color: var(--color-primary);
}

.hero-subtitle {
    font-size: var(--font-size-lg);
    color: var(--color-gray-600);
    margin-bottom: var(--spacing-xl);
    line-height: 1.7;
}

.hero-cta {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-xl);
    flex-wrap: wrap;
}

.hero-badges {
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}

.badge {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-xs) var(--spacing-sm);
    background: var(--color-white);
    border: 1px solid var(--color-gray-200);
    border-radius: var(--radius-full);
    font-size: var(--font-size-xs);
    font-weight: 500;
    color: var(--color-gray-600);
}

.badge svg {
    width: 14px;
    height: 14px;
}

.hero-image {
    display: flex;
    justify-content: center;
}

.hero-image-frame {
    position: relative;
    background: var(--color-white);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    padding: var(--spacing-md);
    transform: perspective(1000px) rotateY(-5deg) rotateX(2deg);
    transition: transform var(--transition-slow);
}

.hero-image-frame:hover {
    transform: perspective(1000px) rotateY(0deg) rotateX(0deg);
}

.hero-screenshot {
    border-radius: var(--radius-lg);
    width: 100%;
    max-width: 500px;
}

/* ============================================
   Buttons
   ============================================ */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-lg);
    font-size: var(--font-size-sm);
    font-weight: 600;
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
    text-decoration: none;
}

.btn-icon {
    width: 18px;
    height: 18px;
}

.btn-icon-right {
    width: 18px;
    height: 18px;
}

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

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

.btn-secondary {
    background: var(--color-white);
    color: var(--color-gray-700);
    border: 1px solid var(--color-gray-300);
}

.btn-secondary:hover {
    background: var(--color-gray-100);
    color: var(--color-gray-800);
}

.btn-full {
    width: 100%;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* ============================================
   Section Styles
   ============================================ */
.section-header {
    text-align: center;
    margin-bottom: var(--spacing-3xl);
}

.section-title {
    font-size: var(--font-size-3xl);
    font-weight: 700;
    color: var(--color-gray-900);
    margin-bottom: var(--spacing-sm);
}

.section-subtitle {
    font-size: var(--font-size-lg);
    color: var(--color-gray-600);
}

/* ============================================
   Features Section
   ============================================ */
.features {
    padding: var(--spacing-3xl) 0;
    background: var(--color-white);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-xl);
}

.feature-card {
    padding: var(--spacing-xl);
    background: var(--color-off-white);
    border-radius: var(--radius-lg);
    transition: transform var(--transition-base), box-shadow var(--transition-base);
}

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

.feature-icon {
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-primary);
    color: var(--color-white);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-md);
}

.feature-icon svg {
    width: 24px;
    height: 24px;
}

.feature-title {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--color-gray-900);
    margin-bottom: var(--spacing-sm);
}

.feature-description {
    font-size: var(--font-size-sm);
    color: var(--color-gray-600);
    line-height: 1.7;
}

/* ============================================
   Screenshots Section
   ============================================ */
.screenshots {
    padding: var(--spacing-3xl) 0;
    background: var(--color-gray-900);
    color: var(--color-white);
}

.screenshots .section-title {
    color: var(--color-white);
}

.screenshots .section-subtitle {
    color: var(--color-gray-400);
}

.screenshot-carousel {
    position: relative;
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.carousel-track {
    position: relative;
    width: 100%;
    overflow: hidden;
}

.carousel-slide {
    display: none;
    opacity: 0;
    transition: opacity var(--transition-slow);
}

.carousel-slide.active {
    display: block;
    opacity: 1;
}

.carousel-slide img {
    display: block;
    width: 100%;
    aspect-ratio: 1200 / 840;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
}

.carousel-caption {
    text-align: center;
    padding: var(--spacing-lg);
}

.carousel-caption h3 {
    font-size: var(--font-size-xl);
    margin-bottom: var(--spacing-xs);
}

.carousel-caption p {
    font-size: var(--font-size-sm);
    color: var(--color-gray-400);
}

.carousel-btn {
    flex-shrink: 0;
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-white);
    color: var(--color-gray-800);
    border-radius: var(--radius-full);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-fast);
}

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

.carousel-btn svg {
    width: 24px;
    height: 24px;
}

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

.carousel-dot {
    width: 10px;
    height: 10px;
    border-radius: var(--radius-full);
    background: var(--color-gray-600);
    transition: all var(--transition-fast);
}

.carousel-dot.active {
    background: var(--color-secondary);
    width: 30px;
    border-radius: var(--radius-full);
}

/* ============================================
   Technical Section
   ============================================ */
.technical {
    padding: var(--spacing-3xl) 0;
    background: var(--color-off-white);
}

.technical-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-xl);
}

.tech-card {
    background: var(--color-white);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
}

.tech-card.full-width {
    grid-column: 1 / -1;
}

.tech-title {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--color-gray-900);
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-sm);
    border-bottom: 2px solid var(--color-primary);
}

.tech-list {
    font-size: var(--font-size-sm);
    color: var(--color-gray-600);
    line-height: 1.8;
}

.tech-list li {
    margin-bottom: var(--spacing-xs);
}

.tech-list strong {
    color: var(--color-gray-800);
}

.code-block {
    background: var(--color-gray-900);
    border-radius: var(--radius-md);
    padding: var(--spacing-lg);
    overflow-x: auto;
}

.code-block pre {
    font-family: 'SF Mono', 'Monaco', 'Inconsolata', 'Fira Mono', monospace;
    font-size: var(--font-size-sm);
    color: var(--color-gray-300);
    line-height: 1.6;
}

.data-model-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-xl);
}

.data-category h4 {
    font-size: var(--font-size-base);
    font-weight: 600;
    color: var(--color-primary);
    margin-bottom: var(--spacing-sm);
}

.data-category ul {
    font-size: var(--font-size-sm);
    color: var(--color-gray-600);
}

.data-category li {
    padding: var(--spacing-xs) 0;
    border-bottom: 1px solid var(--color-gray-100);
}

.data-category li:last-child {
    border-bottom: none;
}

/* ============================================
   Download Section
   ============================================ */
.download {
    padding: var(--spacing-3xl) 0;
    background: var(--color-white);
}

.download-options {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-2xl);
}

.download-card {
    position: relative;
    background: var(--color-off-white);
    padding: var(--spacing-2xl);
    border-radius: var(--radius-lg);
    border: 2px solid transparent;
}

.download-card.featured {
    border-color: var(--color-primary);
    background: linear-gradient(135deg, rgba(26, 95, 122, 0.05) 0%, rgba(26, 95, 122, 0.1) 100%);
}

.download-badge {
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    background: var(--color-success);
    color: var(--color-white);
    font-size: var(--font-size-xs);
    font-weight: 600;
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-full);
}

.download-title {
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--color-gray-900);
    margin-bottom: var(--spacing-sm);
}

.download-description {
    font-size: var(--font-size-sm);
    color: var(--color-gray-600);
    margin-bottom: var(--spacing-lg);
}

.download-steps {
    margin-bottom: var(--spacing-lg);
}

.download-step {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-sm);
    font-size: var(--font-size-sm);
    color: var(--color-gray-700);
}

.step-number {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 24px;
    height: 24px;
    background: var(--color-primary);
    color: var(--color-white);
    font-size: var(--font-size-xs);
    font-weight: 600;
    border-radius: var(--radius-full);
}

.download-notice {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md);
    background: var(--color-warning);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-lg);
    font-size: var(--font-size-sm);
    color: var(--color-gray-800);
}

.download-notice svg {
    width: 20px;
    height: 20px;
    flex-shrink: 0;
}

.download-info {
    background: var(--color-gray-900);
    color: var(--color-white);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
}

.download-info h4 {
    font-size: var(--font-size-base);
    font-weight: 600;
    margin-bottom: var(--spacing-md);
}

.download-info ul {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-sm);
}

.download-info li {
    font-size: var(--font-size-sm);
    color: var(--color-gray-300);
    padding-left: var(--spacing-md);
    position: relative;
}

.download-info li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--color-success);
}

/* Installation Tabs */
.install-tabs {
    margin: var(--spacing-lg) 0;
}

.install-tab-buttons {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-lg);
    border-bottom: 2px solid var(--color-gray-200);
    padding-bottom: var(--spacing-sm);
}

.install-tab-btn {
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: var(--font-size-sm);
    font-weight: 500;
    color: var(--color-gray-600);
    background: transparent;
    border: none;
    border-radius: var(--radius-md) var(--radius-md) 0 0;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.install-tab-btn:hover {
    background: var(--color-gray-100);
    color: var(--color-primary);
}

.install-tab-btn.active {
    background: var(--color-primary);
    color: var(--color-white);
}

.install-tab-content {
    display: none;
}

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

.install-notice {
    font-size: var(--font-size-sm);
    color: var(--color-gray-600);
    font-style: italic;
    margin-bottom: var(--spacing-sm);
    padding: var(--spacing-sm);
    background: var(--color-gray-100);
    border-radius: var(--radius-sm);
    border-left: 3px solid var(--color-primary);
}

.install-collapse > summary {
    cursor: pointer;
}

.install-collapse > summary::marker {
    color: var(--color-primary);
}

/* ============================================
   About Section
   ============================================ */
.about {
    padding: var(--spacing-3xl) 0;
    background: var(--color-off-white);
}

.about-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: var(--spacing-3xl);
    align-items: center;
}

.about-text p {
    font-size: var(--font-size-base);
    color: var(--color-gray-700);
    line-height: 1.8;
    margin-bottom: var(--spacing-lg);
}

.about-text strong {
    color: var(--color-gray-900);
}

.about-stats {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.stat-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: var(--spacing-xl);
    background: var(--color-white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    text-align: center;
}

.stat-number {
    font-size: var(--font-size-3xl);
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: var(--spacing-xs);
}

.stat-label {
    font-size: var(--font-size-sm);
    color: var(--color-gray-600);
}

/* ============================================
   Footer
   ============================================ */
.footer {
    background: var(--color-gray-900);
    color: var(--color-gray-400);
    padding: var(--spacing-3xl) 0 var(--spacing-xl);
}

.footer-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: var(--spacing-3xl);
    margin-bottom: var(--spacing-2xl);
    padding-bottom: var(--spacing-2xl);
    border-bottom: 1px solid var(--color-gray-800);
}

.footer-brand {
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.footer-logo {
    width: 80px;
    height: 80px;
    border-radius: var(--radius-full);
    margin: 0 auto var(--spacing-md);
}

.footer-tagline {
    font-size: var(--font-size-sm);
    color: var(--color-gray-500);
    font-style: italic;
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-xl);
}

.footer-column h4 {
    font-size: var(--font-size-sm);
    font-weight: 600;
    color: var(--color-white);
    margin-bottom: var(--spacing-md);
}

.footer-column ul {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.footer-column a {
    font-size: var(--font-size-sm);
    color: var(--color-gray-500);
    transition: color var(--transition-fast);
}

.footer-column a:hover {
    color: var(--color-white);
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    font-size: var(--font-size-xs);
    color: var(--color-gray-600);
}

/* ============================================
   Responsive Styles
   ============================================ */
@media (max-width: 1024px) {
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-title {
        font-size: var(--font-size-4xl);
    }

    .hero-cta {
        justify-content: center;
    }

    .hero-badges {
        justify-content: center;
    }

    .hero-image-frame {
        transform: none;
        max-width: 400px;
    }

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

    .technical-grid {
        grid-template-columns: 1fr;
    }

    .data-model-grid {
        grid-template-columns: 1fr;
    }

    .download-options {
        grid-template-columns: 1fr;
    }

    .about-content {
        grid-template-columns: 1fr;
    }

    .about-stats {
        flex-direction: row;
        flex-wrap: wrap;
        justify-content: center;
    }

    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .footer-links {
        justify-items: center;
    }

    .footer-bottom {
        flex-direction: column;
        gap: var(--spacing-sm);
        text-align: center;
    }
}

@media (max-width: 768px) {
    :root {
        --header-height: 60px;
    }

    .nav {
        position: fixed;
        top: var(--header-height);
        left: 0;
        right: 0;
        background: var(--color-white);
        box-shadow: var(--shadow-lg);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all var(--transition-base);
    }

    .nav.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .nav-list {
        flex-direction: column;
        padding: var(--spacing-lg);
        gap: var(--spacing-md);
    }

    .nav-toggle {
        display: flex;
    }

    .hero {
        padding: calc(var(--header-height) + var(--spacing-2xl)) 0 var(--spacing-2xl);
    }

    .hero-title {
        font-size: var(--font-size-3xl);
    }

    .hero-cta {
        flex-direction: column;
        align-items: center;
    }

    .btn {
        width: 100%;
        justify-content: center;
    }

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

    .screenshot-carousel {
        flex-direction: column;
    }

    .carousel-btn {
        position: absolute;
        top: 50%;
        transform: translateY(-50%);
        z-index: 10;
    }

    .carousel-prev {
        left: var(--spacing-md);
    }

    .carousel-next {
        right: var(--spacing-md);
    }

    .download-info ul {
        grid-template-columns: 1fr;
    }

    .about-stats {
        flex-direction: column;
    }

    .footer-links {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }
}

@media (max-width: 480px) {
    .section-title {
        font-size: var(--font-size-2xl);
    }

    .hero-title {
        font-size: var(--font-size-2xl);
    }

    .hero-subtitle {
        font-size: var(--font-size-base);
    }
}

/* ============================================
   Animations
   ============================================ */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.animate-on-scroll {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity var(--transition-slow), transform var(--transition-slow);
}

.animate-on-scroll.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ============================================
   Utility Classes
   ============================================ */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

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

.mt-1 { margin-top: var(--spacing-md); }
.mt-2 { margin-top: var(--spacing-xl); }
.mt-3 { margin-top: var(--spacing-2xl); }
.mb-1 { margin-bottom: var(--spacing-md); }
.mb-2 { margin-bottom: var(--spacing-xl); }
.mb-3 { margin-bottom: var(--spacing-2xl); }