/* Trang giới thiệu G-TEK — giao diện sáng. Màu thương hiệu lấy từ logo/app
   (#1F8FD8, #4FC3F1). Không phụ thuộc framework CSS. */
:root {
  --brand: #1f8fd8;
  --brand-deep: #0b5fa5;
  --brand-2: #4fc3f1;
  --mint: #12b886;
  --gold: #f5b731;
  --ink: #0b1b2e;
  --text: #3a4a5e;
  --muted: #6b7a8f;
  --line: #e3e9f2;
  --bg: #f6f9fd;
  --card: #ffffff;
  --radius: 20px;
  --shadow: 0 1px 2px rgba(11, 27, 46, 0.04), 0 12px 32px -12px rgba(11, 27, 46, 0.14);
  --shadow-lg: 0 2px 4px rgba(11, 27, 46, 0.05), 0 30px 60px -20px rgba(16, 72, 130, 0.28);
  --grad: linear-gradient(135deg, var(--brand) 0%, var(--brand-2) 100%);
  --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
  color-scheme: light;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 84px; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: "Be Vietnam Pro", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}
img, svg, canvas { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
h1, h2, h3 { color: var(--ink); line-height: 1.15; margin: 0; letter-spacing: -0.02em; }
p { margin: 0; }
.mono { font-family: var(--mono); }
.wrap { width: min(1200px, 100% - 32px); margin-inline: auto; }

/* ---------- Nền: lưới mờ + hai mảng màu trôi chậm ---------- */
.bg-grid {
  position: fixed; inset: 0; z-index: -2; pointer-events: none;
  background-image:
    linear-gradient(rgba(31, 143, 216, 0.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(31, 143, 216, 0.06) 1px, transparent 1px);
  background-size: 44px 44px;
  mask-image: radial-gradient(ellipse at 50% 0%, #000 0%, transparent 75%);
}
.bg-blob {
  position: fixed; z-index: -1; pointer-events: none; border-radius: 50%;
  filter: blur(70px); opacity: 0.55;
  animation: blob 22s ease-in-out infinite alternate;
}
.bg-blob-a { width: 520px; height: 520px; top: -160px; right: -120px; background: #bfe6fb; }
.bg-blob-b { width: 460px; height: 460px; top: 380px; left: -180px; background: #d7f5ea; animation-delay: -8s; }
@keyframes blob {
  0% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(-40px, 60px) scale(1.08); }
  100% { transform: translate(30px, -20px) scale(0.96); }
}

/* ---------- Nút ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 13px 22px; border-radius: 999px; border: 1px solid transparent;
  font: inherit; font-weight: 600; font-size: 15px; cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
  white-space: nowrap;
}
.btn svg { width: 18px; height: 18px; }
.btn:focus-visible, .link-btn:focus-visible, .console-btn:focus-visible { outline: 3px solid rgba(31, 143, 216, 0.35); outline-offset: 2px; }
.btn-primary { background: var(--grad); color: #fff; box-shadow: 0 10px 24px -8px rgba(31, 143, 216, 0.6); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 16px 30px -10px rgba(31, 143, 216, 0.7); }
.btn-light { background: #fff; color: var(--ink); border-color: var(--line); box-shadow: var(--shadow); }
.btn-light:hover { transform: translateY(-2px); border-color: #c9d8ea; }
.btn-ghost { color: var(--ink); padding-inline: 14px; }
.btn-ghost:hover { color: var(--brand); }
.btn-sm { padding: 10px 18px; font-size: 14px; }
.btn-block { width: 100%; }

/* ---------- Header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(246, 249, 253, 0.72);
  backdrop-filter: blur(16px) saturate(160%);
  -webkit-backdrop-filter: blur(16px) saturate(160%);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s, box-shadow 0.3s;
}
.site-header.scrolled { border-color: var(--line); box-shadow: 0 8px 24px -18px rgba(11, 27, 46, 0.35); }
.header-row { display: flex; align-items: center; gap: 24px; height: 72px; }
.brand { display: flex; align-items: center; gap: 10px; }
.brand img { border-radius: 10px; box-shadow: var(--shadow); }
.brand b { display: block; color: var(--ink); font-size: 18px; font-weight: 800; letter-spacing: 0.02em; }
.brand small { display: block; color: var(--muted); font-size: 12px; margin-top: -2px; }
.brand.small b { font-size: 15px; }
.main-nav { display: flex; gap: 4px; margin-left: auto; }
.main-nav a {
  padding: 8px 14px; border-radius: 999px; font-size: 14px; font-weight: 500; color: var(--text);
  transition: background 0.2s, color 0.2s;
}
.main-nav a:hover, .main-nav a.active { background: rgba(31, 143, 216, 0.1); color: var(--brand-deep); }
.header-actions { display: flex; align-items: center; gap: 6px; }
.nav-toggle { display: none; }

/* ---------- Hero ---------- */
.hero { padding: 48px 0 40px; }
.hero-grid { display: grid; grid-template-columns: 1.02fr 1fr; gap: 40px; align-items: center; min-height: calc(100vh - 160px); }
.badge {
  display: inline-flex; align-items: center; gap: 10px;
  padding: 7px 14px; border-radius: 999px; background: #fff; border: 1px solid var(--line);
  font-size: 13px; font-weight: 600; color: var(--brand-deep); box-shadow: var(--shadow);
}
.pulse-dot {
  width: 9px; height: 9px; border-radius: 50%; background: var(--mint); flex: none;
  box-shadow: 0 0 0 0 rgba(18, 184, 134, 0.6); animation: pulse 2s infinite;
}
.pulse-dot.small { width: 7px; height: 7px; }
@keyframes pulse {
  0% { box-shadow: 0 0 0 0 rgba(18, 184, 134, 0.55); }
  70% { box-shadow: 0 0 0 10px rgba(18, 184, 134, 0); }
  100% { box-shadow: 0 0 0 0 rgba(18, 184, 134, 0); }
}
.hero h1 { font-size: clamp(34px, 4.1vw, 54px); font-weight: 800; margin: 22px 0 18px; text-wrap: balance; }
.grad-text {
  display: block;
  background: linear-gradient(100deg, var(--brand-deep), var(--brand) 45%, var(--brand-2) 70%, var(--mint));
  background-size: 200% auto;
  -webkit-background-clip: text; background-clip: text; color: transparent;
  animation: shine 8s linear infinite;
}
@keyframes shine { to { background-position: 200% center; } }
.lead { font-size: 18px; max-width: 560px; color: var(--text); }
.cta-row { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 30px; }
.stats { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 12px; margin: 36px 0 0; max-width: 560px; }
.stat {
  background: rgba(255, 255, 255, 0.8); border: 1px solid var(--line); border-radius: 16px;
  padding: 14px 16px; box-shadow: var(--shadow);
}
.stat dt { font-size: 26px; font-weight: 800; color: var(--ink); font-variant-numeric: tabular-nums; }
.stat dd { margin: 2px 0 0; font-size: 13px; color: var(--muted); line-height: 1.35; }

.hero-visual { position: relative; }
.hero-stage {
  position: relative; aspect-ratio: 1 / 1; width: 100%; max-height: 640px;
  border-radius: 32px;
  background:
    radial-gradient(circle at 50% 38%, #ffffff 0%, rgba(255, 255, 255, 0) 60%),
    radial-gradient(circle at 70% 80%, rgba(79, 195, 241, 0.22), transparent 55%),
    radial-gradient(circle at 20% 20%, rgba(31, 143, 216, 0.14), transparent 50%);
  cursor: grab; touch-action: pan-y;
}
.hero-stage:active { cursor: grabbing; }
#hero-canvas { position: absolute; inset: 0; width: 100%; height: 100%; opacity: 0; transition: opacity 0.8s ease; }
.hero-stage.ready #hero-canvas { opacity: 1; }
.hero-stage.ready .stage-fallback { opacity: 0; }
.stage-hint {
  position: absolute; right: 18px; top: 16px; font-size: 12px; color: var(--muted);
  background: rgba(255, 255, 255, 0.8); padding: 4px 10px; border-radius: 999px; border: 1px solid var(--line);
  opacity: 0; transition: opacity 0.5s;
}
.hero-stage.ready .stage-hint { opacity: 1; }
/* Ảnh dự phòng khi không có WebGL: máy vẽ bằng CSS. */
.stage-fallback { position: absolute; inset: 0; display: grid; place-items: center; transition: opacity 0.6s; }
.fb-device {
  width: 44%; aspect-ratio: 0.62; border-radius: 28px; background: linear-gradient(160deg, #fff, #e8f1fa);
  box-shadow: var(--shadow-lg); display: grid; place-items: center; transform: perspective(800px) rotateY(-18deg) rotateX(6deg);
}
.fb-screen {
  width: 76%; aspect-ratio: 0.8; border-radius: 16px; background: var(--grad); display: grid;
  grid-template-columns: 1fr 1fr; gap: 10%; padding: 16%;
}
.fb-screen i { background: rgba(255, 255, 255, 0.9); border-radius: 6px; }

.glass {
  background: rgba(255, 255, 255, 0.78);
  backdrop-filter: blur(14px) saturate(160%);
  -webkit-backdrop-filter: blur(14px) saturate(160%);
  border: 1px solid rgba(255, 255, 255, 0.9);
  box-shadow: var(--shadow-lg);
}
.board-card {
  position: absolute; left: -36px; bottom: -2%; width: min(280px, 64%);
  border-radius: 18px; padding: 16px; animation: float 7s ease-in-out infinite;
}
.board-head { display: flex; justify-content: space-between; align-items: center; font-size: 12px; color: var(--muted); }
.chip-ok {
  display: inline-flex; align-items: center; gap: 6px; font-size: 11px; font-weight: 700;
  color: #0b8a63; background: rgba(18, 184, 134, 0.12); padding: 3px 8px; border-radius: 999px;
}
.board-chip { display: flex; align-items: center; gap: 12px; margin: 12px 0; }
.board-chip svg { width: 40px; height: 40px; color: var(--brand); flex: none; }
.board-chip b { display: block; color: var(--ink); font-size: 15px; }
.board-chip small { color: var(--muted); font-size: 12px; }
.board-specs { list-style: none; margin: 0; padding: 10px 0 0; border-top: 1px dashed var(--line); display: grid; gap: 4px; }
.board-specs li { display: flex; justify-content: space-between; gap: 12px; font-size: 12px; }
.board-specs b { color: var(--ink); font-weight: 600; }
.pay-toast {
  position: absolute; right: -6px; top: 14%; display: flex; align-items: center; gap: 12px;
  padding: 12px 16px; border-radius: 16px;
  opacity: 0; transform: translateY(12px) scale(0.96); transition: opacity 0.45s ease, transform 0.45s ease;
}
.pay-toast.show { opacity: 1; transform: none; }
.pay-icon { width: 38px; height: 38px; border-radius: 12px; background: rgba(18, 184, 134, 0.14); color: #0b8a63; display: grid; place-items: center; }
.pay-icon svg { width: 22px; height: 22px; }
.pay-toast b { display: block; color: var(--ink); font-size: 16px; }
.pay-toast small { color: var(--muted); font-size: 12px; }
@keyframes float { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-10px); } }

/* ---------- Khối chung ---------- */
.section { padding: 96px 0; position: relative; }
.section-tint { background: linear-gradient(180deg, rgba(232, 242, 251, 0.7), rgba(246, 249, 253, 0)); }
.section-head { max-width: 720px; margin: 0 auto 48px; text-align: center; }
.kicker {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 13px; font-weight: 700; letter-spacing: 0.12em; text-transform: uppercase; color: var(--brand);
}
.section h2 { font-size: clamp(30px, 3.6vw, 44px); font-weight: 800; margin: 12px 0 14px; }
.section-sub { color: var(--muted); font-size: 17px; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow); }

/* ---------- Sản phẩm (thẻ nghiêng 3D) ---------- */
.product-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 22px; }
.tilt {
  position: relative; transform-style: preserve-3d;
  transform: perspective(900px) rotateX(var(--rx, 0deg)) rotateY(var(--ry, 0deg)) translateY(var(--lift, 0));
  transition: transform 0.25s ease, box-shadow 0.25s ease;
  will-change: transform;
}
.tilt:hover { --lift: -6px; box-shadow: var(--shadow-lg); }
.tilt-glare {
  position: absolute; inset: 0; border-radius: inherit; pointer-events: none; opacity: 0;
  background: radial-gradient(circle at var(--gx, 50%) var(--gy, 0%), rgba(255, 255, 255, 0.9), transparent 55%);
  mix-blend-mode: soft-light; transition: opacity 0.3s;
}
.tilt:hover .tilt-glare { opacity: 1; }
.product-card {
  background: var(--card); border: 1px solid var(--line); border-radius: 22px; box-shadow: var(--shadow);
  padding: 26px; display: flex; flex-direction: column;
}
.product-card::after {
  content: ""; position: absolute; left: 26px; right: 26px; top: 0; height: 3px; border-radius: 0 0 4px 4px;
  background: var(--grad); opacity: 0; transition: opacity 0.3s;
}
.product-card:hover::after { opacity: 1; }
.card-icon {
  width: 52px; height: 52px; border-radius: 16px; display: grid; place-items: center;
  background: linear-gradient(135deg, rgba(31, 143, 216, 0.14), rgba(79, 195, 241, 0.18));
  color: var(--brand-deep); transform: translateZ(30px);
}
.card-icon svg { width: 26px; height: 26px; }
.card-icon.alt { background: linear-gradient(135deg, rgba(18, 184, 134, 0.14), rgba(79, 195, 241, 0.16)); color: #0b8a63; }
.card-tag { margin: 18px 0 6px; font-size: 12px; font-weight: 700; letter-spacing: 0.08em; text-transform: uppercase; color: var(--brand); }
.product-card h3 { font-size: 20px; font-weight: 700; transform: translateZ(20px); }
.card-desc { margin-top: 10px; font-size: 15px; color: var(--text); }
.checks { list-style: none; padding: 0; margin: 18px 0 0; display: grid; gap: 8px; flex: 1; }
.checks li { display: flex; gap: 10px; font-size: 14px; align-items: flex-start; }
.checks svg { width: 18px; height: 18px; color: var(--mint); flex: none; margin-top: 2px; }
.link-btn {
  margin-top: 20px; align-self: flex-start; background: none; border: 0; padding: 6px 0; cursor: pointer;
  font: inherit; font-weight: 600; font-size: 14px; color: var(--brand-deep);
}
.link-btn span { display: inline-block; transition: transform 0.2s; }
.link-btn:hover span { transform: translateX(4px); }

/* ---------- Giám sát (console mô phỏng) ---------- */
.telemetry-grid { display: grid; grid-template-columns: 0.9fr 1.1fr; gap: 48px; align-items: center; }
.telemetry-copy h2 { margin-top: 10px; }
.mini-metrics { display: flex; gap: 14px; margin-top: 26px; flex-wrap: wrap; }
.mini-metrics div { background: #fff; border: 1px solid var(--line); border-radius: 16px; padding: 14px 18px; min-width: 170px; box-shadow: var(--shadow); }
.mini-metrics b { display: block; font-size: 24px; color: var(--ink); font-variant-numeric: tabular-nums; }
.mini-metrics span { font-size: 13px; color: var(--muted); }
.console { border-radius: 20px; overflow: hidden; background: #0d1b2c; box-shadow: var(--shadow-lg); border: 1px solid #1d3047; }
.console-bar { display: flex; align-items: center; gap: 12px; padding: 12px 16px; background: #122539; color: #8aa3bd; font-size: 12px; }
.dots { display: flex; gap: 6px; }
.dots i { width: 10px; height: 10px; border-radius: 50%; background: #ff6b6b; }
.dots i:nth-child(2) { background: #f5b731; }
.dots i:nth-child(3) { background: #12b886; }
.console-actions { margin-left: auto; display: flex; gap: 6px; }
.console-btn {
  background: rgba(255, 255, 255, 0.06); border: 1px solid rgba(255, 255, 255, 0.12); color: #cfe1f3;
  font: inherit; font-size: 12px; padding: 4px 10px; border-radius: 8px; cursor: pointer;
}
.console-btn:hover { background: rgba(255, 255, 255, 0.12); }
.console-body { height: 340px; overflow-y: auto; padding: 14px 16px; font-size: 12.5px; color: #d6e4f0; scroll-behavior: smooth; }
.log-row { display: grid; grid-template-columns: auto auto 1fr; gap: 10px; padding: 5px 0; border-bottom: 1px solid rgba(255, 255, 255, 0.05); animation: rowIn 0.4s ease; }
.log-row .t { color: #6f8aa6; }
.log-row .d { color: #4fc3f1; font-weight: 600; }
.log-row .e.pay { color: #4ee6b0; }
.log-row .e.coin { color: #f5c75d; }
.log-row .e.photo { color: #c4a5ff; }
.log-row .e.sys { color: #9fb3c8; }
@keyframes rowIn { from { opacity: 0; transform: translateX(-8px); } to { opacity: 1; transform: none; } }

/* ---------- Bảng tính dự toán ---------- */
.calc-grid { display: grid; grid-template-columns: 1.25fr 0.9fr; gap: 26px; align-items: start; }
.calc-form { padding: 28px; }
fieldset { border: 0; padding: 0; margin: 0 0 28px; }
fieldset:last-child { margin-bottom: 0; }
legend { display: flex; align-items: center; gap: 10px; width: 100%; font-weight: 700; color: var(--ink); margin-bottom: 14px; }
.step { width: 26px; height: 26px; border-radius: 50%; background: var(--grad); color: #fff; font-size: 13px; display: grid; place-items: center; flex: none; }
.qty-out { margin-left: auto; font-weight: 800; color: var(--brand-deep); font-variant-numeric: tabular-nums; }
.choice-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; }
.choice { position: relative; cursor: pointer; }
.choice input { position: absolute; opacity: 0; }
.choice span {
  display: block; height: 100%; padding: 14px 16px; border-radius: 14px; border: 1.5px solid var(--line); background: #fbfdff;
  transition: border-color 0.2s, box-shadow 0.2s, background 0.2s;
}
.choice b { display: block; color: var(--ink); font-size: 14px; font-weight: 600; line-height: 1.35; }
.choice small { color: var(--muted); font-size: 13px; }
.choice input:checked + span { border-color: var(--brand); background: rgba(31, 143, 216, 0.06); box-shadow: 0 0 0 4px rgba(31, 143, 216, 0.12); }
.choice input:focus-visible + span { outline: 3px solid rgba(31, 143, 216, 0.35); }
input[type="range"] { width: 100%; accent-color: var(--brand); height: 28px; }
.range-scale { display: flex; justify-content: space-between; font-size: 12px; color: var(--muted); }
.toggle-row {
  display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 14px;
  padding: 14px 16px; border: 1.5px solid var(--line); border-radius: 14px; margin-bottom: 10px; cursor: pointer;
  transition: border-color 0.2s, background 0.2s;
}
.toggle-row input { position: absolute; opacity: 0; }
.switch { width: 42px; height: 24px; border-radius: 999px; background: #d5dfeb; position: relative; transition: background 0.2s; }
.switch::after { content: ""; position: absolute; top: 3px; left: 3px; width: 18px; height: 18px; border-radius: 50%; background: #fff; box-shadow: 0 1px 3px rgba(0, 0, 0, 0.2); transition: transform 0.2s; }
.toggle-row input:checked ~ .switch { background: var(--brand); }
.toggle-row input:checked ~ .switch::after { transform: translateX(18px); }
.toggle-row:has(input:checked) { border-color: rgba(31, 143, 216, 0.45); background: rgba(31, 143, 216, 0.04); }
.toggle-row input:focus-visible ~ .switch { outline: 3px solid rgba(31, 143, 216, 0.35); outline-offset: 2px; }
.toggle-text b { display: block; color: var(--ink); font-size: 14px; font-weight: 600; }
.toggle-text small { color: var(--muted); font-size: 13px; }
.toggle-price { font-size: 13px; font-weight: 700; color: var(--brand-deep); white-space: nowrap; }
.calc-summary { position: sticky; top: 92px; }
.summary-card {
  border-radius: 24px; padding: 28px; color: #e8f3fc;
  background: radial-gradient(circle at 100% 0%, rgba(79, 195, 241, 0.35), transparent 50%), linear-gradient(160deg, #0f3a63, #0b1b2e);
  box-shadow: var(--shadow-lg);
}
.summary-head { display: flex; justify-content: space-between; align-items: center; font-weight: 700; color: #fff; }
.chip-live { font-size: 11px; font-weight: 700; color: #4ee6b0; background: rgba(78, 230, 176, 0.14); padding: 4px 10px; border-radius: 999px; }
.summary-rows { margin: 20px 0; display: grid; gap: 10px; }
.summary-rows div { display: flex; justify-content: space-between; gap: 12px; font-size: 14px; padding-bottom: 10px; border-bottom: 1px solid rgba(255, 255, 255, 0.08); }
.summary-rows dt { color: #a9c1d8; }
.summary-rows dd { margin: 0; font-weight: 600; color: #fff; font-variant-numeric: tabular-nums; }
.summary-rows dd.ok { color: #4ee6b0; }
.total-label { font-size: 12px; letter-spacing: 0.1em; text-transform: uppercase; color: #a9c1d8; }
.total { font-size: clamp(30px, 3.2vw, 40px); font-weight: 800; color: #fff; margin: 4px 0 6px; font-variant-numeric: tabular-nums; }
.fine { font-size: 12px; color: #8ea8c1; }
.roi { display: flex; gap: 12px; margin: 20px 0; padding: 14px; border-radius: 16px; background: rgba(78, 230, 176, 0.08); border: 1px solid rgba(78, 230, 176, 0.25); }
.roi svg { width: 24px; height: 24px; color: #4ee6b0; flex: none; }
.roi b { color: #fff; font-size: 14px; }
.roi p { font-size: 13px; color: #b8cde0; margin-top: 2px; }

/* ---------- Công nghệ ---------- */
.tech-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 20px; }
.tech-card { background: var(--card); border: 1px solid var(--line); border-radius: 22px; padding: 24px; box-shadow: var(--shadow); }
.tech-card h3 { font-size: 18px; margin: 18px 0 8px; }
.tech-card p { font-size: 14px; }

/* ---------- Liên hệ ---------- */
.contact-grid { display: grid; grid-template-columns: 0.9fr 1.1fr; gap: 48px; align-items: start; }
.info-list { list-style: none; padding: 0; margin: 28px 0 0; display: grid; gap: 12px; }
.info-list li { display: flex; gap: 14px; align-items: center; background: #fff; border: 1px solid var(--line); border-radius: 16px; padding: 14px 16px; box-shadow: var(--shadow); }
.info-icon { width: 42px; height: 42px; border-radius: 12px; display: grid; place-items: center; background: rgba(31, 143, 216, 0.1); color: var(--brand-deep); flex: none; }
.info-icon svg { width: 20px; height: 20px; }
.info-list small { display: block; font-size: 12px; color: var(--muted); }
.info-list a, .info-list span { color: var(--ink); font-weight: 600; }
.steps-list { list-style: none; padding: 0; margin: 28px 0 0; display: grid; gap: 12px; counter-reset: none; }
.steps-list li { display: flex; gap: 14px; align-items: flex-start; background: #fff; border: 1px solid var(--line); border-radius: 16px; padding: 16px; box-shadow: var(--shadow); }
.steps-list li > span { width: 34px; height: 34px; border-radius: 50%; background: var(--grad); color: #fff; font-weight: 800; display: grid; place-items: center; flex: none; }
.steps-list b { display: block; color: var(--ink); }
.steps-list small { color: var(--muted); font-size: 14px; }
.contact-form { padding: 28px; display: grid; gap: 14px; position: relative; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.contact-form label { display: grid; gap: 6px; font-size: 13px; font-weight: 600; color: var(--ink); }
.contact-form input, .contact-form select, .contact-form textarea {
  font: inherit; font-size: 15px; font-weight: 400; color: var(--ink); width: 100%;
  padding: 12px 14px; border-radius: 12px; border: 1.5px solid var(--line); background: #fbfdff;
  transition: border-color 0.2s, box-shadow 0.2s;
}
.contact-form input:focus, .contact-form select:focus, .contact-form textarea:focus { outline: none; border-color: var(--brand); box-shadow: 0 0 0 4px rgba(31, 143, 216, 0.12); }
.contact-form textarea { resize: vertical; min-height: 110px; }
.contact-form .invalid { border-color: #e5484d; }
.hp { position: absolute; left: -9999px; width: 1px; height: 1px; overflow: hidden; }
.form-error { color: #d93036; font-size: 14px; min-height: 1em; }
.form-success { position: absolute; inset: 0; border-radius: inherit; background: rgba(255, 255, 255, 0.96); display: grid; place-content: center; text-align: center; gap: 14px; padding: 28px; }
.form-success[hidden] { display: none; }
.success-icon { width: 64px; height: 64px; border-radius: 50%; margin: 0 auto; background: rgba(18, 184, 134, 0.14); color: var(--mint); display: grid; place-items: center; animation: pop 0.5s ease; }
.success-icon svg { width: 32px; height: 32px; }
.form-success p { color: var(--ink); font-weight: 600; max-width: 360px; }
@keyframes pop { from { transform: scale(0.6); opacity: 0; } to { transform: none; opacity: 1; } }

/* ---------- Footer ---------- */
.site-footer { border-top: 1px solid var(--line); background: #fff; padding: 28px 0; }
.footer-row { display: flex; align-items: center; gap: 24px; flex-wrap: wrap; }
.footer-badges { list-style: none; display: flex; gap: 16px; margin: 0; padding: 0; flex-wrap: wrap; font-size: 13px; color: var(--muted); }
.footer-badges li { display: inline-flex; align-items: center; gap: 8px; }
.footer-links { margin-left: auto; display: flex; gap: 18px; font-size: 14px; }
.footer-links a:hover { color: var(--brand); }

/* ---------- Hộp chi tiết sản phẩm ---------- */
.product-modal {
  width: min(560px, calc(100% - 32px)); border: 0; border-radius: 24px; padding: 30px; color: var(--text);
  box-shadow: 0 40px 80px -20px rgba(11, 27, 46, 0.45);
}
.product-modal::backdrop { background: rgba(11, 27, 46, 0.45); backdrop-filter: blur(4px); }
.product-modal[open] { animation: modalIn 0.3s ease; }
@keyframes modalIn { from { opacity: 0; transform: translateY(16px) scale(0.98); } to { opacity: 1; transform: none; } }
.product-modal h3 { font-size: 24px; margin: 4px 0 10px; }
.product-modal .card-tag { margin-top: 0; }
.modal-close { position: absolute; right: 16px; top: 12px; width: 36px; height: 36px; border-radius: 50%; border: 0; background: #eef3f9; font-size: 22px; cursor: pointer; color: var(--ink); }
.spec-list { margin: 18px 0; padding: 0; list-style: none; display: grid; gap: 8px; }
.spec-list li { padding: 10px 14px; border-radius: 12px; background: #f3f7fc; font-size: 14px; }
.benefit { padding: 14px; border-radius: 14px; background: rgba(18, 184, 134, 0.1); color: #0b6e50; font-weight: 600; font-size: 14px; margin-bottom: 20px; }

/* ---------- Hiện dần khi cuộn ---------- */
/* Chỉ ẩn khi JS đã chạy (landing.js gắn class "js") — JS lỗi thì nội dung vẫn hiện. */
.js [data-reveal] { opacity: 0; transform: translateY(26px); transition: opacity 0.7s ease, transform 0.7s cubic-bezier(0.2, 0.7, 0.2, 1); transition-delay: calc(var(--i, 0) * 70ms); }
.js [data-reveal].in { opacity: 1; transform: none; }
.js .tilt[data-reveal].in { transform: perspective(900px) rotateX(var(--rx, 0deg)) rotateY(var(--ry, 0deg)) translateY(var(--lift, 0)); transition-delay: 0s; }
/* Phần đầu trang: hiệu ứng CSS thuần, không chờ JS. */
.enter { animation: enter 0.8s cubic-bezier(0.2, 0.7, 0.2, 1) both; animation-delay: calc(var(--d, 0) * 110ms); }
@keyframes enter { from { opacity: 0; transform: translateY(22px); } to { opacity: 1; transform: none; } }

/* ---------- Màn nhỏ ---------- */
@media (max-width: 1080px) {
  .tech-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .product-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 960px) {
  .hero-grid, .telemetry-grid, .calc-grid, .contact-grid { grid-template-columns: 1fr; }
  .hero-grid { min-height: 0; }
  .hero-visual { max-width: 560px; margin-inline: auto; width: 100%; }
  .board-card { left: 0; }
  .pay-toast { right: 0; }
  .calc-summary { position: static; }
  .main-nav {
    position: fixed; inset: 72px 0 auto 0; flex-direction: column; gap: 2px; padding: 12px 16px 18px;
    background: rgba(255, 255, 255, 0.97); border-bottom: 1px solid var(--line); box-shadow: 0 20px 30px -20px rgba(11, 27, 46, 0.3);
    transform: translateY(-120%); transition: transform 0.3s ease; margin: 0;
  }
  .main-nav.open { transform: none; }
  .main-nav a { padding: 12px 14px; font-size: 16px; }
  .nav-toggle {
    display: inline-grid; gap: 4px; width: 44px; height: 44px; place-content: center; border: 0; background: none; cursor: pointer;
  }
  .nav-toggle span { width: 20px; height: 2px; background: var(--ink); border-radius: 2px; transition: transform 0.25s, opacity 0.25s; }
  .nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(6px) rotate(45deg); }
  .nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
  .nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }
  .header-actions { margin-left: auto; }
}
@media (max-width: 640px) {
  .section { padding: 64px 0; }
  .hero { padding-top: 24px; }
  .lead { font-size: 16px; }
  .stats { grid-template-columns: 1fr 1fr 1fr; gap: 8px; }
  .stat { padding: 10px; }
  .stat dt { font-size: 19px; }
  .stat dd { font-size: 11.5px; }
  .product-grid, .tech-grid, .choice-grid, .form-row { grid-template-columns: 1fr; }
  .header-actions .btn-primary { display: none; }
  .site-header .brand small { display: none; }
  .header-row { gap: 12px; }
  .board-card { position: relative; left: auto; bottom: auto; width: 100%; margin-top: -40px; }
  .pay-toast { top: 8px; right: 8px; }
  .console-body { height: 280px; }
  .log-row { grid-template-columns: 1fr; gap: 0; }
  .footer-links { margin-left: 0; }
  .calc-form, .contact-form, .summary-card { padding: 20px; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; scroll-behavior: auto !important; }
  .js [data-reveal] { opacity: 1; transform: none; }
}