:root {
    --bg-color: #ffffff;
    --text-color: #333333;
    --card-bg: #f8f9fa;
    --border-color: #e9ebf3;
    --accent-color: #243f8f;
    --accent-hover: #1a2f6d;
    --shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    --progress-bg: #e9ecef;
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg-color: #1a1a1a;
        --text-color: #e0e0e0;
        --card-bg: #2d2d2d;
        --border-color: #404040;
        --accent-color: #3a5bb8;
        --accent-hover: #4a6bc8;
        --shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
        --progress-bg: #404040;
    }
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: var(--bg-color);
    color: var(--text-color);
    min-height: 100vh;
    padding: 20px;
    line-height: 1.6;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    background: var(--bg-color);
    border-radius: 8px;
    padding: 30px;
    border: 1px solid var(--border-color);
}

h1, h2, h3 {
    color: var(--text-color);
    margin-bottom: 20px;
    font-weight: 600;
    line-height: 1.3;
}

h1 {
    font-size: 2.5rem;
}

h2 {
    font-size: 2rem;
}

h3 {
    font-size: 1.5rem;
}

h4 {
    font-size: 1.1rem;
}

p {
    margin-bottom: 20px;
}

.card {
    background: var(--card-bg);
    padding: 30px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    margin: 20px 0;
}

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

label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: var(--text-color);
    font-size: 1rem;
}

input[type="file"] {
    width: 100%;
    padding: 16px;
    border: 2px dashed var(--border-color);
    border-radius: 8px;
    background: var(--bg-color);
    color: var(--text-color);
    font-size: 1rem;
    cursor: pointer;
    transition: border-color 0.3s ease;
}

input[type="file"]:hover {
    border-color: var(--accent-color);
}

input[type="file"]:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(36, 63, 143, 0.1);
}

.btn {
    background: var(--accent-color);
    color: white;
    padding: 8px 16px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 600;
    transition: all 0.3s ease;
    display: inline-block;
    text-align: center;
    text-decoration: none;
}

.btn:hover {
    background: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(36, 63, 143, 0.2);
}

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

.progress-bar {
    width: 100%;
    height: 24px;
    background: var(--progress-bg);
    border-radius: 8px;
    overflow: hidden;
    margin: 20px 0;
    border: 1px solid var(--border-color);
}

.progress {
    height: 100%;
    background: linear-gradient(90deg, var(--accent-color), var(--accent-hover));
    border-radius: 8px;
    transition: width 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.progress::after {
    content: attr(data-progress);
    color: white;
    font-weight: 600;
    font-size: 0.9rem;
    text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.3);
}

.api-example {
    background: var(--bg-color);
    padding: 20px;
    border-radius: 8px;
    border-left: 4px solid var(--accent-color);
    margin: 20px 0;
    border: 1px solid var(--border-color);
}

code {
    background: rgba(36, 63, 143, 0.1);
    padding: 4px 8px;
    border-radius: 6px;
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
    font-size: 0.9rem;
    color: var(--accent-color);
    border: 1px solid var(--border-color);
}

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

a:hover {
    color: var(--accent-hover);
    text-decoration: underline;
}

#progressText {
    text-align: center;
    font-weight: 600;
    color: var(--text-color);
    margin: 10px 0;
}

#downloadLink {
    font-weight: 600;
    font-size: 1rem;
}

/* Адаптивность */
@media (max-width: 768px) {
    .container {
        padding: 20px;
        margin: 10px;
    }
    
    .card {
        padding: 20px;
    }
    
    h1 {
        font-size: 2rem;
        margin-bottom: 15px;
    }
    
    h2 {
        font-size: 1.5rem;
        margin-bottom: 15px;
    }
    
    h3 {
        font-size: 1.25rem;
        margin-bottom: 15px;
    }
    
    .btn {
        padding: 14px 24px;
        font-size: 1rem;
        width: 100%;
    }
    
    input[type="file"] {
        padding: 12px;
    }
}

@media (max-width: 480px) {
    body {
        padding: 10px;
    }
    
    .container {
        padding: 15px;
    }
    
    .card {
        padding: 15px;
    }
    
    h1 {
        font-size: 1.75rem;
    }
}

/* Улучшения для темной темы в медиа-запросе */
@media (prefers-color-scheme: dark) {
    code {
        background: rgba(58, 91, 184, 0.15);
        color: #8ba1ff;
    }
    
    #result {
        background: rgba(58, 91, 184, 0.08);
    }
    
    input[type="file"] {
        background: #2d2d2d;
    }
}

/* Анимации */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

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

.card {
    animation: fadeIn 0.6s ease-out;
}

/* Состояния загрузки */
.btn:disabled {
    background: #6c757d;
    cursor: not-allowed;
    transform: none;
}

.btn:disabled:hover {
    background: #6c757d;
    transform: none;
    box-shadow: none;
}