/* Diphony — hệ SÁNG có sắc độ.
   Nguyên tắc: nền không bao giờ là trắng tinh (trắng tinh + viền xám = template);
   tương phản tạo bằng MÀU và sắc độ, không bằng đen–trắng. Tỉ lệ 60/30/10:
   60% nền trung tính ấm, 30% indigo (đường "Me"), 10% cam (đường "Them"). */
:root{
  --t1:clamp(38px,5.6vw,66px); --t2:clamp(25px,2.9vw,36px); --t3:20px;
  --t4:17px; --t5:15px; --t6:13px; --label:11.5px;
  --sans:"Inter",-apple-system,BlinkMacSystemFont,"SF Pro Text","Segoe UI",Roboto,Arial,sans-serif;

  --paper:#FBFAF7;        /* kem ấm — nền chủ đạo */
  --surface:#FFFFFF;      /* thẻ nổi trên kem */
  --lav:#F4F0FA;          /* lavender rất nhạt */
  --peach:#FFF5EA;        /* cam rất nhạt */
  --ink:#1C1A38;          /* mực, không phải đen */
  --dim:#57547A;
  --faint:#666387;
  --line:#EBE6F1;
  --line-warm:#F0E7DA;
  --brand:#4F49D8;        /* Me */
  --brand-ink:#3B35A8;
  --them:#D97A16;         /* Them */
  --ok:#127A45;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth;background:var(--paper)}
body{margin:0;background:var(--paper);color:var(--ink);font-family:var(--sans);
  font-size:var(--t5);line-height:1.6;overflow-x:hidden;
  -webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility}
/* height:auto là BẮT BUỘC khi thẻ có width/height: thiếu nó, chiều cao khai
   trong HTML bị giữ nguyên trong khi chiều rộng co lại → ảnh méo dọc, còn
   video thì tự độn viền trắng trên dưới cho đủ chiều cao. */
img,video,svg{max-width:100%;height:auto}
a{color:var(--brand)}
.wrap{max-width:1020px;margin:0 auto;padding:0 26px}
:focus-visible{outline:2px solid var(--brand);outline-offset:4px;border-radius:8px}
@media (prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important}}

/* ── thanh trên ────────────────────────────────────────── */
.nav{position:sticky;top:0;z-index:30;background:rgba(251,250,247,.82);
  backdrop-filter:saturate(180%) blur(14px);border-bottom:1px solid var(--line)}
.nav .wrap{display:flex;align-items:center;gap:12px;height:62px}
.nav img{width:28px;height:28px}
.nav b{font-size:var(--t4);letter-spacing:-.3px;flex:1;font-weight:650}
.nav a{font-size:var(--t5);color:var(--dim);text-decoration:none;margin-left:22px;font-weight:500}
.nav a:hover{color:var(--brand)}
.nav .cta{background:var(--brand);color:#fff;padding:8px 16px;border-radius:10px;font-weight:650}
.nav .cta:hover{background:var(--brand-ink);color:#fff}

/* ── hero: nền MÀU, không trắng, không tối ─────────────── */
.hero{padding:88px 0 0;text-align:center;
  background:linear-gradient(178deg,#F1ECFB 0%,#F6F1FA 46%,var(--paper) 100%)}
.hero .eyebrow{display:inline-flex;align-items:center;gap:8px;font-size:var(--label);
  font-weight:700;letter-spacing:1.2px;text-transform:uppercase;color:var(--brand-ink);
  border:1px solid rgba(79,73,216,.22);background:rgba(79,73,216,.07);
  padding:7px 15px;border-radius:999px;margin-bottom:24px}
.hero .eyebrow i{width:6px;height:6px;border-radius:50%;background:var(--them);font-style:normal}
h1{font-size:var(--t1);line-height:1.04;letter-spacing:-.042em;font-weight:800;margin:0 0 20px}
h1 .me{color:var(--brand)}
h1 .them{color:var(--them)}
.hero p.sub{font-size:clamp(16px,1.6vw,19px);color:var(--dim);max-width:46ch;
  margin:0 auto 30px;line-height:1.55}
.actions{display:flex;gap:22px;justify-content:center;align-items:center;flex-wrap:wrap}
.btn{display:inline-block;padding:15px 30px;border-radius:13px;font-size:var(--t4);
  font-weight:650;text-decoration:none;background:var(--brand);color:#fff;
  box-shadow:0 12px 30px rgba(79,73,216,.30);transition:transform .14s ease,box-shadow .14s ease}
.btn:hover{transform:translateY(-2px);box-shadow:0 18px 42px rgba(79,73,216,.40);
  background:var(--brand-ink);color:#fff}
.linkish{color:var(--dim);text-decoration:none;font-size:var(--t5);font-weight:600;
  display:inline-flex;align-items:center;gap:7px}
.linkish:hover{color:var(--brand)}
.linkish::after{content:"→";transition:transform .15s ease}
.linkish:hover::after{transform:translateX(4px)}
.hero .plat{font-size:var(--t6);color:var(--faint);margin:22px 0 0;max-width:none}

/* ảnh app: nền sáng nên dùng bóng MỀM + viền trắng dày, không dùng quầng phát sáng */
.stage{margin:50px auto -60px;max-width:1080px;padding:0 26px;position:relative}
.stage .frame{border-radius:18px;overflow:hidden;background:#fff;padding:8px;
  box-shadow:0 40px 80px rgba(28,26,56,.16), 0 4px 12px rgba(28,26,56,.06)}
.stage .frame > *{border-radius:11px;display:block;width:100%}

/* ── dải nội dung: xen kẽ kem / lavender / cam nhạt ────── */
section{padding:96px 0}
section.pad-top{padding-top:132px}
section.lav{background:var(--lav)}
section.peach{background:var(--peach)}
section.brand{background:linear-gradient(160deg,var(--brand) 0%,#5B4FE0 55%,var(--brand-ink) 100%);
  color:#fff}
section.brand h2{color:#fff}
section.brand .lead{color:rgba(255,255,255,.90)}
section.brand .kicker{color:#E6E4FF}
section.brand a{color:#fff;text-decoration:underline;text-underline-offset:3px}

.kicker{font-size:var(--label);font-weight:800;letter-spacing:1.5px;text-transform:uppercase;
  color:var(--brand);margin:0 0 14px}
section h2,.closer h2{font-size:var(--t2);line-height:1.15;letter-spacing:-.03em;font-weight:750;margin:0 0 16px;max-width:20ch}
.lead{font-size:var(--t4);color:var(--dim);line-height:1.68;margin:0;max-width:62ch}

/* ── số liệu ───────────────────────────────────────────── */
.stats{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin:38px 0 0}
.stat{background:var(--surface);border:1px solid var(--line);border-radius:16px;padding:24px 24px;
  box-shadow:0 6px 18px rgba(28,26,56,.05)}
.stat .n{font-size:clamp(32px,3.8vw,46px);font-weight:800;letter-spacing:-.04em;line-height:1;
  color:var(--brand)}
.stat .n.win{color:var(--ok)}
.stat .n.them{color:var(--them)}
.stat .t{font-size:var(--t6);color:var(--dim);margin-top:10px;line-height:1.5}
section.brand .stat{background:rgba(255,255,255,.11);border-color:rgba(255,255,255,.22);box-shadow:none}
section.brand .stat .n,section.brand .stat .n.win,section.brand .stat .n.them{color:#fff}
section.brand .stat .t{color:rgba(255,255,255,.90)}

/* ── hai cột đối chiếu ─────────────────────────────────── */
.versus{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin-top:34px}
.card{border-radius:18px;padding:24px 26px;background:var(--surface);border:1px solid var(--line)}
.card h3{font-size:var(--label);font-weight:800;letter-spacing:1px;text-transform:uppercase;margin:0 0 14px}
.card.bad{background:var(--peach);border-color:var(--line-warm)}
.card.bad h3{color:var(--them-ink)}
.card.good{background:linear-gradient(180deg,#F0EEFE,#fff);border-color:rgba(79,73,216,.26);
  box-shadow:0 10px 30px rgba(79,73,216,.10)}
.card.good h3{color:var(--brand)}
.card ul{margin:0;padding-left:0;list-style:none;font-size:var(--t5);color:var(--dim)}
.card li{margin-bottom:10px;padding-left:22px;position:relative;line-height:1.55}
.card li::before{content:"";position:absolute;left:0;top:9px;width:9px;height:2px;border-radius:2px;
  background:var(--them);opacity:.8}
.card.good li::before{background:var(--brand);opacity:1;width:11px}

/* ── tính năng ─────────────────────────────────────────── */
.feature{display:grid;grid-template-columns:0.92fr 1.08fr;gap:52px;align-items:center;margin:52px 0}
.feature.flip .txt{order:2}
.feature h3{font-size:var(--t3);letter-spacing:-.02em;margin:0 0 12px;font-weight:700}
.feature p{font-size:var(--t5);color:var(--dim);margin:0;line-height:1.7}
.kbd{display:inline-block;margin-top:16px;font-size:var(--t6);color:var(--dim);
  border:1px solid var(--line);border-radius:8px;padding:6px 11px;background:var(--surface)}
.feature figure{margin:0}
.feature img{border-radius:14px;display:block;background:#fff;padding:6px;
  box-shadow:0 20px 46px rgba(28,26,56,.13)}

/* ── giá ───────────────────────────────────────────────── */
.plans{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin-top:34px;align-items:start}
.plan{border:1px solid var(--line);border-radius:20px;padding:28px 26px;background:var(--surface);
  position:relative;box-shadow:0 6px 18px rgba(28,26,56,.05)}
.plan.best{border-color:rgba(79,73,216,.5);box-shadow:0 22px 52px rgba(79,73,216,.22);
  background:linear-gradient(180deg,#EFECFD,#fff);transform:translateY(-10px);
  padding-top:34px;padding-bottom:34px}
@media (max-width:820px){.plan.best{transform:none}}
.plan .tag{position:absolute;top:-12px;left:26px;background:var(--brand);color:#fff;
  font-size:var(--label);font-weight:800;letter-spacing:.5px;padding:6px 13px;border-radius:999px;
  box-shadow:0 6px 16px rgba(79,73,216,.34)}
.plan .k{font-size:var(--label);font-weight:800;letter-spacing:1px;text-transform:uppercase;color:var(--faint)}
.plan.best .k{color:var(--brand)}
.plan .p{font-size:clamp(27px,3vw,36px);font-weight:800;letter-spacing:-.04em;margin:8px 0 6px;line-height:1}
.plan .p span{font-size:var(--t5);font-weight:500;color:var(--faint);letter-spacing:0}
.plan .alt{font-size:var(--t6);color:var(--faint);margin:0 0 18px}
.plan ul{margin:0;padding-left:0;list-style:none;font-size:var(--t5);color:var(--dim)}
.plan li{margin-bottom:9px;padding-left:20px;position:relative}
.plan li::before{content:"";position:absolute;left:0;top:8px;width:9px;height:2px;
  border-radius:2px;background:var(--brand);opacity:.8}

/* ── bảng thông số ────────────────────────────────────── */
.specs{display:grid;grid-template-columns:1fr 1fr;gap:0 44px;margin:34px 0 0}
.spec{display:flex;gap:18px;padding:15px 2px;border-bottom:1px solid var(--line-warm);
  align-items:baseline}
.spec dt{flex:none;width:118px;font-size:var(--t6);font-weight:700;letter-spacing:.4px;
  color:var(--them-ink)}
.spec dd{margin:0;font-size:var(--t5);color:var(--dim);line-height:1.5}
@media (max-width:820px){.specs{grid-template-columns:1fr;gap:0}
  .spec{flex-direction:column;gap:4px}.spec dt{width:auto}}

/* ── hỏi đáp ───────────────────────────────────────────── */
details{border-bottom:1px solid var(--line);padding:18px 0}
details summary{font-size:var(--t4);font-weight:600;cursor:pointer;list-style:none;
  display:flex;justify-content:space-between;gap:18px}
details summary::-webkit-details-marker{display:none}
details summary::after{content:"+";color:var(--brand);font-weight:400;font-size:20px;line-height:1;flex:none}
details[open] summary::after{content:"–"}
details p{font-size:var(--t5);color:var(--dim);margin:12px 0 0;line-height:1.7;max-width:70ch}

figcaption{font-size:var(--t6);color:var(--faint);margin-top:14px}
section.brand figcaption{color:rgba(255,255,255,.86)}
footer{border-top:1px solid var(--line);padding:30px 0 46px;color:var(--faint);font-size:var(--t6);
  display:flex;gap:22px;align-items:center;flex-wrap:wrap}
footer a{color:var(--faint);text-decoration:none}
footer a:hover{color:var(--brand)}
footer .sp{flex:1}

@media (max-width:820px){
  :root{--t3:19px;--t4:16px}
  section{padding:60px 0}
  section.pad-top{padding-top:96px}
  .hero{padding-top:56px}
  .stage{margin-bottom:-40px}
  .stats,.versus,.plans{grid-template-columns:1fr}
  .feature{grid-template-columns:1fr;gap:22px}
  .feature.flip .txt{order:0}
  .nav a:not(.cta){display:none}
  section h2{max-width:none}
}

/* ── trang văn bản (Privacy · Terms · Support) ─────────── */
.doc{max-width:760px;padding-top:34px;padding-bottom:64px}
.doc > header{display:flex;align-items:center;gap:10px;margin-bottom:34px}
.doc > header img{width:26px;height:26px}
.doc > header b{font-size:var(--t4);letter-spacing:-.3px}
.doc h1{font-size:clamp(30px,3.6vw,42px);letter-spacing:-.035em;margin:0 0 8px}
.doc h2{font-size:var(--t3);letter-spacing:-.02em;font-weight:700;margin:38px 0 12px}
.doc p,.doc li{color:var(--dim);line-height:1.72}
.doc b{color:var(--ink)}
.doc a{color:var(--brand);text-underline-offset:3px}
.doc .upd{font-size:var(--t6);color:var(--faint);margin:0 0 26px}
.doc .box{background:var(--lav);border:1px solid #DCD7F8;border-left:3px solid var(--brand);
  border-radius:14px;padding:18px 20px;margin:26px 0;color:var(--dim)}
.doc ul{padding-left:20px}
.doc li{margin-bottom:8px}
.doc footer{margin-top:52px}

/* ── lời mời cuối trang ────────────────────────────────── */
.closer{background:linear-gradient(170deg,#F4F0FA 0%,#FBF3EA 100%);border-top:1px solid var(--line);
  text-align:center;padding:88px 0 92px}
.closer h2{margin:0 auto 14px;max-width:none;font-size:var(--t2)}
.closer p{color:var(--dim);font-size:var(--t4);margin:0 auto 28px;max-width:52ch}
.closer .fine{font-size:var(--t6);color:var(--faint);margin:20px auto 0}