:root{
  --bg:#000;
  --panel:#0c0c0e;
  --ink:#f5f5f7;
  --muted:#86868b;
  --line:rgba(255,255,255,.10);
  --maxw:1080px;
  --sans:-apple-system,BlinkMacSystemFont,"SF Pro Display","Segoe UI",system-ui,Helvetica,Arial,sans-serif;
  --jp:"Hiragino Sans","Hiragino Kaku Gothic ProN",-apple-system,"Yu Gothic","Noto Sans JP",Meiryo,sans-serif;
}

*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;overflow-x:clip}
body{
  font-family:var(--sans);
  background:var(--bg);
  color:var(--ink);
  line-height:1.5;
  overflow-x:clip;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}

h1,h2,h3{font-weight:600;letter-spacing:-.025em;line-height:1.06}
h1{font-size:clamp(2.6rem,6.4vw,5rem)}
h2{font-size:clamp(1.9rem,4.2vw,3.2rem)}
.kicker{color:var(--muted);font-size:clamp(.92rem,1.4vw,1.05rem);font-weight:500;letter-spacing:.01em;margin-bottom:20px}
.sub{color:var(--muted);font-size:clamp(1.06rem,1.7vw,1.32rem);font-weight:400;max-width:38ch;margin:22px auto 0;line-height:1.5}

/* ---------- nav ---------- */
.nav{
  position:sticky;top:0;z-index:50;
  display:flex;align-items:center;justify-content:space-between;
  padding:16px clamp(20px,5vw,42px);
  border-bottom:1px solid transparent;transition:background .3s,border-color .3s,backdrop-filter .3s;
}
.nav.scrolled{background:rgba(0,0,0,.6);backdrop-filter:saturate(160%) blur(18px);border-bottom-color:var(--line)}
.brand{display:flex;align-items:center;gap:10px;text-decoration:none;color:var(--ink);font-weight:600;font-size:1.18rem;letter-spacing:-.01em}
.brand img{border-radius:8px}
.nav-right{display:flex;align-items:center;gap:12px}
.nav-link{color:var(--muted);text-decoration:none;font-size:.95rem;transition:color .2s}
.nav-link:hover{color:var(--ink)}
.nav-cta{color:var(--ink);text-decoration:none;font-size:.95rem;font-weight:500;padding:8px 16px;border:1px solid var(--line);border-radius:980px;transition:background .2s,border-color .2s}
.nav-cta:hover{background:rgba(255,255,255,.08);border-color:rgba(255,255,255,.25)}

/* ---------- sections ---------- */
section{padding:clamp(50px,7.5vw,96px) clamp(20px,5vw,42px)}
.hero,.review,.band,.final{max-width:var(--maxw);margin:0 auto;text-align:center}

/* ---------- hero ---------- */
.hero{padding-top:clamp(50px,8vw,96px)}
.hero .sub{max-width:none;margin-bottom:32px}
.cta{display:flex;flex-direction:column;align-items:center;gap:14px}
.appbtn{display:inline-flex;align-items:center;gap:9px;background:#fff;color:#000;text-decoration:none;font-weight:500;font-size:1.04rem;padding:13px 26px;border-radius:980px;transition:transform .2s,background .2s}
.appbtn:hover{background:#e6e6e9;transform:translateY(-1px)}
.appbtn svg{display:block}
.appbtn-alt{background:none;color:var(--ink);border:1px solid var(--line)}
.appbtn-alt:hover{background:rgba(255,255,255,.08);border-color:rgba(255,255,255,.25)}

.hero-stage{position:relative;margin-top:clamp(34px,5vw,60px);display:flex;justify-content:center}
.spotlight{position:absolute;top:-8%;left:50%;transform:translateX(-50%);width:min(760px,120%);aspect-ratio:1;border-radius:50%;z-index:0;background:radial-gradient(circle,rgba(255,255,255,.12),rgba(255,255,255,.03) 38%,transparent 62%);filter:blur(8px);pointer-events:none}

/* ---------- device frame ---------- */
.device{
  position:relative;z-index:1;width:min(300px,72vw);
  border-radius:42px;padding:9px;background:#1a1a1c;
  box-shadow:0 1px 0 rgba(255,255,255,.14) inset,0 50px 120px -40px rgba(0,0,0,.9),0 0 0 1px rgba(0,0,0,.6);
}
.device-lg{width:min(330px,80vw)}
.device-screen{
  display:block;width:100%;aspect-ratio:9/18.5;border-radius:34px;background:#000;
  overflow:hidden;position:relative;
}

/* simulated feed inside the device */
.feed-sim{position:absolute;inset:0;display:flex;flex-direction:column;justify-content:flex-end;padding:0 14px 26px;text-align:center}
.feed-sim .fs-line{font-family:var(--jp);font-size:1.35rem;line-height:1.6;text-shadow:0 1px 8px rgba(0,0,0,.8);opacity:0;transform:translateY(6px);animation:fsin 1.2s ease forwards}
.feed-sim .fs-romaji{color:rgba(255,255,255,.75);font-size:.85rem;margin-top:6px;opacity:0;animation:fsin 1.2s .2s ease forwards}
.feed-sim .fs-en{color:rgba(255,255,255,.75);font-size:.85rem;margin-top:2px;opacity:0;animation:fsin 1.2s .4s ease forwards}
.feed-sim ruby rt{font-size:.52em;color:rgba(255,255,255,.85);font-weight:400}
@keyframes fsin{to{opacity:1;transform:none}}
.feed-sim .fs-top{position:absolute;top:18px;left:16px;right:16px;text-align:left;font-size:.8rem;color:rgba(255,255,255,.6);display:flex;justify-content:space-between}
.feed-sim .fs-progress{position:absolute;top:0;left:0;right:0;height:3px;background:rgba(255,255,255,.12)}
.feed-sim .fs-progress span{display:block;height:100%;width:0;background:linear-gradient(90deg,#ff5d73,#ffb454);animation:fsbar 4s linear forwards}
@keyframes fsbar{to{width:100%}}

.feed-sim .fs-sky {
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, #0b1030 0%, #2a1a4e 42%, #5a2a58 68%, #b4505a 100%);
  animation: fssky 16s ease-in-out infinite alternate;
}

@keyframes fssky {
  0% { filter: hue-rotate(0deg) brightness(1); }
  50% { filter: hue-rotate(24deg) brightness(1.08); }
  100% { filter: hue-rotate(-12deg) brightness(0.96); }
}

.feed-sim .fs-stars {
  position: absolute;
  inset: 0 0 34% 0;
  background-image:
    radial-gradient(1.6px 1.6px at 18% 22%, rgba(255,255,255,.9), transparent 60%),
    radial-gradient(1.2px 1.2px at 34% 12%, rgba(255,255,255,.7), transparent 60%),
    radial-gradient(1.8px 1.8px at 52% 30%, rgba(255,255,255,.85), transparent 60%),
    radial-gradient(1.2px 1.2px at 68% 16%, rgba(255,255,255,.75), transparent 60%),
    radial-gradient(1.5px 1.5px at 82% 26%, rgba(255,255,255,.9), transparent 60%),
    radial-gradient(1px 1px at 10% 46%, rgba(255,255,255,.6), transparent 60%),
    radial-gradient(1.3px 1.3px at 44% 48%, rgba(255,255,255,.7), transparent 60%),
    radial-gradient(1.1px 1.1px at 60% 40%, rgba(255,255,255,.65), transparent 60%),
    radial-gradient(1.4px 1.4px at 90% 44%, rgba(255,255,255,.8), transparent 60%),
    radial-gradient(1.2px 1.2px at 28% 60%, rgba(255,255,255,.55), transparent 60%);
  animation: fsstars 3.4s ease-in-out infinite alternate;
}

@keyframes fsstars {
  from { opacity: 0.55; }
  to { opacity: 1; }
}

.feed-sim .fs-sun {
  position: absolute;
  left: 50%;
  top: 16%;
  width: 46%;
  aspect-ratio: 1;
  transform: translateX(-50%);
  border-radius: 50%;
  background: radial-gradient(circle at 42% 38%, #ffe9c9 0%, #ffb45c 34%, #ff6a5e 68%, rgba(255,106,94,0) 100%);
  animation: fssun 5.2s ease-in-out infinite alternate;
}

@keyframes fssun {
  from { transform: translateX(-50%) scale(0.92); filter: brightness(0.96); }
  to { transform: translateX(-50%) scale(1.06); filter: brightness(1.1); }
}

.feed-sim .fs-hills {
  position: absolute;
  left: -12%;
  right: -12%;
  bottom: 0;
  height: 30%;
  background: linear-gradient(180deg, rgba(16,12,26,0) 0%, #120c1e 30%, #0a0712 100%);
  clip-path: polygon(0 62%, 9% 46%, 18% 58%, 29% 34%, 41% 55%, 53% 40%, 64% 56%, 76% 38%, 88% 54%, 100% 44%, 100% 100%, 0 100%);
  animation: fshills 14s ease-in-out infinite alternate;
}

@keyframes fshills {
  from { transform: translateX(-2%); }
  to { transform: translateX(2%); }
}

.feed-sim.fs-scene-1 .fs-sky {
  background: linear-gradient(180deg, #4a1c1a 0%, #8a3a22 40%, #d97a3a 68%, #f2b05a 100%);
}

.feed-sim.fs-scene-1 .fs-sun {
  top: 46%;
  width: 30%;
  background: radial-gradient(circle at 42% 38%, #fff3d6 0%, #ffd28a 34%, #ff9a5c 68%, rgba(255,154,92,0) 100%);
}

.feed-sim.fs-scene-1 .fs-stars {
  display: none;
}

.feed-sim.fs-scene-2 .fs-sky {
  background: linear-gradient(180deg, #1a2c46 0%, #4a5f7a 38%, #d9a8b8 66%, #f7d9c4 100%);
}

.feed-sim.fs-scene-2 .fs-sun {
  top: 40%;
  width: 38%;
  background: radial-gradient(circle at 42% 38%, #fff6e8 0%, #ffd9c0 40%, #f7a8c0 72%, rgba(247,168,192,0) 100%);
}

.feed-sim.fs-scene-2 .fs-hills {
  background: linear-gradient(180deg, rgba(90,60,80,0) 0%, #5a3c50 30%, #2e1c2c 100%);
}

.feed-sim .fs-petals {
  position: absolute;
  inset: 0 0 30% 0;
  pointer-events: none;
  opacity: 0;
  background-image:
    radial-gradient(5px 5px at 15% 12%, rgba(255,190,205,.9), transparent 60%),
    radial-gradient(4px 4px at 38% 28%, rgba(255,170,195,.8), transparent 60%),
    radial-gradient(5px 5px at 62% 16%, rgba(255,200,210,.85), transparent 60%),
    radial-gradient(4px 4px at 82% 34%, rgba(255,180,200,.8), transparent 60%),
    radial-gradient(5px 5px at 26% 48%, rgba(255,190,205,.7), transparent 60%),
    radial-gradient(4px 4px at 70% 52%, rgba(255,175,195,.7), transparent 60%);
  animation: fspetals 6s linear infinite;
}

@keyframes fspetals {
  from { transform: translateY(-8%); opacity: 0.55; }
  50% { opacity: 1; }
  to { transform: translateY(14%); opacity: 0.55; }
}

.feed-sim.fs-scene-2 .fs-petals {
  opacity: 1;
}

/* ---------- library ---------- */
.library{max-width:var(--maxw);margin:0 auto;text-align:center}
.lib-head h2{max-width:18ch;margin:0 auto}
.posters{
  display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:14px;
  margin-top:clamp(30px,5vw,48px);max-width:760px;margin-left:auto;margin-right:auto;
}
.poster{
  aspect-ratio:2/3;border-radius:12px;overflow:hidden;position:relative;
  background:linear-gradient(160deg,#15151a,#0a0a0d);
  border:1px solid var(--line);
  display:flex;align-items:flex-end;padding:12px;
}
.poster span{font-size:.78rem;font-weight:600;color:var(--muted);text-align:left;line-height:1.3}
.poster::after{content:"";position:absolute;inset:0;background:radial-gradient(120% 60% at 50% 0%,rgba(255,255,255,.06),transparent 60%)}
.poster-real{padding:0;align-items:stretch}
.poster-real img{position:absolute;inset:0;width:100%;height:100%;object-fit:cover}
.poster-tag{position:relative;z-index:1;align-self:flex-start;margin-top:auto;background:rgba(0,0,0,.62);backdrop-filter:blur(4px);color:#fff;font-size:.7rem;font-weight:600;padding:4px 9px;border-radius:99px;margin:auto 8px 8px}

/* ---------- review ---------- */
.review h2{max-width:16ch;margin:0 auto}
.review .sub{margin-left:auto;margin-right:auto;margin-bottom:8px}
.review-card-sim{
  font-family:var(--jp);
  background:var(--panel);border:1px solid var(--line);border-radius:18px;
  padding:26px 20px;display:flex;flex-direction:column;gap:10px;align-items:center;
}
.review-card-sim .rc-word{font-size:2.1rem}
.review-card-sim .rc-sentence{color:var(--muted);font-size:1rem}
.review-card-sim .rc-grades{display:flex;gap:8px;margin-top:10px}
.review-card-sim .rc-grade{font-size:.78rem;font-weight:600;padding:7px 14px;border-radius:99px;border:1px solid var(--line);color:var(--muted)}

/* ---------- features ---------- */
.features{max-width:var(--maxw);margin:0 auto;display:grid;grid-template-columns:repeat(3,1fr);gap:clamp(28px,5vw,64px);border-top:1px solid var(--line);padding-top:clamp(44px,6vw,72px)}
.feat h3{font-size:1.35rem;margin-bottom:12px}
.feat p{color:var(--muted);font-size:1.02rem;line-height:1.5}

/* ---------- band ---------- */
.band{border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.band p{color:var(--muted);font-size:clamp(1.05rem,1.6vw,1.25rem);max-width:46ch;margin:0 auto}

/* ---------- final ---------- */
.final h2{font-size:clamp(2.4rem,5.5vw,4rem);margin-bottom:34px}
.final .cta{margin-bottom:16px}
.fineprint{color:var(--muted);font-size:.95rem}

/* ---------- footer ---------- */
.footer{
  max-width:var(--maxw);margin:0 auto;
  display:flex;align-items:center;justify-content:space-between;gap:16px;
  padding:26px clamp(20px,5vw,42px);flex-wrap:wrap;
}
.footer nav{display:flex;gap:20px;flex-wrap:wrap}
.footer a{color:var(--muted);text-decoration:none;font-size:.92rem;transition:color .2s}
.footer a:hover{color:var(--ink)}
.footer .muted{font-size:.88rem}

/* ---------- reveal ---------- */
.reveal{opacity:0;transform:translateY(14px);transition:opacity .7s ease,transform .7s ease}
.reveal.is-visible{opacity:1;transform:none}
.d1{transition-delay:.12s}
.d2{transition-delay:.24s}

/* ---------- learn pages ---------- */
.word{max-width:var(--maxw);margin:0 auto;padding:clamp(36px,6vw,72px) clamp(20px,5vw,42px)}
.crumb{margin-bottom:26px}
.crumb a{color:var(--muted);text-decoration:none;font-size:.95rem}
.crumb a:hover{color:var(--ink)}
.word-hero{margin-bottom:34px}
.word-hero h1{font-size:clamp(2.4rem,5.5vw,4rem)}
.word-romaji{color:var(--muted);font-size:1.3rem;margin-top:6px}
.word-meaning{font-size:1.2rem;margin-top:4px}
.jlpt{display:inline-block;font-size:.78rem;font-weight:700;padding:3px 10px;border-radius:99px;margin-bottom:16px}
.jlpt.n5{background:rgba(52,211,153,.14);color:#34d399}
.jlpt.n4{background:rgba(96,165,250,.14);color:#60a5fa}
.jlpt.n3{background:rgba(251,191,36,.14);color:#fbbf24}
.jlpt.n2{background:rgba(255,93,115,.14);color:#ff5d73}
.jlpt.n1{background:rgba(192,132,252,.14);color:#c084fc}
.word-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(180px,1fr));gap:10px}
.word-card{display:flex;flex-direction:column;gap:2px;background:var(--panel);border:1px solid var(--line);border-radius:14px;padding:14px;text-decoration:none;color:var(--ink);transition:border-color .2s,transform .2s}
.word-card:hover{border-color:rgba(255,255,255,.28);transform:translateY(-1px)}
.wc-jlpt{font-size:.68rem;font-weight:700;color:var(--muted)}
.wc-kanji{font-family:var(--jp);font-size:1.35rem}
.wc-mean{color:var(--muted);font-size:.82rem}
.word-cta{text-align:center;margin-top:48px;padding-top:48px;border-top:1px solid var(--line)}
.word-cta p{color:var(--muted);margin:12px 0 22px}

/* ---------- legal ---------- */
.legal{max-width:760px;margin:0 auto;padding:clamp(36px,6vw,72px) clamp(20px,5vw,42px)}
.legal h1{font-size:clamp(2rem,4.5vw,3rem);margin-bottom:8px}
.legal .updated{color:var(--muted);font-size:.9rem;margin-bottom:34px}
.legal h2{font-size:1.3rem;margin:28px 0 10px}
.legal p,.legal li{color:#c8c8cc;font-size:.98rem;margin-bottom:10px}
.legal ul{margin-left:20px}
.legal a{color:var(--ink)}

@media (max-width:760px){
  .features{grid-template-columns:1fr}
}