/* ============================================================
   Scalable Converters — Premium Design System
   Mobile-first • Dark Mode • Glassmorphism • Accessible
   ============================================================ */

/* Google Font */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&display=swap');

/* ── Design Tokens ─────────────────────────────────────── */
:root {
    /* Brand gradient */
    --gradient-start: #6366f1;
    --gradient-mid: #8b5cf6;
    --gradient-end: #a78bfa;

    /* Light theme */
    --primary: #6366f1;
    --primary-hover: #4f46e5;
    --primary-glow: rgba(99, 102, 241, 0.25);
    --bg-color: #f1f5f9;
    --bg-subtle: #e2e8f0;
    --surface-color: #ffffff;
    --surface-glass: rgba(255, 255, 255, 0.72);
    --text-main: #0f172a;
    --text-secondary: #334155;
    --text-muted: #64748b;
    --border-color: rgba(148, 163, 184, 0.35);
    --border-strong: #cbd5e1;
    --radius: 16px;
    --radius-sm: 10px;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
    --shadow-md: 0 4px 14px rgba(0,0,0,0.08), 0 2px 6px rgba(0,0,0,0.04);
    --shadow-lg: 0 10px 40px rgba(0,0,0,0.1), 0 2px 10px rgba(0,0,0,0.04);
    --shadow-glow: 0 0 30px var(--primary-glow);
    --transition-fast: 0.15s cubic-bezier(0.4, 0, 0.2, 1);
    --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ── Dark Mode ─────────────────────────────────────────── */
@media (prefers-color-scheme: dark) {
    :root {
        --primary: #818cf8;
        --primary-hover: #a5b4fc;
        --primary-glow: rgba(129, 140, 248, 0.2);
        --bg-color: #0f172a;
        --bg-subtle: #1e293b;
        --surface-color: #1e293b;
        --surface-glass: rgba(30, 41, 59, 0.78);
        --text-main: #f1f5f9;
        --text-secondary: #cbd5e1;
        --text-muted: #94a3b8;
        --border-color: rgba(100, 116, 139, 0.3);
        --border-strong: #334155;
        --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
        --shadow-md: 0 4px 14px rgba(0,0,0,0.35);
        --shadow-lg: 0 10px 40px rgba(0,0,0,0.45);
    }
}

/* ── Reset & Base ──────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-main);
    line-height: 1.65;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    transition: background-color var(--transition), color var(--transition);
}

/* RTL support for Urdu */
body.rtl { direction: rtl; text-align: right; }

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 1.25rem;
}

/* ── Animations ────────────────────────────────────────── */
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(18px); }
    to   { opacity: 1; transform: translateY(0); }
}
@keyframes shimmer {
    0%   { background-position: -200% center; }
    100% { background-position: 200% center; }
}
@keyframes pulseGlow {
    0%, 100% { box-shadow: 0 0 0 0 var(--primary-glow); }
    50%      { box-shadow: 0 0 20px 4px var(--primary-glow); }
}

.animate-in {
    animation: fadeInUp 0.5s var(--transition) both;
}

/* ── Header ────────────────────────────────────────────── */
.header {
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-mid), var(--gradient-end));
    padding: 2rem 0;
    position: relative;
    overflow: hidden;
}
.header::before {
    content: '';
    position: absolute; inset: 0;
    background: radial-gradient(circle at 20% 50%, rgba(255,255,255,0.12) 0%, transparent 50%),
                radial-gradient(circle at 80% 20%, rgba(255,255,255,0.08) 0%, transparent 40%);
    pointer-events: none;
}

.header-flex {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
    position: relative;
    z-index: 1;
}

.header h1 {
    font-size: 1.65rem;
    font-weight: 800;
    color: #fff;
    letter-spacing: -0.025em;
    text-shadow: 0 2px 8px rgba(0,0,0,0.15);
}

#language-select {
    padding: 0.5rem 0.75rem;
    border-radius: var(--radius-sm);
    border: 1px solid rgba(255,255,255,0.3);
    background: rgba(255,255,255,0.15);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    color: #fff;
    font-family: inherit;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition-fast);
}
#language-select:hover { background: rgba(255,255,255,0.25); }
#language-select option { color: var(--text-main); background: var(--surface-color); }

/* ── Featured Image ────────────────────────────────────── */

/* Main Navigation */
.main-nav {
    margin-top: 1.25rem;
}
.nav-container {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: flex-start;
    gap: 0.75rem;
}
.nav-link {
    color: #fff;
    text-decoration: none;
    font-weight: 600;
    padding: 0.45rem 0.9rem;
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.16);
    transition: var(--transition-fast);
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
}
.nav-link:hover,
.nav-link:focus-visible {
    background: rgba(255, 255, 255, 0.3);
}
.nav-dropdown {
    position: relative;
}
.nav-dropdown summary {
    list-style: none;
    cursor: pointer;
}
.nav-dropdown summary::-webkit-details-marker { display: none; }
.nav-panel {
    position: absolute;
    top: calc(100% + 0.75rem);
    left: 0;
    transform: none;
    width: min(760px, 92vw);
    background: var(--surface-color);
    color: var(--text-main);
    border-radius: var(--radius);
    border: 1px solid var(--border-color);
    padding: 1.25rem;
    box-shadow: var(--shadow-lg);
    display: none;
    z-index: 30;
}
.nav-dropdown[open] .nav-panel { display: block; }
.nav-panel-title {
    display: block;
    font-size: 0.75rem;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--text-muted);
    margin-bottom: 0.75rem;
}
.nav-panel-inner {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(170px, 1fr));
    gap: 1rem;
}
.nav-group-title {
    font-weight: 700;
    margin-bottom: 0.5rem;
    display: block;
}
.nav-group-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
}
.nav-group-list a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
}
.nav-group-list a:hover { color: var(--primary); }
.nav-more {
    display: inline-block;
    margin-top: 0.55rem;
    font-weight: 600;
    color: var(--primary);
    text-decoration: none;
}

@media (max-width: 720px) {
    .nav-container { justify-content: flex-start; }
    .nav-panel {
        position: static;
        transform: none;
        width: 100%;
        margin-top: 0.75rem;
    }
}
.featured-image-section {
    margin-top: 2rem;
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
    animation: fadeInUp 0.5s ease both;
}
.featured-image-section img.featured-image {
    width: 100%;
    height: auto;
    display: block;
    object-fit: cover;
    max-height: 240px;
    transition: transform var(--transition-slow);
}
.featured-image-section:hover img.featured-image {
    transform: scale(1.03);
}
.home-featured {
    padding: 1.5rem;
    background: var(--surface-color);
}
.home-featured .home-featured-grid {
    display: grid;
    grid-template-columns: minmax(0, 1.2fr) minmax(0, 1fr);
    gap: 1.5rem;
    align-items: center;
}
.home-featured .featured-media {
    border-radius: var(--radius-sm);
    overflow: hidden;
    box-shadow: var(--shadow-md);
}
.home-featured img.featured-image {
    max-height: 260px;
}
.home-featured .featured-copy h2 {
    margin: 0.6rem 0 0.8rem;
}
@media (max-width: 720px) {
    .home-featured .home-featured-grid {
        grid-template-columns: 1fr;
    }
}
    transform: scale(1.03);
}

/* ── Converter Box — Glassmorphism ─────────────────────── */
.converter-box {
    background: var(--surface-glass);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    padding: 2rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg), var(--shadow-glow);
    margin-top: 2rem;
    position: relative;
    border: 1px solid var(--border-color);
    animation: fadeInUp 0.5s ease 0.1s both;
}

@media (max-width: 600px) {
    .converter-box {
        position: sticky;
        top: 0;
        margin-top: 0;
        border-radius: 0 0 var(--radius) var(--radius);
        border-top: none;
        padding: 1.5rem 1rem;
        z-index: 100;
    }
}

/* ── Input Groups ──────────────────────────────────────── */
.input-group { margin-bottom: 1rem; }
.input-group label {
    display: block;
    font-weight: 600;
    margin-bottom: 0.5rem;
    font-size: 0.95rem;
    color: var(--text-secondary);
}

.input-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

.input-wrapper input {
    width: 100%;
    padding: 1rem 3.5rem 1rem 1.25rem;
    font-size: 1.3rem;
    font-family: inherit;
    font-weight: 600;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-sm);
    background: var(--surface-color);
    color: var(--text-main);
    outline: none;
    transition: var(--transition);
}

.input-wrapper input:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 4px var(--primary-glow);
}

.input-wrapper input::placeholder {
    color: var(--text-muted);
    font-weight: 400;
}

input[type=number]::-webkit-inner-spin-button,
input[type=number]::-webkit-outer-spin-button {
    -webkit-appearance: none;
    appearance: none;
    margin: 0;
}
input[type=number] {
    -moz-appearance: textfield;
    appearance: textfield;
}

.unit-label {
    position: absolute;
    right: 1rem;
    font-weight: 700;
    color: var(--primary);
    font-size: 0.9rem;
    letter-spacing: 0.02em;
    text-transform: uppercase;
}

/* ── Swap Controls ─────────────────────────────────────── */
.controls {
    display: flex;
    justify-content: center;
    margin: 0.75rem 0;
}

.icon-btn {
    background: var(--surface-color);
    border: 2px solid var(--border-color);
    border-radius: 50%;
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: var(--primary);
    transition: var(--transition);
    position: relative;
}
.icon-btn:hover {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
    transform: rotate(180deg) scale(1.1);
    box-shadow: var(--shadow-glow);
}
.icon-btn:focus-visible {
    outline: 3px solid var(--primary);
    outline-offset: 3px;
}

/* ── Precision Control ─────────────────────────────────── */
.precision-control {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-top: 1rem;
    justify-content: flex-end;
    font-size: 0.875rem;
    color: var(--text-muted);
}
.precision-control select {
    padding: 0.35rem 0.5rem;
    border-radius: 6px;
    border: 1px solid var(--border-color);
    background: var(--surface-color);
    color: var(--text-main);
    font-family: inherit;
}

/* ── Action Buttons ────────────────────────────────────── */
.actions {
    display: flex;
    gap: 0.75rem;
    margin-top: 1.5rem;
}

.btn {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.875rem 1.5rem;
    font-size: 0.95rem;
    font-weight: 600;
    font-family: inherit;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
    border: none;
    position: relative;
    overflow: hidden;
}

.primary-btn {
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-mid));
    color: white;
    box-shadow: 0 4px 14px var(--primary-glow);
}
.primary-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px var(--primary-glow);
}
.primary-btn:active { transform: translateY(0); }
.primary-btn:focus-visible {
    outline: 3px solid var(--primary);
    outline-offset: 3px;
}

.secondary-btn {
    background: var(--surface-color);
    color: var(--text-main);
    border: 1.5px solid var(--border-color);
}
.secondary-btn:hover {
    background: var(--bg-subtle);
    border-color: var(--border-strong);
    transform: translateY(-1px);
}
.secondary-btn:focus-visible {
    outline: 3px solid var(--primary);
    outline-offset: 3px;
}

.feedback {
    text-align: center;
    color: #10b981;
    font-weight: 600;
    margin-top: 1rem;
    opacity: 0;
    transform: translateY(-5px);
    transition: var(--transition);
    font-size: 0.9rem;
}
.feedback.show { opacity: 1; transform: translateY(0); }

/* ── Content Sections ──────────────────────────────────── */
.content-section {
    margin-top: 3rem;
    animation: fadeInUp 0.5s ease both;
}
.content-section:nth-child(2) { animation-delay: 0.1s; }
.content-section:nth-child(3) { animation-delay: 0.15s; }
.content-section:nth-child(4) { animation-delay: 0.2s; }
.content-section:nth-child(5) { animation-delay: 0.25s; }
.content-section:nth-child(6) { animation-delay: 0.3s; }

.content-section h2 {
    font-size: 1.45rem;
    font-weight: 700;
    margin-bottom: 1.25rem;
    letter-spacing: -0.02em;
    color: var(--text-main);
}

/* ── Conversion Table ──────────────────────────────────── */
.grid-table { display: grid; grid-template-columns: 1fr; }
.conversion-table {
    width: 100%;
    border-collapse: collapse;
    background: var(--surface-color);
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
}
.conversion-table th,
.conversion-table td {
    padding: 0.9rem 1.1rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
    font-size: 0.95rem;
}
.conversion-table th {
    background: var(--bg-subtle);
    font-weight: 700;
    color: var(--text-secondary);
    text-transform: uppercase;
    font-size: 0.8rem;
    letter-spacing: 0.05em;
}
.conversion-table tbody tr:hover {
    background: var(--bg-subtle);
}
.conversion-table tbody tr:nth-child(even) {
    background: rgba(99, 102, 241, 0.03);
}

/* ── Info Grid & Cards ─────────────────────────────────── */
.info-section h3 {
    font-size: 1.15rem;
    margin-top: 1rem;
    margin-bottom: 0.5rem;
    font-weight: 700;
}

.info-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.25rem;
}
@media (max-width: 600px) { .info-grid { grid-template-columns: 1fr; } }

.info-card {
    background: var(--surface-color);
    padding: 1.5rem;
    border-radius: var(--radius);
    border: 1px solid var(--border-color);
    transition: var(--transition);
}
.info-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary);
}
.info-card p {
    color: var(--text-muted);
    line-height: 1.7;
    font-size: 0.95rem;
}

.how-to-guide {
    background: var(--surface-color);
    padding: 1.5rem;
    border-radius: var(--radius);
    border: 1px solid var(--border-color);
}
.how-to-guide p {
    color: var(--text-muted);
    line-height: 1.7;
}

/* ── Formula Box ───────────────────────────────────────── */
.formula-box {
    background: var(--surface-color);
    padding: 1.5rem;
    border-radius: var(--radius);
    border: 1px solid var(--border-color);
    border-left: 4px solid var(--primary);
    font-family: 'JetBrains Mono', ui-monospace, monospace;
}
.formula-box p { margin: 0.5rem 0; color: var(--text-secondary); }
.formula-box code {
    background: var(--bg-subtle);
    padding: 0.2em 0.5em;
    border-radius: 4px;
    font-weight: 600;
    color: var(--primary);
}

/* ── SVG Diagram Container ─────────────────────────────── */
.svg-container {
    width: 100%;
    overflow: hidden;
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    padding: 1.25rem;
    min-height: 130px;
    display: flex;
    justify-content: center;
    align-items: center;
}
.diagram-caption {
    text-align: center;
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-top: 0.5rem;
    font-style: italic;
}
.diagram-subsection {
    margin-top: 1.5rem;
}
.diagram-subsection h3 {
    margin: 0 0 0.75rem;
}

/* ── FAQ Accordion ─────────────────────────────────────── */
.faq-container {
    background: var(--surface-color);
    border-radius: var(--radius);
    border: 1px solid var(--border-color);
    overflow: hidden;
}
.faq-item { border-bottom: 1px solid var(--border-color); }
.faq-item:last-child { border-bottom: none; }
.faq-question {
    width: 100%;
    text-align: left;
    padding: 1.15rem 1.25rem;
    background: none;
    border: none;
    font-size: 1rem;
    font-weight: 600;
    font-family: inherit;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: var(--text-main);
    transition: var(--transition-fast);
}
.faq-question:hover { background: var(--bg-subtle); }
.faq-question:focus-visible {
    outline: 3px solid var(--primary);
    outline-offset: -3px;
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.35s ease, padding 0.35s ease;
    padding: 0 1.25rem;
    color: var(--text-muted);
    line-height: 1.7;
}
.faq-question[aria-expanded="true"] + .faq-answer {
    max-height: 300px;
    padding: 0 1.25rem 1.25rem 1.25rem;
}

.faq-icon {
    transition: transform 0.3s ease;
    color: var(--primary);
    font-size: 1.3rem;
    font-weight: 700;
    flex-shrink: 0;
    margin-left: 1rem;
}
.faq-question[aria-expanded="true"] .faq-icon {
    transform: rotate(45deg);
}

/* ── Related Tools ─────────────────────────────────────── */
.related-ul {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
}
.related-ul a {
    display: inline-flex;
    align-items: center;
    padding: 0.6rem 1.15rem;
    background: var(--surface-color);
    border: 1.5px solid var(--border-color);
    border-radius: var(--radius-sm);
    text-decoration: none;
    color: var(--primary);
    font-weight: 600;
    font-size: 0.9rem;
    transition: var(--transition);
}
.related-ul a:hover {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px var(--primary-glow);
}
.related-ul a:focus-visible {
    outline: 3px solid var(--primary);
    outline-offset: 3px;
}

/* ── Footer ────────────────────────────────────────────── */
.footer {
    margin-top: 3rem;
    background: var(--surface-color);
    border-top: 1px solid var(--border-color);
    padding: 2.5rem 0 2rem;
    color: var(--text-secondary);
}
.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 1.5rem;
    text-align: left;
}
.footer-col h3 {
    font-size: 0.95rem;
    margin-bottom: 0.6rem;
}
.footer-col p {
    color: var(--text-muted);
}
.footer-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
}
.footer-list a {
    color: var(--text-secondary);
    text-decoration: none;
}
.footer-list a:hover { color: var(--primary); }
.footer-bottom {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    align-items: center;
    gap: 0.75rem;
    border-top: 1px solid var(--border-color);
    margin-top: 2rem;
    padding-top: 1.5rem;
    font-size: 0.85rem;
    color: var(--text-muted);
}
.footer-meta {
    color: var(--text-muted);
}
.border-top {
    border-top: 1px solid var(--border-color);
    padding-top: 2rem;
}

/* ── Utilities ─────────────────────────────────────────── */
.mt-4 { margin-top: 2rem; }
.mb-6 { margin-bottom: 4rem; }

/* ── Responsive ────────────────────────────────────────── */
@media (max-width: 600px) {
    .header h1 { font-size: 1.3rem; }
    .content-section h2 { font-size: 1.25rem; }
    .actions { flex-direction: column; }
    .btn { padding: 0.8rem 1rem; }
}

/* ── Focus accessibility ───────────────────────────────── */
:focus-visible {
    outline: 3px solid var(--primary);
    outline-offset: 2px;
}

/* ── Selection color ───────────────────────────────────── */
::selection {
    background: var(--primary);
    color: #fff;
}

/* === Category & Navigation Enhancements === */
.breadcrumbs {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    font-size: 0.9rem;
    color: var(--text-muted);
    margin: 1.25rem 0 0.5rem;
}
.breadcrumbs a {
    color: var(--text-muted);
    text-decoration: none;
}
.breadcrumbs a:hover {
    color: var(--primary);
}

.intro-section p {
    font-size: 1rem;
    color: var(--text-secondary);
}

.steps-list {
    list-style: decimal inside;
    display: grid;
    gap: 0.5rem;
    padding-left: 0;
    color: var(--text-secondary);
}

.category-grid .category-list,
.tool-grid .tool-list {
    list-style: none;
    padding: 0;
    margin: 0;
    display: grid;
    gap: 1rem;
}

.category-card,
.tool-card {
    background: var(--surface-glass);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    box-shadow: var(--shadow-sm);
    transition: transform var(--transition), box-shadow var(--transition);
}

.category-card a,
.tool-card a {
    display: block;
    padding: 1.25rem;
    text-decoration: none;
    color: inherit;
}

.category-card:hover,
.tool-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
}

.category-card h3,
.tool-card h3 {
    margin-bottom: 0.4rem;
    font-size: 1.1rem;
    color: var(--text-main);
}

.category-card p,
.tool-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.category-count {
    display: inline-block;
    margin-top: 0.5rem;
    font-size: 0.85rem;
    color: var(--text-muted);
}

/* === Homepage Hero & Cards === */
.pill {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.25rem 0.75rem;
    border-radius: 999px;
    font-size: 0.75rem;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    background: rgba(255, 255, 255, 0.2);
    color: #ffffff;
}

.hero-section {
    margin-top: 1.5rem;
    padding: 2rem;
    border-radius: var(--radius);
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.16), rgba(167, 139, 250, 0.16));
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-lg);
}

.hero-section h2 {
    font-size: clamp(1.6rem, 2.6vw, 2.3rem);
    margin: 0.6rem 0 0.8rem;
}

.hero-section p {
    color: var(--text-secondary);
}

.hero-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 0.75rem;
    margin-top: 1.25rem;
}

.stat-card {
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    padding: 0.75rem 1rem;
    box-shadow: var(--shadow-sm);
    display: block;
    text-decoration: none;
    color: inherit;
    transition: var(--transition-fast);
    cursor: pointer;
}
.stat-card:hover {
    transform: translateY(-2px);
    border-color: var(--primary);
    box-shadow: var(--shadow-md);
}

.stat-number {
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--text-main);
}

.stat-label {
    display: block;
    font-size: 0.8rem;
    color: var(--text-muted);
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1rem;
    margin-top: 1.5rem;
}

.feature-card {
    padding: 1.25rem;
    border-radius: var(--radius);
    background: var(--surface-glass);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
}

.feature-icon {
    display: inline-flex;
    width: 36px;
    height: 36px;
    border-radius: 12px;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    color: #ffffff;
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    margin-bottom: 0.75rem;
}

/* === Category + Tool Lists === */
.category-grid .category-list,
.tool-grid .tool-list {
    grid-template-columns: 1fr;
}

@media (min-width: 900px) {
    .category-grid .category-list {
        grid-template-columns: repeat(2, 1fr);
    }
}

.category-card a,
.tool-card a {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.card-badge {
    width: 44px;
    height: 44px;
    border-radius: 14px;
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    color: #ffffff;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.9rem;
    letter-spacing: 0.05em;
    flex-shrink: 0;
}

.card-content {
    flex: 1;
}

.card-meta {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 88px;
    padding: 0.35rem 0.75rem;
    border-radius: 999px;
    font-size: 0.8rem;
    color: var(--text-secondary);
    background: var(--bg-subtle);
    border: 1px solid var(--border-color);
}

.card-arrow {
    margin-left: auto;
    font-size: 1.2rem;
    color: var(--text-muted);
    transition: transform var(--transition), color var(--transition);
}

.tool-card a:hover .card-arrow,
.category-card a:hover .card-arrow {
    transform: translateX(4px);
    color: var(--primary);
}

/* === Section Visuals === */
.section-visual {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 0.75rem;
    margin-top: 0.75rem;
}

.visual-card,
.visual-step {
    background: var(--surface-glass);
    border: 1px solid var(--border-color);
    outline: 1px solid rgba(0,0,0,0);
    border-radius: var(--radius-sm);
    padding: 0.9rem 1rem;
    box-shadow: var(--shadow-sm);
}

.visual-label {
    display: block;
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-muted);
    margin-bottom: 0.35rem;
}

.visual-chips {
    display: flex;
    flex-wrap: wrap;
    gap: 0.6rem;
}

.visual-chip {
    border: 1px solid var(--border-color);
    outline: 1px solid rgba(0,0,0,0);
    border-radius: 999px;
    padding: 0.45rem 0.9rem;
    background: var(--surface-color);
    color: var(--text-main);
    font-weight: 600;
    cursor: pointer;
    transition: transform var(--transition), box-shadow var(--transition);
}

.visual-chip:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.visual-chip .chip-arrow {
    margin: 0 0.35rem;
    color: var(--text-muted);
}

.visual-steps {
    align-items: center;
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
}

.visual-equals {
    font-size: 1.25rem;
    color: var(--text-muted);
    align-self: center;
    justify-self: center;
}

.slider-row {
    margin-top: 1rem;
    display: grid;
    gap: 0.35rem;
}

.slider-row input[type="range"] {
    width: 100%;
}

.visual-diagram {
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
}

.visual-info {
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    margin-bottom: 1rem;
}

.visual-faq,
.visual-related {
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    margin-bottom: 1rem;
}

/* === Demo Section === */
.demo-section {
    margin-top: 1.5rem;
}

.demo-card {
    border: 1px solid var(--border-color);
    outline: 1px solid rgba(0,0,0,0);
    border-radius: var(--radius);
    padding: 1.5rem;
    background: var(--surface-glass);
    box-shadow: var(--shadow-md);
}

.demo-controls {
    margin-top: 0.75rem;
    display: flex;
    flex-direction: column;
    gap: 0.6rem;
}

.demo-controls label {
    display: block;
    margin-bottom: 0;
    color: var(--text-secondary);
}

.demo-input-row {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    padding: 0.35rem 0.6rem;
}
.demo-input-row input {
    border: none;
    background: transparent;
    flex: 1;
    font-size: 1rem;
    color: var(--text-main);
    outline: none;
}
.demo-unit {
    font-weight: 600;
    color: var(--text-muted);
}
.demo-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}
.demo-btn,
.demo-chip {
    border: 1px solid var(--border-color);
    background: var(--surface-color);
    color: var(--text-main);
    padding: 0.35rem 0.85rem;
    border-radius: 999px;
    cursor: pointer;
    font-weight: 600;
    transition: var(--transition-fast);
}
.demo-btn {
    background: var(--primary);
    color: #fff;
    border-color: transparent;
}
.demo-btn:hover {
    background: var(--primary-hover);
}
.demo-chip:hover {
    border-color: var(--primary);
    color: var(--primary);
    box-shadow: var(--shadow-sm);
}
.demo-output {
    margin-top: 1rem;
    display: flex;
    gap: 0.5rem;
    align-items: center;
    font-weight: 700;
}

.demo-arrow {
    color: var(--text-muted);
}

/* === Card Outline Enhancements === */
.category-card,
.tool-card,
.feature-card {
    outline: 1px solid var(--border-color);
    outline-offset: -1px;
}

.tool-card a {
    align-items: center;
}