:root {
    --bg-base: #0A0A14;
    --bg-surface: #13131F;
    --bg-elevated: #1C1C29;
    --border: #2D2D3F;
    
    --text-primary: #F3F4F6;
    --text-secondary: #9CA3AF;
    
    --primary: #A855F7;
    --primary-hover: #9333EA;
    --secondary: #C084FC;
    --accent: #F59E0B;
    
    --diff-add-bg: rgba(16, 185, 129, 0.2);
    --diff-add-text: #34D399;
    --diff-sub-bg: rgba(239, 68, 68, 0.2);
    --diff-sub-text: #F87171;
    
    --radius: 12px;
    --transition: all 0.25s ease;
    --shadow: 0 8px 20px -4px rgba(0, 0, 0, 0.5);
}

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

body {
    font-family: 'Inter', system-ui, sans-serif;
    background-color: var(--bg-base);
    color: var(--text-primary);
    display: flex;
    flex-direction: column;
    height: 100vh;
    overflow: hidden;
}

/* Navbar */
.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 1.5rem;
    background: var(--bg-surface);
    border-bottom: 1px solid var(--border);
    flex-shrink: 0;
}

.brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    color: var(--primary);
}

.brand h1 {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
}

.nav-controls {
    display: flex;
    gap: 0.75rem;
    align-items: center;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    border: 1px solid transparent;
    font-family: inherit;
}

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

.btn-primary:hover {
    background: var(--primary-hover);
    transform: translateY(-1px);
}

.btn-outline {
    background: transparent;
    border-color: var(--border);
    color: var(--text-primary);
}

.btn-outline:hover {
    border-color: var(--text-secondary);
    background: var(--bg-elevated);
}

.btn-ghost {
    background: transparent;
    color: var(--text-secondary);
    padding: 0.5rem;
}

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

.btn-icon {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    font-size: 1rem;
    padding: 4px;
    border-radius: 4px;
    transition: var(--transition);
}

.btn-icon:hover {
    color: var(--primary);
    background: rgba(168, 85, 247, 0.1);
}

/* Layout */
.layout {
    display: flex;
    flex-direction: column;
    flex: 1;
    overflow: hidden;
}

/* Editors */
.editor-section {
    display: flex;
    height: 40%;
    border-bottom: 1px solid var(--border);
    flex-shrink: 0;
}

.pane {
    flex: 1;
    display: flex;
    flex-direction: column;
    background: var(--bg-surface);
}

.pane-original {
    border-right: 1px solid var(--border);
}

.pane-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem 1.5rem;
    border-bottom: 1px solid var(--border);
    background: var(--bg-elevated);
}

.pane-header h2 {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.pane-stats {
    font-size: 0.875rem;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.text-accent {
    color: var(--accent);
    font-weight: 600;
}

textarea {
    flex: 1;
    background: transparent;
    border: none;
    padding: 1.5rem;
    color: var(--text-primary);
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.875rem;
    line-height: 1.6;
    resize: none;
    outline: none;
}

/* Config Bar */
.config-bar {
    display: flex;
    gap: 1.5rem;
    padding: 0.75rem 1.5rem;
    background: var(--bg-surface);
    border-bottom: 1px solid var(--border);
}

.config-group {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.config-group label {
    font-size: 0.875rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.select-input {
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    color: var(--text-primary);
    padding: 0.4rem 2rem 0.4rem 0.75rem;
    border-radius: 6px;
    font-family: inherit;
    font-size: 0.875rem;
    cursor: pointer;
    outline: none;
    appearance: none;
    background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%239CA3AF' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3e%3cpolyline points='6 9 12 15 18 9'%3e%3c/polyline%3e%3c/svg%3e");
    background-repeat: no-repeat;
    background-position: right 0.5rem center;
    background-size: 1em;
}

.select-input:focus {
    border-color: var(--primary);
}

/* Results */
.results-section {
    flex: 1;
    display: flex;
    flex-direction: column;
    background: var(--bg-base);
    overflow: hidden;
}

.tabs {
    display: flex;
    border-bottom: 1px solid var(--border);
    background: var(--bg-surface);
}

.tab-btn {
    padding: 1rem 1.5rem;
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-family: inherit;
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    border-bottom: 2px solid transparent;
    transition: var(--transition);
}

.tab-btn:hover {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.02);
}

.tab-btn.active {
    color: var(--primary);
    border-bottom-color: var(--primary);
}

.tab-content {
    flex: 1;
    overflow: hidden;
    position: relative;
}

.view-panel {
    position: absolute;
    inset: 0;
    overflow: auto;
    padding: 2rem;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.2s;
}

.view-panel.active {
    opacity: 1;
    pointer-events: auto;
    z-index: 10;
}

.diff-wrapper {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.875rem;
    line-height: 1.6;
    white-space: pre-wrap;
    word-break: break-all;
}

.empty-state {
    color: var(--text-secondary);
    text-align: center;
    margin-top: 2rem;
    font-style: italic;
}

/* Diff highlights */
.diff-added {
    background-color: var(--diff-add-bg);
    color: var(--diff-add-text);
    text-decoration: none;
    border-radius: 3px;
    padding: 0.1em;
}

.diff-removed {
    background-color: var(--diff-sub-bg);
    color: var(--diff-sub-text);
    text-decoration: line-through;
    opacity: 0.8;
    border-radius: 3px;
    padding: 0.1em;
}

/* Markdown specific */
.markdown-body {
    font-family: 'Inter', sans-serif;
    line-height: 1.6;
}

.markdown-body h1, .markdown-body h2, .markdown-body h3 {
    margin-top: 1.5em;
    margin-bottom: 0.5em;
    color: var(--text-primary);
}

.markdown-body code {
    background: var(--bg-elevated);
    padding: 0.2em 0.4em;
    border-radius: 4px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.85em;
}

.markdown-body pre code {
    display: block;
    padding: 1rem;
    overflow-x: auto;
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(4px);
    z-index: 100;
    justify-content: center;
    align-items: center;
}

.modal.show {
    display: flex;
}

.modal-content {
    background: var(--bg-surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    width: 90%;
    max-width: 500px;
    max-height: 80vh;
    display: flex;
    flex-direction: column;
    box-shadow: var(--shadow);
}

.modal-header {
    padding: 1.5rem;
    border-bottom: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.close-modal {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-size: 1.5rem;
    cursor: pointer;
}

.modal-body {
    padding: 1.5rem;
    overflow-y: auto;
}

.history-list {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.history-item {
    padding: 1rem;
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    border-radius: 8px;
    cursor: pointer;
    transition: var(--transition);
}

.history-item:hover {
    border-color: var(--primary);
}

.history-meta {
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-bottom: 0.25rem;
    display: flex;
    justify-content: space-between;
}

.history-title {
    font-size: 0.875rem;
    font-weight: 500;
}

/* Toast */
.toast {
    position: fixed;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--primary);
    color: white;
    padding: 0.75rem 1.5rem;
    border-radius: 999px;
    font-size: 0.875rem;
    font-weight: 500;
    opacity: 0;
    transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    z-index: 1000;
    box-shadow: var(--shadow);
}

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