/* ===== CSS VARIABLES ===== */
:root {
    /* Light Mode Colors */
    --primary-color: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --secondary-color: #ec4899;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-tertiary: #f3f4f6;
    --text-primary: #111827;
    --text-secondary: #6b7280;
    --text-tertiary: #9ca3af;
    
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.15);
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 350ms ease;
}

/* Dark Mode Colors */
[data-theme="dark"] {
    --primary-color: #818cf8;
    --primary-dark: #6366f1;
    --primary-light: #a5b4fc;
    --secondary-color: #f472b6;
    
    --bg-primary: #111827;
    --bg-secondary: #1f2937;
    --bg-tertiary: #374151;
    --text-primary: #f9fafb;
    --text-secondary: #d1d5db;
    --text-tertiary: #9ca3af;
    
    --border-color: #374151;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.5);
    --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.6);
}

/* ===== RESET & BASE STYLES ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: background-color var(--transition-base), color var(--transition-base);
}

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

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

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

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
    transition: all var(--transition-fast);
}

input, textarea, select {
    font-family: inherit;
    font-size: inherit;
}

/* ===== NAVIGATION ===== */
.navbar {
    background-color: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 1000;
    backdrop-filter: blur(10px);
    background-color: rgba(255, 255, 255, 0.9);
    transition: all var(--transition-base);
}

[data-theme="dark"] .navbar {
    background-color: rgba(17, 24, 39, 0.9);
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-sm) var(--spacing-md);
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.logo i {
    font-size: 1.75rem;
}

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

.nav-menu a {
    color: var(--text-secondary);
    font-weight: 500;
    padding: var(--spacing-xs) 0;
    position: relative;
}

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

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

.nav-menu a:hover::after,
.nav-menu a.active::after {
    width: 100%;
}

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

.theme-toggle {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-md);
    background-color: var(--bg-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-primary);
    font-size: 1.2rem;
}

.theme-toggle:hover {
    background-color: var(--bg-tertiary);
    transform: rotate(15deg);
}

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    width: 40px;
    height: 40px;
    padding: 8px;
}

.mobile-menu-toggle span {
    width: 100%;
    height: 3px;
    background-color: var(--text-primary);
    border-radius: 2px;
    transition: all var(--transition-base);
}

/* ===== HERO SECTION ===== */
.hero {
    padding: var(--spacing-xl) 0;
    background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
    overflow: hidden;
}

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

.hero-content {
    animation: fadeInUp 0.8s ease;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: var(--spacing-md);
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

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

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

.feature-badge {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-xs) var(--spacing-sm);
    background-color: var(--bg-tertiary);
    border-radius: var(--radius-lg);
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-secondary);
}

.feature-badge i {
    color: var(--primary-color);
}

.cta-button {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: 1rem 2rem;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    font-weight: 600;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    transition: all var(--transition-base);
}

.cta-button:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-xl);
}

.cta-button i {
    animation: bounce 2s infinite;
}

.hero-image {
    position: relative;
    height: 400px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.floating-icon {
    position: absolute;
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: var(--radius-xl);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 2rem;
    box-shadow: var(--shadow-lg);
    animation: float 3s ease-in-out infinite;
    animation-delay: var(--delay);
}

.floating-icon:nth-child(1) {
    top: 20%;
    left: 10%;
}

.floating-icon:nth-child(2) {
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

.floating-icon:nth-child(3) {
    bottom: 20%;
    right: 10%;
}

/* ===== TOOLS SECTION ===== */
.tools-section {
    padding: var(--spacing-xl) 0;
}

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

.section-subtitle {
    text-align: center;
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-bottom: var(--spacing-xl);
}

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

.tool-card {
    background-color: var(--bg-secondary);
    border-radius: var(--radius-xl);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-base);
    animation: fadeInUp 0.6s ease;
}

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

.tool-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.75rem;
    margin-bottom: var(--spacing-md);
}

.tool-card h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
}

.tool-card p {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
}

.converter-container {
    margin-top: var(--spacing-md);
}

.upload-area {
    border: 2px dashed var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    text-align: center;
    cursor: pointer;
    transition: all var(--transition-base);
    position: relative;
}

.upload-area:hover {
    border-color: var(--primary-color);
    background-color: var(--bg-tertiary);
}

.upload-area.dragover {
    border-color: var(--primary-color);
    background-color: var(--primary-light);
    opacity: 0.8;
}

.upload-area i {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: var(--spacing-sm);
}

.upload-area p {
    color: var(--text-secondary);
    margin: 0;
}

.upload-area input[type="file"] {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    cursor: pointer;
}

.preview-area {
    margin-top: var(--spacing-md);
    display: none;
}

.preview-area.active {
    display: block;
}

.preview-item {
    background-color: var(--bg-tertiary);
    border-radius: var(--radius-md);
    padding: var(--spacing-sm);
    margin-bottom: var(--spacing-sm);
    display: flex;
    gap: var(--spacing-sm);
    align-items: center;
}

.preview-image {
    width: 60px;
    height: 60px;
    object-fit: cover;
    border-radius: var(--radius-sm);
}

.preview-info {
    flex: 1;
}

.preview-info h4 {
    font-size: 0.9rem;
    margin-bottom: 0.25rem;
}

.preview-info p {
    font-size: 0.8rem;
    color: var(--text-tertiary);
    margin: 0;
}

.preview-actions {
    display: flex;
    gap: var(--spacing-xs);
}

.btn-small {
    padding: 0.5rem 1rem;
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 500;
    transition: all var(--transition-fast);
}

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

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

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

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

.btn-danger:hover {
    background-color: #dc2626;
}

/* ===== FAQ SECTION ===== */
.faq-section {
    padding: var(--spacing-xl) 0;
    background-color: var(--bg-secondary);
}

.faq-container {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    background-color: var(--bg-primary);
    border-radius: var(--radius-lg);
    margin-bottom: var(--spacing-md);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
}

.faq-item:hover {
    box-shadow: var(--shadow-md);
}

.faq-question {
    width: 100%;
    padding: var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: none;
    border: none;
    text-align: left;
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-primary);
    cursor: pointer;
}

.faq-question i {
    transition: transform var(--transition-base);
    color: var(--primary-color);
}

.faq-item.active .faq-question i {
    transform: rotate(180deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-slow);
}

.faq-item.active .faq-answer {
    max-height: 500px;
}

.faq-answer p {
    padding: 0 var(--spacing-md) var(--spacing-md);
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ===== FOOTER ===== */
.footer {
    background-color: var(--bg-secondary);
    padding: var(--spacing-xl) 0 var(--spacing-md);
    border-top: 1px solid var(--border-color);
}

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

.footer-column h4 {
    margin-bottom: var(--spacing-md);
    font-size: 1.1rem;
    color: var(--text-primary);
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: var(--spacing-md);
}

.footer-logo i {
    font-size: 1.75rem;
}

.footer-description {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
}

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

.social-links a {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-md);
    background-color: var(--bg-tertiary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    transition: all var(--transition-base);
}

.social-links a:hover {
    background-color: var(--primary-color);
    color: white;
    transform: translateY(-3px);
}

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

.footer-column ul li {
    margin-bottom: var(--spacing-xs);
}

.footer-column ul li a {
    color: var(--text-secondary);
    transition: color var(--transition-fast);
}

.footer-column ul li a:hover {
    color: var(--primary-color);
}

.newsletter-form {
    display: flex;
    gap: var(--spacing-xs);
}

.newsletter-form input {
    flex: 1;
    padding: var(--spacing-sm);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    transition: all var(--transition-fast);
}

.newsletter-form input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.newsletter-form button {
    padding: var(--spacing-sm);
    width: 50px;
    background-color: var(--primary-color);
    color: white;
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.newsletter-form button:hover {
    background-color: var(--primary-dark);
}

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--border-color);
    color: var(--text-secondary);
}

/* ===== PAGE HEADER ===== */
.page-header {
    padding: var(--spacing-xl) 0;
    text-align: center;
    background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
    border-bottom: 1px solid var(--border-color);
}

.page-header h1 {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.page-header p {
    font-size: 1.2rem;
    color: var(--text-secondary);
}

.update-date {
    margin-top: var(--spacing-sm);
    font-size: 0.9rem;
    color: var(--text-tertiary);
}

/* ===== CONTENT SECTION ===== */
.content-section {
    padding: var(--spacing-xl) 0;
}

.content-wrapper {
    max-width: 900px;
    margin: 0 auto;
}

.content-text h2 {
    font-size: 2rem;
    margin-top: var(--spacing-xl);
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

.content-text h2:first-child {
    margin-top: 0;
}

.content-text h3 {
    font-size: 1.5rem;
    margin-top: var(--spacing-lg);
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

.content-text p {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    line-height: 1.8;
}

.content-text ul,
.content-text ol {
    margin-bottom: var(--spacing-md);
    padding-left: var(--spacing-lg);
    color: var(--text-secondary);
}

.content-text li {
    margin-bottom: var(--spacing-xs);
    line-height: 1.8;
}

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

/* ===== CONTACT PAGE ===== */
.contact-wrapper {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

.contact-info h2 {
    font-size: 2rem;
    margin-bottom: var(--spacing-md);
}

.contact-methods {
    margin: var(--spacing-lg) 0;
}

.contact-method {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
    padding: var(--spacing-md);
    background-color: var(--bg-secondary);
    border-radius: var(--radius-lg);
    transition: all var(--transition-base);
}

.contact-method:hover {
    transform: translateX(5px);
    box-shadow: var(--shadow-md);
}

.method-icon {
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.5rem;
    flex-shrink: 0;
}

.method-details h3 {
    font-size: 1.2rem;
    margin-bottom: 0.25rem;
}

.method-details p {
    color: var(--text-primary);
    margin: 0;
    font-weight: 500;
}

.method-details span {
    font-size: 0.9rem;
    color: var(--text-tertiary);
}

.contact-topics {
    list-style: none;
    padding: 0;
}

.contact-topics li {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-sm);
}

.contact-topics i {
    color: var(--success-color);
}

.contact-form-container {
    background-color: var(--bg-secondary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
}

.contact-form-container h2 {
    margin-bottom: var(--spacing-md);
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.form-group label {
    font-weight: 500;
    color: var(--text-primary);
}

.form-group input,
.form-group select,
.form-group textarea {
    padding: var(--spacing-sm);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    transition: all var(--transition-fast);
}

.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(99, 102, 241, 0.1);
}

.submit-button {
    padding: var(--spacing-sm) var(--spacing-lg);
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    border-radius: var(--radius-md);
    font-weight: 600;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    transition: all var(--transition-base);
}

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

.form-success {
    display: none;
    padding: var(--spacing-md);
    background-color: rgba(16, 185, 129, 0.1);
    border: 1px solid var(--success-color);
    border-radius: var(--radius-md);
    margin-top: var(--spacing-md);
    text-align: center;
}

.form-success.active {
    display: block;
}

.form-success i {
    font-size: 2rem;
    color: var(--success-color);
    margin-bottom: var(--spacing-sm);
}

.form-success p {
    color: var(--success-color);
    margin: 0;
}

.contact-additional {
    margin-top: var(--spacing-xl);
}

.contact-additional h2 {
    text-align: center;
    margin-bottom: var(--spacing-lg);
}

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

.info-card {
    background-color: var(--bg-secondary);
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
    text-align: center;
    transition: all var(--transition-base);
}

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

.info-card i {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: var(--spacing-sm);
}

.info-card h3 {
    font-size: 1.2rem;
    margin-bottom: var(--spacing-sm);
}

.info-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

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

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

@keyframes bounce {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-5px);
    }
}

/* ===== RESPONSIVE DESIGN ===== */
@media (max-width: 1024px) {
    .hero .container {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .hero-features {
        justify-content: center;
    }
    
    .hero-image {
        height: 300px;
    }
    
    .contact-wrapper {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 70px;
        left: -100%;
        width: 100%;
        height: calc(100vh - 70px);
        background-color: var(--bg-primary);
        flex-direction: column;
        padding: var(--spacing-lg);
        gap: var(--spacing-md);
        box-shadow: var(--shadow-lg);
        transition: left var(--transition-slow);
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .mobile-menu-toggle {
        display: flex;
    }
    
    .mobile-menu-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }
    
    .mobile-menu-toggle.active span:nth-child(2) {
        opacity: 0;
    }
    
    .mobile-menu-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -6px);
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .page-header h1 {
        font-size: 2rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .tools-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .hero-features {
        flex-direction: column;
        align-items: center;
    }
    
    .section-title {
        font-size: 1.75rem;
    }
    
    .tool-card {
        padding: var(--spacing-md);
    }
}