/* Modern Design System for YouTube Downloader */
:root {
    --bg-primary: #0f141c;
    --bg-secondary: #171e29;
    --bg-card: #1c2433;
    --bg-card-hover: #222c3d;
    --bg-input: #121822;
    
    --border-color: #2b3548;
    --border-focus: #3d82e2;
    
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    
    --accent: #3b82f6;
    --accent-hover: #2563eb;
    --accent-subtle: rgba(59, 130, 246, 0.12);
    
    --success: #10b981;
    --success-bg: rgba(16, 185, 129, 0.12);
    --warning: #f59e0b;
    --warning-bg: rgba(245, 158, 11, 0.12);
    --danger: #ef4444;
    --danger-bg: rgba(239, 68, 68, 0.12);
    
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 14px;
    
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.25);
    --shadow-md: 0 4px 12px -2px rgba(0, 0, 0, 0.35);
    --shadow-lg: 0 12px 28px -4px rgba(0, 0, 0, 0.5);
    
    --transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

/* App Layout */
.app-layout {
    display: flex;
    min-height: 100vh;
}

/* Sidebar */
.sidebar {
    width: 260px;
    background-color: var(--bg-secondary);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    padding: 24px 16px;
    flex-shrink: 0;
}

.brand {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 32px;
    padding: 0 8px;
}

.brand-icon {
    width: 40px;
    height: 40px;
    background: var(--accent);
    color: #fff;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-sm);
}

.brand-text h2 {
    font-size: 1.1rem;
    font-weight: 700;
    letter-spacing: -0.02em;
}

.version-tag {
    font-size: 0.68rem;
    font-weight: 600;
    color: var(--accent);
    background: var(--accent-subtle);
    padding: 2px 6px;
    border-radius: 4px;
}

.nav-menu {
    display: flex;
    flex-direction: column;
    gap: 6px;
    flex-grow: 1;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 14px;
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-size: 0.92rem;
    font-weight: 500;
    border-radius: var(--radius-md);
    cursor: pointer;
    text-align: left;
    transition: var(--transition);
    width: 100%;
}

.nav-item:hover {
    background-color: var(--bg-card);
    color: var(--text-primary);
}

.nav-item.active {
    background-color: var(--accent);
    color: #fff;
    font-weight: 600;
}

.nav-item .badge {
    margin-left: auto;
    background: var(--bg-primary);
    color: var(--text-primary);
    font-size: 0.75rem;
    padding: 2px 8px;
    border-radius: 12px;
    font-weight: 600;
}

.nav-item.active .badge {
    background: rgba(255, 255, 255, 0.25);
    color: #fff;
}

.sidebar-footer {
    padding-top: 16px;
    border-top: 1px solid var(--border-color);
}

.ws-status-indicator {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.8rem;
    color: var(--text-muted);
}

.status-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background-color: var(--warning);
    transition: var(--transition);
}

.status-dot.connected {
    background-color: var(--success);
}

/* Main Content */
.main-content {
    flex-grow: 1;
    padding: 36px 48px;
    max-width: 1100px;
    overflow-y: auto;
}

.tab-pane {
    display: none;
}

.tab-pane.active {
    display: block;
    animation: fadeIn 0.25s ease-out;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(6px); }
    to { opacity: 1; transform: translateY(0); }
}

.section-header {
    margin-bottom: 28px;
}

.section-header.flex-between {
    display: flex;
    justify-content: space-between;
    align-items: flex-end;
}

.section-header h1 {
    font-size: 1.75rem;
    font-weight: 700;
    letter-spacing: -0.03em;
    margin-bottom: 6px;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* Cards */
.card {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 24px;
    box-shadow: var(--shadow-md);
}

/* Download Form */
.url-input-group {
    display: flex;
    gap: 12px;
    margin-bottom: 20px;
}

.input-wrapper {
    flex-grow: 1;
    position: relative;
    display: flex;
    align-items: center;
}

.input-wrapper svg {
    position: absolute;
    left: 14px;
    color: var(--text-muted);
}

.input-wrapper input {
    width: 100%;
    padding: 14px 14px 14px 44px;
    background-color: var(--bg-input);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 0.95rem;
    font-family: inherit;
    transition: var(--transition);
}

.input-wrapper input:focus {
    outline: none;
    border-color: var(--border-focus);
    box-shadow: 0 0 0 2px var(--accent-subtle);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 10px 20px;
    border-radius: var(--radius-md);
    font-size: 0.92rem;
    font-weight: 600;
    cursor: pointer;
    border: 1px solid transparent;
    transition: var(--transition);
    font-family: inherit;
}

.btn-primary {
    background-color: var(--accent);
    color: #fff;
}

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

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

.btn-secondary:hover {
    background-color: var(--bg-card-hover);
}

.btn-danger {
    background-color: var(--danger-bg);
    color: var(--danger);
    border-color: rgba(239, 68, 68, 0.2);
}

.btn-danger:hover {
    background-color: var(--danger);
    color: #fff;
}

.btn-large {
    padding: 14px 28px;
    font-size: 1rem;
    width: 100%;
}

.btn-sm {
    padding: 6px 12px;
    font-size: 0.82rem;
}

/* Media Preview */
.media-preview {
    display: flex;
    gap: 20px;
    padding: 16px;
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    margin-bottom: 24px;
    align-items: center;
}

.preview-thumb-wrapper {
    position: relative;
    width: 180px;
    height: 100px;
    border-radius: var(--radius-sm);
    overflow: hidden;
    flex-shrink: 0;
    background: #000;
}

.preview-thumb-wrapper img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.duration-badge {
    position: absolute;
    bottom: 6px;
    right: 6px;
    background: rgba(0, 0, 0, 0.8);
    color: #fff;
    font-size: 0.72rem;
    padding: 2px 6px;
    border-radius: 4px;
    font-family: 'JetBrains Mono', monospace;
}

.preview-info h3 {
    font-size: 1.05rem;
    font-weight: 600;
    margin-bottom: 6px;
    line-height: 1.35;
}

.preview-meta {
    display: flex;
    gap: 12px;
    color: var(--text-secondary);
    font-size: 0.82rem;
}

/* Mode toggle */
.mode-toggle {
    display: flex;
    gap: 8px;
    margin-top: 8px;
    margin-bottom: 20px;
}

.mode-btn {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    padding: 12px;
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    font-size: 0.92rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
}

.mode-btn:hover {
    background-color: var(--bg-card-hover);
    color: var(--text-primary);
}

.mode-btn.active {
    border-color: var(--accent);
    background-color: var(--accent-subtle);
    color: var(--text-primary);
    font-weight: 600;
}

.form-label {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-secondary);
}

/* Options Grid */
.options-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 16px;
    margin-bottom: 20px;
}

/* Interactive Available Format Chips */
.available-formats-container {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 16px;
    margin-bottom: 20px;
}

.format-chips-section {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-top: 10px;
}

.chips-group {
    display: flex;
    align-items: center;
    gap: 10px;
    flex-wrap: wrap;
}

.chips-label {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-muted);
    min-width: 70px;
}

.chips-list {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

.format-chip {
    padding: 6px 14px;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    color: var(--text-primary);
    font-size: 0.82rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 6px;
    user-select: none;
}

.format-chip:hover {
    border-color: var(--accent);
    background-color: var(--bg-card-hover);
    transform: translateY(-1px);
}

.format-chip.active {
    background-color: var(--accent);
    border-color: var(--accent);
    color: #fff;
    font-weight: 600;
    box-shadow: 0 0 10px rgba(99, 102, 241, 0.4);
}

.format-chip .chip-badge {
    font-size: 0.7rem;
    padding: 1px 5px;
    border-radius: 10px;
    background: rgba(255, 255, 255, 0.2);
}

.form-group {
    margin-bottom: 16px;
}

.form-group label {
    display: block;
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 6px;
}

.form-control {
    width: 100%;
    padding: 10px 12px;
    background-color: var(--bg-input);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 0.9rem;
    font-family: inherit;
    transition: var(--transition);
}

.form-control:focus {
    outline: none;
    border-color: var(--border-focus);
}

/* Accordion */
.advanced-details {
    margin-bottom: 24px;
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    overflow: hidden;
}

.advanced-details summary {
    padding: 12px 16px;
    font-size: 0.88rem;
    font-weight: 600;
    cursor: pointer;
    user-select: none;
    color: var(--text-secondary);
}

.advanced-details summary:hover {
    color: var(--text-primary);
}

.advanced-body {
    padding: 16px;
    border-top: 1px solid var(--border-color);
}

.checkbox-row {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    margin-bottom: 16px;
}

.checkbox-label {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-size: 0.88rem;
    cursor: pointer;
}

/* Tasks List (Queue) */
.tasks-list {
    display: flex;
    flex-direction: column;
    gap: 14px;
}

.task-card {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 18px 20px;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.task-card:hover {
    border-color: #3b475d;
}

.task-header {
    display: flex;
    align-items: flex-start;
    gap: 16px;
    margin-bottom: 14px;
}

.task-thumb {
    width: 68px;
    height: 44px;
    border-radius: var(--radius-sm);
    object-fit: cover;
    background-color: #000;
    flex-shrink: 0;
}

.task-title-area {
    flex-grow: 1;
    min-width: 0;
}

.task-title {
    font-size: 0.96rem;
    font-weight: 600;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    margin-bottom: 4px;
}

.task-sub {
    font-size: 0.8rem;
    color: var(--text-muted);
}

.status-badge {
    font-size: 0.75rem;
    font-weight: 600;
    padding: 4px 10px;
    border-radius: 20px;
    text-transform: uppercase;
    letter-spacing: 0.03em;
}

.status-badge.pending { background: var(--warning-bg); color: var(--warning); }
.status-badge.downloading { background: var(--accent-subtle); color: var(--accent); }
.status-badge.processing { background: rgba(168, 85, 247, 0.15); color: #c084fc; }
.status-badge.completed { background: var(--success-bg); color: var(--success); }
.status-badge.failed { background: var(--danger-bg); color: var(--danger); }
.status-badge.cancelled { background: rgba(100, 116, 139, 0.2); color: var(--text-muted); }

/* Progress Bar */
.progress-bar-container {
    height: 6px;
    background-color: var(--bg-input);
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 10px;
}

.progress-bar-fill {
    height: 100%;
    background-color: var(--accent);
    border-radius: 4px;
    transition: width 0.3s ease;
}

.task-card.completed .progress-bar-fill { background-color: var(--success); }
.task-card.failed .progress-bar-fill { background-color: var(--danger); }

.task-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.82rem;
    color: var(--text-secondary);
    font-family: 'JetBrains Mono', monospace;
}

.task-actions {
    display: flex;
    gap: 8px;
}

/* Collapsible Task Terminal Logs */
.task-terminal-logs {
    margin-top: 14px;
    background-color: #0b0f17;
    border: 1px solid #1e293b;
    border-radius: var(--radius-md);
    overflow: hidden;
}

.terminal-logs-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 6px 12px;
    background-color: #111827;
    border-bottom: 1px solid #1e293b;
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-muted);
}

.btn-copy-logs {
    background: transparent;
    border: 1px solid #374151;
    color: var(--text-secondary);
    padding: 2px 8px;
    border-radius: 4px;
    font-size: 0.7rem;
    cursor: pointer;
    transition: var(--transition);
}

.btn-copy-logs:hover {
    background-color: #1f2937;
    color: #fff;
}

.terminal-logs-body {
    padding: 10px 12px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.75rem;
    line-height: 1.45;
    color: #94a3b8;
    max-height: 180px;
    overflow-y: auto;
    white-space: pre-wrap;
    word-break: break-all;
    margin: 0;
}

/* Files Table */
.files-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.9rem;
}

.files-table th {
    text-align: left;
    padding: 12px 16px;
    color: var(--text-secondary);
    font-size: 0.8rem;
    font-weight: 600;
    border-bottom: 1px solid var(--border-color);
}

.files-table td {
    padding: 14px 16px;
    border-bottom: 1px solid var(--border-color);
}

.files-table tr:hover td {
    background-color: var(--bg-card);
}

/* Additional Action Buttons */
.btn-ghost {
    background: transparent;
    color: var(--text-muted);
    border: 1px solid transparent;
    padding: 6px 10px;
    font-size: 0.78rem;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
}

.btn-ghost:hover {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.06);
    border-color: var(--border-color);
}

.btn-warning {
    background-color: var(--warning-bg);
    color: var(--warning);
    border: 1px solid rgba(245, 158, 11, 0.3);
}

.btn-warning:hover {
    background-color: rgba(245, 158, 11, 0.25);
    color: #fbbf24;
}

.file-actions-group {
    display: flex;
    align-items: center;
    gap: 6px;
    flex-wrap: wrap;
}

.quality-banner {
    display: flex;
    align-items: center;
    gap: 8px;
    background: rgba(59, 130, 246, 0.12);
    border: 1px solid rgba(59, 130, 246, 0.3);
    color: #93c5fd;
    padding: 8px 14px;
    border-radius: var(--radius-md);
    font-size: 0.85rem;
    margin-bottom: 16px;
}

.quality-banner strong {
    color: #fff;
    font-weight: 700;
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: 48px 24px;
    color: var(--text-muted);
}

.empty-state svg {
    margin-bottom: 12px;
}

/* Helper Utilities */
.hidden { display: none !important; }

/* Toast */
.toast-container {
    position: fixed;
    bottom: 24px;
    right: 24px;
    display: flex;
    flex-direction: column;
    gap: 8px;
    z-index: 9999;
}

.toast {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    padding: 12px 18px;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    font-size: 0.88rem;
    animation: slideIn 0.2s ease-out;
}

@keyframes slideIn {
    from { transform: translateX(30px); opacity: 0; }
    to { transform: translateX(0); opacity: 1; }
}

.help-text {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-top: 4px;
    display: block;
}

.status-msg {
    color: var(--success);
    font-size: 0.88rem;
    margin-left: 12px;
}