:root {
    --gct-bg-main: #f8fafc;
    --gct-bg-card: #ffffff;
    --gct-border: #e2e8f0;
    --gct-text: #0f172a;
    --gct-text-muted: #64748b;
    --gct-accent-gradient: linear-gradient(135deg, #4f46e5 0%, #7c3aed 100%);
    --gct-danger-alpha: #fee2e2;
    --gct-danger-text: #b91c1c;
    --gct-warning-alpha: #fef3c7;
    --gct-warning-text: #b45309;
}

.gct-dark-theme {
    --gct-bg-main: #0f172a;
    --gct-bg-card: #1e293b;
    --gct-border: #334155;
    --gct-text: #f8fafc;
    --gct-text-muted: #94a3b8;
    --gct-danger-alpha: #451a1a;
    --gct-danger-text: #fca5a5;
    --gct-warning-alpha: #453216;
    --gct-warning-text: #fde68a;
}

#gct-container {
    background: var(--gct-bg-main);
    color: var(--gct-text);
    border: 1px solid var(--gct-border);
    border-radius: 12px;
    padding: 24px;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-sizing: border-box;
}

#gct-container * { box-sizing: border-box; }

.gct-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 2px solid var(--gct-border);
    padding-bottom: 16px;
    margin-bottom: 20px;
}

.gct-header h2 {
    margin: 0;
    font-size: 22px;
    font-weight: 700;
    background: var(--gct-accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.gct-workspace {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 24px;
}

@media(max-width: 960px) {
    .gct-workspace { grid-template-columns: 1fr; }
}

.gct-main-panel {
    background: var(--gct-bg-card);
    border: 1px solid var(--gct-border);
    border-radius: 8px;
    display: flex;
    flex-direction: column;
}

.gct-toolbar {
    background: var(--gct-bg-main);
    padding: 10px;
    border-bottom: 1px solid var(--gct-border);
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 8px;
}

.gct-btn-action, .gct-upload-label {
    background: var(--gct-bg-card);
    border: 1px solid var(--gct-border);
    color: var(--gct-text);
    padding: 6px 12px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 13px;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

.gct-btn-danger {
    background: var(--gct-danger-alpha);
    border: 1px solid transparent;
    color: var(--gct-danger-text);
    padding: 6px 12px;
    border-radius: 6px;
    cursor: pointer;
}

.gct-editor-wrapper {
    position: relative;
    flex-grow: 1;
    min-height: 350px;
}

#gct-editor {
    width: 100%;
    height: 100%;
    min-height: 350px;
    border: none;
    resize: vertical;
    padding: 16px;
    font-size: 16px;
    line-height: 1.6;
    background: transparent;
    color: var(--gct-text);
    outline: none;
}

.gct-editor-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 16px;
    background: var(--gct-bg-main);
    border-top: 1px solid var(--gct-border);
}

.gct-live-stats {
    color: var(--gct-text-muted);
    font-size: 13px;
}

.gct-btn-gradient {
    background: var(--gct-accent-gradient);
    color: #ffffff;
    border: none;
    padding: 10px 20px;
    border-radius: 6px;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s;
}

.gct-btn-gradient:hover { transform: translateY(-1px); }

/* Sidebar Tabs Setup */
.gct-sidebar {
    background: var(--gct-bg-card);
    border: 1px solid var(--gct-border);
    border-radius: 8px;
    padding: 16px;
}

.gct-tabs {
    display: flex;
    border-bottom: 1px solid var(--gct-border);
    margin-bottom: 16px;
    gap: 4px;
}

.gct-tab-btn {
    background: transparent;
    border: none;
    color: var(--gct-text-muted);
    padding: 8px 12px;
    cursor: pointer;
    font-size: 13px;
    border-bottom: 2px solid transparent;
}

.gct-tab-btn.active {
    color: var(--gct-text);
    border-bottom-color: #4f46e5;
    font-weight: 600;
}

.gct-tab-content { display: none; }
.gct-tab-content.active { display: block; }

/* Correction Cards */
.gct-suggestion-card {
    background: var(--gct-bg-main);
    border-left: 4px solid #ef4444;
    padding: 12px;
    border-radius: 4px;
    margin-bottom: 12px;
    animation: fadeSlideIn 0.3s ease;
}

.gct-suggestion-card.grammar-issue { border-left-color: #3b82f6; }
.gct-suggestion-card.style-issue { border-left-color: #eab308; }

.gct-card-header {
    font-weight: 600;
    font-size: 12px;
    text-transform: uppercase;
    color: var(--gct-text-muted);
    margin-bottom: 6px;
}

.gct-error-context {
    font-size: 14px;
    margin-bottom: 8px;
}

.gct-replacement-pill {
    display: inline-block;
    background: var(--gct-accent-gradient);
    color: white;
    padding: 4px 10px;
    border-radius: 4px;
    font-size: 13px;
    cursor: pointer;
    margin-right: 6px;
    font-weight: 500;
}

/* AI & Metrics Layouts */
.gct-ai-options select {
    width: 100%;
    padding: 8px;
    background: var(--gct-bg-main);
    color: var(--gct-text);
    border: 1px solid var(--gct-border);
    border-radius: 4px;
    margin: 8px 0 12px;
}

.gct-btn-ai-submit {
    width: 100%;
    background: #10b981;
    color: white;
    border: none;
    padding: 10px;
    border-radius: 6px;
    cursor: pointer;
}

.gct-ai-output-box {
    margin-top: 12px;
    background: var(--gct-bg-main);
    padding: 12px;
    border-radius: 6px;
    min-height: 100px;
    white-space: pre-wrap;
    font-size: 14px;
}

.gct-dashboard-metrics {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 10px;
    margin-bottom: 16px;
}

.grid-span-2 { grid-column: span 2; }

.gct-metric-card {
    background: var(--gct-bg-main);
    padding: 12px;
    border-radius: 6px;
    text-align: center;
}

.gct-metric-label {
    display: block;
    font-size: 11px;
    color: var(--gct-text-muted);
    text-transform: uppercase;
}

.gct-metric-val {
    font-size: 18px;
    font-weight: 700;
}

.gct-global-actions-bar {
    display: flex;
    justify-content: flex-end;
    gap: 10px;
    margin-top: 16px;
}

.gct-btn-utility {
    background: var(--gct-bg-card);
    border: 1px solid var(--gct-border);
    color: var(--gct-text);
    padding: 8px 16px;
    border-radius: 6px;
    cursor: pointer;
}

.gct-keyword-pill {
    display: flex;
    justify-content: space-between;
    padding: 6px;
    background: var(--gct-bg-main);
    margin-bottom: 4px;
    border-radius: 4px;
    font-size: 13px;
}

.gct-empty-state {
    text-align: center;
    color: var(--gct-text-muted);
    padding: 40px 10px;
}

.gct-empty-state i {
    font-size: 36px;
    margin-bottom: 12px;
    opacity: 0.5;
}

@keyframes fadeSlideIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}