:root {
  --bg: #0a0e17;
  --bg-card: #121826;
  --bg-elevated: #1a2234;
  --text: #e8ecf4;
  --text-muted: #8b95a8;
  --primary: #3b8ed0;
  --primary-hover: #2d7ab8;
  --zalo: #0068ff;
  --zalo-hover: #0052cc;
  --accent: #22c55e;
  --border: rgba(255, 255, 255, 0.08);
  --radius: 14px;
  --shadow: 0 24px 64px rgba(0, 0, 0, 0.45);
  --font: "Be Vietnam Pro", system-ui, sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 50% at 50% -20%, rgba(59, 142, 208, 0.18), transparent),
    radial-gradient(ellipse 60% 40% at 100% 50%, rgba(0, 104, 255, 0.08), transparent);
  pointer-events: none;
  z-index: -1;
}

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

.container {
  width: min(1120px, 92vw);
  margin-inline: auto;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(10, 14, 23, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  gap: 1rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.05rem;
}

.brand img {
  border-radius: 10px;
}

.nav {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.nav a:not(.btn) {
  color: var(--text-muted);
  font-size: 0.92rem;
  font-weight: 500;
  transition: color 0.2s;
}

.nav a:not(.btn):hover {
  color: var(--text);
}

.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.menu-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 22px;
  border-radius: 10px;
  font-family: inherit;
  font-weight: 600;
  font-size: 0.95rem;
  border: none;
  cursor: pointer;
  transition: transform 0.15s, background 0.2s, box-shadow 0.2s;
  white-space: nowrap;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary), #2563eb);
  color: #fff;
  box-shadow: 0 8px 24px rgba(59, 142, 208, 0.35);
}

.btn-primary:hover {
  background: linear-gradient(135deg, var(--primary-hover), #1d4ed8);
}

.btn-zalo {
  background: var(--zalo);
  color: #fff;
  box-shadow: 0 8px 24px rgba(0, 104, 255, 0.3);
}

.btn-zalo:hover {
  background: var(--zalo-hover);
}

.btn-sm {
  padding: 8px 16px;
  font-size: 0.88rem;
}

.btn-lg {
  padding: 14px 28px;
  font-size: 1rem;
}

/* Hero */
.hero {
  padding: 4rem 0 5rem;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: center;
}

.eyebrow {
  display: inline-block;
  padding: 6px 14px;
  background: rgba(59, 142, 208, 0.15);
  border: 1px solid rgba(59, 142, 208, 0.3);
  border-radius: 999px;
  font-size: 0.82rem;
  font-weight: 600;
  color: #7ec8f0;
  margin-bottom: 1.2rem;
}

.hero h1 {
  font-size: clamp(2rem, 4.5vw, 3rem);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin-bottom: 1rem;
}

.hero h1 em {
  font-style: normal;
  background: linear-gradient(90deg, #7ec8f0, #3b8ed0);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.lead {
  font-size: 1.05rem;
  color: var(--text-muted);
  max-width: 36rem;
  margin-bottom: 1.8rem;
  line-height: 1.7;
}

.lead strong {
  color: var(--text);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 1.5rem;
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  list-style: none;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.hero-meta li::before {
  content: "✓ ";
  color: var(--accent);
}

/* Screenshots */
.hero-visual {
  display: flex;
  justify-content: center;
}

.screenshot-frame,
.demo-wide {
  margin: 0;
  border-radius: 12px;
  overflow: hidden;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  background: var(--bg-card);
}

.screenshot-frame img,
.demo-wide img {
  display: block;
  width: 100%;
  height: auto;
}

.screenshot-frame figcaption {
  padding: 10px 14px;
  font-size: 0.82rem;
  color: var(--text-muted);
  text-align: center;
  border-top: 1px solid var(--border);
  background: var(--bg-elevated);
}

.demo-caption {
  text-align: center;
  color: var(--text-muted);
  font-size: 0.92rem;
  margin-top: 1rem;
  max-width: 640px;
  margin-inline: auto;
  line-height: 1.7;
}

/* Sections */
.section {
  padding: 4.5rem 0;
}

.section-title {
  font-size: clamp(1.6rem, 3vw, 2rem);
  font-weight: 800;
  text-align: center;
  margin-bottom: 0.5rem;
}

.section-title.left {
  text-align: left;
  margin-bottom: 1rem;
}

.section-sub {
  text-align: center;
  color: var(--text-muted);
  margin-bottom: 2.5rem;
}

/* Story */
.story {
  background: rgba(255, 255, 255, 0.02);
  border-block: 1px solid var(--border);
}

.story-grid {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: 2.5rem;
  align-items: start;
}

.story-text {
  color: var(--text-muted);
  margin-bottom: 1rem;
  font-size: 1rem;
  line-height: 1.75;
}

.story-text strong {
  color: var(--text);
}

.story-text.highlight {
  font-size: 1.15rem;
  color: var(--text);
  padding: 1rem 1.2rem;
  background: rgba(59, 142, 208, 0.1);
  border-left: 3px solid var(--primary);
  border-radius: 0 8px 8px 0;
}

.compare-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
}

.compare-card h3 {
  margin-bottom: 1rem;
  font-size: 1rem;
  text-align: center;
}

.compare-col {
  padding: 1rem;
  border-radius: 10px;
  margin-bottom: 0.75rem;
}

.compare-col:last-child {
  margin-bottom: 0;
}

.compare-col.bad {
  background: rgba(239, 68, 68, 0.08);
  border: 1px solid rgba(239, 68, 68, 0.2);
}

.compare-col.good {
  background: rgba(34, 197, 94, 0.08);
  border: 1px solid rgba(34, 197, 94, 0.25);
}

.compare-label {
  display: block;
  font-weight: 700;
  font-size: 0.88rem;
  margin-bottom: 0.6rem;
}

.compare-col ul {
  margin-left: 1.1rem;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.compare-col li {
  margin-bottom: 0.35rem;
}

/* Data fields */
.fields-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
}

.field-pill {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1rem 1.2rem;
}

.field-pill strong {
  display: block;
  font-size: 0.95rem;
  margin-bottom: 0.25rem;
}

.field-pill span {
  font-size: 0.82rem;
  color: var(--text-muted);
}

/* Features */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.25rem;
}

.feature-card.featured {
  grid-column: span 2;
  border-color: rgba(59, 142, 208, 0.3);
  background: linear-gradient(145deg, var(--bg-card), rgba(59, 142, 208, 0.06));
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  transition: border-color 0.2s, transform 0.2s;
}

.feature-card:hover {
  border-color: rgba(59, 142, 208, 0.35);
  transform: translateY(-3px);
}

.feature-icon {
  font-size: 1.6rem;
  margin-bottom: 0.75rem;
  line-height: 1;
}

/* Full box */
.fullbox-inner {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 2rem;
  align-items: center;
  background: linear-gradient(135deg, rgba(34, 197, 94, 0.08), rgba(59, 142, 208, 0.06));
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 2rem 2.5rem;
}

.fullbox-inner h2 {
  font-size: 1.4rem;
  margin-bottom: 0.75rem;
}

.fullbox-inner p {
  color: var(--text-muted);
  line-height: 1.7;
}

.fullbox-list {
  list-style: none;
  display: grid;
  gap: 0.6rem;
}

.fullbox-list li {
  padding: 0.65rem 1rem;
  background: var(--bg-card);
  border-radius: 8px;
  font-size: 0.92rem;
  border: 1px solid var(--border);
}

.fullbox-list li::before {
  content: "✓ ";
  color: var(--accent);
  font-weight: 700;
}

/* Roadmap */
.roadmap-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.25rem;
  max-width: 800px;
  margin-inline: auto;
}

.roadmap-card {
  background: var(--bg-card);
  border: 1px dashed rgba(59, 142, 208, 0.4);
  border-radius: var(--radius);
  padding: 1.5rem;
  position: relative;
}

.roadmap-card .badge {
  display: inline-block;
  padding: 4px 10px;
  background: rgba(251, 191, 36, 0.15);
  color: #fbbf24;
  border-radius: 999px;
  font-size: 0.75rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
}

.roadmap-card h3 {
  font-size: 1.05rem;
  margin-bottom: 0.5rem;
}

.roadmap-card p {
  font-size: 0.9rem;
  color: var(--text-muted);
}

.feature-card h3 {
  font-size: 1.05rem;
  margin-bottom: 0.5rem;
}

.feature-card p {
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* Download */
.download-box {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 2rem;
  background: linear-gradient(145deg, var(--bg-card), var(--bg-elevated));
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 2.5rem;
  box-shadow: var(--shadow);
}

.download-copy h2 {
  font-size: 1.6rem;
  margin-bottom: 0.75rem;
}

.download-copy > p {
  color: var(--text-muted);
  margin-bottom: 1rem;
}

.download-list {
  margin: 0 0 1.5rem 1.2rem;
  color: var(--text-muted);
  font-size: 0.95rem;
}

.download-list li {
  margin-bottom: 0.4rem;
}

.download-list strong {
  color: var(--text);
}

.download-note {
  margin-top: 1rem;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.download-steps {
  background: rgba(0, 0, 0, 0.25);
  border-radius: var(--radius);
  padding: 1.5rem;
  border: 1px solid var(--border);
}

.download-steps h3 {
  margin-bottom: 1rem;
  font-size: 1rem;
}

.download-steps ol {
  margin-left: 1.2rem;
  color: var(--text-muted);
  font-size: 0.92rem;
}

.download-steps li {
  margin-bottom: 0.6rem;
}

.download-steps code {
  background: rgba(255, 255, 255, 0.08);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.85em;
}

/* Guide steps */
.steps-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.step {
  text-align: center;
  padding: 1.5rem;
}

.step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background: linear-gradient(135deg, var(--primary), #2563eb);
  border-radius: 50%;
  font-weight: 800;
  font-size: 1.1rem;
  margin-bottom: 1rem;
}

.step h4 {
  margin-bottom: 0.5rem;
}

.step p {
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* CTA */
.cta-box {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
  flex-wrap: wrap;
  background: linear-gradient(135deg, rgba(0, 104, 255, 0.15), rgba(59, 142, 208, 0.1));
  border: 1px solid rgba(0, 104, 255, 0.25);
  border-radius: 20px;
  padding: 2rem 2.5rem;
}

.cta-box h2 {
  font-size: 1.4rem;
  margin-bottom: 0.4rem;
}

.cta-box p {
  color: var(--text-muted);
  font-size: 0.95rem;
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 2rem 0 1.5rem;
  margin-top: 2rem;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 1rem;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.footer-brand img {
  border-radius: 8px;
}

.footer-brand span {
  display: block;
  font-size: 0.82rem;
  color: var(--text-muted);
}

.footer-links {
  display: flex;
  gap: 1.5rem;
}

.footer-links a {
  color: var(--text-muted);
  font-size: 0.9rem;
}

.footer-links a:hover {
  color: var(--text);
}

.copyright {
  text-align: center;
  font-size: 0.8rem;
  color: var(--text-muted);
  opacity: 0.7;
}

/* Float Zalo */
.float-zalo {
  position: fixed;
  bottom: 24px;
  right: 24px;
  width: 56px;
  height: 56px;
  background: var(--zalo);
  color: #fff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 8px 32px rgba(0, 104, 255, 0.45);
  z-index: 99;
  transition: transform 0.2s, background 0.2s;
}

.float-zalo:hover {
  transform: scale(1.08);
  background: var(--zalo-hover);
}

/* Mobile */
@media (max-width: 900px) {
  .hero-grid,
  .download-box,
  .feature-grid,
  .story-grid,
  .fields-grid,
  .fullbox-inner,
  .roadmap-grid {
    grid-template-columns: 1fr;
  }

  .feature-card.featured {
    grid-column: span 1;
  }

  .section-title.left {
    text-align: center;
  }

  .hero-visual {
    order: -1;
  }

  .hero {
    padding-top: 2rem;
  }

  .steps-row {
    grid-template-columns: 1fr;
  }

  .menu-toggle {
    display: flex;
  }

  .nav {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    flex-direction: column;
    background: var(--bg-card);
    border-bottom: 1px solid var(--border);
    padding: 1rem 1.5rem 1.5rem;
    gap: 0.75rem;
  }

  .nav.open {
    display: flex;
  }

  .nav a:not(.btn) {
    padding: 0.5rem 0;
  }

  .cta-box {
    flex-direction: column;
    text-align: center;
  }
}