/* Root Tokens & Design System */
:root {
    --bg-color: #0d1117;
    --card-bg: #161b22;
    --card-border: #30363d;
    --card-hover-border: #58a6ff;
    
    --text-main: #c9d1d9;
    --text-muted: #8b949e;
    --text-heading: #f0f6fc;
    
    --accent-blue: #58a6ff;
    --accent-purple: #bc8cff;
    --accent-green: #3fb950;
    --accent-red: #f85149;
    --pdf-red: #ff4757;
    
    --btn-primary-bg: #238636;
    --btn-primary-hover: #2ea043;
    --btn-secondary-bg: #21262d;
    --btn-secondary-border: #30363d;
    --btn-secondary-hover: #30363d;
    
    --code-bg: #161b22;
    --table-border: #30363d;
    --table-stripe: #161b22;
    
    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
    --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-main);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* App Container */
.app-container {
    max-width: 1200px;
    width: 100%;
    margin: 0 auto;
    padding: 24px 20px;
    display: flex;
    flex-direction: column;
    gap: 24px;
    flex: 1;
}

/* Header */
.app-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 24px;
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    backdrop-filter: blur(10px);
}

.header-brand {
    display: flex;
    align-items: center;
    gap: 16px;
}

.brand-logo {
    font-size: 2rem;
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--text-heading);
}

.pdf-accent {
    color: var(--pdf-red);
}

.brand-text h1 {
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--text-heading);
    letter-spacing: -0.5px;
}

.badge {
    font-size: 0.75rem;
    font-weight: 600;
    padding: 2px 8px;
    background: rgba(88, 166, 255, 0.15);
    color: var(--accent-blue);
    border: 1px solid rgba(88, 166, 255, 0.3);
    border-radius: 12px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.header-info {
    display: flex;
    gap: 12px;
}

.info-tag {
    font-size: 0.85rem;
    color: var(--text-muted);
    background: rgba(255, 255, 255, 0.05);
    padding: 6px 12px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--card-border);
}

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

/* Upload Section */
.upload-section {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

/* Drop Zone */
.drop-zone {
    position: relative;
    border: 2px dashed var(--card-border);
    border-radius: var(--radius-md);
    padding: 40px 20px;
    text-align: center;
    background: rgba(13, 17, 23, 0.5);
    transition: var(--transition);
    cursor: pointer;
}

.drop-zone:hover, .drop-zone.dragover {
    border-color: var(--accent-blue);
    background: rgba(88, 166, 255, 0.04);
}

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

.upload-icon {
    font-size: 3rem;
    color: var(--accent-blue);
    margin-bottom: 12px;
}

.drop-zone h3 {
    font-size: 1.2rem;
    color: var(--text-heading);
    margin-bottom: 6px;
}

.drop-zone p {
    color: var(--text-muted);
    font-size: 0.95rem;
    margin-bottom: 10px;
}

.browse-btn {
    color: var(--accent-blue);
    text-decoration: underline;
    font-weight: 600;
}

.file-hint {
    font-size: 0.8rem;
    color: var(--text-muted);
    display: block;
}

/* File Preview Banner */
.file-preview-banner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 20px;
    background: rgba(33, 38, 45, 0.8);
    border: 1px solid var(--accent-blue);
    border-radius: var(--radius-md);
    position: relative;
    z-index: 10;
}

.file-info {
    display: flex;
    align-items: center;
    gap: 14px;
}

.file-icon {
    font-size: 2rem;
    color: var(--pdf-red);
}

.file-details {
    display: flex;
    flex-direction: column;
    text-align: left;
}

.file-name {
    font-weight: 600;
    color: var(--text-heading);
    font-size: 1.05rem;
}

.file-size {
    font-size: 0.85rem;
    color: var(--text-muted);
}

.btn-remove {
    background: transparent;
    border: none;
    color: var(--text-muted);
    font-size: 1.2rem;
    cursor: pointer;
    padding: 8px;
    border-radius: 50%;
    transition: var(--transition);
}

.btn-remove:hover {
    color: var(--accent-red);
    background: rgba(248, 81, 73, 0.15);
}

/* Settings Bar */
.settings-bar {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 16px;
    padding-top: 8px;
    border-top: 1px solid var(--card-border);
}

.setting-item {
    display: flex;
    align-items: center;
    gap: 14px;
    background: rgba(13, 17, 23, 0.4);
    padding: 12px 16px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--card-border);
}

.toggle-switch {
    position: relative;
    display: inline-block;
    width: 44px;
    height: 24px;
    flex-shrink: 0;
}

.toggle-switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    position: absolute;
    cursor: pointer;
    top: 0; left: 0; right: 0; bottom: 0;
    background-color: var(--card-border);
    transition: .3s;
    border-radius: 24px;
}

.slider:before {
    position: absolute;
    content: "";
    height: 18px;
    width: 18px;
    left: 3px;
    bottom: 3px;
    background-color: white;
    transition: .3s;
    border-radius: 50%;
}

input:checked + .slider {
    background-color: var(--accent-blue);
}

input:checked + .slider:before {
    transform: translateX(20px);
}

.setting-label {
    display: flex;
    flex-direction: column;
}

.setting-label strong {
    font-size: 0.9rem;
    color: var(--text-heading);
}

.setting-label small {
    font-size: 0.75rem;
    color: var(--text-muted);
}

/* Convert Button & Action Bar */
.action-bar {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.btn-convert {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    width: 100%;
    padding: 14px 28px;
    font-size: 1.05rem;
    font-weight: 600;
    color: #ffffff;
    background: var(--btn-primary-bg);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: var(--transition);
    box-shadow: 0 4px 14px rgba(35, 134, 54, 0.4);
}

.btn-convert:hover:not(.disabled) {
    background: var(--btn-primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(35, 134, 54, 0.6);
}

.btn-convert.btn-back {
    background: rgba(248, 81, 73, 0.15);
    color: #ff6b6b;
    border: 1px solid rgba(248, 81, 73, 0.4);
    box-shadow: 0 4px 14px rgba(248, 81, 73, 0.2);
}

.btn-convert.btn-back:hover {
    background: #da3633;
    color: #ffffff;
    border-color: rgba(255, 255, 255, 0.2);
    box-shadow: 0 6px 20px rgba(218, 54, 51, 0.5);
    transform: translateY(-2px);
}

.btn-convert.disabled {
    opacity: 0.4;
    cursor: not-allowed;
    box-shadow: none;
}

/* Loading Overlay */
.loading-overlay {
    padding: 30px;
    text-align: center;
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: var(--radius-lg);
}

.spinner-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
}

.spinner {
    width: 48px;
    height: 48px;
    border: 4px solid rgba(88, 166, 255, 0.2);
    border-top: 4px solid var(--accent-blue);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

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

/* Error Banner */
.error-banner {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 14px 20px;
    background: rgba(248, 81, 73, 0.15);
    border: 1px solid var(--accent-red);
    border-radius: var(--radius-md);
    color: var(--accent-red);
    font-weight: 500;
}

/* Workspace Section */
.workspace-section {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.stats-bar {
    display: flex;
    gap: 24px;
    padding-bottom: 16px;
    border-bottom: 1px solid var(--card-border);
}

.stat-item {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.9rem;
    color: var(--text-muted);
}

.stat-item i {
    color: var(--accent-blue);
}

.stat-item strong {
    color: var(--text-heading);
}

.workspace-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 16px;
}

.tabs {
    display: flex;
    gap: 8px;
    background: rgba(13, 17, 23, 0.6);
    padding: 4px;
    border-radius: var(--radius-md);
    border: 1px solid var(--card-border);
}

.tab-btn {
    padding: 8px 16px;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-muted);
    background: transparent;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
}

.tab-btn.active {
    color: var(--text-heading);
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    box-shadow: 0 2px 8px rgba(0,0,0,0.3);
}

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

.btn-primary, .btn-secondary, .btn-outline {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 16px;
    font-size: 0.9rem;
    font-weight: 600;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
}

.btn-primary {
    background: var(--btn-primary-bg);
    color: #ffffff;
    border: 1px solid rgba(255,255,255,0.1);
}

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

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

.btn-secondary:hover {
    background: var(--btn-secondary-hover);
    border-color: var(--accent-blue);
    color: var(--text-heading);
}

.btn-outline {
    background: transparent;
    color: var(--accent-purple);
    border: 1px solid rgba(188, 140, 255, 0.4);
}

.btn-outline:hover {
    background: rgba(188, 140, 255, 0.1);
    border-color: var(--accent-purple);
}

/* Tab Content */
.tab-content {
    min-height: 450px;
    max-height: 700px;
    overflow-y: auto;
    border: 1px solid var(--card-border);
    border-radius: var(--radius-md);
    background: #0d1117;
    padding: 24px;
}

.tab-pane {
    display: none;
}

.tab-pane.active {
    display: block;
}

/* Rendered GFM Styling */
.markdown-body {
    color: #c9d1d9;
    font-size: 1rem;
    line-height: 1.7;
}

.markdown-body h1, .markdown-body h2, .markdown-body h3, .markdown-body h4 {
    color: #f0f6fc;
    margin-top: 24px;
    margin-bottom: 12px;
    font-weight: 600;
    line-height: 1.25;
    border-bottom: 1px solid #21262d;
    padding-bottom: 8px;
}

.markdown-body p {
    margin-bottom: 16px;
}

.markdown-body ul, .markdown-body ol {
    margin-bottom: 16px;
    padding-left: 24px;
}

.markdown-body li {
    margin-bottom: 4px;
}

.markdown-body table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 20px;
    overflow: x-auto;
    display: block;
}

.markdown-body th, .markdown-body td {
    padding: 8px 16px;
    border: 1px solid #30363d;
}

.markdown-body th {
    background-color: #161b22;
    font-weight: 600;
    color: #f0f6fc;
}

.markdown-body tr:nth-child(even) {
    background-color: #161b22;
}

.markdown-body img {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
    margin: 16px 0;
    box-shadow: 0 4px 12px rgba(0,0,0,0.5);
    border: 1px solid #30363d;
}

.markdown-body blockquote {
    padding: 0 1em;
    color: #8b949e;
    border-left: 0.25em solid #30363d;
    margin-bottom: 16px;
}

.markdown-body pre {
    background-color: #161b22;
    border-radius: 6px;
    padding: 16px;
    overflow: auto;
    margin-bottom: 16px;
}

.markdown-body code {
    font-family: 'Fira Code', monospace;
    font-size: 0.9em;
    background: rgba(110, 118, 129, 0.4);
    padding: 2px 6px;
    border-radius: 4px;
}

.markdown-body pre code {
    background: transparent;
    padding: 0;
}

/* Raw Markdown Textarea */
.raw-markdown-wrapper {
    height: 100%;
    width: 100%;
}

#rawMarkdownTextarea {
    width: 100%;
    height: 500px;
    background: transparent;
    color: #c9d1d9;
    font-family: 'Fira Code', monospace;
    font-size: 0.9rem;
    line-height: 1.6;
    border: none;
    outline: none;
    resize: vertical;
}

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

/* Footer */
.app-footer {
    text-align: center;
    padding: 16px;
    font-size: 0.85rem;
    color: var(--text-muted);
}