/* ============================================
   CSS Variables & Color System
   ============================================ */
:root {
    --color-primary: #6366f1;
    --color-primary-dark: #4f46e5;
    --color-secondary: #ec4899;
    --color-bg-dark: #0f172a;
    --color-bg-darker: #020617;
    --color-text-light: #f1f5f9;
    --color-text-muted: #cbd5e1;
    --color-border: #334155;
    --color-success: #10b981;
    --color-error: #ef4444;
    --color-info: #3b82f6;
    
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    
    --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    --font-mono: "Courier New", monospace;
    
    --border-radius: 0.5rem;
    --border-radius-lg: 1rem;
    
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    
    --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);
}

/* ============================================
   Global Styles
   ============================================ */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    background-color: var(--color-bg-dark);
    color: var(--color-text-light);
    line-height: 1.6;
    font-size: 16px;
}

<style>
/* ============================================
   Tools Section
   ============================================ */
.tools-section {
    padding: var(--spacing-2xl) var(--spacing-lg);
    max-width: 1280px;
    margin: 0 auto;
}

.tools-header {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
}

.tools-label {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: var(--color-primary);
    background: rgba(99, 102, 241, 0.1);
    border: 1px solid rgba(99, 102, 241, 0.25);
    padding: 0.35rem 0.9rem;
    border-radius: 999px;
    margin-bottom: var(--spacing-md);
}

.tools-header h2 {
    margin-bottom: var(--spacing-sm);
}

.tools-subtitle {
    font-size: 1.1rem;
    color: var(--color-text-muted);
    max-width: 520px;
    margin: 0 auto;
}

/* Filter buttons */
.tools-filter {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    justify-content: center;
    margin-bottom: var(--spacing-xl);
}

.filter-btn {
    padding: 0.45rem 1.1rem;
    background: transparent;
    border: 1px solid var(--color-border);
    border-radius: 999px;
    color: var(--color-text-muted);
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

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

.filter-btn.active {
    background: var(--color-primary);
    border-color: var(--color-primary);
    color: #fff;
    box-shadow: 0 0 16px rgba(99, 102, 241, 0.35);
}

/* Grid */
.tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-2xl);
}

/* Category cards */
.tool-category {
    background: var(--color-bg-darker);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-lg);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.tool-category::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--color-primary), var(--color-secondary));
    opacity: 0;
    transition: var(--transition);
}

.tool-category:hover {
    border-color: rgba(99, 102, 241, 0.4);
    transform: translateY(-3px);
    box-shadow: 0 12px 32px rgba(0, 0, 0, 0.3), 0 0 0 1px rgba(99, 102, 241, 0.1);
}

.tool-category:hover::before {
    opacity: 1;
}

/* Hidden state for filtering */
.tool-category.hidden {
    display: none;
}

.category-header {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: var(--spacing-md);
    flex-wrap: wrap;
}

.category-icon {
    font-size: 1.5rem;
    flex-shrink: 0;
    line-height: 1;
}

.category-header h3 {
    font-size: 1rem;
    font-weight: 700;
    color: var(--color-text-light);
    margin: 0;
    flex: 1;
    min-width: 0;
}

.category-count {
    font-size: 0.7rem;
    font-weight: 700;
    letter-spacing: 0.05em;
    color: var(--color-primary);
    background: rgba(99, 102, 241, 0.12);
    border: 1px solid rgba(99, 102, 241, 0.2);
    padding: 0.2rem 0.55rem;
    border-radius: 999px;
    white-space: nowrap;
    flex-shrink: 0;
}

/* Tool list */
.tool-list {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
}

.tool-item {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    font-size: 0.875rem;
    color: var(--color-text-muted);
    padding: 0.4rem 0.6rem;
    border-radius: 0.375rem;
    cursor: default;
    transition: background 0.15s, color 0.15s;
}

.tool-item:hover {
    background: rgba(99, 102, 241, 0.07);
    color: var(--color-text-light);
}

.tool-dot {
    width: 5px;
    height: 5px;
    border-radius: 50%;
    background: var(--color-primary);
    flex-shrink: 0;
    opacity: 0.6;
    transition: opacity 0.15s, transform 0.15s;
}

.tool-item:hover .tool-dot {
    opacity: 1;
    transform: scale(1.4);
}

/* Stats bar */
.tools-stats {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xl);
    padding: var(--spacing-lg) var(--spacing-xl);
    background: var(--color-bg-darker);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius-lg);
}

.stat-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.25rem;
}

.stat-number {
    font-size: 2rem;
    font-weight: 800;
    color: var(--color-text-light);
    background: linear-gradient(135deg, var(--color-text-light) 0%, var(--color-primary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1;
}

.stat-label {
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--color-text-muted);
}

.stat-divider {
    width: 1px;
    height: 40px;
    background: var(--color-border);
}

/* Responsive */
@media (max-width: 768px) {
    .tools-grid {
        grid-template-columns: 1fr;
    }

    .tools-stats {
        gap: var(--spacing-lg);
        padding: var(--spacing-md);
    }

    .stat-number {
        font-size: 1.5rem;
    }

    .tools-filter {
        gap: 0.4rem;
    }

    .filter-btn {
        font-size: 0.78rem;
        padding: 0.4rem 0.85rem;
    }
}

@media (max-width: 480px) {
    .tools-stats {
        flex-direction: column;
        gap: var(--spacing-md);
    }

    .stat-divider {
        width: 40px;
        height: 1px;
    }
}
</style>

/* ============================================
   Typography
   ============================================ */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: var(--spacing-md);
}

h1 {
    font-size: 3.5rem;
    letter-spacing: -0.02em;
}

h2 {
    font-size: 2.25rem;
    letter-spacing: -0.01em;
}

h3 {
    font-size: 1.5rem;
}

h4 {
    font-size: 1.25rem;
}

h5 {
    font-size: 1.125rem;
}

h6 {
    font-size: 1rem;
}

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

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

a:hover {
    color: var(--color-secondary);
}

/* ============================================
   Buttons
   ============================================ */
.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--border-radius-lg);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    white-space: nowrap;
    text-decoration: none;
}

.btn-primary {
    background-color: var(--color-primary);
    color: white;
    box-shadow: 0 0 20px rgba(99, 102, 241, 0.3);
}

.btn-primary:hover {
    background-color: var(--color-primary-dark);
    box-shadow: 0 0 30px rgba(99, 102, 241, 0.5);
    transform: translateY(-2px);
}

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

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

/* ============================================
   Header
   ============================================ */
header {
    background-color: var(--color-bg-darker);
    border-bottom: 1px solid var(--color-border);
    position: sticky;
    top: 0;
    z-index: 1000;
    backdrop-filter: blur(10px);
    background-color: rgba(2, 6, 23, 0.8);
}

.header-content {
    max-width: 1280px;
    margin: 0 auto;
    padding: var(--spacing-md) var(--spacing-lg);
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: var(--spacing-lg);
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--color-text-light);
    text-decoration: none;
}

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

.logo-icon {
    font-size: 2rem;
}

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

.nav-menu a {
    color: var(--color-text-muted);
    font-weight: 500;
    transition: var(--transition);
}

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

/* ============================================
   Footer
   ============================================ */
footer {
    background-color: var(--color-bg-darker);
    border-top: 1px solid var(--color-border);
    padding: var(--spacing-2xl) var(--spacing-lg);
    margin-top: var(--spacing-2xl);
}

.footer-content {
    max-width: 1280px;
    margin: 0 auto;
}

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

.footer-section h4 {
    color: var(--color-text-light);
    margin-bottom: var(--spacing-md);
}

.footer-section ul {
    list-style: none;
}

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

.footer-section a {
    color: var(--color-text-muted);
}

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

.footer-bottom {
    border-top: 1px solid var(--color-border);
    padding-top: var(--spacing-lg);
    text-align: center;
    color: var(--color-text-muted);
    font-size: 0.875rem;
}

.footer-socials {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    margin-bottom: var(--spacing-lg);
}

.footer-socials a {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background-color: var(--color-bg-dark);
    color: var(--color-text-muted);
    transition: var(--transition);
}

.footer-socials a:hover {
    background-color: var(--color-primary);
    color: white;
}

/* ============================================
   Main Content
   ============================================ */
main {
    max-width: 1280px;
    margin: 0 auto;
}

/* ============================================
   Hero Section
   ============================================ */
.hero {
    padding: var(--spacing-2xl) var(--spacing-lg);
    text-align: center;
    min-height: 70vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--color-bg-dark) 0%, var(--color-bg-darker) 100%);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: "";
    position: absolute;
    top: -50%;
    right: -10%;
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, rgba(99, 102, 241, 0.1) 0%, transparent 70%);
    border-radius: 50%;
    pointer-events: none;
}

.hero::after {
    content: "";
    position: absolute;
    bottom: -50%;
    left: -10%;
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, rgba(236, 72, 153, 0.1) 0%, transparent 70%);
    border-radius: 50%;
    pointer-events: none;
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 800px;
}

.hero h1 {
    background: linear-gradient(135deg, var(--color-text-light) 0%, var(--color-primary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--spacing-md);
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-xl);
}

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

/* ============================================
   Features Section
   ============================================ */
.features {
    padding: var(--spacing-2xl) var(--spacing-lg);
}

.features h2 {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
}

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

.feature-card {
    padding: var(--spacing-xl);
    background-color: var(--color-bg-darker);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius-lg);
    transition: var(--transition);
    text-align: center;
}

.feature-card:hover {
    border-color: var(--color-primary);
    background-color: rgba(99, 102, 241, 0.05);
    transform: translateY(-4px);
    box-shadow: 0 0 20px rgba(99, 102, 241, 0.2);
}

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

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

.feature-card p {
    color: var(--color-text-muted);
    margin: 0;
}

/* ============================================
   Viewer Section
   ============================================ */
.viewer-section {
    padding: var(--spacing-2xl) var(--spacing-lg);
}

.viewer-section h2 {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
}

.viewer-container {
    background-color: var(--color-bg-darker);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-xl);
}

.viewer-controls {
    margin-bottom: var(--spacing-xl);
}

.input-group {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-lg);
    flex-wrap: wrap;
}

.url-input {
    flex: 1;
    min-width: 250px;
    padding: 0.75rem 1rem;
    background-color: var(--color-bg-dark);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    color: var(--color-text-light);
    font-family: var(--font-mono);
    font-size: 0.9rem;
    transition: var(--transition);
}

.url-input:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.url-input::placeholder {
    color: var(--color-text-muted);
}

.device-buttons {
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}

.device-btn {
    padding: 0.5rem 1rem;
    background-color: var(--color-bg-dark);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    color: var(--color-text-muted);
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-weight: 600;
    font-size: 0.9rem;
}

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

.device-btn.active {
    background-color: var(--color-primary);
    border-color: var(--color-primary);
    color: white;
    box-shadow: 0 0 20px rgba(99, 102, 241, 0.3);
}

.device-icon {
    font-size: 1.2rem;
}

.preview-area {
    display: flex;
    justify-content: center;
    align-items: center;
    margin: var(--spacing-xl) 0;
    min-height: 500px;
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.05) 0%, rgba(236, 72, 153, 0.05) 100%);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-lg);
    overflow-x: auto;
}

.device-frame {
    position: relative;
    background-color: var(--color-bg-dark);
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    box-shadow: 0 0 60px rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Mobile Device Frame */
.device-frame[data-device="mobile"] {
    width: 375px;
    height: 667px;
    border: 12px solid #1a1a1a;
    border-radius: 40px;
}

/* Tablet Device Frame */
.device-frame[data-device="tablet"] {
    width: 768px;
    height: 1024px;
    border: 8px solid #1a1a1a;
    border-radius: 20px;
}

/* Desktop Device Frame */
.device-frame[data-device="desktop"] {
    width: 100%;
    height: 600px;
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius-lg);
}

.device-notch {
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 150px;
    height: 25px;
    background-color: #000;
    border-radius: 0 0 20px 20px;
    z-index: 10;
    display: none;
}

.device-frame[data-device="mobile"] .device-notch {
    display: block;
}

.device-bezels {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 40px;
    background-color: #1a1a1a;
    display: none;
}

.device-frame[data-device="mobile"] .device-bezels {
    display: block;
}

#previewFrame {
    width: 100%;
    height: 100%;
    border: none;
    background-color: white;
}

.preview-info {
    text-align: center;
    padding: var(--spacing-lg);
    background-color: var(--color-bg-dark);
    border-radius: var(--border-radius);
    color: var(--color-text-muted);
}

/* ============================================
   Responsive Design
   ============================================ */
@media (max-width: 768px) {
    h1 {
        font-size: 2.5rem;
    }

    h2 {
        font-size: 1.875rem;
    }

    .hero {
        min-height: 50vh;
        padding: var(--spacing-xl) var(--spacing-md);
    }

    .cta-buttons {
        flex-direction: column;
    }

    .cta-buttons .btn {
        width: 100%;
    }

    .header-content {
        flex-direction: column;
        padding: var(--spacing-md);
    }

    .nav-menu {
        width: 100%;
        justify-content: center;
        gap: var(--spacing-md);
    }

    .features {
        padding: var(--spacing-xl) var(--spacing-md);
    }

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

    .viewer-section {
        padding: var(--spacing-xl) var(--spacing-md);
    }

    .viewer-container {
        padding: var(--spacing-lg);
    }

    .input-group {
        flex-direction: column;
    }

    .url-input {
        min-width: auto;
    }

    .preview-area {
        min-height: 400px;
        padding: var(--spacing-md);
    }

    .device-frame[data-device="mobile"] {
        width: 280px;
        height: 500px;
        border: 8px solid #1a1a1a;
    }

    .device-frame[data-device="tablet"] {
        width: 100%;
        max-width: 500px;
        height: 600px;
        border: 4px solid #1a1a1a;
    }

    .device-frame[data-device="desktop"] {
        width: 100%;
        height: 400px;
    }
}

@media (max-width: 480px) {
    :root {
        font-size: 14px;
    }

    h1 {
        font-size: 2rem;
    }

    h2 {
        font-size: 1.5rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .nav-menu {
        gap: var(--spacing-sm);
    }

    .device-frame[data-device="mobile"] {
        width: 100%;
        max-width: 280px;
    }

    .preview-area {
        min-height: 350px;
    }
}

/* ============================================
   Utility Classes
   ============================================ */
.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

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

.text-muted {
    color: var(--color-text-muted);
}

.section {
    padding: var(--spacing-2xl) var(--spacing-lg);
}