:root {
  --brand: #0ea5e9;
  --brand-2: #0284c7;
  --txt: #0f172a;
  --muted: #64748b;
  --bg: #f7fbff;
  --footer: #0b1220;
  --border: #e5e7eb;
}

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

html,
body {
  height: 100%
}

body {
  font-family: Inter, system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  background: var(--bg);
  color: var(--txt)
}

img {
  display: block;
  max-width: 100%
}

a {
  text-decoration: none;
  color: inherit
}

.container {
  width: min(1200px, 92vw);
  margin: auto
}

/* Top header */
.top-header-wrap {
  background: #fff;
  border-bottom: 1px solid var(--border);
  position: relative;
  z-index: 60;
}

.top-header-wrap .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 0
}

.logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 800;
  color: var(--brand-2)
}

.logo-mark {
  height: 28px;
  width: 28px;
  border-radius: 8px
}

.top-header-menu {
  display: flex;
  align-items: center;
  gap: 16px;
  font-size: 14px;
  color: #475569
}

.top-header-menu a {
  padding: 6px 8px;
  border-radius: 8px
}

.top-header-menu a:hover {
  background: rgba(14, 165, 233, .08);
  color: var(--brand-2)
}

.notifications {
  position: relative
}

.notifications-length {
  position: absolute;
  top: -6px;
  right: -6px;
  background: #ef4444;
  color: #fff;
  font-size: 10px;
  padding: 1px 6px;
  border-radius: 10px
}

.dropdown-menu {
  position: absolute;
  right: 0;
  top: 110%;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 12px;
  min-width: 320px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, .15);
  display: none;
  z-index: 100;
  overflow: hidden
}

.dropdown-menu.show {
  display: block
}

.dropdown-header {
  padding: 12px 14px;
  border-bottom: 1px solid var(--border);
  font-weight: 700
}

.notifications-item a {
  display: block;
  padding: 12px 14px;
  color: #334155
}

.notifications-item a:hover {
  background: #f9fafb
}

/* Header / Nav */
header {
  position: sticky;
  top: 0;
  background: rgba(255, 255, 255, .92);
  backdrop-filter: saturate(160%) blur(10px);
  border-bottom: 1px solid rgba(0, 0, 0, .08);
  z-index: 50;
  transition: background .25s, box-shadow .25s
}

header.scrolled {
  background: rgba(255, 255, 255, .85);
  box-shadow: 0 6px 24px rgba(0, 0, 0, .08)
}

.nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 0
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  color: var(--brand-2)
}

.menu {
  display: flex;
  gap: 18px;
  align-items: center
}

.menu a {
  padding: 10px 12px;
  border-radius: 12px;
  color: var(--brand-2);
  font-weight: 600
}

.menu a:hover {
  background: rgba(14, 165, 233, .1)
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 10px
}

.cta {
  background: linear-gradient(90deg, var(--brand-2), var(--brand));
  color: #fff;
  border: none;
  border-radius: 12px;
  padding: 10px 16px;
  font-weight: 800;
  cursor: pointer;
  box-shadow: 0 6px 18px rgba(2, 132, 199, .25)
}

.ghost {
  border: 1px solid var(--brand-2);
  color: var(--brand-2);
  border-radius: 12px;
  padding: 10px 16px;
  font-weight: 800
}

/* Lang btn (Simple style) */
.lang-wrap {
  position: relative
}

.lang-btn {
  display: flex;
  align-items: center;
  gap: 8px;
  border: 1px solid var(--brand-2);
  color: var(--brand-2);
  background: #fff;
  border-radius: 12px;
  padding: 8px 12px;
  font-weight: 700;
  cursor: pointer
}

.lang-dd {
  position: absolute;
  right: 0;
  top: 110%;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 10px;
  display: none;
  min-width: 120px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, .15);
  z-index: 100;
}

.lang-dd.show {
  display: block
}

.lang-dd button {
  display: block;
  width: 100%;
  text-align: left;
  padding: 10px 12px;
  border: 0;
  background: #fff;
  cursor: pointer
}

.lang-dd button:hover {
  background: #f3f4f6
}

/* Hero */
.hero {
  position: relative;
  isolation: isolate
}

.hero-bg {
  position: absolute;
  inset: 0;
  z-index: -1;
  background: linear-gradient(180deg, #041d31 0%, #063d5c 40%, #f7fbff 90%)
}

.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(4, 29, 49, .65), rgba(4, 29, 49, .35) 40%, rgba(247, 251, 255, .95) 80%);
  z-index: -1
}

.hero-inner {
  padding: 42px 0 26px;
  color: #fff;
  text-align: left
}

.pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(255, 255, 255, .14);
  border: 1px solid rgba(255, 255, 255, .25);
  padding: 6px 10px;
  border-radius: 999px;
  font-weight: 700;
  margin-bottom: 12px
}

.hero h1 {
  font-size: 42px;
  line-height: 1.1;
  margin-bottom: 10px;
  text-shadow: 0 10px 30px rgba(0, 0, 0, .35)
}

.hero .lead {
  color: #e6f6ff;
  max-width: 780px;
  margin-bottom: 16px
}

.hero-actions {
  display: flex;
  gap: 10px
}

/* Stats */
.hero-stats {
  display: flex;
  gap: 24px;
  margin-top: 16px;
  flex-wrap: wrap
}

.hero-stats div {
  background: rgba(255, 255, 255, .22);
  border: 1px solid rgba(255, 255, 255, .32);
  padding: 10px 14px;
  border-radius: 12px;
  color: #0b3045;
}

.hero-stats strong {
  display: block;
  font-size: 22px;
  color: #0b3045
}

.hero-stats span {
  font-size: 14px;
  color: #094063
}

/* Sections */
.section {
  padding: 56px 0
}

.section-title {
  font-size: 28px;
  margin-bottom: 16px;
  color: #0b3045
}

.lead {
  color: var(--brand-2)
}

.fade-up {
  opacity: 0;
  transform: translateY(16px);
  transition: all .45s
}

.appear {
  opacity: 1;
  transform: none
}

/* Features */
.features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px
}

.card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 18px;
  box-shadow: 0 10px 30px rgba(2, 132, 199, .08)
}

.card .icon {
  width: 42px;
  height: 42px;
  border-radius: 12px;
  background: linear-gradient(135deg, #e0f3ff, #f0fbff);
  display: grid;
  place-items: center;
  color: var(--brand-2);
  margin-bottom: 10px
}

.card h3 {
  margin-bottom: 6px
}

/* Use cases */
.grid-2 {
  display: grid;
  grid-template-columns: 1.1fr .9fr;
  gap: 22px
}

@media (max-width:900px) {
  .grid-2 {
    grid-template-columns: 1fr
  }
}

.checklist {
  display: grid;
  gap: 8px;
  margin: 10px 0 12px
}

.checklist li {
  list-style: none;
  position: relative;
  padding-left: 24px
}

.checklist li::before {
  content: "\f00c";
  font-family: "Font Awesome 6 Free";
  font-weight: 900;
  color: #16a34a;
  position: absolute;
  left: 0
}

/* Image helpers */
.img-box {
  position: relative;
  background: linear-gradient(135deg, #e6f7fd, #dff5fb);
  border: 1px solid #c9eaf7;
  border-radius: 16px;
  overflow: hidden;
  cursor: zoom-in;
}

.img-box img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s ease;
}

.img-box:hover img {
  transform: scale(1.15);
}

.img-box.no-img {
  background: linear-gradient(135deg, #e6f7fd, #ffffff);
  cursor: default;
}

.ratio-4x3 {
  aspect-ratio: 4/3
}

.ratio-16x9 {
  aspect-ratio: 16/9
}

/* Gallery */
.gallery {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px
}

.gallery figure {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 16px;
  overflow: hidden;
  box-shadow: 0 10px 30px rgba(2, 132, 199, .08)
}

.gallery figcaption {
  padding: 10px 12px;
  color: #0b3045;
  font-weight: 600;
  border-top: 1px solid var(--border);
  position: relative;
  z-index: 2;
  background: #fff;
}

/* SPEC TABLE */
.spec-table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  border: 1px solid var(--border);
  border-radius: 14px;
  overflow: hidden;
  background: #fff
}

.spec-table th,
.spec-table td {
  padding: 12px 14px;
  border-bottom: 1px solid var(--border)
}

.spec-table th {
  color: #0b3045;
  text-align: left;
  font-weight: 700
}

.spec-table tr:last-child th,
.spec-table tr:last-child td {
  border-bottom: 0
}

/* DOWNLOAD BOX */
.download-box {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: #fff;
  border: 1px solid #e5e7eb;
  border-radius: 12px;
  padding: 24px 30px;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.02);
  flex-wrap: wrap;
  gap: 20px;
}

.download-content h3 {
  margin: 0 0 5px 0;
  color: var(--brand-2);
  font-size: 18px;
}

.download-content p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

@media (max-width: 600px) {
  .download-box {
    flex-direction: column;
    text-align: center;
  }
}

/* CTA band */
.cta-band {
  background: linear-gradient(180deg, #e6f7fd 0%, #dff5fb 100%);
  border: 1px solid #c9eaf7;
  border-radius: 16px;
  padding: 16px 18px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  box-shadow: 0 12px 40px rgba(2, 132, 199, .15)
}

.cta-form {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: flex-end
}

.cta-form input {
  padding: 12px;
  border: 1px solid #d1d5db;
  border-radius: 12px;
  width: 230px;
  background: #fff
}

.callout {
  display: flex;
  align-items: center;
  gap: 10px;
  background: #f1fcff;
  border: 1px dashed #9bd9f7;
  border-radius: 12px;
  padding: 10px 12px;
  color: #0b3045;
  margin-top: 10px
}

/* Footer */
footer {
  background: #0c1728;
  color: #e5e7eb;
  margin-top: 36px;
  padding: 56px 0 28px
}

.fgrid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 30px
}

footer h4 {
  color: #fff;
  margin-bottom: 10px
}

footer p,
footer li {
  font-size: 14px;
  line-height: 1.7;
  color: #cbd5e1
}

footer ul {
  list-style: none;
  padding: 0
}

.footer-bottom {
  margin-top: 26px;
  text-align: center;
  border-top: 1px solid rgba(255, 255, 255, .12);
  padding-top: 18px
}

.footer-contact {
  margin-top: 12px;
  display: flex;
  gap: 14px;
  justify-content: center
}

.footer-contact a {
  color: #a5e2fb
}

.footer-contact a:hover {
  text-decoration: underline
}

/* Lightbox */
.lightbox {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.9);
  z-index: 2000;
  display: none;
  justify-content: center;
  align-items: center;
  cursor: zoom-out;
  animation: fadeIn 0.2s ease-out;
}

.lightbox.active {
  display: flex;
}

.lightbox img {
  max-width: 90%;
  max-height: 90%;
  object-fit: contain;
  border-radius: 8px;
  box-shadow: 0 0 30px rgba(0, 0, 0, 0.8);
  cursor: default;
  transform: scale(0.9);
  transition: transform 0.2s;
}

.lightbox.active img {
  transform: scale(1);
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

/* --- ADDED FOR VIDEO DEMO --- */
.video-container {
  position: relative;
  padding-bottom: 56.25%; /* Tỉ lệ khung hình 16:9 */
  height: 0;
  background: #000;
  border-radius: 16px;
  overflow: hidden;
  box-shadow: 0 12px 40px rgba(2, 132, 199, .15);
  border: 1px solid var(--border);
  margin-top: 10px;
}

.video-container video {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}