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

    /* ══════════════════════════════════════════════
       COLOR THEMES — 5 palettes
       Each theme sets: --ac-r/g/b (accent), --se-r/g/b (secondary/CTA)
       Dark/light values computed from these channels
       ══════════════════════════════════════════════ */

    /* Theme channels — mặc định neutral, JS set data-color ngay khi load */
    :root {
      --ac-r: 57;  --ac-g: 255; --ac-b: 20;
      --se-r: 0;   --se-g: 229; --se-b: 255;
    }

    /* Theme: Cyan */
    [data-color="cyan"] {
      --ac-r: 0;   --ac-g: 229; --ac-b: 255; /* #00e5ff */
      --se-r: 0;   --se-g: 255; --se-b: 136; /* #00ff88 */
    }

    /* Theme: Violet */
    [data-color="violet"] {
      --ac-r: 168;
      --ac-g: 85;
      --ac-b: 247;
      /* #a855f7 */
      --se-r: 244;
      --se-g: 63;
      --se-b: 94;
      /* #f43f5e */
    }

    /* Theme: Orange */
    [data-color="orange"] {
      --ac-r: 249;
      --ac-g: 115;
      --ac-b: 22;
      /* #f97316 */
      --se-r: 251;
      --se-g: 191;
      --se-b: 36;
      /* #fbbf24 */
    }

    /* Theme: Gold */
    [data-color="gold"] {
      --ac-r: 212;
      --ac-g: 175;
      --ac-b: 55;
      /* #d4af37 */
      --se-r: 249;
      --se-g: 115;
      --se-b: 22;
      /* #f97316 */
    }

    /* Theme: Rose */
    [data-color="rose"] {
      --ac-r: 236;
      --ac-g: 72;
      --ac-b: 153;
      /* #ec4899 */
      --se-r: 6;
      --se-g: 182;
      --se-b: 212;
      /* #06b6d4 */
    }

    /* Theme: Red */
    [data-color="red"] {
      --ac-r: 255;
      --ac-g: 43;
      --ac-b: 78;
      /* #ff2b4e */
      --se-r: 255;
      --se-g: 107;
      --se-b: 53;
      /* #ff6b35 */
    }

    /* ── Dark mode (default) ────────────────────── */
    :root {
      --bg: #050a0f;
      --bg-2: #080f18;
      --bg-card: #0a1520;
      --bg-card-2: #0d1a28;
      --cyan: rgb(var(--ac-r), var(--ac-g), var(--ac-b));
      --cyan-dim: rgba(var(--ac-r), var(--ac-g), var(--ac-b), 0.08);
      --cyan-border: rgba(var(--ac-r), var(--ac-g), var(--ac-b), 0.18);
      --cyan-glow: 0 0 20px rgba(var(--ac-r), var(--ac-g), var(--ac-b), 0.4), 0 0 60px rgba(var(--ac-r), var(--ac-g), var(--ac-b), 0.15);
      --green: rgb(var(--se-r), var(--se-g), var(--se-b));
      --green-dim: rgba(var(--se-r), var(--se-g), var(--se-b), 0.08);
      --green-border: rgba(var(--se-r), var(--se-g), var(--se-b), 0.2);
      --green-glow: 0 0 15px rgba(var(--se-r), var(--se-g), var(--se-b), 0.5);
      --red: #ff2b4e;
      --red-dim: rgba(255, 43, 78, 0.1);
      --yellow: #ffc107;
      --text-1: #e2f4ff;
      --text-2: #7fa8c4;
      --text-3: #3d6b8a;
      --border: rgba(var(--ac-r), var(--ac-g), var(--ac-b), 0.1);
      --border-2: rgba(255, 255, 255, 0.05);
    }

    /* ── Light mode ─────────────────────────────── */
    [data-theme="light"] {
      --bg: #f0f4f8;
      --bg-2: #e8eef5;
      --bg-card: #ffffff;
      --bg-card-2: #f5f8fb;
      --cyan: rgb(calc(var(--ac-r)*0.6), calc(var(--ac-g)*0.55), calc(var(--ac-b)*0.7));
      --cyan-dim: rgba(var(--ac-r), var(--ac-g), var(--ac-b), 0.08);
      --cyan-border: rgba(var(--ac-r), var(--ac-g), var(--ac-b), 0.22);
      --cyan-glow: 0 4px 20px rgba(var(--ac-r), var(--ac-g), var(--ac-b), 0.2);
      --green: rgb(calc(var(--se-r)*0.55), calc(var(--se-g)*0.5), calc(var(--se-b)*0.55));
      --green-dim: rgba(var(--se-r), var(--se-g), var(--se-b), 0.08);
      --green-border: rgba(var(--se-r), var(--se-g), var(--se-b), 0.2);
      --green-glow: 0 4px 16px rgba(var(--se-r), var(--se-g), var(--se-b), 0.25);
      --red: #cc1133;
      --red-dim: rgba(204, 17, 51, 0.08);
      --yellow: #b45309;
      --text-1: #0d1f2d;
      --text-2: #2c5f7a;
      --text-3: #6b8fa3;
      --border: rgba(var(--ac-r), var(--ac-g), var(--ac-b), 0.18);
      --border-2: rgba(0, 0, 0, 0.07);
    }

    /* light mode per-theme accent text (higher contrast) */
    [data-theme="light"] {
      --cyan: oklch(from rgb(var(--ac-r), var(--ac-g), var(--ac-b)) calc(l*0.55) c h);
    }

    [data-theme="light"][data-color="cyan"] {
      --cyan: #0077aa;
      --green: #008844;
    }

    [data-theme="light"][data-color="violet"] {
      --cyan: #7c22c8;
      --green: #c01040;
    }

    [data-theme="light"][data-color="orange"] {
      --cyan: #c45608;
      --green: #b07000;
    }

    [data-theme="light"][data-color="gold"] {
      --cyan: #9a7010;
      --green: #c45608;
    }

    [data-theme="light"][data-color="rose"] {
      --cyan: #b5186a;
      --green: #0586a0;
    }

    [data-theme="light"][data-color="red"] {
      --cyan: #cc0022;
      --green: #cc4400;
    }

    /* Theme: Green (lá mạ) */
    [data-color="green"] {
      --ac-r: 57;  --ac-g: 255; --ac-b: 20;  /* #39ff14 — neon green */
      --se-r: 0;   --se-g: 229; --se-b: 255; /* #00e5ff — cyan secondary */
    }

    [data-theme="light"][data-color="green"] {
      --cyan: #1a8c00;
      --green: #0077aa;
    }

    /* ── Font mode: readable (default) vs cyber ─── */
    :root {
      --font-heading: 'Be Vietnam Pro', 'Inter', system-ui, sans-serif;
      --font-body: 'Be Vietnam Pro', 'Inter', system-ui, sans-serif;
      --font-mono: 'Fira Code', 'Cascadia Code', 'Courier New', monospace;
    }

    [data-font="cyber"] {
      --font-heading: 'Orbitron', monospace;
      --font-body: 'Exo 2', system-ui, sans-serif;
      --font-mono: 'Share Tech Mono', monospace;
    }

    [data-font="readable"] {
      --font-heading: 'Be Vietnam Pro', 'Inter', system-ui, sans-serif;
      --font-body: 'Be Vietnam Pro', 'Inter', system-ui, sans-serif;
      --font-mono: 'Fira Code', 'Cascadia Code', 'Courier New', monospace;
    }

    html {
      scroll-behavior: smooth;
    }

    body {
      background: var(--bg);
      color: var(--text-1);
      font-family: var(--font-body);
      line-height: 1.6;
      overflow-x: hidden;
      transition: background 0.3s, color 0.3s;
    }

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

    .container {
      max-width: 1140px;
      margin: 0 auto;
      padding: 0 1.5rem;
    }

    /* ── Scanlines overlay (dark only) ──────────── */
    body::before {
      content: '';
      position: fixed;
      inset: 0;
      background: repeating-linear-gradient(0deg,
          transparent,
          transparent 2px,
          rgba(0, 0, 0, 0.03) 2px,
          rgba(0, 0, 0, 0.03) 4px);
      pointer-events: none;
      z-index: 9999;
      opacity: 1;
      transition: opacity 0.3s;
    }

    [data-theme="light"] body::before {
      opacity: 0;
    }

    /* ── Navbar ─────────────────────────────────── */
    nav {
      position: fixed;
      top: 1rem;
      left: 50%;
      transform: translateX(-50%);
      width: calc(100% - 3rem);
      max-width: 1140px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 0.75rem 1.5rem;
      background: rgba(5, 10, 15, 0.85);
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      border: 1px solid var(--cyan-border);
      border-radius: 4px;
      z-index: 100;
      box-shadow: 0 0 30px rgba(var(--ac-r), var(--ac-g), var(--ac-b), 0.05), inset 0 1px 0 rgba(var(--ac-r), var(--ac-g), var(--ac-b), 0.05);
    }

    [data-theme="light"] nav {
      background: rgba(240, 244, 248, 0.92);
      box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    }

    /* Corner brackets */
    nav::before,
    nav::after {
      content: '';
      position: absolute;
      width: 10px;
      height: 10px;
      border-color: var(--cyan);
      border-style: solid;
      opacity: 0.6;
    }

    nav::before {
      top: -1px;
      left: -1px;
      border-width: 2px 0 0 2px;
    }

    nav::after {
      top: -1px;
      right: -1px;
      border-width: 2px 2px 0 0;
    }

    .nav-logo {
      display: flex;
      align-items: center;
      gap: 0.6rem;
      font-family: 'Orbitron', monospace;
      font-weight: 700;
      font-size: 1rem;
      color: var(--cyan);
      letter-spacing: 0.08em;
      text-shadow: var(--cyan-glow);
    }

    .nav-logo-dot {
      width: 8px;
      height: 8px;
      border-radius: 50%;
      background: var(--green);
      box-shadow: var(--green-glow);
      animation: blink 2s ease-in-out infinite;
    }

    @keyframes blink {

      0%,
      100% {
        opacity: 1;
      }

      50% {
        opacity: 0.3;
      }
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 1.75rem;
      list-style: none;
    }

    .nav-links a {
      font-family: var(--font-body);
      font-size: 0.82rem;
      font-weight: 600;
      color: var(--text-2);
      letter-spacing: 0.03em;
      text-transform: uppercase;
      transition: color 150ms, text-shadow 150ms;
    }

    .nav-links a:hover {
      color: var(--cyan);
      text-shadow: 0 0 10px rgba(var(--ac-r), var(--ac-g), var(--ac-b), 0.5);
    }

    .nav-cta {
      padding: 0.45rem 1.2rem;
      background: transparent;
      color: var(--cyan) !important;
      border: 1px solid var(--cyan);
      border-radius: 2px;
      font-family: var(--font-heading) !important;
      font-size: 0.72rem !important;
      font-weight: 700 !important;
      letter-spacing: 0.05em;
      cursor: pointer;
      transition: background 150ms, box-shadow 150ms !important;
      text-transform: uppercase;
    }

    .nav-cta:hover {
      background: rgba(var(--ac-r), var(--ac-g), var(--ac-b), 0.08) !important;
      box-shadow: var(--cyan-glow) !important;
      color: var(--cyan) !important;
    }

    .theme-btn,
    .font-btn,
    .lang-btn {
      display: flex;
      align-items: center;
      justify-content: center;
      width: 34px;
      height: 34px;
      background: transparent;
      border: 1px solid var(--border);
      border-radius: 2px;
      color: var(--text-2);
      cursor: pointer;
      transition: border-color 150ms, color 150ms;
      flex-shrink: 0;
    }

    .theme-btn:hover,
    .font-btn:hover {
      border-color: var(--cyan);
      color: var(--cyan);
    }

    .nav-controls {
      display: flex;
      align-items: center;
      gap: 0.5rem;
      flex-shrink: 0;
    }

    .font-btn {
      font-size: 0.72rem;
      font-weight: 700;
      letter-spacing: 0.01em;
    }

    #icon-font-readable {
      font-family: 'Be Vietnam Pro', 'Inter', sans-serif;
      font-size: 0.75rem;
    }

    #icon-font-cyber {
      font-family: 'Orbitron', monospace;
      font-size: 0.52rem;
      letter-spacing: 0.05em;
    }

    /* ── Color cycle button ─────────────────────── */
    .color-cycle-btn {
      display: flex; align-items: center; justify-content: center;
      width: 34px; height: 34px;
      background: transparent;
      border: 1px solid var(--border);
      border-radius: 2px;
      cursor: pointer;
      transition: border-color 150ms, box-shadow 150ms;
      flex-shrink: 0;
      padding: 0;
    }

    .color-cycle-btn:hover { border-color: var(--cyan); box-shadow: 0 0 8px rgba(var(--ac-r),var(--ac-g),var(--ac-b),0.3); }

    .color-cycle-dot {
      width: 12px; height: 12px;
      border-radius: 50%;
      background: var(--cyan);
      box-shadow: 0 0 8px rgba(var(--ac-r),var(--ac-g),var(--ac-b),0.7);
      transition: background 200ms, box-shadow 200ms;
      flex-shrink: 0;
    }

    /* ── Hero ───────────────────────────────────── */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      position: relative;
      padding: 7rem 0 5rem;
      overflow: hidden;
    }

    /* Grid background */
    .hero-grid {
      position: absolute;
      inset: 0;
      background-image:
        linear-gradient(rgba(var(--ac-r), var(--ac-g), var(--ac-b), 0.04) 1px, transparent 1px),
        linear-gradient(90deg, rgba(var(--ac-r), var(--ac-g), var(--ac-b), 0.04) 1px, transparent 1px);
      background-size: 48px 48px;
      mask-image: radial-gradient(ellipse 80% 80% at 50% 50%, black 40%, transparent 100%);
    }

    [data-theme="light"] .hero-grid {
      background-image:
        linear-gradient(rgba(var(--ac-r), var(--ac-g), var(--ac-b), 0.1) 1px, transparent 1px),
        linear-gradient(90deg, rgba(var(--ac-r), var(--ac-g), var(--ac-b), 0.1) 1px, transparent 1px);
    }

    /* Glow orbs */
    .hero-orb {
      position: absolute;
      border-radius: 50%;
      filter: blur(80px);
      pointer-events: none;
    }

    .orb-cyan {
      width: 500px;
      height: 500px;
      background: radial-gradient(circle, rgba(0, 229, 255, 0.12) 0%, transparent 70%);
      top: -100px;
      right: -100px;
      animation: drift 12s ease-in-out infinite;
    }

    .orb-green {
      width: 350px;
      height: 350px;
      background: radial-gradient(circle, rgba(0, 255, 136, 0.08) 0%, transparent 70%);
      bottom: 10%;
      left: 5%;
      animation: drift 10s ease-in-out infinite reverse;
    }

    @keyframes drift {

      0%,
      100% {
        transform: translate(0, 0);
      }

      33% {
        transform: translate(20px, -30px);
      }

      66% {
        transform: translate(-15px, 20px);
      }
    }

    @media (prefers-reduced-motion: reduce) {

      .orb-cyan,
      .orb-green,
      .nav-logo-dot {
        animation: none;
      }
    }

    /* Scan line */
    .hero-scan {
      position: absolute;
      left: 0;
      right: 0;
      height: 1px;
      background: linear-gradient(90deg, transparent, var(--cyan), transparent);
      opacity: 0.5;
      animation: scan-v 6s linear infinite;
    }

    @keyframes scan-v {
      0% {
        top: 0%;
        opacity: 0.6;
      }

      90% {
        opacity: 0.1;
      }

      100% {
        top: 100%;
        opacity: 0;
      }
    }

    @media (prefers-reduced-motion: reduce) {
      .hero-scan {
        animation: none;
      }
    }

    .hero>.container {
      position: relative;
      z-index: 1;
    }

    .hero-eyebrow {
      display: inline-flex;
      align-items: center;
      gap: 0.5rem;
      font-family: var(--font-mono);
      font-size: 0.78rem;
      color: var(--green);
      letter-spacing: 0.12em;
      margin-bottom: 1.5rem;
      text-shadow: var(--green-glow);
    }

    .hero-eyebrow::before {
      content: '> ';
      color: var(--cyan);
      opacity: 0.6;
    }

    .hero-title {
      font-family: var(--font-heading);
      font-size: clamp(2.2rem, 5.5vw, 4.5rem);
      font-weight: 900;
      line-height: 1.05;
      letter-spacing: -0.01em;
      margin-bottom: 0.5rem;
      color: var(--text-1);
    }

    .hero-title .line-accent {
      display: block;
      color: var(--cyan);
      text-shadow: var(--cyan-glow);
    }

    .hero-title .line-sub {
      display: block;
      font-size: clamp(1rem, 2vw, 1.6rem);
      color: var(--text-2);
      font-weight: 400;
      letter-spacing: 0.12em;
      margin-top: 0.5rem;
      text-shadow: none;
      white-space: nowrap;
    }

    .sub-br { display: none; }

    @media (max-width: 900px) {
      .hero-title .line-sub {
        white-space: normal;
        font-size: clamp(0.8rem, 3.2vw, 1rem);
        letter-spacing: 0.08em;
      }
      .sub-br { display: inline; }
    }

    /* Glitch effect on title */
    .glitch {
      position: relative;
    }

    .glitch::before,
    .glitch::after {
      content: attr(data-text);
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      font-family: inherit;
      font-size: inherit;
      font-weight: inherit;
    }

    .glitch::before {
      color: #ff2b4e;
      clip-path: polygon(0 30%, 100% 30%, 100% 50%, 0 50%);
      animation: glitch-1 4s infinite linear;
    }

    .glitch::after {
      color: var(--cyan);
      clip-path: polygon(0 60%, 100% 60%, 100% 75%, 0 75%);
      animation: glitch-2 4s infinite linear;
    }

    @keyframes glitch-1 {

      0%,
      94%,
      100% {
        transform: none;
        opacity: 0;
      }

      95% {
        transform: translateX(-3px) skewX(-5deg);
        opacity: 0.8;
      }

      97% {
        transform: translateX(3px) skewX(3deg);
        opacity: 0.6;
      }
    }

    @keyframes glitch-2 {

      0%,
      94%,
      100% {
        transform: none;
        opacity: 0;
      }

      96% {
        transform: translateX(3px) skewX(3deg);
        opacity: 0.7;
      }

      98% {
        transform: translateX(-2px);
        opacity: 0.5;
      }
    }

    @media (prefers-reduced-motion: reduce) {

      .glitch::before,
      .glitch::after {
        display: none;
      }
    }

    .hero-desc {
      font-size: 1.05rem;
      color: var(--text-2);
      max-width: 560px;
      margin: 1.75rem 0 2.5rem;
      line-height: 1.8;
    }

    .hero-ctas {
      display: flex;
      gap: 1rem;
      flex-wrap: wrap;
      margin-bottom: 3rem;
    }

    /* ── Buttons ────────────────────────────────── */
    .btn-cyber {
      display: inline-flex;
      align-items: center;
      gap: 0.5rem;
      padding: 0.875rem 2rem;
      background: transparent;
      color: var(--cyan);
      border: 1px solid var(--cyan);
      border-radius: 2px;
      font-family: var(--font-heading);
      font-size: 0.75rem;
      font-weight: 700;
      letter-spacing: 0.1em;
      text-transform: uppercase;
      cursor: pointer;
      position: relative;
      transition: box-shadow 200ms, background 200ms;
      overflow: hidden;
    }

    .btn-cyber::before {
      content: '';
      position: absolute;
      inset: 0;
      background: linear-gradient(135deg, rgba(0, 229, 255, 0.12), transparent);
      opacity: 0;
      transition: opacity 200ms;
    }

    .btn-cyber:hover {
      box-shadow: var(--cyan-glow);
      color: var(--cyan);
    }

    .btn-cyber:hover::before {
      opacity: 1;
    }

    .btn-cyber-green {
      color: var(--green);
      border-color: var(--green);
    }

    .btn-cyber-green:hover {
      box-shadow: var(--green-glow);
      color: var(--green);
    }

    .btn-cyber-green::before {
      background: linear-gradient(135deg, rgba(0, 255, 136, 0.12), transparent);
    }

    .btn-ghost-cyber {
      display: inline-flex;
      align-items: center;
      gap: 0.5rem;
      padding: 0.875rem 1.75rem;
      background: transparent;
      color: var(--text-2);
      border: 1px solid var(--border-2);
      border-radius: 2px;
      font-family: var(--font-body);
      font-size: 0.875rem;
      font-weight: 600;
      cursor: pointer;
      transition: border-color 200ms, color 200ms;
    }

    .btn-ghost-cyber:hover {
      border-color: var(--cyan-border);
      color: var(--cyan);
    }

    /* ── Trust bar ──────────────────────────────── */
    .trust-bar {
      display: flex;
      align-items: center;
      gap: 2rem;
      flex-wrap: wrap;
      padding-top: 2rem;
      border-top: 1px solid var(--border-2);
    }

    .trust-label {
      font-family: var(--font-mono);
      font-size: 0.7rem;
      color: var(--text-3);
      letter-spacing: 0.1em;
      text-transform: uppercase;
    }

    .trust-items {
      display: flex;
      gap: 1.5rem;
      flex-wrap: wrap;
    }

    .trust-item {
      display: flex;
      align-items: center;
      gap: 0.4rem;
      font-size: 0.82rem;
      font-weight: 600;
      color: var(--text-2);
    }

    .trust-item svg {
      color: var(--green);
      flex-shrink: 0;
    }

    /* ── Stats ──────────────────────────────────── */
    .stats-section {
      background: var(--bg-2);
      border-top: 1px solid var(--cyan-border);
      border-bottom: 1px solid var(--cyan-border);
      padding: 0;
      position: relative;
      overflow: hidden;
    }

    .stats-section::before {
      content: '';
      position: absolute;
      inset: 0;
      background: linear-gradient(90deg, transparent, rgba(0, 229, 255, 0.03), transparent);
      pointer-events: none;
    }

    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
    }

    .stat-item {
      padding: 3rem 1.5rem;
      text-align: center;
      border-right: 1px solid var(--border-2);
      position: relative;
    }

    .stat-item:last-child {
      border-right: none;
    }

    .stat-item::before {
      content: '';
      position: absolute;
      top: 0;
      left: 50%;
      transform: translateX(-50%);
      width: 40px;
      height: 2px;
      background: var(--cyan);
      box-shadow: var(--cyan-glow);
    }

    .stat-value {
      font-family: var(--font-heading);
      font-size: 2.75rem;
      font-weight: 800;
      color: var(--cyan);
      text-shadow: var(--cyan-glow);
      line-height: 1;
      margin-bottom: 0.5rem;
    }

    .stat-label {
      font-size: 0.72rem;
      font-weight: 600;
      color: var(--text-3);
      text-transform: uppercase;
      letter-spacing: 0.1em;
    }

    /* ── Section base ───────────────────────────── */
    section {
      padding: 6rem 0;
    }

    .section-eyebrow {
      display: inline-flex;
      align-items: center;
      gap: 0.5rem;
      font-family: var(--font-mono);
      font-size: 0.72rem;
      color: var(--cyan);
      letter-spacing: 0.15em;
      text-transform: uppercase;
      margin-bottom: 1rem;
    }

    .section-eyebrow::before {
      content: '//';
      opacity: 0.5;
    }

    .section-title {
      font-family: var(--font-heading);
      font-size: clamp(1.5rem, 3vw, 2.25rem);
      font-weight: 700;
      color: var(--text-1);
      line-height: 1.2;
      letter-spacing: -0.01em;
      margin-bottom: 1rem;
    }

    .section-desc {
      font-size: 1rem;
      color: var(--text-2);
      max-width: 540px;
      line-height: 1.75;
    }

    .section-header {
      margin-bottom: 3.5rem;
    }

    .section-header-center {
      text-align: center;
    }

    .section-header-center .section-desc {
      margin: 0 auto;
    }

    /* HUD border card mixin */
    .hud-card {
      position: relative;
      background: var(--bg-card);
      border: 1px solid var(--border);
      border-radius: 4px;
      transition: border-color 200ms, box-shadow 200ms, transform 150ms;
    }

    .hud-card::before,
    .hud-card::after {
      content: '';
      position: absolute;
      width: 8px;
      height: 8px;
      border-color: var(--cyan);
      border-style: solid;
      opacity: 0.4;
      transition: opacity 200ms;
    }

    .hud-card::before {
      bottom: -1px;
      right: -1px;
      border-width: 0 2px 2px 0;
    }

    .hud-card::after {
      bottom: -1px;
      left: -1px;
      border-width: 0 0 2px 2px;
    }

    .hud-card:hover {
      border-color: var(--cyan-border);
      box-shadow: 0 0 30px rgba(0, 229, 255, 0.07);
      transform: translateY(-3px);
    }

    .hud-card:hover::before,
    .hud-card:hover::after {
      opacity: 1;
    }

    /* ── Problems ───────────────────────────────── */
    .problems-section {
      background: var(--bg-2);
    }

    .problems-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 1.5rem;
    }

    .problem-card {
      padding: 1.75rem;
      cursor: default;
    }

    .problem-icon {
      width: 46px;
      height: 46px;
      display: flex;
      align-items: center;
      justify-content: center;
      background: rgba(255, 43, 78, 0.1);
      border: 1px solid rgba(255, 43, 78, 0.2);
      border-radius: 2px;
      color: var(--red);
      margin-bottom: 1.25rem;
    }

    .problem-card h3 {
      font-family: var(--font-heading);
      font-size: 0.88rem;
      font-weight: 700;
      color: var(--text-1);
      margin-bottom: 0.6rem;
      letter-spacing: 0.03em;
    }

    .problem-card p {
      font-size: 0.875rem;
      color: var(--text-2);
      line-height: 1.65;
    }

    /* ── Services ───────────────────────────────── */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 1.5rem;
    }

    .service-card {
      padding: 2rem;
      cursor: default;
    }

    .service-icon {
      width: 50px;
      height: 50px;
      display: flex;
      align-items: center;
      justify-content: center;
      background: var(--cyan-dim);
      border: 1px solid var(--cyan-border);
      border-radius: 2px;
      color: var(--cyan);
      margin-bottom: 1.25rem;
      transition: box-shadow 200ms;
    }

    .service-card:hover .service-icon {
      box-shadow: var(--cyan-glow);
    }

    .service-card h3 {
      font-family: var(--font-heading);
      font-size: 0.85rem;
      font-weight: 700;
      color: var(--text-1);
      margin-bottom: 0.6rem;
      letter-spacing: 0.03em;
    }

    .service-card p {
      font-size: 0.875rem;
      color: var(--text-2);
      line-height: 1.65;
      margin-bottom: 1.25rem;
    }

    .service-tags {
      display: flex;
      flex-wrap: wrap;
      gap: 0.4rem;
    }

    .stag {
      padding: 0.2rem 0.6rem;
      background: var(--cyan-dim);
      color: var(--cyan);
      border: 1px solid var(--cyan-border);
      border-radius: 2px;
      font-family: var(--font-mono);
      font-size: 0.65rem;
      letter-spacing: 0.05em;
    }

    /* ── How it works ───────────────────────────── */
    .how-section {
      background: var(--bg-2);
    }

    .steps-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 1.5rem;
      position: relative;
    }

    .steps-grid::before {
      content: '';
      position: absolute;
      top: 27px;
      left: calc(12.5% + 27px);
      right: calc(12.5% + 27px);
      height: 1px;
      background: linear-gradient(90deg, var(--cyan-border), var(--cyan), var(--cyan-border));
      box-shadow: 0 0 8px rgba(0, 229, 255, 0.3);
      z-index: 0;
    }

    .step-card {
      text-align: center;
      position: relative;
      z-index: 1;
    }

    .step-num {
      width: 54px;
      height: 54px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 1.25rem;
      background: var(--bg-card);
      border: 1px solid var(--cyan-border);
      border-radius: 2px;
      font-family: var(--font-mono);
      font-size: 1rem;
      font-weight: 700;
      color: var(--cyan);
      transition: background 200ms, box-shadow 200ms;
    }

    .step-card:hover .step-num {
      background: var(--cyan-dim);
      box-shadow: var(--cyan-glow);
    }

    .step-card h3 {
      font-family: var(--font-heading);
      font-size: 0.8rem;
      font-weight: 700;
      color: var(--text-1);
      margin-bottom: 0.5rem;
      letter-spacing: 0.03em;
    }

    .step-card p {
      font-size: 0.82rem;
      color: var(--text-2);
      line-height: 1.6;
    }

    /* ── Why us ─────────────────────────────────── */
    .why-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 4rem;
      align-items: center;
    }

    /* Terminal mockup */
    .terminal {
      background: #020a10;
      border: 1px solid var(--cyan-border);
      border-radius: 4px;
      overflow: hidden;
      box-shadow: var(--cyan-glow), 0 20px 60px rgba(0, 0, 0, 0.4);
      font-family: var(--font-mono);
    }

    [data-theme="light"] .terminal {
      background: #f8fafc;
    }

    .term-bar {
      padding: 0.65rem 1rem;
      background: rgba(0, 229, 255, 0.05);
      border-bottom: 1px solid var(--cyan-border);
      display: flex;
      align-items: center;
      gap: 0.4rem;
    }

    .term-dot {
      width: 10px;
      height: 10px;
      border-radius: 50%;
    }

    .term-dot-r {
      background: #ff2b4e;
    }

    .term-dot-y {
      background: #ffc107;
    }

    .term-dot-g {
      background: var(--green);
      box-shadow: 0 0 6px var(--green);
    }

    .term-title {
      font-size: 0.65rem;
      color: var(--text-3);
      margin-left: 0.4rem;
      letter-spacing: 0.08em;
    }

    .term-body {
      padding: 1.25rem;
    }

    .term-line {
      font-size: 0.72rem;
      line-height: 1.8;
      color: var(--text-2);
      opacity: 0;
      animation: type-in 0.3s ease both;
    }

    .term-line:nth-child(1) {
      animation-delay: 0.3s;
    }

    .term-line:nth-child(2) {
      animation-delay: 0.6s;
    }

    .term-line:nth-child(3) {
      animation-delay: 0.9s;
    }

    .term-line:nth-child(4) {
      animation-delay: 1.2s;
    }

    .term-line:nth-child(5) {
      animation-delay: 1.5s;
    }

    .term-line:nth-child(6) {
      animation-delay: 1.8s;
    }

    .term-line:nth-child(7) {
      animation-delay: 2.1s;
    }

    .term-line:nth-child(8) {
      animation-delay: 2.4s;
    }

    .term-line:nth-child(9) {
      animation-delay: 2.7s;
    }

    .term-line:nth-child(10) {
      animation-delay: 3.0s;
    }

    .term-line:nth-child(11) {
      animation-delay: 3.3s;
    }

    @keyframes type-in {
      from {
        opacity: 0;
        transform: translateX(-4px);
      }

      to {
        opacity: 1;
        transform: none;
      }
    }

    @media (prefers-reduced-motion: reduce) {
      .term-line {
        animation: none;
        opacity: 1;
      }
    }

    .tc {
      color: var(--cyan);
    }

    .tg {
      color: var(--green);
      text-shadow: 0 0 8px rgba(0, 255, 136, 0.4);
    }

    .tr {
      color: var(--red);
    }

    .ty {
      color: var(--yellow);
    }

    .td {
      color: var(--text-3);
    }

    .sub-cursor {
      display: inline;
      color: var(--cyan);
      font-weight: 400;
      animation: cursor-blink 1s step-end infinite;
      margin-left: 0.05em;
    }

    .cursor {
      display: inline-block;
      width: 8px;
      height: 14px;
      background: var(--cyan);
      vertical-align: middle;
      margin-left: 2px;
      animation: cursor-blink 1s step-end infinite;
    }

    @keyframes cursor-blink {

      0%,
      100% {
        opacity: 1;
      }

      50% {
        opacity: 0;
      }
    }

    /* Why list */
    .why-list {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 1.5rem;
    }

    .why-item {
      display: flex;
      gap: 1rem;
      align-items: flex-start;
    }

    .why-icon {
      width: 42px;
      height: 42px;
      flex-shrink: 0;
      display: flex;
      align-items: center;
      justify-content: center;
      background: var(--cyan-dim);
      border: 1px solid var(--cyan-border);
      border-radius: 2px;
      color: var(--cyan);
      transition: box-shadow 200ms;
    }

    .why-item:hover .why-icon {
      box-shadow: var(--cyan-glow);
    }

    .why-item h4 {
      font-family: var(--font-heading);
      font-size: 0.82rem;
      font-weight: 700;
      color: var(--text-1);
      margin-bottom: 0.3rem;
      letter-spacing: 0.03em;
    }

    .why-item p {
      font-size: 0.85rem;
      color: var(--text-2);
      line-height: 1.6;
    }

    /* ── Testimonials ───────────────────────────── */
    .testimonials-section {
      background: var(--bg-2);
    }

    .testimonials-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 1.5rem;
    }

    .testimonial-card {
      padding: 1.75rem;
      cursor: default;
    }

    .quote-mark {
      font-family: var(--font-heading);
      font-size: 2rem;
      color: var(--cyan);
      opacity: 0.3;
      line-height: 1;
      margin-bottom: 0.75rem;
    }

    .testimonial-quote {
      font-size: 0.875rem;
      color: var(--text-2);
      line-height: 1.75;
      margin-bottom: 1.25rem;
      font-style: italic;
    }

    .testimonial-author {
      display: flex;
      align-items: center;
      gap: 0.75rem;
    }

    .author-avatar {
      width: 38px;
      height: 38px;
      border-radius: 2px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-family: var(--font-mono);
      font-weight: 700;
      font-size: 0.875rem;
      color: var(--bg);
      flex-shrink: 0;
    }

    .author-name {
      font-family: var(--font-body);
      font-size: 0.875rem;
      font-weight: 700;
      color: var(--text-1);
    }

    .author-role {
      font-size: 0.75rem;
      color: var(--text-3);
      font-family: var(--font-mono);
    }

    /* ── Pricing ────────────────────────────────── */
    .pricing-section {
      background: var(--bg);
    }

    .pricing-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 1.5rem;
      align-items: start;
    }

    .pricing-card {
      padding: 2rem;
      cursor: default;
    }

    .pricing-card.featured {
      border-color: var(--cyan);
      box-shadow: var(--cyan-glow);
      position: relative;
    }

    .popular-badge {
      position: absolute;
      top: -12px;
      left: 50%;
      transform: translateX(-50%);
      padding: 0.2rem 1rem;
      background: var(--cyan);
      color: var(--bg);
      border-radius: 2px;
      font-family: var(--font-heading);
      font-size: 0.6rem;
      font-weight: 700;
      white-space: nowrap;
      letter-spacing: 0.1em;
      text-transform: uppercase;
    }

    .plan-name {
      font-family: var(--font-mono);
      font-size: 0.72rem;
      color: var(--text-3);
      letter-spacing: 0.15em;
      text-transform: uppercase;
      margin-bottom: 0.75rem;
    }

    .featured .plan-name {
      color: var(--cyan);
    }

    .plan-price {
      font-family: var(--font-heading);
      font-size: 2rem;
      font-weight: 700;
      color: var(--text-1);
      line-height: 1;
      margin-bottom: 0.25rem;
    }

    .featured .plan-price {
      color: var(--cyan);
      text-shadow: var(--cyan-glow);
    }

    .plan-period {
      font-size: 0.78rem;
      color: var(--text-3);
      margin-bottom: 1.5rem;
      font-family: var(--font-mono);
    }

    .plan-divider {
      height: 1px;
      background: var(--border-2);
      margin-bottom: 1.5rem;
    }

    .featured .plan-divider {
      background: var(--cyan-border);
    }

    .plan-features {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 0.75rem;
      margin-bottom: 2rem;
    }

    .plan-features li {
      display: flex;
      align-items: flex-start;
      gap: 0.6rem;
      font-size: 0.875rem;
      color: var(--text-2);
    }

    .plan-features li svg {
      flex-shrink: 0;
      margin-top: 2px;
    }

    .check-cyan {
      color: var(--cyan);
    }

    .check-green {
      color: var(--green);
    }

    .plan-btn {
      display: block;
      width: 100%;
      padding: 0.875rem;
      border-radius: 2px;
      text-align: center;
      font-family: var(--font-heading);
      font-size: 0.72rem;
      font-weight: 700;
      letter-spacing: 0.1em;
      text-transform: uppercase;
      cursor: pointer;
      transition: box-shadow 180ms, background 180ms;
    }

    .plan-btn-outline {
      background: transparent;
      color: var(--text-2);
      border: 1px solid var(--border);
    }

    .plan-btn-outline:hover {
      border-color: var(--cyan-border);
      color: var(--cyan);
    }

    .plan-btn-cyber {
      background: transparent;
      color: var(--cyan);
      border: 1px solid var(--cyan);
    }

    .plan-btn-cyber:hover {
      box-shadow: var(--cyan-glow);
      background: var(--cyan-dim);
    }

    /* ── CTA section ────────────────────────────── */
    .cta-section {
      background: var(--bg-2);
      border-top: 1px solid var(--cyan-border);
      position: relative;
      overflow: hidden;
    }

    .cta-section::before {
      content: '';
      position: absolute;
      top: -200px;
      left: 50%;
      transform: translateX(-50%);
      width: 600px;
      height: 400px;
      background: radial-gradient(ellipse, rgba(0, 229, 255, 0.08) 0%, transparent 70%);
      pointer-events: none;
    }

    .cta-content {
      text-align: center;
      position: relative;
      z-index: 1;
    }

    .cta-content h2 {
      font-family: var(--font-heading);
      font-size: clamp(1.5rem, 3.5vw, 2.5rem);
      font-weight: 800;
      color: var(--text-1);
      letter-spacing: -0.01em;
      margin-bottom: 1rem;
    }

    .cta-content p {
      font-size: 1rem;
      color: var(--text-2);
      margin-bottom: 2.5rem;
      max-width: 480px;
      margin-left: auto;
      margin-right: auto;
    }

    .cta-btns {
      display: flex;
      gap: 1rem;
      justify-content: center;
      flex-wrap: wrap;
    }

    /* ── Footer ─────────────────────────────────── */
    footer {
      background: var(--bg);
      border-top: 1px solid var(--border-2);
      padding: 2rem 0;
    }

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

    .footer-logo {
      display: flex;
      align-items: center;
      gap: 0.6rem;
      font-family: var(--font-heading);
      font-size: 0.85rem;
      font-weight: 700;
      color: var(--cyan);
      text-shadow: 0 0 10px rgba(0, 229, 255, 0.3);
    }

    .footer-links {
      display: flex;
      gap: 2rem;
      list-style: none;
    }

    .footer-links a {
      font-size: 0.78rem;
      color: var(--text-3);
      font-family: var(--font-mono);
      letter-spacing: 0.05em;
      transition: color 150ms;
    }

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

    /* ── Scroll reveal ──────────────────────────── */
    .reveal {
      opacity: 0;
      transform: translateY(20px);
      transition: opacity 0.55s ease, transform 0.55s ease;
    }

    .reveal.visible {
      opacity: 1;
      transform: none;
    }

    .reveal-delay-1 {
      transition-delay: 0.1s;
    }

    .reveal-delay-2 {
      transition-delay: 0.2s;
    }

    .reveal-delay-3 {
      transition-delay: 0.3s;
    }

    @media (prefers-reduced-motion: reduce) {
      .reveal {
        opacity: 1;
        transform: none;
        transition: none;
      }
    }

    /* ── Responsive ─────────────────────────────── */
    @media (max-width: 1024px) {
      .why-grid {
        grid-template-columns: 1fr;
      }

      .steps-grid {
        grid-template-columns: repeat(2, 1fr);
      }

      .steps-grid::before {
        display: none;
      }
    }

    @media (max-width: 768px) {
      /* Mobile default: Orbitron chỉ khi chưa có data-font (chưa toggle thủ công) */
      html:not([data-font]) {
        --font-heading: 'Orbitron', monospace;
        --font-body:    'Exo 2', system-ui, sans-serif;
        --font-mono:    'Share Tech Mono', monospace;
      }

      nav {
        top: 0.5rem;
        width: calc(100% - 2rem);
        padding: 0.6rem 1rem;
      }

      .nav-links {
        display: none;
      }

      .nav-controls {
        gap: 0.4rem;
      }

      .hero {
        min-height: auto;
        padding: 6.5rem 0 4rem;
      }

      .problems-grid,
      .services-grid,
      .testimonials-grid,
      .pricing-grid {
        grid-template-columns: 1fr;
      }

      .stats-grid {
        grid-template-columns: repeat(2, 1fr);
      }

      .stat-item {
        border-right: none;
        border-bottom: 1px solid var(--border-2);
      }

      .stat-item:nth-child(odd) {
        border-right: 1px solid var(--border-2);
      }

      .stat-item:nth-last-child(-n+2) {
        border-bottom: none;
      }

      section {
        padding: 4rem 0;
      }

      .trust-bar {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.75rem;
      }
    }

    @media (max-width: 480px) {
      .hero-title {
        font-size: 2rem;
      }

      .stat-value {
        font-size: 2.1rem;
      }
    }