/* ============================================
   CSS Variables & Reset - Light Theme (Blue)
   ============================================ */
:root {
    /* Colors - Light Theme with Blue accent */
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --bg-elevated: #ffffff;
    
    --surface-glass: rgba(0, 0, 0, 0.02);
    --surface-glass-hover: rgba(0, 0, 0, 0.04);
    --border-default: #e2e8f0;
    --border-strong: #cbd5e1;
    
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-tertiary: #94a3b8;
    
    /* Blue accent colors */
    --accent-primary: #2563eb;
    --accent-primary-hover: #1d4ed8;
    --accent-light: #eff6ff;
    --accent-gradient: linear-gradient(135deg, #2563eb 0%, #3b82f6 100%);
    
    --success: #10b981;
    --warning: #f59e0b;
    --error: #ef4444;
    --info: #3b82f6;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);
    
    /* Typography */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', Consolas, monospace;
    
    /* Spacing */
    --space-xs: 4px;
    --space-sm: 8px;
    --space-md: 16px;
    --space-lg: 24px;
    --space-xl: 32px;
    --space-2xl: 48px;
    
    /* Border Radius */
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    
    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-base: 0.25s ease;
}

[data-theme="dark"] {
    --bg-primary: #0f172a;
    --bg-secondary: #020617;
    --bg-tertiary: #1e293b;
    --bg-elevated: #1e293b;
    
    --surface-glass: rgba(255, 255, 255, 0.03);
    --surface-glass-hover: rgba(255, 255, 255, 0.05);
    --border-default: #334155;
    --border-strong: #475569;
    
    --text-primary: #cbd5e1;
    --text-secondary: #94a3b8;
    --text-tertiary: #64748b;
    
    --accent-light: rgba(37, 99, 235, 0.1);
    
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.5);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.7);
}

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

html, body {
    height: 100%;
}

body {
    font-family: var(--font-sans);
    background: var(--bg-secondary);
    color: var(--text-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

/* ============================================
   App & Page Layout
   ============================================ */
.app {
    height: 100%;
}

.page {
    display: none;
    height: 100%;
}

.page.active {
    display: flex;
    flex-direction: column;
}

/* ============================================
   Page 1: Input Page
   ============================================ */
.page-input {
    align-items: center;
    justify-content: center;
    padding: var(--space-lg);
    overflow-y: auto;
}

.header {
    text-align: center;
    margin-bottom: var(--space-xl);
}

.logo {
    display: inline-flex;
    align-items: center;
    gap: var(--space-md);
    margin-bottom: var(--space-sm);
}

.logo-icon {
    width: 36px;
    height: 36px;
    color: var(--accent-primary);
}

.logo h1 {
    font-size: 1.75rem;
    font-weight: 700;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.tagline {
    color: var(--text-secondary);
    font-size: 0.9375rem;
}

.input-main {
    width: 100%;
    max-width: 560px;
}

/* Input Cards */
.input-card {
    background: var(--bg-primary);
    border: 1px solid var(--border-default);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    box-shadow: var(--shadow-sm);
}

.card-header {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    margin-bottom: var(--space-md);
    color: var(--text-secondary);
}

.card-header svg {
    width: 18px;
    height: 18px;
    color: var(--accent-primary);
}

.card-header h2 {
    font-size: 0.8125rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* URL Input */
.url-input-wrapper {
    display: flex;
    gap: var(--space-sm);
}

.url-input-wrapper input {
    flex: 1;
    padding: var(--space-sm) var(--space-md);
    background: var(--bg-secondary);
    border: 1px solid var(--border-default);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-size: 0.9375rem;
    font-family: var(--font-mono);
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.url-input-wrapper input:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

.url-input-wrapper input::placeholder {
    color: var(--text-tertiary);
}

/* History Section */
.history-section {
    margin-top: var(--space-md);
    display: none;
}

.history-section.visible {
    display: block;
}

.history-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--space-sm);
}

.history-title {
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--text-tertiary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.btn-text {
    background: none;
    border: none;
    color: var(--error);
    font-size: 0.75rem;
    cursor: pointer;
    padding: 0;
}

.btn-text:hover {
    text-decoration: underline;
}

.history-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
    max-height: 200px;
    overflow-y: auto;
    padding-right: 4px; /* Space for scrollbar */
}

/* Custom Scrollbar for history list */
.history-list::-webkit-scrollbar {
    width: 4px;
}

.history-list::-webkit-scrollbar-track {
    background: transparent;
}

.history-list::-webkit-scrollbar-thumb {
    background: var(--border-default);
    border-radius: 4px;
}

.history-list::-webkit-scrollbar-thumb:hover {
    background: var(--text-tertiary);
}

.history-item {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm) var(--space-md);
    background: var(--bg-secondary);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: background var(--transition-fast);
}

.history-item:hover {
    background: var(--accent-light);
}

.history-item-url {
    flex: 1;
    font-family: var(--font-mono);
    font-size: 0.8125rem;
    color: var(--text-primary);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.history-item-time {
    font-size: 0.75rem;
    color: var(--text-tertiary);
    white-space: nowrap;
}

.history-item-delete {
    width: 16px;
    height: 16px;
    color: var(--text-tertiary);
    cursor: pointer;
    opacity: 0;
    transition: opacity var(--transition-fast), color var(--transition-fast);
}

.history-item:hover .history-item-delete {
    opacity: 1;
}

.history-item-delete:hover {
    color: var(--error);
}

/* Divider */
.divider {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    margin: var(--space-lg) 0;
    color: var(--text-tertiary);
    font-size: 0.8125rem;
}

.divider::before,
.divider::after {
    content: '';
    flex: 1;
    height: 1px;
    background: var(--border-default);
}

/* File Drop Zone */
.file-drop-zone {
    border: 2px dashed var(--border-strong);
    border-radius: var(--radius-md);
    padding: var(--space-xl);
    text-align: center;
    cursor: pointer;
    transition: all var(--transition-base);
    background: var(--bg-secondary);
}

.file-drop-zone:hover,
.file-drop-zone.dragover {
    border-color: var(--accent-primary);
    background: var(--accent-light);
}

.drop-content svg {
    width: 40px;
    height: 40px;
    color: var(--text-tertiary);
    margin-bottom: var(--space-sm);
}

.drop-content p {
    color: var(--text-secondary);
    margin-bottom: var(--space-xs);
    font-size: 0.9375rem;
}

.browse-link {
    color: var(--accent-primary);
    font-weight: 500;
    text-decoration: underline;
    cursor: pointer;
}

.supported-formats {
    font-size: 0.75rem;
    color: var(--text-tertiary);
}

/* ============================================
   Buttons
   ============================================ */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-xs);
    padding: var(--space-sm) var(--space-md);
    border: none;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
    white-space: nowrap;
}

.btn svg {
    width: 16px;
    height: 16px;
}

.btn-primary {
    background: var(--accent-gradient);
    color: white;
    box-shadow: var(--shadow-sm);
}

.btn-primary:hover:not(:disabled) {
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn-primary:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

/* Small button variant */
.btn-sm {
    padding: var(--space-xs) var(--space-sm);
    font-size: 0.8125rem;
}

.btn-sm svg {
    width: 14px;
    height: 14px;
}

.btn-ghost {
    background: transparent;
    color: var(--text-secondary);
    padding: var(--space-xs) var(--space-sm);
}

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

.btn-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    background: transparent;
    border: 1px solid var(--border-default);
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.btn-icon svg {
    width: 16px;
    height: 16px;
}

.btn-icon:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border-color: var(--border-strong);
}

/* Loading State */
.btn.loading svg {
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

/* ============================================
   Page 2: Preview Page
   ============================================ */
.page-preview {
    background: var(--bg-primary);
}

/* Toolbar */
.toolbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-xs) var(--space-md);
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-default);
    height: 48px;
    flex-shrink: 0;
}

.toolbar-left,
.toolbar-right {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.toolbar-center {
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
}

.file-name {
    font-family: var(--font-mono);
    font-size: 0.8125rem;
    color: var(--text-secondary);
    padding: var(--space-xs) var(--space-sm);
    background: var(--bg-tertiary);
    border-radius: var(--radius-sm);
    max-width: 200px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

/* View Tabs */
.view-tabs {
    display: flex;
    background: var(--bg-tertiary);
    border-radius: var(--radius-sm);
    padding: 2px;
}

.view-tabs .tab {
    padding: var(--space-xs) var(--space-md);
    background: transparent;
    border: none;
    border-radius: var(--radius-sm);
    color: var(--text-tertiary);
    font-size: 0.75rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.view-tabs .tab:hover {
    color: var(--text-secondary);
}

.view-tabs .tab.active {
    background: var(--bg-primary);
    color: var(--text-primary);
    box-shadow: var(--shadow-sm);
}

/* Preview Main */
.preview-main {
    flex: 1;
    display: flex;
    overflow: hidden;
}

/* Panels */
.preview-panel {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    transition: flex var(--transition-base);
}

.preview-panel.full {
    flex: 1;
}

.preview-panel.half {
    flex: 0 0 50%;
    border-right: 1px solid var(--border-default);
}

.result-panel {
    flex: 0 0 50%;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.result-panel.hidden {
    display: none;
}

.panel-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-xs) var(--space-md);
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-default);
    height: 40px;
}

.panel-header h3 {
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--text-secondary);
}

.panel-actions {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
}

.panel-content {
    flex: 1;
    overflow: hidden;
    position: relative;
    display: flex;
    flex-direction: column;
}

/* Views */
.code-view {
    width: 100%;
    height: 100%;
    padding: var(--space-md);
    font-family: var(--font-mono);
    font-size: 0.8125rem;
    line-height: 1.7;
    white-space: pre-wrap;
    word-break: break-word;
    color: var(--text-primary);
    background: var(--bg-secondary);
    overflow: auto;
    margin: 0;
}

.render-view {
    width: 100%;
    height: 100%;
    border: none;
    background: white;
}

.render-view.hidden,
.code-view.hidden {
    display: none;
}

/* ============================================
   Markdown Preview Styles
   ============================================ */
.markdown-body {
    padding: var(--space-lg);
    background: var(--bg-primary);
    color: var(--text-primary);
    font-size: 1rem;
    line-height: 1.7;
    overflow-y: auto;
    flex: 1;
}

.markdown-body h1, .markdown-body h2, .markdown-body h3,
.markdown-body h4, .markdown-body h5, .markdown-body h6 {
    margin-top: 1.5em;
    margin-bottom: 0.5em;
    font-weight: 600;
    line-height: 1.3;
}

.markdown-body h1:first-child,
.markdown-body h2:first-child,
.markdown-body h3:first-child {
    margin-top: 0;
}

.markdown-body h1 { font-size: 1.75em; border-bottom: 1px solid var(--border-default); padding-bottom: 0.3em; }
.markdown-body h2 { font-size: 1.4em; border-bottom: 1px solid var(--border-default); padding-bottom: 0.3em; }
.markdown-body h3 { font-size: 1.2em; }

.markdown-body p {
    margin-bottom: 1em;
}

.markdown-body a {
    color: var(--accent-primary);
    text-decoration: none;
}

.markdown-body a:hover {
    text-decoration: underline;
}

.markdown-body code {
    font-family: var(--font-mono);
    background: var(--bg-tertiary);
    padding: 0.2em 0.4em;
    border-radius: 4px;
    font-size: 0.9em;
}

.markdown-body pre {
    background: var(--bg-tertiary);
    padding: var(--space-md);
    border-radius: var(--radius-md);
    overflow-x: auto;
    margin-bottom: 1em;
}

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

.markdown-body blockquote {
    border-left: 4px solid var(--accent-primary);
    padding-left: var(--space-md);
    margin-left: 0;
    color: var(--text-secondary);
}

.markdown-body ul, .markdown-body ol {
    padding-left: 2em;
    margin-bottom: 1em;
}

.markdown-body li {
    margin-bottom: 0.25em;
}

.markdown-body table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 1em;
}

.markdown-body th, .markdown-body td {
    border: 1px solid var(--border-default);
    padding: var(--space-sm) var(--space-md);
    text-align: left;
}

.markdown-body th {
    background: var(--bg-tertiary);
    font-weight: 600;
}

.markdown-body img {
    max-width: 100%;
    border-radius: var(--radius-md);
}

.markdown-body hr {
    border: none;
    border-top: 1px solid var(--border-default);
    margin: 2em 0;
}

/* KaTeX styles override */
.markdown-body .katex-display {
    margin: 1em 0;
    overflow-x: auto;
}

/* ============================================
   Toast Notification
   ============================================ */
.toast {
    position: fixed;
    bottom: var(--space-lg);
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--text-primary);
    color: var(--bg-primary);
    padding: var(--space-sm) var(--space-md);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    opacity: 0;
    transition: all var(--transition-base);
    z-index: 1000;
    font-size: 0.875rem;
}

.toast.visible {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
}

.toast.success {
    background: var(--success);
}

.toast.error {
    background: var(--error);
}

/* ============================================
   Responsive
   ============================================ */
/* ============================================
   Auth Modal
   ============================================ */
.auth-modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--bg-primary); /* Full cover */
    z-index: 2000;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition-base);
}

.auth-modal-overlay.visible {
    opacity: 1;
    pointer-events: auto;
}

.auth-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-default);
    padding: var(--space-2xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    width: 100%;
    max-width: 360px;
    text-align: center;
}

.auth-icon {
    width: 48px;
    height: 48px;
    background: var(--accent-light);
    color: var(--accent-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto var(--space-md);
}

.auth-icon svg {
    width: 24px;
    height: 24px;
}

.auth-card h2 {
    margin-bottom: var(--space-sm);
    color: var(--text-primary);
}

.auth-card p {
    color: var(--text-secondary);
    font-size: 0.9375rem;
    margin-bottom: var(--space-lg);
}

.auth-input-group {
    display: flex;
    gap: var(--space-sm);
    margin-bottom: var(--space-sm);
}

.auth-input-group input {
    flex: 1;
    padding: var(--space-sm) var(--space-md);
    background: var(--bg-primary);
    border: 1px solid var(--border-default);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-size: 1rem;
    transition: all var(--transition-fast);
}

.auth-input-group input:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

.auth-input-group button {
    width: 42px;
    background: var(--accent-primary);
    color: white;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background var(--transition-fast);
}

.auth-input-group button:hover {
    background: var(--accent-primary-hover);
}

.auth-error {
    color: var(--error);
    font-size: 0.8125rem;
    min-height: 1.2em;
    margin-bottom: 0 !important;
}

/* ============================================
   Responsive
   ============================================ */
@media (max-width: 768px) {
    .toolbar {
        padding: var(--space-xs);
    }
    
    .toolbar-center {
        display: none;
    }
    
    .preview-main {
        flex-direction: column;
    }
    
    .preview-panel.half {
        flex: 0 0 50%;
        border-right: none;
        border-bottom: 1px solid var(--border-default);
    }
    
    .result-panel {
        flex: 0 0 50%;
    }
    
    .url-input-wrapper {
        flex-direction: column;
    }
}
}