/* -- Reset & tokens ---------------------------------------- */
    *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
    :root {
      --blue-dark:   #003D7A;
      --blue:        #0066CC;
      --blue-light:  #60B5FF;
      --blue-pale:   rgba(0,102,204,.06);
      --blue-glass:  rgba(0,102,204,.12);
      --white:       #ffffff;
      --bg:          #f4f8fd;
      --text:        #1a2a3a;
      --muted:       #6b7d90;
      --border:      #d6e3f0;
      --radius:      12px;
      --radius-lg:   18px;
      --shadow-sm:   0 1px 3px rgba(0,61,122,.08);
      --shadow-md:   0 4px 12px rgba(0,61,122,.10);
      --shadow-lg:   0 10px 28px rgba(0,61,122,.12);
      --font-sans:   'DM Sans', system-ui, sans-serif;
      --font-disp:   'Plus Jakarta Sans', system-ui, sans-serif;
      --font-mono:   'JetBrains Mono', monospace;
    }
    html { scroll-behavior: smooth; }
    body {
      font-family: var(--font-sans);
      color: var(--text);
      background: var(--white);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    img { max-width: 100%; display: block; }
    a { color: inherit; text-decoration: none; }
    button { cursor: pointer; font-family: inherit; border: none; background: none; }

    /* -- Layout helpers ---------------------------------------- */
    .container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }
    .section { padding: 80px 0; }
    .section--alt { background: var(--bg); }
    .section-center { text-align: center; }
    .section-icon {
      width: 48px; height: 48px;
      background: var(--blue-glass);
      border-radius: var(--radius);
      display: flex; align-items: center; justify-content: center;
      margin: 0 auto 16px;
    }
    .section-icon svg { width: 26px; height: 26px; color: var(--blue); }
    .section-tag {
      display: inline-block;
      font-size: .75rem; font-weight: 600; letter-spacing: .08em;
      color: var(--blue); text-transform: uppercase;
      margin-bottom: 8px;
    }
    h2.section-title {
      font-family: var(--font-disp);
      font-size: clamp(1.6rem, 3vw, 2.3rem);
      font-weight: 700; letter-spacing: -.02em;
      color: var(--blue-dark); margin-bottom: 16px;
    }
    h3.sub-title {
      font-family: var(--font-disp);
      font-size: clamp(1.2rem, 2.2vw, 1.7rem);
      font-weight: 700; letter-spacing: -.02em;
      color: var(--blue-dark); margin-bottom: 14px;
    }
    .section-desc { color: var(--muted); max-width: 640px; margin: 0 auto 40px; }

    /* -- Buttons ----------------------------------------------- */
    .btn {
      display: inline-flex; align-items: center; gap: 8px;
      padding: 12px 24px; border-radius: var(--radius);
      font-weight: 600; font-size: .95rem;
      transition: all .2s;
    }
    .btn-primary {
      background: var(--blue); color: var(--white);
      box-shadow: 0 4px 14px rgba(0,102,204,.35);
    }
    .btn-primary:hover { background: #0055AA; }
    .btn-ghost {
      background: rgba(255,255,255,.12); color: var(--white);
      border: 1px solid rgba(255,255,255,.25);
    }
    .btn-ghost:hover { background: rgba(255,255,255,.22); }

    /* -- Header ------------------------------------------------ */
    header {
      position: fixed; inset: 0 0 auto 0; z-index: 100;
      transition: all .3s;
    }
    header.scrolled {
      background: rgba(255,255,255,.93);
      backdrop-filter: blur(12px);
      box-shadow: var(--shadow-sm);
    }
    .header-inner {
      display: flex; align-items: center; justify-content: space-between;
      height: 64px;
    }
    .logo {
      display: flex; align-items: center; gap: 10px;
    }
    .logo-icon {
      width: 36px; height: 36px;
      background: var(--blue); border-radius: 10px;
      display: flex; align-items: center; justify-content: center;
      flex-shrink: 0;
    }
    .logo-icon svg { width: 20px; height: 20px; color: var(--white); }
    .logo-text {
      font-family: var(--font-disp);
      font-size: 1.1rem; font-weight: 700; letter-spacing: -.01em;
      color: var(--white); transition: color .3s;
    }
    header.scrolled .logo-text { color: var(--blue-dark); }
    nav { display: flex; align-items: center; gap: 4px; }
    nav a {
      padding: 7px 14px; border-radius: 9px;
      font-size: .87rem; font-weight: 500;
      color: rgba(255,255,255,.9); transition: all .2s;
    }
    nav a:hover { color: var(--white); background: rgba(255,255,255,.12); }
    header.scrolled nav a { color: var(--blue-dark); }
    header.scrolled nav a:hover { background: var(--blue-glass); }
    .lang-btn {
      display: flex; align-items: center; gap: 6px;
      padding: 7px 14px; border-radius: 9px;
      font-size: .87rem; font-weight: 600;
      border: 1px solid rgba(255,255,255,.3); color: rgba(255,255,255,.9);
      margin-left: 8px; transition: all .2s;
    }
    .lang-btn:hover { background: rgba(255,255,255,.12); }
    header.scrolled .lang-btn {
      color: var(--blue-dark);
      border-color: rgba(0,61,122,.2);
    }
    header.scrolled .lang-btn:hover { background: var(--blue-glass); }
    .mobile-btn {
      display: none; padding: 8px; border-radius: 8px;
      color: var(--white); transition: all .2s;
    }
    header.scrolled .mobile-btn { color: var(--blue-dark); }
    .mobile-btn svg { width: 22px; height: 22px; }
    .mobile-menu {
      display: none; flex-direction: column; gap: 4px;
      background: var(--white); border-top: 1px solid var(--border);
      padding: 12px 24px;
    }
    .mobile-menu.open { display: flex; }
    .mobile-menu a {
      padding: 10px 14px; border-radius: 9px;
      font-size: .9rem; font-weight: 500; color: var(--blue-dark);
      transition: background .2s;
    }
    .mobile-menu a:hover { background: var(--blue-pale); }

    /* -- Hero -------------------------------------------------- */
    #hero {
      position: relative; min-height: 100vh;
      display: flex; align-items: center; justify-content: center;
      overflow: hidden;
    }
    .hero-bg {
      position: absolute; inset: 0;
      background-image: url('https://thumbs.dreamstime.com/b/solar-panel-photovoltaic-installation-roof-factory-sunny-blue-sky-background-alternative-electricity-source-sustainable-447709814.jpg');
      background-size: cover; background-position: center;
    }
    .hero-overlay {
      position: absolute; inset: 0;
      background: linear-gradient(to bottom, rgba(0,61,122,.82), rgba(0,61,122,.62), rgba(0,61,122,.92));
    }
    .hero-content {
      position: relative; z-index: 1;
      text-align: center; padding: 128px 24px 80px;
      max-width: 820px; margin: 0 auto;
    }
    .hero-badge {
      display: inline-block;
      padding: 6px 18px; border-radius: 999px;
      background: rgba(0,102,204,.3); border: 1px solid rgba(0,102,204,.4);
      color: var(--blue-light); font-size: .82rem; font-weight: 600;
      letter-spacing: .06em; margin-bottom: 24px;
    }
    h1.hero-title {
      font-family: var(--font-disp);
      font-size: clamp(2.2rem, 5vw, 4rem);
      font-weight: 800; letter-spacing: -.03em;
      color: var(--white); margin-bottom: 12px;
    }
    .hero-subtitle {
      font-family: var(--font-disp);
      font-size: clamp(1.2rem, 2.8vw, 2rem);
      font-weight: 700; color: var(--blue-light);
      letter-spacing: -.02em; margin-bottom: 20px;
    }
    .hero-desc {
      color: rgba(255,255,255,.82); font-size: clamp(.95rem, 1.6vw, 1.1rem);
      max-width: 600px; margin: 0 auto 40px; line-height: 1.7;
    }
    .hero-ctas { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }
    .scroll-chevron {
      position: absolute; bottom: 32px; left: 50%; transform: translateX(-50%);
      color: rgba(255,255,255,.45); animation: bounce 2s infinite;
    }
    .scroll-chevron svg { width: 28px; height: 28px; }
    @keyframes bounce { 0%,100%{transform:translateX(-50%) translateY(0)} 50%{transform:translateX(-50%) translateY(8px)} }

    /* -- Stats bar --------------------------------------------- */
    #stats { background: var(--blue-dark); padding: 36px 0; }
    .stats-grid {
      display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px;
      text-align: center;
    }
    .stat-value {
      font-family: var(--font-mono);
      font-size: clamp(1.6rem, 3vw, 2.2rem); font-weight: 700;
      color: var(--blue-light);
    }
    .stat-label { color: rgba(255,255,255,.65); font-size: .85rem; margin-top: 4px; }

    /* -- Feature cards ----------------------------------------- */
    .features-grid {
      display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px;
    }
    .feat-card {
      background: var(--white); border-radius: var(--radius);
      padding: 24px; box-shadow: var(--shadow-sm);
      transition: box-shadow .25s, transform .25s;
    }
    .feat-card:hover { box-shadow: var(--shadow-md); transform: translateY(-3px); }
    .feat-icon {
      width: 44px; height: 44px; border-radius: 12px;
      background: var(--blue-glass);
      display: flex; align-items: center; justify-content: center; margin-bottom: 16px;
      transition: background .25s;
    }
    .feat-card:hover .feat-icon { background: rgba(0,102,204,.2); }
    .feat-icon svg { width: 22px; height: 22px; color: var(--blue); }
    .feat-title {
      font-family: var(--font-disp); font-weight: 700;
      color: var(--blue-dark); font-size: 1rem; margin-bottom: 8px;
    }
    .feat-desc { color: var(--muted); font-size: .87rem; line-height: 1.65; }

    /* -- Bar charts (vanilla SVG) ------------------------------ */
    .chart-wrap {
      background: var(--white); border-radius: var(--radius);
      padding: 28px 24px; box-shadow: var(--shadow-sm);
    }
    .bar-chart { width: 100%; }
    .bar-row { display: flex; align-items: center; gap: 14px; margin-bottom: 14px; }
    .bar-row:last-child { margin-bottom: 0; }
    .bar-label {
      font-size: .83rem; color: var(--text); min-width: 160px; flex-shrink: 0;
      line-height: 1.3;
    }
    .bar-track {
      flex: 1; height: 28px; background: #edf2f7; border-radius: 6px; overflow: hidden;
      position: relative;
    }
    .bar-fill {
      height: 100%; border-radius: 6px; width: 0;
      transition: width 1.2s cubic-bezier(.22,.61,.36,1);
      display: flex; align-items: center; justify-content: flex-end;
      padding-right: 8px;
    }
    .bar-val {
      font-family: var(--font-mono); font-size: .78rem; font-weight: 700;
      color: var(--white); white-space: nowrap;
    }
    .chart-xlabel {
      text-align: center; font-size: .78rem; color: var(--muted);
      margin-top: 10px;
    }

    /* -- Layer diagram ----------------------------------------- */
    .layer-stack { max-width: 480px; margin: 0 auto; }
    .layer-item {
      display: flex; align-items: center; gap: 14px;
      padding: 12px 18px; border-radius: 10px; border: 1px solid;
      margin-bottom: 8px; opacity: 0; transform: translateX(-24px);
      transition: opacity .4s, transform .4s;
    }
    .layer-item.visible { opacity: 1; transform: translateX(0); }
    .layer-1 { background: #dbeafe; border-color: #93c5fd; }
    .layer-2 { background: #e5e7eb; border-color: #9ca3af; }
    .layer-3 { background: #fef3c7; border-color: #fbbf24; }
    .layer-4 { background: #d1fae5; border-color: #6ee7b7; }
    .layer-5 { background: #fef3c7; border-color: #fbbf24; }
    .layer-6 { background: #eff6ff; border-color: #bfdbfe; }
    .layer-7 { background: #e5e7eb; border-color: #6b7280; }
    .layer-num {
      font-family: var(--font-mono); font-size: .7rem; color: var(--muted);
      display: block; line-height: 1;
    }
    .layer-name { font-size: .9rem; font-weight: 600; color: var(--blue-dark); }
    .layer-emoji { font-size: 1.2rem; width: 28px; text-align: center; flex-shrink: 0; }

    /* -- VS boxes ---------------------------------------------- */
    .vs-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
    .vs-box { border-radius: var(--radius); padding: 28px; }
    .vs-box--gray {
      background: #f8fafc; border: 1px solid #e2e8f0;
    }
    .vs-box--blue {
      background: rgba(0,102,204,.05); border: 1px solid rgba(0,102,204,.2);
    }
    .vs-dot {
      width: 12px; height: 12px; border-radius: 50%; flex-shrink: 0;
    }
    .vs-header { display: flex; align-items: center; gap: 10px; margin-bottom: 14px; }
    .vs-header h4 {
      font-family: var(--font-disp); font-weight: 700; font-size: 1.05rem;
    }
    .vs-box--gray .vs-header h4 { color: #64748b; }
    .vs-box--blue .vs-header h4 { color: var(--blue-dark); }
    .vs-eff {
      margin-top: 14px;
      font-family: var(--font-mono); font-size: 1.6rem; font-weight: 700;
    }
    .vs-box--gray .vs-eff { color: #94a3b8; }
    .vs-box--blue .vs-eff { color: var(--blue); }
    .vs-eff-label { font-family: var(--font-sans); font-size: .82rem; color: var(--muted); margin-left: 6px; }

    /* -- Principle cards --------------------------------------- */
    .principles-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; max-width: 880px; margin: 0 auto; }
    .principle-card {
      background: var(--white); border-radius: var(--radius);
      padding: 24px; box-shadow: var(--shadow-sm);
      transition: box-shadow .25s;
    }
    .principle-card:hover { box-shadow: var(--shadow-md); }

    /* -- Comparison table -------------------------------------- */
    .comp-table-wrap {
      background: var(--white); border-radius: var(--radius);
      border: 1px solid var(--border); overflow: hidden;
      box-shadow: var(--shadow-sm);
    }
    table { width: 100%; border-collapse: collapse; font-size: .87rem; }
    thead tr { background: var(--blue-dark); color: var(--white); }
    thead th { padding: 14px 16px; font-weight: 600; text-align: left; white-space: nowrap; }
    tbody tr { border-top: 1px solid var(--border); }
    tbody tr.highlight { background: rgba(0,102,204,.05); }
    tbody td { padding: 12px 16px; color: var(--muted); }
    tbody td.td-name { font-weight: 600; color: var(--blue-dark); }
    tbody td.td-name.sm-blue { color: var(--blue); }
    tbody td.td-mono { font-family: var(--font-mono); }

    /* -- Product cards ----------------------------------------- */
    .products-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 28px; max-width: 880px; margin: 0 auto; }
    .product-card {
      border-radius: 18px; overflow: hidden;
      box-shadow: var(--shadow-sm); background: var(--white);
      transition: box-shadow .3s, transform .3s;
    }
    .product-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-4px); }
    .product-card--pro { border: 2px solid var(--blue); }
    .product-card--lite { border: 1px solid var(--border); }
    .product-badge {
      text-align: center; padding: 9px 0;
      font-size: .85rem; font-weight: 700;
    }
    .product-badge--pro { background: var(--blue); color: var(--white); }
    .product-badge--lite { background: #f1f5f9; color: var(--blue-dark); }
    .product-img {
      background: #f8fafc; padding: 28px;
      display: flex; align-items: center; justify-content: center;
      aspect-ratio: 1;
    }
    .product-img img { max-height: 220px; object-fit: contain; }
    .product-body { padding: 24px; }
    .product-name {
      font-family: var(--font-disp); font-size: 1.4rem; font-weight: 700;
      color: var(--blue-dark); margin-bottom: 18px;
    }
    .metrics-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; margin-bottom: 20px; }
    .metric {
      background: #f8fafc; border-radius: 10px;
      padding: 12px; text-align: center;
    }
    .metric-label { font-size: .72rem; color: var(--muted); margin-bottom: 3px; }
    .metric-value { font-family: var(--font-mono); font-weight: 700; color: var(--blue); font-size: 1rem; }
    .metric-value--dark { color: var(--blue-dark); }
    .spec-list { list-style: none; margin-bottom: 22px; }
    .spec-list li {
      display: flex; gap: 8px; font-size: .85rem;
      padding: 4px 0; border-bottom: 1px solid #f0f4f8;
    }
    .spec-list li:last-child { border-bottom: none; }
    .spec-check { color: var(--blue); flex-shrink: 0; margin-top: 1px; }
    .spec-key { font-weight: 600; color: var(--blue-dark); }
    .spec-val { color: var(--muted); }
    .btn-quote {
      width: 100%; display: flex; align-items: center; justify-content: center; gap: 8px;
      padding: 13px; border-radius: var(--radius);
      font-weight: 700; font-size: .95rem; transition: background .2s;
    }
    .btn-quote--pro { background: var(--blue); color: var(--white); }
    .btn-quote--pro:hover { background: #0055AA; }
    .btn-quote--lite { background: var(--blue-dark); color: var(--white); }
    .btn-quote--lite:hover { background: #002d5c; }
    .btn-quote svg { width: 16px; height: 16px; flex-shrink: 0; }
    .disclaimer {
      display: flex; gap: 12px; align-items: flex-start;
      background: #fffbeb; border: 1px solid #fde68a;
      border-radius: var(--radius); padding: 14px 16px;
      margin-top: 28px; max-width: 880px; margin-left: auto; margin-right: auto;
    }
    .disclaimer svg { color: #d97706; flex-shrink: 0; margin-top: 2px; width: 18px; height: 18px; }
    .disclaimer p { font-size: .82rem; color: #92400e; line-height: 1.5; }

    /* -- Currency selector ------------------------------------- */
    .currency-wrap { display: flex; align-items: center; justify-content: center; gap: 12px; margin-bottom: 36px; }
    .currency-label { font-size: .85rem; color: var(--muted); display: flex; align-items: center; gap: 5px; }
    .currency-label svg { width: 16px; height: 16px; color: var(--blue); }
    .currency-btns {
      display: flex; border: 1px solid var(--border); border-radius: var(--radius);
      overflow: hidden; background: var(--white);
    }
    .currency-btns button {
      padding: 6px 14px; font-size: .82rem; font-weight: 600; transition: all .15s;
      color: var(--blue-dark);
    }
    .currency-btns button.active { background: var(--blue); color: var(--white); }
    .currency-btns button:hover:not(.active) { background: var(--blue-pale); }

    /* -- About ------------------------------------------------- */
    .about-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: center; }
    .about-img { aspect-ratio: 16/9; border-radius: var(--radius-lg); overflow: hidden; background: #e5e7eb; }
    .about-img img { width: 100%; height: 100%; object-fit: cover; }

    /* -- PDF block --------------------------------------------- */
    .pdf-block {
      max-width: 680px; margin: 40px auto 0;
      background: rgba(0,102,204,.05); border: 1px solid rgba(0,102,204,.2);
      border-radius: var(--radius-lg); padding: 24px 28px;
      display: flex; align-items: center; gap: 20px; flex-wrap: wrap;
    }
    .pdf-icon {
      width: 48px; height: 48px; background: var(--blue-glass); border-radius: 12px;
      display: flex; align-items: center; justify-content: center; flex-shrink: 0;
    }
    .pdf-icon svg { width: 24px; height: 24px; color: var(--blue); }
    .pdf-info { flex: 1; min-width: 200px; }
    .pdf-info h4 { font-family: var(--font-disp); font-weight: 700; color: var(--blue-dark); margin-bottom: 4px; }
    .pdf-info p { font-size: .83rem; color: var(--muted); }
    .btn-dl {
      display: inline-flex; align-items: center; gap: 7px;
      padding: 10px 18px; border-radius: var(--radius);
      background: var(--blue); color: var(--white);
      font-size: .85rem; font-weight: 700; transition: background .2s; flex-shrink: 0;
    }
    .btn-dl:hover { background: #0055AA; }
    .btn-dl svg { width: 16px; height: 16px; }
    .table-note {
      font-size: .77rem; color: var(--muted);
      text-align: center; margin-top: 10px; max-width: 680px; margin-left: auto; margin-right: auto;
    }

    /* -- FAQ --------------------------------------------------- */
    .faq-list { max-width: 720px; margin: 0 auto; }
    .faq-item {
      background: var(--white); border-radius: var(--radius);
      box-shadow: var(--shadow-sm); overflow: hidden; margin-bottom: 10px;
      transition: box-shadow .25s;
    }
    .faq-item:hover { box-shadow: var(--shadow-md); }
    .faq-q {
      width: 100%; display: flex; align-items: center; justify-content: space-between;
      padding: 18px 20px; text-align: left;
      font-weight: 600; color: var(--blue-dark); font-size: .95rem;
    }
    .faq-chevron {
      width: 20px; height: 20px; color: var(--blue); flex-shrink: 0;
      transition: transform .25s;
    }
    .faq-item.open .faq-chevron { transform: rotate(180deg); }
    .faq-a {
      max-height: 0; overflow: hidden;
      transition: max-height .35s ease, padding .25s;
      font-size: .87rem; color: var(--muted); line-height: 1.7;
    }
    .faq-item.open .faq-a { max-height: 400px; padding: 0 20px 18px; }

    /* -- Footer ------------------------------------------------ */
    footer { background: var(--blue-dark); color: var(--white); padding: 60px 0 28px; }
    .footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: 36px; margin-bottom: 40px; }
    .footer-brand { display: flex; align-items: center; gap: 10px; margin-bottom: 14px; }
    .footer-brand svg { width: 16px; height: 16px; color: var(--white); }
    .footer-brand span { font-family: var(--font-disp); font-weight: 700; font-size: 1.05rem; }
    .footer-tagline { color: rgba(255,255,255,.6); font-size: .85rem; line-height: 1.6; }
    .footer-col h4 {
      font-family: var(--font-disp); font-weight: 600; font-size: .95rem;
      margin-bottom: 14px;
    }
    .footer-col a {
      display: block; color: rgba(255,255,255,.65);
      font-size: .85rem; margin-bottom: 8px; transition: color .2s;
    }
    .footer-col a:hover { color: var(--white); }
    .footer-contact { color: rgba(255,255,255,.65); font-size: .85rem; line-height: 1.8; }
    .footer-contact .mail-row { display: flex; align-items: center; gap: 8px; }
    .footer-contact .mail-row svg { width: 15px; height: 15px; }
    .footer-divider { border: none; border-top: 1px solid rgba(255,255,255,.15); margin-bottom: 18px; }
    .footer-copy { text-align: center; color: rgba(255,255,255,.4); font-size: .78rem; }

    /* -- Responsive -------------------------------------------- */
    @media (max-width: 900px) {
      .features-grid { grid-template-columns: 1fr 1fr; }
      .vs-grid { grid-template-columns: 1fr; }
      .principles-grid { grid-template-columns: 1fr; max-width: 560px; }
      .products-grid { grid-template-columns: 1fr; max-width: 480px; }
      .about-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
      .pdf-block { flex-direction: column; text-align: center; align-items: center; }
      .bar-label { min-width: 110px; font-size: .78rem; }
    }
    @media (max-width: 680px) {
      .container { padding: 0 16px; }
      .section { padding: 56px 0; }
      nav, .lang-btn { display: none !important; }
      .mobile-btn { display: flex !important; }
      .stats-grid { grid-template-columns: 1fr 1fr; }
      .features-grid { grid-template-columns: 1fr; }
      .vs-grid { grid-template-columns: 1fr; }
      .comp-table-wrap { font-size: .78rem; }
      thead th, tbody td { padding: 10px 10px; }
      .footer-grid { grid-template-columns: 1fr; }
      .bar-label { min-width: 90px; font-size: .74rem; }
    }
    @media (min-width: 901px) {
      .mobile-btn { display: none !important; }
      .mobile-menu { display: none !important; }
    }