:root {
    --primary-color: #4a6bff;
    --secondary-color: #6c757d;
    --success-color: #28a745;
    --danger-color: #dc3545;
    --warning-color: #fd7e14;
    --info-color: #17a2b8;
    --light-color: #f8f9fa;
    --dark-color: #343a40;
    --white: #ffffff;
    --gray-light: #e9ecef;
    --gray: #adb5bd;
    --gray-dark: #495057;
    --body-bg: #f5f7ff;
    --card-bg: #ffffff;
    --text-color: #212529;
    --text-muted: #6c757d;
    --border-color: #dee2e6;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 8px 15px rgba(0, 0, 0, 0.1);
    --border-radius: 8px;
    --transition: all 0.3s ease;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--body-bg);
    padding-top: 60px;
}

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

a:hover {
    color: #3a56d4;
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header Styles */
header {
    background-color: var(--white);
    box-shadow: var(--shadow);
    position: fixed;
    width: 100%;
    top: 0;
    left: 0;
    z-index: 1000;
}

.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 0;
}

.logo {
    font-size: 24px;
    font-weight: 700;
    color: var(--primary-color);
    display: flex;
    align-items: center;
}

.logo img {
    height: 40px;
    margin-right: 10px;
}

.nav-links {
    display: flex;
    list-style: none;
}

.nav-links li {
    margin-left: 25px;
}

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

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

/* Hero Section */
.hero-section {
    text-align: center;
    padding: 60px 0 40px;
}

.hero-section h1 {
    font-size: 2.5rem;
    margin-bottom: 15px;
    color: var(--dark-color);
}

.subtitle {
    font-size: 1.2rem;
    color: var(--text-muted);
    margin-bottom: 40px;
}

/* Converter Box */
.converter-box {
    background-color: var(--white);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    padding: 30px;
    margin-bottom: 40px;
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
}

.dropzone {
    flex: 1;
    min-width: 300px;
    border: 2px dashed var(--border-color);
    border-radius: var(--border-radius);
    padding: 40px 20px;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    margin-right: 20px;
    margin-bottom: 20px;
}

.dropzone:hover {
    border-color: var(--primary-color);
    background-color: rgba(74, 107, 255, 0.05);
}

.dropzone i {
    font-size: 48px;
    color: var(--primary-color);
    margin-bottom: 15px;
}

.dropzone h3 {
    margin-bottom: 10px;
}

.dropzone p {
    margin: 10px 0;
    color: var(--text-muted);
}

.options-box {
    flex: 0 0 300px;
    padding: 20px;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
}

.form-control {
    width: 100%;
    padding: 10px 15px;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 16px;
    transition: var(--transition);
}

.form-control:focus {
    border-color: var(--primary-color);
    outline: none;
    box-shadow: 0 0 0 3px rgba(74, 107, 255, 0.25);
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 10px 20px;
    border-radius: var(--border-radius);
    font-weight: 500;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    border: none;
}

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

.btn-primary:hover {
    background-color: #3a56d4;
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
}

.btn-convert {
    background-color: var(--success-color);
    color: var(--white);
    width: 100%;
    padding: 12px;
    font-size: 16px;
}

.btn-convert:hover {
    background-color: #218838;
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
}

.btn-convert:disabled {
    background-color: var(--gray);
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

.btn-download {
    background-color: var(--info-color);
    color: var(--white);
    margin-top: 10px;
    width: 100%;
}

.btn-download:hover {
    background-color: #138496;
}

/* Features Section */
.features-section {
    padding: 60px 0;
    text-align: center;
}

.features-section h2 {
    margin-bottom: 40px;
    font-size: 2rem;
}

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

.feature-card {
    background-color: var(--white);
    border-radius: var(--border-radius);
    padding: 30px 20px;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

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

.feature-card i {
    font-size: 40px;
    color: var(--primary-color);
    margin-bottom: 20px;
}

.feature-card h3 {
    margin-bottom: 15px;
    font-size: 1.3rem;
}

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

/* Conversion Results */
.conversion-results {
    padding: 60px 0;
}

.preview-gallery {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 20px;
    margin: 30px 0;
}

.preview-item {
    background-color: var(--white);
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

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

.preview-item img {
    width: 100%;
    height: auto;
    display: block;
    border-bottom: 1px solid var(--border-color);
}

.file-info {
    padding: 15px;
    font-size: 14px;
    color: var(--text-muted);
}

.download-all {
    text-align: center;
    margin-top: 30px;
}

/* Footer */
footer {
    background-color: var(--dark-color);
    color: var(--white);
    padding: 40px 0 20px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 30px;
    margin-bottom: 30px;
}

.footer-column h3 {
    color: var(--white);
    margin-bottom: 20px;
    font-size: 1.2rem;
}

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

.footer-links li {
    margin-bottom: 10px;
}

.footer-links a {
    color: var(--gray);
    transition: var(--transition);
}

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

.copyright {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: var(--gray);
    font-size: 14px;
}

/* Ad Space */
.ad-space {
    margin: 40px 0;
    padding: 20px;
    background-color: var(--gray-light);
    border-radius: var(--border-radius);
    text-align: center;
}

/* Responsive */
@media (max-width: 768px) {
    .converter-box {
        flex-direction: column;
    }
    
    .dropzone {
        margin-right: 0;
        margin-bottom: 30px;
    }
    
    .options-box {
        flex: 1;
    }
    
    .navbar {
        flex-direction: column;
    }
    
    .nav-links {
        margin-top: 20px;
    }
    
    .nav-links li {
        margin: 0 10px;
    }
}