/* ================================
   CSS Variables & Reset
   ================================ */
:root {
    /* Colors */
    --primary: #2563eb;
    --primary-dark: #1e40af;
    --primary-light: #3b82f6;
    --secondary: #f97316;
    --secondary-dark: #ea580c;
    --success: #10b981;
    --danger: #ef4444;
    
    /* Neutrals */
    --dark: #0f172a;
    --dark-alt: #1e293b;
    --medium: #475569;
    --light: #cbd5e1;
    --lighter: #e2e8f0;
    --lightest: #f1f5f9;
    --white: #ffffff;
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #2563eb 0%, #7c3aed 100%);
    --gradient-secondary: linear-gradient(135deg, #f97316 0%, #fb923c 100%);
    --gradient-hero: linear-gradient(135deg, #1e293b 0%, #0f172a 100%);
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --shadow-xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
    
    /* Typography */
    --font-display: 'Outfit', sans-serif;
    --font-body: 'DM Sans', sans-serif;
    
    /* 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: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 350ms ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    font-size: 16px;
    line-height: 1.6;
    color: var(--dark);
    background-color: var(--white);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ================================
   Typography
   ================================ */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-display);
    font-weight: 700;
    line-height: 1.2;
    color: var(--dark);
}

h1 { font-size: clamp(2rem, 5vw, 3.5rem); }
h2 { font-size: clamp(1.75rem, 4vw, 2.5rem); }
h3 { font-size: clamp(1.25rem, 3vw, 1.75rem); }
h4 { font-size: 1.25rem; }

p {
    margin-bottom: var(--spacing-md);
    color: var(--medium);
}

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

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

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

.main-content {
    min-height: calc(100vh - 80px);
}

/* ================================
   Header & Navigation
   ================================ */
.header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-sm);
}

.navbar {
    padding: var(--spacing-lg) 0;
}

.nav-wrapper {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 1.25rem;
    color: var(--dark);
    font-weight: 600;
    transition: transform var(--transition-base);
}

.logo:hover {
    transform: translateY(-2px);
    color: var(--dark);
}

.logo svg {
    stroke: var(--primary);
}

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

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

.nav-link {
    font-weight: 500;
    color: var(--medium);
    padding: var(--spacing-sm) 0;
    position: relative;
    transition: color var(--transition-base);
}

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

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

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

.mobile-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-sm);
}

.mobile-toggle span {
    width: 25px;
    height: 3px;
    background: var(--dark);
    border-radius: 2px;
    transition: all var(--transition-base);
}

/* ================================
   Hero Section
   ================================ */
.hero {
    background: var(--gradient-hero);
    color: var(--white);
    padding: var(--spacing-3xl) 0;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        radial-gradient(circle at 20% 50%, rgba(37, 99, 235, 0.15) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(124, 58, 237, 0.15) 0%, transparent 50%);
    pointer-events: none;
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

.hero-title {
    color: var(--white);
    margin-bottom: var(--spacing-lg);
    animation: fadeInUp 0.6s ease;
}

.gradient-text {
    background: linear-gradient(135deg, #60a5fa 0%, #a78bfa 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--lighter);
    margin-bottom: var(--spacing-2xl);
    animation: fadeInUp 0.6s ease 0.2s both;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: var(--spacing-3xl);
    animation: fadeInUp 0.6s ease 0.4s both;
}

.stat {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 2rem;
    font-weight: 800;
    font-family: var(--font-display);
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    display: block;
    font-size: 0.875rem;
    color: var(--light);
    margin-top: var(--spacing-xs);
}

/* ================================
   Tools Section
   ================================ */
.tools-section {
    padding: var(--spacing-3xl) 0;
    background: linear-gradient(to bottom, var(--white) 0%, var(--lightest) 100%);
}

.section-title {
    text-align: center;
    margin-bottom: var(--spacing-3xl);
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 80px;
    height: 4px;
    background: var(--gradient-primary);
    margin: var(--spacing-md) auto 0;
    border-radius: 2px;
}

.tool-card {
    background: var(--white);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow);
    margin-bottom: var(--spacing-xl);
    overflow: hidden;
    transition: all var(--transition-base);
    animation: fadeIn 0.6s ease;
}

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

.tool-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
    padding: var(--spacing-xl);
    background: linear-gradient(135deg, var(--lightest) 0%, var(--white) 100%);
    border-bottom: 1px solid var(--lighter);
}

.tool-icon {
    font-size: 3rem;
    width: 80px;
    height: 80px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gradient-primary);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
}

.tool-info h3 {
    margin-bottom: var(--spacing-xs);
    color: var(--dark);
}

.tool-info p {
    margin: 0;
    color: var(--medium);
}

.tool-body {
    padding: var(--spacing-xl);
}

/* ================================
   Upload Area
   ================================ */
.upload-area {
    border: 2px dashed var(--light);
    border-radius: var(--radius-lg);
    padding: var(--spacing-3xl);
    text-align: center;
    transition: all var(--transition-base);
    background: var(--lightest);
}

.upload-area.drag-over {
    border-color: var(--primary);
    background: rgba(37, 99, 235, 0.05);
    transform: scale(1.02);
}

.upload-label {
    cursor: pointer;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-md);
    transition: all var(--transition-base);
}

.upload-label:hover {
    transform: translateY(-2px);
}

.upload-label svg {
    stroke: var(--primary);
    transition: all var(--transition-base);
}

.upload-label:hover svg {
    transform: translateY(-4px);
    stroke: var(--primary-light);
}

.upload-label span {
    font-weight: 600;
    color: var(--dark);
    font-size: 1.125rem;
}

.upload-label small {
    color: var(--medium);
    font-size: 0.875rem;
}

/* ================================
   Conversion Results
   ================================ */
.conversion-result {
    animation: fadeIn 0.4s ease;
}

.preview-container {
    background: var(--lightest);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    margin-bottom: var(--spacing-lg);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 300px;
}

.preview-container canvas {
    max-width: 100%;
    height: auto;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-md);
}

.document-info {
    text-align: center;
    padding: var(--spacing-2xl);
    background: var(--lightest);
    border-radius: var(--radius-lg);
    margin-bottom: var(--spacing-lg);
}

.document-info svg {
    stroke: var(--primary);
    margin-bottom: var(--spacing-md);
}

.document-info p {
    font-weight: 600;
    color: var(--dark);
}

/* ================================
   Compression Controls
   ================================ */
.compression-controls {
    background: var(--lightest);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    margin-bottom: var(--spacing-lg);
}

.quality-slider {
    margin-bottom: var(--spacing-lg);
}

.quality-slider label {
    display: block;
    margin-bottom: var(--spacing-sm);
    font-weight: 600;
    color: var(--dark);
}

#quality-range {
    width: 100%;
    height: 8px;
    border-radius: 4px;
    background: var(--light);
    outline: none;
    -webkit-appearance: none;
}

#quality-range::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: var(--gradient-primary);
    cursor: pointer;
    box-shadow: var(--shadow);
}

#quality-range::-moz-range-thumb {
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: var(--gradient-primary);
    cursor: pointer;
    border: none;
    box-shadow: var(--shadow);
}

.size-comparison {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: var(--spacing-md);
}

.size-info {
    text-align: center;
    padding: var(--spacing-md);
    background: var(--white);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
}

.size-info span {
    display: block;
    font-size: 0.875rem;
    color: var(--medium);
    margin-bottom: var(--spacing-xs);
}

.size-info strong {
    display: block;
    font-size: 1.25rem;
    color: var(--dark);
    font-family: var(--font-display);
}

.size-info.savings strong {
    color: var(--success);
}

/* ================================
   Buttons
   ================================ */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-xl);
    border: none;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: all var(--transition-base);
    font-family: var(--font-body);
}

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

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

.btn-secondary {
    background: var(--lighter);
    color: var(--dark);
    margin-left: var(--spacing-md);
}

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

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

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

/* ================================
   Content Section
   ================================ */
.content-section {
    padding: var(--spacing-3xl) 0;
    background: var(--white);
}

.content-wrapper {
    display: grid;
    grid-template-columns: 1fr 300px;
    gap: var(--spacing-3xl);
}

.main-content article h2 {
    margin-top: var(--spacing-2xl);
    margin-bottom: var(--spacing-lg);
}

.main-content article h3 {
    margin-top: var(--spacing-xl);
    margin-bottom: var(--spacing-md);
    color: var(--dark-alt);
}

.main-content article p {
    margin-bottom: var(--spacing-lg);
    line-height: 1.8;
    color: var(--medium);
}

/* ================================
   Sidebar
   ================================ */
.sidebar {
    position: sticky;
    top: 100px;
    height: fit-content;
}

.sidebar-card {
    background: var(--lightest);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    margin-bottom: var(--spacing-lg);
    box-shadow: var(--shadow-sm);
}

.sidebar-card h4 {
    margin-bottom: var(--spacing-md);
    color: var(--dark);
}

.feature-list,
.link-list {
    list-style: none;
}

.feature-list li {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
    color: var(--medium);
}

.feature-list svg {
    stroke: var(--success);
    flex-shrink: 0;
}

.link-list li {
    margin-bottom: var(--spacing-sm);
}

.link-list a {
    color: var(--medium);
    transition: all var(--transition-base);
    display: block;
    padding: var(--spacing-sm) 0;
}

.link-list a:hover {
    color: var(--primary);
    padding-left: var(--spacing-sm);
}

.cta-card {
    background: var(--gradient-primary);
    color: var(--white);
}

.cta-card h4 {
    color: var(--white);
}

.cta-card p {
    color: rgba(255, 255, 255, 0.9);
}

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

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-xl);
    margin-top: var(--spacing-2xl);
}

.feature-card {
    background: var(--white);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    text-align: center;
    transition: all var(--transition-base);
}

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

.feature-number {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    background: var(--gradient-primary);
    color: var(--white);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 800;
    margin: 0 auto var(--spacing-lg);
    font-family: var(--font-display);
}

.feature-card h3 {
    margin-bottom: var(--spacing-md);
}

.feature-card p {
    margin: 0;
}

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

.footer-grid {
    display: grid;
    grid-template-columns: 2fr repeat(3, 1fr);
    gap: var(--spacing-2xl);
    margin-bottom: var(--spacing-2xl);
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-lg);
    font-size: 1.25rem;
}

.footer-brand svg {
    stroke: var(--primary-light);
}

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

.footer-description {
    color: var(--light);
    margin-bottom: var(--spacing-lg);
}

.social-links {
    display: flex;
    gap: var(--spacing-md);
}

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

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

.footer-title {
    color: var(--white);
    margin-bottom: var(--spacing-md);
    font-size: 1rem;
}

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

.footer-links li {
    margin-bottom: var(--spacing-sm);
}

.footer-links a {
    color: var(--light);
    transition: all var(--transition-base);
}

.footer-links a:hover {
    color: var(--white);
    padding-left: var(--spacing-xs);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: var(--spacing-lg);
    text-align: center;
}

.footer-bottom p {
    color: var(--light);
    margin-bottom: var(--spacing-sm);
}

.footer-note {
    font-size: 0.875rem;
    opacity: 0.8;
}

/* ================================
   Animations
   ================================ */
@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

/* ================================
   Responsive Design
   ================================ */
@media (max-width: 1024px) {
    .content-wrapper {
        grid-template-columns: 1fr;
    }
    
    .sidebar {
        position: static;
    }
    
    .footer-grid {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--white);
        flex-direction: column;
        padding: var(--spacing-lg);
        box-shadow: var(--shadow-lg);
    }
    
    .nav-menu.active {
        display: flex;
    }
    
    .mobile-toggle {
        display: flex;
    }
    
    .hero-stats {
        flex-direction: column;
        gap: var(--spacing-lg);
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
    }
    
    .tool-header {
        flex-direction: column;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 var(--spacing-md);
    }
    
    .tool-icon {
        width: 60px;
        height: 60px;
        font-size: 2rem;
    }
    
    .size-comparison {
        grid-template-columns: 1fr;
    }
}