:root{
  color-scheme:dark;--bg:#07111f;--bg2:#0b1930;--panel:rgba(16,31,54,.78);--panel2:rgba(23,42,71,.78);
  --line:rgba(255,255,255,.10);--line2:rgba(255,255,255,.17);--text:#f7f9fc;--muted:#aab8cb;--soft:#7f91aa;
  --gold:#ffd166;--cyan:#7ee7f2;--mint:#6ee7b7;--violet:#a78bfa;--danger:#fb7185;
  --ui:Aptos,"Segoe UI Variable Text","Segoe UI",system-ui,-apple-system,BlinkMacSystemFont,Arial,sans-serif;
  --jp:"Yu Gothic",YuGothic,"Hiragino Sans",Meiryo,"Noto Sans JP",sans-serif;
  --shadow:0 30px 80px rgba(0,0,0,.28);--r-xl:30px;--r-lg:22px;--r-md:16px;
}
*{box-sizing:border-box}html{background:var(--bg);scroll-behavior:smooth}html,body{margin:0;min-height:100%}
body{font-family:var(--ui);color:var(--text);background:
  radial-gradient(900px 540px at 8% -8%,rgba(72,127,210,.28),transparent 65%),
  radial-gradient(760px 520px at 100% 4%,rgba(126,87,194,.20),transparent 64%),
  linear-gradient(180deg,var(--bg2) 0,var(--bg) 58%,#06101d 100%);-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility}
body::before{content:"";position:fixed;inset:0;pointer-events:none;opacity:.35;background-image:linear-gradient(rgba(255,255,255,.018) 1px,transparent 1px),linear-gradient(90deg,rgba(255,255,255,.018) 1px,transparent 1px);background-size:42px 42px;mask-image:linear-gradient(to bottom,#000,transparent 70%)}
a{color:inherit}.jp,[lang="ja"]{font-family:var(--jp)}
.shell{width:min(1180px,100%);margin:auto;padding:max(18px,env(safe-area-inset-top)) max(18px,env(safe-area-inset-right)) max(38px,env(safe-area-inset-bottom)) max(18px,env(safe-area-inset-left))}
.topbar{display:flex;align-items:center;justify-content:space-between;gap:16px;min-height:58px;margin-bottom:34px}
.brand{display:flex;align-items:center;gap:12px;text-decoration:none}.brandmark{width:42px;height:42px;border-radius:14px;display:grid;place-items:center;background:linear-gradient(145deg,#fff7d1,#ffd166);color:#14233d;font-weight:950;box-shadow:0 10px 24px rgba(255,209,102,.16)}
.brandcopy{line-height:1.1}.brandcopy strong{display:block;font-size:15px;letter-spacing:.02em}.brandcopy span{display:block;margin-top:4px;color:var(--muted);font-size:12px}
.nav{display:flex;gap:8px;flex-wrap:wrap}.nav a{display:inline-flex;align-items:center;min-height:40px;padding:0 13px;border:1px solid var(--line);border-radius:12px;text-decoration:none;color:#dbe5f4;background:rgba(255,255,255,.035);font-weight:750;font-size:13px}
.nav a:hover{background:rgba(255,255,255,.07);border-color:var(--line2)}
.hero{display:grid;grid-template-columns:minmax(0,1.25fr) minmax(280px,.75fr);gap:22px;align-items:stretch;margin-bottom:28px}
.hero-main,.hero-side,.panel,.level-card,.lesson-row,.activity-card{border:1px solid var(--line);background:linear-gradient(145deg,rgba(255,255,255,.085),rgba(255,255,255,.035));box-shadow:var(--shadow);backdrop-filter:blur(18px);-webkit-backdrop-filter:blur(18px)}
.hero-main{border-radius:var(--r-xl);padding:clamp(26px,4vw,52px);position:relative;overflow:hidden}.hero-main::after{content:"日本語";position:absolute;right:-18px;bottom:-28px;font-family:var(--jp);font-size:clamp(72px,12vw,150px);font-weight:900;color:rgba(255,255,255,.035);transform:rotate(-5deg);pointer-events:none}
.kicker{display:inline-flex;align-items:center;gap:8px;color:#d7e2f2;font-size:12px;font-weight:850;letter-spacing:.12em;text-transform:uppercase}.kicker::before{content:"";width:30px;height:2px;background:linear-gradient(90deg,var(--gold),var(--cyan));border-radius:99px}
.hero h1{margin:18px 0 14px;font-size:clamp(42px,7vw,82px);line-height:.96;letter-spacing:-.045em;max-width:820px}.hero h1 .accent{background:linear-gradient(90deg,#fff4c2,var(--gold) 42%,var(--cyan));-webkit-background-clip:text;background-clip:text;color:transparent}
.lead{margin:0;max-width:720px;color:var(--muted);font-size:clamp(16px,1.7vw,20px);line-height:1.65}.hero-actions{display:flex;flex-wrap:wrap;gap:10px;margin-top:26px}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:10px;min-height:48px;padding:0 17px;border-radius:14px;text-decoration:none;font-weight:850;border:1px solid var(--line);background:rgba(255,255,255,.06)}.btn.primary{background:linear-gradient(135deg,#fff9df,#ffd166);color:#14233d;border-color:rgba(255,255,255,.5);box-shadow:0 12px 30px rgba(255,209,102,.18)}
.hero-side{border-radius:var(--r-xl);padding:24px;display:flex;flex-direction:column;justify-content:space-between;gap:18px}.metric{padding:16px;border-radius:18px;background:rgba(255,255,255,.045);border:1px solid var(--line)}.metric b{display:block;font-size:30px}.metric span{display:block;color:var(--muted);font-size:13px;margin-top:4px}
.section-head{display:flex;align-items:end;justify-content:space-between;gap:16px;margin:34px 0 14px}.section-head h2{margin:0;font-size:clamp(24px,3vw,36px)}.section-head p{margin:0;color:var(--muted);font-size:14px}
.level-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px}.level-card{position:relative;overflow:hidden;border-radius:var(--r-lg);padding:24px;text-decoration:none;min-height:190px;display:flex;flex-direction:column;justify-content:space-between;transition:transform .2s ease,border-color .2s ease,background .2s ease}.level-card:hover{transform:translateY(-3px);border-color:var(--line2);background:linear-gradient(145deg,rgba(255,255,255,.12),rgba(255,255,255,.05))}
.level-top{display:flex;align-items:center;justify-content:space-between;gap:12px}.level-badge{font-size:13px;font-weight:900;color:#13233e;background:var(--gold);padding:6px 9px;border-radius:999px}.status{font-size:12px;color:var(--muted)}.level-card h3{font-size:clamp(34px,5vw,54px);margin:24px 0 4px}.level-card p{margin:0;color:var(--muted);line-height:1.5}.level-card.soon{opacity:.58;pointer-events:none}.level-arrow{position:absolute;right:22px;bottom:20px;font-size:30px;color:var(--cyan)}
.breadcrumb{display:flex;align-items:center;gap:8px;flex-wrap:wrap;margin-bottom:18px;color:var(--muted);font-size:13px}.breadcrumb a{text-decoration:none;color:#dce6f4}.breadcrumb span{opacity:.65}
.page-head{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:18px;align-items:end;margin-bottom:22px}.page-head h1{margin:0;font-size:clamp(38px,6vw,68px);line-height:1;letter-spacing:-.035em}.page-head p{margin:10px 0 0;color:var(--muted);line-height:1.55}.pill{display:inline-flex;align-items:center;gap:8px;padding:9px 12px;border:1px solid var(--line);border-radius:999px;background:rgba(255,255,255,.05);font-size:12px;font-weight:800;color:#dbe5f4;white-space:nowrap}
.jump{margin-bottom:14px}.jump select{width:100%;min-height:48px;border:1px solid var(--line);border-radius:14px;background:#11213a;color:#fff;padding:0 14px;font:inherit;outline:none}.jump select:focus{border-color:rgba(126,231,242,.6);box-shadow:0 0 0 3px rgba(126,231,242,.10)}
.lesson-list{display:grid;gap:10px}.lesson-row{display:grid;grid-template-columns:74px minmax(0,1fr) auto;gap:14px;align-items:center;border-radius:18px;padding:14px 16px;text-decoration:none;box-shadow:none;transition:transform .18s ease,border-color .18s ease,background .18s ease}.lesson-row:hover{transform:translateX(3px);border-color:var(--line2);background:linear-gradient(145deg,rgba(255,255,255,.10),rgba(255,255,255,.045))}.lesson-row.disabled{opacity:.52;pointer-events:none}.lesson-num{font-size:12px;font-weight:950;letter-spacing:.08em;color:var(--gold)}.lesson-title{font-weight:850;font-size:17px}.lesson-sub{display:block;color:var(--muted);font-size:13px;margin-top:3px}.lesson-meta{display:flex;align-items:center;gap:8px}.dot{width:8px;height:8px;border-radius:50%;background:var(--mint);box-shadow:0 0 0 5px rgba(110,231,183,.08)}.dot.review{background:var(--gold)}.chev{font-size:25px;color:var(--cyan)}
.lesson-hero{border:1px solid var(--line);border-radius:var(--r-xl);padding:clamp(24px,4vw,42px);background:linear-gradient(145deg,rgba(255,255,255,.09),rgba(255,255,255,.035));box-shadow:var(--shadow);position:relative;overflow:hidden}.lesson-hero::after{content:"";position:absolute;width:280px;height:280px;border-radius:50%;right:-110px;top:-100px;background:radial-gradient(circle,rgba(126,231,242,.16),transparent 68%);pointer-events:none}.lesson-hero h1{margin:10px 0 6px;font-size:clamp(34px,6vw,64px);line-height:1.05;letter-spacing:-.035em}.lesson-hero .jp-title{font-family:var(--jp);font-size:clamp(20px,3vw,28px);color:#dce7f5}.lesson-hero .desc{margin:16px 0 0;color:var(--muted);line-height:1.65;max-width:760px}
.activity-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px;margin-top:18px}.activity-card{border-radius:20px;padding:20px;text-decoration:none;box-shadow:none;display:flex;flex-direction:column;min-height:180px;transition:transform .2s ease,border-color .2s ease,background .2s ease}.activity-card:hover{transform:translateY(-3px);border-color:var(--line2);background:linear-gradient(145deg,rgba(255,255,255,.11),rgba(255,255,255,.045))}.activity-icon{width:44px;height:44px;border-radius:14px;display:grid;place-items:center;background:linear-gradient(145deg,#fff9dd,#ffd166);color:#14233d;font-weight:950}.activity-card h2{font-size:19px;margin:18px 0 7px}.activity-card p{margin:0;color:var(--muted);line-height:1.45;font-size:14px}.activity-go{margin-top:auto;padding-top:18px;color:var(--cyan);font-weight:850;font-size:13px}
.note-card{margin-top:18px;border:1px solid var(--line);border-radius:18px;padding:15px 16px;color:var(--muted);background:rgba(255,255,255,.035);font-size:13px;line-height:1.55}.foot{margin-top:30px;padding-top:18px;border-top:1px solid rgba(255,255,255,.07);color:var(--soft);font-size:12px;display:flex;justify-content:space-between;gap:12px;flex-wrap:wrap}
@media (max-width:900px){
  .hero{grid-template-columns:1fr}.hero-side{display:grid;grid-template-columns:repeat(3,1fr)}.metric{min-width:0}
  .activity-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.page-head{grid-template-columns:1fr}.page-head .pill{justify-self:start}
}
@media (max-width:700px){
  .shell{padding-left:max(14px,env(safe-area-inset-left));padding-right:max(14px,env(safe-area-inset-right))}.topbar{margin-bottom:22px}.nav{display:none}
  .hero-main{padding:26px}.hero h1{font-size:clamp(42px,13vw,64px)}.hero-side{grid-template-columns:1fr 1fr}.hero-side .metric:last-child{grid-column:1/-1}
  .level-grid{grid-template-columns:1fr}.lesson-row{grid-template-columns:58px minmax(0,1fr) auto;padding:13px 13px}.lesson-title{font-size:16px}
  .activity-grid{grid-template-columns:1fr}.activity-card{min-height:150px}.foot{display:block}.foot span{display:block;margin-top:4px}
}
@media (max-width:380px){
  .shell{padding-left:max(11px,env(safe-area-inset-left));padding-right:max(11px,env(safe-area-inset-right))}.brandcopy span{display:none}.hero-main{padding:22px}.hero-side{grid-template-columns:1fr}
  .hero-side .metric:last-child{grid-column:auto}.hero-actions{display:grid}.btn{width:100%}.lesson-row{grid-template-columns:50px minmax(0,1fr) auto;gap:9px}.lesson-sub{font-size:12px}
}
@media (orientation:landscape) and (max-height:520px){
  .topbar{margin-bottom:16px}.hero{grid-template-columns:minmax(0,1.35fr) minmax(240px,.65fr)}.hero-main{padding:24px}.hero h1{font-size:clamp(38px,7vw,58px)}.lead{font-size:15px;line-height:1.45}.hero-actions{margin-top:16px}.hero-side{display:flex;padding:18px}.section-head{margin-top:22px}
}
@media (min-width:1500px){.shell{width:min(1280px,100%)}.hero-main{padding:56px}.lesson-list{gap:12px}.lesson-row{padding:16px 18px}}
@media (hover:none){.level-card:hover,.lesson-row:hover,.activity-card:hover{transform:none}}
@media (prefers-reduced-motion:reduce){*{scroll-behavior:auto!important}.level-card,.lesson-row,.activity-card{transition:none!important}}
:focus-visible{outline:3px solid rgba(126,231,242,.85);outline-offset:3px}
body{overflow-x:hidden}.hero-main,.hero-side,.level-card,.lesson-row,.activity-card,.page-head>*,.lesson-hero{min-width:0}.hero h1,.page-head h1,.lesson-hero h1,.lead,.lesson-title,.lesson-sub{overflow-wrap:anywhere;word-break:normal}

/* Public shell refinements: keep Vietnamese/UI on UI font and hero compact across viewport heights. */
.lesson-note{font-family:var(--ui)!important}
.hero-single{display:block;margin-bottom:28px}
.hero-single .hero-main{width:100%;max-width:none;min-height:0;padding:clamp(24px,3.2vw,44px)}
.hero-single h1{max-width:900px;font-size:clamp(42px,6vw,72px)}
.hero-single .lead{max-width:760px}
@media (max-height:700px) and (min-width:701px){
  .topbar{margin-bottom:20px}.hero-single{margin-bottom:20px}.hero-single .hero-main{padding:26px 38px}
  .hero-single h1{margin:12px 0 10px;font-size:clamp(40px,5vw,60px)}.hero-single .lead{font-size:16px;line-height:1.5}.hero-actions{margin-top:18px}
  .section-head{margin:24px 0 12px}.level-card{min-height:160px;padding:20px}
}