@import url('https://fonts.googleapis.com/css2?family=Plus+Jakarta+Sans:wght@400;500;600;700;800&display=swap');

:root {
  --bg: #0a0d1c; --bg2: #0f1328; --card: rgba(255, 255, 255, .045); --line: rgba(255, 255, 255, .09);
  --text: #eef0fb; --muted: #9aa3c4; --pri: #6366f1; --pri2: #818cf8; --vio: #a78bfa; --cyan: #22d3ee;
  --r: 18px; --nav-h: 68px;
  --font: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; scroll-padding-top: calc(var(--nav-h) + 12px); -webkit-text-size-adjust: 100%; }
body { font-family: var(--font); background: var(--bg); color: var(--text); line-height: 1.6; overflow-x: hidden; -webkit-font-smoothing: antialiased; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
img, svg, canvas { max-width: 100%; }
:focus-visible { outline: 2px solid var(--pri2); outline-offset: 3px; border-radius: 6px; }

.skip { position: fixed; left: 12px; top: -60px; background: #fff; color: #111; padding: 8px 14px; border-radius: 8px; z-index: 300; transition: top .2s; }
.skip:focus { top: 12px; }

/* Nền 3D cố định */
#bg { position: fixed; inset: 0; width: 100%; height: 100%; z-index: 0; display: block; }
.vignette { position: fixed; inset: 0; z-index: 1; pointer-events: none;
  background: radial-gradient(ellipse 80% 60% at 50% 40%, transparent 30%, rgba(10, 13, 28, .65) 100%); }
main, .foot { position: relative; z-index: 2; }
.progress { position: fixed; top: 0; left: 0; height: 3px; width: 100%; z-index: 250; transform: scaleX(0); transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--pri), var(--vio), var(--cyan)); }

.wrap { width: 100%; max-width: 1180px; margin: 0 auto; padding: 0 clamp(18px, 4vw, 32px); }
.wrap.narrow { max-width: 820px; }

/* ===== NAV ===== */
.nav { position: fixed; top: 0; left: 0; right: 0; height: var(--nav-h); z-index: 200; transition: background .3s, border-color .3s, backdrop-filter .3s; border-bottom: 1px solid transparent; padding-top: env(safe-area-inset-top, 0px); box-sizing: content-box; }
.nav.scrolled { background: rgba(10, 13, 28, .72); backdrop-filter: blur(16px) saturate(140%); -webkit-backdrop-filter: blur(16px) saturate(140%); border-color: var(--line); }
.nav-in { max-width: 1180px; height: var(--nav-h); margin: 0 auto; padding: 0 clamp(18px, 4vw, 32px); display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.brand { display: flex; align-items: center; gap: 12px; font-weight: 800; font-size: 1.1rem; letter-spacing: -.02em; }
.logo { width: 36px; height: 36px; border-radius: 10px; display: grid; place-items: center; color: #fff; flex: none;
  background: linear-gradient(135deg, #4f46e5, #8b5cf6); box-shadow: 0 6px 18px rgba(99, 102, 241, .5); }
.logo.sm { width: 28px; height: 28px; border-radius: 8px; }
.links { display: flex; align-items: center; gap: 4px; }
.links > a { padding: 8px 14px; border-radius: 999px; color: var(--muted); font-size: .92rem; font-weight: 500; transition: color .2s, background .2s; }
.links > a:hover { color: #fff; background: rgba(255, 255, 255, .07); }
.links-cta { display: flex; gap: 8px; margin-left: 12px; }
.burger { display: none; width: 42px; height: 42px; border-radius: 12px; border: 1px solid var(--line); background: rgba(255, 255, 255, .05); cursor: pointer; flex-direction: column; align-items: center; justify-content: center; gap: 5px; }
.burger span { width: 18px; height: 2px; background: #fff; border-radius: 2px; transition: transform .25s, opacity .2s; }
.burger[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.burger[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.burger[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ===== BUTTONS ===== */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; padding: 10px 20px; border-radius: 999px; font: inherit; font-weight: 700; font-size: .92rem; cursor: pointer; border: 1px solid transparent; transition: transform .2s, box-shadow .25s, background .2s, border-color .2s; white-space: nowrap; }
.btn.lg { padding: 14px 28px; font-size: 1rem; }
.btn.primary { background: linear-gradient(135deg, #4f46e5, #7c6cf5); color: #fff; box-shadow: 0 8px 24px -6px rgba(99, 102, 241, .7); }
.btn.primary:hover { transform: translateY(-2px); box-shadow: 0 14px 32px -8px rgba(99, 102, 241, .85); }
.btn.ghost { background: rgba(255, 255, 255, .05); border-color: var(--line); color: #fff; }
.btn.ghost:hover { background: rgba(255, 255, 255, .11); border-color: rgba(255, 255, 255, .22); transform: translateY(-2px); }

/* ===== TYPO ===== */
.grad { background: linear-gradient(100deg, #a5b4fc, #c4b5fd 45%, #67e8f9); -webkit-background-clip: text; background-clip: text; color: transparent; }
.eyebrow { display: inline-flex; align-items: center; gap: 8px; padding: 6px 14px; border-radius: 999px; background: rgba(99, 102, 241, .13); border: 1px solid rgba(129, 140, 248, .3); color: #c7d2fe; font-size: .8rem; font-weight: 600; letter-spacing: .02em; }
.eyebrow i { width: 7px; height: 7px; border-radius: 50%; background: var(--cyan); box-shadow: 0 0 10px var(--cyan); animation: pulse 2s ease-in-out infinite; }
@keyframes pulse { 50% { transform: scale(1.5); opacity: .6; } }
h1 { font-size: clamp(2rem, 5.4vw, 3.7rem); line-height: 1.08; letter-spacing: -.035em; font-weight: 800; margin: 20px 0; }
h2 { font-size: clamp(1.7rem, 4.2vw, 2.8rem); line-height: 1.15; letter-spacing: -.03em; font-weight: 800; margin: 16px 0 12px; }
h1, h2 { text-wrap: balance; }
h3 { font-size: 1.12rem; font-weight: 700; letter-spacing: -.01em; margin-bottom: 8px; }
.lead { font-size: clamp(1rem, 1.6vw, 1.18rem); color: var(--muted); max-width: 580px; }

/* ===== HERO ===== */
.hero { min-height: 100vh; min-height: 100svh; display: flex; align-items: center; position: relative; padding: calc(var(--nav-h) + 40px) 0 80px; }
.hero-in { position: relative; display: grid; grid-template-columns: minmax(0, 1.1fr) minmax(0, .9fr); align-items: center; gap: 24px; }
.hero-copy { max-width: 680px; }
.cta { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 30px; }
.cta.center { justify-content: center; }
.trust { display: flex; flex-wrap: wrap; gap: 10px 28px; margin-top: 38px; color: var(--muted); font-size: .88rem; }
.trust b { color: #fff; font-size: 1.25rem; font-weight: 800; margin-right: 4px; }
.hero-float { position: relative; height: 420px; pointer-events: none; }
.chip { position: absolute; display: flex; align-items: center; gap: 10px; padding: 12px 18px; border-radius: 16px; font-size: .88rem; font-weight: 600; white-space: nowrap;
  background: rgba(20, 25, 52, .6); border: 1px solid rgba(255, 255, 255, .14); backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px); box-shadow: 0 18px 40px -16px rgba(0, 0, 0, .6); animation: floaty 7s ease-in-out infinite; }
.chip span { font-size: 1.2rem; }
.chip.c1 { top: 6%; right: 6%; }
.chip.c2 { top: 46%; left: 0; animation-delay: -2.4s; }
.chip.c3 { bottom: 6%; right: 14%; animation-delay: -4.6s; }
@keyframes floaty { 50% { transform: translateY(-16px); } }
.scroll-hint { position: absolute; left: 50%; bottom: 26px; width: 26px; height: 42px; margin-left: -13px; border: 2px solid rgba(255, 255, 255, .3); border-radius: 14px; }
.scroll-hint span { position: absolute; left: 50%; top: 8px; width: 4px; height: 8px; margin-left: -2px; border-radius: 4px; background: #fff; animation: wheel 1.8s ease-in-out infinite; }
@keyframes wheel { 0% { opacity: 0; transform: translateY(0); } 30% { opacity: 1; } 100% { opacity: 0; transform: translateY(14px); } }

/* ===== SECTIONS ===== */
.sec { padding: clamp(64px, 10vw, 120px) 0; position: relative; }
.sec-head { text-align: center; max-width: 720px; margin: 0 auto clamp(36px, 6vw, 60px); }
.sec-head p { color: var(--muted); font-size: 1.05rem; }
.grid { display: grid; gap: 18px; }
.feat { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.skills { grid-template-columns: repeat(4, minmax(0, 1fr)); }

.card, .skill { position: relative; background: var(--card); border: 1px solid var(--line); border-radius: var(--r); padding: 26px; overflow: hidden;
  backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px); transition: border-color .3s, background .3s, box-shadow .3s; transform-style: preserve-3d; }
.card::before, .skill::before { content: ''; position: absolute; inset: 0; opacity: 0; transition: opacity .3s; pointer-events: none;
  background: radial-gradient(420px circle at var(--mx, 50%) var(--my, 0%), hsla(var(--h, 239), 90%, 70%, .16), transparent 45%); }
.skill::before { background: radial-gradient(360px circle at var(--mx, 50%) var(--my, 0%), color-mix(in srgb, var(--c) 28%, transparent), transparent 50%); }
.card:hover, .skill:hover { border-color: rgba(255, 255, 255, .22); background: rgba(255, 255, 255, .07); box-shadow: 0 24px 50px -24px rgba(0, 0, 0, .7); }
.card:hover::before, .skill:hover::before { opacity: 1; }
.card p, .skill p { color: var(--muted); font-size: .94rem; }
.ico { width: 48px; height: 48px; border-radius: 14px; display: grid; place-items: center; font-size: 1.4rem; margin-bottom: 18px;
  background: hsla(var(--h, 239), 85%, 65%, .16); border: 1px solid hsla(var(--h, 239), 85%, 70%, .3); }
.skill { border-top: 3px solid var(--c); }
.s-ico { display: grid; place-items: center; width: 52px; height: 52px; border-radius: 16px; font-size: 1.5rem; margin-bottom: 16px; background: color-mix(in srgb, var(--c) 18%, transparent); }
.note-line { text-align: center; color: var(--muted); margin-top: 32px; font-size: .98rem; }
.note-line b { color: #fff; }

/* ===== PREVIEW MOCK ===== */
.mock { max-width: 900px; margin: 0 auto; border-radius: 20px; overflow: hidden; border: 1px solid rgba(255, 255, 255, .14); background: #12162b; box-shadow: 0 50px 100px -30px rgba(0, 0, 0, .8), 0 0 80px -20px rgba(99, 102, 241, .45); transform: perspective(1400px) rotateX(var(--rx, 8deg)) scale(var(--sc, .96)); transition: transform .15s linear; will-change: transform; }
.mock-bar { display: flex; align-items: center; gap: 7px; padding: 12px 16px; background: #0b0e20; border-bottom: 1px solid var(--line); }
.mock-bar i { width: 11px; height: 11px; border-radius: 50%; background: #ef4444; }
.mock-bar i:nth-child(2) { background: #f59e0b; } .mock-bar i:nth-child(3) { background: #22c55e; }
.mock-bar span { margin-left: 12px; font-size: .74rem; color: var(--muted); }
.mock-body { display: grid; grid-template-columns: 170px minmax(0, 1fr); min-height: 300px; }
.m-side { background: #0a0d1c; padding: 16px 12px; display: flex; flex-direction: column; gap: 4px; font-size: .78rem; color: #8a93b8; }
.m-brand { color: #fff; font-size: .85rem; padding: 4px 8px 12px; }
.m-side span { padding: 8px 10px; border-radius: 8px; }
.m-side .on { background: rgba(129, 140, 248, .18); color: #fff; box-shadow: inset 3px 0 0 #818cf8; }
.m-main { padding: 22px; background: #f5f6fb; color: #1e293b; }
.m-hello { font-weight: 800; font-size: 1.15rem; margin-bottom: 16px; }
.m-row { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 10px; margin-bottom: 10px; }
.m-tile { background: #fff; border: 1px solid #e6e8f0; border-radius: 12px; padding: 14px; font-size: 1.3rem; display: flex; flex-direction: column; gap: 4px; }
.m-tile small { font-size: .72rem; font-weight: 700; color: #475569; }
.m-panel { background: #fff; border: 1px solid #e6e8f0; border-radius: 12px; padding: 14px; display: flex; flex-direction: column; gap: 8px; justify-content: center; }
.m-panel i { height: 8px; border-radius: 4px; background: #e6e8f0; } .m-panel i:nth-child(1) { width: 70%; background: #c7d2fe; } .m-panel i:nth-child(3) { width: 45%; }
.m-stat { border-radius: 12px; padding: 14px; color: #fff; display: flex; flex-direction: column; }
.m-stat b { font-size: 1.6rem; line-height: 1.1; } .m-stat small { font-size: .7rem; opacity: .85; }
.m-stat.s1 { background: linear-gradient(135deg, #4f46e5, #6366f1); } .m-stat.s2 { background: linear-gradient(135deg, #334155, #475569); }

/* ===== STEPS ===== */
.steps { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 18px; counter-reset: s; position: relative; }
.step { position: relative; padding: 28px 24px; border-radius: var(--r); background: var(--card); border: 1px solid var(--line); }
.step .n { display: grid; place-items: center; width: 44px; height: 44px; border-radius: 14px; font-weight: 800; font-size: 1.1rem; margin-bottom: 18px; background: linear-gradient(135deg, #4f46e5, #8b5cf6); box-shadow: 0 8px 20px -6px rgba(99, 102, 241, .7); }
.step p { color: var(--muted); font-size: .94rem; }

/* ===== STATS ===== */
.stats-sec { padding: clamp(36px, 6vw, 60px) 0; }
.stats { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); border: 1px solid var(--line); border-radius: 22px; background: linear-gradient(135deg, rgba(79, 70, 229, .16), rgba(139, 92, 246, .08)); backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px); }
.stat { padding: 30px 16px; text-align: center; border-right: 1px solid var(--line); }
.stat:last-child { border-right: none; }
.stat b { display: block; font-size: clamp(2rem, 4.5vw, 3rem); font-weight: 800; letter-spacing: -.03em; line-height: 1.1; background: linear-gradient(120deg, #fff, #c7d2fe); -webkit-background-clip: text; background-clip: text; color: transparent; }
.stat span { color: var(--muted); font-size: .88rem; }

/* ===== FAQ ===== */
.faq { display: flex; flex-direction: column; gap: 12px; }
.faq details { border-radius: 16px; background: var(--card); border: 1px solid var(--line); transition: border-color .25s, background .25s; }
.faq details[open] { border-color: rgba(129, 140, 248, .4); background: rgba(99, 102, 241, .07); }
.faq summary { cursor: pointer; list-style: none; padding: 18px 54px 18px 22px; font-weight: 600; position: relative; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: '+'; position: absolute; right: 22px; top: 50%; transform: translateY(-50%); font-size: 1.5rem; font-weight: 400; color: var(--pri2); transition: transform .25s; }
.faq details[open] summary::after { transform: translateY(-50%) rotate(45deg); }
.faq p { padding: 0 22px 20px; color: var(--muted); }

/* ===== CTA + FOOTER ===== */
.cta-box { text-align: center; padding: clamp(40px, 7vw, 76px) clamp(20px, 5vw, 48px); border-radius: 28px; border: 1px solid rgba(129, 140, 248, .3); position: relative; overflow: hidden;
  background: radial-gradient(600px 300px at 50% 0%, rgba(99, 102, 241, .32), transparent 70%), rgba(255, 255, 255, .04); }
.cta-box p { color: var(--muted); max-width: 520px; margin: 0 auto; }
.foot { border-top: 1px solid var(--line); background: rgba(10, 13, 28, .85); padding: 28px 0 calc(28px + env(safe-area-inset-bottom, 0px)); }
.foot-in { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 16px 28px; }
.foot nav { display: flex; flex-wrap: wrap; gap: 8px 22px; color: var(--muted); font-size: .9rem; }
.foot nav a:hover { color: #fff; }
.foot small { color: var(--muted); }

/* ===== REVEAL ===== */
.reveal { opacity: 0; transform: translateY(28px); transition: opacity .8s cubic-bezier(.2, .7, .2, 1), transform .8s cubic-bezier(.2, .7, .2, 1); }
.reveal.in { opacity: 1; transform: none; }
.reveal.d1 { transition-delay: .1s; } .reveal.d2 { transition-delay: .2s; } .reveal.d3 { transition-delay: .3s; } .reveal.d4 { transition-delay: .4s; }
.no-js .reveal { opacity: 1; transform: none; }

/* ===== RESPONSIVE ===== */
@media (max-width: 1100px) {
  .feat { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .skills { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 880px) {
  .burger { display: flex; }
  .links { position: fixed; top: calc(var(--nav-h) + env(safe-area-inset-top, 0px)); left: 12px; right: 12px; flex-direction: column; align-items: stretch; gap: 2px; padding: 14px;
    background: rgba(12, 16, 36, .96); backdrop-filter: blur(18px); -webkit-backdrop-filter: blur(18px); border: 1px solid var(--line); border-radius: 20px; box-shadow: 0 30px 60px -20px rgba(0, 0, 0, .8);
    opacity: 0; transform: translateY(-10px) scale(.98); pointer-events: none; transition: opacity .2s, transform .2s; }
  .links.open { opacity: 1; transform: none; pointer-events: auto; }
  .links > a { padding: 13px 16px; font-size: 1rem; border-radius: 12px; }
  .links-cta { margin: 8px 0 0; flex-direction: column; }
  .links-cta .btn { width: 100%; padding: 13px; }
  .hero { align-items: flex-start; min-height: auto; padding-bottom: 110px; }
  .hero-in { grid-template-columns: 1fr; }
  .hero-float { display: none; }
  .hero-copy { max-width: none; text-align: center; margin: 0 auto; }
  .lead { margin: 0 auto; }
  .cta { justify-content: center; }
  .trust { justify-content: center; }
  .steps { grid-template-columns: 1fr; }
  .stats { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .stat:nth-child(2) { border-right: none; }
  .stat:nth-child(-n+2) { border-bottom: 1px solid var(--line); }
  .mock-body { grid-template-columns: 1fr; }
  .m-side { display: none; }
}
@media (max-width: 560px) {
  .feat, .skills { grid-template-columns: 1fr; }
  .btn.lg { width: 100%; }
  .cta { flex-direction: column; }
  .card, .skill { padding: 22px; }
  .m-row { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .m-row .m-tile:nth-child(3), .m-row .m-panel { display: none; }
  .scroll-hint { display: none; }
  .foot-in { flex-direction: column; align-items: flex-start; }
}
@media (max-height: 560px) and (orientation: landscape) { .hero { min-height: auto; } .scroll-hint { display: none; } }
@media (hover: none) { .card:hover, .skill:hover { background: var(--card); box-shadow: none; } }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
  .reveal { opacity: 1; transform: none; }
}