:root{
  --paper:#F6EFE3;
  --paper-alt:#EDE2CC;
  --card:#FBF6EB;
  --ink:#332A20;
  --ink-soft:#786B5A;
  --teal:#2E7D5B;
  --teal-deep:#1F5A40;
  --amber:#C97A2E;
  --coral:#C05A3F;
  --success:#3D8B5F;
  --line:#DCCFB2;
  --radius:10px;
  --accent: var(--teal);
}
*{box-sizing:border-box;}
html{scroll-behavior:smooth;}
body{
  margin:0;color:var(--ink);
  font-family:'IBM Plex Sans',sans-serif;-webkit-font-smoothing:antialiased;
  background-color:var(--paper);
  background-image:
    radial-gradient(circle, rgba(51,42,32,0.05) 1px, transparent 1px);
  background-size:22px 22px;
}
h1,h2,h3{font-family:'Spectral',serif;margin:0;letter-spacing:-0.01em;}
.mono{font-family:'IBM Plex Mono',monospace;}
a{color:inherit;}
button{font-family:inherit;cursor:pointer;}
img{max-width:100%;}

/* ---------- top nav ---------- */
.topbar{position:sticky;top:0;z-index:60;background:var(--paper);border-bottom:1px solid var(--line);}
.topbar-inner{max-width:1180px;margin:0 auto;display:flex;align-items:center;justify-content:space-between;padding:14px 24px;gap:16px;flex-wrap:wrap;}
.brand{display:flex;align-items:center;gap:10px;text-decoration:none;}
.brand-mark{width:11px;height:11px;border-radius:50%;background:var(--coral);box-shadow:0 0 0 3px rgba(185,74,61,0.15);flex:none;}
.brand-name{font-size:1.1rem;font-weight:600;font-family:'Spectral',serif;}
.brand-sub{font-family:'IBM Plex Mono',monospace;font-size:0.65rem;color:var(--ink-soft);letter-spacing:0.08em;text-transform:uppercase;}
nav.tabs{display:flex;gap:4px;background:var(--paper-alt);padding:4px;border-radius:999px;flex-wrap:wrap;}
nav.tabs a, nav.tabs button{border:none;background:transparent;padding:8px 16px;border-radius:999px;font-size:0.82rem;font-weight:600;color:var(--ink-soft);text-decoration:none;transition:all .15s ease;display:inline-block;}
nav.tabs a.active, nav.tabs button.active{background:var(--ink);color:var(--paper);}
nav.tabs a:hover:not(.active), nav.tabs button:hover:not(.active){color:var(--ink);}

.wrap{max-width:1180px;margin:0 auto;padding:0 24px 80px;}

/* ---------- hero ---------- */
.eyebrow{font-family:'IBM Plex Mono',monospace;font-size:0.7rem;letter-spacing:0.12em;text-transform:uppercase;color:var(--teal);margin-bottom:12px;display:block;}
.hero{padding:52px 0 12px;}
.hero h1{font-size:2.3rem;font-weight:600;line-height:1.14;max-width:680px;}
.hero p{max-width:560px;color:var(--ink-soft);font-size:1rem;line-height:1.6;margin-top:14px;}

.ekg-wrap{width:100%;height:56px;margin:30px 0 6px;overflow:hidden;}
.ekg-wrap svg{width:100%;height:100%;display:block;}
.ekg-line{fill:none;stroke:var(--coral);stroke-width:2;stroke-linecap:round;stroke-linejoin:round;stroke-dasharray:1200;stroke-dashoffset:1200;animation:draw 2.2s ease-out forwards;}
@keyframes draw{to{stroke-dashoffset:0;}}
@media (prefers-reduced-motion: reduce){.ekg-line{animation:none;stroke-dashoffset:0;}}

.vitals{display:grid;grid-template-columns:repeat(3,1fr);gap:1px;background:var(--line);border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;margin:24px 0 8px;}
.vital{background:var(--card);padding:16px 18px;}
.vital-label{font-family:'IBM Plex Mono',monospace;font-size:0.64rem;letter-spacing:0.1em;text-transform:uppercase;color:var(--ink-soft);}
.vital-value{font-family:'IBM Plex Mono',monospace;font-size:1.5rem;font-weight:600;color:var(--teal-deep);margin-top:4px;}

/* ---------- section headers ---------- */
.section-head{display:flex;align-items:baseline;justify-content:space-between;margin:44px 0 18px;border-bottom:1px solid var(--line);padding-bottom:10px;flex-wrap:wrap;gap:8px;}
.section-head h2{font-size:1.3rem;font-weight:600;}
.section-head .count{font-family:'IBM Plex Mono',monospace;color:var(--ink-soft);font-size:0.78rem;}

/* ---------- week blocks ---------- */
@keyframes rise-in{from{opacity:0;transform:translateY(10px);}to{opacity:1;transform:translateY(0);}}
.week-block{margin-bottom:18px;border:1px solid var(--line);border-radius:var(--radius);background:var(--card);overflow:hidden;border-left:5px solid var(--wk-color, var(--teal));animation:rise-in .5s ease backwards;}
.week-block:nth-child(1){animation-delay:.03s;}
.week-block:nth-child(2){animation-delay:.09s;}
.week-block:nth-child(3){animation-delay:.15s;}
.week-block:nth-child(4){animation-delay:.21s;}
.week-block:nth-child(5){animation-delay:.27s;}
.week-block:nth-child(6){animation-delay:.33s;}
.week-block:nth-child(7){animation-delay:.39s;}
.week-head{display:flex;align-items:center;justify-content:space-between;padding:18px 22px;cursor:pointer;gap:14px;flex-wrap:wrap;}
.week-head:hover{background:rgba(51,42,32,0.03);}
.week-left{display:flex;align-items:baseline;gap:14px;}
.week-num{font-family:'IBM Plex Mono',monospace;font-size:0.72rem;color:var(--wk-color,var(--teal));font-weight:700;letter-spacing:.06em;}
.week-title{font-family:'Spectral',serif;font-size:1.2rem;font-weight:600;}
.week-status{font-family:'IBM Plex Mono',monospace;font-size:0.68rem;color:var(--ink-soft);text-transform:uppercase;letter-spacing:.06em;}
.week-caret{font-size:0.8rem;color:var(--ink-soft);transition:transform .2s ease;}
.week-block.open .week-caret{transform:rotate(90deg);}
.week-chapters{max-height:0;overflow:hidden;transition:max-height .25s ease;}
.week-block.open .week-chapters{max-height:2000px;}
.week-chapters-inner{padding:0 22px 20px;display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:12px;}
.week-empty{padding:0 22px 22px;color:var(--ink-soft);font-size:0.86rem;font-style:italic;}
.week-empty-card{margin:0 22px 22px;padding:16px 18px;border:1.5px dashed var(--line);border-radius:8px;display:flex;align-items:center;gap:14px;color:var(--ink-soft);font-size:0.85rem;line-height:1.5;background:repeating-linear-gradient(135deg, rgba(51,42,32,0.02), rgba(51,42,32,0.02) 8px, transparent 8px, transparent 16px);}
.week-empty-card svg{flex:none;color:var(--wk-color,var(--teal));opacity:0.6;}
.week-empty-card strong{color:var(--ink);}

.chapter-card{display:block;background:var(--paper);border:1px solid var(--line);border-radius:8px;padding:14px 16px;text-decoration:none;color:var(--ink);transition:transform .18s cubic-bezier(.34,1.56,.64,1), box-shadow .18s ease;}
.chapter-card:hover{transform:translateY(-3px) rotate(-0.4deg);box-shadow:0 10px 22px -12px rgba(51,42,32,0.3);border-color:var(--wk-color,var(--teal));}
.chapter-card:hover .chapter-icon-badge{transform:scale(1.12) rotate(-6deg);}
.chapter-num{font-family:'IBM Plex Mono',monospace;font-size:0.65rem;color:var(--wk-color,var(--teal));font-weight:700;text-transform:uppercase;letter-spacing:.06em;}
.chapter-title{font-family:'Spectral',serif;font-size:1.02rem;font-weight:600;margin-top:4px;line-height:1.3;}
.chapter-meta{font-size:0.76rem;color:var(--ink-soft);margin-top:6px;}

/* ---------- generic cards / buttons ---------- */
.btn{display:inline-flex;align-items:center;gap:8px;background:var(--ink);color:var(--paper);border:none;padding:11px 20px;border-radius:999px;font-size:0.85rem;font-weight:600;text-decoration:none;}
.btn:hover{background:var(--teal-deep);}
.btn-outline{background:transparent;color:var(--ink);border:1.5px solid var(--line);}
.btn-outline:hover{border-color:var(--teal);background:transparent;color:var(--ink);}

.placeholder-note{margin-top:36px;padding:16px 18px;border-radius:8px;border:1px solid var(--line);background:var(--paper-alt);font-size:0.82rem;color:var(--ink-soft);line-height:1.6;}
.placeholder-note strong{color:var(--ink);}
.placeholder-note code{background:var(--card);padding:1px 6px;border-radius:4px;}

footer{max-width:1180px;margin:0 auto;padding:30px 24px 60px;color:var(--ink-soft);font-size:0.76rem;font-family:'IBM Plex Mono',monospace;border-top:1px solid var(--line);display:flex;justify-content:space-between;flex-wrap:wrap;gap:8px;}

/* ---------- chapter page ---------- */
.chapter-hero{padding:40px 0 6px;border-bottom:none;}
.chapter-eyebrow{font-family:'IBM Plex Mono',monospace;font-size:0.68rem;text-transform:uppercase;letter-spacing:.1em;color:var(--accent);}
.chapter-hero h1{font-size:1.9rem;margin-top:8px;}
.chapter-tabs{display:flex;gap:6px;margin-top:26px;border-bottom:1px solid var(--line);flex-wrap:wrap;}
.chapter-tabs button{background:transparent;border:none;padding:12px 18px;font-size:0.86rem;font-weight:600;color:var(--ink-soft);border-bottom:2.5px solid transparent;margin-bottom:-1px;}
.chapter-tabs button.active{color:var(--ink);border-bottom-color:var(--accent);}
.chapter-panel{display:none;padding-top:24px;}
.chapter-panel.active{display:block;}

.guide-frame-wrap{border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;background:var(--card);}
.guide-frame-wrap iframe{width:100%;height:78vh;border:none;display:block;background:#fff;}

/* ---------- quiz ---------- */
.quiz-head{display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:14px;margin-bottom:10px;}
.quiz-monitor{display:flex;border:1px solid var(--line);border-radius:8px;overflow:hidden;font-family:'IBM Plex Mono',monospace;}
.quiz-monitor>div{padding:9px 14px;background:var(--card);border-right:1px solid var(--line);}
.quiz-monitor>div:last-child{border-right:none;}
.quiz-monitor .m-label{font-size:0.6rem;color:var(--ink-soft);text-transform:uppercase;letter-spacing:.08em;}
.quiz-monitor .m-value{font-size:1.02rem;font-weight:600;color:var(--teal-deep);}
.quiz-mode-toggle{display:flex;gap:4px;background:var(--paper-alt);padding:3px;border-radius:999px;}
.quiz-mode-toggle button{padding:7px 14px;border-radius:999px;border:none;background:transparent;font-size:0.78rem;font-weight:600;color:var(--ink-soft);}
.quiz-mode-toggle button.active{background:var(--ink);color:var(--paper);}

.quiz-card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:30px;}
.quiz-progress-track{height:4px;background:var(--paper-alt);border-radius:2px;overflow:hidden;margin-bottom:22px;}
.quiz-progress-fill{height:100%;background:var(--accent);width:0%;transition:width .3s ease;}
.quiz-tag{font-family:'IBM Plex Mono',monospace;font-size:0.66rem;color:var(--accent);text-transform:uppercase;letter-spacing:.08em;font-weight:700;}
.quiz-question{font-family:'Spectral',serif;font-size:1.25rem;font-weight:500;margin-top:10px;line-height:1.45;}
.quiz-options{display:flex;flex-direction:column;gap:10px;margin-top:22px;}
.quiz-option{text-align:left;padding:13px 15px;border-radius:8px;border:1.5px solid var(--line);background:var(--paper);font-size:0.92rem;display:flex;align-items:center;gap:12px;transition:border-color .15s ease, background .15s ease;}
.quiz-option .letter{font-family:'IBM Plex Mono',monospace;font-size:0.75rem;font-weight:700;width:21px;height:21px;border-radius:50%;border:1.5px solid var(--line);display:flex;align-items:center;justify-content:center;flex:none;color:var(--ink-soft);}
.quiz-option:hover:not(:disabled){border-color:var(--accent);}
.quiz-option.correct{border-color:var(--success);background:rgba(47,122,84,0.08);}
.quiz-option.correct .letter{background:var(--success);color:#fff;border-color:var(--success);}
.quiz-option.incorrect{border-color:var(--coral);background:rgba(185,74,61,0.08);}
.quiz-option.incorrect .letter{background:var(--coral);color:#fff;border-color:var(--coral);}
.quiz-option:disabled{cursor:default;}
.quiz-feedback{margin-top:18px;padding:13px 15px;border-radius:8px;font-size:0.86rem;line-height:1.6;display:none;}
.quiz-feedback.show{display:block;}
.quiz-feedback.correct-fb{background:rgba(47,122,84,0.08);color:var(--teal-deep);}
.quiz-feedback.incorrect-fb{background:rgba(185,74,61,0.08);color:var(--coral);}
.quiz-actions{display:flex;justify-content:flex-end;margin-top:20px;}
.btn-next{background:var(--ink);color:var(--paper);border:none;padding:10px 20px;border-radius:999px;font-size:0.83rem;font-weight:600;}
.btn-next:disabled{opacity:0.35;cursor:default;}
.btn-next:hover:not(:disabled){background:var(--teal-deep);}
.quiz-done{text-align:center;padding:36px 16px;}
.quiz-done .score-big{font-family:'IBM Plex Mono',monospace;font-size:2.4rem;font-weight:700;color:var(--teal-deep);margin:12px 0;}
.btn-restart{background:var(--accent);color:#fff;border:none;padding:10px 22px;border-radius:999px;font-size:0.83rem;font-weight:600;margin-top:8px;}

/* ---------- teach back ---------- */
.teachback-card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:28px;}
.teachback-prompt{font-family:'Spectral',serif;font-size:1.2rem;line-height:1.5;margin-bottom:16px;}
.teachback-card textarea{width:100%;min-height:160px;border:1.5px solid var(--line);border-radius:8px;padding:14px;font-family:'IBM Plex Sans',sans-serif;font-size:0.92rem;background:var(--paper);resize:vertical;line-height:1.6;}
.teachback-card textarea:focus{outline:2px solid var(--accent);outline-offset:1px;}
.teachback-actions{display:flex;justify-content:space-between;align-items:center;margin-top:16px;flex-wrap:wrap;gap:10px;}
.teachback-hint{font-size:0.78rem;color:var(--ink-soft);}
.teachback-response{margin-top:20px;padding:18px;border-radius:8px;background:var(--paper-alt);font-size:0.9rem;line-height:1.7;display:none;white-space:pre-wrap;}
.teachback-response.show{display:block;}
.teachback-terms{margin-top:22px;padding-top:18px;border-top:1px dashed var(--line);}
.teachback-terms .term-chip{display:inline-block;background:var(--paper);border:1px solid var(--line);border-radius:999px;padding:5px 12px;font-size:0.76rem;margin:3px 4px 3px 0;font-family:'IBM Plex Mono',monospace;}

/* ---------- glossary page ---------- */
.glossary-search{position:relative;margin-top:24px;}
.glossary-search input{width:100%;padding:14px 18px;border-radius:999px;border:1.5px solid var(--line);background:var(--card);font-size:0.95rem;font-family:'IBM Plex Sans',sans-serif;}
.glossary-search input:focus{outline:2px solid var(--teal);outline-offset:1px;}
.glossary-results{margin-top:22px;display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:12px;}
.gterm-card{background:var(--card);border:1px solid var(--line);border-radius:8px;padding:16px;border-left:3px solid var(--wk-color,var(--teal));}
.gterm-name{font-family:'Spectral',serif;font-weight:600;font-size:1rem;}
.gterm-def{font-size:0.86rem;color:var(--ink-soft);margin-top:6px;line-height:1.55;}
.gterm-src{margin-top:8px;font-family:'IBM Plex Mono',monospace;font-size:0.64rem;color:var(--accent);text-transform:uppercase;letter-spacing:.06em;}

/* ---------- chapter roadmap diagram ---------- */
.chapter-map{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:22px 24px;margin-bottom:22px;border-left:4px solid var(--map-color,var(--accent));}
.map-title{font-family:'IBM Plex Mono',monospace;font-size:0.68rem;text-transform:uppercase;letter-spacing:.1em;color:var(--map-color,var(--accent));font-weight:700;margin-bottom:14px;}
.map-flow{display:flex;flex-direction:column;gap:0;}
.map-row{display:flex;align-items:stretch;flex-wrap:wrap;gap:0;}
.map-row.reversed{flex-direction:row-reverse;}
.map-node{background:var(--paper);border:1.5px solid var(--line);border-radius:8px;padding:10px 12px;min-width:120px;flex:1;}
.map-node-num{font-family:'IBM Plex Mono',monospace;font-size:0.6rem;color:var(--map-color,var(--accent));font-weight:700;}
.map-node-label{font-size:0.8rem;font-weight:600;margin-top:3px;line-height:1.3;}
.map-arrow{display:flex;align-items:center;justify-content:center;width:26px;flex:none;color:var(--ink-soft);font-size:0.9rem;}
.map-row.reversed .map-arrow{transform:scaleX(-1);}
.map-drop{text-align:center;color:var(--ink-soft);font-size:0.9rem;padding:2px 0;}
@media (max-width:700px){
  .map-row, .map-row.reversed{flex-direction:column;}
  .map-arrow{transform:rotate(90deg);width:auto;padding:2px 0;}
  .map-row.reversed .map-arrow{transform:rotate(90deg) scaleX(-1);}
}

/* ---------- week icons on cards ---------- */
.week-left{align-items:center;}
.week-icon svg{width:100%;height:100%;display:block;}
.chapter-icon-badge{width:44px;height:44px;border-radius:10px;background:var(--card);border:1.5px solid var(--line);display:flex;align-items:center;justify-content:center;color:var(--accent);flex:none;transition:transform .18s cubic-bezier(.34,1.56,.64,1);}
@keyframes gentle-bob{0%,100%{transform:translateY(0);}50%{transform:translateY(-3px);}}
.week-head .chapter-icon-badge{animation:gentle-bob 3.4s ease-in-out infinite;}
.week-block:nth-child(2n) .week-head .chapter-icon-badge{animation-delay:.6s;}
.week-block:nth-child(3n) .week-head .chapter-icon-badge{animation-delay:1.1s;}
.week-head:hover .chapter-icon-badge{animation-play-state:paused;transform:scale(1.1) rotate(-5deg);}
.chapter-hero-top{display:flex;align-items:center;gap:14px;}
.chapter-card .system-tag-row{display:flex;margin-bottom:6px;align-items:center;gap:8px;}

/* ---------- quiz progress ring ---------- */
.quiz-head-ring{display:flex;align-items:center;gap:14px;}
.progress-ring{flex:none;}
.progress-ring circle{transition:stroke-dashoffset .3s ease;}

/* ---------- native guide content (restyled study guide, in-theme) ---------- */
.guide-native{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:34px 38px 50px;}
.guide-native section.block{margin-bottom:48px;scroll-margin-top:16px;}
.guide-native section.block:last-child{margin-bottom:0;}
.guide-native .block-head{display:flex;align-items:baseline;gap:12px;border-bottom:2px solid var(--accent, var(--teal));padding-bottom:8px;margin-bottom:16px;flex-wrap:wrap;}
.guide-native .block-head h2{font-family:'Spectral',serif;font-size:1.4rem;margin:0;color:var(--ink);font-weight:600;}
.guide-native .block-head .tag{font-size:0.68rem;text-transform:uppercase;letter-spacing:.08em;color:var(--accent, var(--teal));background:color-mix(in srgb, var(--accent, var(--teal)) 14%, transparent);padding:3px 10px;border-radius:12px;font-family:'IBM Plex Mono',monospace;}
.guide-native .block-intro{color:var(--ink-soft);margin-bottom:18px;font-size:0.92rem;}

.guide-native details.topic{background:var(--paper);border:1px solid var(--line);border-radius:10px;margin-bottom:12px;overflow:hidden;}
.guide-native details.topic > summary{list-style:none;cursor:pointer;padding:13px 18px;font-family:'Spectral',serif;font-size:1.05rem;color:var(--ink);display:flex;justify-content:space-between;align-items:center;background:linear-gradient(to right, color-mix(in srgb, var(--accent, var(--teal)) 10%, transparent), transparent 70%);}
.guide-native details.topic > summary::-webkit-details-marker{display:none;}
.guide-native details.topic > summary::after{content:"+";font-family:'IBM Plex Sans',sans-serif;font-size:1.2rem;color:var(--accent, var(--teal));transition:transform .15s ease;}
.guide-native details.topic[open] > summary::after{transform:rotate(45deg);}
.guide-native .topic-body{padding:4px 20px 16px;}

.guide-native .fact-grid{display:grid;grid-template-columns:1fr 1fr;gap:11px;margin:10px 0 14px;}
@media (max-width:640px){.guide-native .fact-grid{grid-template-columns:1fr;}}
.guide-native .fact{background:var(--card);border:1px solid var(--line);border-left:4px solid var(--accent, var(--teal));border-radius:6px;padding:10px 12px;}
.guide-native .fact.warn{border-left-color:var(--coral);}
.guide-native .fact.tx{border-left-color:var(--amber);}
.guide-native .fact h4{margin:0 0 4px;font-size:0.66rem;text-transform:uppercase;letter-spacing:.07em;color:var(--accent, var(--teal));font-family:'IBM Plex Mono',monospace;}
.guide-native .fact.warn h4{color:var(--coral);}
.guide-native .fact.tx h4{color:var(--amber);}
.guide-native .fact p, .guide-native .fact ul{margin:0;font-size:0.87rem;color:var(--ink);line-height:1.55;}
.guide-native .fact ul{padding-left:18px;}
.guide-native .fact li{margin-bottom:3px;}

.guide-native .callout{background:rgba(201,122,46,0.1);border:1px solid rgba(201,122,46,0.3);border-radius:8px;padding:10px 14px;font-size:0.85rem;margin-top:10px;line-height:1.55;}
.guide-native .callout b{color:var(--amber);}
.guide-native .danger{background:rgba(185,74,61,0.08);border:1px solid rgba(185,74,61,0.28);border-radius:8px;padding:10px 14px;font-size:0.85rem;margin-top:10px;line-height:1.55;}
.guide-native .danger b{color:var(--coral);}

.guide-native .gloss-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:11px;}
.guide-native .term{background:var(--paper);border:1px solid var(--line);border-radius:8px;padding:12px 14px;}
.guide-native .term dt{font-weight:700;font-size:0.9rem;color:var(--accent, var(--teal));margin-bottom:3px;font-family:'Spectral',serif;}
.guide-native .term dd{margin:0;font-size:0.83rem;color:var(--ink-soft);line-height:1.5;}

.guide-native .mindmap{background:var(--paper);border:1px solid var(--line);border-radius:12px;padding:18px 14px 12px;margin:20px 0 26px;}
.guide-native .mindmap .mm-title{font-family:'Spectral',serif;font-size:0.98rem;color:var(--ink);margin:0 0 8px 6px;}
.guide-native .mindmap svg{width:100%;height:auto;display:block;}
.guide-native .mm-node rect{fill:var(--accent, var(--teal));}
.guide-native .mm-node text{fill:#fff;font-family:'IBM Plex Sans',sans-serif;font-weight:600;}
.guide-native .mm-leaf rect{fill:color-mix(in srgb, var(--accent, var(--teal)) 14%, var(--paper));stroke:var(--accent, var(--teal));stroke-width:1;}
.guide-native .mm-leaf text{fill:var(--ink);font-family:'IBM Plex Sans',sans-serif;font-weight:400;}
.guide-native .mm-line{stroke:var(--line);stroke-width:1.6;}
.guide-native .mm-sub text{fill:var(--ink-soft);font-family:'IBM Plex Sans',sans-serif;}

.guide-native .recap{background:color-mix(in srgb, var(--accent, var(--teal)) 6%, var(--card));border:1px dashed var(--accent, var(--teal));border-radius:10px;padding:13px 17px;margin-top:10px;}
.guide-native .recap h4{margin:0 0 6px;font-size:0.7rem;text-transform:uppercase;letter-spacing:.07em;color:var(--accent, var(--teal));font-family:'IBM Plex Mono',monospace;}
.guide-native .recap ul{margin:0;padding-left:18px;font-size:0.85rem;}
.guide-native .recap li{margin-bottom:4px;}

.guide-native table.compare{width:100%;border-collapse:collapse;margin:12px 0;font-size:0.85rem;}
.guide-native table.compare th, .guide-native table.compare td{border:1px solid var(--line);padding:8px 10px;text-align:left;}
.guide-native table.compare th{background:color-mix(in srgb, var(--accent, var(--teal)) 12%, transparent);color:var(--accent, var(--teal));font-family:'IBM Plex Mono',monospace;font-size:0.72rem;text-transform:uppercase;letter-spacing:.05em;}

#ai-chat-toggle{position:fixed;bottom:22px;right:22px;z-index:200;background:var(--ink);color:var(--paper);border:none;width:54px;height:54px;border-radius:50%;font-size:1.3rem;box-shadow:0 10px 24px -8px rgba(51,42,32,0.32);}
#ai-chat-toggle:hover{background:var(--teal-deep);}
#ai-chat-panel{position:fixed;bottom:88px;right:22px;z-index:200;width:360px;max-width:calc(100vw - 32px);height:480px;max-height:calc(100vh - 140px);background:var(--card);border:1px solid var(--line);border-radius:14px;box-shadow:0 20px 50px -12px rgba(51,42,32,0.28);display:none;flex-direction:column;overflow:hidden;}
#ai-chat-panel.open{display:flex;}
.ai-chat-head{padding:14px 16px;background:var(--ink);color:var(--paper);display:flex;align-items:center;justify-content:space-between;}
.ai-chat-head-title{font-family:'Spectral',serif;font-size:0.95rem;}
.ai-chat-head-title .dot{display:inline-block;width:7px;height:7px;border-radius:50%;background:var(--coral);margin-right:8px;}
.ai-chat-settings-btn{background:transparent;border:none;color:var(--paper);opacity:0.75;font-size:0.9rem;}
.ai-chat-settings-btn:hover{opacity:1;}
.ai-chat-body{flex:1;overflow-y:auto;padding:14px 16px;display:flex;flex-direction:column;gap:10px;}
.ai-msg{font-size:0.86rem;line-height:1.55;padding:10px 13px;border-radius:10px;max-width:88%;}
.ai-msg.user{align-self:flex-end;background:var(--teal);color:#fff;border-bottom-right-radius:2px;}
.ai-msg.bot{align-self:flex-start;background:var(--paper-alt);color:var(--ink);border-bottom-left-radius:2px;white-space:pre-wrap;}
.ai-msg.system{align-self:center;background:transparent;color:var(--ink-soft);font-family:'IBM Plex Mono',monospace;font-size:0.72rem;text-align:center;}
.ai-chat-input-row{display:flex;border-top:1px solid var(--line);padding:10px;gap:8px;}
.ai-chat-input-row input{flex:1;border:1px solid var(--line);border-radius:999px;padding:9px 14px;font-size:0.85rem;font-family:inherit;background:var(--paper);}
.ai-chat-input-row button{background:var(--ink);color:var(--paper);border:none;border-radius:999px;padding:9px 16px;font-size:0.8rem;font-weight:600;}
.ai-chat-input-row button:disabled{opacity:0.4;}

.ai-settings-modal{position:fixed;inset:0;background:rgba(51,42,32,0.45);z-index:300;display:none;align-items:center;justify-content:center;padding:20px;}
.ai-settings-modal.open{display:flex;}
.ai-settings-box{background:var(--card);border-radius:14px;padding:26px;max-width:420px;width:100%;box-shadow:0 24px 60px -12px rgba(51,42,32,0.32);}
.ai-settings-box h3{font-size:1.2rem;margin-bottom:6px;}
.ai-settings-box p{font-size:0.84rem;color:var(--ink-soft);line-height:1.6;margin-top:8px;}
.ai-settings-box input{width:100%;padding:11px 14px;border-radius:8px;border:1.5px solid var(--line);margin-top:14px;font-family:'IBM Plex Mono',monospace;font-size:0.85rem;}
.ai-settings-actions{display:flex;gap:10px;margin-top:18px;justify-content:flex-end;}
.ai-warn{margin-top:14px;padding:10px 12px;border-radius:8px;background:rgba(201,122,46,0.12);color:var(--amber);font-size:0.76rem;line-height:1.5;}

/* ---------- AI tutor (per-chapter) ---------- */
.tutor-card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:28px;}
.tutor-head{display:flex;align-items:center;justify-content:space-between;margin-bottom:14px;flex-wrap:wrap;gap:8px;}
.tutor-messages{display:flex;flex-direction:column;gap:12px;max-height:480px;overflow-y:auto;padding:4px 2px;}
.tutor-messages .ai-msg{max-width:82%;}
.tutor-input-row{display:flex;gap:8px;margin-top:16px;border-top:1px solid var(--line);padding-top:14px;}
.tutor-input-row input{flex:1;border:1.5px solid var(--line);border-radius:999px;padding:11px 16px;font-size:0.9rem;font-family:inherit;background:var(--paper);}
.tutor-input-row button{background:var(--ink);color:var(--paper);border:none;border-radius:999px;padding:11px 20px;font-size:0.85rem;font-weight:600;}
.tutor-input-row button:hover{background:var(--teal-deep);}

/* ---------- final exam prep ---------- */
.fe-week-picker{display:flex;flex-direction:column;gap:8px;margin-top:20px;}
.fe-week-chip{display:flex;align-items:center;gap:10px;padding:10px 14px;border:1.5px solid var(--line);border-radius:8px;font-size:0.86rem;cursor:pointer;transition:border-color .12s ease;}
.fe-week-chip:hover{border-color:var(--wk-color,var(--teal));}
.fe-week-chip input{accent-color:var(--wk-color,var(--teal));width:16px;height:16px;flex:none;}
.fe-config-row{display:flex;gap:20px;margin-top:22px;flex-wrap:wrap;}
.fe-label{display:block;font-family:'IBM Plex Mono',monospace;font-size:0.68rem;text-transform:uppercase;letter-spacing:.07em;color:var(--ink-soft);margin-bottom:6px;}
.fe-select{padding:9px 14px;border-radius:8px;border:1.5px solid var(--line);background:var(--paper);font-family:inherit;font-size:0.86rem;color:var(--ink);min-width:180px;}
.fe-week-breakdown{margin-top:26px;display:flex;flex-direction:column;gap:12px;}
.fe-week-row{display:grid;grid-template-columns:1fr 2fr auto;gap:12px;align-items:center;}
.fe-week-row-label{font-size:0.82rem;font-weight:600;}
.fe-week-row-bar-track{height:8px;background:var(--paper-alt);border-radius:4px;overflow:hidden;}
.fe-week-row-bar{height:100%;border-radius:4px;transition:width .6s ease;}
.fe-week-row-pct{font-size:0.76rem;color:var(--ink-soft);white-space:nowrap;}
@media (max-width:600px){.fe-week-row{grid-template-columns:1fr;gap:4px;}}

/* ---------- flashcards ---------- */
.flashcard-count{text-align:center;color:var(--ink-soft);font-size:0.78rem;margin-bottom:18px;}
.flashcard-stage{perspective:1400px;max-width:520px;margin:0 auto;cursor:pointer;}
.flashcard{position:relative;width:100%;height:280px;transform-style:preserve-3d;transition:transform .5s cubic-bezier(.4,.2,.2,1);}
.flashcard.flipped{transform:rotateY(180deg);}
.flashcard-face{position:absolute;inset:0;backface-visibility:hidden;border-radius:14px;border:1.5px solid var(--line);display:flex;flex-direction:column;align-items:center;justify-content:center;padding:28px;text-align:center;gap:14px;}
.flashcard-front{background:var(--card);box-shadow:0 10px 26px -14px rgba(51,42,32,0.3);}
.flashcard-back{background:var(--accent, var(--teal));color:#fff;transform:rotateY(180deg);}
.flashcard-hint{font-family:'IBM Plex Mono',monospace;font-size:0.65rem;letter-spacing:.12em;opacity:0.6;}
.flashcard-text{font-family:'Spectral',serif;font-size:1.5rem;font-weight:600;line-height:1.3;}
.flashcard-def{font-size:1.05rem;font-weight:400;}
.flashcard-tap{font-family:'IBM Plex Mono',monospace;font-size:0.68rem;color:var(--ink-soft);opacity:0.7;}
.flashcard-actions{display:flex;justify-content:center;gap:12px;margin-top:24px;}

/* ---------- celebration confetti ---------- */
#confetti-layer{position:fixed;inset:0;pointer-events:none;z-index:400;overflow:hidden;}
.confetti-piece{position:absolute;top:-14px;border-radius:2px;animation:confetti-fall linear forwards;}
@keyframes confetti-fall{
  0%{transform:translateY(0) rotate(0deg);opacity:1;}
  100%{transform:translateY(105vh) rotate(var(--spin,360deg));opacity:0.85;}
}

@media (max-width:760px){
  .topbar-inner{flex-direction:column;align-items:flex-start;}
  nav.tabs{width:100%;}
  .hero h1{font-size:1.8rem;}
  .vitals{grid-template-columns:1fr;}
  #ai-chat-panel{right:12px;left:12px;width:auto;}
  #ai-chat-toggle{right:16px;bottom:16px;}
}