/* ===========================================================================
   TwoNest — trang giới thiệu, dựng như một cuốn sổ dán ảnh.
   Nền mận tối lấy từ dark mode của app (palette.dart), thẻ là giấy kem dán
   băng keo, ảnh là ảnh THẬT của app render bằng tool/site_shots.dart.
   Font: Nunito (tiêu đề) · Plus Jakarta Sans (chữ thường) · Patrick Hand
   (viết tay) — đúng bộ app đang dùng, đủ tiếng Việt.
   =========================================================================== */

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

:root{
  --ink:#F7EFF6;
  --ink-dim:#C4B2CD;
  --plum:#150B1D;
  --rose:#F0559B;
  --rose-deep:#BE185D;
  --violet:#A78BFA;
  --gold:#F6C667;
  --paper:#FBF3E4;
  --paper-2:#F1E5CE;
  --paper-ink:#3B0A24;
  --paper-ink-dim:#6A4257;
  --tape:rgba(246,198,103,.42);
  --space:clamp(52px,7vw,96px);
  --maxw:1180px;
}

html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{
  background:var(--plum);color:var(--ink);
  font-family:"Plus Jakarta Sans",system-ui,-apple-system,"Segoe UI",sans-serif;
  font-size:17px;line-height:1.6;overflow-x:hidden;position:relative;
}
img{max-width:100%;height:auto;display:block}
.sprite{display:none}

h1,h2,h3{font-family:Nunito,system-ui,sans-serif;line-height:1.08;
  letter-spacing:-.02em;text-wrap:balance}
h1{font-size:clamp(42px,7vw,84px);font-weight:900}
h2{font-size:clamp(29px,4.4vw,50px);font-weight:900}
h3{font-size:clamp(20px,2.2vw,25px);font-weight:800;letter-spacing:-.01em}
p{text-wrap:pretty}
a{color:var(--rose)}
.hand{font-family:"Patrick Hand",cursive;font-weight:400;letter-spacing:.01em}

.wrap{width:100%;max-width:var(--maxw);margin:0 auto;padding:0 22px}
.section{position:relative;z-index:2;padding:var(--space) 0}
.lead{color:var(--ink-dim);font-size:clamp(16px,1.55vw,19px);max-width:56ch}

.skip{position:absolute;left:0;top:0;z-index:99;background:var(--paper);
  color:var(--paper-ink);padding:12px 18px;font-weight:700;border-radius:0 0 12px 0;
  transform:translateY(-140%)}
.skip:focus{transform:none}
:where(a,button,summary):focus-visible{outline:3px solid var(--gold);
  outline-offset:3px;border-radius:10px}

/* ── Nền: quầng aurora nhạt + hạt giấy + mưa tim ─────────────────────── */
.bg{position:fixed;inset:0;z-index:0;pointer-events:none;
  background:
    radial-gradient(60% 50% at 78% 6%, rgba(167,139,250,.26), transparent 70%),
    radial-gradient(55% 45% at 10% 20%, rgba(240,85,155,.22), transparent 70%),
    radial-gradient(70% 60% at 50% 104%, rgba(246,198,103,.13), transparent 70%),
    linear-gradient(180deg,#150B1D 0%,#1E1129 45%,#150B1D 100%)}
.grain{position:fixed;inset:0;z-index:1;pointer-events:none;opacity:.3;
  mix-blend-mode:overlay;
  background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.85' numOctaves='3'/%3E%3C/filter%3E%3Crect width='160' height='160' filter='url(%23n)' opacity='.5'/%3E%3C/svg%3E")}
#hearts{position:fixed;inset:0;z-index:1;pointer-events:none}

/* ── Sợi chỉ nét đứt chạy dọc trang ──────────────────────────────────── */
.thread{position:absolute;left:50%;top:0;height:100%;width:3px;z-index:1;
  transform:translateX(-50%);pointer-events:none;display:none}
.thread svg{height:100%;width:100%;overflow:visible}
.thread path{fill:none;stroke:rgba(246,198,103,.45);stroke-width:2;
  stroke-dasharray:9 12;stroke-linecap:round}

/* ── Nút ─────────────────────────────────────────────────────────────── */
.icon{width:20px;height:20px;flex:none;fill:none;stroke:currentColor;
  stroke-width:2;stroke-linecap:round;stroke-linejoin:round}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:10px;
  min-height:52px;padding:14px 26px;border-radius:999px;border:1px solid transparent;
  font:inherit;font-weight:800;text-decoration:none;cursor:pointer;
  transition:transform .18s cubic-bezier(.2,.9,.3,1.25),box-shadow .22s ease}
.btn-primary{color:#1B0A16;
  background:linear-gradient(135deg,var(--gold),var(--rose) 58%,var(--violet));
  box-shadow:0 16px 34px -16px rgba(240,85,155,.9)}
.btn-primary:hover{transform:translateY(-2px) rotate(-.6deg);
  box-shadow:0 22px 44px -18px rgba(240,85,155,1)}
.btn-primary:active{transform:translateY(0) scale(.98)}
.btn-ghost{color:var(--ink);background:rgba(255,255,255,.06);
  border-color:rgba(255,255,255,.2)}
.btn-ghost:hover{transform:translateY(-2px);background:rgba(255,255,255,.11)}
.btn .icon{width:18px;height:18px;fill:currentColor;stroke:none}
.btn-sm{min-height:42px;padding:10px 18px;font-size:15px}
.icon-btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;
  min-width:44px;min-height:44px;padding:0 12px;border-radius:999px;
  background:rgba(255,255,255,.07);border:1px solid rgba(255,255,255,.18);
  color:var(--ink);font:inherit;font-size:13px;font-weight:800;cursor:pointer;
  transition:background-color .2s ease,transform .18s ease}
.icon-btn:hover{background:rgba(255,255,255,.13);transform:translateY(-1px)}
.icon-btn .icon{width:17px;height:17px}

/* ── Chọn ngôn ngữ (17 ngôn ngữ như app) ─────────────────────────────── */
.lang-wrap{position:relative}
.lang-menu{position:absolute;top:calc(100% + 8px);inset-inline-end:0;z-index:40;
  list-style:none;min-width:220px;max-height:min(70vh,470px);overflow-y:auto;
  padding:6px;border-radius:18px;background:rgba(28,14,38,.97);
  border:1px solid rgba(255,255,255,.16);
  box-shadow:0 24px 50px -18px rgba(0,0,0,.85);
  -webkit-backdrop-filter:blur(14px);backdrop-filter:blur(14px)}
.lang-menu[hidden]{display:none}
.lang-menu button{display:flex;align-items:center;justify-content:space-between;gap:14px;
  width:100%;min-height:42px;padding:9px 12px;border:0;border-radius:12px;
  background:none;color:var(--ink);font:inherit;font-size:15px;font-weight:600;
  text-align:start;cursor:pointer;transition:background-color .15s ease}
.lang-menu button:hover,.lang-menu button:focus-visible{background:rgba(255,255,255,.09);
  outline:none}
.lang-menu button[aria-current="true"]{background:rgba(240,85,155,.18);color:#fff}
.lang-code{font-size:11.5px;font-weight:800;letter-spacing:.04em;color:var(--ink-dim)}
.lang-menu button[aria-current="true"] .lang-code{color:var(--gold)}

/* ── Giấy + băng keo ─────────────────────────────────────────────────── */
.paper{position:relative;color:var(--paper-ink);border-radius:4px;padding:30px 26px;
  background:linear-gradient(160deg,var(--paper),var(--paper-2));
  box-shadow:0 26px 60px -30px rgba(0,0,0,.85),0 3px 10px rgba(0,0,0,.35)}
.paper h3{color:var(--paper-ink)}
.paper p{color:var(--paper-ink-dim)}
.tape{position:absolute;width:104px;height:28px;left:50%;top:-14px;
  transform:translateX(-50%) rotate(-2.4deg);border-radius:2px;
  background:repeating-linear-gradient(115deg,var(--tape) 0 10px,
    rgba(246,198,103,.22) 10px 20px);
  box-shadow:0 2px 6px rgba(0,0,0,.25);pointer-events:none}
.tape.left{left:24px;transform:rotate(-9deg)}
.tape.right{left:auto;right:20px;transform:rotate(7deg)}
.tape.violet{background:repeating-linear-gradient(115deg,rgba(167,139,250,.5) 0 10px,
  rgba(167,139,250,.26) 10px 20px)}
.tape.rose{background:repeating-linear-gradient(115deg,rgba(240,85,155,.48) 0 10px,
  rgba(240,85,155,.24) 10px 20px)}
.scribble{display:block;color:var(--gold);font-size:clamp(20px,2.2vw,26px);
  transform:rotate(-2deg);margin-bottom:8px}

/* ── Header ──────────────────────────────────────────────────────────── */
.site-head{position:sticky;top:0;z-index:20;padding:12px 0;
  transition:background-color .3s ease,box-shadow .3s ease}
.site-head.stuck{background:rgba(21,11,29,.84);backdrop-filter:blur(14px);
  -webkit-backdrop-filter:blur(14px);box-shadow:0 1px 0 rgba(255,255,255,.08)}
.head-in{display:flex;align-items:center;gap:14px}
.brand{display:flex;align-items:center;gap:11px;text-decoration:none;color:inherit;flex:none}
.brand img{width:42px;height:42px;border-radius:13px;
  box-shadow:0 8px 20px -8px rgba(240,85,155,.9)}
.brand b{display:block;font-family:Nunito,sans-serif;font-weight:900;font-size:20px;
  line-height:1.05}
.brand span{display:block;font-size:12.5px;color:var(--ink-dim)}
.head-nav{display:none;gap:2px;margin-left:auto}
.head-nav a{padding:9px 11px;border-radius:999px;color:var(--ink-dim);font-size:15px;
  font-weight:600;text-decoration:none;transition:color .2s,background-color .2s}
.head-nav a:hover{color:var(--ink);background:rgba(255,255,255,.07)}
.head-tools{display:flex;align-items:center;gap:8px;margin-left:auto}
.head-nav+.head-tools{margin-left:0}
.head-cta{display:none}

/* ── Hero ────────────────────────────────────────────────────────────── */
.hero{position:relative;z-index:2;padding:clamp(20px,3vw,44px) 0 clamp(32px,4vw,56px)}
.hero-in{display:grid;gap:clamp(40px,6vw,64px);align-items:center}
.hero h1{margin:2px 0 20px}
.mark{position:relative;white-space:nowrap}
.mark::after{content:"";position:absolute;left:-4px;right:-4px;bottom:.08em;height:.32em;
  background:linear-gradient(90deg,rgba(246,198,103,.7),rgba(240,85,155,.55));
  transform:rotate(-1deg) scaleX(0);transform-origin:left;border-radius:3px;z-index:-1;
  animation:markIn .75s .45s cubic-bezier(.2,.8,.3,1) forwards}
@keyframes markIn{to{transform:rotate(-1deg) scaleX(1)}}
.hero .lead{margin-bottom:30px;font-size:clamp(17px,1.7vw,20px)}
.hero-cta{display:flex;flex-wrap:wrap;gap:12px;align-items:center}
.note-under{margin-top:18px;color:var(--ink-dim);font-size:15px;
  display:flex;align-items:center;gap:10px;flex-wrap:wrap}
.note-under .hand{color:var(--gold);font-size:19px}

/* Ảnh app trong khung máy, nghiêng nhẹ, dán băng keo */
.shot-wrap{position:relative;display:flex;justify-content:center}
.shot-wrap::before{content:"";position:absolute;inset:6% -8% -8% -8%;z-index:0;
  background:radial-gradient(58% 52% at 50% 50%,rgba(240,85,155,.32),transparent 72%);
  filter:blur(30px)}
.shot{position:relative;z-index:1;width:min(300px,78vw);border-radius:34px;padding:9px;
  background:linear-gradient(160deg,#3A2450,#1E1230);
  border:1px solid rgba(255,255,255,.16);
  box-shadow:0 40px 90px -36px rgba(0,0,0,.95);transform:rotate(-1.6deg)}
.shot img{border-radius:27px;width:100%}
.shot .tape{top:-15px}
.float{animation:float 9s ease-in-out infinite}
@keyframes float{0%,100%{transform:rotate(-1.6deg) translateY(0)}
  50%{transform:rotate(-.5deg) translateY(-14px)}}

/* ── Dải số ──────────────────────────────────────────────────────────── */
.strip{position:relative;z-index:2}
.strip-in{display:grid;grid-template-columns:repeat(2,1fr);gap:14px}
.stat{padding:20px 18px;border-radius:14px;text-align:center;
  background:rgba(255,255,255,.05);border:1px solid rgba(255,255,255,.1)}
.stat b{display:block;font-family:Nunito,sans-serif;font-weight:900;font-size:36px;
  line-height:1;background:linear-gradient(135deg,var(--gold),var(--rose));
  -webkit-background-clip:text;background-clip:text;color:transparent}
.stat span{font-size:13.5px;color:var(--ink-dim);font-weight:600}

/* ── Khối xen kẽ chữ / ảnh ───────────────────────────────────────────── */
.sec-head{max-width:64ch;margin-bottom:clamp(24px,3vw,40px)}
.sec-head h2{margin-bottom:14px}
.spread{display:grid;gap:clamp(26px,4vw,52px);align-items:center;margin-bottom:var(--space)}
.spread:last-child{margin-bottom:0}
.spread .shot{transform:rotate(1.4deg)}
.spread.flip .shot{transform:rotate(-1.8deg)}
/* Hai ảnh chồng lệch nhau (mục hích + nhịp tim) */
.spread .shot-pair{flex-direction:column;align-items:center}
.spread .shot-pair .shot{width:min(270px,70vw)}
.spread .shot-pair .shot:first-of-type{align-self:flex-start;margin-left:2%;transform:rotate(-2.4deg)}
.spread .shot-pair .shot:last-of-type{align-self:flex-end;margin:-28px 2% 0 0;transform:rotate(2deg)}
.spread-copy h2{margin-bottom:16px}
.spread-copy .lead{margin-bottom:24px}
.tick{list-style:none;display:grid;gap:14px}
.tick li{display:flex;gap:12px;align-items:flex-start}
.tick .icon{width:22px;height:22px;color:var(--gold);margin-top:3px}
.tick b{font-weight:700;display:block}
.tick span{color:var(--ink-dim);display:block;font-size:15.5px}

/* ── Thẻ giấy ────────────────────────────────────────────────────────── */
.cards{display:grid;gap:24px}
.cards .paper{transform:rotate(-.8deg);
  transition:transform .3s cubic-bezier(.2,.9,.3,1.2)}
.cards .paper:nth-child(even){transform:rotate(1deg)}
.cards .paper:hover{transform:rotate(0) translateY(-6px)}
.paper .feat-ic{width:44px;height:44px;border-radius:12px;display:grid;place-items:center;
  color:#fff;background:linear-gradient(135deg,var(--rose-deep),#7C3AED);margin-bottom:14px}
.paper h3{margin-bottom:8px}
.step-n{font-family:"Patrick Hand",cursive;font-size:30px;color:var(--rose-deep);
  line-height:1;margin-bottom:4px;display:block}

/* ── Polaroid rải ────────────────────────────────────────────────────── */
.polas{display:flex;flex-wrap:wrap;gap:20px;justify-content:center}
.pola{position:relative;background:var(--paper);padding:10px 10px 6px;border-radius:3px;
  box-shadow:0 22px 44px -24px rgba(0,0,0,.9);width:min(208px,43vw);
  transition:transform .3s cubic-bezier(.2,.9,.3,1.2)}
.pola:nth-child(1){transform:rotate(-3deg)}
.pola:nth-child(2){transform:rotate(2.2deg)}
.pola:nth-child(3){transform:rotate(-1.4deg)}
.pola:nth-child(4){transform:rotate(3deg)}
.pola:hover{transform:rotate(0) translateY(-8px) scale(1.02)}
.pola i{display:block;aspect-ratio:4/3;border-radius:2px}
.pola p{font-family:"Patrick Hand",cursive;color:var(--paper-ink);font-size:18px;
  text-align:center;margin-top:8px;line-height:1.25}
.pola .tape{width:72px;height:21px;top:-10px}
.p1{background:linear-gradient(140deg,#F0559B,#A78BFA 70%)}
.p2{background:linear-gradient(140deg,#F6C667,#F0559B)}
.p3{background:linear-gradient(140deg,#7DD3FC,#A78BFA)}
.p4{background:linear-gradient(140deg,#86EFAC,#F6C667)}

/* ── Riêng tư ────────────────────────────────────────────────────────── */
.priv{display:grid;gap:14px}
.priv li{display:flex;gap:14px;padding:20px 22px;border-radius:14px;list-style:none;
  background:rgba(255,255,255,.05);border:1px solid rgba(255,255,255,.1)}
.priv .icon{width:22px;height:22px;color:var(--gold);margin-top:3px}
.priv b{display:block;margin-bottom:4px}
.priv span{color:var(--ink-dim);font-size:15.5px}

/* ── Riêng tư + Hỏi đáp: 2 cột trên màn rộng ─────────────────────────── */
.duo{display:grid;gap:clamp(40px,5vw,56px)}
.duo-col{scroll-margin-top:90px}
.duo .sec-head{margin-bottom:22px}

/* ── FAQ ─────────────────────────────────────────────────────────────── */
.faq{display:grid;gap:12px}
.faq details{background:rgba(255,255,255,.05);border:1px solid rgba(255,255,255,.1);
  border-radius:14px;overflow:hidden}
.faq summary{display:flex;align-items:center;justify-content:space-between;gap:16px;
  padding:20px 22px;cursor:pointer;font-weight:700;list-style:none}
.faq summary::-webkit-details-marker{display:none}
.faq summary .icon{color:var(--gold);transition:transform .25s ease}
.faq details[open] summary .icon{transform:rotate(180deg)}
.faq p{padding:0 22px 20px;color:var(--ink-dim);font-size:15.5px}

/* ── CTA cuối ────────────────────────────────────────────────────────── */
.final{position:relative;text-align:center;padding:clamp(44px,6vw,72px) 26px;
  background:linear-gradient(160deg,var(--paper),var(--paper-2));color:var(--paper-ink);
  border-radius:6px;transform:rotate(-.5deg);
  box-shadow:0 34px 70px -34px rgba(0,0,0,.9)}
.final h2{color:var(--paper-ink);margin-bottom:14px}
.final p{color:var(--paper-ink-dim);max-width:52ch;margin:0 auto 26px}
.final .scribble{color:var(--rose-deep)}
.final .hero-cta{justify-content:center}
.final .fine{margin-top:18px;font-size:14.5px}

/* ── Footer ──────────────────────────────────────────────────────────── */
.site-foot{position:relative;z-index:2;padding:52px 0 40px;
  border-top:1px solid rgba(255,255,255,.08)}
.foot-in{display:flex;flex-wrap:wrap;gap:24px;justify-content:space-between;align-items:center}
.foot-brand{display:flex;align-items:center;gap:12px}
.foot-brand img{width:34px;height:34px;border-radius:10px}
.foot-brand b{font-family:Nunito,sans-serif;font-size:17px;display:block}
.foot-brand span{color:var(--ink-dim);font-size:14px}
.foot-nav{display:flex;flex-wrap:wrap;gap:8px 20px}
.foot-nav a{color:var(--ink-dim);font-size:14.5px;font-weight:600;text-decoration:none}
.foot-nav a:hover{color:var(--rose);text-decoration:underline}
.foot-note{margin-top:28px;text-align:center;color:var(--ink-dim);font-size:13.5px}
.foot-note .hand{color:var(--gold);font-size:17px}

/* ── Reveal ──────────────────────────────────────────────────────────── */
.reveal{opacity:0;transform:translateY(26px) rotate(-.4deg);
  transition:opacity .7s cubic-bezier(.2,.9,.3,1),transform .7s cubic-bezier(.2,.9,.3,1)}
.reveal.in{opacity:1;transform:none}

/* ── Responsive ──────────────────────────────────────────────────────── */
@media (min-width:620px){
  .strip-in{grid-template-columns:repeat(4,1fr)}
  .cards{grid-template-columns:repeat(2,1fr)}
  .priv{grid-template-columns:repeat(2,1fr)}
  .head-cta{display:inline-flex}
}
@media (min-width:960px){
  body{font-size:18px}
  .thread{display:block}
  .hero-in{grid-template-columns:1.06fr .94fr}
  .shot{width:min(300px,28vw)}
  .hero .shot{width:min(380px,34vw)}
  .spread .shot-pair .shot{width:min(280px,25vw)}
  .spread .shot-pair .shot:last-of-type{margin-top:-64px}
  .spread{grid-template-columns:1fr 1fr}
  .spread.flip .spread-copy{order:2}
  .cards{grid-template-columns:repeat(3,1fr)}
  .duo{grid-template-columns:1fr 1fr;align-items:start}
  .duo .priv{grid-template-columns:1fr}
}
@media (min-width:1100px){
  .head-nav{display:flex}
}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{animation:none!important;transition-duration:.01ms!important}
  .reveal{opacity:1;transform:none}
  .mark::after{transform:rotate(-1deg) scaleX(1)}
  #hearts{display:none}
}

/* Tiếng Nhật/Hàn: ngắt dòng theo cụm từ, không cắt giữa từ (Chrome/Edge 119+,
   trình duyệt khác bỏ qua và ngắt như cũ). */
:lang(ja) :is(h1,h2,h3,.lead,.scribble),:lang(ko) :is(h1,h2,h3){word-break:auto-phrase}
:lang(ko) :is(h1,h2,h3,.lead,p){word-break:keep-all}