/* Reset и базовые стили */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #6366f1;
    --primary-hover: #5856eb;
    --secondary-color: #f8fafc;
    --accent-color: #10b981;
    --danger-color: #ef4444;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
    --radius: 12px;
    --radius-lg: 16px;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

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

/* Header */
.header {
    text-align: center;
    padding: 60px 0 40px;
    color: white;
}

.header-content h1 {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 700;
    margin-bottom: 16px;
    text-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}

.logo i {
    margin-right: 16px;
    color: #fbbf24;
}

.tagline {
    font-size: clamp(1.1rem, 2.5vw, 1.4rem);
    opacity: 0.9;
    font-weight: 300;
}

/* Main Content */
.main-content {
    background: white;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
    margin-bottom: 60px;
    overflow: hidden;
}

/* Upload Section */
.upload-section {
    padding: 60px 40px;
    text-align: center;
}

.upload-area {
    border: 2px dashed var(--border-color);
    border-radius: var(--radius);
    padding: 60px 40px;
    transition: all 0.3s ease;
    cursor: pointer;
    position: relative;
    background: var(--secondary-color);
}

.upload-area:hover,
.upload-area.dragover {
    border-color: var(--primary-color);
    background: #f0f9ff;
    transform: translateY(-2px);
}

.upload-content {
    max-width: 400px;
    margin: 0 auto;
}

.upload-icon {
    font-size: 4rem;
    color: var(--primary-color);
    margin-bottom: 24px;
}

.upload-area h2 {
    font-size: 1.8rem;
    margin-bottom: 12px;
    font-weight: 600;
}

.upload-area p {
    color: var(--text-secondary);
    margin-bottom: 32px;
    font-size: 1.1rem;
}

.file-input {
    display: none;
}

.upload-btn {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 16px 32px;
    border-radius: var(--radius);
    font-size: 1.1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: var(--shadow-md);
}

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

/* File Info Section */
.file-info-section {
    padding: 0 40px 40px;
}

.file-info-card {
    background: var(--secondary-color);
    border-radius: var(--radius);
    padding: 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    border: 1px solid var(--border-color);
}

.file-preview {
    display: flex;
    align-items: center;
    gap: 16px;
}

.file-icon {
    font-size: 2.5rem;
    color: var(--primary-color);
}

.file-details h3 {
    font-size: 1.2rem;
    margin-bottom: 4px;
}

.file-details p {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.remove-file-btn {
    background: var(--danger-color);
    color: white;
    border: none;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.remove-file-btn:hover {
    background: #dc2626;
    transform: scale(1.1);
}

/* Conversion Section */
.conversion-section {
    padding: 0 40px 40px;
}

.conversion-section h3 {
    font-size: 1.4rem;
    margin-bottom: 24px;
    text-align: center;
}

.format-options {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: 16px;
    margin-bottom: 32px;
}

.format-option {
    background: white;
    border: 2px solid var(--border-color);
    border-radius: var(--radius);
    padding: 20px 16px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
}

.format-option:hover {
    border-color: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.format-option.selected {
    border-color: var(--primary-color);
    background: #f0f9ff;
}

.format-option.selected::after {
    content: '✓';
    position: absolute;
    top: 8px;
    right: 8px;
    background: var(--primary-color);
    color: white;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
}

.format-icon {
    font-size: 2rem;
    margin-bottom: 8px;
    color: var(--primary-color);
}

.format-name {
    font-weight: 600;
    font-size: 0.9rem;
    text-transform: uppercase;
}

/* Quality Settings */
.quality-settings {
    background: var(--secondary-color);
    padding: 24px;
    border-radius: var(--radius);
    margin-bottom: 32px;
}

.quality-settings h4 {
    margin-bottom: 16px;
    color: var(--text-primary);
}

.quality-option {
    display: flex;
    align-items: center;
    gap: 16px;
}

.quality-option label {
    font-weight: 500;
    min-width: 80px;
}

.slider {
    flex: 1;
    height: 6px;
    border-radius: 3px;
    background: var(--border-color);
    outline: none;
    -webkit-appearance: none;
}

.slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary-color);
    cursor: pointer;
}

.slider::-moz-range-thumb {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary-color);
    cursor: pointer;
    border: none;
}

#qualityValue {
    font-weight: 600;
    color: var(--primary-color);
    min-width: 50px;
}

.convert-btn {
    width: 100%;
    background: var(--accent-color);
    color: white;
    border: none;
    padding: 20px;
    border-radius: var(--radius);
    font-size: 1.2rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: var(--shadow-md);
}

.convert-btn:hover {
    background: #059669;
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.convert-btn i {
    margin-right: 12px;
}

/* Progress Section */
.progress-section {
    padding: 40px;
    text-align: center;
}

.progress-card h3 {
    margin-bottom: 24px;
    font-size: 1.4rem;
}

.progress-bar {
    background: var(--border-color);
    height: 12px;
    border-radius: 6px;
    overflow: hidden;
    margin-bottom: 16px;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
    width: 0%;
    transition: width 0.5s ease;
    border-radius: 6px;
}

.progress-text {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--primary-color);
}

/* Download Section */
.download-section {
    padding: 40px;
    text-align: center;
}

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

.success-icon {
    font-size: 4rem;
    color: var(--accent-color);
    margin-bottom: 24px;
}

.download-card h3 {
    font-size: 1.6rem;
    margin-bottom: 12px;
    color: var(--accent-color);
}

.download-card p {
    color: var(--text-secondary);
    margin-bottom: 32px;
    font-size: 1.1rem;
}

.download-btn {
    background: var(--accent-color);
    color: white;
    border: none;
    padding: 16px 32px;
    border-radius: var(--radius);
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: var(--shadow-md);
    margin-bottom: 16px;
    display: inline-block;
    text-decoration: none;
}

.download-btn:hover {
    background: #059669;
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.download-btn i {
    margin-right: 12px;
}

.new-conversion-btn {
    background: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
    padding: 12px 24px;
    border-radius: var(--radius);
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-left: 16px;
}

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

/* Features Section */
.features-section {
    background: white;
    border-radius: var(--radius-lg);
    padding: 60px 40px;
    margin-bottom: 60px;
    box-shadow: var(--shadow-xl);
}

.features-section h2 {
    text-align: center;
    font-size: 2.2rem;
    margin-bottom: 48px;
    font-weight: 700;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 32px;
}

.feature-card {
    text-align: center;
    padding: 32px 24px;
    border-radius: var(--radius);
    background: var(--secondary-color);
    transition: all 0.3s ease;
}

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

.feature-card i {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 20px;
}

.feature-card h3 {
    font-size: 1.3rem;
    margin-bottom: 12px;
    font-weight: 600;
}

.feature-card p {
    color: var(--text-secondary);
    line-height: 1.7;
}

/* Footer */
.footer {
    text-align: center;
    padding: 40px 0;
    color: rgba(255, 255, 255, 0.8);
}

/* Utility Classes */
.hidden {
    display: none !important;
}

/* Mobile Responsiveness */
@media (max-width: 768px) {
    .container {
        padding: 0 16px;
    }
    
    .header {
        padding: 40px 0 30px;
    }
    
    .upload-section {
        padding: 40px 20px;
    }
    
    .upload-area {
        padding: 40px 20px;
    }
    
    .file-info-section,
    .conversion-section,
    .progress-section,
    .download-section {
        padding: 20px;
    }
    
    .file-info-card {
        flex-direction: column;
        gap: 16px;
        text-align: center;
    }
    
    .format-options {
        grid-template-columns: repeat(auto-fit, minmax(100px, 1fr));
        gap: 12px;
    }
    
    .quality-option {
        flex-direction: column;
        gap: 12px;
        align-items: stretch;
    }
    
    .features-section {
        padding: 40px 20px;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
        gap: 24px;
    }
    
    .new-conversion-btn {
        margin-left: 0;
        margin-top: 16px;
        display: block;
        width: 100%;
    }
}

@media (max-width: 480px) {
    .format-options {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .upload-area {
        padding: 30px 16px;
    }
    
    .upload-content {
        max-width: 100%;
    }
    
    .upload-icon {
        font-size: 3rem;
    }
}

/* Анимации */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in {
    animation: fadeIn 0.5s ease-out;
}

@keyframes pulse {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
}

.pulse {
    animation: pulse 2s infinite;
}

/* Дополнительные стили для иконок файлов */
.file-icon.fa-file-image { color: #f59e0b; }
.file-icon.fa-file-video { color: #ef4444; }
.file-icon.fa-file-audio { color: #8b5cf6; }
.file-icon.fa-file-pdf { color: #dc2626; }
.file-icon.fa-file-word { color: #2563eb; }
.file-icon.fa-file-excel { color: #059669; }
.file-icon.fa-file-powerpoint { color: #ea580c; }
.file-icon.fa-file-archive { color: #6b7280; }
.file-icon.fa-file-code { color: #10b981; }
.file-icon.fa-file { color: var(--text-secondary); }

/* Публичная статистика */
.public-stats {
    text-align: center;
    margin-top: 10px;
    opacity: 0.6;
}

.stats-info {
    font-size: 12px;
    color: #64748b;
}

/* About, How It Works, Advantages, Formats, Technical, Guide Sections */
.about-section,
.how-it-works-section,
.advantages-section,
.formats-section,
.technical-section,
.guide-section {
    background: white;
    margin: 40px 0;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    overflow: hidden;
}

.about-content,
.how-content,
.advantages-content,
.formats-content,
.technical-content,
.guide-content {
    padding: 60px 40px;
    max-width: 900px;
    margin: 0 auto;
}

.about-section h2,
.how-it-works-section h2,
.advantages-section h2,
.formats-section h2,
.technical-section h2,
.guide-section h2 {
    font-size: 2.2rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 32px;
    text-align: center;
    position: relative;
}

.about-section h2::after,
.how-it-works-section h2::after,
.advantages-section h2::after,
.formats-section h2::after,
.technical-section h2::after,
.guide-section h2::after {
    content: '';
    position: absolute;
    bottom: -12px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
    border-radius: 2px;
}

.about-content p,
.how-content p,
.advantages-content p,
.formats-content p,
.technical-content p,
.guide-content p {
    font-size: 1.1rem;
    line-height: 1.8;
    color: var(--text-primary);
    margin-bottom: 24px;
    text-align: justify;
}

.about-content p:last-child,
.how-content p:last-child,
.advantages-content p:last-child,
.formats-content p:last-child,
.technical-content p:last-child,
.guide-content p:last-child {
    margin-bottom: 0;
}

/* Mobile Styles for New Sections */
@media (max-width: 768px) {
    .about-content,
    .how-content,
    .advantages-content,
    .formats-content,
    .technical-content,
    .guide-content {
        padding: 40px 24px;
    }
    
    .about-section h2,
    .how-it-works-section h2,
    .advantages-section h2,
    .formats-section h2,
    .technical-section h2,
    .guide-section h2 {
        font-size: 1.8rem;
        margin-bottom: 24px;
    }
    
    .about-content p,
    .how-content p,
    .advantages-content p,
    .formats-content p,
    .technical-content p,
    .guide-content p {
        font-size: 1rem;
        line-height: 1.7;
        text-align: left;
    }
}