@import url('fonts.css');
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
:root{
  --bg:#EAF1F6;--surface:#FFFFFF;--surface2:#F1F6F9;--surface3:#E3ECF2;
  --text:#0A1828;--text2:#3C4E62;--text3:#7C8FA3;
  --accent:#B8860B;--accent2:#A9741E;--accent-bg:#FBF3E0;
  --green:#2E7D5B;--red:#C05A74;--amber:#B8860B;
  --border:#DDE7EE;--border2:#CBD9E2;
  --shadow-sm:0 1px 2px rgba(10,24,40,.06),0 1px 3px rgba(10,24,40,.08);
  --shadow:0 4px 14px rgba(10,24,40,.08),0 1px 3px rgba(10,24,40,.04);
  --shadow-lg:0 16px 40px rgba(10,24,40,.13),0 4px 10px rgba(10,24,40,.05);
  --radius:16px;--radius-sm:10px;--radius-lg:22px;
  --font:"EB Garamond","Songti SC","SimSun","宋体",serif;
  --font-heading:"Bodoni Moda SC","Playfair Display","Songti SC","SimSun","宋体",serif;
  --font-script:"Pinyon Script","Snell Roundhand",cursive;
  --font-caps:"Cinzel","Songti SC","SimSun","宋体",serif;
  --font-subhead:"Playfair Display","Bodoni Moda SC","Songti SC","SimSun","宋体",serif;
  --max-w:820px;
}
html{scroll-behavior:smooth;font-size:16px}
body{font-family:var(--font);background:var(--bg);color:var(--text);line-height:1.7;transition:background .3s,color .3s}
body.lang-en .cn{display:none!important}
body.lang-zh .en-text{display:none!important}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}
img{max-width:100%;border-radius:var(--radius)}
table{width:100%;border-collapse:collapse;margin:1rem 0;font-size:.92rem}
th,td{padding:.55rem .75rem;border:1px solid var(--border);text-align:left}
th{background:var(--surface2);font-weight:600}
tr:nth-child(even){background:var(--surface2)}

/* ── Dark ── */
body.dark{
  --bg:#0A1828;--surface:#0F2238;--surface2:#14304A;--surface3:#1A3D5C;
  --text:#F1E9D0;--text2:#CDC49E;--text3:#938C6E;
  --accent:#E8C87A;--accent2:#F1DCA0;--accent-bg:#3A3520;
  --green:#B8C97D;--red:#D98A6B;--amber:#E8C87A;
  --border:#1B3A55;--border2:#264B6B;
  --shadow-sm:0 1px 2px rgba(0,0,0,.4);
  --shadow:0 4px 16px rgba(0,0,0,.42);
  --shadow-lg:0 16px 40px rgba(0,0,0,.55);
  --accent-glow:rgba(232,200,122,.28);
}

/* ── Layout ── */
.container{max-width:var(--max-w);margin:0 auto;padding:0 1.25rem}
header{position:sticky;top:0;z-index:150;background:var(--surface);border-bottom:1px solid var(--border);backdrop-filter:blur(12px)}
.header-inner{display:flex;align-items:center;justify-content:space-between;padding:.75rem 0}
.logo{font-size:1.05rem;font-weight:700;color:var(--text)}
.logo span{color:var(--accent)}
.header-actions{display:flex;gap:.5rem;align-items:center}
.btn-icon{width:36px;height:36px;border-radius:50%;border:1px solid var(--border);background:var(--surface);color:var(--text);cursor:pointer;display:flex;align-items:center;justify-content:center;font-size:1.1rem;transition:all .2s}
.btn-icon:hover{background:var(--accent-bg);border-color:var(--accent)}
nav{background:var(--surface);border-bottom:1px solid var(--border);overflow-x:auto;-webkit-overflow-scrolling:touch}
nav ul{display:flex;gap:0;list-style:none;min-width:max-content}
nav a{display:block;padding:.65rem 1rem;font-size:.88rem;font-weight:500;color:var(--text2);transition:all .2s;border-bottom:2px solid transparent;white-space:nowrap}
nav a:hover,nav a.active{color:var(--accent);border-bottom-color:var(--accent);text-decoration:none}

/* ── Hero ── */
.hero{padding:3.5rem 0 2.5rem;text-align:center}
.hero h1{font-size:clamp(1.8rem,4vw,2.8rem);font-weight:800;line-height:1.2;margin-bottom:.75rem}
.hero h1 span{background:linear-gradient(135deg,var(--accent),#7c3aed);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}
.hero p{font-size:1.1rem;color:var(--text2);max-width:580px;margin:0 auto}

/* ── Sections ── */
section{padding:3rem 0 2rem;border-bottom:1px solid var(--border)}
section:last-of-type{border-bottom:none}
.section-label{display:inline-block;font-size:.75rem;font-weight:700;text-transform:uppercase;letter-spacing:.08em;color:var(--accent);background:var(--accent-bg);padding:.25rem .7rem;border-radius:20px;margin-bottom:.75rem}
h2{font-size:1.6rem;font-weight:700;margin-bottom:.5rem}
h3{font-size:1.2rem;font-weight:600;margin:1.5rem 0 .5rem;color:var(--text)}
h4{font-size:1.05rem;font-weight:600;margin:1.2rem 0 .4rem}
p{margin-bottom:.85rem}
.cn{color:var(--text2);font-size:.93rem;margin-bottom:.85rem}
.quote{border-left:3px solid var(--accent);padding:.75rem 1rem;margin:1rem 0;background:var(--accent-bg);border-radius:0 var(--radius-sm) var(--radius-sm) 0;font-style:italic}

/* ── Accordion ── */
.accordion{margin:1rem 0}
.acc-item{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-sm);margin-bottom:.5rem;overflow:hidden}
.acc-header{padding:.75rem 1rem;cursor:pointer;font-weight:600;font-size:.95rem;display:flex;align-items:center;justify-content:space-between;user-select:none;transition:background .2s}
.acc-header:hover{background:var(--surface2)}
.acc-header::after{content:"▸";font-size:1.1rem;transition:transform .25s;color:var(--text3)}
.acc-item.open .acc-header::after{transform:rotate(90deg)}
.acc-body{max-height:0;overflow:hidden;transition:max-height .35s ease}
.acc-body-inner{padding:.5rem 1rem 1rem;font-size:.93rem;line-height:1.7}

/* ── Tabs for debates ── */
.tabs{margin:1.25rem 0;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);overflow:hidden}
.tab-nav{display:flex;border-bottom:1px solid var(--border);overflow-x:auto}
.tab-btn{flex:1;padding:.65rem .75rem;font-size:.85rem;font-weight:600;border:none;background:none;cursor:pointer;color:var(--text2);border-bottom:2px solid transparent;transition:all .2s;white-space:nowrap}
.tab-btn:hover{background:var(--surface2)}
.tab-btn.active{color:var(--accent);border-bottom-color:var(--accent);background:var(--accent-bg)}
.tab-panel{display:none;padding:1rem 1.25rem;font-size:.93rem;line-height:1.7}
.tab-panel.active{display:block}
.tab-panel.side-a-tab{border-left:3px solid var(--green)}
.tab-panel.side-b-tab{border-left:3px solid var(--red)}
.tab-panel.verdict-tab{border-left:3px solid var(--accent);background:var(--accent-bg)}

/* ── Quiz ── */
.quiz{background:var(--surface);border:2px solid var(--border);border-radius:var(--radius);padding:1.5rem;margin:1.5rem 0}
.quiz-title{font-weight:700;font-size:1.1rem;margin-bottom:1rem;display:flex;align-items:center;gap:.5rem}
.quiz-item{margin-bottom:1.25rem;padding-bottom:1.25rem;border-bottom:1px solid var(--border)}
.quiz-item:last-child{border-bottom:none;margin-bottom:0;padding-bottom:0}
.q-tag{display:inline-block;font-size:.7rem;font-weight:700;text-transform:uppercase;letter-spacing:.05em;padding:.15rem .5rem;border-radius:4px;margin-bottom:.3rem}
.q-mechanism{background:#dbeafe;color:#1d4ed8}
.q-data{background:#fef3c7;color:#92400e}
.q-transfer{background:#d1fae5;color:#065f46}
.q-flaw{background:#ffe4e6;color:#9f1239}
.q-scenario{background:#e0e7ff;color:#3730a3}
.q-explain{background:#f0fdf4;color:#166534}
.q-calculate{background:#fef9c3;color:#854d0e}
.q-debate{background:#fce7f3;color:#9d174d}
.q-clinical{background:#ecfeff;color:#155e75}
.q-hydration{background:#dbeafe;color:#1e40af}
.q-plan{background:#f3e8ff;color:#6b21a8}
.q-career{background:#fff7ed;color:#9a3412}
.q-pyramid{background:#fefce8;color:#854d0e}
.q-application{background:#f0fdf4;color:#166534}
.q-reveal{display:none;margin-top:.5rem;padding:.75rem 1rem;background:var(--surface2);border-radius:var(--radius-sm);font-size:.93rem;line-height:1.6}
.q-reveal.show{display:block}
.reveal-btn{font-size:.82rem;color:var(--accent);cursor:pointer;border:none;background:none;font-weight:600;padding:.2rem 0}
.reveal-btn:hover{text-decoration:underline}

/* ── Stats ── */
.stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:1rem;margin:1.25rem 0}
.stat-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:1.25rem;text-align:center}
.stat-num{font-size:2rem;font-weight:800;color:var(--accent)}
.stat-label{font-size:.85rem;color:var(--text2);margin-top:.25rem}

/* ── Pathway ── */
.pathway{display:flex;flex-direction:column;gap:0;margin:1.25rem 0}
.pathway-step{display:flex;gap:1rem;position:relative}
.pathway-line{display:flex;flex-direction:column;align-items:center;width:24px;flex-shrink:0}
.pathway-dot{width:14px;height:14px;border-radius:50%;background:var(--accent);border:3px solid var(--accent-bg);flex-shrink:0;z-index:1}
.pathway-bar{width:2px;flex:1;background:var(--border)}
.pathway-step:last-child .pathway-bar{display:none}
.pathway-content{padding-bottom:1.5rem}
.pathway-content strong{display:block;margin-bottom:.15rem}

/* ── Badges ── */
.evidence-badge{display:inline-block;padding:.15rem .5rem;border-radius:4px;font-size:.78rem;font-weight:700}
.ev-strong{background:#dcfce7;color:#166534}
.ev-moderate{background:#fef3c7;color:#92400e}
.ev-mixed{background:#e0e7ff;color:#3730a3}
.ev-weak{background:#fee2e2;color:#991b1b}
.grade-pill{display:inline-block;padding:.2rem .6rem;border-radius:20px;font-weight:700;font-size:.82rem}
.grade-a{background:#dcfce7;color:#166534}
.grade-ab{background:#d1fae5;color:#065f46}
.grade-b{background:#fef3c7;color:#92400e}
.grade-d{background:#fee2e2;color:#991b1b}
.grade-f{background:#991b1b;color:#fff}

/* ── Two col ── */
.two-col{display:grid;grid-template-columns:1fr 1fr;gap:1rem;margin:1rem 0}
@media(max-width:600px){.two-col{grid-template-columns:1fr}}

/* ── References ── */
.ref-list{counter-reset:ref}
.ref-list li{counter-increment:ref;font-size:.88rem;color:var(--text2);margin-bottom:.5rem;padding-left:2rem;position:relative;list-style:none}
.ref-list li::before{content:"["counter(ref)"]";position:absolute;left:0;font-weight:600;color:var(--accent)}

/* ── Flashcard panel ── */
.flashcard-panel{position:fixed;inset:0;z-index:200;background:rgba(0,0,0,.6);display:none;align-items:center;justify-content:center;backdrop-filter:blur(4px)}
.flashcard-panel.open{display:flex}
.flashcard-box{background:var(--surface);border-radius:var(--radius);max-width:520px;width:90%;max-height:85vh;overflow:auto;padding:2rem;position:relative}
.flashcard-close{position:absolute;top:.75rem;right:.75rem;width:32px;height:32px;border-radius:50%;border:1px solid var(--border);background:var(--surface);cursor:pointer;font-size:1rem;display:flex;align-items:center;justify-content:center;color:var(--text)}
.flashcard-close:hover{background:var(--red);color:#fff;border-color:var(--red)}
.fc-counter{text-align:center;font-size:.85rem;color:var(--text3);margin-bottom:1rem}
.fc-card{min-height:180px;perspective:800px;cursor:pointer;margin-bottom:1.5rem}
.fc-inner{position:relative;width:100%;min-height:180px;transition:transform .5s;transform-style:preserve-3d}
.fc-card.flipped .fc-inner{transform:rotateY(180deg)}
.fc-front,.fc-back{position:absolute;inset:0;backface-visibility:hidden;border-radius:var(--radius-sm);padding:1.5rem;display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center}
.fc-front{background:linear-gradient(135deg,var(--accent-bg),#e0e7ff);border:2px solid var(--accent)}
.fc-front .fc-term{font-size:1.3rem;font-weight:700;margin-bottom:.5rem}
.fc-front .fc-hint{font-size:.85rem;color:var(--text3);margin-top:auto}
.fc-back{background:linear-gradient(135deg,#dcfce7,#d1fae5);border:2px solid var(--green);transform:rotateY(180deg)}
.fc-back .fc-def{font-size:1.05rem;line-height:1.6}
.fc-nav{display:flex;gap:.75rem;justify-content:center}
.fc-nav button{padding:.5rem 1.2rem;border-radius:var(--radius-sm);border:1px solid var(--border);background:var(--surface);color:var(--text);font-weight:600;cursor:pointer;transition:all .2s}
.fc-nav button:hover{background:var(--accent-bg);border-color:var(--accent)}
.fc-nav button.primary{background:var(--accent);color:#fff;border-color:var(--accent)}
.fc-nav button.primary:hover{background:var(--accent2)}
.fc-chapter-select{display:flex;gap:.4rem;flex-wrap:wrap;justify-content:center;margin-bottom:1.25rem}
.fc-chip{padding:.3rem .7rem;border-radius:20px;font-size:.78rem;font-weight:600;border:1px solid var(--border);background:var(--surface);color:var(--text2);cursor:pointer;transition:all .2s}
.fc-chip:hover,.fc-chip.active{background:var(--accent);color:#fff;border-color:var(--accent)}

/* ── Quiz mode overlay ── */
.quiz-overlay{position:fixed;inset:0;z-index:200;background:var(--bg);display:none;flex-direction:column;overflow:auto}
.quiz-overlay.open{display:flex}
.qo-header{display:flex;align-items:center;justify-content:space-between;padding:.75rem 1.25rem;background:var(--surface);border-bottom:1px solid var(--border);position:sticky;top:0;z-index:1}
.qo-header h3{font-size:1rem;margin:0}
.qo-close{width:32px;height:32px;border-radius:50%;border:1px solid var(--border);background:var(--surface);cursor:pointer;font-size:1rem;display:flex;align-items:center;justify-content:center;color:var(--text)}
.qo-body{flex:1;padding:2rem 1.25rem;max-width:700px;margin:0 auto;width:100%}
.qo-progress{height:6px;background:var(--surface3);border-radius:3px;margin-bottom:1.5rem;overflow:hidden}
.qo-progress-bar{height:100%;background:var(--accent);border-radius:3px;transition:width .3s}
.qo-q-num{font-size:.85rem;color:var(--text3);margin-bottom:.3rem}
.qo-question{font-size:1.15rem;font-weight:700;margin-bottom:1.25rem;line-height:1.5}
.qo-options{display:flex;flex-direction:column;gap:.6rem;margin-bottom:1.5rem}
.qo-opt{padding:.85rem 1rem;border:2px solid var(--border);border-radius:var(--radius-sm);cursor:pointer;font-size:.95rem;transition:all .2s;text-align:left;background:var(--surface)}
.qo-opt:hover{border-color:var(--accent);background:var(--accent-bg)}
.qo-opt.selected{border-color:var(--accent);background:var(--accent-bg)}
.qo-opt.correct{border-color:var(--green);background:#dcfce7}
.qo-opt.wrong{border-color:var(--red);background:#fef2f2}
.qo-opt.disabled{pointer-events:none;opacity:.7}
.qo-explain{display:none;padding:1rem;background:var(--surface2);border-radius:var(--radius-sm);margin-bottom:1.25rem;font-size:.93rem;line-height:1.6}
.qo-explain.show{display:block}
.qo-footer{display:flex;justify-content:space-between;align-items:center;padding-top:.5rem}
.qo-btn{padding:.6rem 1.5rem;border-radius:var(--radius-sm);border:none;font-weight:600;cursor:pointer;font-size:.9rem;transition:all .2s}
.qo-btn.next{background:var(--accent);color:#fff}
.qo-btn.next:hover{background:var(--accent2)}
.qo-btn:disabled{opacity:.4;cursor:not-allowed}
.qo-score-card{text-align:center;padding:3rem 1rem}
.qo-score-num{font-size:4rem;font-weight:800;color:var(--accent)}
.qo-score-label{font-size:1.1rem;color:var(--text2);margin-bottom:1.5rem}
.qo-score-bar{display:flex;gap:.5rem;justify-content:center;margin-bottom:2rem}
.qo-score-dot{width:14px;height:14px;border-radius:50%;border:2px solid var(--border)}
.qo-score-dot.hit{background:var(--green);border-color:var(--green)}
.qo-score-dot.miss{background:var(--red);border-color:var(--red)}

/* ── Progress tracker ── */
.progress-bar-wrap{margin:1rem 0}
.progress-item{display:flex;align-items:center;gap:.75rem;margin-bottom:.5rem}
.progress-item label{font-size:.88rem;font-weight:500;min-width:120px}
.prog-track{flex:1;height:8px;background:var(--surface3);border-radius:4px;overflow:hidden}
.prog-fill{height:100%;background:var(--accent);border-radius:4px;transition:width .4s}
.prog-pct{font-size:.82rem;color:var(--text3);min-width:36px;text-align:right}

/* ── Debate legacy (still used inline) ── */
.debate{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:1.25rem;margin:1.25rem 0}
.debate-title{font-weight:700;font-size:1.05rem;margin-bottom:.75rem;display:flex;align-items:center;gap:.5rem}
.side{padding:.75rem 1rem;border-radius:var(--radius-sm);margin-bottom:.75rem}
.side-a{background:#dcfce7;border-left:3px solid var(--green)}
.side-b{background:#fef2f2;border-left:3px solid var(--red)}
.side-label{font-weight:700;font-size:.85rem;text-transform:uppercase;margin-bottom:.25rem}
.side-a .side-label{color:var(--green)}
.side-b .side-label{color:var(--red)}
.verdict{background:var(--accent-bg);border:1px solid var(--accent);border-radius:var(--radius-sm);padding:.85rem 1rem;margin-top:.5rem}
.verdict-label{font-weight:700;color:var(--accent);font-size:.85rem;margin-bottom:.25rem}

/* ── Footer ── */
footer{padding:2rem 0;text-align:center;color:var(--text3);font-size:.85rem;border-top:1px solid var(--border);margin-top:2rem}

/* ── Back to top ── */
.back-top{position:fixed;bottom:1.5rem;right:1.5rem;width:42px;height:42px;border-radius:50%;background:var(--accent);color:#fff;border:none;cursor:pointer;font-size:1.2rem;display:none;align-items:center;justify-content:center;box-shadow:0 4px 12px rgba(37,99,235,.3);z-index:99;transition:opacity .3s}
.back-top.show{display:flex}

/* ── Adaptive Quiz overlay ── */
.aq-overlay{position:fixed;inset:0;z-index:200;background:var(--bg);display:none;flex-direction:column;overflow:auto}
.aq-overlay.open{display:flex}
.aq-header{display:flex;align-items:center;justify-content:space-between;padding:.75rem 1.25rem;background:var(--surface);border-bottom:1px solid var(--border);position:sticky;top:0;z-index:1}
.aq-header h3{font-size:1rem;margin:0}
.aq-close{width:32px;height:32px;border-radius:50%;border:1px solid var(--border);background:var(--surface);cursor:pointer;font-size:1rem;display:flex;align-items:center;justify-content:center;color:var(--text)}
.aq-body{flex:1;padding:1.5rem 1.25rem;max-width:720px;margin:0 auto;width:100%}
.aq-progress{height:6px;background:var(--surface3);border-radius:3px;margin-bottom:1rem;overflow:hidden}
.aq-progress-bar{height:100%;background:var(--accent);border-radius:3px;transition:width .3s}
.aq-q-num{font-size:.82rem;color:var(--text3);margin-bottom:.2rem}
.aq-diff-badge{display:inline-block;font-size:.7rem;font-weight:700;padding:.15rem .5rem;border-radius:4px;margin-left:.5rem}
.aq-diff-1{background:#dcfce7;color:#166534}
.aq-diff-2{background:#dbeafe;color:#1d4ed8}
.aq-diff-3{background:#fef3c7;color:#92400e}
.aq-diff-4{background:#fee2e2;color:#991b1b}
.aq-question{font-size:1.1rem;font-weight:700;margin-bottom:1.25rem;line-height:1.5}
.aq-streak{display:flex;align-items:center;gap:.5rem;margin-bottom:1rem}
.aq-streak-bar{display:flex;gap:3px}
.aq-streak-dot{width:10px;height:10px;border-radius:50%;background:var(--surface3);transition:background .2s}
.aq-streak-dot.hit{background:var(--green)}
.aq-streak-dot.miss{background:var(--red)}
.aq-streak-label{font-size:.82rem;color:var(--text3)}
.aq-options{display:flex;flex-direction:column;gap:.55rem;margin-bottom:1.25rem}
.aq-opt{padding:.8rem 1rem;border:2px solid var(--border);border-radius:var(--radius-sm);cursor:pointer;font-size:.93rem;transition:all .15s;text-align:left;background:var(--surface);line-height:1.5}
.aq-opt:hover{border-color:var(--accent);background:var(--accent-bg)}
.aq-opt.correct{border-color:var(--green);background:#dcfce7}
.aq-opt.wrong{border-color:var(--red);background:#fef2f2}
.aq-opt.disabled{pointer-events:none;opacity:.7}
.aq-explain{display:none;padding:.85rem 1rem;background:var(--surface2);border-radius:var(--radius-sm);margin-bottom:1rem;font-size:.9rem;line-height:1.6}
.aq-explain.show{display:block}
.aq-footer{display:flex;justify-content:space-between;align-items:center}
.aq-btn{padding:.55rem 1.3rem;border-radius:var(--radius-sm);border:none;font-weight:600;cursor:pointer;font-size:.88rem;transition:all .2s}
.aq-btn.primary{background:var(--accent);color:#fff}
.aq-btn.primary:hover{background:var(--accent2)}
.aq-btn:disabled{opacity:.35;cursor:not-allowed}
.aq-btn.secondary{background:var(--surface2);color:var(--text)}
.aq-btn.secondary:hover{background:var(--surface3)}

/* ── Diagnostic overlay ── */
.diag-overlay{position:fixed;inset:0;z-index:200;background:var(--bg);display:none;flex-direction:column;overflow:auto}
.diag-overlay.open{display:flex}

/* ── Mastery dashboard ── */
.mastery-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:1rem;margin:1.5rem 0}
.mastery-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:1.25rem;position:relative;overflow:hidden}
.mastery-card-top{display:flex;justify-content:space-between;align-items:start;margin-bottom:.75rem}
.mastery-ch{font-size:.75rem;font-weight:700;text-transform:uppercase;color:var(--accent);letter-spacing:.05em}
.mastery-level{font-size:.72rem;font-weight:700;padding:.15rem .5rem;border-radius:12px}
.mastery-level.beginner{background:#fee2e2;color:#991b1b}
.mastery-level.learning{background:#fef3c7;color:#92400e}
.mastery-level.proficient{background:#dbeafe;color:#1d4ed8}
.mastery-level.mastery{background:#dcfce7;color:#166534}
.mastery-title{font-weight:700;font-size:.95rem;margin-bottom:.5rem;line-height:1.3}
.mastery-bar{height:8px;background:var(--surface3);border-radius:4px;overflow:hidden;margin-bottom:.5rem}
.mastery-fill{height:100%;border-radius:4px;transition:width .5s}
.mastery-fill.beginner{background:var(--red)}
.mastery-fill.learning{background:var(--amber)}
.mastery-fill.proficient{background:var(--accent)}
.mastery-fill.mastery{background:var(--green)}
.mastery-stats{display:flex;justify-content:space-between;font-size:.78rem;color:var(--text3)}
.mastery-action{margin-top:.75rem;text-align:center}
.mastery-action button{font-size:.82rem;padding:.4rem .9rem;border-radius:var(--radius-sm);border:1px solid var(--accent);background:var(--accent-bg);color:var(--accent);cursor:pointer;font-weight:600;transition:all .2s}
.mastery-action button:hover{background:var(--accent);color:#fff}

/* ── Recommendation box ── */
.rec-box{background:linear-gradient(135deg,var(--accent-bg),#e0e7ff);border:1px solid var(--accent);border-radius:var(--radius);padding:1.25rem;margin:1.5rem 0}
.rec-title{font-weight:700;margin-bottom:.75rem;display:flex;align-items:center;gap:.5rem}
.rec-items{display:flex;flex-direction:column;gap:.5rem}
.rec-item{display:flex;align-items:center;gap:.75rem;padding:.5rem .75rem;background:var(--surface);border-radius:var(--radius-sm);font-size:.9rem}
.rec-item .rec-chip{font-size:.72rem;font-weight:700;padding:.15rem .5rem;border-radius:4px;background:var(--accent);color:#fff;white-space:nowrap}
.rec-item .rec-action{margin-left:auto;font-size:.8rem;color:var(--accent);cursor:pointer;font-weight:600;white-space:nowrap}
.rec-item .rec-action:hover{text-decoration:underline}

/* ── Diagnostic results ── */
.diag-result{text-align:center;padding:2rem 1rem}
.diag-score-big{font-size:3.5rem;font-weight:800;color:var(--accent)}
.diag-label{font-size:1rem;color:var(--text2);margin-bottom:1.5rem}
.diag-topic-grid{display:grid;grid-template-columns:1fr 1fr;gap:.75rem;text-align:left;margin:1.5rem 0}
@media(max-width:500px){.diag-topic-grid{grid-template-columns:1fr}}
.diag-topic{padding:.75rem;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-sm)}
.diag-topic-name{font-weight:700;font-size:.88rem;margin-bottom:.25rem}
.diag-topic-bar{height:6px;background:var(--surface3);border-radius:3px;overflow:hidden}
.diag-topic-fill{height:100%;border-radius:3px}
.diag-topic-score{font-size:.78rem;color:var(--text3);margin-top:.2rem}

.inline-img{width:100%;max-width:560px;aspect-ratio:16/10;object-fit:cover;border-radius:var(--radius-sm);margin:1rem 0 .25rem;display:block;box-shadow:var(--shadow-sm)}
.acc-body-inner .inline-img{margin-left:auto;margin-right:auto}

/* ── Resources ── */
.resources-section{margin-top:2rem;padding-top:1.5rem;border-top:1px dashed var(--border)}
.resources-title{font-size:1.1rem;font-weight:700;margin-bottom:1rem;display:flex;align-items:center;gap:.5rem}
.video-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:1rem;margin-bottom:1.25rem}
.video-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-sm);overflow:hidden;transition:box-shadow .2s,transform .2s;text-decoration:none;color:var(--text)}
.video-card:hover{box-shadow:var(--shadow);transform:translateY(-2px);text-decoration:none}
.video-thumb{width:100%;aspect-ratio:16/9;object-fit:cover;background:var(--surface2);display:block}
.video-info{padding:.6rem .75rem}
.video-info .vid-title{font-size:.88rem;font-weight:600;line-height:1.4;margin-bottom:.2rem}
.video-info .vid-source{font-size:.75rem;color:var(--text3)}
.photo-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(200px,1fr));gap:.75rem}
.photo-card{border-radius:var(--radius-sm);overflow:hidden;position:relative}
.photo-card img{width:100%;aspect-ratio:4/3;object-fit:cover;display:block;transition:transform .3s}
.photo-card:hover img{transform:scale(1.03)}
.resources-note{font-size:.82rem;color:var(--text3);margin-top:.5rem;font-style:italic}

/* ── Sidebar ── */
.sidebar{position:fixed;top:0;left:0;width:240px;height:100vh;background:var(--surface);border-right:1px solid var(--border);z-index:150;overflow-y:auto;padding:1rem 0;transition:transform .3s}
.sidebar-logo{padding:0 1rem .75rem;font-size:1rem;font-weight:700;color:var(--text);border-bottom:1px solid var(--border);margin-bottom:.5rem}
.sidebar-logo span{color:var(--accent)}
.sidebar-group{margin-bottom:.5rem}
.sidebar-label{font-size:.7rem;font-weight:700;text-transform:uppercase;letter-spacing:.08em;color:var(--text3);padding:.5rem 1rem .25rem}
.sidebar-link{display:block;padding:.4rem 1rem .4rem 1.5rem;font-size:.85rem;color:var(--text2);text-decoration:none;transition:all .15s;border-left:3px solid transparent}
.sidebar-link:hover,.sidebar-link.active{color:var(--accent);background:var(--accent-bg);border-left-color:var(--accent);text-decoration:none}
.sidebar-link.sub{padding-left:2rem;font-size:.8rem}
.sidebar-toggle{display:none;position:fixed;top:.75rem;left:.75rem;z-index:160;width:40px;height:40px;border-radius:var(--radius-sm);border:1px solid var(--border);background:var(--surface);color:var(--text);font-size:1.2rem;cursor:pointer;align-items:center;justify-content:center}
.page-wrapper{margin-left:240px;transition:margin-left .3s}

/* ── Resources Hub ── */
.res-hub-chapter{margin-bottom:2rem;padding-bottom:1.5rem;border-bottom:1px solid var(--border)}
.res-hub-chapter:last-child{border-bottom:none}
.res-hub-chapter h4{margin-bottom:.75rem;display:flex;align-items:center;gap:.5rem}

/* ── Q&A Chat ── */
.chat-panel{max-width:680px;margin:0 auto}
.chat-window{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);overflow:hidden;display:flex;flex-direction:column;height:480px}
.chat-header{padding:.75rem 1rem;background:var(--surface2);border-bottom:1px solid var(--border);font-weight:700;font-size:.95rem;display:flex;align-items:center;gap:.5rem}
.chat-header .status-dot{width:8px;height:8px;border-radius:50%;background:var(--green)}
.chat-messages{flex:1;overflow-y:auto;padding:1rem;display:flex;flex-direction:column;gap:.75rem}
.chat-msg{max-width:85%;padding:.65rem .9rem;border-radius:var(--radius-sm);font-size:.9rem;line-height:1.55;animation:msgIn .3s ease}
.chat-msg.bot{background:var(--accent-bg);color:var(--text);align-self:flex-start;border-bottom-left-radius:2px}
.chat-msg.user{background:var(--accent);color:#2a2000;align-self:flex-end;border-bottom-right-radius:2px}
.chat-msg .msg-label{font-size:.7rem;font-weight:600;color:var(--text3);margin-bottom:.2rem;display:block}
.chat-msg.user .msg-label{color:#3a2c00}
body.dark .chat-msg.user{color:#1a1300 !important;background:linear-gradient(135deg,#E8C87A,#D9B86A) !important;border-color:transparent !important}
body.dark .chat-msg.user .msg-label{color:#241c00}
.chat-suggestions{display:flex;flex-wrap:wrap;gap:.4rem;padding:.5rem 1rem;border-top:1px solid var(--border);background:var(--surface2)}
.chat-sug-btn{padding:.35rem .7rem;border-radius:20px;border:1px solid var(--border);background:var(--surface);color:var(--text2);font-size:.78rem;font-weight:500;cursor:pointer;transition:all .2s;white-space:nowrap}
.chat-sug-btn:hover{background:var(--accent);color:#fff;border-color:var(--accent)}
.chat-input-row{display:flex;gap:.5rem;padding:.75rem 1rem;border-top:1px solid var(--border);background:var(--surface)}
.chat-input{flex:1;padding:.55rem .85rem;border:1px solid var(--border);border-radius:var(--radius-sm);font-size:.9rem;background:var(--bg);color:var(--text);outline:none;transition:border-color .2s}
.chat-input:focus{border-color:var(--accent)}
.chat-input::placeholder{color:var(--text3)}
.chat-send{padding:.55rem 1rem;border-radius:var(--radius-sm);border:none;background:var(--accent);color:#fff;font-weight:600;font-size:.9rem;cursor:pointer;transition:background .2s}
.chat-send:hover{background:var(--accent2)}
.chat-disclaimer{font-size:.75rem;color:var(--text3);text-align:center;padding:.5rem;font-style:italic}
@keyframes msgIn{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}

/* ── Floating AI button & full-screen modal ── */
.ai-fab{position:fixed;bottom:1.5rem;right:1.5rem;z-index:300;width:60px;height:60px;border-radius:50%;border:none;background:linear-gradient(135deg,var(--accent),#7c3aed);color:#fff;font-size:1.5rem;cursor:pointer;box-shadow:0 6px 20px rgba(0,0,0,.25);display:flex;align-items:center;justify-content:center;transition:transform .2s,box-shadow .2s}
.ai-fab:hover{transform:scale(1.08);box-shadow:0 8px 26px rgba(0,0,0,.3)}
.ai-fab .fab-badge{position:absolute;top:0;right:0;width:14px;height:14px;border-radius:50%;background:var(--green);border:2px solid #fff}
.ai-modal{position:fixed;inset:0;z-index:320;background:var(--bg);display:none;flex-direction:column;opacity:0;transition:opacity .25s}
.ai-modal.open{display:flex;opacity:1}
.ai-modal-header{display:flex;align-items:center;gap:.75rem;padding:1rem 1.5rem;background:var(--surface);border-bottom:1px solid var(--border)}
.ai-modal-header .ai-title{font-size:1.05rem;font-weight:700}
.ai-modal-header .ai-sub{font-size:.78rem;color:var(--text3)}
.ai-close{margin-left:auto;width:38px;height:38px;border-radius:50%;border:1px solid var(--border);background:var(--surface);color:var(--text);font-size:1.1rem;cursor:pointer;display:flex;align-items:center;justify-content:center;transition:all .2s}
.ai-close:hover{background:var(--red);color:#fff;border-color:var(--red)}
.ai-modal-body{flex:1;overflow-y:auto;padding:1.25rem 1.5rem;display:flex;flex-direction:column;gap:.75rem}
.ai-modal-body .chat-msg{max-width:75%}
.ai-modal-footer{padding:1rem 1.5rem;background:var(--surface);border-top:1px solid var(--border)}
.ai-suggestions{display:flex;flex-wrap:wrap;gap:.4rem;padding:0 1.5rem .75rem;background:var(--surface)}
.ai-input-row{display:flex;gap:.5rem}
.ai-input{flex:1;padding:.7rem .95rem;border:1px solid var(--border);border-radius:var(--radius-sm);font-size:.95rem;background:var(--bg);color:var(--text);outline:none;transition:border-color .2s}
.ai-input:focus{border-color:var(--accent)}
.ai-input::placeholder{color:var(--text3)}
.ai-send-btn{padding:.7rem 1.3rem;border-radius:var(--radius-sm);border:none;background:var(--accent);color:#fff;font-weight:600;font-size:.95rem;cursor:pointer;transition:background .2s}
.ai-send-btn:hover{background:var(--accent2)}

@media(max-width:600px){
  .hero{padding:2rem 0 1.5rem}
  section{padding:2rem 0 1.5rem}
  .stats{grid-template-columns:1fr 1fr}
  .video-grid{grid-template-columns:1fr}
  .photo-grid{grid-template-columns:1fr 1fr}
  .sidebar{transform:translateX(-100%)}
  .sidebar.open{transform:translateX(0)}
  .sidebar-toggle{display:flex}
  .page-wrapper{margin-left:0}
  .chat-window{height:400px}
}

/* ── Hero (index) ── */
.hero{background:linear-gradient(180deg,var(--accent-bg),var(--bg));border-bottom:1px solid var(--border)}
.hero-badge{display:inline-flex;align-items:center;gap:.4rem;font-size:.75rem;font-weight:700;letter-spacing:.06em;text-transform:uppercase;color:var(--accent);background:var(--surface);border:1px solid var(--border);padding:.35rem .8rem;border-radius:20px;margin-bottom:1rem}
.hero-badge .dot{width:7px;height:7px;border-radius:50%;background:var(--green);display:inline-block}
.hero-actions{display:flex;gap:.75rem;justify-content:center;flex-wrap:wrap;margin-top:1.6rem}

/* ── Table of Contents (index) ── */
.toc-intro{text-align:center;max-width:560px;margin:0 auto 2rem}
.toc-intro h2{font-size:2.6rem;font-weight:800}
.toc-intro .toc-sub{color:var(--text2);font-size:1rem;margin-top:.5rem}
.ch-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:1rem;max-width:920px;margin:0 auto}
.ch-card{position:relative;background:var(--surface);border:1px solid var(--border);border-radius:16px;padding:1.1rem 1.2rem;display:flex;align-items:center;gap:1rem;color:var(--text);text-decoration:none;transition:transform .18s,box-shadow .18s,border-color .18s;overflow:hidden}
.ch-card::before{content:"";position:absolute;left:0;top:0;bottom:0;width:4px;background:var(--accent);opacity:0;transition:opacity .18s}
.ch-card:hover{transform:translateY(-3px);box-shadow:0 10px 26px rgba(0,0,0,.12);border-color:var(--accent);text-decoration:none}
.ch-card:hover::before{opacity:1}
.ch-num{width:46px;height:46px;border-radius:12px;flex-shrink:0;background:linear-gradient(135deg,var(--accent),#7c3aed);color:#fff;font-weight:800;font-size:1.35rem;display:flex;align-items:center;justify-content:center;box-shadow:0 4px 10px rgba(124,58,237,.25)}
.ch-card h4{font-size:1.08rem;font-weight:700;margin:0;line-height:1.25}
.ch-card p{font-size:.82rem;color:var(--text2);margin:.28rem 0 0;line-height:1.4}
.ch-go{display:flex;align-items:center;gap:.2rem;font-size:.8rem;font-weight:700;color:var(--accent);white-space:nowrap;transition:gap .18s}
.ch-card:hover .ch-go{gap:.5rem}
.ch-card-body{flex:1;min-width:0}

/* ══════════════════════════════════════════
   DESIGN POLISH (2026 refresh) — editorial, typography-led
   ══════════════════════════════════════════ */
html{scroll-behavior:smooth}
body{letter-spacing:.01em;-webkit-font-smoothing:antialiased}
::selection{background:var(--accent);color:#fff}

/* Typography scale */
h1,h2,h3{letter-spacing:-.015em;line-height:1.15;font-weight:800;text-wrap:balance}
h2{font-size:clamp(1.7rem,3.4vw,2.4rem)}
h3{letter-spacing:-.01em}
p{text-wrap:pretty}

/* Header */
header{background:color-mix(in srgb,var(--surface) 88%,transparent);backdrop-filter:blur(14px) saturate(160%);box-shadow:var(--shadow-sm)}
.logo{font-size:1.12rem;font-weight:800;letter-spacing:-.01em}
.btn-icon{box-shadow:var(--shadow-sm);transition:transform .18s,box-shadow .18s,background .18s,border-color .18s}
.btn-icon:hover{transform:translateY(-1px);box-shadow:var(--shadow)}

/* Sections + labels */
section{padding:4rem 0 3rem}
.section-label{background:color-mix(in srgb,var(--accent) 12%,var(--surface));color:var(--accent);border:1px solid color-mix(in srgb,var(--accent) 22%,transparent);font-weight:700}

/* Cards — premium resting state */
.stat-card,.mastery-card,.diag-topic,.video-card,.debate,.quiz,.acc-item,.rec-box,.chat-window{
  border-radius:var(--radius);border-color:var(--border);box-shadow:var(--shadow-sm);transition:box-shadow .22s,transform .22s,border-color .22s}
.stat-card:hover,.mastery-card:hover,.video-card:hover{box-shadow:var(--shadow-lg);transform:translateY(-3px)}

/* Buttons */
.qo-btn,.aq-btn,.ai-send-btn,.chat-send,.fc-nav button{box-shadow:var(--shadow-sm);transition:transform .18s,box-shadow .18s,background .18s}
.qo-btn:hover,.aq-btn:hover,.ai-send-btn:hover,.chat-send:hover{transform:translateY(-1px);box-shadow:var(--shadow)}
.qo-btn.next,.aq-btn.primary{background:linear-gradient(135deg,var(--accent),var(--accent2))}

/* Quizzes & accordions */
.quiz{border:2px solid var(--border)}
.acc-header{border-left:2px solid transparent;transition:background .2s,border-color .2s}
.acc-item.open>.acc-header{border-left:2px solid var(--accent)}

/* Q&A / flashcard option pills */
.qo-opt,.aq-opt{transition:border-color .15s,background .15s,transform .12s}
.qo-opt:not(.disabled):hover,.aq-opt:not(.disabled):hover{transform:translateX(3px)}

/* Resources video thumbnails */
.video-thumb{border-radius:var(--radius-sm) var(--radius-sm) 0 0}

/* ------------------------------------------------
   SIDEBAR — refined
   ------------------------------------------------ */
.sidebar-logo{font-weight:800;letter-spacing:-.01em}
.sidebar-label{letter-spacing:.09em}
.sidebar-link{border-left:3px solid transparent;transition:all .15s}
.sidebar-link:hover{transform:translateX(2px)}

/* ------------------------------------------------
   INDEX — Hero (only used on index.html)
   ------------------------------------------------ */
.hero{
  background:
    radial-gradient(1200px 500px at 50% -10%, color-mix(in srgb,var(--accent) 18%,transparent), transparent 60%),
    linear-gradient(180deg,color-mix(in srgb,var(--accent-bg) 70%,var(--bg)),var(--bg));
  border-bottom:1px solid var(--border);
  padding:4.5rem 0 3.5rem;text-align:center}
.hero h1{font-size:clamp(2.1rem,5vw,3.6rem);font-weight:800;letter-spacing:-.025em;max-width:760px;margin:0 auto 1rem}
.hero-badge{font-weight:700;box-shadow:var(--shadow-sm)}
.hero-actions{margin-top:2rem}

/* INDEX — TOC cards (only on index.html) */
.toc-intro h2{font-size:clamp(2rem,4.5vw,3rem)}
.toc-intro .toc-sub{font-size:1.05rem}
.ch-card{border-radius:var(--radius);box-shadow:var(--shadow-sm);border:1px solid var(--border);transition:transform .2s,box-shadow .2s,border-color .2s}
.ch-card:hover{box-shadow:var(--shadow-lg);border-color:color-mix(in srgb,var(--accent) 45%,var(--border))}
.ch-num{box-shadow:0 6px 16px color-mix(in srgb,var(--accent) 35%,transparent)}

/* AI floating button */
.ai-fab{box-shadow:0 10px 28px color-mix(in srgb,var(--accent) 45%,transparent)}

/* Back to top */
.back-top{box-shadow:var(--shadow-lg)}

/* Focus visibility */
:focus-visible{outline:2px solid var(--accent);outline-offset:2px}

/* ── Image Lightbox (click to view + download) ── */
.lb-overlay{position:fixed;inset:0;z-index:400;background:rgba(10,10,14,.92);display:none;align-items:center;justify-content:center;flex-direction:column;padding:2rem;backdrop-filter:blur(4px)}
.lb-overlay.open{display:flex}
.lb-stage{position:relative;max-width:94vw;max-height:84vh;display:flex;align-items:center;justify-content:center}
.lb-img{max-width:94vw;max-height:82vh;object-fit:contain;border-radius:10px;box-shadow:0 20px 60px rgba(0,0,0,.5)}
.lb-bar{position:absolute;top:-2.6rem;right:0;display:flex;gap:.5rem}
.lb-btn{width:38px;height:38px;border-radius:10px;border:1px solid rgba(255,255,255,.25);background:rgba(255,255,255,.12);color:#fff;font-size:1.05rem;cursor:pointer;display:flex;align-items:center;justify-content:center;transition:background .15s}
.lb-btn:hover{background:rgba(255,255,255,.28)}
.lb-btn.dl{width:auto;padding:0 .9rem;gap:.35rem;font-size:.85rem;font-weight:600}
.lb-caption{color:#cfd3e0;margin-top:1rem;font-size:.9rem;text-align:center;max-width:80vw}
.inline-img{cursor:zoom-in}
@media(max-width:600px){.lb-bar{top:-2.3rem}}


/* ── Type system: Avenir Next body + Cormorant Garamond (Claude-style slab-serif) headings ── */
h1,h2,h3,h4,h5,h6{font-family:var(--font-heading);font-weight:500;letter-spacing:-.02em}
.logo{font-family:var(--font-heading);font-weight:600;letter-spacing:-.01em}
.quiz-title,.qo-question,.aq-question,.acc-header,.fc-front .fc-term,.fc-back .fc-def,.stat-num,.mastery-title,.rec-title,.vid-title,.ai-title,.res-hub-chapter{font-family:var(--font-heading);font-weight:500}
/* ══════════════════════════════════════════
   BUILD — Readability & engagement polish (Aug 2026)
   ══════════════════════════════════════════ */

/* Reading progress bar (top of page) */
#readingBar{position:fixed;top:0;left:0;height:4px;width:0;z-index:500;background:linear-gradient(90deg,var(--accent),#7c3aed,#e879f9);transition:width .1s linear;pointer-events:none}

/* Comfortable reading measure + rhythm inside chapter bodies */
.acc-body-inner{line-height:1.85}
.acc-body-inner p{max-width:68ch}
.inline-img{width:100%;border-radius:var(--radius);border:1px solid var(--border2);box-shadow:var(--shadow);margin:.9rem 0 .2rem}
img.inline-img + img.inline-img{width:calc(50% - .5rem);display:inline-block;margin:0 0 .2rem .5rem;vertical-align:top}

/* Tables — modern card look + hover + mobile horizontal scroll */
.table-wrap{overflow-x:auto;-webkit-overflow-scrolling:touch;border-radius:var(--radius);border:1px solid var(--border);box-shadow:var(--shadow-sm);margin:.4rem 0 .4rem}
.table-wrap table{margin:0;border:none}
.table-wrap th,.table-wrap td{padding:.7rem .95rem;vertical-align:top}
.table-wrap th{background:var(--surface2);font-weight:700;position:sticky;top:0}
.table-wrap tr:hover td{background:color-mix(in srgb,var(--accent) 6%,var(--surface))}
@media(max-width:600px){.table-wrap th,.table-wrap td{padding:.55rem .7rem;font-size:.86rem}}

/* Debate boxes — colour-coded sides */
.tab-panel{padding:1.1rem 1.3rem}
.tab-panel.active{animation:fadeUp .25s ease}
.tab-panel.side-a-tab{background:color-mix(in srgb,var(--green) 7%,var(--surface));border-left:4px solid var(--green)}
.tab-panel.side-b-tab{background:color-mix(in srgb,var(--red) 6%,var(--surface));border-left:4px solid var(--red)}
.tab-panel.verdict-tab{background:color-mix(in srgb,var(--amber) 8%,var(--surface));border-top:2px dashed color-mix(in srgb,var(--amber) 45%,transparent)}
.tab-nav .tab-btn:nth-child(1).active{color:var(--green);border-bottom-color:var(--green);background:color-mix(in srgb,var(--green) 10%,transparent)}
.tab-nav .tab-btn:nth-child(2).active{color:var(--red);border-bottom-color:var(--red);background:color-mix(in srgb,var(--red) 8%,transparent)}
.tab-nav .tab-btn:nth-child(3).active{color:var(--amber);border-bottom-color:var(--amber);background:color-mix(in srgb,var(--amber) 10%,transparent)}
@keyframes fadeUp{from{opacity:0;transform:translateY(4px)}to{opacity:1;transform:translateY(0)}}

/* Key-takeaway callout */
.callout{margin:1.5rem 0;border-radius:var(--radius);border:1px solid var(--border2);background:linear-gradient(180deg,color-mix(in srgb,var(--accent-bg) 65%,var(--surface)),var(--surface));border-left:5px solid var(--accent);padding:1.15rem 1.3rem;box-shadow:var(--shadow-sm)}
.callout h4{font-family:var(--font);font-size:1rem;font-weight:800;margin-bottom:.55rem;display:flex;align-items:center;gap:.5rem;letter-spacing:0}
.callout h4 .co-ico{width:26px;height:26px;border-radius:8px;background:var(--accent);color:#fff;display:inline-flex;align-items:center;justify-content:center;font-size:.85rem;flex:none}
.callout ul{margin:0;padding-left:1.15rem}
.callout li{margin:.28rem 0;font-size:.93rem;line-height:1.7}
.callout .callout-note{margin-top:.65rem;padding-top:.6rem;border-top:1px dashed var(--border2);font-size:.85rem;color:var(--text2);font-style:italic}

/* Email capture (launch notifications) */
.capture{border-radius:var(--radius);border:1px solid var(--border2);background:var(--surface);padding:1.4rem 1.5rem;box-shadow:var(--shadow);text-align:center}
.capture h3{margin-bottom:.4rem;font-size:1.25rem}
.capture p{font-size:.9rem;color:var(--text2);max-width:52ch;margin:0 auto .9rem}
.capture-form{display:flex;gap:.5rem;max-width:460px;margin:0 auto}
.capture-input{flex:1;min-width:0;padding:.7rem .95rem;border:1px solid var(--border);border-radius:var(--radius-sm);font-size:.95rem;background:var(--bg);color:var(--text);outline:none;transition:border-color .2s}
.capture-input:focus{border-color:var(--accent)}
.capture-btn{flex:none;padding:.7rem 1.3rem;border-radius:var(--radius-sm);border:none;background:linear-gradient(135deg,var(--accent),var(--accent2));color:#fff;font-weight:700;cursor:pointer;font-size:.95rem;transition:transform .18s,box-shadow .18s}
.capture-btn:hover{transform:translateY(-1px);box-shadow:var(--shadow)}
.capture-msg{margin-top:.7rem;font-size:.86rem;color:var(--green);min-height:1.2em}
.capture-note{margin-top:.55rem;font-size:.75rem;color:var(--text3)}
@media(max-width:520px){.capture-form{flex-direction:column}}

/* Trust strip + author card + feature grid (homepage) */
.trust-strip{display:flex;flex-wrap:wrap;gap:.6rem;justify-content:center;margin:1.6rem 0 0}
.trust-chip{display:inline-flex;align-items:center;gap:.45rem;font-size:.8rem;font-weight:600;color:var(--text2);background:var(--surface);border:1px solid var(--border);border-radius:20px;padding:.4rem .9rem;box-shadow:var(--shadow-sm)}
.author-card{display:flex;gap:1.1rem;align-items:flex-start;max-width:720px;border-radius:var(--radius);border:1px solid var(--border);background:var(--surface);padding:1.4rem;box-shadow:var(--shadow-sm)}
.author-ava{flex:none;width:64px;height:64px;border-radius:50%;background:linear-gradient(135deg,var(--accent),#7c3aed);color:#fff;display:flex;align-items:center;justify-content:center;font-weight:800;font-size:1.4rem}
.feature-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(230px,1fr));gap:.9rem;margin-top:1.2rem}
.feature-card{border-radius:var(--radius);border:1px solid var(--border);background:var(--surface);padding:1.15rem 1.2rem;box-shadow:var(--shadow-sm);transition:box-shadow .2s,transform .2s}
.feature-card:hover{box-shadow:var(--shadow-lg);transform:translateY(-3px)}
.feature-card .co-ico{width:34px;height:34px;border-radius:10px;background:var(--accent-bg);color:var(--accent);display:flex;align-items:center;justify-content:center;font-size:1rem;margin-bottom:.55rem}
.feature-card h4{font-family:var(--font);font-weight:800;font-size:1rem;margin-bottom:.3rem}
.feature-card p{font-size:.86rem;color:var(--text2);line-height:1.6}

/* Exam prep & certificate (exam.html) */
.std-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(215px,1fr));gap:.8rem;margin-top:1.2rem}
.study-step{display:flex;align-items:center;gap:.8rem;border-radius:var(--radius);border:1px solid var(--border);background:var(--surface);padding:.85rem 1rem;box-shadow:var(--shadow-sm)}
.step-num{flex:none;width:34px;height:34px;border-radius:50%;background:var(--accent-bg);color:var(--accent);font-weight:800;display:flex;align-items:center;justify-content:center}
.study-step.done .step-num{background:var(--green);color:#fff}
.step-info{flex:1;min-width:0}
.step-info h4{font-family:var(--font);font-size:.95rem;font-weight:700;margin:0}
.step-info span{font-size:.78rem;color:var(--text3)}
.step-status{flex:none;font-size:.76rem;font-weight:700;padding:.28rem .6rem;border-radius:20px}
.step-status.rs{background:var(--accent-bg);color:var(--accent)}
.step-status.done{background:color-mix(in srgb,var(--green) 15%,transparent);color:var(--green)}
.exam-panel{border-radius:var(--radius);border:1px solid var(--border);background:var(--surface);box-shadow:var(--shadow);padding:1.4rem}
.exam-meta{display:flex;gap:1rem;flex-wrap:wrap;align-items:center;margin-bottom:1rem}
.ekey{display:inline-flex;flex-direction:column;align-items:center;padding:.7rem 1.1rem;border:1px solid var(--border);border-radius:var(--radius-sm);background:var(--bg);min-width:86px}
.ekey b{font-size:1.3rem;color:var(--accent)}
.ekey span{font-size:.72rem;color:var(--text3);text-transform:uppercase;letter-spacing:.06em}
.exam-q{padding:1rem 0;border-bottom:1px solid var(--border)}
.exam-q:last-of-type{border-bottom:none}
.exam-opt{display:block;width:100%;text-align:left;margin:.4rem 0;padding:.7rem .95rem;border:1px solid var(--border2);border-radius:var(--radius-sm);background:var(--bg);color:var(--text);font-size:.93rem;cursor:pointer;transition:all .15s}
.exam-opt:hover{border-color:var(--accent);background:var(--accent-bg)}
.exam-opt.correct{background:color-mix(in srgb,var(--green) 15%,var(--surface));border-color:var(--green)}
.exam-opt.wrong{background:color-mix(in srgb,var(--red) 12%,var(--surface));border-color:var(--red)}
.exam-opt:disabled{cursor:not-allowed;opacity:.85}
.exam-explain{margin:.6rem 0 .4rem;padding:.75rem .9rem;border-radius:var(--radius-sm);background:color-mix(in srgb,var(--accent) 6%,var(--surface));border:1px dashed var(--border2);font-size:.86rem;line-height:1.65}
.exam-verdict{margin-top:1rem;padding:.9rem 1.1rem;border-radius:var(--radius);font-weight:700;text-align:center}
.exam-verdict.good{background:color-mix(in srgb,var(--green) 15%,var(--surface));border:1px solid var(--green);color:var(--green)}
.exam-verdict.mid{background:color-mix(in srgb,var(--amber) 15%,var(--surface));border:1px solid var(--amber);color:var(--amber)}
.exam-verdict.low{background:color-mix(in srgb,var(--red) 12%,var(--surface));border:1px solid var(--red);color:var(--red)}
.cert-gate{border-radius:var(--radius);border:1px dashed var(--border2);background:color-mix(in srgb,var(--accent-bg) 40%,var(--surface));padding:1rem 1.2rem;margin-bottom:1rem}
.cert-check{display:flex;gap:.6rem;align-items:center;padding:.3rem 0;font-size:.9rem}
.cert-check .ok{color:var(--green);font-weight:700}
.cert-check .no{color:var(--text3)}
.cert-actions{display:flex;gap:.6rem;align-items:center;flex-wrap:wrap;margin-top:.8rem}
.cert-flash{font-size:.85rem;color:var(--green);font-weight:600;min-height:1.2em}

/* Certificate canvas holder */
.cert-view{display:none;position:fixed;inset:0;z-index:400;background:rgba(10,10,14,.9);align-items:center;justify-content:center;padding:1.5rem;backdrop-filter:blur(4px)}
.cert-view.open{display:flex}
.cert-view canvas{max-width:92vw;max-height:80vh;box-shadow:0 24px 70px rgba(0,0,0,.5);border-radius:8px;background:#fff}
.onthis .sidebar-link{font-size:.8rem}

/* ═══════ FLASHCARD UI REDESIGN ═══════ */
.flashcard-box{max-width:560px;padding:2.2rem 2rem}
.fc-chapter-select{margin-bottom:1.4rem}
.fc-chip{padding:.35rem .8rem;font-size:.78rem;border-radius:999px;background:var(--surface);color:var(--text2);border:1px solid var(--border2);box-shadow:var(--shadow-sm)}
.fc-chip:hover{border-color:var(--accent);color:var(--accent);transform:translateY(-1px);box-shadow:var(--shadow)}
.fc-chip.active{background:linear-gradient(135deg,var(--accent),#7c3aed);color:#fff;border-color:transparent;box-shadow:var(--shadow)}
.fc-counter{font-size:.82rem;color:var(--text3);margin-bottom:1.1rem;font-weight:700;letter-spacing:.02em}
.fc-card{min-height:230px;perspective:1000px;margin-bottom:1.6rem}
.fc-inner{min-height:230px}
.fc-front,.fc-back{border-radius:20px;padding:2rem 1.6rem;box-shadow:0 18px 34px rgba(79,70,229,.16),0 4px 10px rgba(15,23,42,.06)}
.fc-front{background:linear-gradient(135deg,#4f46e5 0%,#7c3aed 60%,#9333ea 100%);border:none;overflow:hidden;position:relative}
.fc-front:before{content:"🃏";position:absolute;font-size:7rem;opacity:.10;right:-1rem;bottom:-1.6rem;transform:rotate(-12deg)}
.fc-front .fc-term{font-size:1.45rem;font-weight:800;color:#fff;line-height:1.35;text-shadow:0 2px 8px rgba(0,0,0,.15)}
.fc-front .fc-hint{color:rgba(255,255,255,.82);background:rgba(255,255,255,.16);border:1px solid rgba(255,255,255,.28);padding:.3rem .85rem;border-radius:999px;font-size:.78rem;margin-top:1.2rem;backdrop-filter:blur(2px)}
.fc-back{background:var(--surface);border:2px solid #c7d2fe}
.fc-back .fc-def{font-size:1.1rem;line-height:1.65;color:var(--text);padding:0 .4rem}
.fc-back .fc-def strong{display:inline-block;background:var(--accent-bg);color:var(--accent);padding:.18rem .6rem;border-radius:999px;font-size:.74rem;margin-bottom:.7rem}
.fc-nav{gap:.8rem;align-items:center}
.fc-nav button{padding:.55rem 1.4rem;border-radius:999px;font-weight:700;border:1px solid var(--border2);background:var(--surface);color:var(--text);box-shadow:var(--shadow-sm)}
.fc-nav button:hover{border-color:var(--accent);color:var(--accent);transform:translateY(-1px);box-shadow:var(--shadow)}
.fc-nav button.primary{background:linear-gradient(135deg,var(--accent),#7c3aed);color:#fff;border:none}
.fc-nav button.primary:hover{filter:brightness(1.05);color:#fff}
.fc-nav button.fc-shuf{margin-left:.2rem;font-size:.82rem}
.fc-progress{display:flex;gap:4px;justify-content:center;margin:0 0 .2rem}
.fc-progress span{width:22px;height:4px;border-radius:2px;background:var(--surface3);transition:background .2s}
.fc-progress span.on{background:var(--accent)}

/* ── Dark theme palette overrides: night dark blue + gold ── */
body.dark .hero h1 span{background:linear-gradient(135deg,#E8C87A,#BFA181);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}
body.dark .ai-fab{background:linear-gradient(135deg,#E8C87A,#D9B24F)}
body.dark #readingBar{background:linear-gradient(90deg,#E8C87A,#F1DCA0,#BFA181)}
body.dark .author-ava{background:linear-gradient(135deg,#E8C87A,#BFA181)}
body.dark .test-prep{border-left-color:#BFA181;background:linear-gradient(180deg,color-mix(in srgb,#BFA181 12%,var(--surface)),var(--surface))}
body.dark .test-prep .tp-tag{background:#BFA181;color:#0A1828}
body.dark .fc-chip.active,body.dark .fc-nav button.primary{background:linear-gradient(135deg,#E8C87A,#BFA181);color:#0A1828}
body.dark .fc-front{background:linear-gradient(135deg,#0F2238 0%,#14304A 60%,#1A3D5C 100%);color:#F1E9D0}


/* ── Light theme palette overrides: blue + gold (echoes dark) ── */
body:not(.dark) .hero h1 span{background:linear-gradient(135deg,#A9741E,#B8860B);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}
body:not(.dark) .ai-fab{background:linear-gradient(135deg,#B8860B,#A9741E)}
body:not(.dark) #readingBar{background:linear-gradient(90deg,#B8860B,#A9741E,#B8860B)}
body:not(.dark) .author-ava{background:linear-gradient(135deg,#B8860B,#A9741E)}
body:not(.dark) .test-prep{border-left-color:#B8860B;background:linear-gradient(180deg,color-mix(in srgb,#B8860B 8%,var(--surface)),var(--surface))}
body:not(.dark) .test-prep .tp-tag{background:#B8860B;color:#fff}
body:not(.dark) .fc-chip.active,body:not(.dark) .fc-nav button.primary{background:linear-gradient(135deg,#B8860B,#A9741E);color:#fff}
body:not(.dark) .fc-front{background:linear-gradient(135deg,#EAF1F6 0%,#F1F6F9 60%,#FFFFFF 100%);color:#0A1828}


/* ── Dark-mode refinement: calm buttons + gold→cream heading gradient ── */
body.dark .qo-btn.next,body.dark .aq-btn.primary,body.dark .fc-nav button.primary,
body.dark .fc-chip.active,body.dark .ai-send-btn,body.dark .chat-send,body.dark .chat-msg.user,
body.dark .back-top,body.dark .guide-tab.on,body.dark .rec-item .rec-chip,body.dark .ch-nav .qo-btn,
body.dark .author-ava,body.dark .callout h4 .co-ico,body.dark .guide-chip:hover{
  background:linear-gradient(135deg,#B8860B,#A9741E) !important;color:#F1E9D0 !important;border-color:transparent !important}
body.dark .qo-btn.next:hover,body.dark .aq-btn.primary:hover,body.dark .ai-send-btn:hover,
body.dark .chat-send:hover,body.dark .fc-nav button.primary:hover,body.dark .guide-tab.on:hover{
  background:linear-gradient(135deg,#A9741E,#8E620A) !important}
body.dark h1,body.dark h2,body.dark h3{
  background:linear-gradient(120deg,#E8C87A,#F1E9D0) !important;-webkit-background-clip:text !important;-webkit-text-fill-color:transparent !important;background-clip:text !important}

/* ═══ DARK MODE: pastel & light accent boxes (site-wide) ═══
   The hardcoded pastel callouts/chips/options on every page don't use --surface,
   so they stayed light in night mode. Convert each pastel to a dark-tinted
   background with hue-matched light text. */
body.dark .q-data,body.dark .ev-moderate,body.dark .grade-b,body.dark .mastery-level.learning,body.dark .aq-diff-3,body.dark .adm-chip.frozen{background:#3a2f0e;color:#f7d794}
body.dark .q-flaw,body.dark .q-debate{background:#331520;color:#f9a8d4}
body.dark .q-explain,body.dark .q-application{background:#0c2a1a;color:#86efac}
body.dark .q-calculate,body.dark .q-pyramid{background:#2f2a0c;color:#fde047}
body.dark .q-plan{background:#201438;color:#c4b5fd}
body.dark .q-career{background:#2f1f0d;color:#fdba74}
body.dark .ev-weak,body.dark .grade-d,body.dark .mastery-level.beginner,body.dark .aq-diff-4,body.dark .acct-msg.err,body.dark .adm-msg.err,body.dark .adm-chip.deleted,body.dark .btn.danger{background:#3a1414;color:#fca5a5}
body.dark .qo-opt.wrong,body.dark .aq-opt.wrong,body.dark .side-b{background:#3a1414;color:#fca5a5}
body.dark .ev-strong,body.dark .grade-a,body.dark .mastery-level.mastery,body.dark .aq-diff-1,body.dark .acct-msg.ok,body.dark .adm-msg.ok,body.dark .adm-chip.ok{background:#0c2a1a;color:#86efac}
body.dark .qo-opt.correct,body.dark .aq-opt.correct,body.dark .side-a{background:#0c2a1a;color:#86efac}
body.dark .fc-back{background:linear-gradient(135deg,#0c2a1a,#102d20);color:#86efac}
body.dark .acct-level{background:linear-gradient(135deg,#3a2f0e,#40341a);border-color:#6b5b1a;color:#fdea9a}
body.dark .acct-level .lvl-next{color:#f7d794}
body.dark .acct-bar{background:#6b5b1a}
body.dark .acct-switch .sl:before{background:#f1e9d0}
body.dark .cnq-label select{background:var(--surface);color:var(--text);border-color:var(--border2);color-scheme:dark}
body.dark .cnq-label select option{background:var(--surface);color:var(--text)}
body.dark .soc-ico{background:var(--surface2);color:var(--text)}
body.dark .adm-frozen .adm-stat{background:#3a2f0e;border-color:#6b5b1a}
body.dark .adm-frozen .adm-stat .v{color:#f7d794}
body.dark .aq-diff-2,body.dark .mastery-level.proficient,body.dark .q-mechanism{background:#182a4a;color:#93c5fd}
body.dark .q-transfer{background:#0c2a26;color:#5eead4}
body.dark .adm-tbl .btn.green{background:#0c2a1a;color:#86efac;border-color:#1f7a4d}

/* ═══ FONT STACK — self-hosted (Beijing-proof): Bodoni Moda SC (heads) · Pinyon Script (logo, Bickham-proxy) · EB Garamond (body, Sabon-proxy) · Cinzel (buttons) · Playfair italic (subheads) ═══
   All families live in fonts/ + fonts.css — zero external requests, no Google
   CDN, no VPN needed. CJK falls through to system Songti/SimSun. */
.logo{font-family:var(--font-script);font-weight:400;letter-spacing:0}
.sidebar-logo{font-family:var(--font-script);font-weight:400;letter-spacing:0;font-size:1.12rem}
button,.btn,.btn-login,.qo-btn,.aq-btn,.ai-send-btn,.chat-send{font-family:var(--font-caps);letter-spacing:.06em}
.landing .hero p,.hero p,.section-label{font-family:var(--font-subhead);font-style:italic;letter-spacing:.01em}

/* ═══════════════════════════════════════════════════════════════════════════
   Sidebar — Linear-style rail
   Quiet by default: muted labels, subtle rounded hover pills, tiny uppercase
   section heads, no accent bars. Emphasis is reserved for the active row.

   Collapsing keys on .collapsed, which sidebar JS adds — never on a class
   being absent. With no JS every group stays open, so the nav can't vanish.
   ═══════════════════════════════════════════════════════════════════════════ */

.sidebar{
  width:224px;padding:.5rem 0 2rem;overscroll-behavior:contain;
  background:var(--surface);border-right:1px solid var(--border)}
.page-wrapper{margin-left:224px}

/* ---- wordmark row ---- */
.sidebar-logo{
  display:flex;align-items:center;gap:.5rem;
  padding:.35rem .75rem .6rem;margin-bottom:.35rem;
  font-size:.95rem;border-bottom:1px solid var(--border)}
.sidebar-logo .logo-text{white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.sb-mark{flex:none;width:20px;height:20px;border-radius:5px;margin-right:.45rem;display:block}
.sb-compact-btn{
  flex:none;width:24px;height:24px;display:flex;align-items:center;justify-content:center;
  border:1px solid transparent;border-radius:6px;background:transparent;
  color:var(--text3);font-size:.78rem;line-height:1;cursor:pointer;
  transition:background .14s,color .14s}
.sb-compact-btn:hover{background:var(--surface2);color:var(--text)}
.sb-compact-btn:focus-visible{outline:2px solid var(--accent);outline-offset:1px}

/* ---- group header ---- */
.sidebar-group.part{margin:0 .4rem .1rem}
.part-toggle{
  width:100%;display:flex;align-items:center;gap:.5rem;
  padding:.34rem .5rem;border:0;border-radius:6px;
  background:transparent;color:var(--text2);font:inherit;
  font-size:.795rem;font-weight:600;letter-spacing:-.005em;
  text-align:left;cursor:pointer;transition:background .14s,color .14s}
.part-toggle:hover{background:var(--surface2);color:var(--text)}
.part-toggle:focus-visible{outline:2px solid var(--accent);outline-offset:-1px}
.part-icon{flex:none;width:17px;text-align:center;font-size:.87rem;line-height:1;opacity:.85}
.part-name{flex:1;min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.part-caret{
  flex:none;font-size:.6rem;color:var(--text3);opacity:0;
  transition:transform .16s ease,opacity .14s ease}
.sidebar-group.part:hover .part-caret,
.part-toggle:focus-visible .part-caret{opacity:.8}

/* ---- group body: OPEN by default, only .collapsed closes it ---- */
.part-body{padding:.05rem 0 .3rem}
.sidebar-group.part.collapsed > .part-body{display:none}
.sidebar-group.part.collapsed > .part-toggle .part-caret{transform:rotate(-90deg);opacity:.8}

/* ---- rows ---- */
.sidebar-link{
  display:block;position:relative;
  margin:1px .4rem;padding:.32rem .5rem .32rem 1.85rem;
  border-left:0;border-radius:6px;
  font-size:.795rem;font-weight:500;line-height:1.35;
  color:var(--text2);text-decoration:none;
  white-space:nowrap;overflow:hidden;text-overflow:ellipsis;
  transition:background .14s,color .14s}
.sidebar-link:hover{
  background:var(--surface2);color:var(--text);
  border-left:0;transform:none;text-decoration:none}
.sidebar-link.active{
  background:var(--surface3);color:var(--text);font-weight:650;
  border-left:0}
.sidebar-link.active::before{
  content:"";position:absolute;left:.72rem;top:50%;transform:translateY(-50%);
  width:3px;height:3px;border-radius:50%;background:var(--accent)}
.sidebar-link.sub{padding-left:2.35rem;font-size:.775rem}
.sidebar-link:focus-visible{outline:2px solid var(--accent);outline-offset:-2px}

.sidebar-label{
  padding:.6rem .9rem .2rem 1.15rem;
  font-size:.635rem;font-weight:700;text-transform:uppercase;letter-spacing:.075em;
  color:var(--text3)}

/* ═══ Hover rail ═══
   The sidebar rests as a 56px icon rail and expands when you point at it.
   No toggle button: hovering IS the interaction. Expanding overlays the page
   rather than reflowing it, so content never shifts under the cursor.

   Gated on (hover:hover): a touch device has no hover to expand with, so it
   keeps the full sidebar. Below 901px the sidebar is a drawer already. */
@media (hover:hover) and (min-width:901px){
  .sidebar{width:56px}
  .page-wrapper{margin-left:56px}

  .sidebar .logo-text,
  .sidebar .part-name,
  .sidebar .part-caret,
  .sidebar .part-body{display:none}
  .sidebar .sidebar-logo{justify-content:center;padding-left:0;padding-right:0}
  .sidebar .sb-mark{margin-right:0}
  .part-toggle{justify-content:center;padding:.42rem .3rem}
  .part-icon{width:auto;font-size:1.02rem;opacity:1}

  /* pointed at, or holding keyboard focus -> full rail, floating over content */
  .sidebar:hover,
  .sidebar:focus-within{width:224px;box-shadow:var(--shadow-lg);z-index:200}
  .sidebar:hover .logo-text,
  .sidebar:focus-within .logo-text,
  .sidebar:hover .part-name,
  .sidebar:focus-within .part-name,
  .sidebar:hover .part-caret,
  .sidebar:focus-within .part-caret{display:block}
  .sidebar:hover .sidebar-group.part:not(.collapsed) > .part-body,
  .sidebar:focus-within .sidebar-group.part:not(.collapsed) > .part-body{display:block}
  .sidebar:hover .sidebar-logo,
  .sidebar:focus-within .sidebar-logo{justify-content:flex-start;padding:.35rem .75rem .6rem}
  .sidebar:hover .sb-mark,
  .sidebar:focus-within .sb-mark{margin-right:.45rem}
  .sidebar:hover .part-toggle,
  .sidebar:focus-within .part-toggle{justify-content:flex-start;padding:.34rem .5rem}
  .sidebar:hover .part-icon,
  .sidebar:focus-within .part-icon{width:17px;font-size:.87rem;opacity:.85}
}

/* The old toggle is retired — hovering replaced it. */
.sb-compact-btn{display:none!important}

.sidebar{transition:transform .3s,width .14s cubic-bezier(.16,1,.3,1),box-shadow .14s ease}
.page-wrapper{transition:margin-left .14s cubic-bezier(.16,1,.3,1)}
@media (prefers-reduced-motion:reduce){
  .sidebar,.page-wrapper,.part-caret,.sidebar-link{transition:none}
}

/* Phones: drawer, never a rail. The hover rail above is already gated on
   (hover:hover) and (min-width:901px), so nothing to undo here. */
@media(max-width:900px){
  .page-wrapper{margin-left:0}
}

/* ─── ne-badge-chip: KEY/要点 marker on the deep-revision knowledge
   chapters (Ch3-13 of guide.html). No skins styled it, so it rendered as
   bare unstyled text. Match this skin's gold accent pill language. */
.ne-badge-chip{
  display:inline-block;vertical-align:.12em;
  font-family:var(--font-caps,var(--font));
  font-size:.7rem;font-weight:700;text-transform:uppercase;
  letter-spacing:.07em;line-height:1.5;
  color:var(--accent);background:var(--accent-bg);
  border:1px solid color-mix(in srgb,var(--accent) 35%,transparent);
  border-radius:999px;padding:.13rem .6rem;margin-right:.45rem;
}
body.lang-zh .ne-badge-chip{letter-spacing:.03em}
/* ne-acc-body is only an extra wrapper on the notes body; keep content clean. */
.ne-acc-body .facts,.ne-acc-body ul,.ne-acc-body p{max-width:100%}