/* 
==============================================
TABLE OF CONTENTS
==============================================
1.  Global Styles
2.  Header
3.  Hero Section
4.  Converter Box
5.  Features Section
6.  Popular Conversions
7.  How It Works
8.  Testimonials
9.  FAQ Section
10. Footer
11. Blog
12. Article
13. Ads
14. Dark Mode
15. Responsive Styles
==============================================
*/

/* 1. Global Styles */
:root {
    --primary-color: #4a6cf7;
    --primary-light: #7b92ff;
    --secondary-color: #64748b;
    --accent-color: #ff6b6b;
    --light-color: #f8fafc;
    --dark-color: #1e293b;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    --max-width: 1200px;
    --ad-background: #f1f5f9;
    --ad-border: #e2e8f0;
    --card-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.05), 0 8px 10px -6px rgba(0, 0, 0, 0.05);
    --hover-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

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

body {
    font-family: 'Roboto', sans-serif;
    line-height: 1.6;
    color: #334155;
    background-color: #f8fafc;
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 20px;
}

a {
    text-decoration: none;
    color: var(--primary-color);
    transition: all 0.3s ease;
}

ul {
    list-style: none;
}

img {
    max-width: 100%;
}

/* 2. Header */
header {
    background-color: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.3);
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.03);
    position: sticky;
    top: 0;
    z-index: 1000;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

header.scrolled {
    background-color: rgba(255, 255, 255, 0.95);
    padding: 5px 0;
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 20px;
}

.logo a {
    display: flex;
    align-items: center;
    gap: 12px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.logo a:hover {
    transform: translateY(-1px);
}

.logo h1 {
    font-size: 24px;
    font-weight: 800;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: -0.8px;
}

nav ul {
    display: flex;
    align-items: center;
    gap: 4px;
}

nav ul li a {
    color: var(--dark-color);
    font-weight: 500;
    font-size: 14px;
    padding: 8px 16px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

nav ul li a i {
    font-size: 15px;
    opacity: 0.7;
    transition: all 0.3s ease;
}

nav ul li a:hover {
    background-color: rgba(74, 108, 247, 0.06);
    color: var(--primary-color);
    transform: translateY(-1px);
}

nav ul li a:hover i {
    opacity: 1;
    transform: scale(1.1);
}

nav ul li a.active {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    color: white;
    box-shadow: 0 10px 15px -3px rgba(74, 108, 247, 0.25);
}

nav ul li a.active i {
    color: white;
    opacity: 1;
}

/* 3. Hero Section */
.hero {
    padding: 100px 0 60px;
    background: radial-gradient(circle at top right, rgba(74, 108, 247, 0.05), transparent),
                radial-gradient(circle at bottom left, rgba(74, 108, 247, 0.03), transparent);
    text-align: center;
}

.hero h2 {
    font-size: 48px;
    font-weight: 800;
    margin-bottom: 20px;
    color: var(--dark-color);
    letter-spacing: -1.5px;
    line-height: 1.2;
}

.hero p {
    font-size: 20px;
    color: var(--secondary-color);
    max-width: 700px;
    margin: 0 auto 40px;
}

/* 4. Converter Box */
.converter-box {
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.5);
    border-radius: 24px;
    padding: 40px;
    box-shadow: var(--card-shadow);
    max-width: 900px;
    margin: 0 auto;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

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

.upload-area {
    border: 2px dashed rgba(74, 108, 247, 0.2);
    border-radius: 20px;
    padding: 60px 40px;
    background-color: rgba(74, 108, 247, 0.02);
    transition: all 0.3s ease;
    cursor: pointer;
    position: relative;
    overflow: hidden;
}

.upload-area:hover {
    border-color: var(--primary-color);
    background-color: rgba(74, 108, 247, 0.04);
}

.upload-area i {
    font-size: 56px;
    color: var(--primary-color);
    margin-bottom: 20px;
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.upload-area:hover i {
    transform: translateY(-8px) scale(1.1);
}

.upload-area p {
    margin: 5px 0;
    color: var(--secondary-color);
}

#file-upload {
    position: absolute;
    width: 0.1px;
    height: 0.1px;
    opacity: 0;
    overflow: hidden;
    z-index: -1;
}

.custom-file-upload {
    display: inline-block;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    color: white;
    padding: 14px 32px;
    border-radius: 14px;
    font-weight: 600;
    font-size: 16px;
    box-shadow: 0 10px 15px -3px rgba(74, 108, 247, 0.3);
    transition: all 0.3s ease;
    cursor: pointer;
}

.custom-file-upload:hover {
    transform: translateY(-2px);
    box-shadow: 0 15px 20px -5px rgba(74, 108, 247, 0.4);
    filter: brightness(1.1);
}

.custom-file-upload:active {
    transform: translateY(0);
}

.file-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
    width: 100%;
    max-width: 500px;
    margin: 0 auto 24px;
}

.file-item {
    display: flex;
    align-items: center;
    gap: 16px;
    background: white;
    padding: 16px;
    border-radius: 12px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
    text-align: left;
}

.file-item i {
    font-size: 24px !important;
    margin-bottom: 0 !important;
    color: var(--primary-color);
}

.file-info {
    flex: 1;
    min-width: 0;
}

.file-name {
    font-weight: 600;
    color: var(--dark-color);
    margin-bottom: 2px !important;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.file-size {
    font-size: 13px;
    color: var(--secondary-color);
    margin-bottom: 0 !important;
}

.clear-files {
    background: #fee2e2;
    color: #ef4444;
    border: none;
    padding: 10px 20px;
    border-radius: 10px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}

.clear-files:hover {
    background: #fecaca;
    transform: scale(1.05);
}

/* 4.1 Conversion Result */
.conversion-result {
    text-align: center;
    padding: 20px 0;
}

.result-header {
    margin-bottom: 24px;
}

.result-header i {
    font-size: 64px;
    color: #10b981;
    margin-bottom: 16px;
}

.result-header h3 {
    font-size: 24px;
    color: var(--dark-color);
    font-weight: 700;
}

.conversion-result p {
    font-size: 16px;
    color: var(--secondary-color);
    margin-bottom: 32px;
}

.download-btn {
    display: block;
    width: 100%;
    max-width: 300px;
    margin: 0 auto 16px;
    background: linear-gradient(135deg, #10b981, #34d399);
    color: white;
    border: none;
    padding: 16px 32px;
    font-size: 18px;
    font-weight: 700;
    border-radius: 14px;
    cursor: pointer;
    box-shadow: 0 10px 15px -3px rgba(16, 185, 129, 0.3);
    transition: all 0.3s;
}

.download-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 20px 25px -5px rgba(16, 185, 129, 0.4);
}

.convert-another {
    display: block;
    width: 100%;
    max-width: 300px;
    margin: 0 auto;
    background: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
    padding: 14px 32px;
    font-size: 16px;
    font-weight: 600;
    border-radius: 14px;
    cursor: pointer;
    transition: all 0.3s;
}

.convert-another:hover {
    background: rgba(74, 108, 247, 0.05);
    transform: translateY(-2px);
}

.conversion-options {
    display: flex;
    flex-direction: column;
    gap: 24px;
    margin-top: 32px;
}

.format-selection {
    display: flex;
    justify-content: center;
    gap: 20px;
    align-items: flex-end;
}

.from-format, .to-format {
    display: flex;
    flex-direction: column;
    text-align: left;
    flex: 1;
    max-width: 250px;
}

.from-format label, .to-format label {
    font-size: 13px;
    font-weight: 600;
    color: var(--secondary-color);
    margin-bottom: 8px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.from-format select, .to-format select {
    padding: 12px 16px;
    border: 1px solid var(--ad-border);
    border-radius: 12px;
    font-size: 15px;
    background-color: white;
    cursor: pointer;
    outline: none;
    transition: all 0.3s ease;
    width: 100%;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 24 24' stroke='%2364748b'%3E%3Cpath stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M19 9l-7 7-7-7'%3E%3C/path%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 12px center;
    background-size: 16px;
}

.from-format select:focus, .to-format select:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 4px rgba(74, 108, 247, 0.1);
}

.convert-btn {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    color: white;
    border: none;
    padding: 16px 40px;
    font-size: 18px;
    font-weight: 700;
    border-radius: 14px;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 10px 15px -3px rgba(74, 108, 247, 0.3);
    align-self: center;
    width: 100%;
    max-width: 300px;
}

.convert-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 20px 25px -5px rgba(74, 108, 247, 0.4);
    filter: brightness(1.1);
}

.convert-btn:active {
    transform: translateY(0);
}

/* 5. Features Section */
.features {
    padding: 100px 0;
    background-color: white;
}

.features h2 {
    text-align: center;
    font-size: 36px;
    font-weight: 800;
    margin-bottom: 60px;
    color: var(--dark-color);
    letter-spacing: -1px;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
}

.feature-card {
    background: white;
    padding: 40px 30px;
    border-radius: 24px;
    text-align: center;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    border: 1px solid #f1f5f9;
    box-shadow: var(--card-shadow);
}

.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--hover-shadow);
    border-color: rgba(74, 108, 247, 0.1);
}

.feature-card i {
    font-size: 40px;
    color: var(--primary-color);
    margin-bottom: 24px;
    background: rgba(74, 108, 247, 0.05);
    width: 80px;
    height: 80px;
    line-height: 80px;
    border-radius: 20px;
    transition: all 0.3s ease;
}

.feature-card:hover i {
    background: var(--primary-color);
    color: white;
    transform: rotate(10deg);
}

.feature-card h3 {
    font-size: 20px;
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--dark-color);
}

.feature-card p {
    color: var(--secondary-color);
    font-size: 15px;
}

/* 6. Popular Conversions */
.popular-conversions {
    padding: 100px 0;
}

.popular-conversions h2 {
    text-align: center;
    font-size: 36px;
    font-weight: 800;
    margin-bottom: 60px;
    color: var(--dark-color);
}

.conversion-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
}

.conversion-card {
    background: white;
    padding: 24px;
    border-radius: 20px;
    text-align: center;
    box-shadow: var(--card-shadow);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    border: 1px solid #f1f5f9;
}

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

.conversion-icons {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 12px;
    margin-bottom: 16px;
}

.from-icon, .to-icon {
    background-color: #f1f5f9;
    padding: 6px 12px;
    border-radius: 8px;
    font-weight: 700;
    font-size: 13px;
    color: var(--primary-color);
}

.conversion-card p {
    font-weight: 600;
    color: var(--dark-color);
    font-size: 15px;
}

/* 7. How It Works */
.how-it-works {
    padding: 100px 0;
    background: white;
}

.how-it-works h2 {
    text-align: center;
    font-size: 36px;
    font-weight: 800;
    margin-bottom: 60px;
    color: var(--dark-color);
}

.steps {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 40px;
    position: relative;
}

.step {
    text-align: center;
    position: relative;
    padding: 20px;
}

.step-number {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    color: white;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 24px;
    font-weight: 800;
    margin: 0 auto 24px;
    box-shadow: 0 10px 15px -3px rgba(74, 108, 247, 0.3);
    border: 4px solid white;
}

.step h3 {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--dark-color);
}

.step p {
    color: var(--secondary-color);
    font-size: 15px;
}

/* 8. Testimonials */
.testimonials {
    padding: 100px 0;
    background: linear-gradient(180deg, white 0%, #f8fafc 100%);
}

.testimonials h2 {
    text-align: center;
    font-size: 36px;
    font-weight: 800;
    margin-bottom: 60px;
    color: var(--dark-color);
}

.testimonial-slider {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.testimonial {
    background: white;
    padding: 40px;
    border-radius: 24px;
    box-shadow: var(--card-shadow);
    border: 1px solid #f1f5f9;
    transition: all 0.3s ease;
}

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

.testimonial-text {
    font-style: italic;
    color: var(--dark-color);
    font-size: 16px;
    margin-bottom: 24px;
    line-height: 1.8;
}

.testimonial-author {
    font-weight: 700;
    color: var(--primary-color);
    font-size: 15px;
}

/* 8a. Use Cases Section */
.use-cases {
    padding: 100px 0;
    background: white;
}

.use-cases h2 {
    text-align: center;
    font-size: 36px;
    font-weight: 800;
    margin-bottom: 60px;
    color: var(--dark-color);
}

.use-cases-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
}

.use-case-card {
    background: var(--light-color);
    border-radius: 16px;
    padding: 40px 30px;
    text-align: center;
    transition: all 0.3s ease;
    border: 1px solid transparent;
}

.use-case-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--hover-shadow);
    border-color: rgba(74, 108, 247, 0.15);
    background: white;
}

.use-case-card i {
    font-size: 48px;
    color: var(--primary-color);
    margin-bottom: 20px;
}

.use-case-card h3 {
    font-size: 20px;
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--dark-color);
}

.use-case-card p {
    color: var(--secondary-color);
    font-size: 15px;
    line-height: 1.7;
}

/* 8b. Supported Formats Section */
.supported-formats {
    padding: 100px 0;
    background: linear-gradient(135deg, #f8fafc 0%, #eef2ff 100%);
}

.supported-formats h2 {
    text-align: center;
    font-size: 36px;
    font-weight: 800;
    margin-bottom: 60px;
    color: var(--dark-color);
}

.formats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 24px;
}

.format-category {
    background: white;
    border-radius: 16px;
    padding: 32px 28px;
    box-shadow: var(--card-shadow);
    transition: all 0.3s ease;
    border-left: 4px solid var(--primary-color);
}

.format-category:hover {
    transform: translateY(-4px);
    box-shadow: var(--hover-shadow);
}

.format-category i {
    font-size: 36px;
    color: var(--primary-color);
    margin-bottom: 16px;
}

.format-category h3 {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 10px;
    color: var(--dark-color);
}

.format-category p {
    color: var(--secondary-color);
    font-size: 14px;
    line-height: 1.6;
}

/* 8c. Contact Page Styles */
.page-header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-light) 100%);
    padding: 80px 0;
    text-align: center;
    color: white;
    margin-bottom: 0;
}

.page-header h1 {
    font-size: 42px;
    font-weight: 800;
    margin-bottom: 10px;
}

.page-header p {
    font-size: 18px;
    opacity: 0.9;
}

.contact-section {
    padding: 80px 0;
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1.3fr;
    gap: 50px;
    align-items: start;
}

.contact-info h2 {
    font-size: 28px;
    font-weight: 800;
    margin-bottom: 20px;
    color: var(--dark-color);
}

.contact-info > p {
    color: var(--secondary-color);
    margin-bottom: 40px;
    line-height: 1.7;
}

.contact-methods {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.contact-method {
    display: flex;
    align-items: flex-start;
    gap: 20px;
    padding: 24px;
    background: var(--light-color);
    border-radius: 12px;
    transition: all 0.3s ease;
}

.contact-method:hover {
    background: white;
    box-shadow: var(--card-shadow);
}

.contact-method i {
    font-size: 28px;
    color: var(--primary-color);
    width: 48px;
    height: 48px;
    background: rgba(74, 108, 247, 0.1);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.contact-method h3 {
    font-size: 16px;
    font-weight: 700;
    margin-bottom: 4px;
    color: var(--dark-color);
}

.contact-method p,
.contact-method a {
    color: var(--secondary-color);
    font-size: 14px;
    line-height: 1.5;
    word-break: break-word;
}

.contact-method a:hover {
    color: var(--primary-color);
}

.contact-form-wrapper {
    background: white;
    padding: 40px;
    border-radius: 20px;
    box-shadow: var(--card-shadow);
    border: 1px solid #f1f5f9;
}

.contact-form-wrapper h2 {
    font-size: 28px;
    font-weight: 800;
    margin-bottom: 8px;
    color: var(--dark-color);
}

.contact-form-wrapper > p {
    color: var(--secondary-color);
    margin-bottom: 30px;
    font-size: 15px;
}

.form-group {
    margin-bottom: 22px;
}

.form-group label {
    display: block;
    font-size: 14px;
    font-weight: 600;
    color: var(--dark-color);
    margin-bottom: 8px;
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 14px 16px;
    border: 2px solid #e2e8f0;
    border-radius: 10px;
    font-size: 15px;
    font-family: inherit;
    color: var(--dark-color);
    background: var(--light-color);
    transition: all 0.3s ease;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    background: white;
    box-shadow: 0 0 0 3px rgba(74, 108, 247, 0.1);
}

.form-group textarea {
    resize: vertical;
    min-height: 140px;
}

.submit-btn {
    width: 100%;
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 16px 30px;
    font-size: 16px;
    font-weight: 700;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
}

.submit-btn:hover {
    background: var(--primary-light);
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(74, 108, 247, 0.25);
}

.submit-btn:disabled {
    opacity: 0.7;
    cursor: not-allowed;
    transform: none;
}

.form-success {
    background: rgba(16, 185, 129, 0.1);
    border: 1px solid rgba(16, 185, 129, 0.3);
    color: var(--success-color);
    padding: 16px;
    border-radius: 10px;
    margin-top: 16px;
    font-size: 14px;
    font-weight: 500;
}

.form-error {
    background: rgba(239, 68, 68, 0.1);
    border: 1px solid rgba(239, 68, 68, 0.3);
    color: var(--danger-color);
    padding: 16px;
    border-radius: 10px;
    margin-top: 16px;
    font-size: 14px;
    font-weight: 500;
}

/* 8d. Comparison Table Styles */
.comparison-table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--card-shadow);
    margin: 24px 0;
    font-size: 14px;
}

.comparison-table thead {
    background: var(--primary-color);
    color: white;
}

.comparison-table th,
.comparison-table td {
    padding: 16px 20px;
    text-align: left;
    border-bottom: 1px solid #e2e8f0;
}

.comparison-table th {
    font-weight: 700;
    font-size: 15px;
}

.comparison-table tbody tr:last-child td {
    border-bottom: none;
}

.comparison-table tbody tr:hover {
    background: var(--light-color);
}

/* 9. FAQ Section */
.faq {
    padding: 100px 0;
}

.faq h2 {
    text-align: center;
    font-size: 36px;
    font-weight: 800;
    margin-bottom: 60px;
    color: var(--dark-color);
}

.faq-item {
    background: white;
    border-radius: 16px;
    margin-bottom: 16px;
    box-shadow: var(--card-shadow);
    border: 1px solid #f1f5f9;
    overflow: hidden;
    transition: all 0.3s ease;
}

.faq-item:hover {
    border-color: rgba(74, 108, 247, 0.2);
}

.faq-question {
    padding: 24px 30px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
}

.faq-question h3 {
    font-size: 17px;
    font-weight: 600;
    color: var(--dark-color);
}

.faq-answer {
    padding: 0 30px 24px;
    color: var(--secondary-color);
    font-size: 15px;
    display: none;
    line-height: 1.7;
}

.faq-item.active .faq-answer {
    display: block;
}

.faq-item.active .faq-question {
    color: var(--primary-color);
}

.faq-item.active .fa-chevron-down {
    transform: rotate(180deg);
    color: var(--primary-color);
}

/* 10. Footer */
footer {
    background-color: var(--dark-color);
    color: #f1f5f9;
    padding: 80px 0 30px;
    border-top-left-radius: 40px;
    border-top-right-radius: 40px;
}

.footer-content {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    gap: 40px;
    margin-bottom: 60px;
}

.footer-logo {
    flex: 1.5;
    min-width: 250px;
}

.footer-logo h2 {
    font-size: 28px;
    font-weight: 800;
    margin-bottom: 20px;
    color: white;
}

.footer-logo p {
    color: #94a3b8;
    font-size: 15px;
    max-width: 300px;
}

.footer-links h3, .footer-contact h3 {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 24px;
    color: white;
}

.footer-links ul li {
    margin-bottom: 12px;
}

.footer-links ul li a {
    color: #94a3b8;
    font-size: 14px;
    transition: all 0.3s ease;
}

.footer-links ul li a:hover {
    color: var(--primary-color);
    padding-left: 5px;
}

.footer-contact p {
    color: #94a3b8;
    font-size: 14px;
    margin-bottom: 12px;
}

.footer-contact a {
    color: #94a3b8;
}

.social-icons {
    display: flex;
    gap: 12px;
    margin-top: 24px;
}

.social-icons a {
    width: 36px;
    height: 36px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 10px;
    display: flex;
    justify-content: center;
    align-items: center;
    color: white;
    transition: all 0.3s ease;
}

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

.footer-bottom {
    padding-top: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
    text-align: center;
}

.footer-bottom p {
    color: #64748b;
    font-size: 13px;
}

/* 11. Blog */
.blog-content {
    padding: 60px 0;
    background-color: #f5f7fa;
}

.blog-content h2 {
    text-align: center;
    font-size: 2.5em;
    margin-bottom: 15px;
    color: var(--dark-color);
    font-weight: 700;
}

.blog-content>.container>p {
    text-align: center;
    font-size: 1.2em;
    color: var(--secondary-color);
    margin-bottom: 50px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.blog-posts {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 40px;
    max-width: 1200px;
    margin: 0 auto;
}

.blog-card {
    background: white;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
    position: relative;
}

.blog-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
}

.blog-card a {
    display: block;
    text-decoration: none;
    color: inherit;
    height: 100%;
}

.blog-card img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    transition: transform 0.3s ease;
}

.blog-card:hover img {
    transform: scale(1.05);
}

.blog-card h3 {
    padding: 25px 25px 15px;
    font-size: 1.4em;
    font-weight: 600;
    color: var(--dark-color);
    line-height: 1.4;
    transition: color 0.3s ease;
}

.blog-card:hover h3 {
    color: var(--primary-color);
}

.blog-card p {
    padding: 0 25px 50px;
    color: var(--secondary-color);
    font-size: 1em;
    line-height: 1.6;
    margin-bottom: 0;
}

.blog-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(to right, var(--primary-color), var(--accent-color));
    opacity: 0;
    transition: opacity 0.3s ease;
}

.blog-card:hover::before {
    opacity: 1;
}

.blog-card a::after {
    content: 'Read More →';
    position: absolute;
    bottom: 25px;
    right: 25px;
    color: var(--primary-color);
    font-weight: 500;
    font-size: 0.9em;
    opacity: 0;
    transform: translateX(-10px);
    transition: all 0.3s ease;
}

.blog-card:hover a::after {
    opacity: 1;
    transform: translateX(0);
}

/* 12. Article */
.article-hero {
    margin: 20px 0 30px;
}

.article-hero img {
    display: block;
    width: 100%;
    height: auto;
    border-radius: 12px;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
}

.article-grid {
    display: grid;
    grid-template-columns: 3fr 1fr;
    gap: 30px;
}

.article {
    background-color: white;
    border-radius: 8px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
    padding: 30px;
    margin-bottom: 30px;
}

.article h1 {
    font-size: 32px;
    margin-bottom: 15px;
    color: var(--dark-color);
}

.article-image {
    margin: 20px 0;
    border-radius: 8px;
    overflow: hidden;
}

.article-text {
    line-height: 1.8;
}

.article-text h2 {
    font-size: 24px;
    margin: 30px 0 15px;
    color: var(--dark-color);
}

.article-text h3 {
    font-size: 20px;
    margin: 25px 0 15px;
    color: var(--dark-color);
}

.article-text p,
.article-text ul,
.article-text ol {
    margin-bottom: 20px;
}

.article-text ul,
.article-text ol {
    padding-left: 20px;
}

.article-text li {
    margin-bottom: 10px;
}

.article-tags {
    margin: 30px 0;
}

.article-tags a {
    display: inline-block;
    background-color: #f0f2f5;
    color: var(--secondary-color);
    padding: 5px 10px;
    border-radius: 4px;
    margin-right: 8px;
    margin-bottom: 8px;
    font-size: 14px;
    transition: background-color 0.3s ease, color 0.3s ease;
}

.article-tags a:hover {
    background-color: var(--primary-color);
    color: white;
}

.article-share {
    margin-top: 20px;
    padding-top: 20px;
    border-top: 1px solid #eee;
}

.article-share a {
    display: inline-block;
    width: 36px;
    height: 36px;
    line-height: 36px;
    text-align: center;
    background-color: #f0f2f5;
    color: var(--secondary-color);
    border-radius: 50%;
    margin-right: 10px;
    transition: background-color 0.3s ease, color 0.3s ease;
}

.article-share a:hover {
    background-color: var(--primary-color);
    color: white;
}

.related-articles {
    margin-top: 40px;
}

.related-articles h3 {
    font-size: 24px;
    margin-bottom: 20px;
}

.related-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.related-card {
    background-color: white;
    border-radius: 8px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
    overflow: hidden;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.related-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
}

.related-image {
    height: 150px;
    overflow: hidden;
}

.related-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.related-card h4 {
    padding: 15px;
    font-size: 16px;
    color: var(--dark-color);
}

.about-content,
.privacy-content,
.terms-content {
    padding: 40px 0;
    margin-bottom: 40px;
}

.article-content {
    padding: 60px 0;
    background: linear-gradient(180deg, rgba(246, 248, 250, 0.6) 0%, rgba(255, 255, 255, 0.9) 100%);
}

.article-content .container {
    max-width: 760px;
    margin: 0 auto;
    padding: 0 18px;
}

.article-content h1 {
    font-size: 2.2rem;
    line-height: 1.25;
    letter-spacing: -0.02em;
    margin-bottom: 12px;
    color: var(--dark-color);
}

.article-content .article-meta {
    color: var(--secondary-color);
    font-size: 0.95rem;
    margin-bottom: 18px;
}

.article-content p {
    font-size: 1.05rem;
    line-height: 1.8;
    color: #333;
    margin: 0 0 16px;
}

.article-content .article-lead {
    font-size: 1.15rem;
    line-height: 1.85;
    color: #2c2c2c;
    margin-bottom: 18px;
}

.article-content h2 {
    font-size: 1.6rem;
    margin: 30px 0 12px;
    color: #222;
}

.article-content h3 {
    font-size: 1.25rem;
    margin: 22px 0 8px;
    color: #222;
}

.article-content ul,
.article-content ol {
    padding-left: 22px;
    margin: 8px 0 18px;
}

.article-content li {
    margin-bottom: 8px;
}

.article-tldr {
    background: #f0f7ff;
    border: 1px solid #d6e6ff;
    border-left: 4px solid #2f7fff;
    border-radius: 8px;
    padding: 16px 16px 12px;
    margin: 18px 0 24px;
}

.article-tldr>strong {
    display: inline-block;
    margin-bottom: 8px;
    color: #1f5fd6;
}

.callout {
    padding: 14px 16px;
    border-radius: 8px;
    margin: 18px 0;
    border: 1px solid rgba(0, 0, 0, 0.08);
    background: #fafafa;
}

.callout strong {
    display: block;
    margin-bottom: 6px;
}

.callout.tip {
    border-left: 4px solid #2f9e44;
    background: #f2fbf5;
}

.callout.info {
    border-left: 4px solid #1c7ed6;
    background: #eef6ff;
}

.callout.warn {
    border-left: 4px solid #f59f00;
    background: #fff7e6;
}

.callout.danger {
    border-left: 4px solid #e03131;
    background: #fff1f1;
}

.article-content blockquote {
    border-left: 4px solid #e5e7eb;
    padding: 8px 16px;
    margin: 16px 0;
    color: #555;
    background: #fbfbfc;
    border-radius: 6px;
    font-style: italic;
}

.article-content code {
    background: #f6f8fa;
    border: 1px solid #e1e4e8;
    border-radius: 4px;
    padding: 2px 6px;
    font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
    font-size: 0.95rem;
}

.article-content pre {
    background: #f6f8fa;
    border: 1px solid #e1e4e8;
    border-radius: 8px;
    padding: 14px;
    overflow: auto;
    margin: 16px 0 18px;
}

.article-content table {
    width: 100%;
    border-collapse: collapse;
    margin: 12px 0 18px;
    font-size: 0.98rem;
}

.article-content th,
.article-content td {
    border: 1px solid #e5e7eb;
    padding: 10px 12px;
    text-align: left;
}

.article-content thead th {
    background: #f4f6f8;
}

.article-content tbody tr:nth-child(odd) {
    background: #fcfcfd;
}

.article-content figure {
    margin: 18px 0;
    text-align: center;
}

.article-content figcaption {
    font-size: 0.9rem;
    color: #666;
    margin-top: 6px;
}

.article-layout {
    display: grid;
    grid-template-columns: 1fr;
    gap: 24px;
}

.article-main>*:first-child {
    margin-top: 0;
}

.article-sidebar {
    display: block;
}

.sidebar-widget {
    background: #fff;
    border: 1px solid #e9ecef;
    border-radius: 12px;
    padding: 16px;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.04);
}

.sidebar-widget+.sidebar-widget {
    margin-top: 18px;
}

.sidebar-widget h3 {
    font-size: 1.05rem;
    font-weight: 700;
    margin: 2px 0 12px;
    color: var(--dark-color);
}

.popular-articles {
    display: grid;
    gap: 8px;
    padding: 0;
    margin: 0;
    counter-reset: rank;
}

.popular-articles li {
    counter-increment: rank;
}

.popular-articles li a {
    display: grid;
    grid-template-columns: 28px 44px 1fr;
    /* rank badge, thumbnail, title */
    align-items: center;
    gap: 10px;
    padding: 10px 10px;
    border-radius: 10px;
    color: var(--dark-color);
    background: linear-gradient(180deg, #ffffff 0%, #fafbfc 100%);
    border: 1px solid #eef1f4;
    transition: background 0.25s ease, transform 0.2s ease, box-shadow 0.25s ease, border-color 0.25s ease;
}

.popular-articles li a::before {
    content: counter(rank);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 28px;
    height: 28px;
    border-radius: 8px;
    background: #eef4ff;
    color: #2f5be6;
    /* accent */
    font-weight: 700;
    font-size: 0.95rem;
    line-height: 1;
    border: 1px solid #dce6ff;
}

.popular-articles li a:hover {
    background: #f6faff;
    transform: translateY(-1px);
    box-shadow: 0 6px 18px rgba(47, 91, 230, 0.08);
    border-color: #d7e3ff;
}

.popular-articles li a:active {
    transform: translateY(0);
    box-shadow: 0 2px 10px rgba(47, 91, 230, 0.06);
}

.popular-articles li a:focus-visible {
    outline: 2px solid #2f5be6;
    outline-offset: 2px;
}

.popular-thumb {
    width: 44px;
    height: 44px;
    border-radius: 10px;
    object-fit: cover;
    background: #f3f5f7;
    border: 1px solid #e8ebf0;
}

.article-sidebar .popular-posts {
    background: #fff;
    border: 1px solid #e9ecef;
    border-radius: 12px;
    padding: 16px;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.04);
}

.article-sidebar .popular-posts h3 {
    font-size: 1.05rem;
    font-weight: 700;
    margin: 2px 0 12px;
    color: var(--dark-color);
}

.article-sidebar .popular-posts ul {
    display: grid;
    gap: 8px;
    padding: 0;
    margin: 0;
    counter-reset: rank;
}

.article-sidebar .popular-posts li {
    counter-increment: rank;
}

.article-sidebar .popular-posts li a {
    display: grid;
    grid-template-columns: 28px 44px 1fr;
    /* rank badge, thumbnail, title */
    align-items: center;
    gap: 10px;
    padding: 10px 10px;
    border-radius: 10px;
    color: var(--dark-color);
    background: linear-gradient(180deg, #ffffff 0%, #fafbfc 100%);
    border: 1px solid #eef1f4;
    transition: background 0.25s ease, transform 0.2s ease, box-shadow 0.25s ease, border-color 0.25s ease;
}

.article-sidebar .popular-posts li a::before {
    content: counter(rank);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 28px;
    height: 28px;
    border-radius: 8px;
    background: #eef4ff;
    color: #2f5be6;
    font-weight: 700;
    font-size: 0.95rem;
    line-height: 1;
    border: 1px solid #dce6ff;
}

.article-sidebar .popular-posts li a:hover {
    background: #f6faff;
    transform: translateY(-1px);
    box-shadow: 0 6px 18px rgba(47, 91, 230, 0.08);
    border-color: #d7e3ff;
}

.article-sidebar .popular-posts li a:active {
    transform: translateY(0);
    box-shadow: 0 2px 10px rgba(47, 91, 230, 0.06);
}

.article-sidebar .popular-posts li a:focus-visible {
    outline: 2px solid #2f5be6;
    outline-offset: 2px;
}

.article-main .further-reading {
    list-style: none;
    margin: 16px 0 0;
    padding: 0;
    border: 1px solid #e6e8eb;
    border-radius: 12px;
    background: #fff;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.04);
    overflow: hidden;
}

.article-main .further-reading li {
    border-top: 1px solid #eef0f2;
}

.article-main .further-reading li:first-child {
    border-top: none;
}

.article-main .further-reading a {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    color: #1f2937;
    /* slate-800 */
    text-decoration: none;
    transition: background 0.18s ease, color 0.18s ease;
}

.article-main .further-reading a::before {
    content: "";
    /* link icon */
    font-family: "Font Awesome 6 Free";
    font-weight: 900;
    font-size: 0.95rem;
    color: #64748b;
    /* slate-500 */
}

.article-main .further-reading a:hover {
    background: #f8fafc;
    /* slate-50 */
    color: #0f172a;
    /* slate-900 */
}

.article-main .further-reading a:active {
    background: #f1f5f9;
}

.article-main .further-reading a:focus-visible {
    outline: 2px solid #3b82f6;
    /* blue-500 */
    outline-offset: 2px;
}

.article-main h2+.further-reading {
    margin-top: 8px;
}

/* 13. Ads */
.ad-container {
    background-color: var(--ad-background);
    border: 1px solid var(--ad-border);
    border-radius: 8px;
    padding: 15px;
    margin: 30px auto;
    text-align: center;
    color: var(--secondary-color);
    font-size: 14px;
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;
}

.header-ad-container {
    margin: 20px 0;
    min-height: 90px;
}

.header-ad-unit {
    width: 728px;
    height: 90px;
    background-color: #e9ecef;
    display: flex;
    justify-content: center;
    align-items: center;
    font-weight: bold;
    color: #6c757d;
    border: 1px dashed #adb5bd;
}

.widget-ad-long {
    min-height: 250px;
    width: 300px;
    background-color: #e9ecef;
    display: flex;
    justify-content: center;
    align-items: center;
    font-weight: bold;
    color: #6c757d;
    border: 1px dashed #adb5bd;
    margin-bottom: 20px;
}

.widget-ad-300x300 {
    min-height: 250px;
    width: 300px;
    background-color: #e9ecef;
    display: flex;
    justify-content: center;
    align-items: center;
    font-weight: bold;
    color: #6c757d;
    border: 1px dashed #adb5bd;
}

.ad-in-content {
    margin: 40px auto;
    max-width: 728px;
    min-height: 90px;
    background-color: #e9ecef;
    display: flex;
    justify-content: center;
    align-items: center;
    font-weight: bold;
    color: #6c757d;
    border: 1px dashed #adb5bd;
}

/* 14. Dark Mode */
@media (prefers-color-scheme: dark) {
    body {
        background-color: #1a202c;
        color: #e2e8f0;
    }

    header {
        background-color: #2d3748;
        box-shadow: 0 4px 20px rgba(0, 0, 0, 0.4);
    }

    nav ul li a {
        color: #e2e8f0;
    }

    nav ul li a:hover {
        background-color: rgba(74, 108, 247, 0.15);
        color: #fff;
    }

    nav ul li a.active {
        background-color: var(--primary-color);
        color: white;
    }

    .hero {
        background-color: #2d3748;
    }

    .hero h2,
    .features h2,
    .popular-conversions h2,
    .how-it-works h2,
    .testimonials h2,
    .faq h2,
    .blog-content h2,
    .article h1,
    .article-text h2,
    .article-text h3,
    .related-articles h3,
    .sidebar-widget h3,
    .article-sidebar .popular-posts h3 {
        color: #e2e8f0;
    }

    .converter-box,
    .feature-card,
    .conversion-card,
    .testimonial,
    .faq-item,
    .blog-card,
    .article,
    .sidebar-widget,
    .article-sidebar .popular-posts {
        background-color: #2d3748;
        box-shadow: 0 5px 15px rgba(0, 0, 0, 0.5);
    }

    .upload-area {
        border-color: #4a5568;
    }

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

    .format-selection select {
        background-color: #4a5568;
        color: #e2e8f0;
        border-color: #4a5568;
    }

    .article-main .further-reading {
        background: #0b1020;
        border-color: #192040;
        box-shadow: none;
    }

    .article-main .further-reading li {
        border-top-color: #192040;
    }

    .article-main .further-reading a {
        color: #e5e7eb;
    }

    .article-main .further-reading a::before {
        color: #94a3b8;
    }

    .article-main .further-reading a:hover {
        background: #0f172a;
        color: #ffffff;
    }
}

/* 15. Responsive Styles */
@media (min-width: 992px) {
    .article-content .container {
        max-width: 1080px;
    }

    .article-layout {
        grid-template-columns: minmax(0, 1fr) 320px;
        align-items: start;
        gap: 28px;
    }

    .article-sidebar {
        position: sticky;
        top: 88px;
        /* below header */
        height: fit-content;
    }
}

@media (max-width: 768px) {
    nav {
        display: none;
    }

    .mobile-menu-toggle {
        display: block;
    }

    .hero h2 {
        font-size: 28px;
        text-align: center;
    }

    .hero p {
        font-size: 16px;
        text-align: center;
    }

    .format-selection {
        flex-direction: column;
    }

    .from-format,
    .to-format {
        width: 100%;
        margin-bottom: 15px;
    }

    .steps {
        flex-direction: column;
    }

    .step {
        margin-bottom: 30px;
    }

    .footer-content {
        flex-direction: column;
    }

    .blog-content h2 {
        font-size: 2em;
    }

    .blog-content>.container>p {
        font-size: 1.1em;
        padding: 0 20px;
    }

    .blog-posts {
        grid-template-columns: 1fr;
        gap: 30px;
        padding: 0 20px;
    }

    .blog-card {
        margin: 0 auto;
        max-width: 400px;
    }

    .blog-card h3 {
        font-size: 1.2em;
        padding: 20px 20px 10px;
    }

    .blog-card p {
        padding: 0 20px 45px;
        font-size: 0.95em;
    }

    .blog-card a::after {
        bottom: 20px;
        right: 20px;
        font-size: 0.85em;
    }

    .header-ad-unit {
        width: 320px;
        height: 50px;
    }

    .widget-ad-long,
    .widget-ad-300x300 {
        width: 100%;
        max-width: 300px;
        margin-left: auto;
        margin-right: auto;
    }

    .ad-in-content {
        max-width: 320px;
        height: 50px;
    }

    .article-content {
        padding: 40px 0;
    }

    .article-content .container {
        max-width: 680px;
    }

    .article-content h1 {
        font-size: 2rem;
    }

    .article-content h2 {
        font-size: 1.45rem;
    }

    .article-content h3 {
        font-size: 1.15rem;
    }

    .article-content p {
        font-size: 1rem;
    }

    .article-content .article-lead {
        font-size: 1.08rem;
    }

    .article-sidebar .popular-posts li a {
        grid-template-columns: 24px 40px 1fr;
        gap: 8px;
        padding: 8px 9px;
    }

    .popular-thumb {
        width: 40px;
        height: 40px;
    }
}

@media (max-width: 640px) {
    .article-main .further-reading a {
        padding: 10px 14px;
        gap: 10px;
    }
}

@media (max-width: 480px) {
    .blog-content {
        padding: 40px 0;
    }

    .blog-content h2 {
        font-size: 1.8em;
    }

    .blog-card img {
        height: 180px;
    }

    .blog-card h3 {
        font-size: 1.1em;
    }

    .article-content .container {
        padding: 0 14px;
    }

    .article-content h1 {
        font-size: 1.8rem;
    }

    .article-content h2 {
        font-size: 1.3rem;
    }

    .article-content h3 {
        font-size: 1.08rem;
    }
}