/* ==========================================================================
   THE GIOI CONG NGHE - VERCEL STYLE DESIGN SYSTEM
   ========================================================================== */

:root {
  --bg-main: #000000;
  --bg-surface: #0a0a0c;
  --bg-card: rgba(18, 18, 22, 0.7);
  --bg-card-hover: rgba(28, 28, 35, 0.85);
  
  --border-subtle: rgba(255, 255, 255, 0.08);
  --border-hover: rgba(255, 255, 255, 0.2);
  --border-glow: rgba(0, 112, 243, 0.4);

  --text-primary: #ededed;
  --text-secondary: #a1a1aa;
  --text-muted: #71717a;

  --accent-blue: #0070f3;
  --accent-cyan: #00dfd8;
  --accent-purple: #7928ca;
  --accent-pink: #ff0080;
  --accent-green: #10b981;
  --accent-amber: #f59e0b;

  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-display: 'Space Grotesk', var(--font-sans);

  --container-max: 1200px;
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-full: 9999px;
  
  --transition-fast: 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-smooth: 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
  scroll-behavior: smooth;
  color-scheme: dark;
}

body {
  background-color: var(--bg-main);
  color: var(--text-primary);
  font-family: var(--font-sans);
  line-height: 1.6;
  overflow-x: hidden;
  position: relative;
  -webkit-font-smoothing: antialiased;
}

/* Background Glowing Elements */
.glow-bg {
  position: absolute;
  pointer-events: none;
  z-index: 0;
  filter: blur(120px);
  border-radius: 50%;
  opacity: 0.45;
}
.top-glow {
  top: -150px;
  left: 50%;
  transform: translateX(-50%);
  width: 700px;
  height: 400px;
  background: radial-gradient(circle, rgba(0, 112, 243, 0.35) 0%, rgba(121, 40, 202, 0.2) 70%, transparent 100%);
}
.center-glow {
  top: 900px;
  right: -100px;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(255, 0, 128, 0.15) 0%, rgba(0, 223, 216, 0.1) 70%, transparent 100%);
}

.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: 24px;
  padding-right: 24px;
  position: relative;
  z-index: 1;
}

/* Top ribbon banner */
.top-banner {
  background: linear-gradient(90deg, rgba(121, 40, 202, 0.25), rgba(0, 112, 243, 0.25));
  border-bottom: 1px solid var(--border-subtle);
  padding: 10px 0;
  font-size: 0.85rem;
  color: var(--text-secondary);
}
.flex-between {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}
.banner-badge {
  background: var(--accent-purple);
  color: #fff;
  font-size: 0.7rem;
  font-weight: 700;
  padding: 3px 8px;
  border-radius: var(--radius-full);
  letter-spacing: 0.5px;
}
.banner-text strong {
  color: #fff;
}
.banner-link {
  color: var(--accent-cyan);
  text-decoration: none;
  font-weight: 600;
  transition: color var(--transition-fast);
}
.banner-link:hover {
  color: #fff;
}

/* Navbar */
.navbar-wrapper {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  background: rgba(0, 0, 0, 0.75);
  border-bottom: 1px solid var(--border-subtle);
}
.navbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}
.brand-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: #fff;
}
.logo-icon {
  width: 38px;
  height: 38px;
  border-radius: 10px;
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  box-shadow: 0 4px 15px rgba(0, 112, 243, 0.3);
}
.logo-text {
  display: flex;
  flex-direction: column;
}
.logo-title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.05rem;
  letter-spacing: 0.5px;
  line-height: 1.1;
}
.logo-sub {
  font-size: 0.72rem;
  color: var(--text-muted);
  letter-spacing: 0.3px;
}
.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
  list-style: none;
}
.nav-item {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.92rem;
  font-weight: 500;
  transition: color var(--transition-fast);
}
.nav-item:hover {
  color: #fff;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 18px;
}
.status-indicator {
  display: flex;
  align-items: center;
  gap: 8px;
  background: rgba(16, 185, 129, 0.1);
  border: 1px solid rgba(16, 185, 129, 0.25);
  padding: 6px 12px;
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent-green);
}
.pulse-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--accent-green);
  box-shadow: 0 0 8px var(--accent-green);
  animation: pulseAnim 2s infinite;
}
@keyframes pulseAnim {
  0% { transform: scale(0.95); opacity: 0.8; }
  50% { transform: scale(1.3); opacity: 1; }
  100% { transform: scale(0.95); opacity: 0.8; }
}

.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 4px;
}
.mobile-menu-btn span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: transform var(--transition-fast);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-weight: 600;
  text-decoration: none;
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
  cursor: pointer;
  border: 1px solid transparent;
}
.btn-sm {
  padding: 8px 16px;
  font-size: 0.85rem;
}
.btn-lg {
  padding: 14px 28px;
  font-size: 0.95rem;
}
.btn-primary {
  background: #ffffff;
  color: #000000;
}
.btn-primary:hover {
  background: #e6e6e6;
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(255, 255, 255, 0.2);
}
.btn-secondary {
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-primary);
  border-color: var(--border-subtle);
}
.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: var(--border-hover);
  transform: translateY(-2px);
}

/* Hero Section */
.hero-section {
  padding: 100px 24px 80px;
  text-align: center;
}
.hero-content {
  max-width: 860px;
  margin: 0 auto;
}
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border-subtle);
  padding: 6px 18px;
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 28px;
  backdrop-filter: blur(10px);
}
.hero-title {
  font-family: var(--font-display);
  font-size: clamp(2.4rem, 5.5vw, 4.2rem);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -1.5px;
  margin-bottom: 24px;
}
.gradient-text {
  background: linear-gradient(135deg, #ffffff 20%, #a1a1aa 70%, #0070f3 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hero-desc {
  font-size: clamp(1.05rem, 2vw, 1.25rem);
  color: var(--text-secondary);
  line-height: 1.65;
  max-width: 680px;
  margin: 0 auto 36px;
}
.hero-cta-group {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 60px;
}

/* Metrics bar */
.metrics-strip {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 36px;
  padding: 24px 32px;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  backdrop-filter: blur(16px);
  margin-top: 20px;
}
.metric-item {
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.metric-num {
  font-family: var(--font-display);
  font-size: 1.8rem;
  font-weight: 700;
  color: #fff;
  letter-spacing: -0.5px;
}
.metric-label {
  font-size: 0.78rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.8px;
}
.metric-divider {
  width: 1px;
  height: 36px;
  background: var(--border-subtle);
}

/* Sections Global */
.section {
  padding: 90px 24px;
}
.section-header {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 50px;
}
.section-tag {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--accent-blue);
  text-transform: uppercase;
  letter-spacing: 1.5px;
  margin-bottom: 12px;
}
.section-title {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 3.5vw, 2.6rem);
  font-weight: 700;
  letter-spacing: -0.8px;
  margin-bottom: 14px;
}
.section-subtitle {
  font-size: 1.05rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* Interactive Model Lookup */
.search-box-wrapper {
  max-width: 780px;
  margin: 0 auto 40px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.search-input-box {
  position: relative;
  display: flex;
  align-items: center;
}
.search-icon {
  position: absolute;
  left: 20px;
  color: var(--text-muted);
  pointer-events: none;
}
.search-input-box input {
  width: 100%;
  padding: 18px 50px 18px 54px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  font-size: 1rem;
  color: #fff;
  font-family: var(--font-sans);
  outline: none;
  transition: all var(--transition-fast);
  backdrop-filter: blur(12px);
}
.search-input-box input:focus {
  border-color: var(--accent-blue);
  background: rgba(255, 255, 255, 0.07);
  box-shadow: 0 0 25px rgba(0, 112, 243, 0.25);
}
.clear-search-btn {
  position: absolute;
  right: 18px;
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 1.4rem;
  cursor: pointer;
  display: none;
}
.clear-search-btn.active {
  display: block;
}
.search-filter-pills {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  flex-wrap: wrap;
}
.pill {
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border-subtle);
  color: var(--text-secondary);
  padding: 8px 18px;
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-fast);
}
.pill:hover, .pill.active {
  background: rgba(255, 255, 255, 0.12);
  color: #fff;
  border-color: rgba(255, 255, 255, 0.25);
}
.pill.active {
  background: #fff;
  color: #000;
}

/* Models Grid */
.models-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
}
.model-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 22px;
  display: flex;
  flex-direction: column;
  gap: 14px;
  transition: all var(--transition-fast);
  backdrop-filter: blur(12px);
}
.model-card:hover {
  transform: translateY(-4px);
  border-color: var(--border-hover);
  background: var(--bg-card-hover);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
}
.model-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.model-badge {
  font-size: 0.72rem;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: var(--radius-full);
  text-transform: uppercase;
}
.badge-viettel { background: rgba(239, 68, 68, 0.15); color: #f87171; border: 1px solid rgba(239, 68, 68, 0.3); }
.badge-fpt { background: rgba(245, 158, 11, 0.15); color: #fbbf24; border: 1px solid rgba(245, 158, 11, 0.3); }
.badge-generic { background: rgba(59, 130, 246, 0.15); color: #60a5fa; border: 1px solid rgba(59, 130, 246, 0.3); }

.model-name {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 700;
  color: #fff;
}
.model-spec-list {
  display: flex;
  flex-direction: column;
  gap: 6px;
  font-size: 0.85rem;
  color: var(--text-secondary);
}
.spec-row {
  display: flex;
  justify-content: space-between;
}
.spec-label { color: var(--text-muted); }
.spec-value { font-weight: 500; color: #e4e4e7; }
.model-footer {
  margin-top: auto;
  padding-top: 12px;
  border-top: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.status-pill-ok {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent-green);
  display: flex;
  align-items: center;
  gap: 6px;
}

/* Bento Grid */
.bento-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.bento-col-2 {
  grid-column: span 2;
}
.bento-row-2 {
  grid-row: span 2;
}
.bento-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 36px;
  position: relative;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  gap: 16px;
  transition: all var(--transition-smooth);
  backdrop-filter: blur(16px);
}
.bento-card:hover {
  border-color: var(--border-hover);
  background: var(--bg-card-hover);
  transform: translateY(-4px);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.6);
}
.card-icon-badge {
  width: 50px;
  height: 50px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 8px;
}
.icon-purple { background: rgba(121, 40, 202, 0.2); color: #a855f7; border: 1px solid rgba(121, 40, 202, 0.3); }
.icon-blue { background: rgba(0, 112, 243, 0.2); color: #38bdf8; border: 1px solid rgba(0, 112, 243, 0.3); }
.icon-green { background: rgba(16, 185, 129, 0.2); color: #34d399; border: 1px solid rgba(16, 185, 129, 0.3); }
.icon-amber { background: rgba(245, 158, 11, 0.2); color: #fbbf24; border: 1px solid rgba(245, 158, 11, 0.3); }
.icon-rose { background: rgba(244, 63, 94, 0.2); color: #fb7185; border: 1px solid rgba(244, 63, 94, 0.3); }

.card-tag {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1.2px;
  color: var(--text-muted);
}
.card-title {
  font-family: var(--font-display);
  font-size: 1.45rem;
  font-weight: 700;
  letter-spacing: -0.4px;
  color: #fff;
}
.card-desc {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.6;
}
.card-feature-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin: 10px 0;
}
.feature-bullet {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.9rem;
  color: #e4e4e7;
}
.bullet-check {
  color: var(--accent-green);
  font-weight: 800;
}

.card-mockup-preview {
  margin-top: auto;
  padding-top: 24px;
}
.mockup-screen {
  background: #000;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: 0 10px 30px rgba(0,0,0,0.5);
}
.mockup-header {
  background: #111;
  padding: 10px 16px;
  display: flex;
  align-items: center;
  gap: 8px;
  border-bottom: 1px solid var(--border-subtle);
}
.dot { width: 10px; height: 10px; border-radius: 50%; display: inline-block; }
.dot.red { background: #ff5f56; }
.dot.yellow { background: #ffbd2e; }
.dot.green { background: #27c93f; }
.mockup-title {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-left: 10px;
  font-family: monospace;
}
.mockup-body {
  padding: 18px;
  font-family: monospace;
  font-size: 0.85rem;
  display: flex;
  flex-direction: column;
  gap: 6px;
  color: #38bdf8;
}

/* Steps Grid */
.steps-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.step-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 36px 30px;
  display: flex;
  flex-direction: column;
  gap: 14px;
  position: relative;
  transition: all var(--transition-fast);
}
.step-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-4px);
}
.step-num {
  font-family: var(--font-display);
  font-size: 2.8rem;
  font-weight: 800;
  color: rgba(255, 255, 255, 0.12);
  line-height: 1;
}
.step-title {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 700;
  color: #fff;
}
.step-desc {
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* FAQ */
.faq-accordion {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: border-color var(--transition-fast);
}
.faq-item:hover {
  border-color: var(--border-hover);
}
.faq-question {
  width: 100%;
  padding: 22px 24px;
  background: none;
  border: none;
  color: #fff;
  font-family: var(--font-sans);
  font-size: 1.02rem;
  font-weight: 600;
  text-align: left;
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  gap: 16px;
}
.faq-arrow {
  font-size: 1.4rem;
  font-weight: 400;
  color: var(--text-muted);
  transition: transform var(--transition-fast);
}
.faq-item.active .faq-arrow {
  transform: rotate(45deg);
  color: #fff;
}
.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
  padding: 0 24px;
}
.faq-answer p {
  padding-bottom: 22px;
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.65;
}

/* CTA Banner */
.cta-banner {
  background: linear-gradient(135deg, rgba(0, 112, 243, 0.15) 0%, rgba(121, 40, 202, 0.2) 100%);
  border: 1px solid rgba(0, 112, 243, 0.3);
  border-radius: var(--radius-lg);
  padding: 60px 40px;
  text-align: center;
  margin: 60px auto 100px;
  position: relative;
  overflow: hidden;
  box-shadow: 0 20px 50px rgba(0, 112, 243, 0.15);
}
.cta-title {
  font-family: var(--font-display);
  font-size: clamp(2rem, 4vw, 2.8rem);
  font-weight: 800;
  margin-bottom: 16px;
  color: #fff;
}
.cta-desc {
  font-size: 1.1rem;
  color: var(--text-secondary);
  max-width: 620px;
  margin: 0 auto 32px;
}
.cta-btn-group {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}

/* Footer */
.footer-wrapper {
  background: #050507;
  border-top: 1px solid var(--border-subtle);
  padding: 80px 0 40px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 60px;
}
.footer-brand {
  display: flex;
  flex-direction: column;
  gap: 18px;
}
.footer-tagline {
  color: var(--text-muted);
  font-size: 0.92rem;
  line-height: 1.65;
  max-width: 400px;
}
.footer-links-col {
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.col-title {
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 700;
  color: #fff;
  text-transform: uppercase;
  letter-spacing: 0.8px;
}
.footer-links-col ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.footer-links-col a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.9rem;
  transition: color var(--transition-fast);
}
.footer-links-col a:hover {
  color: #fff;
}
.footer-bottom {
  padding-top: 30px;
  border-top: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
  font-size: 0.82rem;
  color: var(--text-muted);
}
.footer-badge {
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border-subtle);
  padding: 4px 12px;
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  color: var(--text-secondary);
}

/* Responsive */
@media (max-width: 992px) {
  .bento-grid {
    grid-template-columns: 1fr;
  }
  .bento-col-2, .bento-row-2 {
    grid-column: span 1;
    grid-row: span 1;
  }
  .steps-grid {
    grid-template-columns: 1fr;
  }
  .footer-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
  }
  .mobile-menu-btn {
    display: flex;
  }
  .nav-links.active {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 72px;
    left: 0;
    width: 100%;
    background: #000;
    border-bottom: 1px solid var(--border-subtle);
    padding: 24px;
    gap: 18px;
  }
  .metrics-strip {
    flex-direction: column;
    gap: 20px;
  }
  .metric-divider {
    width: 60px;
    height: 1px;
  }
}