:root {
    --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --bg: #f9fafb;
    --bg-card: #ffffff;
    --bg-input: #ffffff;
    --bg-hover: #f3f4f6;
    --bg-muted: #f3f4f6;
    --text: #111827;
    --text-secondary: #4b5563;
    --text-muted: #9ca3af;
    --border: #e5e7eb;
    --border-focus: #6366f1;
    --accent: #6366f1;
    --accent-hover: #4f46e5;
    --accent-bg: #eef2ff;
    --accent-text: #4338ca;
    --success: #10b981;
    --success-bg: #ecfdf5;
    --success-text: #065f46;
    --warning: #f59e0b;
    --warning-bg: #fffbeb;
    --warning-text: #92400e;
    --danger: #ef4444;
    --danger-bg: #fef2f2;
    --danger-text: #991b1b;
    --radius: 12px;
    --radius-sm: 8px;
    --radius-xs: 6px;
    --shadow: 0 1px 3px rgba(0,0,0,0.08), 0 1px 2px rgba(0,0,0,0.04);
    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.08), 0 2px 4px -2px rgba(0,0,0,0.04);
    --shadow-lg: 0 10px 25px -5px rgba(0,0,0,0.1), 0 8px 10px -6px rgba(0,0,0,0.04);
    --transition: 0.15s ease;
}

[data-theme="dark"] {
    --bg: #0f1117;
    --bg-card: #1a1d27;
    --bg-input: #1a1d27;
    --bg-hover: #252833;
    --bg-muted: #252833;
    --text: #f3f4f6;
    --text-secondary: #d1d5db;
    --text-muted: #6b7280;
    --border: #2d3140;
    --border-focus: #818cf8;
    --accent: #818cf8;
    --accent-hover: #6366f1;
    --accent-bg: #1e1b4b;
    --accent-text: #c7d2fe;
    --success: #34d399;
    --success-bg: #064e3b;
    --success-text: #a7f3d0;
    --warning-bg: #451a03;
    --warning-text: #fde68a;
    --danger-bg: #450a0a;
    --danger-text: #fca5a5;
    --shadow: 0 1px 3px rgba(0,0,0,0.3);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.4);
    --shadow-lg: 0 10px 25px rgba(0,0,0,0.5);
}

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

body {
    font-family: var(--font);
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    min-height: 100vh;
    transition: background var(--transition), color var(--transition);
    -webkit-font-smoothing: antialiased;
}

/* Header */
.header {
    background: var(--bg-card);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow);
}

.header-inner {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0.8rem 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.brand {
    display: flex;
    align-items: center;
    gap: 0.6rem;
}

.brand-icon {
    width: 36px;
    height: 36px;
    background: var(--accent);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
}

.brand h1 {
    font-size: 1.25rem;
    font-weight: 700;
    letter-spacing: -0.02em;
}

.accent { color: var(--accent); }

.icon-btn {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    border: 1px solid var(--border);
    background: var(--bg-card);
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all var(--transition);
}

.icon-btn:hover {
    border-color: var(--accent);
    color: var(--accent);
    background: var(--accent-bg);
}

[data-theme="dark"] .icon-sun { display: block; }
[data-theme="dark"] .icon-moon { display: none; }
.icon-sun { display: none; }
.icon-moon { display: block; }

/* Main */
.main {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1.5rem;
}

/* Controls Bar */
.controls-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    margin-bottom: 1rem;
    flex-wrap: wrap;
}

.intensity-control {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.intensity-control label {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-secondary);
}

.intensity-tabs {
    display: flex;
    background: var(--bg-muted);
    border-radius: var(--radius-sm);
    padding: 3px;
    border: 1px solid var(--border);
}

.intensity-tab {
    padding: 0.4rem 0.9rem;
    font-size: 0.8rem;
    font-weight: 600;
    border: none;
    background: transparent;
    color: var(--text-muted);
    border-radius: var(--radius-xs);
    cursor: pointer;
    transition: all var(--transition);
}

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

.intensity-tab.active {
    background: var(--bg-card);
    color: var(--accent);
    box-shadow: var(--shadow);
}

.action-buttons {
    display: flex;
    gap: 0.5rem;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.55rem 1.1rem;
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    font-weight: 600;
    border: none;
    cursor: pointer;
    transition: all var(--transition);
    font-family: var(--font);
}

.btn:disabled { opacity: 0.5; cursor: not-allowed; }

.btn-primary {
    background: var(--accent);
    color: #fff;
    box-shadow: 0 1px 2px rgba(99, 102, 241, 0.3);
}

.btn-primary:hover:not(:disabled) {
    background: var(--accent-hover);
    transform: translateY(-1px);
    box-shadow: 0 4px 8px rgba(99, 102, 241, 0.3);
}

.btn-outline {
    background: var(--bg-card);
    color: var(--text);
    border: 1px solid var(--border);
}

.btn-outline:hover:not(:disabled) {
    border-color: var(--accent);
    color: var(--accent);
    background: var(--accent-bg);
}

.text-btn {
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 0.8rem;
    font-weight: 500;
    cursor: pointer;
    padding: 0.2rem 0.5rem;
    border-radius: var(--radius-xs);
    transition: all var(--transition);
    font-family: var(--font);
}

.text-btn:hover { color: var(--accent); background: var(--accent-bg); }

/* Editor Container */
.editor-container {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    gap: 0;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: var(--shadow-md);
    overflow: hidden;
    min-height: 480px;
}

.editor-wrapper {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    position: relative;
}

.editor-wrapper .tox-tinymce {
    border: none !important;
    border-radius: 0 !important;
    flex: 1;
}

.html-code-view {
    flex: 1;
    display: flex;
    flex-direction: column;
    padding: 0.75rem;
    gap: 0.5rem;
}

.html-textarea {
    flex: 1;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 0.75rem;
    font-family: 'Courier New', Consolas, monospace;
    font-size: 0.82rem;
    line-height: 1.6;
    resize: none;
    background: var(--bg);
    color: var(--text);
    outline: none;
}

.html-textarea:focus {
    border-color: var(--accent);
}

.btn-sm {
    padding: 0.35rem 0.7rem;
    font-size: 0.78rem;
}

.text-btn.active {
    color: var(--accent);
    background: var(--accent-bg);
}

.editor-panel {
    display: flex;
    flex-direction: column;
}

.panel-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.75rem 1rem;
    border-bottom: 1px solid var(--border);
    min-height: 44px;
}

.panel-title {
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.04em;
}

.panel-meta {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.word-count {
    font-size: 0.75rem;
    color: var(--text-muted);
    font-weight: 500;
}

.output-editor-wrap {
    flex: 1;
    position: relative;
    min-height: 380px;
}

.output-placeholder {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    position: absolute;
    inset: 0;
    z-index: 5;
    background: var(--bg-card);
    color: var(--text-muted);
    gap: 0.75rem;
}

.output-placeholder p {
    font-size: 0.9rem;
}

#outputEditorContainer {
    height: 100%;
    width: 100%;
}

#outputEditorContainer .tox-tinymce {
    border: none !important;
    border-radius: 0 !important;
}

#inputEditorWrap .tox-tinymce {
    border: none !important;
    border-radius: 0 !important;
}

.editor-divider {
    width: 1px;
    background: var(--border);
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
}

.divider-arrow {
    position: absolute;
    width: 28px;
    height: 28px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-muted);
}

/* Panel Footer / Score Badges */
.panel-footer {
    padding: 0.75rem 1rem;
    border-top: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.75rem;
}

.score-badge {
    display: flex;
    align-items: center;
    gap: 0.6rem;
}

.score-ring {
    position: relative;
    width: 36px;
    height: 36px;
}

.score-ring svg {
    width: 36px;
    height: 36px;
    transform: rotate(-90deg);
}

.ring-bg {
    fill: none;
    stroke: var(--bg-muted);
    stroke-width: 3;
}

.ring-fill {
    fill: none;
    stroke: var(--accent);
    stroke-width: 3;
    stroke-linecap: round;
    stroke-dasharray: 100.53;
    stroke-dashoffset: 100.53;
    transition: stroke-dashoffset 1s cubic-bezier(0.4, 0, 0.2, 1);
}

.ring-fill.success {
    stroke: var(--success);
}

.ring-fill.warning {
    stroke: var(--warning);
}

.ring-fill.danger {
    stroke: var(--danger);
}

.ring-value {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 0.6rem;
    font-weight: 700;
    color: var(--text);
}

.score-info {
    display: flex;
    flex-direction: column;
}

.score-title {
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--text);
}

.score-subtitle {
    font-size: 0.7rem;
    color: var(--text-muted);
}

.improvement-pill {
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
    padding: 0.3rem 0.6rem;
    background: var(--success-bg);
    color: var(--success-text);
    border-radius: 99px;
    font-size: 0.78rem;
    font-weight: 700;
}

/* Breakdown Section */
.breakdown-section {
    margin-top: 1.5rem;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.25rem;
    box-shadow: var(--shadow);
}

.breakdown-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 1rem;
}

.breakdown-header h3 {
    font-size: 0.95rem;
    font-weight: 700;
}

.breakdown-tabs {
    display: flex;
    background: var(--bg-muted);
    border-radius: var(--radius-xs);
    padding: 2px;
}

.breakdown-tab {
    padding: 0.3rem 0.75rem;
    font-size: 0.75rem;
    font-weight: 600;
    border: none;
    background: transparent;
    color: var(--text-muted);
    border-radius: 4px;
    cursor: pointer;
    transition: all var(--transition);
    font-family: var(--font);
}

.breakdown-tab.active {
    background: var(--bg-card);
    color: var(--text);
    box-shadow: var(--shadow);
}

.breakdown-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 0.6rem;
}

.breakdown-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.6rem 0.8rem;
    background: var(--bg-muted);
    border-radius: var(--radius-xs);
    transition: all var(--transition);
}

.breakdown-item:hover {
    background: var(--bg-hover);
}

.factor-name {
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--text-secondary);
    flex: 1;
    white-space: nowrap;
}

.factor-bar-container {
    flex: 1.2;
    height: 5px;
    background: var(--border);
    border-radius: 3px;
    overflow: hidden;
}

.factor-bar-fill {
    height: 100%;
    border-radius: 3px;
    transition: width 0.8s cubic-bezier(0.4, 0, 0.2, 1);
}

.factor-bar-fill.low { background: var(--success); }
.factor-bar-fill.medium { background: var(--warning); }
.factor-bar-fill.high { background: var(--danger); }

.factor-score {
    font-size: 0.75rem;
    font-weight: 700;
    min-width: 32px;
    text-align: right;
}

.factor-score.low { color: var(--success); }
.factor-score.medium { color: var(--warning); }
.factor-score.high { color: var(--danger); }

/* Flags */
.flags-section {
    margin-top: 1rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border);
}

.flags-section h4 {
    font-size: 0.82rem;
    font-weight: 600;
    margin-bottom: 0.6rem;
    color: var(--text-secondary);
}

.flags-list {
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
}

.flag-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 0.75rem;
    border-radius: var(--radius-xs);
    font-size: 0.8rem;
}

.flag-item.high { background: var(--danger-bg); color: var(--danger-text); }
.flag-item.medium { background: var(--warning-bg); color: var(--warning-text); }
.flag-item.low { background: var(--accent-bg); color: var(--accent-text); }

.flag-dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    flex-shrink: 0;
}

.flag-item.high .flag-dot { background: var(--danger); }
.flag-item.medium .flag-dot { background: var(--warning); }
.flag-item.low .flag-dot { background: var(--accent); }

/* Stats Bar */
.stats-bar {
    margin-top: 1rem;
    display: flex;
    gap: 1.5rem;
    padding: 0.75rem 1rem;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    box-shadow: var(--shadow);
}

.stat-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.stat-label {
    font-size: 0.78rem;
    color: var(--text-muted);
}

.stat-value {
    font-size: 0.82rem;
    font-weight: 700;
    color: var(--text);
}

/* API Notice */
.api-notice {
    margin-top: 1rem;
    display: flex;
    align-items: center;
    gap: 0.6rem;
    padding: 0.7rem 1rem;
    background: var(--warning-bg);
    color: var(--warning-text);
    border-radius: var(--radius-sm);
    font-size: 0.82rem;
    border: 1px solid var(--warning);
}

.api-notice.success {
    background: var(--success-bg);
    color: var(--success-text);
    border-color: var(--success);
}

/* Loading */
.loading-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.4);
    backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
}

.loading-card {
    background: var(--bg-card);
    border-radius: var(--radius);
    padding: 2rem 3rem;
    text-align: center;
    box-shadow: var(--shadow-lg);
}

.loading-spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--border);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 0.7s linear infinite;
    margin: 0 auto 1rem;
}

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

.loading-text {
    font-weight: 600;
    font-size: 0.95rem;
    color: var(--text);
}

.loading-sub {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-top: 0.3rem;
}

/* Footer */
.footer {
    text-align: center;
    padding: 1.5rem;
    color: var(--text-muted);
    font-size: 0.8rem;
}

/* Responsive */
@media (max-width: 768px) {
    .editor-container {
        grid-template-columns: 1fr;
        min-height: auto;
    }

    .editor-divider {
        width: 100%;
        height: 1px;
    }

    .divider-arrow {
        transform: rotate(90deg);
    }

    .editor-textarea,
    .editor-output {
        min-height: 200px;
    }

    .controls-bar {
        flex-direction: column;
        align-items: stretch;
    }

    .intensity-control {
        justify-content: center;
    }

    .action-buttons {
        justify-content: center;
    }

    .breakdown-grid {
        grid-template-columns: 1fr;
    }

    .stats-bar {
        flex-wrap: wrap;
        gap: 0.75rem;
    }

    .main {
        padding: 1rem;
    }
}

/* Animations */
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
}

.fade-in-up {
    animation: fadeInUp 0.3s ease-out;
}

/* Toast Notification */
.toast {
    position: fixed;
    top: 1rem;
    right: 1rem;
    padding: 0.75rem 1.25rem;
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    font-weight: 500;
    z-index: 2000;
    animation: fadeInUp 0.3s ease-out;
    box-shadow: var(--shadow-lg);
}

.toast.error { background: var(--danger-bg); color: var(--danger-text); border: 1px solid var(--danger); }
.toast.warning { background: var(--warning-bg); color: var(--warning-text); border: 1px solid var(--warning); }
.toast.success { background: var(--success-bg); color: var(--success-text); border: 1px solid var(--success); }

/* Scrollbar */
.editor-output::-webkit-scrollbar,
.editor-textarea::-webkit-scrollbar {
    width: 6px;
}

.editor-output::-webkit-scrollbar-track,
.editor-textarea::-webkit-scrollbar-track {
    background: transparent;
}

.editor-output::-webkit-scrollbar-thumb,
.editor-textarea::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 3px;
}

.editor-output::-webkit-scrollbar-thumb:hover,
.editor-textarea::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}