:root{
  --bg:#f3f2fc;--card:#ffffff;--ink:#241f3d;--muted:#7b769a;
  --brand:#6c5ce7;--brand-dark:#5a4bd4;--brand-grad:linear-gradient(135deg,#7b6cf6,#5a4bd4);
  --accent:#ff7a85;--line:#ece9f6;
  --good:#1aa179;--good-bg:#e4f7f0;--bad:#e1495b;--bad-bg:#fdeaec;--warn:#c98a1a;--warn-bg:#fdf3e0;
  --radius:18px;--shadow:0 10px 30px rgba(91,76,175,.10);
}
html[data-theme="dark"]{
  --bg:#15131f;--card:#1e1b2e;--ink:#e9e7f5;--muted:#a39ec2;
  --brand:#8b7cff;--brand-dark:#a99dff;--brand-grad:linear-gradient(135deg,#8b7cff,#6c5ce7);
  --accent:#ff8a94;--line:#2c2840;
  --good:#5fe3b0;--good-bg:#15302a;--bad:#f87171;--bad-bg:#3a1d24;--warn:#fbbf24;--warn-bg:#352c14;
  --shadow:0 10px 30px rgba(0,0,0,.35);
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--ink);line-height:1.55;
  font-family:"Plus Jakarta Sans",-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif}
a{color:var(--brand);text-decoration:none}a:hover{text-decoration:underline}
.nav{display:flex;align-items:center;justify-content:space-between;background:var(--card);
  border:1px solid var(--line);border-radius:999px;margin:14px auto 0;width:min(1100px,calc(100% - 32px));
  padding:10px 18px;position:sticky;top:12px;z-index:10;box-shadow:var(--shadow)}
.brand{font-weight:800;font-size:1.12rem;color:var(--ink)}
.nav-links{display:flex;gap:16px;align-items:center}
.nav-links a{color:var(--ink);font-weight:600;font-size:.92rem}
.nav-links a:hover{color:var(--brand);text-decoration:none}
.nav-links a.btn-sm,.nav-links a.btn-sm:hover{color:#fff}
.nav-links a.btn-ghost,.nav-links a.btn-ghost:hover{color:var(--brand-dark)}
.nav-user{color:var(--muted);font-size:.9rem}
.container{max-width:1000px;margin:22px auto;padding:0 18px}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:22px 24px;margin-bottom:16px;
  box-shadow:var(--shadow)}
h1{font-size:1.55rem;margin:.2em 0 .4em;letter-spacing:-.01em}h2{font-size:1.18rem;letter-spacing:-.01em}
.muted{color:var(--muted)}
.alert{border-radius:12px;padding:11px 14px;margin:10px 0;font-size:.92rem}
.alert.error{background:var(--bad-bg);color:var(--bad);border:1px solid rgba(225,73,91,.25)}
.alert.ok{background:var(--good-bg);color:var(--good);border:1px solid rgba(26,161,121,.25)}
label{display:block;font-size:.9rem;font-weight:600;margin:12px 0 0}
input,select,textarea{width:100%;padding:11px 13px;border:1px solid var(--line);border-radius:12px;font-size:.95rem;
  font-family:inherit;margin-top:6px;background:var(--card);color:var(--ink)}
textarea{min-height:90px;resize:vertical}
input:focus,select:focus,textarea:focus{outline:none;border-color:var(--brand);box-shadow:0 0 0 4px rgba(108,92,231,.15)}
button,.btn-primary,.btn-ghost,.btn-sm{font:inherit;font-weight:700;border:none;border-radius:999px;cursor:pointer;display:inline-block}
.btn-primary{background:var(--brand-grad);color:#fff;padding:11px 22px;box-shadow:0 6px 16px rgba(108,92,231,.30)}
.btn-primary:hover{filter:brightness(1.05);text-decoration:none}
.btn-ghost{background:rgba(108,92,231,.10);color:var(--brand-dark);padding:11px 22px}
.btn-ghost:hover{background:rgba(108,92,231,.18);text-decoration:none}
.btn-sm{background:var(--brand-grad);color:#fff;padding:7px 14px;font-size:.82rem;box-shadow:0 4px 12px rgba(108,92,231,.25)}
.btn-sm.ghost{background:rgba(108,92,231,.10);color:var(--brand-dark);box-shadow:none}
.btn-sm:hover{text-decoration:none;filter:brightness(1.05)}
.grid-2{display:grid;grid-template-columns:1fr 1fr;gap:14px}
.grid-4{display:grid;grid-template-columns:repeat(4,1fr);gap:14px}
@media(max-width:680px){.grid-2,.grid-4{grid-template-columns:1fr}}
.auth-card{max-width:460px;margin:30px auto}
/* split auth (login / register) */
.auth-split{max-width:900px;margin:34px auto;padding:0;overflow:hidden;display:grid;grid-template-columns:1.05fr 1fr}
.auth-aside{background:radial-gradient(130% 150% at 0% 0%,#8b7cff 0%,#6c5ce7 45%,#5a4bd4 100%);
  color:#fff;padding:40px 34px;display:flex;flex-direction:column;justify-content:center;gap:14px}
.auth-aside .auth-brand{font-weight:800;font-size:1.15rem;letter-spacing:-.01em}
.auth-aside h2{color:#fff;font-size:1.7rem;line-height:1.2;margin:6px 0 0;letter-spacing:-.01em}
.auth-aside p{color:rgba(255,255,255,.92);margin:0;font-size:.95rem}
.auth-points{list-style:none;padding:0;margin:10px 0 0;display:flex;flex-direction:column;gap:11px;font-weight:600;font-size:.92rem}
.auth-points li{display:flex;align-items:center;gap:8px}
.auth-main{padding:36px 34px;display:flex;flex-direction:column;justify-content:center}
.auth-main h1{margin:0 0 2px}
@media(max-width:760px){
  .auth-split{grid-template-columns:1fr;max-width:460px}
  .auth-aside{padding:26px 24px;gap:10px}
  .auth-aside h2{font-size:1.35rem}
  .auth-points{display:none}
  .auth-main{padding:26px 22px}
}
.hero{text-align:center;padding:52px 24px;border-radius:24px;color:#fff;
  background:radial-gradient(120% 140% at 0% 0%,#8b7cff 0%,#6c5ce7 45%,#5a4bd4 100%);box-shadow:var(--shadow)}
.hero h1{font-size:2.2rem;color:#fff}.hero p{color:rgba(255,255,255,.9);max-width:580px;margin:0 auto 22px}
.hero .btn-ghost{background:rgba(255,255,255,.18);color:#fff}
.hero .btn-ghost:hover{background:rgba(255,255,255,.28)}
.hero-actions{display:flex;gap:12px;flex-wrap:wrap;align-items:center;margin-top:8px}
.hero .hero-actions{justify-content:center}
.hero{position:relative;overflow:hidden}
.hero-deco{position:absolute;inset:0;z-index:0;pointer-events:none}
.hero-deco svg{width:100%;height:100%}
.hero>*:not(.hero-deco){position:relative;z-index:1}
/* two-column hero */
.hero-2col{display:grid;grid-template-columns:1.1fr .9fr;align-items:center;gap:28px;text-align:left;padding:54px 48px}
.hero-2col .hero-text h1{font-size:2.7rem;line-height:1.08;margin:.1em 0 .35em}
.hero-2col .hero-actions{justify-content:flex-start}
.hero-art svg{width:100%;height:auto;max-height:340px;display:block}
@media(max-width:820px){
  .hero-2col{grid-template-columns:1fr;text-align:center;padding:40px 22px}
  .hero-2col .hero-actions{justify-content:center}
  .hero-2col .hero-text h1{font-size:2rem}
  .hero-art{display:none}
}
/* growth journey */
.journey{margin:18px auto;padding:26px 24px}
.journey-svg{width:100%;height:auto;max-height:240px;margin:6px 0 4px;color:var(--ink)}
.journey-legend{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;text-align:center;color:var(--muted);font-size:.9rem}
.journey-legend b{color:var(--ink)}
@media(max-width:680px){.journey-legend{grid-template-columns:1fr;gap:8px}}
/* three ways */
.ways{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}
.way{text-align:center}
.way-art{width:100%;max-width:190px;height:auto;margin:0 auto 6px;display:block}
.way h3{margin:.2em 0}
@media(max-width:760px){.ways{grid-template-columns:1fr}}
/* personas */
.personas{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}
.persona{text-align:center}
.persona-emoji{font-size:2.4rem;line-height:1;margin-bottom:8px}
.persona h3{margin:.2em 0}
@media(max-width:760px){.personas{grid-template-columns:1fr}}
.hero-badge{display:inline-block;background:rgba(255,255,255,.18);color:#fff;font-weight:700;font-size:.78rem;
  padding:5px 13px;border-radius:999px;margin-bottom:14px;letter-spacing:.02em}
/* how it works */
.how{display:grid;grid-template-columns:1fr auto 1fr auto 1fr;align-items:center;gap:12px;margin-top:10px}
.how-step{text-align:center;padding:22px 18px;margin:0}
.how-step h4{margin:10px 0 4px;font-size:1.05rem}
.how-step p{margin:0;color:var(--muted);font-size:.9rem}
.how-ico{width:54px;height:54px;border-radius:16px;display:flex;align-items:center;justify-content:center;
  font-size:1.7rem;margin:0 auto}
.how-arrow{color:var(--brand);font-size:1.6rem;font-weight:800}
html[data-theme="dark"] .how-ico{filter:saturate(.7) brightness(.9)}
@media(max-width:760px){
  .how{grid-template-columns:1fr;gap:10px}
  .how-arrow{transform:rotate(90deg);justify-self:center}
}
/* feature icon chips */
.feat-ico{width:48px;height:48px;border-radius:14px;display:flex;align-items:center;justify-content:center;
  font-size:1.55rem;margin-bottom:10px}
html[data-theme="dark"] .feat-ico{filter:saturate(.7) brightness(.92)}
.section-title{text-align:center;margin:34px 0 6px;font-size:1.4rem;letter-spacing:-.01em}
/* live stats strip */
.stat-strip{display:grid;grid-template-columns:repeat(4,1fr);gap:10px;margin:18px auto;text-align:center;padding:22px 18px}
.stat-strip .stat-cell .n{font-size:1.9rem;font-weight:800;color:var(--brand-dark);line-height:1}
.stat-strip .stat-cell .l{font-size:.82rem;color:var(--muted);margin-top:6px;font-weight:600}
@media(max-width:600px){.stat-strip{grid-template-columns:1fr 1fr;gap:18px 10px}}
/* call-to-action band */
.cta-band{display:flex;align-items:center;justify-content:space-between;gap:18px;flex-wrap:wrap;margin-top:18px;
  background:radial-gradient(130% 200% at 0% 0%,rgba(139,124,255,.16),rgba(108,92,231,.05))}
.cta-band h2{margin:0}
.features{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;margin-top:16px}
@media(max-width:880px){.features{grid-template-columns:1fr 1fr}}
@media(max-width:600px){.features{grid-template-columns:1fr}}
.feature h3{margin:.2em 0}
.pill{display:inline-block;background:rgba(108,92,231,.12);color:var(--brand-dark);font-size:.78rem;padding:5px 12px;border-radius:999px;font-weight:700;margin-right:6px}
.pill.switch{background:rgba(108,92,231,.08)}
/* subject thumbnails */
.subj-head{display:flex;align-items:flex-start;justify-content:space-between;gap:12px;flex-wrap:wrap;margin-bottom:14px}
.subject-editor{border:1px solid var(--line);border-radius:14px;padding:14px 16px;margin-bottom:14px;background:var(--bg)}
.subj-checks{display:grid;grid-template-columns:repeat(auto-fill,minmax(160px,1fr));gap:8px 14px}
.subj-check{display:flex;align-items:center;gap:8px;font-weight:600;font-size:.92rem;margin:0}
.subj-check input{width:auto;margin:0}
.subject-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(170px,1fr));gap:14px}
.subject-tile{display:flex;flex-direction:column;gap:0;text-align:center;overflow:hidden;
  border:1px solid var(--line);border-radius:16px;background:var(--card);cursor:pointer;
  font-weight:700;box-shadow:0 4px 14px rgba(91,76,175,.06);transition:.15s}
.subject-tile:hover{transform:translateY(-2px);box-shadow:var(--shadow);border-color:var(--brand)}
.subject-tile .cover{display:flex;align-items:center;justify-content:center;height:96px;
  background-size:cover;background-position:center;background-color:#0d0b16}
.subject-tile .cover.gradient{background-image:radial-gradient(120% 140% at 0% 0%,#8b7cff,#5a4bd4)}
.subject-tile .cover .ico{font-size:2.4rem;line-height:1}
.subject-tile .nm{font-size:.95rem;padding:12px 10px}
.subject-tile.active{border-color:var(--brand);box-shadow:0 0 0 2px rgba(108,92,231,.20)}
.subject-tile.active .nm{background:rgba(108,92,231,.10)}
html[data-theme="dark"] .subject-tile.active .nm{background:#16233b}
.chapter-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:16px}
.chapter-card{border:1px solid var(--line);border-radius:16px;padding:16px;background:var(--card);
  box-shadow:0 4px 14px rgba(91,76,175,.06);transition:.15s}
.chapter-card:hover{transform:translateY(-2px);box-shadow:var(--shadow)}
.ch-meta{font-size:.82rem;color:var(--muted);margin:4px 0 10px}
.ch-foot{display:flex;justify-content:space-between;align-items:center;gap:8px;flex-wrap:wrap}
/* redesigned chapter card */
.ch-card{position:relative;display:flex;flex-direction:column;gap:12px;
  border:1px solid var(--line);border-radius:18px;padding:18px;background:var(--card);
  box-shadow:0 4px 14px rgba(91,76,175,.06);transition:.16s}
.ch-card{overflow:hidden}
.ch-card:hover{transform:translateY(-3px);box-shadow:var(--shadow);border-color:var(--brand)}
.ch-cover{position:relative;display:flex;align-items:flex-start;justify-content:space-between;gap:10px;
  aspect-ratio:16/9;padding:12px;margin:-18px -18px 8px;border-radius:18px 18px 0 0;
  background-size:cover;background-position:center;background-color:#0d0b16}
.ch-cover.gradient{background-image:radial-gradient(120% 140% at 0% 0%,#8b7cff,#5a4bd4)}
.ch-card-top{display:flex;align-items:center;justify-content:space-between;gap:10px}
.ch-no{display:inline-flex;align-items:center;justify-content:center;min-width:34px;height:34px;padding:0 8px;
  border-radius:11px;font-weight:800;font-size:.95rem;color:#fff;background:var(--brand-grad);
  box-shadow:0 4px 12px rgba(108,92,231,.30)}
.ch-cover .badge{align-self:flex-start;backdrop-filter:saturate(1.2)}
.ch-card .ch-title{font-size:1.05rem;font-weight:700;line-height:1.35;margin:0}
.ch-stats{display:flex;flex-wrap:wrap;gap:6px}
.ch-stats span{font-size:.74rem;font-weight:600;color:var(--muted);
  background:rgba(108,92,231,.07);border-radius:999px;padding:4px 10px}
html[data-theme="dark"] .ch-stats span{background:#22304a;color:#cdd9ee}
.ch-lesson{display:inline-flex;align-items:center;gap:6px;align-self:flex-start;
  font-size:.85rem;font-weight:700;color:var(--brand-dark);background:rgba(108,92,231,.10);
  border-radius:999px;padding:7px 14px;text-decoration:none;transition:.12s}
.ch-lesson:hover{background:rgba(108,92,231,.18);text-decoration:none}
html[data-theme="dark"] .ch-lesson{background:#243040;color:#cdd9ee}
.ch-actions{display:flex;flex-wrap:wrap;gap:8px;margin-top:auto;padding-top:12px;border-top:1px solid var(--line)}
.badge{font-size:.75rem;padding:3px 9px;border-radius:999px;font-weight:600}
.badge.good{background:var(--good-bg);color:var(--good)}.badge.warn{background:var(--warn-bg);color:var(--warn)}
.badge.none{background:rgba(108,92,231,.08);color:var(--muted)}
.q{}.q-text{font-weight:600}.q-num{color:var(--brand)}
.req{color:var(--bad)}
.opts{display:grid;gap:8px;margin-top:12px}
.opt{display:flex;gap:10px;align-items:flex-start;border:1px solid var(--line);border-radius:12px;padding:11px 13px;cursor:pointer;background:rgba(108,92,231,.04)}
.opt:hover{border-color:var(--brand);background:rgba(108,92,231,.09)}.opt input{width:auto;margin-top:3px}
.q.err{border-color:var(--bad);box-shadow:0 0 0 3px rgba(225,73,91,.12)}
.hint{font-size:.8rem;color:var(--muted);margin-top:6px}
.bar{position:sticky;bottom:0;background:var(--card);border:1px solid var(--line);border-radius:14px;padding:14px 18px;
  display:flex;gap:12px;align-items:center;box-shadow:var(--shadow)}
.quiz-head .crumbs{font-size:.82rem;color:var(--muted)}
.lang-pick{display:inline-flex;align-items:center;gap:4px;font-size:.85rem;color:var(--muted);margin-left:4px}
.lang-pick select{width:auto;display:inline-block;margin:0;padding:6px 10px;font-size:.85rem;border-radius:999px}
.result-banner{border-radius:18px;padding:28px;text-align:center;margin-bottom:16px}
.result-banner.good{background:var(--good-bg);color:var(--good)}
.result-banner.warn{background:var(--warn-bg);color:var(--warn)}
.result-banner.bad{background:var(--bad-bg);color:var(--bad)}
.result-banner .big{font-size:2.2rem;font-weight:800}
.result-banner .verdict{font-weight:600;margin-top:4px}
.review-item blockquote{border-left:3px solid var(--brand);margin:6px 0;padding:6px 12px;color:var(--ink);background:rgba(108,92,231,.05);border-radius:0 8px 8px 0}
.ans-good{color:var(--good)}.ans-bad{color:var(--bad)}.ans-warn{color:var(--warn)}.ans-correct{color:var(--good)}
details summary{cursor:pointer;color:var(--brand);font-size:.9rem}
.tbl{width:100%;border-collapse:collapse;font-size:.9rem}
.tbl th,.tbl td{text-align:left;padding:9px 10px;border-bottom:1px solid var(--line)}
.tbl th{color:var(--muted);font-weight:600}
.footer{text-align:center;color:var(--muted);font-size:.85rem;padding:24px}
.progress-line{font-weight:600}
/* theme toggle button */
.theme-toggle{background:transparent;border:1px solid var(--line);border-radius:999px;width:36px;height:36px;
  padding:0;font-size:1rem;line-height:1;cursor:pointer;color:var(--ink)}
.theme-toggle:hover{background:rgba(127,127,127,.12)}
body{transition:background .2s ease,color .2s ease}
/* dark-mode overrides for hardcoded light surfaces */
html[data-theme="dark"] .nav{background:var(--card)}
html[data-theme="dark"] input,html[data-theme="dark"] select,html[data-theme="dark"] textarea{background:#0f141b;color:var(--ink)}
html[data-theme="dark"] .opt,html[data-theme="dark"] .chapter-card,html[data-theme="dark"] .stat,
html[data-theme="dark"] .review-item blockquote,html[data-theme="dark"] .feature{background:#141b24}
html[data-theme="dark"] .opt:hover{background:#1c2530;border-color:#3a567f}
html[data-theme="dark"] .bar,html[data-theme="dark"] .stepper{background:var(--card)}
html[data-theme="dark"] .btn-ghost{background:#243040;color:var(--ink)}
html[data-theme="dark"] .btn-ghost:hover{background:#2c3a4a}
html[data-theme="dark"] .pill{background:#22304a;color:#cdd9ee}
html[data-theme="dark"] .pill.switch{background:#243040}
html[data-theme="dark"] .badge.none{background:#243040;color:var(--muted)}
html[data-theme="dark"] .progress-track,html[data-theme="dark"] .opt-key{background:#243040}
html[data-theme="dark"] .opts.big .opt:has(input:checked){background:#16233b}
html[data-theme="dark"] .dot{background:#33404f}
html[data-theme="dark"] .brand{color:var(--ink)}
/* quiz stepper */
.stepper{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:22px;box-shadow:0 1px 2px rgba(16,24,40,.04)}
.step-top{display:flex;justify-content:space-between;align-items:center;font-size:.85rem;color:var(--muted);font-weight:600}
.step-answered{color:var(--brand-dark)}
.progress-track{height:8px;background:rgba(108,92,231,.08);border-radius:999px;margin:10px 0 20px;overflow:hidden}
.progress-fill{height:100%;width:10%;background:var(--brand-grad);border-radius:999px;transition:width .3s ease}
.slide{display:none;animation:slidein .25s ease}
.slide.active{display:block}
@keyframes slidein{from{opacity:0;transform:translateX(12px)}to{opacity:1;transform:none}}
.slide-num{font-size:.78rem;font-weight:700;color:var(--brand);text-transform:uppercase;letter-spacing:.04em}
.slide-q{font-size:1.25rem;font-weight:700;margin:6px 0 18px;line-height:1.4}
.opts.big{display:grid;gap:12px}
.opts.big .opt{align-items:center;padding:14px 16px;border-radius:12px;font-size:1rem}
.opt-key{display:inline-flex;align-items:center;justify-content:center;width:28px;height:28px;border-radius:8px;
  background:rgba(108,92,231,.08);color:var(--brand-dark);font-weight:700;font-size:.85rem;flex:0 0 auto}
.opt input:checked ~ .opt-key,.opt.sel .opt-key{background:var(--brand);color:#fff}
.opts.big .opt:has(input:checked){border-color:var(--brand);background:rgba(108,92,231,.10);box-shadow:0 0 0 2px rgba(108,92,231,.18)}
.opt-text{flex:1}
.step-nav{display:flex;align-items:center;gap:12px;margin-top:22px}
.step-nav .btn-primary,.step-nav .btn-ghost{padding:11px 22px}
.step-nav #btn-back{margin-right:auto}
.step-nav #btn-next,.step-nav #btn-submit{margin-left:auto}
.dots{display:flex;gap:7px;flex-wrap:wrap;justify-content:center;flex:1}
.dot{width:11px;height:11px;border-radius:50%;background:#dfe5ee;cursor:pointer;transition:.15s}
.dot.done{background:#9bd3ad}
.dot.current{background:var(--brand);transform:scale(1.25)}
.step-warn{color:var(--bad);font-size:.88rem;margin:12px 0 0;text-align:right}
.step-foot{margin-top:14px;text-align:center;font-size:.85rem}
@media(max-width:600px){.slide-q{font-size:1.1rem}.dots{order:3;width:100%;margin-top:6px}}
.tag-new{display:inline-block;background:var(--accent);color:#fff;font-size:.62rem;font-weight:800;
  padding:1px 6px;border-radius:999px;margin-left:4px;vertical-align:middle;letter-spacing:.03em}
/* lesson player */
.lesson-top{display:flex;justify-content:space-between;align-items:center;font-size:.85rem;color:var(--muted);font-weight:600}
.ls-narr{display:flex;align-items:center;gap:6px;margin:0;font-weight:600}
.lesson-stage{min-height:300px;display:flex;align-items:center;justify-content:center;margin:18px 0;
  border-radius:16px;padding:28px;background:radial-gradient(120% 140% at 0% 0%,rgba(139,124,255,.16),rgba(108,92,231,.06))}
.lesson-start{text-align:center}
.ls-bigtitle{font-size:1.8rem;font-weight:800;margin-bottom:8px;letter-spacing:-.01em}
.lesson-slide{width:100%}
.lesson-slide.in .ls-heading{animation:slidein .35s ease}
.ls-heading{font-size:1.5rem;font-weight:800;margin-bottom:16px;color:var(--brand-dark)}
.ls-bullets{list-style:none;padding:0;margin:0;display:flex;flex-direction:column;gap:12px}
.ls-bullets li{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:13px 16px;font-size:1.05rem;
  font-weight:500;box-shadow:0 2px 8px rgba(91,76,175,.06);opacity:0;animation:bulletin .4s ease forwards}
@keyframes bulletin{from{opacity:0;transform:translateY(10px)}to{opacity:1;transform:none}}
/* level tabs */
.level-tabs{display:flex;gap:10px;margin-bottom:16px}
.level-tab{flex:1;display:flex;flex-direction:column;gap:2px;text-align:center;border:1px solid var(--line);
  border-radius:12px;padding:12px 10px;background:var(--card);color:var(--ink);text-decoration:none;transition:.12s}
.level-tab:hover{border-color:#b9c6e6;text-decoration:none}
.level-tab .lt-name{font-weight:700}
.level-tab .lt-meta{font-size:.78rem;color:var(--muted)}
.level-tab.current{border-color:var(--brand);background:rgba(108,92,231,.10);box-shadow:0 0 0 2px rgba(108,92,231,.18)}
html[data-theme="dark"] .level-tab.current{background:#16233b}
.level-tab.passed{border-color:#bfe5cb}
.level-tab.passed .lt-meta{color:var(--good)}
.level-tab.locked{opacity:.6;cursor:not-allowed;background:var(--bg)}
/* match — drag & drop */
.dnd-items{display:flex;flex-direction:column;gap:10px;margin-top:6px}
.dnd-item{display:flex;align-items:center;gap:12px;border:1px solid var(--line);border-radius:12px;padding:10px 12px;background:#fafbfe}
html[data-theme="dark"] .dnd-item{background:#141b24}
.dnd-badge{display:inline-flex;align-items:center;justify-content:center;width:26px;height:26px;flex:0 0 auto;
  border-radius:8px;background:rgba(108,92,231,.08);color:var(--brand-dark);font-weight:700;font-size:.82rem}
html[data-theme="dark"] .dnd-badge{background:#243040}
.dnd-left{flex:1;font-weight:600}
.dnd-slot{flex:0 0 44%;min-height:46px;border:2px dashed var(--line);border-radius:10px;
  display:flex;align-items:center;justify-content:center;padding:5px;transition:.12s}
.dnd-slot.over{border-color:var(--brand);background:rgba(108,92,231,.08)}
.dnd-slot.filled{border-style:solid;border-color:#bfe5cb}
.dnd-ph{color:var(--muted);font-size:.82rem}
.dnd-slot.filled .dnd-ph{display:none}
.dnd-pool{margin-top:16px;border:1px solid var(--line);border-radius:12px;padding:12px;background:var(--bg)}
.dnd-pool-label{font-size:.8rem;color:var(--muted);margin-bottom:10px}
.dnd-chips{display:flex;flex-wrap:wrap;gap:10px;min-height:44px}
.dnd-chip{background:var(--card);border:1px solid var(--line);border-radius:10px;padding:9px 14px;font-weight:600;
  cursor:grab;touch-action:none;user-select:none;box-shadow:0 1px 2px rgba(16,24,40,.06);transition:.12s}
.dnd-chip:hover{border-color:#b9c6e6}
.dnd-chip.armed{border-color:var(--brand);box-shadow:0 0 0 2px rgba(108,92,231,.22)}
.dnd-chip.dragging{opacity:.35}
.dnd-slot .dnd-chip{margin:0;box-shadow:none;background:rgba(108,92,231,.10);border-color:var(--brand)}
html[data-theme="dark"] .dnd-slot .dnd-chip{background:#16233b}
.dnd-ghost{position:fixed;z-index:1000;pointer-events:none;transform:translate(-50%,-50%);opacity:.95;
  box-shadow:0 8px 24px rgba(16,24,40,.25)}
@media(max-width:600px){.dnd-slot{flex-basis:40%}}
/* match the following */
.match-grid{display:grid;gap:12px;margin-top:6px}
.match-row{display:flex;gap:12px;align-items:center;border:1px solid var(--line);border-radius:12px;padding:12px 14px;background:#fafbfe}
html[data-theme="dark"] .match-row{background:#141b24}
.match-left{flex:1;font-weight:600;display:flex;align-items:center;gap:10px}
.match-num{display:inline-flex;align-items:center;justify-content:center;width:24px;height:24px;border-radius:7px;
  background:rgba(108,92,231,.08);color:var(--brand-dark);font-size:.8rem;font-weight:700;flex:0 0 auto}
html[data-theme="dark"] .match-num{background:#243040}
.match-sel{flex:0 0 46%;margin-top:0}
.match-review td{font-size:.88rem}
@media(max-width:600px){.match-row{flex-direction:column;align-items:stretch;gap:8px}.match-sel{flex:1}}
/* media library */
.media-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:16px}
.media-card{padding:0;overflow:hidden}
.media-thumb{background:#0d0b16;aspect-ratio:16/9;display:flex;align-items:center;justify-content:center}
.media-thumb video{width:100%;height:100%;object-fit:cover;display:block}
.media-novideo{display:flex;flex-direction:column;align-items:center;gap:8px;color:#fff;font-size:2rem;
  background:radial-gradient(120% 140% at 0% 0%,#8b7cff,#5a4bd4);width:100%;height:100%;justify-content:center}
.media-novideo span{font-size:.82rem;font-weight:600;opacity:.92}
.media-body{padding:14px 16px}
.media-card .ch-foot{margin-top:10px}
/* admin */
.admin-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:12px;margin-bottom:8px}
@media(max-width:680px){.admin-grid{grid-template-columns:1fr 1fr}}
.stat{background:#fafbfe;border:1px solid var(--line);border-radius:12px;padding:14px;text-align:center}
.stat .n{font-size:1.6rem;font-weight:800;color:var(--brand-dark)}
.inline-form{display:flex;gap:8px;align-items:flex-end;flex-wrap:wrap}
.inline-form label{margin:0}
/* profile avatar */
.avatar-lg{width:84px;height:84px;border-radius:50%;flex:none;background:var(--brand-grad);background-size:cover;background-position:center;
  color:#fff;display:flex;align-items:center;justify-content:center;font-size:2rem;font-weight:800;box-shadow:var(--shadow)}
/* profile page */
.profile-wrap{max-width:720px;margin:0 auto}
.profile-hero{display:flex;align-items:center;gap:20px;flex-wrap:wrap;
  background:radial-gradient(130% 160% at 0% 0%,#8b7cff,#6c5ce7 50%,#5a4bd4);color:#fff;border:none}
.profile-hero .avatar-lg.ring{width:88px;height:88px;border:3px solid rgba(255,255,255,.6)}
.profile-hero .ph-meta h1{color:#fff;margin:0 0 2px;font-size:1.5rem}
.profile-hero .ph-meta p{color:rgba(255,255,255,.92);margin:0 0 8px;font-size:.92rem}
.profile-hero .ph-pill{display:inline-block;background:rgba(255,255,255,.2);color:#fff;font-size:.74rem;font-weight:700;padding:4px 12px;border-radius:999px}
.sec-title{margin:0 0 12px;font-size:1.1rem}
.switch-row{display:flex;align-items:center;gap:10px;font-weight:600;margin-top:12px}
.switch-row input{width:auto;margin:0}
/* ============================================================
   Mobile / responsive
   ============================================================ */
@media(max-width:820px){
  /* Nav: stack the brand over wrapped links instead of one long pill */
  .nav{flex-direction:column;align-items:stretch;gap:10px;border-radius:18px;
       width:calc(100% - 24px);padding:12px 16px;position:static;top:auto}
  .nav-links{flex-wrap:wrap;justify-content:center;gap:10px 14px;row-gap:8px}
  .nav-links a{font-size:.9rem}
  .brand{text-align:center}

  .container{margin:16px auto;padding:0 14px}
  .card{padding:18px 16px}
  h1{font-size:1.35rem}
  .hero{padding:38px 18px}
  .hero h1{font-size:1.7rem}

  /* Wide tables scroll horizontally inside their card instead of squishing */
  .card{overflow-x:auto}
  .tbl{min-width:600px}

  /* Filter bar stacks full-width */
  .filters{flex-direction:column;align-items:stretch}
  .filters label{width:100%}
  .filters .hint{margin-left:0 !important}

  /* Toolbars wrap nicely */
  .hero-actions,.inline-form{width:100%}
  .pager{flex-wrap:wrap}
}
@media(max-width:480px){
  /* full-width submit only for auth forms (login/register), not inline rows */
  .auth-card .btn-primary{width:100%;text-align:center}
  .result-banner .big{font-size:1.8rem}
  h1{font-size:1.25rem}
}
/* ---- mobile UX polish ---- */
@media(hover:none){
  /* comfortable tap targets on touch devices */
  .btn-sm{padding:9px 15px}
  .btn-sm.btn-ic{width:36px;height:36px}
  .nav-links a{padding:4px 2px}
  .opt,.dnd-chip,.dnd-slot{min-height:46px}
}
@media(max-width:600px){
  /* tutor bot fills width nicely and sits above the FAB */
  #tutor-panel{right:12px;left:12px;width:auto;bottom:78px;max-height:70vh}
  #tutor-fab{right:14px;bottom:14px}
  /* video preview modal */
  .vid-modal{padding:10px}
  .vid-modal-box{padding:12px;border-radius:12px}
  /* subject tiles: 2-up on small screens */
  .subject-grid{grid-template-columns:repeat(auto-fill,minmax(135px,1fr));gap:10px}
  .subject-tile .cover{height:74px}
  /* chapter cards full width with comfortable spacing */
  .chapter-grid{grid-template-columns:1fr}
  /* quiz stepper actions wrap cleanly */
  .step-nav{flex-wrap:wrap;gap:10px}
  .step-nav .btn-primary,.step-nav .btn-ghost{flex:1;text-align:center}
  /* lesson player stage shorter on phones */
  .lesson-stage{min-height:220px;padding:18px}
  .ls-bigtitle{font-size:1.4rem}
}