/* ===== RESET & BASE ===== */
        *,
        *::before,
        *::after {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
        }
        :root {
            --brand-dark: #164B36;
            --brand-mid: #2D7A5A;
            --brand-light: #7FD996;
            --accent: #F5A623;
            --bg: #F8FAF9;
            --surface: #FFFFFF;
            --surface-alt: #ECF3EF;
            --text-primary: #1A2E26;
            --text-secondary: #3D5A4E;
            --text-muted: #6A7F76;
            --border: #D5E3DC;
            --radius: 16px;
            --shadow: 0 8px 30px rgba(22, 75, 54, 0.10);
            --font: 'Inter', system-ui, -apple-system, sans-serif;
            --heading-font: 'Outfit', var(--font);
            --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
            --max-width: 1200px;
            --header-height: 70px;
            color-scheme: light dark;
        }
        [data-theme="dark"] {
            --bg: #0F1A15;
            --surface: #1A2E26;
            --surface-alt: #243D33;
            --text-primary: #E8F0EC;
            --text-secondary: #B8CEC4;
            --text-muted: #8AA396;
            --border: #2D4A3E;
            --shadow: 0 8px 30px rgba(0, 0, 0, 0.5);
        }
        html {
            scroll-behavior: smooth;
        }
        body {
            font-family: var(--font);
            background: var(--bg);
            color: var(--text-primary);
            line-height: 1.6;
            transition: background var(--transition), color var(--transition);
        }
        a {
            color: var(--brand-dark);
            text-decoration: none;
        }
        a:hover {
            color: var(--brand-mid);
        }
        img,
        svg {
            display: block;
            max-width: 100%;
        }
        .skip-link {
            position: absolute;
            top: -999px;
            left: 50%;
            transform: translateX(-50%);
            background: var(--brand-dark);
            color: #fff;
            padding: 12px 24px;
            border-radius: 8px;
            z-index: 9999;
            font-weight: 600;
        }
        .skip-link:focus {
            top: 12px;
        }

        /* ===== UTILITY ===== */
        .section-inner {
            max-width: var(--max-width);
            margin: 0 auto;
            padding: 0 24px;
        }
        .narrow {
            max-width: 820px;
        }
        .eyebrow {
            display: inline-block;
            font-size: 0.75rem;
            font-weight: 600;
            text-transform: uppercase;
            letter-spacing: 0.08em;
            color: var(--brand-mid);
            background: var(--surface-alt);
            padding: 4px 14px;
            border-radius: 40px;
            margin-bottom: 12px;
        }
        .eyebrow.center {
            display: table;
            margin-left: auto;
            margin-right: auto;
        }
        .section-title {
            font-family: var(--heading-font);
            font-size: clamp(1.6rem, 4vw, 2.4rem);
            font-weight: 700;
            line-height: 1.2;
            margin-bottom: 8px;
        }
        .section-title.center {
            text-align: center;
        }
        .section-sub {
            color: var(--text-secondary);
            max-width: 600px;
            margin: 0 auto 32px;
            text-align: center;
        }

        /* ===== BUTTONS ===== */
        .btn {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            padding: 12px 28px;
            border-radius: 60px;
            font-weight: 600;
            font-size: 0.95rem;
            border: none;
            cursor: pointer;
            transition: all var(--transition);
            font-family: var(--font);
            background: var(--surface);
            color: var(--text-primary);
            box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
        }
        .btn-primary {
            background: var(--brand-dark);
            color: #fff;
            box-shadow: 0 4px 14px rgba(22, 75, 54, 0.3);
        }
        .btn-primary:hover {
            background: var(--brand-mid);
            transform: translateY(-2px);
            box-shadow: 0 8px 24px rgba(22, 75, 54, 0.35);
        }
        .btn-ghost {
            background: transparent;
            color: var(--text-primary);
            box-shadow: none;
            border: 1.5px solid var(--border);
        }
        .btn-ghost:hover {
            background: var(--surface-alt);
            border-color: var(--brand-mid);
        }
        .btn-ghost-inverse {
            background: transparent;
            color: #fff;
            border: 1.5px solid rgba(255, 255, 255, 0.4);
        }
        .btn-ghost-inverse:hover {
            background: rgba(255, 255, 255, 0.12);
            border-color: #fff;
        }
        .btn-outline {
            background: transparent;
            border: 1.5px solid var(--border);
            color: var(--text-secondary);
            padding: 10px 20px;
            font-size: 0.85rem;
        }
        .btn-outline:hover {
            border-color: var(--brand-mid);
            color: var(--brand-dark);
            background: var(--surface-alt);
        }
        .btn:disabled {
            opacity: 0.6;
            pointer-events: none;
        }

        /* ===== HEADER ===== */
        .site-header {
            position: sticky;
            top: 0;
            z-index: 1000;
            background: var(--surface);
            border-bottom: 1px solid var(--border);
            transition: background var(--transition), border var(--transition);
            height: var(--header-height);
            display: flex;
            align-items: center;
        }
        .header-inner {
            max-width: var(--max-width);
            width: 100%;
            margin: 0 auto;
            padding: 0 24px;
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 16px;
        }
        .brand {
            display: flex;
            align-items: center;
            gap: 10px;
            font-weight: 700;
            font-size: 1.2rem;
            color: var(--text-primary);
            flex-shrink: 0;
        }
        .brand-mark {
            display: flex;
            align-items: center;
        }
        .brand-text {
            font-family: var(--heading-font);
        }
        .brand-dot {
            color: var(--brand-light);
        }
        .brand-text.light {
            color: #fff;
        }

        .main-nav {
            display: flex;
            align-items: center;
        }
        .nav-list {
            display: flex;
            list-style: none;
            gap: 8px;
            align-items: center;
        }
        .nav-link {
            padding: 8px 16px;
            border-radius: 40px;
            font-weight: 500;
            font-size: 0.9rem;
            color: var(--text-secondary);
            transition: all var(--transition);
            display: flex;
            align-items: center;
            gap: 4px;
            background: transparent;
            border: none;
            cursor: pointer;
            font-family: var(--font);
        }
        .nav-link:hover {
            color: var(--text-primary);
            background: var(--surface-alt);
        }
        .nav-link .chev {
            transition: transform var(--transition);
        }
        .nav-item.has-mega {
            position: relative;
        }
        .nav-item.has-mega:hover .mega-panel {
            opacity: 1;
            visibility: visible;
            transform: translateY(0);
            pointer-events: auto;
        }
        .mega-panel {
            position: absolute;
            top: 100% ;
            left: 50%;
            transform: translateX(-50%) translateY(-6px);
            background: var(--surface);
            border: 1px solid var(--border);
            border-radius: var(--radius);
            box-shadow: var(--shadow);
            padding: 24px 28px;
            min-width: 520px;
            opacity: 0;
            visibility: hidden;
            pointer-events: none;
            transition: all var(--transition);
            z-index: 100;
        }
        .mega-grid {
            display: grid;
            grid-template-columns: 1fr 1fr 1fr;
            gap: 8px 20px;
        }
        .mega-link {
            display: flex;
            flex-direction: column;
            padding: 8px 12px;
            border-radius: 8px;
            transition: background var(--transition);
            color: var(--text-primary);
            font-size: 0.85rem;
        }
        .mega-link:hover {
            background: var(--surface-alt);
        }
        .mega-link strong {
            font-weight: 600;
        }
        .mega-link span {
            font-size: 0.75rem;
            color: var(--text-muted);
        }
        .mega-link.is-current {
            background: var(--surface-alt);
            border-left: 3px solid var(--brand-mid);
        }

        .header-actions {
            display: flex;
            align-items: center;
            gap: 8px;
            flex-shrink: 0;
        }
        .icon-btn {
            background: transparent;
            border: none;
            padding: 8px;
            border-radius: 40px;
            cursor: pointer;
            color: var(--text-secondary);
            transition: all var(--transition);
            display: flex;
            align-items: center;
            justify-content: center;
            width: 40px;
            height: 40px;
        }
        .icon-btn:hover {
            background: var(--surface-alt);
            color: var(--text-primary);
        }
        .icon-sun {
            display: block;
        }
        .icon-moon {
            display: none;
        }
        [data-theme="dark"] .icon-sun {
            display: none;
        }
        [data-theme="dark"] .icon-moon {
            display: block;
        }

        .nav-burger {
            display: none;
            flex-direction: column;
            gap: 5px;
            width: 40px;
            height: 40px;
            padding: 10px 8px;
        }
        .nav-burger span {
            display: block;
            height: 2.5px;
            background: var(--text-primary);
            border-radius: 4px;
            transition: all var(--transition);
            width: 24px;
        }
        .nav-burger[aria-expanded="true"] span:nth-child(1) {
            transform: rotate(45deg) translate(5px, 5px);
        }
        .nav-burger[aria-expanded="true"] span:nth-child(2) {
            opacity: 0;
        }
        .nav-burger[aria-expanded="true"] span:nth-child(3) {
            transform: rotate(-45deg) translate(5px, -5px);
        }

        /* ===== BREADCRUMB ===== */
        .breadcrumb-bar {
            background: var(--surface-alt);
            padding: 10px 24px;
            border-bottom: 1px solid var(--border);
            font-size: 0.8rem;
        }
        .breadcrumb {
            display: flex;
            flex-wrap: wrap;
            list-style: none;
            gap: 6px 12px;
            max-width: var(--max-width);
            margin: 0 auto;
        }
        .breadcrumb li {
            display: flex;
            align-items: center;
            gap: 6px;
        }
        .breadcrumb li+li::before {
            content: "›";
            color: var(--text-muted);
            font-weight: 300;
        }
        .breadcrumb a {
            color: var(--text-secondary);
        }
        .breadcrumb a:hover {
            color: var(--brand-dark);
        }
        .breadcrumb [aria-current="page"] {
            color: var(--text-primary);
            font-weight: 500;
        }

        /* ===== HERO ===== */
        .hero {
            padding: 48px 24px 56px;
            background: var(--surface-alt);
            border-bottom: 1px solid var(--border);
            transition: background var(--transition);
        }
        .hero-inner {
            max-width: var(--max-width);
            margin: 0 auto;
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 40px;
            align-items: center;
        }
        .hero-copy {
            display: flex;
            flex-direction: column;
            gap: 16px;
        }
        .hero-copy h1 {
            font-family: var(--heading-font);
            font-size: clamp(2rem, 5vw, 3rem);
            font-weight: 800;
            line-height: 1.1;
            letter-spacing: -0.02em;
        }
        .hero-sub {
            font-size: 1.1rem;
            color: var(--text-secondary);
            max-width: 520px;
        }
        .hero-cta {
            display: flex;
            flex-wrap: wrap;
            gap: 12px;
            margin-top: 4px;
        }
        .hero-stats {
            display: flex;
            gap: 32px;
            list-style: none;
            margin-top: 8px;
            flex-wrap: wrap;
        }
        .hero-stats li {
            display: flex;
            flex-direction: column;
            font-size: 0.85rem;
            color: var(--text-secondary);
        }
        .hero-stats li strong {
            font-size: 1.3rem;
            color: var(--text-primary);
            font-weight: 700;
        }
        .hero-visual {
            display: flex;
            justify-content: center;
            align-items: center;
        }
        .hero-svg {
            max-width: 320px;
            width: 100%;
            height: auto;
        }

        /* ===== REF STRIP ===== */
        .ref-strip {
            background: var(--surface);
            border-bottom: 1px solid var(--border);
            padding: 16px 24px;
            transition: background var(--transition);
        }
        .ref-strip-inner {
            max-width: var(--max-width);
            margin: 0 auto;
            display: flex;
            align-items: center;
            gap: 20px;
            flex-wrap: wrap;
        }
        .ref-title {
            font-size: 0.8rem;
            font-weight: 600;
            text-transform: uppercase;
            letter-spacing: 0.04em;
            color: var(--text-muted);
            white-space: nowrap;
        }
        .ref-scroll {
            display: flex;
            gap: 10px 18px;
            flex-wrap: wrap;
            overflow-x: auto;
            padding-bottom: 4px;
            scrollbar-width: thin;
        }
        .ref-scroll a {
            font-size: 0.85rem;
            color: var(--text-secondary);
            white-space: nowrap;
            padding: 4px 0;
            border-bottom: 2px solid transparent;
            transition: all var(--transition);
        }
        .ref-scroll a:hover {
            color: var(--brand-dark);
            border-bottom-color: var(--brand-light);
        }

        /* ===== FEATURES ===== */
        .features {
            padding: 60px 24px;
            background: var(--bg);
            transition: background var(--transition);
        }
        .feature-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
            gap: 24px;
            margin-top: 24px;
        }
        .feature-card {
            background: var(--surface);
            padding: 24px 20px;
            border-radius: var(--radius);
            border: 1px solid var(--border);
            transition: all var(--transition);
        }
        .feature-card:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow);
        }
        .feature-icon {
            font-size: 2rem;
            margin-bottom: 8px;
        }
        .feature-card h3 {
            font-family: var(--heading-font);
            font-size: 1.05rem;
            font-weight: 600;
            margin-bottom: 4px;
        }
        .feature-card p {
            font-size: 0.9rem;
            color: var(--text-secondary);
        }

        /* ===== CALCULATOR ===== */
        .calculator-section {
            padding: 60px 24px;
            background: var(--surface);
            transition: background var(--transition);
        }
        .ghg-form {
            max-width: 780px;
            margin: 0 auto;
            background: var(--bg);
            padding: 32px 36px;
            border-radius: var(--radius);
            border: 1px solid var(--border);
            transition: background var(--transition);
        }
        .form-tabs {
            display: flex;
            gap: 4px;
            background: var(--surface-alt);
            padding: 4px;
            border-radius: 40px;
            margin-bottom: 28px;
            flex-wrap: wrap;
        }
        .tab-btn {
            flex: 1;
            min-width: 80px;
            padding: 10px 18px;
            border: none;
            border-radius: 40px;
            font-weight: 600;
            font-size: 0.85rem;
            cursor: pointer;
            transition: all var(--transition);
            background: transparent;
            color: var(--text-secondary);
            font-family: var(--font);
        }
        .tab-btn.is-active {
            background: var(--surface);
            color: var(--text-primary);
            box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
        }
        .tab-btn:hover:not(.is-active) {
            color: var(--text-primary);
        }

        .tab-panel {
            display: none;
            animation: fadeUp 0.3s ease;
        }
        .tab-panel.is-active {
            display: block;
        }
        @keyframes fadeUp {
            from {
                opacity: 0;
                transform: translateY(8px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        .panel-legend {
            font-weight: 700;
            font-size: 1.05rem;
            margin-bottom: 16px;
            display: flex;
            align-items: center;
            gap: 10px;
            flex-wrap: wrap;
        }
        .scope-badge {
            font-size: 0.65rem;
            font-weight: 600;
            padding: 2px 12px;
            border-radius: 40px;
            background: var(--surface-alt);
            color: var(--text-muted);
            letter-spacing: 0.04em;
        }
        .scope-badge.scope-1 {
            background: #FEE9E7;
            color: #B34135;
        }
        .scope-badge.scope-2 {
            background: #E2F0E8;
            color: #1D6B4C;
        }
        .scope-badge.scope-3 {
            background: #E6EDF7;
            color: #2C5F8A;
        }
        [data-theme="dark"] .scope-badge.scope-1 {
            background: #3D1F1C;
            color: #E88A7D;
        }
        [data-theme="dark"] .scope-badge.scope-2 {
            background: #1A3D2E;
            color: #7FD996;
        }
        [data-theme="dark"] .scope-badge.scope-3 {
            background: #1D2A3D;
            color: #8AB8E8;
        }

        .field-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 18px 24px;
        }
        .field {
            display: flex;
            flex-direction: column;
            gap: 4px;
        }
        .field label {
            font-weight: 500;
            font-size: 0.9rem;
        }
        .field input,
        .field select {
            padding: 10px 14px;
            border-radius: 10px;
            border: 1.5px solid var(--border);
            background: var(--surface);
            color: var(--text-primary);
            font-family: var(--font);
            font-size: 0.95rem;
            transition: border var(--transition);
            width: 100%;
        }
        .field input:focus,
        .field select:focus {
            outline: none;
            border-color: var(--brand-mid);
            box-shadow: 0 0 0 3px rgba(45, 122, 90, 0.15);
        }
        .field input.is-error {
            border-color: #D94A4A;
        }
        .field input.is-error:focus {
            box-shadow: 0 0 0 3px rgba(217, 74, 74, 0.15);
        }
        .field-hint {
            font-size: 0.75rem;
            color: var(--text-muted);
        }
        .field-error {
            font-size: 0.75rem;
            color: #D94A4A;
            min-height: 18px;
        }

        .form-footer {
            margin-top: 28px;
            padding-top: 20px;
            border-top: 1px solid var(--border);
            display: flex;
            flex-direction: column;
            gap: 16px;
        }
        .checkbox-row {
            display: flex;
            align-items: center;
            gap: 10px;
            font-size: 0.9rem;
            cursor: pointer;
        }
        .checkbox-row input {
            width: 18px;
            height: 18px;
            accent-color: var(--brand-dark);
            cursor: pointer;
        }
        .form-actions {
            display: flex;
            gap: 12px;
            flex-wrap: wrap;
        }
        .form-actions .btn-primary {
            min-width: 180px;
            justify-content: center;
        }
        .btn-spinner {
            display: none;
            width: 18px;
            height: 18px;
            border: 2.5px solid rgba(255, 255, 255, 0.3);
            border-top-color: #fff;
            border-radius: 50%;
            animation: spin 0.7s linear infinite;
        }
        .btn.loading .btn-label {
            display: none;
        }
        .btn.loading .btn-spinner {
            display: block;
        }
        @keyframes spin {
            to {
                transform: rotate(360deg);
            }
        }
        .form-note {
            font-size: 0.85rem;
            color: var(--text-muted);
            min-height: 24px;
        }
        .form-note.success {
            color: var(--brand-mid);
        }
        .form-note.error {
            color: #D94A4A;
        }

        /* ===== RESULTS ===== */
        .results-section {
            padding: 60px 24px;
            background: var(--bg);
            transition: background var(--transition);
        }
        .results-section[hidden] {
            display: none;
        }
        .results-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 32px;
            max-width: 820px;
            margin: 0 auto 32px;
        }
        .result-total-card {
            background: var(--surface);
            padding: 32px 28px;
            border-radius: var(--radius);
            border: 1px solid var(--border);
            display: flex;
            flex-direction: column;
            justify-content: center;
            text-align: center;
        }
        .result-label {
            font-size: 0.85rem;
            font-weight: 500;
            color: var(--text-muted);
            text-transform: uppercase;
            letter-spacing: 0.04em;
        }
        .result-number {
            font-family: var(--heading-font);
            font-size: clamp(2.4rem, 5vw, 3.6rem);
            font-weight: 800;
            line-height: 1.1;
            color: var(--brand-dark);
        }
        .result-unit {
            font-size: 0.95rem;
            color: var(--text-secondary);
        }
        .result-equivalence {
            margin-top: 12px;
            font-size: 0.85rem;
            color: var(--text-muted);
            padding: 8px 16px;
            background: var(--surface-alt);
            border-radius: 40px;
            display: inline-block;
            align-self: center;
        }

        .result-chart-card {
            background: var(--surface);
            padding: 24px 20px;
            border-radius: var(--radius);
            border: 1px solid var(--border);
            display: flex;
            flex-direction: column;
            align-items: center;
        }
        .result-chart-card h3 {
            font-family: var(--heading-font);
            font-size: 1rem;
            font-weight: 600;
            margin-bottom: 12px;
        }
        .chart-wrap {
            width: 180px;
            height: 180px;
        }
        .donut-chart {
            width: 100%;
            height: 100%;
        }
        .legend {
            display: flex;
            flex-wrap: wrap;
            gap: 8px 16px;
            justify-content: center;
            list-style: none;
            margin-top: 12px;
            font-size: 0.8rem;
        }
        .legend li {
            display: flex;
            align-items: center;
            gap: 6px;
            color: var(--text-secondary);
        }
        .legend-dot {
            width: 12px;
            height: 12px;
            border-radius: 50%;
            flex-shrink: 0;
        }

        .scope-breakdown {
            max-width: 820px;
            margin: 0 auto 24px;
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
            gap: 16px;
        }
        .scope-card {
            background: var(--surface);
            padding: 16px 20px;
            border-radius: var(--radius);
            border: 1px solid var(--border);
            text-align: center;
        }
        .scope-card .scope-label {
            font-size: 0.75rem;
            font-weight: 600;
            text-transform: uppercase;
            letter-spacing: 0.04em;
            color: var(--text-muted);
        }
        .scope-card .scope-value {
            font-family: var(--heading-font);
            font-size: 1.4rem;
            font-weight: 700;
            color: var(--text-primary);
        }

        .result-table-wrap {
            max-width: 820px;
            margin: 0 auto 24px;
            overflow-x: auto;
            background: var(--surface);
            border-radius: var(--radius);
            border: 1px solid var(--border);
        }
        .result-table {
            width: 100%;
            border-collapse: collapse;
            font-size: 0.85rem;
        }
        .result-table th {
            background: var(--surface-alt);
            font-weight: 600;
            text-align: left;
            padding: 12px 16px;
            color: var(--text-secondary);
            font-size: 0.75rem;
            text-transform: uppercase;
            letter-spacing: 0.04em;
        }
        .result-table td {
            padding: 10px 16px;
            border-top: 1px solid var(--border);
            color: var(--text-secondary);
        }
        .result-table td:last-child {
            font-weight: 600;
            color: var(--text-primary);
        }

        .result-actions {
            display: flex;
            flex-wrap: wrap;
            gap: 10px;
            justify-content: center;
            max-width: 820px;
            margin: 0 auto;
        }
        .copy-toast {
            text-align: center;
            font-size: 0.85rem;
            margin-top: 10px;
            min-height: 24px;
            color: var(--brand-mid);
        }

        /* ===== HOW IT WORKS ===== */
        .how-it-works {
            padding: 60px 24px;
            background: var(--surface);
            transition: background var(--transition);
        }
        .steps-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
            gap: 24px;
            margin-top: 24px;
        }
        .step-card {
            background: var(--bg);
            padding: 24px 20px;
            border-radius: var(--radius);
            border: 1px solid var(--border);
            text-align: center;
        }
        .step-num {
            font-family: var(--heading-font);
            font-size: 2.2rem;
            font-weight: 800;
            color: var(--brand-light);
            opacity: 0.5;
            display: block;
            margin-bottom: 4px;
        }
        .step-card h3 {
            font-family: var(--heading-font);
            font-size: 1.05rem;
            font-weight: 600;
        }
        .step-card p {
            font-size: 0.9rem;
            color: var(--text-secondary);
        }

        /* ===== ARTICLE ===== */
        .article-section {
            padding: 60px 24px;
            background: var(--bg);
            transition: background var(--transition);
        }
        .article-body {
            margin-top: 20px;
            display: flex;
            flex-direction: column;
            gap: 18px;
            color: var(--text-secondary);
            line-height: 1.8;
        }
        .article-body p {
            font-size: 1rem;
        }
        .article-body strong {
            color: var(--text-primary);
        }

        /* ===== FAQ ===== */
        .faq-section {
            padding: 60px 24px;
            background: var(--surface);
            transition: background var(--transition);
        }
        .faq-list {
            margin-top: 24px;
            display: flex;
            flex-direction: column;
            gap: 8px;
        }
        .faq-item {
            background: var(--bg);
            border-radius: var(--radius);
            border: 1px solid var(--border);
            padding: 0 20px;
            transition: all var(--transition);
        }
        .faq-item summary {
            padding: 16px 0;
            font-weight: 600;
            cursor: pointer;
            list-style: none;
            display: flex;
            justify-content: space-between;
            align-items: center;
            font-size: 0.95rem;
            color: var(--text-primary);
        }
        .faq-item summary::-webkit-details-marker {
            display: none;
        }
        .faq-item summary::after {
            content: "▸";
            font-size: 1.2rem;
            color: var(--text-muted);
            transition: transform var(--transition);
        }
        .faq-item[open] summary::after {
            transform: rotate(90deg);
        }
        .faq-item p {
            padding: 0 0 18px 0;
            color: var(--text-secondary);
            font-size: 0.95rem;
            line-height: 1.7;
        }

        /* ===== CTA ===== */
        .cta-section {
            padding: 60px 24px;
            background: var(--brand-dark);
            color: #fff;
            text-align: center;
        }
        .cta-inner {
            display: flex;
            flex-direction: column;
            gap: 16px;
            align-items: center;
        }
        .cta-inner h2 {
            font-family: var(--heading-font);
            font-size: clamp(1.6rem, 3vw, 2.2rem);
            font-weight: 700;
        }
        .cta-inner p {
            opacity: 0.8;
            max-width: 500px;
        }
        .cta-buttons {
            display: flex;
            flex-wrap: wrap;
            gap: 12px;
            justify-content: center;
            margin-top: 4px;
        }

        /* ===== FOOTER ===== */
        .site-footer {
            background: var(--surface-alt);
            border-top: 1px solid var(--border);
            padding: 48px 24px 24px;
            transition: background var(--transition);
        }
        .footer-top {
            display: grid;
            grid-template-columns: 2fr 1fr 1fr 1fr 1fr;
            gap: 32px 24px;
            padding-bottom: 32px;
            border-bottom: 1px solid var(--border);
        }
        .footer-brand-col p {
            font-size: 0.85rem;
            color: var(--text-secondary);
            max-width: 280px;
        }
        .footer-brand-col .disclaimer {
            font-size: 0.7rem;
            color: var(--text-muted);
            margin-top: 8px;
            line-height: 1.5;
        }
        .footer-col h4 {
            font-size: 0.8rem;
            font-weight: 600;
            text-transform: uppercase;
            letter-spacing: 0.04em;
            color: var(--text-muted);
            margin-bottom: 10px;
        }
        .footer-col a {
            display: block;
            font-size: 0.85rem;
            color: var(--text-secondary);
            padding: 3px 0;
            transition: color var(--transition);
        }
        .footer-col a:hover {
            color: var(--text-primary);
        }
        .footer-bottom {
            padding-top: 20px;
            display: flex;
            flex-direction: column;
            gap: 6px;
            font-size: 0.8rem;
            color: var(--text-muted);
        }
        .footer-legal {
            font-size: 0.7rem;
            opacity: 0.7;
            max-width: 700px;
        }

        /* ===== COOKIE BANNER ===== */
        .cookie-banner {
            position: fixed;
            bottom: 0;
            left: 0;
            right: 0;
            background: var(--surface);
            border-top: 1px solid var(--border);
            padding: 16px 24px;
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 20px;
            flex-wrap: wrap;
            z-index: 9999;
            box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.06);
            transition: transform 0.4s ease, opacity 0.4s ease;
        }
        .cookie-banner[hidden] {
            display: none;
        }
        .cookie-banner p {
            font-size: 0.85rem;
            color: var(--text-secondary);
            flex: 1;
            min-width: 200px;
        }
        .cookie-banner a {
            color: var(--brand-dark);
            text-decoration: underline;
        }
        .cookie-actions {
            display: flex;
            gap: 8px;
            flex-shrink: 0;
        }
        .cookie-actions .btn {
            padding: 8px 20px;
            font-size: 0.8rem;
        }

        /* ===== BACK TO TOP ===== */
        .back-to-top {
            position: fixed;
            bottom: 24px;
            right: 24px;
            z-index: 999;
            background: var(--brand-dark);
            color: #fff;
            border: none;
            border-radius: 40px;
            width: 44px;
            height: 44px;
            display: flex;
            align-items: center;
            justify-content: center;
            cursor: pointer;
            box-shadow: 0 4px 16px rgba(22, 75, 54, 0.3);
            transition: all var(--transition);
            opacity: 0;
            transform: scale(0.8);
            pointer-events: none;
        }
        .back-to-top:not([hidden]) {
            opacity: 1;
            transform: scale(1);
            pointer-events: auto;
        }
        .back-to-top:hover {
            background: var(--brand-mid);
            transform: scale(1.05);
        }

        /* ===== RESPONSIVE ===== */
        @media (max-width: 900px) {
            .hero-inner {
                grid-template-columns: 1fr;
                text-align: center;
            }
            .hero-copy {
                align-items: center;
            }
            .hero-sub {
                max-width: 100%;
            }
            .hero-stats {
                justify-content: center;
            }
            .hero-visual {
                order: -1;
            }
            .hero-svg {
                max-width: 200px;
            }
            .footer-top {
                grid-template-columns: 1fr 1fr;
            }
            .mega-panel {
                min-width: 280px;
                left: 0;
                transform: none;
            }
            .mega-grid {
                grid-template-columns: 1fr 1fr;
            }
        }
        @media (max-width: 700px) {
            .nav-list {
                display: none;
                flex-direction: column;
                position: absolute;
                top: var(--header-height);
                left: 0;
                right: 0;
                background: var(--surface);
                padding: 16px 24px;
                border-bottom: 1px solid var(--border);
                box-shadow: var(--shadow);
                gap: 4px;
            }
            .nav-list.open {
                display: flex;
            }
            .nav-burger {
                display: flex;
            }
            .mega-panel {
                position: static;
                box-shadow: none;
                border: none;
                padding: 8px 0 0 16px;
                min-width: auto;
                opacity: 1;
                visibility: visible;
                pointer-events: auto;
                transform: none;
                display: none;
                background: transparent;
            }
            .nav-item.has-mega:hover .mega-panel {
                display: none;
            }
            .nav-item.has-mega.open .mega-panel {
                display: block;
            }
            .mega-grid {
                grid-template-columns: 1fr 1fr;
                gap: 4px;
            }
            .mega-link {
                padding: 6px 8px;
                font-size: 0.8rem;
            }

            .results-grid {
                grid-template-columns: 1fr;
            }
            .field-grid {
                grid-template-columns: 1fr;
            }
            .ghg-form {
                padding: 20px 16px;
            }
            .form-tabs {
                gap: 2px;
            }
            .tab-btn {
                font-size: 0.75rem;
                padding: 8px 12px;
                min-width: 60px;
            }
            .footer-top {
                grid-template-columns: 1fr;
                gap: 20px;
            }
            .cookie-banner {
                flex-direction: column;
                align-items: stretch;
                text-align: center;
            }
            .cookie-actions {
                justify-content: center;
            }
            .result-total-card {
                padding: 24px 16px;
            }
            .chart-wrap {
                width: 140px;
                height: 140px;
            }
        }
        @media (max-width: 480px) {
            .hero {
                padding: 32px 16px 40px;
            }
            .hero-copy h1 {
                font-size: 1.8rem;
            }
            .features,
            .calculator-section,
            .results-section,
            .how-it-works,
            .article-section,
            .faq-section,
            .cta-section {
                padding: 40px 16px;
            }
            .section-title {
                font-size: 1.4rem;
            }
            .btn {
                padding: 10px 20px;
                font-size: 0.85rem;
            }
            .form-actions {
                flex-direction: column;
            }
            .form-actions .btn {
                width: 100%;
                justify-content: center;
            }
        }