/* =========================================================
   Nhà Chung Landing — site.css
   Contract: only styling. No routing/API changes.
   Tone: premium minimal, beige + muted green + black.
   ========================================================= */

/* --------- Reset / Base --------- */
*,
*::before,
*::after { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; scroll-behavior: smooth; }
body { margin: 0; }

img, svg, video { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; background: none; border: 0; padding: 0; cursor: pointer; }
:focus-visible { outline: 2px solid rgba(130, 255, 186, .55); outline-offset: 3px; border-radius: 10px; }

.sr-only{
  position:absolute;width:1px;height:1px;padding:0;margin:-1px;
  overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0
}

/* --------- Theme Tokens --------- */
:root{
  --bg: #0b0f0c;
  --fg: #eef2ea;
  --muted: rgba(238,242,234,.72);
  --muted2: rgba(238,242,234,.58);

  --beige: #f2efe8;
  --green: #4fe08c;
  --green2: #2bb36a;

  --border: rgba(255,255,255,.12);
  --border2: rgba(255,255,255,.16);

  --card: rgba(255,255,255,.06);
  --card2: rgba(255,255,255,.085);

  --shadow: 0 24px 80px rgba(0,0,0,.55);
  --shadow2: 0 10px 40px rgba(0,0,0,.35);

  --blur: blur(14px);
  --radius: 22px;
  --radius2: 16px;

  --max: 1160px;
  --pad: clamp(16px, 3.2vw, 28px);

  --h1: clamp(40px, 5vw, 72px);
  --h2: clamp(28px, 3.2vw, 44px);
  --h3: 18px;
  --lead: clamp(16px, 1.6vw, 18px);
  --text: 16px;

  --lh: 1.6;

  --gradA: radial-gradient(1100px 700px at 20% 0%, rgba(79,224,140,.14), transparent 55%);
  --gradB: radial-gradient(900px 680px at 82% 18%, rgba(242,239,232,.08), transparent 55%);
  --gradC: radial-gradient(900px 680px at 50% 120%, rgba(79,224,140,.09), transparent 50%);
  --grid: linear-gradient(rgba(255,255,255,.06) 1px, transparent 1px),
          linear-gradient(90deg, rgba(255,255,255,.05) 1px, transparent 1px);

  --gridSize: 72px;
}

html[data-theme="light"]{
  --bg: #f2efe8;
  --fg: #0b0f0c;
  --muted: rgba(11,15,12,.72);
  --muted2: rgba(11,15,12,.58);
  --border: rgba(0,0,0,.10);
  --border2: rgba(0,0,0,.12);
  --card: rgba(255,255,255,.65);
  --card2: rgba(255,255,255,.78);
  --shadow: 0 22px 64px rgba(0,0,0,.14);
  --shadow2: 0 10px 28px rgba(0,0,0,.10);

  --gradA: radial-gradient(1100px 700px at 18% 0%, rgba(79,224,140,.20), transparent 60%);
  --gradB: radial-gradient(900px 680px at 85% 15%, rgba(11,15,12,.06), transparent 60%);
  --gradC: radial-gradient(900px 680px at 50% 120%, rgba(79,224,140,.14), transparent 55%);
  --grid: linear-gradient(rgba(0,0,0,.06) 1px, transparent 1px),
          linear-gradient(90deg, rgba(0,0,0,.05) 1px, transparent 1px);
}

/* --------- Body / Background --------- */
body{
  background: var(--bg);
  color: var(--fg);
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Arial, "Apple Color Emoji", "Segoe UI Emoji";
  line-height: var(--lh);
  overflow-x: hidden;
}

body::before{
  content:"";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background:
    var(--gradA),
    var(--gradB),
    var(--gradC),
    var(--grid);
  background-size: auto, auto, auto, var(--gridSize) var(--gridSize);
  opacity: .95;
  z-index: -2;
}

body::after{
  content:"";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background: radial-gradient(800px 520px at 50% 30%, rgba(0,0,0,.12), transparent 60%);
  z-index: -1;
}

/* --------- Layout helpers --------- */
.nc-main{ min-height: 100dvh; padding-top: 92px; }
@media (max-width: 860px){ .nc-main{ padding-top: 78px; } }

.nc-section{ padding: clamp(44px, 6vw, 92px) 0; }
.nc-section__inner{
  width: min(var(--max), calc(100% - var(--pad)*2));
  margin: 0 auto;
}

.nc-section--cta{ padding-top: 28px; padding-bottom: 92px; }
.nc-section--legal{ padding-top: 24px; padding-bottom: 24px; }

.nc-h1{ font-size: var(--h1); letter-spacing: -0.02em; line-height: 1.08; margin: 14px 0 14px; }
.nc-h2{ font-size: var(--h2); letter-spacing: -0.015em; line-height: 1.14; margin: 0 0 16px; }
.nc-h3{ font-size: var(--h3); letter-spacing: -0.01em; margin: 0 0 10px; }
.nc-text{ font-size: var(--text); color: var(--muted); margin: 0 0 14px; }
.nc-text--muted{ color: var(--muted2); }
.nc-lead{ font-size: var(--lead); color: var(--muted); margin: 0 0 18px; }
.nc-kicker{ color: var(--muted2); text-transform: none; letter-spacing: .02em; margin: 0 0 10px; }

/* --------- Links (no raw ugly links) --------- */
.nc-link{
  color: var(--fg);
  text-decoration: underline;
  text-decoration-color: rgba(79,224,140,.35);
  text-underline-offset: 5px;
  text-decoration-thickness: 1px;
  transition: text-decoration-color .2s ease, color .2s ease, opacity .2s ease;
}
.nc-link:hover{
  color: rgba(79,224,140,.98);
  text-decoration-color: rgba(79,224,140,.75);
}
.nc-link:active{ opacity: .88; }

/* --------- Buttons --------- */
.nc-btn{
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 11px 14px;
  border-radius: 999px;
  border: 1px solid var(--border2);
  background: rgba(79,224,140,.12);
  color: var(--fg);
  box-shadow: 0 10px 30px rgba(0,0,0,.22);
  transition: transform .18s ease, background .18s ease, border-color .18s ease, box-shadow .18s ease, opacity .18s ease;
  user-select: none;
  white-space: nowrap;
}
.nc-btn:hover{
  transform: translateY(-1px);
  background: rgba(79,224,140,.18);
  border-color: rgba(79,224,140,.35);
  box-shadow: 0 16px 44px rgba(0,0,0,.28);
}
.nc-btn:active{ transform: translateY(0px); opacity: .92; }
.nc-btn--ghost{
  background: rgba(255,255,255,.04);
  border-color: var(--border);
  box-shadow: none;
}
.nc-btn--ghost:hover{
  background: rgba(255,255,255,.07);
  border-color: rgba(255,255,255,.22);
  box-shadow: 0 14px 40px rgba(0,0,0,.22);
}
.nc-btn--xl{ padding: 14px 18px; font-size: 16px; }
.nc-btn--xl:hover{ transform: translateY(-2px); }

.nc-btn--ghost.nc-btn--xl{ padding: 14px 18px; }

/* --------- Topbar / Navigation --------- */
.nc-topbar{
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 50;
  backdrop-filter: var(--blur);
  -webkit-backdrop-filter: var(--blur);
  background: linear-gradient(to bottom, rgba(0,0,0,.55), rgba(0,0,0,.26));
  border-bottom: 1px solid rgba(255,255,255,.10);
}
html[data-theme="light"] .nc-topbar{
  background: linear-gradient(to bottom, rgba(242,239,232,.92), rgba(242,239,232,.70));
  border-bottom: 1px solid rgba(0,0,0,.10);
}

.nc-topbar__inner{
  width: min(var(--max), calc(100% - var(--pad)*2));
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 0;
}

.nc-brand{
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-width: 220px;
}
.nc-logo{
  width: 40px;
  height: 40px;
  border-radius: 14px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  letter-spacing: .02em;
  background: rgba(255,255,255,.06);
  border: 1px solid var(--border2);
  box-shadow: var(--shadow2);
}
.nc-brand__text{ display: grid; }
.nc-brand__name{ font-weight: 700; line-height: 1.1; }
.nc-brand__tag{ color: var(--muted2); font-size: 12px; margin-top: 2px; }

.nc-nav{
  display: flex;
  align-items: center;
  gap: 18px;
  margin-left: 10px;
  flex: 1;
}
.nc-nav__link{
  position: relative;
  font-size: 14px;
  color: var(--muted);
  padding: 10px 6px;
  border-radius: 10px;
  transition: color .18s ease, background .18s ease;
}
.nc-nav__link::after{
  content:"";
  position: absolute;
  left: 8px; right: 8px; bottom: 6px;
  height: 2px;
  border-radius: 999px;
  background: rgba(79,224,140,.0);
  transform: scaleX(.2);
  transform-origin: center;
  transition: transform .22s ease, background .22s ease;
}
.nc-nav__link:hover{
  color: var(--fg);
  background: rgba(255,255,255,.05);
}
.nc-nav__link:hover::after{
  background: rgba(79,224,140,.72);
  transform: scaleX(1);
}

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

/* Language dropdown */
.nc-lang{ position: relative; }
.nc-lang__btn{
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: rgba(255,255,255,.04);
  transition: background .18s ease, border-color .18s ease, transform .18s ease;
}
.nc-lang__btn:hover{ background: rgba(255,255,255,.07); border-color: rgba(255,255,255,.22); transform: translateY(-1px); }
.nc-lang__chev{ opacity: .8; }

.nc-lang__menu{
  position: absolute;
  right: 0;
  top: calc(100% + 10px);
  min-width: 190px;
  padding: 8px;
  border-radius: 14px;
  border: 1px solid var(--border2);
  background: rgba(20,24,21,.72);
  backdrop-filter: var(--blur);
  -webkit-backdrop-filter: var(--blur);
  box-shadow: var(--shadow);
}
html[data-theme="light"] .nc-lang__menu{
  background: rgba(255,255,255,.86);
}
.nc-lang__item{
  width: 100%;
  text-align: left;
  padding: 10px 10px;
  border-radius: 12px;
  border: 1px solid transparent;
  color: var(--fg);
  transition: background .16s ease, border-color .16s ease;
}
.nc-lang__item:hover{ background: rgba(79,224,140,.12); border-color: rgba(79,224,140,.26); }
.nc-lang__item[aria-selected="true"]{
  background: rgba(79,224,140,.16);
  border-color: rgba(79,224,140,.30);
}

/* Burger + mobile menu */
.nc-burger{
  display: none;
  width: 44px;
  height: 44px;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: rgba(255,255,255,.04);
  align-items: center;
  justify-content: center;
  gap: 6px;
  flex-direction: column;
}
.nc-burger span{
  width: 18px;
  height: 2px;
  background: rgba(238,242,234,.86);
  border-radius: 999px;
}
html[data-theme="light"] .nc-burger span{ background: rgba(11,15,12,.78); }

.nc-mobile{
  width: min(var(--max), calc(100% - var(--pad)*2));
  margin: 0 auto 12px;
  padding: 12px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: rgba(255,255,255,.04);
  backdrop-filter: var(--blur);
  -webkit-backdrop-filter: var(--blur);
}
.nc-mobile__link{
  display: block;
  padding: 12px 12px;
  border-radius: 14px;
  color: var(--muted);
  border: 1px solid transparent;
  transition: background .16s ease, border-color .16s ease, color .16s ease;
}
.nc-mobile__link:hover{
  background: rgba(255,255,255,.06);
  border-color: rgba(255,255,255,.14);
  color: var(--fg);
}
.nc-mobile__cta{ display: flex; gap: 10px; padding: 10px 8px 4px; }

/* Responsive nav switch */
@media (max-width: 980px){
  .nc-brand{ min-width: auto; }
  .nc-brand__tag{ display: none; }
}
@media (max-width: 860px){
  .nc-nav{ display: none; }
  .nc-actions{ gap: 8px; }
  .nc-burger{ display: inline-flex; }
  .nc-topbar__inner{ padding: 10px 0; }
  .nc-logo{ width: 38px; height: 38px; border-radius: 14px; }
}
@media (max-width: 520px){
  .nc-actions a.nc-btn--ghost{ display: none; } /* keep UI clean on very small screens */
  .nc-actions a.nc-btn{ padding: 10px 12px; }
}

/* --------- Hero --------- */
.nc-hero{ padding: clamp(32px, 5vw, 68px) 0 0; }
.nc-hero__inner{
  width: min(var(--max), calc(100% - var(--pad)*2));
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.15fr .85fr;
  gap: clamp(18px, 3vw, 34px);
  align-items: start;
}

.nc-hero__copy{ padding-top: 10px; }
.nc-hero__cta{ display: flex; gap: 12px; flex-wrap: wrap; margin: 18px 0 16px; }

.nc-badges{ display: flex; gap: 10px; flex-wrap: wrap; margin-top: 10px; }
.nc-badge{
  display: inline-flex;
  align-items: center;
  padding: 9px 12px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: rgba(255,255,255,.04);
  color: var(--muted);
  font-size: 13px;
}

.nc-hero__panel{ position: sticky; top: 98px; }
@media (max-width: 860px){
  .nc-hero__inner{ grid-template-columns: 1fr; }
  .nc-hero__panel{ position: relative; top: auto; }
}

/* --------- Cards / Glass --------- */
.nc-card, .nc-panel, .nc-module, .nc-level, .nc-rm{
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--card);
  backdrop-filter: var(--blur);
  -webkit-backdrop-filter: var(--blur);
  box-shadow: var(--shadow2);
}

.nc-card{ padding: 18px; }
.nc-card--glass{
  background: rgba(255,255,255,.07);
  border-color: rgba(255,255,255,.14);
  box-shadow: 0 18px 60px rgba(0,0,0,.35);
}

.nc-panel{ padding: 18px; }
.nc-panel__head{ display: flex; align-items: baseline; justify-content: space-between; gap: 12px; margin-bottom: 14px; }
.nc-panel__title{ font-weight: 700; }
.nc-panel__hint{ color: var(--muted2); font-size: 13px; }
.nc-panel__foot{ display: flex; gap: 10px; flex-wrap: wrap; margin-top: 14px; }

/* Triplet items (no raw link block) */
.nc-triplet{ display: grid; gap: 12px; }
.nc-triplet__item{
  border-radius: var(--radius2);
  border: 1px solid var(--border);
  background: rgba(0,0,0,.12);
  padding: 14px;
}
html[data-theme="light"] .nc-triplet__item{ background: rgba(0,0,0,.04); }
.nc-triplet__k{ font-weight: 700; }
.nc-triplet__v{ color: var(--muted); margin-top: 2px; font-size: 14px; }
.nc-triplet__a{ margin-top: 10px; }
.nc-triplet__a a{ font-size: 14px; }

/* --------- Lists / Pills / Steps --------- */
.nc-list{
  margin: 0;
  padding-left: 18px;
  color: var(--muted);
}
.nc-list li{ margin: 8px 0; }

.nc-steps{
  margin: 0;
  padding-left: 18px;
  color: var(--muted);
}
.nc-steps li{ margin: 8px 0; }

.nc-pills{ display: flex; gap: 10px; flex-wrap: wrap; margin-top: 10px; }
.nc-pill{
  display: inline-flex;
  align-items: center;
  padding: 10px 12px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: rgba(255,255,255,.04);
  color: var(--fg);
  font-size: 13px;
}

/* --------- Multi-column blocks --------- */
.nc-3col{
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
  margin-top: 16px;
}
@media (max-width: 960px){
  .nc-3col{ grid-template-columns: 1fr; }
}

/* Two column grid in features */
.nc-grid2{
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
  margin-top: 16px;
}
@media (max-width: 960px){
  .nc-grid2{ grid-template-columns: 1fr; }
}

/* --------- Architecture block --------- */
.nc-arch{
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 14px;
  align-items: stretch;
  margin-top: 16px;
}
.nc-arch__mid{
  display: grid;
  place-items: center;
  padding: 10px 6px;
}
.nc-arch__line{
  width: 2px;
  height: 100%;
  background: linear-gradient(to bottom, transparent, rgba(79,224,140,.55), transparent);
  border-radius: 999px;
}
.nc-arch__node{
  width: 44px; height: 44px;
  border-radius: 16px;
  display: grid;
  place-items: center;
  border: 1px solid rgba(79,224,140,.28);
  background: rgba(79,224,140,.10);
  margin: 10px 0;
}
.nc-arch__links{
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-top: 10px;
  align-items: center;
}
.nc-dot{ opacity: .55; }

@media (max-width: 980px){
  .nc-arch{ grid-template-columns: 1fr; }
  .nc-arch__mid{ display: none; }
}

/* Contract callout */
.nc-callout{
  margin-top: 16px;
  border-radius: var(--radius);
  border: 1px solid rgba(79,224,140,.20);
  background: rgba(79,224,140,.08);
  padding: 16px;
}
.nc-callout__title{ font-weight: 700; margin-bottom: 8px; }
.nc-callout__body{
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  align-items: center;
  color: var(--muted);
}
.nc-callout__body code{
  padding: 2px 8px;
  border-radius: 999px;
  background: rgba(0,0,0,.14);
  border: 1px solid var(--border);
  color: var(--fg);
}
html[data-theme="light"] .nc-callout__body code{ background: rgba(0,0,0,.05); }
.nc-callout__hint{ margin-top: 8px; color: var(--muted2); font-size: 13px; }

/* --------- Modules grid --------- */
.nc-modules{
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
  margin-top: 16px;
}
.nc-module{ padding: 16px; }
.nc-module:hover{
  border-color: rgba(79,224,140,.28);
  background: rgba(255,255,255,.08);
  transform: translateY(-1px);
  transition: transform .18s ease, background .18s ease, border-color .18s ease;
}
@media (max-width: 960px){
  .nc-modules{ grid-template-columns: 1fr; }
}

.nc-section__cta{
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 16px;
}

/* --------- Levels --------- */
.nc-levels{
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 12px;
  margin-top: 16px;
}
.nc-level{
  padding: 14px;
  border-radius: var(--radius);
}
.nc-level__n{
  display: inline-flex;
  padding: 6px 10px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: rgba(255,255,255,.04);
  color: var(--muted);
  font-weight: 700;
  font-size: 12px;
}
.nc-level__t{ margin-top: 10px; font-weight: 700; }
.nc-level__d{ margin-top: 6px; color: var(--muted); font-size: 14px; }
@media (max-width: 1100px){
  .nc-levels{ grid-template-columns: 1fr 1fr; }
}
@media (max-width: 560px){
  .nc-levels{ grid-template-columns: 1fr; }
}

/* --------- Roadmap --------- */
.nc-roadmap{
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
  margin-top: 16px;
}
.nc-rm{ padding: 16px; }
.nc-rm__k{
  width: 52px; height: 52px;
  border-radius: 18px;
  display: grid;
  place-items: center;
  font-weight: 900;
  background: rgba(79,224,140,.12);
  border: 1px solid rgba(79,224,140,.22);
  box-shadow: 0 10px 30px rgba(0,0,0,.22);
}
.nc-rm__t{ margin-top: 10px; font-weight: 800; }
@media (max-width: 960px){
  .nc-roadmap{ grid-template-columns: 1fr; }
}

/* --------- FAQ --------- */
.nc-faq{ display: grid; gap: 12px; margin-top: 16px; }
.nc-faq__item{
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: rgba(255,255,255,.04);
  padding: 14px;
}
.nc-faq__q{
  cursor: pointer;
  font-weight: 700;
  color: var(--fg);
  list-style: none;
}
.nc-faq__q::-webkit-details-marker{ display: none; }
.nc-faq__a{
  margin-top: 10px;
  color: var(--muted);
  padding-left: 2px;
}

/* --------- CTA box --------- */
.nc-ctaBox{
  display: grid;
  grid-template-columns: 1.2fr .8fr;
  gap: 16px;
  align-items: center;
  padding: 18px;
  border-radius: var(--radius);
  border: 1px solid rgba(79,224,140,.22);
  background: linear-gradient(180deg, rgba(79,224,140,.12), rgba(255,255,255,.03));
  box-shadow: var(--shadow);
}
.nc-ctaBox__btns{
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  justify-content: flex-end;
}
@media (max-width: 960px){
  .nc-ctaBox{ grid-template-columns: 1fr; }
  .nc-ctaBox__btns{ justify-content: flex-start; }
}

/* --------- Legal strip & Footer --------- */
.nc-legal{
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  padding: 12px 0;
}
.nc-legal__brand{ font-weight: 800; }
.nc-legal__muted{ color: var(--muted2); font-size: 13px; }

.nc-footer{
  border-top: 1px solid var(--border);
  padding: 16px 0;
}
.nc-footer__inner{
  width: min(var(--max), calc(100% - var(--pad)*2));
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  color: var(--muted);
}
.nc-footer__muted{ color: var(--muted2); font-size: 13px; }

/* --------- Small polish --------- */
pre, code{ font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace; }