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

        :root {
            --primary-green: #10b981;
            --dark-green: #059669;
            --primary-teal: #14b8a6;
            --dark-teal: #0f766e;
            --bg-dark: #0f172a;
            --bg-light: #f8fafc;
            --text-dark: #1e293b;
            --text-light: #64748b;
            --accent: #34d399;
        }

        body {
            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
            line-height: 1.6;
            color: var(--text-dark);
            background: var(--bg-light);
        }

        /* Hero Section */
        .hero {
            background: linear-gradient(135deg, var(--bg-dark) 0%, #1e3a5f 100%);
            color: white;
            padding: 120px 20px 80px;
            text-align: center;
        }

        .hero h1 {
            font-size: 3rem;
            font-weight: 700;
            margin-bottom: 0.5rem;
            letter-spacing: -0.02em;
        }

        .hero .tagline {
            font-size: 1.5rem;
            color: var(--accent);
            margin-bottom: 2rem;
            font-weight: 300;
        }

        .hero p {
            font-size: 1.125rem;
            max-width: 600px;
            margin: 0 auto 2.5rem;
            color: #cbd5e1;
            line-height: 1.8;
        }

        .cta-buttons {
            display: flex;
            gap: 1rem;
            justify-content: center;
            flex-wrap: wrap;
        }

        .btn {
            display: inline-block;
            padding: 0.875rem 2rem;
            border-radius: 8px;
            text-decoration: none;
            font-weight: 600;
            transition: all 0.3s ease;
            font-size: 1rem;
        }

        .btn-primary {
            background: var(--primary-green);
            color: white;
        }

        .btn-primary:hover {
            background: var(--dark-green);
            transform: translateY(-2px);
            box-shadow: 0 10px 25px rgba(16, 185, 129, 0.3);
        }

        .btn-secondary {
            background: transparent;
            color: white;
            border: 2px solid var(--accent);
        }

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

        /* Container */
        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
        }

        section {
            padding: 80px 20px;
        }

        h2 {
            font-size: 2.5rem;
            font-weight: 700;
            margin-bottom: 1rem;
            color: var(--text-dark);
            text-align: center;
        }

        .section-intro {
            text-align: center;
            font-size: 1.125rem;
            color: var(--text-light);
            max-width: 700px;
            margin: 0 auto 3rem;
        }

        /* Course Section */
        .course-section {
            background: white;
        }

        .courses-grid {
            display: grid;
            grid-template-columns: repeat(2, 1fr);
            gap: 2rem;
            max-width: 1200px;
            margin: 0 auto;
            align-items: stretch;
        }

        .course-card {
            background: linear-gradient(135deg, var(--primary-green) 0%, var(--dark-green) 100%);
            border-radius: 16px;
            padding: 2.5rem;
            color: white;
            box-shadow: 0 20px 60px rgba(16, 185, 129, 0.2);
            display: flex;
            flex-direction: column;
        }

        .course-card--vibe {
            background: linear-gradient(135deg, var(--primary-teal) 0%, var(--dark-teal) 100%);
            box-shadow: 0 20px 60px rgba(20, 184, 166, 0.2);
        }

        .course-card--vibe .course-link {
            color: var(--dark-teal);
        }

        .course-card h3 {
            font-size: 1.75rem;
            margin-bottom: 1.5rem;
        }

        .course-card p {
            font-size: 1.0625rem;
            line-height: 1.8;
            margin-bottom: 1rem;
        }

        .course-card .course-link {
            display: inline-block;
            margin-top: auto;
            align-self: flex-start;
            padding: 0.875rem 2rem;
            background: white;
            color: var(--dark-green);
            text-decoration: none;
            border-radius: 8px;
            font-weight: 600;
            transition: all 0.3s ease;
        }

        .course-card .course-link:hover {
            transform: translateY(-2px);
            box-shadow: 0 10px 25px rgba(0, 0, 0, 0.15);
        }

        /* Testimonials Section */
        .testimonials-section {
            background: var(--bg-light);
            border-top: 1px solid #e2e8f0;
        }

        .testimonials-content {
            max-width: 800px;
            margin: 0 auto;
            background: white;
            padding: 2.5rem;
            border-radius: 12px;
            box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
            border-left: 4px solid var(--primary-green);
        }

        .testimonials-content p {
            font-size: 1.125rem;
            line-height: 1.8;
            color: var(--text-dark);
            margin-bottom: 1.5rem;
        }

        .testimonials-content p:first-of-type {
            color: var(--text-light);
            font-style: italic;
            font-size: 1rem;
        }

        .testimonials-content strong {
            color: var(--primary-green);
        }

        /* Services Section */
        .services-section {
            background: var(--bg-light);
        }

        .services-grid {
            display: grid;
            grid-template-columns: repeat(2, 1fr);
            gap: 2rem;
            max-width: 1200px;
            margin: 0 auto;
            align-items: stretch;
        }

        .service-card {
            background: white;
            padding: 2rem;
            border-radius: 12px;
            box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
            transition: all 0.3s ease;
            border-left: 4px solid var(--primary-green);
        }

        .service-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 12px 24px rgba(16, 185, 129, 0.15);
        }

        .service-card h3 {
            font-size: 1.5rem;
            color: var(--text-dark);
            margin-bottom: 1rem;
            display: flex;
            align-items: center;
            gap: 0.5rem;
        }

        .service-card .icon {
            font-size: 1.75rem;
        }

        .service-card p {
            color: var(--text-light);
            line-height: 1.7;
        }

        .service-subitem + .service-subitem {
            margin-top: 1.5rem;
            padding-top: 1.5rem;
            border-top: 1px solid #e2e8f0;
        }

        .service-subitem h4 {
            font-size: 1.1rem;
            color: var(--text-dark);
            margin-bottom: 0.5rem;
            font-weight: 600;
        }

        .service-subitem-link {
            display: inline-block;
            margin-top: 0.75rem;
            color: var(--primary-green);
            text-decoration: none;
            font-weight: 600;
            font-size: 0.95rem;
        }

        .service-subitem-link:hover {
            text-decoration: underline;
        }

        .service-card .booked-badge {
            display: inline-block;
            margin-top: 1rem;
            padding: 0.4rem 1rem;
            background: #f1f5f9;
            color: #475569;
            border-radius: 20px;
            font-size: 0.85rem;
            font-weight: 600;
            text-decoration: none;
        }

        /* About Section */
        .about-section {
            background: white;
            padding-bottom: 0;
        }

        .about-content {
            max-width: 800px;
            margin: 0 auto;
        }

        .about-content p {
            font-size: 1.125rem;
            line-height: 1.9;
            color: var(--text-dark);
            margin-bottom: 1.5rem;
        }

        .about-content .highlight {
            background: linear-gradient(135deg, rgba(16, 185, 129, 0.1) 0%, rgba(52, 211, 153, 0.1) 100%);
            padding: 1.5rem;
            border-radius: 8px;
            border-left: 4px solid var(--primary-green);
            margin: 2rem 0;
        }

        /* Writings Section */
        .writings-section {
            background: var(--bg-light);
        }

        .writings-list {
            max-width: 800px;
            margin: 0 auto;
            display: flex;
            flex-direction: column;
            gap: 1rem;
        }

        .writings-item {
            display: block;
            background: white;
            padding: 1.75rem 2rem;
            border-radius: 12px;
            box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
            border-left: 4px solid var(--primary-green);
            text-decoration: none;
            color: inherit;
            transition: all 0.3s ease;
        }

        .writings-item:hover {
            transform: translateY(-3px);
            box-shadow: 0 12px 24px rgba(16, 185, 129, 0.15);
        }

        .writings-item-date {
            display: block;
            font-size: 0.8rem;
            color: var(--text-light);
            text-transform: uppercase;
            letter-spacing: 0.05em;
            font-weight: 600;
            margin-bottom: 0.5rem;
        }

        .writings-item h3 {
            font-size: 1.4rem;
            color: var(--text-dark);
            margin-bottom: 0.5rem;
        }

        .writings-item p {
            color: var(--text-light);
            line-height: 1.6;
            font-size: 1rem;
        }

        /* Contact Section */
        .contact-section {
            background: var(--bg-dark);
            color: white;
            text-align: center;
        }

        .contact-section h2 {
            color: white;
        }

        .contact-section .section-intro {
            color: #cbd5e1;
        }

        .social-links {
            display: flex;
            gap: 1.5rem;
            justify-content: center;
            margin-top: 2rem;
        }

        .social-link {
            display: flex;
            align-items: center;
            gap: 0.75rem;
            padding: 1rem 2rem;
            background: rgba(255, 255, 255, 0.1);
            border-radius: 8px;
            color: white;
            text-decoration: none;
            font-weight: 600;
            transition: all 0.3s ease;
            backdrop-filter: blur(10px);
        }

        .social-link:hover {
            background: var(--primary-green);
            transform: translateY(-2px);
        }

        .social-link svg {
            width: 24px;
            height: 24px;
        }

        footer {
            background: #020617;
            color: #64748b;
            text-align: center;
            padding: 2rem;
            font-size: 0.875rem;
        }

        /* Responsive */
        @media (max-width: 768px) {
            .hero h1 {
                font-size: 2rem;
            }

            .hero .tagline {
                font-size: 1.25rem;
            }

            h2 {
                font-size: 2rem;
            }

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

            .course-card {
                padding: 2rem;
            }

            .course-card h3 {
                font-size: 1.5rem;
            }

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

            .social-links {
                flex-direction: column;
                align-items: center;
            }
        }

        /* ============================================
           Theme toggle button
           ============================================ */
        .theme-toggle {
            position: fixed;
            bottom: 1.5rem;
            right: 1.5rem;
            z-index: 200;
            width: 56px;
            height: 56px;
            border-radius: 50%;
            border: 2px solid #ff2d95;
            background: rgba(15, 23, 42, 0.85);
            color: #ff2d95;
            font-size: 1.5rem;
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: center;
            box-shadow: 0 0 20px rgba(255, 45, 149, 0.4), 0 0 40px rgba(0, 245, 255, 0.15);
            transition: transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease, color 0.3s ease;
            backdrop-filter: blur(8px);
            -webkit-backdrop-filter: blur(8px);
        }

        .theme-toggle:hover {
            transform: scale(1.1) rotate(15deg);
            box-shadow: 0 0 30px rgba(255, 45, 149, 0.7), 0 0 60px rgba(0, 245, 255, 0.4);
        }

        .theme-toggle:focus-visible {
            outline: 2px solid #00f5ff;
            outline-offset: 4px;
        }

        /* ============================================
           Cyberpunk theme
           ============================================ */
        body.cyberpunk {
            background: #0a0015;
            color: #e0e8ff;
        }

        body.cyberpunk .theme-toggle {
            border-color: #00f5ff;
            color: #00f5ff;
            box-shadow: 0 0 20px rgba(0, 245, 255, 0.6), 0 0 40px rgba(255, 45, 149, 0.3);
        }

        body.cyberpunk .theme-toggle:hover {
            box-shadow: 0 0 30px rgba(0, 245, 255, 0.8), 0 0 60px rgba(255, 45, 149, 0.5);
        }

        /* Scanlines overlay */
        body.cyberpunk::after {
            content: "";
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: repeating-linear-gradient(
                to bottom,
                transparent 0,
                transparent 2px,
                rgba(0, 245, 255, 0.035) 2px,
                rgba(0, 245, 255, 0.035) 3px
            );
            pointer-events: none;
            z-index: 150;
        }

        /* Gradient shift animation (hue rotates slowly across the page) */
        @keyframes gradientShift {
            0%, 100% { background-position: 0% 50%; }
            50% { background-position: 100% 50%; }
        }

        @keyframes hueDrift {
            0%, 100% { filter: hue-rotate(0deg); }
            50% { filter: hue-rotate(25deg); }
        }

        /* Hero */
        body.cyberpunk .hero {
            background: linear-gradient(135deg, #0a0015 0%, #1a0533 40%, #0d0221 100%);
            background-size: 220% 220%;
            animation: gradientShift 24s ease-in-out infinite;
        }

        body.cyberpunk .hero h1 {
            color: #fff;
            text-shadow: 0 0 20px #ff2d95, 0 0 40px rgba(255, 45, 149, 0.7);
        }

        body.cyberpunk .hero .tagline {
            color: #00f5ff;
            text-shadow: 0 0 15px rgba(0, 245, 255, 0.8);
        }

        body.cyberpunk .hero p {
            color: #c8d3ff;
        }

        /* Buttons */
        body.cyberpunk .btn-primary {
            background: linear-gradient(135deg, #ff2d95 0%, #b537f2 100%);
            color: #fff;
            box-shadow: 0 0 20px rgba(255, 45, 149, 0.55);
        }

        body.cyberpunk .btn-primary:hover {
            box-shadow: 0 0 30px rgba(255, 45, 149, 0.8), 0 0 60px rgba(181, 55, 242, 0.5);
            background: linear-gradient(135deg, #ff2d95 0%, #00f5ff 100%);
        }

        body.cyberpunk .btn-secondary {
            border-color: #00f5ff;
            color: #00f5ff;
            box-shadow: 0 0 10px rgba(0, 245, 255, 0.3);
        }

        body.cyberpunk .btn-secondary:hover {
            background: #00f5ff;
            color: #0a0015;
            box-shadow: 0 0 30px rgba(0, 245, 255, 0.7);
        }

        /* Section backgrounds */
        body.cyberpunk .course-section {
            background: #120826;
        }

        body.cyberpunk .testimonials-section {
            background: #0d0221;
            border-top-color: rgba(255, 45, 149, 0.2);
        }

        body.cyberpunk .services-section {
            background: #120826;
        }

        body.cyberpunk .about-section {
            background: #0d0221;
        }

        body.cyberpunk .writings-section {
            background: #120826;
        }

        body.cyberpunk .writings-item {
            background: rgba(15, 8, 38, 0.7);
            border-left-color: #ff2d95;
            box-shadow: 0 0 20px rgba(255, 45, 149, 0.2);
        }

        body.cyberpunk .writings-item:hover {
            box-shadow: 0 0 30px rgba(255, 45, 149, 0.45), 0 12px 24px rgba(0, 0, 0, 0.5);
        }

        body.cyberpunk .writings-item h3 {
            color: #fff;
        }

        body.cyberpunk .writings-item p {
            color: #a78bcc;
        }

        body.cyberpunk .writings-item-date {
            color: #00f5ff;
            text-shadow: 0 0 8px rgba(0, 245, 255, 0.4);
        }

        body.cyberpunk h2 {
            color: #fff;
            text-shadow: 0 0 18px rgba(255, 45, 149, 0.55);
        }

        body.cyberpunk .section-intro {
            color: #a78bcc;
        }

        /* Course cards */
        body.cyberpunk .course-card {
            background: linear-gradient(135deg, #ff2d95 0%, #b537f2 100%);
            background-size: 200% 200%;
            box-shadow: 0 0 40px rgba(255, 45, 149, 0.4), 0 20px 60px rgba(0, 0, 0, 0.5);
            animation: hueDrift 22s ease-in-out infinite;
        }

        body.cyberpunk .course-card--vibe {
            background: linear-gradient(135deg, #00f5ff 0%, #b537f2 100%);
            box-shadow: 0 0 40px rgba(0, 245, 255, 0.4), 0 20px 60px rgba(0, 0, 0, 0.5);
        }

        body.cyberpunk .course-card .course-link {
            background: rgba(10, 0, 21, 0.88);
            color: #00f5ff;
            box-shadow: 0 0 15px rgba(0, 245, 255, 0.35);
        }

        body.cyberpunk .course-card--vibe .course-link {
            color: #ff2d95;
            box-shadow: 0 0 15px rgba(255, 45, 149, 0.35);
        }

        body.cyberpunk .course-card .course-link:hover {
            box-shadow: 0 0 25px rgba(0, 245, 255, 0.6);
        }

        body.cyberpunk .course-card--vibe .course-link:hover {
            box-shadow: 0 0 25px rgba(255, 45, 149, 0.6);
        }

        /* Testimonials */
        body.cyberpunk .testimonials-content {
            background: rgba(15, 8, 38, 0.7);
            border-left-color: #00f5ff;
            box-shadow: 0 0 24px rgba(0, 245, 255, 0.2);
        }

        body.cyberpunk .testimonials-content p {
            color: #c8d3ff;
        }

        body.cyberpunk .testimonials-content strong {
            color: #00f5ff;
        }

        /* Services */
        body.cyberpunk .service-card {
            background: rgba(15, 8, 38, 0.7);
            border-left-color: #ff2d95;
            box-shadow: 0 0 20px rgba(255, 45, 149, 0.2);
        }

        body.cyberpunk .service-card:hover {
            box-shadow: 0 0 30px rgba(255, 45, 149, 0.45), 0 12px 24px rgba(0, 0, 0, 0.5);
        }

        body.cyberpunk .service-card h3 {
            color: #fff;
        }

        body.cyberpunk .service-card p {
            color: #a78bcc;
        }

        body.cyberpunk .service-subitem h4 {
            color: #00f5ff;
            text-shadow: 0 0 8px rgba(0, 245, 255, 0.4);
        }

        body.cyberpunk .service-subitem + .service-subitem {
            border-top-color: rgba(255, 45, 149, 0.2);
        }

        body.cyberpunk .service-subitem-link {
            color: #00f5ff;
            text-shadow: 0 0 8px rgba(0, 245, 255, 0.5);
        }

        body.cyberpunk .service-card .booked-badge {
            background: rgba(255, 45, 149, 0.15);
            color: #ff2d95;
            border: 1px solid rgba(255, 45, 149, 0.4);
        }

        /* About */
        body.cyberpunk .about-content p {
            color: #c8d3ff;
        }

        body.cyberpunk .about-content .highlight {
            background: linear-gradient(135deg, rgba(255, 45, 149, 0.15) 0%, rgba(0, 245, 255, 0.1) 100%);
            border-left-color: #ff2d95;
            box-shadow: 0 0 20px rgba(255, 45, 149, 0.18);
        }

        body.cyberpunk .about-content strong {
            color: #fff;
        }

        /* Contact + footer */
        body.cyberpunk .contact-section {
            background: #0a0015;
        }

        body.cyberpunk .contact-section .section-intro {
            color: #a78bcc;
        }

        body.cyberpunk .social-link {
            background: rgba(255, 45, 149, 0.1);
            border: 1px solid rgba(0, 245, 255, 0.3);
        }

        body.cyberpunk .social-link:hover {
            background: #ff2d95;
            box-shadow: 0 0 25px rgba(255, 45, 149, 0.6);
        }

        body.cyberpunk footer {
            background: #000;
            color: #5c4f7a;
        }

        /* Accessibility: honor reduced-motion preference */
        @media (prefers-reduced-motion: reduce) {
            body.cyberpunk .hero,
            body.cyberpunk .course-card {
                animation: none;
            }
            .theme-toggle,
            .theme-toggle:hover {
                transition: none;
                transform: none;
            }
        }

        /* ============================================
           Language switch
           ============================================ */
        .lang-switch {
            position: fixed;
            top: 1.5rem;
            right: 1.5rem;
            z-index: 200;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            min-width: 44px;
            height: 36px;
            padding: 0 0.85rem;
            border-radius: 20px;
            border: 1px solid rgba(16, 185, 129, 0.5);
            background: rgba(255, 255, 255, 0.85);
            color: var(--dark-green);
            font-size: 0.85rem;
            font-weight: 700;
            letter-spacing: 0.05em;
            text-decoration: none;
            backdrop-filter: blur(8px);
            -webkit-backdrop-filter: blur(8px);
            transition: transform 0.3s ease, box-shadow 0.3s ease, background 0.3s ease, color 0.3s ease;
        }

        .lang-switch:hover {
            background: var(--primary-green);
            color: #fff;
            transform: translateY(-1px);
            box-shadow: 0 6px 16px rgba(16, 185, 129, 0.3);
        }

        .lang-switch:focus-visible {
            outline: 2px solid var(--primary-green);
            outline-offset: 3px;
        }

        body.cyberpunk .lang-switch {
            border-color: #00f5ff;
            background: rgba(10, 0, 21, 0.85);
            color: #00f5ff;
            box-shadow: 0 0 12px rgba(0, 245, 255, 0.35);
        }

        body.cyberpunk .lang-switch:hover {
            background: #00f5ff;
            color: #0a0015;
            box-shadow: 0 0 22px rgba(0, 245, 255, 0.6);
        }