:root {
    --bg-base: #09090b;
    --bg-surface: #18181b;
    --bg-element: #27272a;
    --text-heading: #fafafa;
    --text-body: #a1a1aa;
    --accent-glow: #6366f1;
    --accent-gradient: linear-gradient(135deg, #6366f1 0%, #a855f7 100%);
    --status-success: #10b981;
    --border-subtle: #3f3f46;
    --radius-main: 14px;
    --transition-smooth: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: 'Plus Jakarta Sans', sans-serif;
    background-color: var(--bg-base);
    color: var(--text-body);
    line-height: 1.6;
    padding: 60px 24px;
}

.app-wrapper {
    max-width: 900px;
    margin: 0 auto;
}

/* Screen reader utility for crawler navigation without cluttering visuals */
.visual-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    border: 0;
}

/* App Branding Header */
header {
    text-align: center;
    margin-bottom: 48px;
}

header h1 {
    color: var(--text-heading);
    font-size: 2.75rem;
    font-weight: 700;
    letter-spacing: -0.04em;
    margin-bottom: 12px;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

header p {
    font-size: 1.1rem;
    font-weight: 500;
}

/* Tool Canvas Component */
.workspace-card {
    background-color: var(--bg-surface);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-main);
    padding: 40px;
    box-shadow: 0 20px 40px -15px rgba(0,0,0,0.5);
    margin-bottom: 64px;
}

/* Drag & Drop Canvas Area */
.drop-target {
    border: 2px dashed var(--border-subtle);
    border-radius: var(--radius-main);
    padding: 56px 24px;
    text-align: center;
    cursor: pointer;
    transition: var(--transition-smooth);
    background-color: rgba(24, 24, 27, 0.5);
}

.drop-target:hover {
    border-color: var(--accent-glow);
    background-color: rgba(99, 102, 241, 0.04);
}

.drop-target svg {
    color: var(--text-body);
    margin-bottom: 16px;
    transition: var(--transition-smooth);
}

.drop-target:hover svg {
    color: var(--accent-glow);
    transform: translateY(-4px);
}

.drop-target p span {
    color: var(--text-heading);
    font-weight: 600;
    text-decoration: underline;
}

/* Split-Screen Interactive Workspace */
.editor-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 32px;
    margin-top: 40px;
}

@media (max-width: 768px) {
    .editor-grid { grid-template-columns: 1fr; }
}

.display-panel {
    background-color: var(--bg-element);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-main);
    padding: 20px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.display-panel img {
    max-width: 100%;
    max-height: 240px;
    object-fit: contain;
    border-radius: 8px;
    margin-bottom: 16px;
}

.meta-data {
    width: 100%;
    font-size: 0.85rem;
    display: flex;
    justify-content: space-between;
    color: var(--text-heading);
}

/* Control Panel Optimization Framework */
.dashboard {
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 28px;
}

.tabs-selector {
    display: flex;
    background-color: var(--bg-base);
    padding: 4px;
    border-radius: 8px;
    border: 1px solid var(--border-subtle);
}

.tab-btn {
    flex: 1;
    background: none;
    border: none;
    color: var(--text-body);
    padding: 8px;
    font-family: inherit;
    font-weight: 600;
    cursor: pointer;
    border-radius: 6px;
    transition: var(--transition-smooth);
}

.tab-btn.active {
    background-color: var(--bg-element);
    color: var(--text-heading);
}

.control-block {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.control-block label {
    color: var(--text-heading);
    font-weight: 600;
    font-size: 0.95rem;
}

/* Dynamic Form Inputs */
input[type="number"] {
    background-color: var(--bg-base);
    border: 1px solid var(--border-subtle);
    padding: 12px;
    border-radius: 8px;
    color: var(--text-heading);
    font-family: inherit;
    font-size: 1rem;
    outline: none;
}

input[type="number"]:focus {
    border-color: var(--accent-glow);
}

input[type="range"] {
    -webkit-appearance: none;
    width: 100%;
    height: 6px;
    background: var(--bg-base);
    border-radius: 3px;
    outline: none;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--accent-glow);
    cursor: pointer;
}

/* Performance Execution UI Actions */
.action-trigger {
    background: var(--accent-gradient);
    color: var(--text-heading);
    font-family: inherit;
    font-weight: 700;
    font-size: 1rem;
    padding: 14px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: var(--transition-smooth);
}

.action-trigger:hover {
    opacity: 0.9;
    transform: scale(0.99);
}

/* Output Metrics Panel */
.status-panel {
    margin-top: 32px;
    padding: 24px;
    background-color: rgba(16, 185, 129, 0.05);
    border: 1px solid var(--status-success);
    border-radius: var(--radius-main);
    text-align: center;
}

.status-panel h3 {
    color: var(--status-success);
    margin-bottom: 6px;
}

.download-btn {
    display: inline-block;
    margin-top: 14px;
    background-color: var(--status-success);
    color: var(--text-heading);
    padding: 12px 28px;
    border-radius: 8px;
    font-weight: 600;
    text-decoration: none;
    transition: var(--transition-smooth);
}

/* SEO Keyword Grid Copy Section */
.seo-grid-section {
    border-top: 1px solid var(--border-subtle);
    padding-top: 64px;
}

.seo-grid-section h2 {
    color: var(--text-heading);
    font-size: 2rem;
    margin-bottom: 16px;
    letter-spacing: -0.03em;
}

.seo-grid-section > p {
    margin-bottom: 40px;
    font-size: 1.05rem;
}

.matrix-box {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 24px;
}

.matrix-card {
    background-color: var(--bg-surface);
    border: 1px solid var(--border-subtle);
    padding: 28px;
    border-radius: var(--radius-main);
}

.matrix-card h3 {
    color: var(--text-heading);
    font-size: 1.15rem;
    margin-bottom: 12px;
}

/* FAQ Styling */
.seo-faq-section {
    margin-top: 56px;
    border-top: 1px solid var(--border-subtle);
    padding-top: 48px;
}

.seo-faq-section h2 {
    color: var(--text-heading);
    font-size: 1.75rem;
    margin-bottom: 24px;
}

.faq-item {
    margin-bottom: 24px;
}

.faq-item h3 {
    color: var(--text-heading);
    font-size: 1.1rem;
    margin-bottom: 8px;
}