:root {
    /* Soft Midnight Palette (Inspired by Reference) */
    --bg-base: #0d1117;
    --bg-main: var(--bg-base);
    --bg-surface: #161b22;
    --bg-elevated: #21262d;
    --border-subtle: #21262d;
    --border-strong: #30363d;

    --text-primary: #f0f6fc;
    --text-secondary: #8b949e;
    --text-placeholder: #484f58;
    --text-on-color: #ffffff;

    --brand-primary: #2ccb7d;
    --brand-primary-hover: #23a364;
    --brand-active: #1a7a4a;

    --status-error: #f85149;
    --status-error-bg: #211515;
    --status-success: #2ccb7d;
    --status-success-bg: #15211b;
    --status-warning: #d29922;

    --focus-ring: 0 0 0 2px var(--bg-base), 0 0 0 4px var(--brand-primary);

    /* Typography */
    --font-mono: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
    --font-sans: var(--font-mono);

    /* Metrics & Spacing (Softer Corners) */
    --sidebar-width: 260px;
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --transition-fast: 0.15s cubic-bezier(0.2, 0, 0.38, 0.9);
}

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

body {
    font-family: var(--font-sans);
    background-color: var(--bg-base);
    color: var(--text-primary);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
    height: 100vh;
    overflow: hidden;
}

h1,
h2,
h3,
h4 {
    font-weight: 600;
}

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

/* Sidebar Navigation */
.sidebar {
    width: var(--sidebar-width);
    background-color: var(--bg-surface);
    border-right: 1px solid var(--border-subtle);
    display: flex;
    flex-direction: column;
    flex-shrink: 0;
}

.sidebar-header {
    padding: var(--spacing-xl) var(--spacing-lg);
    border-bottom: 1px solid var(--border-subtle);
}

.sidebar-header h2 {
    font-size: 1.25rem;
    letter-spacing: -0.02em;
}

.highlight {
    color: var(--brand-primary);
}

.sidebar-nav {
    display: flex;
    flex-direction: column;
    padding: var(--spacing-md) 0;
    overflow-y: auto;
}

.nav-category {
    padding: var(--spacing-md) var(--spacing-lg) var(--spacing-xs);
    font-size: 0.65rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1.2px;
    color: var(--text-placeholder);
    pointer-events: none;
    user-select: none;
}


.nav-item {
    display: flex;
    align-items: center;
    padding: var(--spacing-sm) var(--spacing-lg);
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-size: 0.875rem;
    font-family: var(--font-sans);
    font-weight: 500;
    text-align: left;
    cursor: pointer;
    transition: background-color var(--transition-fast), color var(--transition-fast);
    position: relative;
    gap: var(--spacing-sm);
}

.nav-item svg {
    width: 18px;
    height: 18px;
    opacity: 0.7;
    transition: opacity var(--transition-fast);
}

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

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

.nav-item.active::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 3px;
    background-color: var(--brand-primary);
}

.nav-item.active svg {
    opacity: 1;
    color: var(--brand-primary);
}

.nav-item:focus-visible {
    outline: none;
    box-shadow: inset 0 0 0 2px var(--brand-primary);
}

/* Main Content Area */
.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    min-width: 0;
    /* Important for deeply nested flex/grids */
}

.top-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md) var(--spacing-xl);
    border-bottom: 1px solid var(--border-subtle);
    background-color: var(--bg-base);
    min-height: 64px;
}

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

.top-actions {
    display: flex;
    gap: var(--spacing-sm);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-sm) var(--spacing-md);
    font-family: var(--font-sans);
    font-size: 0.875rem;
    font-weight: 500;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all var(--transition-fast);
    border: 1px solid transparent;
    gap: 0.5rem;
}

.btn:focus-visible {
    outline: none;
    box-shadow: var(--focus-ring);
}

.btn-primary {
    background-color: var(--brand-primary);
    color: var(--text-on-color);
}

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

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

.btn-secondary:hover {
    background-color: var(--border-strong);
}

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

/* Inputs & Textareas */
.input-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-md);
}

.input-label {
    font-size: 0.75rem;
    color: var(--text-secondary);
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

input[type="text"],
input[type="number"],
textarea {
    width: 100%;
    background-color: var(--bg-surface);
    border: 1px solid var(--border-strong);
    color: var(--text-primary);
    border-radius: var(--radius-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    font-family: var(--font-mono);
    font-size: 0.875rem;
    transition: border-color var(--transition-fast);
}

textarea {
    resize: none;
}

input:focus,
textarea:focus {
    outline: none;
    border-color: var(--brand-primary);
}

input::placeholder,
textarea::placeholder {
    color: var(--text-placeholder);
}

/* File Upload Area */
.file-upload-area {
    border: 2px dashed var(--border-strong);
    border-radius: var(--radius-md);
    padding: var(--spacing-xl);
    text-align: center;
    cursor: pointer;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
    background-color: var(--bg-surface);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
}

.file-upload-area:hover,
.file-upload-area.dragover {
    border-color: var(--brand-primary);
    background-color: var(--bg-elevated);
    color: var(--text-primary);
}

.file-upload-area svg {
    width: 32px;
    height: 32px;
    color: var(--text-placeholder);
}

/* Workspace Container */
.workspace {
    flex: 1;
    padding: var(--spacing-xl);
    overflow-y: auto;
    display: flex;
    flex-direction: column;
}

/* Tool Layouts */
.tool-grid-2 {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-lg);
    flex: 1;
    min-height: 0;
}

.pane {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
    height: 100%;
}

.pane-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    min-height: 32px;
}

.editor-container {
    flex: 1;
    position: relative;
    border: 1px solid var(--border-strong);
    border-radius: var(--radius-md);
    overflow: hidden;
    background-color: var(--bg-surface);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

.editor-textarea {
    display: block;
    width: 100%;
    height: 100%;
    border: none;
    margin: 0;
    padding: var(--spacing-md);
    background: transparent;
    color: var(--text-primary);
    font-family: var(--font-mono);
    font-size: 0.875rem;
    line-height: 1.5;
    white-space: pre-wrap;
    word-break: break-all;
    overflow: auto;
    resize: none;
}

.editor-textarea:focus {
    outline: none;
    box-shadow: inset 0 0 0 1px var(--brand-primary);
}

/* Readonly Output Styling */
.output-display {
    padding: var(--spacing-md);
    font-family: var(--font-mono);
    font-size: 0.875rem;
    white-space: pre-wrap;
    word-break: break-all;
    background-color: var(--bg-base);
}

/* Validation Status */
.validation-message {
    font-size: 0.75rem;
    margin-top: var(--spacing-xs);
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

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

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

/* Toasts */
.toast-container {
    position: fixed;
    bottom: var(--spacing-xl);
    right: var(--spacing-xl);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
    z-index: 1000;
}

.toast {
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-sm);
    background-color: var(--bg-elevated);
    color: var(--text-primary);
    font-size: 0.875rem;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    animation: slideIn var(--transition-fast) forwards;
    border-left: 4px solid var(--brand-primary);
}

.toast.error {
    border-left-color: var(--status-error);
    background-color: var(--status-error-bg);
}

.toast.success {
    border-left-color: var(--status-success);
    background-color: var(--status-success-bg);
}

@keyframes slideIn {
    from {
        transform: translateX(100%);
        opacity: 0;
    }

    to {
        transform: translateX(0);
        opacity: 1;
    }
}

@keyframes slideOut {
    from {
        transform: translateX(0);
        opacity: 1;
    }

    to {
        transform: translateX(100%);
        opacity: 0;
    }
}

/* Diff Checker Specifics */
.diff-line {
    display: flex;
    font-family: var(--font-mono);
    font-size: 0.875rem;
    line-height: 1.5;
}

.diff-line.added {
    background-color: rgba(36, 161, 72, 0.15);
    color: #42be65;
}

.diff-line.removed {
    background-color: rgba(218, 30, 40, 0.15);
    color: #ff8389;
}

.diff-line-number {
    width: 40px;
    min-width: 40px;
    padding: 0 8px;
    color: var(--text-placeholder);
    text-align: right;
    user-select: none;
    border-right: 1px solid var(--border-strong);
    background-color: var(--bg-surface);
}

.diff-line-content {
    padding-left: var(--spacing-md);
    white-space: pre-wrap;
    word-break: break-all;
}

/* Loading Spinner */
.spinner {
    width: 20px;
    height: 20px;
    border: 2px solid var(--border-strong);
    border-top-color: var(--brand-primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

/* Command Palette (Spotlight Search) */
.command-palette-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(0, 0, 0, 0.75);
    backdrop-filter: blur(4px);
    z-index: 2000;
    display: none;
    /* Hidden by default */
    align-items: flex-start;
    justify-content: center;
    padding-top: 15vh;
}

.command-palette {
    width: 600px;
    max-width: 90%;
    background-color: var(--bg-surface);
    border: 1px solid var(--border-strong);
    border-radius: var(--radius-lg);
    box-shadow: 0 12px 48px rgba(0, 0, 0, 0.5);
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.command-search-input-wrapper {
    display: flex;
    align-items: center;
    padding: var(--spacing-md) var(--spacing-lg);
    border-bottom: 1px solid var(--border-subtle);
    gap: var(--spacing-md);
}

.command-search-input-wrapper svg {
    width: 20px;
    height: 20px;
    color: var(--text-placeholder);
}

.command-search-input {
    flex: 1;
    background: transparent;
    border: none;
    color: var(--text-primary);
    font-size: 1.125rem;
    font-family: var(--font-sans);
    outline: none;
}

.command-results {
    max-height: 400px;
    overflow-y: auto;
    padding: var(--spacing-xs) 0;
}

.command-result-item {
    display: flex;
    align-items: center;
    padding: var(--spacing-md) var(--spacing-lg);
    gap: var(--spacing-md);
    cursor: pointer;
    transition: background-color var(--transition-fast);
}

.command-result-item.active {
    background-color: var(--bg-elevated);
}

.command-result-item svg {
    width: 18px;
    height: 18px;
    color: var(--text-secondary);
}

.command-result-info {
    display: flex;
    flex-direction: column;
}

.command-result-title {
    font-size: 0.9375rem;
    font-weight: 500;
    color: var(--text-primary);
}

.command-result-description {
    font-size: 0.75rem;
    color: var(--text-placeholder);
}

.command-palette-footer {
    padding: var(--spacing-sm) var(--spacing-lg);
    background-color: var(--bg-base);
    border-top: 1px solid var(--border-subtle);
    display: flex;
    justify-content: flex-end;
    gap: var(--spacing-lg);
}

.command-hint {
    font-size: 0.6875rem;
    color: var(--text-placeholder);
    display: flex;
    align-items: center;
    gap: 4px;
}

.command-key {
    background-color: var(--bg-elevated);
    padding: 2px 6px;
    border-radius: 3px;
    border: 1px solid var(--border-strong);
    color: var(--text-secondary);
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 10px;
    height: 10px;
}

::-webkit-scrollbar-track {
    background: var(--bg-base);
}

::-webkit-scrollbar-thumb {
    background: var(--bg-elevated);
    border: 2px solid var(--bg-base);
    border-radius: 10px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--border-strong);
}

/* Firefox Scrollbar */
* {
    scrollbar-width: thin;
    scrollbar-color: var(--bg-elevated) var(--bg-base);
}

/* Pill Toggle / Segmented Control */
.pill-toggle {
    display: inline-flex;
    background: var(--bg-elevated);
    padding: 3px;
    border-radius: 20px;
    border: 1px solid var(--border-strong);
    gap: 4px;
}

.pill-option {
    padding: 5px 14px;
    border-radius: 17px;
    cursor: pointer;
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
    user-select: none;
}

.pill-option:hover {
    color: var(--text-primary);
}

.pill-option.active {
    background: var(--brand-primary);
    color: var(--text-on-color);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

/* Dashboard Styles */
.dashboard-container {
    max-width: 1000px;
    margin: 0 auto;
    width: 100%;
    animation: fadeIn 0.4s ease-out;
}

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

.dashboard-header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin: 0;
    background: linear-gradient(135deg, var(--brand-primary), #4ade80);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.dashboard-header p {
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin: var(--spacing-sm) 0 0 0;
}

.dashboard-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: var(--spacing-xl);
}

.dashboard-category {
    background: var(--bg-surface);
    border: 1px solid var(--border-strong);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
}

.category-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 0.9rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--brand-primary);
    margin-bottom: var(--spacing-lg);
    border-bottom: 1px solid var(--border-subtle);
    padding-bottom: var(--spacing-sm);
}

.category-header svg {
    width: 18px;
    height: 18px;
}

.tool-links {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.tool-card {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    background: var(--bg-elevated);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.tool-card:hover {
    border-color: var(--brand-primary);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
    background: #2a3038;
}

.tool-card-icon {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-surface);
    border-radius: var(--radius-sm);
    color: var(--brand-primary);
}

.tool-card-icon svg {
    width: 20px;
    height: 20px;
}

.tool-card-content h4 {
    margin: 0;
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
}

.tool-card-content p {
    margin: 4px 0 0 0;
    font-size: 0.8rem;
    color: var(--text-secondary);
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* JSON Syntax Highlighting */
.json-key {
    color: #7dd3fc;
}

.json-str {
    color: #a7f3d0;
}

.json-num {
    color: #fbbf24;
}

.json-bool {
    color: #f472b6;
}

.json-null {
    color: #94a3b8;
}