:root {
    --bg: #f7f8fb;
    --text: #111827;
    --muted: #6b7280;
    --primary: #111827;
    --accent: #2563eb;
    --card: #ffffff;
    --line: #e5e7eb;
    --success: #0f766e;
    --error: #b91c1c;
}
* { box-sizing: border-box; }
body { margin: 0; font-family: Arial, Helvetica, sans-serif; background: var(--bg); color: var(--text); line-height: 1.6; }
a { color: inherit; text-decoration: none; }
.site-header { position: sticky; top: 0; z-index: 20; display: flex; align-items: center; justify-content: space-between; padding: 18px 6vw; background: rgba(255,255,255,.92); backdrop-filter: blur(12px); border-bottom: 1px solid var(--line); }
.brand { font-weight: 800; font-size: 22px; letter-spacing: -.03em; }
.nav { display: flex; align-items: center; gap: 20px; color: #374151; }
.nav a:hover { color: var(--accent); }
.badge { display: inline-flex; min-width: 22px; height: 22px; align-items: center; justify-content: center; border-radius: 99px; background: var(--primary); color: white; font-size: 12px; padding: 0 6px; }
.nav-toggle { display: none; border: 1px solid var(--line); background: white; padding: 8px 12px; border-radius: 12px; }
.hero { display: grid; grid-template-columns: 1.05fr .95fr; gap: 40px; align-items: center; min-height: 680px; padding: 70px 6vw; background: radial-gradient(circle at 20% 20%, #dbeafe, transparent 36%), linear-gradient(135deg, #fff, #eef2ff); }
.hero h1 { font-size: clamp(42px, 7vw, 86px); line-height: .96; margin: 10px 0 20px; letter-spacing: -.06em; }
.hero-text { max-width: 620px; font-size: 20px; color: #374151; }
.eyebrow { text-transform: uppercase; letter-spacing: .14em; color: var(--accent); font-weight: 700; font-size: 13px; }
.hero-media { display: flex; justify-content: center; }
.hero-media img, .product-gallery img { width: min(100%, 520px); filter: drop-shadow(0 28px 50px rgba(17,24,39,.18)); }
.hero-actions, .actions-row, .upgrade-actions { display: flex; gap: 14px; flex-wrap: wrap; margin-top: 24px; }
.btn { display: inline-flex; align-items: center; justify-content: center; border-radius: 999px; padding: 12px 22px; border: 1px solid var(--line); font-weight: 700; cursor: pointer; }
.btn.primary { background: var(--primary); color: white; border-color: var(--primary); }
.btn.ghost { background: white; color: var(--primary); }
.hero-pills { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 28px; }
.hero-pills span { background: white; border: 1px solid var(--line); padding: 8px 12px; border-radius: 999px; color: #374151; }
.section { padding: 70px 6vw; }
.narrow { max-width: 1040px; margin: 0 auto; }
.feature-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.feature-grid.small { grid-template-columns: repeat(4, 1fr); }
.card, .form-card, .panel { background: var(--card); border: 1px solid var(--line); border-radius: 26px; padding: 26px; box-shadow: 0 18px 40px rgba(17,24,39,.06); }
.card h3 { margin-top: 0; }
.split, .product-detail, .checkout-grid, .upgrade-page, .admin-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 34px; align-items: start; }
.panel.dark { background: #111827; color: white; }
.big { font-size: 34px; font-weight: 800; margin: 10px 0; }
.steps { padding-left: 20px; font-size: 19px; }
.video-box { min-height: 320px; display: flex; align-items: center; justify-content: center; border-radius: 32px; background: linear-gradient(135deg, #111827, #1e3a8a); color: white; text-align: center; padding: 30px; }
.price { font-size: 34px; font-weight: 800; margin: 18px 0; }
.buy-form, .form-card { display: grid; gap: 16px; }
label { display: grid; gap: 6px; font-weight: 700; }
input, select, textarea { width: 100%; padding: 12px 14px; border: 1px solid var(--line); border-radius: 12px; font: inherit; background: white; }
textarea { min-height: 90px; }
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.spec-table, .cart-table { width: 100%; border-collapse: collapse; background: white; border-radius: 20px; overflow: hidden; }
.spec-table th, .spec-table td, .cart-table th, .cart-table td { border-bottom: 1px solid var(--line); padding: 14px; text-align: left; }
.cart-summary { display: flex; align-items: center; justify-content: space-between; gap: 20px; margin-top: 20px; flex-wrap: wrap; }
.table-wrap { overflow-x: auto; }
.notice { max-width: 1040px; margin: 18px auto; padding: 12px 16px; border-radius: 14px; background: #eef2ff; color: #1e3a8a; }
.notice.success { background: #ccfbf1; color: var(--success); }
.notice.error { background: #fee2e2; color: var(--error); }
.form-page, .auth-card-wrap { display: flex; justify-content: center; align-items: center; min-height: 70vh; }
.form-card { width: min(100%, 520px); }
.order-summary p { display: flex; justify-content: space-between; gap: 20px; }
.device-card dl { display: grid; grid-template-columns: 120px 1fr; gap: 10px; }
.device-card dt { color: var(--muted); }
.pack-list { display: grid; gap: 14px; }
.pack-row { display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 18px; background: white; border: 1px solid var(--line); border-radius: 18px; }
.bullets { color: #374151; }
.site-footer { display: flex; justify-content: space-between; gap: 20px; padding: 40px 6vw; border-top: 1px solid var(--line); background: white; color: #374151; }
.site-footer div:last-child { display: flex; gap: 18px; flex-wrap: wrap; }
.admin-body { background: #f3f4f6; }
.admin-main { padding: 30px 0; }
.admin-header { position: static; }
.muted { color: var(--muted); font-size: 14px; }
hr { border: none; border-top: 1px solid var(--line); }
@media (max-width: 900px) {
    .nav-toggle { display: inline-flex; }
    .nav { display: none; position: absolute; left: 4vw; right: 4vw; top: 70px; background: white; border: 1px solid var(--line); border-radius: 20px; padding: 18px; flex-direction: column; align-items: flex-start; box-shadow: 0 18px 40px rgba(17,24,39,.1); }
    .nav.is-open { display: flex; }
    .hero, .split, .product-detail, .checkout-grid, .upgrade-page, .admin-grid { grid-template-columns: 1fr; }
    .hero { min-height: auto; padding-top: 40px; }
    .feature-grid, .feature-grid.small { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 560px) {
    .section, .hero { padding-left: 20px; padding-right: 20px; }
    .feature-grid, .feature-grid.small, .grid-2 { grid-template-columns: 1fr; }
    .site-footer { flex-direction: column; }
    .cart-summary { align-items: flex-start; }
}
.lang-form { margin: 0; }
.lang-form select { width: auto; min-width: 118px; padding: 8px 10px; border-radius: 999px; background: white; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }
@media (max-width: 900px) { .lang-form select { width: 100%; } }