:root{
  --navy:#1a2744; --blue:#3b82f6; --blue-dark:#2563eb; --blue-light:#60a5fa;
  --bg:#f1f5f9; --card:#ffffff; --ink:#0f172a; --muted:#64748b;
  --mn-bg:#fef3c7; --mn-bd:#f59e0b; --tip-bg:#f8fafc; --tip-bd:#3b82f6;
  --ok-bg:#f0fdf4; --ok-bd:#22c55e; --bad:#ef4444;
  --radius:14px; --ease:cubic-bezier(.4,0,.2,1);
}
*{box-sizing:border-box}
body{margin:0;font-family:Inter,system-ui,-apple-system,Segoe UI,Roboto,sans-serif;background:var(--bg);color:var(--ink)}
.topbar{display:flex;justify-content:space-between;align-items:center;background:var(--navy);color:#fff;padding:14px 20px;position:sticky;top:0;z-index:5}
.brand{font-weight:800;font-size:18px;letter-spacing:.2px}
.brand-r{color:var(--blue-light)}
.brand .sub{color:#94a3b8;font-weight:600;margin-left:4px}
.streak{font-weight:700;font-size:14px;color:#fde68a}
.wrap{max-width:760px;margin:0 auto;padding:22px 18px 30px}
.foot{background:#1a2744;padding:24px 18px 28px;display:flex;flex-direction:column;align-items:center;gap:8px;text-align:center;color:#94a3b8}
.foot-brand{font-weight:800;font-size:16px;color:#fff}
.foot-brand .r{color:#60a5fa}
.foot-brand .sub{color:#94a3b8;font-weight:600}
.foot-tag{margin:0;font-weight:700;font-size:13px;color:#cbd5e1}
.foot-legal{margin:0;font-size:12px;line-height:1.5;color:#94a3b8;max-width:46ch}
.foot-links{font-size:12px;color:#94a3b8}
.foot-links a{color:#93c5fd;text-decoration:underline;text-underline-offset:2px}
.foot-links a:hover{color:#bfdbfe}
.foot-links a:focus-visible{outline:2px solid var(--blue-light);outline-offset:2px}
.foot-disclaimer{margin:0;font-size:11px;line-height:1.5;color:#94a3b8;max-width:62ch}
.foot-reset{display:inline-flex;align-items:center;gap:6px;margin-top:6px;background:#f59e0b;color:#1a2744;border:none;border-radius:999px;padding:10px 18px;min-height:44px;font-weight:700;font-size:13px;cursor:pointer;font-family:inherit;transition:background .2s var(--ease)}
.foot-reset:hover{background:#d97706}
.foot-reset:focus-visible{outline:2px solid var(--blue-light);outline-offset:2px}
.link{display:inline-flex;align-items:center;min-height:44px;background:none;border:none;color:var(--muted);cursor:pointer;text-decoration:underline;font-size:13px}

/* home */
.hero{background:var(--navy);color:#fff;border-radius:var(--radius);padding:26px 24px;margin-bottom:18px}
.hero .count{font-size:46px;font-weight:800;line-height:1}
.hero .count small{font-size:16px;font-weight:600;color:var(--blue-light)}
.hero .mastered{margin-top:10px;font-size:15px;color:#cbd5e1}
.bar{height:10px;background:#27406b;border-radius:6px;margin-top:14px;overflow:hidden}
.bar > i{display:block;height:100%;background:var(--blue);transition:width .4s var(--ease)}
.picker{display:flex;gap:10px;flex-wrap:wrap;margin:16px 0}
.btn{border:none;border-radius:12px;padding:13px 18px;font-weight:700;font-size:15px;cursor:pointer;transition:transform .15s var(--ease),box-shadow .2s var(--ease)}
.btn:hover{transform:translateY(-2px)}
.btn-primary{background:var(--blue);color:#fff}
.btn-primary:hover{background:var(--blue-dark)}
.btn-ghost{background:#fff;color:var(--navy);border:1px solid #e2e8f0}
.row{display:flex;gap:10px;align-items:center;flex-wrap:wrap}
.chip{font-size:12px;font-weight:700;padding:4px 10px;border-radius:999px;background:#e0ecff;color:var(--blue-dark)}
.chip.high{background:#dcfce7;color:#15803d}

/* session card */
.card{background:var(--card);border-radius:var(--radius);box-shadow:0 1px 3px rgba(15,23,42,.08);padding:22px;margin-bottom:16px;border:1px solid #eef2f7;transition:transform .25s var(--ease),box-shadow .25s var(--ease)}
.meta{display:flex;justify-content:space-between;align-items:center;margin-bottom:8px}
.topic{font-size:13px;font-weight:700;color:var(--muted)}
.cue{font-size:19px;font-weight:700;margin:6px 0 14px}
.concepts{margin:0;padding-left:18px}
.concepts li{margin:6px 0}
.mnem{background:var(--mn-bg);border:1px solid var(--mn-bd);border-radius:10px;padding:12px 14px;margin:12px 0}
.tip{background:var(--tip-bg);border:1px solid #bfdbfe;border-radius:8px;padding:10px 14px;margin:12px 0;font-size:14px}
.answer{background:var(--ok-bg);border:1px solid var(--ok-bd);border-radius:10px;padding:12px 14px;margin:12px 0}
.steps{font-family:ui-monospace,Consolas,monospace;font-size:13px;background:#0f172a;color:#e2e8f0;border-radius:10px;padding:12px 14px;white-space:pre-wrap}
.opt{display:block;width:100%;text-align:left;border:1px solid #e2e8f0;background:#fff;border-radius:10px;padding:12px 14px;margin:8px 0;cursor:pointer;font-size:15px;transition:border-color .15s}
.opt:hover{border-color:var(--blue)}
.opt.correct{background:var(--ok-bg);border-color:var(--ok-bd)}
.opt.wrong{background:#fef2f2;border-color:var(--bad)}
.blank{display:inline-block;min-width:90px;border-bottom:2px solid var(--blue);text-align:center;font-weight:700;color:var(--blue-dark)}
.ratings{display:grid;grid-template-columns:repeat(4,1fr);gap:8px;margin-top:8px}
.rate{border:1px solid #e2e8f0;background:#fff;border-radius:10px;padding:10px 6px;cursor:pointer;text-align:center}
.rate b{display:block;font-size:14px}
.rate small{color:var(--muted);font-size:11px}
.rate.again{border-color:#fecaca}.rate.hard{border-color:#fde68a}.rate.good{border-color:#bfdbfe}.rate.easy{border-color:#bbf7d0}
.progress-line{height:6px;background:#e2e8f0;border-radius:4px;margin:0 0 16px}
.progress-line > i{display:block;height:100%;background:var(--blue);border-radius:4px;transition:width .3s var(--ease)}
.occ{position:relative;display:inline-block;max-width:100%}
.occ .mask{position:absolute;background:var(--navy);color:#fff;display:flex;align-items:center;justify-content:center;border-radius:6px;cursor:pointer;font-size:12px;font-weight:700}
.occ .mask.revealed{background:var(--ok-bg);color:var(--navy);border:1px solid var(--ok-bd)}
.muted{color:var(--muted)} .center{text-align:center} .big{font-size:30px;font-weight:800}
audio{width:100%;margin-top:10px}
.kbd{font-family:ui-monospace,monospace;background:#eef2f7;border-radius:6px;padding:1px 6px;font-size:12px}

/* Phase A — renderers for the remaining item types + keyboard-visible focus (WCAG AA) */
.brain{width:100%;border:1px solid #e2e8f0;border-radius:10px;padding:10px 12px;font:inherit;font-size:15px;margin-top:6px;resize:vertical}
.brain:focus{outline:2px solid var(--blue);outline-offset:1px;border-color:var(--blue)}
.cc{width:100%;border-collapse:collapse;font-size:14px}
.cc th,.cc td{border:1px solid #e2e8f0;padding:8px 10px;text-align:left;vertical-align:top}
.cc thead th{background:#eef2f7;color:var(--navy)}
.sc-row{display:flex;gap:10px;align-items:center;justify-content:space-between;margin:8px 0}
.sc-item{font-weight:600}
.sc-sel{padding:8px 10px;border:1px solid #e2e8f0;border-radius:10px;font:inherit;font-size:14px;background:#fff}
.sc-sel.sc-ok{background:var(--ok-bg);border-color:var(--ok-bd)}
.sc-sel.sc-bad{background:#fef2f2;border-color:var(--bad)}
.occ .mask{border:0;font:inherit;line-height:1}
.occ .mask:focus-visible,.opt:focus-visible,.rate:focus-visible,.btn:focus-visible,.link:focus-visible{outline:2px solid var(--blue-light);outline-offset:2px}

/* ===================== Home / Hub dashboard (Today | Progress) ===================== */
:root{
  --slate:#334155; --green:#16a34a; --green-bg:#f0fdf4; --green-bd:#bbf7d0;
  --amber-bg:#fffbeb; --amber-bd:#fde68a; --amber-ink:#b45309;
  --warn-bg:#fff7ed; --warn-bd:#fed7aa; --warn-ink:#c2410c;
  --blue-soft:#eef4ff; --blue-bd:#dbeafe; --r-sm:8px; --r-md:12px;
}
.hint{font-size:13px;margin:6px 0 0}
.small{font-size:12px}
.muted .muted,.stat-hint{color:var(--muted)}
.btn-sm{display:inline-flex;align-items:center;justify-content:center;min-height:44px;padding:8px 15px;font-size:13px;border-radius:var(--r-sm)}

/* tabs */
.tabbar{display:flex;gap:6px;background:#e7edf5;border-radius:var(--radius);padding:5px;margin-bottom:16px}
.tab{flex:1;min-height:44px;border:none;background:transparent;color:var(--slate);font-weight:700;font-size:15px;border-radius:10px;cursor:pointer;transition:background .2s var(--ease),color .2s var(--ease)}
.tab:hover{color:var(--navy)}
.tab.is-active{background:#fff;color:var(--navy);box-shadow:0 1px 3px rgba(15,23,42,.1)}
.tab:focus-visible{outline:2px solid var(--blue-light);outline-offset:2px}
.pane[hidden]{display:none}

/* pace / hero card */
.hero-card{background:var(--navy);color:#fff;border:none}
.hero-card .topic{color:var(--blue-light)}
.count-line{display:flex;align-items:baseline;gap:8px}
.count-line .count{font-size:44px;font-weight:800;line-height:1}
.count-line .count-sub{font-size:15px;font-weight:600;color:var(--blue-light)}
.pace-pill{display:inline-flex;align-items:center;gap:7px;margin-top:12px;padding:7px 13px;border-radius:999px;font-size:13px;font-weight:700;border:1px solid transparent}
.pace--blue{background:rgba(96,165,250,.16);color:#bfdbfe;border-color:rgba(96,165,250,.4)}
.pace--ok{background:rgba(34,197,94,.16);color:#bbf7d0;border-color:rgba(34,197,94,.45)}
.pace--warn{background:rgba(245,158,11,.18);color:#fde68a;border-color:rgba(245,158,11,.5)}
.mastered-line{margin-top:14px;font-size:14px;color:#cbd5e1}
.hero-card .bar{height:10px;background:#27406b;border-radius:6px;margin-top:10px;overflow:hidden}
.hero-card .bar > i{display:block;height:100%;background:var(--blue);transition:width .4s var(--ease)}
.date-in{padding:11px;border:1px solid #e2e8f0;border-radius:10px;font:inherit;min-height:44px}
.hero-card .date-in{background:#fff;color:var(--ink)}

/* stat row */
.statrow{display:grid;grid-template-columns:repeat(4,1fr);gap:10px;margin-bottom:16px}
.stat{display:flex;flex-direction:column;align-items:flex-start;gap:2px;background:var(--card);border:1px solid #eef2f7;border-radius:var(--r-md);padding:13px 14px;min-height:84px;cursor:default;text-align:left;box-shadow:0 1px 3px rgba(15,23,42,.06)}
.stat:not([disabled]){cursor:pointer;transition:border-color .15s var(--ease),transform .15s var(--ease)}
.stat:not([disabled]):hover{border-color:var(--blue);transform:translateY(-2px)}
.stat:focus-visible{outline:2px solid var(--blue-light);outline-offset:2px}
.stat-val{font-size:26px;font-weight:800;color:var(--navy);line-height:1.05}
.stat-label{font-size:12px;font-weight:700;color:var(--slate)}
.stat-hint{font-size:11px}
@media(max-width:560px){.statrow{grid-template-columns:repeat(2,1fr)}}

.launch-meta{margin-top:12px}

/* accessible progress bars (text value + non-color cue, bar is decorative) */
.pbar-wrap{margin:10px 0}
.pbar-head{display:flex;justify-content:space-between;align-items:baseline;gap:10px;font-size:13px;margin-bottom:5px}
.pbar-label{font-weight:700;color:var(--slate)}
.pbar-val{font-weight:700;color:var(--navy);white-space:nowrap}
.pbar-done{color:var(--green);font-weight:800}
.pbar{height:9px;background:#e7edf5;border-radius:6px;overflow:hidden}
.pbar > i{display:block;height:100%;border-radius:6px;transition:width .4s var(--ease)}
.pbar--blue > i{background:var(--blue)}
.pbar--green > i{background:var(--green)}
.pbar--amber > i{background:#f59e0b}
.pbar.is-full > i{background:var(--green)}

/* weekly planner */
.planner{display:grid;gap:8px;margin-top:10px}
.plan-day{display:grid;grid-template-columns:46px 1fr;gap:10px;align-items:center}
.plan-name{font-weight:700;font-size:13px;color:var(--slate)}
.plan-in{width:100%;border:1px solid #e2e8f0;border-radius:var(--r-sm);padding:10px 11px;font:inherit;font-size:13px;min-height:44px;background:#fff;color:var(--ink)}
.plan-in:focus{outline:2px solid var(--blue);outline-offset:1px;border-color:var(--blue)}

/* multi-section hub strip */
.hub-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:10px;margin-top:12px}
.hub-card{border:1px solid #e2e8f0;border-radius:var(--r-md);padding:14px}
.hub--live{border-color:var(--blue);background:var(--blue-soft);box-shadow:0 1px 3px rgba(37,99,235,.12)}
.hub--next{background:#f8fafc;border-style:dashed}
.hub-top{display:flex;justify-content:space-between;align-items:center;gap:8px}
.hub-code{font-weight:800;font-size:17px;color:var(--navy)}
.hub--next .hub-code{color:var(--muted)}
.hub-name{margin-top:6px;font-size:13px;color:var(--slate);line-height:1.35}
.hub--next .hub-name{color:var(--muted)}
.hub-soon{font-size:11px;font-weight:700;margin-top:6px;text-transform:uppercase;letter-spacing:.4px}
.hub-later{margin-top:12px;font-size:12px;line-height:1.5}
.hub-later-label{font-weight:700;color:var(--slate)}
.npill{display:inline-flex;align-items:center;gap:4px;font-size:11px;font-weight:700;padding:2px 9px;border-radius:999px;white-space:nowrap}
.npill.live{background:#dcfce7;color:#15803d}
.npill.soon{background:#eef2f7;color:var(--muted)}

/* per-topic mastery rows */
.topic-row{display:block;width:100%;text-align:left;background:#fff;border:1px solid #eef2f7;border-radius:var(--r-md);padding:13px 15px;margin:10px 0;cursor:pointer;transition:border-color .15s var(--ease)}
.topic-row:hover{border-color:var(--blue)}
.topic-row:focus-visible{outline:2px solid var(--blue-light);outline-offset:2px}
.topic-row .pbar-wrap:first-child{margin-top:0}
.topic-row .pbar-wrap:last-child{margin-bottom:0}

/* achievements */
.ach-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:10px;margin-top:12px}
.ach{display:flex;flex-direction:column;gap:3px;border:1px solid #eef2f7;border-radius:var(--r-md);padding:13px}
.ach--on{background:var(--amber-bg);border-color:var(--amber-bd)}
.ach--off{background:#f8fafc;opacity:.72}
.ach-mark{font-size:18px;line-height:1}
.ach--on .ach-mark{color:#d97706}
.ach-label{font-weight:700;font-size:14px;color:var(--navy)}
.ach--off .ach-label{color:var(--slate)}
.ach-hint{font-size:11px;line-height:1.35}

/* session history */
.hist{list-style:none;margin:12px 0 0;padding:0}
.hist-row{display:flex;justify-content:space-between;align-items:baseline;gap:12px;padding:10px 0;border-bottom:1px solid #eef2f7;font-size:13px}
.hist-row:last-child{border-bottom:none}
.hist-date{font-weight:700;color:var(--navy)}
.hist-meta{font-size:12px}

/* success callout (full border + tint + leading icon — no side stripes) */
.callout-ok{background:var(--green-bg);border:1px solid var(--green-bd);border-radius:var(--r-sm);padding:11px 14px;margin:12px 0;font-size:14px}

/* session exit / back affordance (non-destructive return home) + item counter */
.session-top{display:flex;align-items:center;justify-content:space-between;margin-bottom:8px}
.session-exit{display:inline-flex;align-items:center;gap:6px;min-height:44px;padding:8px 8px 8px 4px;background:none;border:none;color:var(--muted);font:inherit;font-weight:700;font-size:14px;cursor:pointer;border-radius:var(--r-sm);transition:color .15s var(--ease)}
.session-exit:hover{color:var(--navy)}
.session-exit:focus-visible{outline:2px solid var(--blue-light);outline-offset:2px}
.session-count{font-size:13px;font-weight:700;color:var(--muted)}

/* stacked Coverage+Mastery bar (Progress tab) + legend */
.bar-legend{display:flex;gap:16px;margin:8px 0 14px;font-size:12px;font-weight:600;color:var(--slate)}
.lg{display:inline-flex;align-items:center;gap:6px}
.lg::before{content:"";width:11px;height:11px;border-radius:3px;display:inline-block}
.lg-mas::before{background:var(--green)}
.lg-cov::before{background:#bfdbfe}
.sbar{position:relative;height:11px;background:#e7edf5;border-radius:6px;overflow:hidden}
.sbar > i{position:absolute;left:0;top:0;height:100%;border-radius:6px;transition:width .4s var(--ease)}
.sbar-cov{background:#bfdbfe;z-index:1}
.sbar-mas{background:var(--green);z-index:2}

/* weekly planner — summary + distribution strip + collapsible editor */
.plan-summary{margin:4px 0 0;font-size:14px;color:var(--slate)}
.plan-summary b{color:var(--navy)}
.week-strip{display:flex;gap:6px;margin:11px 0 12px}
.wk-day{display:flex;flex-direction:column;align-items:center;gap:3px;flex:1}
.wk-i{font-size:11px;font-weight:700;color:var(--muted)}
.wk-dot{font-size:12px;line-height:1;color:#cbd5e1}
.wk-dot.on{color:var(--blue)}
.plan-devs{margin:2px 0 0;font-size:13px;color:var(--slate)}
.plan-devs-label{font-weight:700;color:var(--navy)}
.plan-none{margin:2px 0 0}
.plan-edit{margin-top:10px;border-top:1px solid #eef2f7;padding-top:4px}
.plan-edit > summary{cursor:pointer;font-weight:700;font-size:13px;color:var(--blue-d);list-style:none;min-height:44px;display:inline-flex;align-items:center;gap:7px}
.plan-edit > summary::-webkit-details-marker{display:none}
.plan-edit > summary::before{content:"▸";transition:transform .15s var(--ease)}
.plan-edit[open] > summary::before{transform:rotate(90deg)}
.plan-edit > summary:focus-visible{outline:2px solid var(--blue-light);outline-offset:2px}

@media(prefers-reduced-motion:reduce){
  *{transition:none!important;animation:none!important}
  .btn:hover,.stat:not([disabled]):hover{transform:none}
}

/* ---- paywall: two-tier choice-ladder ---- */
.paywall .big{margin-bottom:4px}
.tier-ladder{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:12px;margin:14px 0;text-align:left}
.tier{border:1px solid var(--blue-bd);border-radius:var(--r-md);padding:14px;background:var(--card);display:flex;flex-direction:column;gap:6px}
.tier--featured{border-color:var(--blue);box-shadow:0 0 0 1px var(--blue) inset}
.tier-badge{align-self:flex-start;font-size:11px;font-weight:700;letter-spacing:.02em;color:#fff;background:var(--blue);border-radius:999px;padding:2px 10px}
.tier-name{font-weight:700;color:var(--navy)}
.tier-price{font-size:26px;font-weight:800;color:var(--navy);line-height:1}
.tier-desc{margin:0}
.tier .btn{margin-top:auto}

/* ---- mnemonic acronym breakdown (vertical, bold initials) ---- */
.acronym{margin:4px 0}
.acr-row{padding:3px 0;font-size:15px;line-height:1.45;color:var(--ink)}
.acr-row strong{color:var(--navy)}
.acr-note{font-size:13px;line-height:1.5}

/* ---- first-run notice (config-driven front-matter disclaimers) ---- */
.firstrun-p{font-size:13px;line-height:1.6;color:var(--ink);margin:10px 0}
.firstrun .btn{margin-top:6px}

/* ---- retest + first-try layer cards ---- */
.retest-card{background:var(--amber-bg);border:1px solid var(--amber-bd)}
.firsttry .chip.high{background:var(--green-bg);border:1px solid var(--green-bd);color:var(--green)}