:root {
    /* Светлая тема */
    --bg-primary: #F7FAFC;
    --bg-secondary: #FFFFFF;
    --text-primary: #1A202C;
    --text-secondary: #4A5568;
    --accent: #3182CE;
    --accent-hover: #2C5AA0;
    --border: #E2E8F0;
    --dropzone-bg: #EDF2F7;
    --dropzone-border: #CBD5E0;
    --dropzone-active: #BEE3F8;
    --success: #48BB78;
    --error: #F56565;
    --warning: #ED8936;
}

[data-theme="dark"] {
    /* Тёмная тема */
    --bg-primary: #111827;
    --bg-secondary: #1F2937;
    --text-primary: #F9FAFB;
    --text-secondary: #D1D5DB;
    --accent: #60A5FA;
    --accent-hover: #3B82F6;
    --border: #374151;
    --dropzone-bg: #1F2937;
    --dropzone-border: #4B5563;
    --dropzone-active: #3B82F6;
    --success: #34D399;
    --error: #F87171;
    --warning: #FBBF24;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    min-height: 100vh;
    transition: background-color 0.3s ease, color 0.3s ease;
}

.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 20px;
}

header {
    background-color: var(--bg-secondary);
    padding: 15px 0;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 100;
    transition: background-color 0.3s ease;
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
}

.logo {
    font-size: 24px;
    font-weight: bold;
    color: var(--accent);
}

.theme-selector {
    display: flex;
    align-items: center;
    gap: 10px;
}

.theme-selector select {
    padding: 8px 12px;
    border: 1px solid var(--border);
    border-radius: 6px;
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    font-size: 14px;
    cursor: pointer;
    transition: border-color 0.3s ease;
}

.theme-selector select:hover {
    border-color: var(--accent);
}

main {
    padding: 40px 0;
}

h1 {
    font-size: 36px;
    margin-bottom: 15px;
    text-align: center;
    color: var(--text-primary);
}

.subtitle {
    text-align: center;
    color: var(--text-secondary);
    margin-bottom: 40px;
    font-size: 16px;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

.dropzone {
    border: 3px dashed var(--dropzone-border);
    border-radius: 12px;
    padding: 60px 20px;
    text-align: center;
    background-color: var(--dropzone-bg);
    cursor: pointer;
    transition: all 0.3s ease;
    margin-bottom: 20px;
}

.dropzone:hover,
.dropzone.dragover {
    border-color: var(--accent);
    background-color: var(--dropzone-active);
}

.dropzone-text {
    font-size: 18px;
    color: var(--text-secondary);
    margin-bottom: 20px;
}

.file-input-wrapper {
    position: relative;
    display: inline-block;
}

.file-input {
    position: absolute;
    opacity: 0;
    width: 100%;
    height: 100%;
    cursor: pointer;
}

.btn {
    display: inline-block;
    padding: 12px 30px;
    background-color: var(--accent);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
}

.btn:hover:not(:disabled) {
    background-color: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn-secondary {
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    border: 1px solid var(--border);
}

.btn-secondary:hover:not(:disabled) {
    background-color: var(--border);
}

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

.btn-success:hover:not(:disabled) {
    background-color: #38A169;
}

.info-text {
    text-align: center;
    color: var(--text-secondary);
    font-size: 14px;
    margin-bottom: 30px;
}

.actions {
    display: flex;
    gap: 15px;
    justify-content: center;
    margin-bottom: 30px;
    flex-wrap: wrap;
}

.files-list {
    background-color: var(--bg-secondary);
    border-radius: 12px;
    padding: 20px;
    margin-bottom: 40px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.files-list-header {
    display: grid;
    grid-template-columns: 2fr 1fr 1.5fr 1.5fr;
    gap: 15px;
    padding: 15px;
    font-weight: 600;
    color: var(--text-secondary);
    border-bottom: 2px solid var(--border);
    margin-bottom: 10px;
}

.file-item {
    display: grid;
    grid-template-columns: 2fr 1fr 1.5fr 1.5fr;
    gap: 15px;
    padding: 15px;
    border-bottom: 1px solid var(--border);
    align-items: center;
    transition: background-color 0.2s ease;
}

.file-item:hover {
    background-color: var(--dropzone-bg);
}

.file-item:last-child {
    border-bottom: none;
}

.file-name {
    font-weight: 500;
    color: var(--text-primary);
    word-break: break-word;
}

.file-size {
    color: var(--text-secondary);
    font-size: 14px;
}

.file-status {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 14px;
}

.status-pending {
    color: var(--text-secondary);
}

.status-converting {
    color: var(--accent);
}

.status-ready {
    color: var(--success);
}

.status-error {
    color: var(--error);
}

.file-actions {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.btn-small {
    padding: 6px 12px;
    font-size: 14px;
}

.btn-icon {
    background: none;
    border: none;
    color: var(--error);
    cursor: pointer;
    font-size: 18px;
    padding: 5px;
    transition: transform 0.2s ease;
}

.btn-icon:hover {
    transform: scale(1.2);
}

.info-section {
    background-color: var(--bg-secondary);
    border-radius: 12px;
    padding: 40px;
    margin-top: 60px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.info-section h2 {
    font-size: 28px;
    margin-bottom: 20px;
    color: var(--text-primary);
}

.info-section p {
    color: var(--text-secondary);
    margin-bottom: 15px;
    line-height: 1.8;
}

.progress-bar {
    width: 100%;
    height: 6px;
    background-color: var(--border);
    border-radius: 3px;
    overflow: hidden;
    margin-top: 20px;
}

.progress-fill {
    height: 100%;
    background-color: var(--accent);
    transition: width 0.3s ease;
}

.message {
    padding: 12px 20px;
    border-radius: 8px;
    margin-bottom: 20px;
    display: none;
}

.message.error {
    background-color: rgba(245, 101, 101, 0.1);
    color: var(--error);
    border: 1px solid var(--error);
    display: block;
}

.message.success {
    background-color: rgba(72, 187, 120, 0.1);
    color: var(--success);
    border: 1px solid var(--success);
    display: block;
}

@media (max-width: 768px) {
    h1 {
        font-size: 28px;
    }

    .dropzone {
        padding: 40px 15px;
    }

    .files-list-header,
    .file-item {
        grid-template-columns: 1fr;
        gap: 10px;
    }

    .files-list-header {
        display: none;
    }

    .file-item {
        border: 1px solid var(--border);
        border-radius: 8px;
        margin-bottom: 10px;
        padding: 15px;
    }

    .file-name::before {
        content: "Файл: ";
        font-weight: 600;
    }

    .file-size::before {
        content: "Размер: ";
        font-weight: 600;
    }

    .file-status::before {
        content: "Статус: ";
        font-weight: 600;
    }

    .actions {
        flex-direction: column;
    }

    .btn {
        width: 100%;
    }
}