/* CrackAnalytics — study-notebook theme: paper, ink, teal, highlighter yellow */
:root{
  --paper:#F7F8F4;
  --card:#FFFFFF;
  --ink:#101820;
  --slate:#5B6470;
  --teal:#0B5D52;
  --teal-soft:#E3F0ED;
  --mark:#FFD84D;
  --mark-soft:#FFF3C4;
  --line:#E4E6E0;
  --easy:#1D7A46;  --easy-bg:#E3F3E9;
  --med:#9A6A00;   --med-bg:#FBF0D2;
  --hard:#B0362C;  --hard-bg:#FBE4E1;
  --radius:12px;
  --font-display:"Bricolage Grotesque",system-ui,sans-serif;
  --font-body:"Inter",system-ui,sans-serif;
  --font-mono:"JetBrains Mono",ui-monospace,monospace;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{background:var(--paper);color:var(--ink);font-family:var(--font-body);font-size:16px;line-height:1.7}
img{max-width:100%}
a{color:var(--teal)}

/* highlighter signature */
.hl{background:linear-gradient(180deg,transparent 55%,var(--mark) 55%,var(--mark) 92%,transparent 92%);padding:0 3px}

/* ---------- header ---------- */
header.site{position:sticky;top:0;z-index:50;background:rgba(247,248,244,.92);backdrop-filter:blur(8px);border-bottom:1px solid var(--line)}
.nav-wrap{max-width:1120px;margin:0 auto;padding:14px 20px;display:flex;align-items:center;gap:20px;flex-wrap:wrap}
.brand{font-family:var(--font-display);font-weight:700;font-size:22px;color:var(--ink);text-decoration:none;letter-spacing:-.02em}
.brand b{color:var(--teal)}
nav.tabs{display:flex;gap:4px;flex-wrap:wrap;margin-left:auto}
nav.tabs a{font-size:13.5px;font-weight:500;color:var(--slate);text-decoration:none;padding:7px 11px;border-radius:8px;white-space:nowrap}
nav.tabs a:hover{background:var(--teal-soft);color:var(--teal)}
nav.tabs a.active{background:var(--ink);color:#fff}
.menu-btn{display:none;margin-left:auto;background:none;border:1px solid var(--line);border-radius:8px;padding:7px 12px;font-size:14px;cursor:pointer;font-family:var(--font-body)}

/* ---------- layout ---------- */
.wrap{max-width:1120px;margin:0 auto;padding:36px 20px 80px}
.grid{display:grid;grid-template-columns:minmax(0,1fr) 300px;gap:40px;align-items:start}
main{min-width:0}

/* ---------- hero ---------- */
.eyebrow{font-size:12.5px;font-weight:600;letter-spacing:.14em;text-transform:uppercase;color:var(--teal);margin-bottom:14px}
h1.hero{font-family:var(--font-display);font-weight:700;font-size:clamp(34px,5.2vw,54px);line-height:1.08;letter-spacing:-.03em;margin-bottom:18px}
.lede{font-size:18px;color:var(--slate);max-width:56ch;margin-bottom:28px}
.hero-cta{display:flex;gap:12px;flex-wrap:wrap;margin-bottom:14px}
.btn{display:inline-block;text-decoration:none;font-weight:600;font-size:15px;padding:12px 22px;border-radius:10px;border:1.5px solid var(--ink)}
.btn.solid{background:var(--ink);color:#fff}
.btn.solid:hover{background:var(--teal);border-color:var(--teal)}
.btn.ghost{color:var(--ink);background:transparent}
.btn.ghost:hover{background:var(--mark-soft)}
.tl-layout{display:grid;grid-template-columns:240px 1fr;gap:36px;align-items:start}
.tl-toc{position:sticky;top:24px;background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:16px 18px;max-height:calc(100vh - 48px);overflow-y:auto}
.tl-toc-title{font-family:var(--font-display);font-weight:700;font-size:14px;text-transform:uppercase;letter-spacing:.04em;color:var(--slate);margin-bottom:10px}
.tl-toc-link{display:block;font-size:14px;color:var(--ink);text-decoration:none;padding:6px 0;border-bottom:1px solid var(--line);line-height:1.35}
.tl-toc-link:last-child{border-bottom:none}
.tl-toc-link:hover{color:var(--teal)}
.tl-toc-link.active{color:var(--teal);font-weight:600}
.tl-content{min-width:0}
@media (max-width: 900px){
  .tl-layout{grid-template-columns:1fr}
  .tl-toc{position:static;max-height:none}
}
.btn.btn-orange{background:var(--teal-soft);border-color:var(--teal);color:var(--teal)}
.btn.btn-orange:hover{background:var(--teal);border-color:var(--teal);color:#fff}
.btn.btn-skyblue{background:var(--teal);border-color:var(--teal);color:#fff}
.btn.btn-skyblue:hover{background:var(--ink);border-color:var(--ink);color:#fff}

/* ---------- topic cards ---------- */
.section-label{font-family:var(--font-display);font-weight:600;font-size:22px;margin:44px 0 18px;letter-spacing:-.01em}
.cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(230px,1fr));gap:14px}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:20px;text-decoration:none;color:var(--ink);display:flex;flex-direction:column;gap:8px;transition:transform .15s,border-color .15s}
.card:hover{transform:translateY(-3px);border-color:var(--teal)}
.card .num{font-family:var(--font-mono);font-size:12px;color:var(--slate)}
.card h3{font-family:var(--font-display);font-size:17.5px;font-weight:600;line-height:1.3}
.card p{font-size:13.5px;color:var(--slate);line-height:1.55}
.card .count{margin-top:auto;font-size:12.5px;font-weight:600;color:var(--teal)}

/* ---------- sticky-note visitor counter (signature) ---------- */
aside.rail{position:sticky;top:84px;display:flex;flex-direction:column;gap:18px}
.sticky-note{background:var(--mark);border-radius:4px;padding:22px 20px 26px;transform:rotate(-1.6deg);box-shadow:0 10px 24px rgba(16,24,32,.14);position:relative}
.sticky-note:before{content:"";position:absolute;top:-10px;left:50%;transform:translateX(-50%) rotate(2deg);width:92px;height:22px;background:rgba(255,255,255,.55);border-left:1px dashed rgba(0,0,0,.08);border-right:1px dashed rgba(0,0,0,.08)}
.sticky-note .label{font-size:12px;font-weight:600;letter-spacing:.12em;text-transform:uppercase;color:#6B5600;margin-bottom:4px}
.sticky-note .big{font-family:var(--font-display);font-weight:700;font-size:44px;line-height:1;color:#3F3200;letter-spacing:-.02em}
.sticky-note .sub{font-size:13px;color:#6B5600;margin-top:6px}

.rail-card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:20px}
.rail-card h4{font-family:var(--font-display);font-size:15.5px;font-weight:600;margin-bottom:12px}
.rail-card a.link{display:flex;align-items:center;gap:8px;font-size:14px;text-decoration:none;color:var(--ink);padding:8px 10px;border-radius:8px}
.rail-card a.link:hover{background:var(--teal-soft);color:var(--teal)}
.rail-card a.link span.ic{width:26px;height:26px;border-radius:6px;background:var(--teal-soft);color:var(--teal);display:flex;align-items:center;justify-content:center;font-size:12px;font-weight:700}
.rail-card a.link span.ic-img{background:none;padding:0;overflow:hidden}
.rail-card a.link span.ic-img img{width:100%;height:100%;object-fit:cover;border-radius:6px;display:block}

/* ---------- topic page ---------- */
.page-head{margin-bottom:30px}
.page-head h1{font-family:var(--font-display);font-weight:700;font-size:clamp(28px,4vw,40px);letter-spacing:-.02em;line-height:1.15;margin-bottom:10px}
.page-head p{color:var(--slate);max-width:62ch}
.meta-row{display:flex;gap:10px;flex-wrap:wrap;margin-top:14px}
.chip{font-size:12.5px;font-weight:600;padding:5px 12px;border-radius:999px;background:var(--teal-soft);color:var(--teal);text-decoration:none}
.chip:hover{background:var(--teal);color:#fff}

/* Q&A accordions */
details.qa{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);margin-bottom:10px;overflow:hidden}
details.qa[open]{border-color:var(--teal)}
details.qa summary{cursor:pointer;list-style:none;display:flex;align-items:flex-start;gap:12px;padding:16px 18px;font-weight:600;font-size:15.5px;line-height:1.45}
details.qa summary::-webkit-details-marker{display:none}
details.qa summary:after{content:"+";margin-left:auto;font-family:var(--font-mono);font-size:18px;color:var(--slate);flex-shrink:0}
details.qa[open] summary:after{content:"−";color:var(--teal)}
.qa-body{padding:0 18px 18px;color:#2A333D;font-size:15px}
.qa-body p{margin-bottom:10px}
.qa-body ul,.qa-body ol{margin:0 0 12px 20px}
.qa-body li{margin-bottom:6px}
.qa-body strong{color:var(--ink)}
.badge{flex-shrink:0;font-size:11px;font-weight:700;letter-spacing:.04em;padding:3px 9px;border-radius:999px;margin-top:2px}
.badge.easy{background:var(--easy-bg);color:var(--easy)}
.badge.med{background:var(--med-bg);color:var(--med)}
.badge.hard{background:var(--hard-bg);color:var(--hard)}

/* code blocks */
pre{position:relative;background:#101820;color:#E8ECEF;border-radius:10px;padding:16px;font-family:var(--font-mono);font-size:13px;line-height:1.6;overflow-x:auto;margin:10px 0 14px}
pre code{font-family:inherit}
.copy-btn{position:absolute;top:8px;right:8px;background:#2A333D;color:#C9D2DA;border:none;border-radius:6px;font-size:11.5px;font-family:var(--font-body);font-weight:600;padding:5px 10px;cursor:pointer}
.copy-btn:hover{background:var(--teal);color:#fff}
code.inline{font-family:var(--font-mono);font-size:.88em;background:var(--mark-soft);padding:1px 6px;border-radius:5px}

/* tables */
table.cmp{width:100%;border-collapse:collapse;font-size:14px;margin:10px 0 14px;background:var(--card)}
table.cmp th,table.cmp td{border:1px solid var(--line);padding:10px 12px;text-align:left;vertical-align:top}
table.cmp th{background:var(--teal-soft);color:var(--teal);font-weight:600}

/* resource list */
.res{display:flex;align-items:center;gap:14px;background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:14px 16px;margin-bottom:10px;text-decoration:none;color:var(--ink)}
.res:hover{border-color:var(--teal)}
.res .ficon{width:38px;height:38px;border-radius:8px;background:var(--hard-bg);color:var(--hard);display:flex;align-items:center;justify-content:center;font-size:11px;font-weight:700;flex-shrink:0}
.res .ficon.ppt{background:var(--med-bg);color:var(--med)}
.res .t{font-weight:600;font-size:14.5px;line-height:1.35}
.res .s{font-size:12.5px;color:var(--slate)}
.res .dl{margin-left:auto;font-size:13px;font-weight:600;color:var(--teal);white-space:nowrap}

/* callout */
.note{background:var(--mark-soft);border-left:4px solid var(--mark);border-radius:0 10px 10px 0;padding:14px 16px;font-size:14.5px;margin:18px 0}

/* footer */
footer.site{border-top:1px solid var(--line);background:var(--card)}
.foot-wrap{max-width:1120px;margin:0 auto;padding:34px 20px;display:flex;gap:24px;flex-wrap:wrap;align-items:center;justify-content:space-between;font-size:14px;color:var(--slate)}
.foot-wrap a{color:var(--teal);text-decoration:none;margin-right:16px}
.foot-wrap a:hover{text-decoration:underline}

/* responsive */
@media (max-width:960px){
  .grid{grid-template-columns:1fr}
  aside.rail{position:static;order:-1;flex-direction:row;flex-wrap:wrap}
  .sticky-note{flex:1;min-width:220px}
  .rail-card{flex:1;min-width:220px}
}
@media (max-width:760px){
  nav.tabs{display:none;width:100%}
  nav.tabs.open{display:flex;flex-direction:column}
  nav.tabs.open a{padding:11px 12px;font-size:15px}
  .menu-btn{display:block}
}
:focus-visible{outline:2.5px solid var(--teal);outline-offset:2px}
@media (prefers-reduced-motion:reduce){*{transition:none!important;scroll-behavior:auto}}

/* ---------- single-page tab sections ---------- */
.tab-section{display:none}
.tab-section.active{display:block;animation:fadein .25s ease}
@keyframes fadein{from{opacity:0;transform:translateY(6px)}to{opacity:1;transform:none}}

/* practice question banks */
ol.qbank{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:18px 18px 18px 40px;font-size:14.5px}
ol.qbank li{margin-bottom:10px;line-height:1.55}
ol.qbank li em{color:var(--slate);font-size:13px}


/* ---------- author name line ---------- */
.eyebrow-name{font-size:14px;color:var(--slate);margin:-6px 0 14px}
.eyebrow-name strong{color:var(--teal)}

/* ---------- company buttons ---------- */
.co-btns{display:flex;flex-wrap:wrap;gap:10px;margin-bottom:24px}
.co-btn{font-family:var(--font-body);font-size:14px;font-weight:600;padding:10px 16px;border-radius:999px;border:1.5px solid var(--line);background:var(--card);color:var(--ink);cursor:pointer;transition:all .15s}
.co-btn:hover{border-color:var(--teal);color:var(--teal)}
.co-btn.active{background:var(--ink);color:#fff;border-color:var(--ink)}
.co-panel{display:none}
.co-panel.active{display:block;animation:fadein .25s ease}

/* ---------- pdf reader overlay ---------- */
.view-btn{border:none;background:var(--teal-soft);color:var(--teal);font-family:var(--font-body);font-weight:600;font-size:13px;padding:8px 14px;border-radius:8px;cursor:pointer;margin-left:auto;white-space:nowrap}
.view-btn:hover{background:var(--teal);color:#fff}
.pdf-overlay{display:none;position:fixed;inset:0;background:rgba(16,24,32,.75);z-index:100;padding:2vh 2vw}
.pdf-overlay.open{display:flex;align-items:center;justify-content:center}
.pdf-box{background:var(--paper);border-radius:14px;width:min(960px,100%);height:94vh;display:flex;flex-direction:column;overflow:hidden;box-shadow:0 30px 80px rgba(0,0,0,.4)}
.pdf-bar{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:12px 18px;border-bottom:1px solid var(--line);font-weight:600;font-size:14.5px}
.pdf-close{border:none;background:var(--hard-bg);color:var(--hard);font-weight:700;font-family:var(--font-body);font-size:13px;padding:7px 14px;border-radius:8px;cursor:pointer}
.pdf-close:hover{background:var(--hard);color:#fff}
#pdf-frame{flex:1;width:100%;border:none;background:#525659}


/* ================= COURSE MODE ================= */
body.course{margin:0}
.layout{display:flex;min-height:100vh}

/* --- sidebar --- */
#sidebar{width:300px;min-width:300px;position:fixed;top:0;left:0;bottom:0;overflow-y:auto;background:var(--ink);color:#EAECEF;z-index:50;display:flex;flex-direction:column}
.sb-brand{padding:20px 20px 12px}
.sb-brand a{font-family:var(--font-head);font-size:22px;color:#fff;text-decoration:none}
.sb-brand b{color:var(--marker, #FFD84D);color:#FFD84D}
.sb-by{font-size:12px;color:#9AA3AE;margin-top:2px}
.sb-progress{padding:0 20px 14px;border-bottom:1px solid rgba(255,255,255,.08)}
.sb-bar{height:8px;background:rgba(255,255,255,.12);border-radius:99px;overflow:hidden}
#sb-fill{height:100%;width:0;background:linear-gradient(90deg,#17B097,#FFD84D);border-radius:99px;transition:width .4s ease}
.sb-pct{font-size:12px;color:#9AA3AE;margin-top:6px}
.sb-nav{flex:1;padding:8px 10px 20px}
.sb-sec{margin-bottom:2px}
.sb-sec-btn{width:100%;display:flex;align-items:center;gap:9px;background:none;border:none;color:#EAECEF;font-family:var(--font-body);font-size:14px;font-weight:600;padding:11px 10px;border-radius:8px;cursor:pointer;text-align:left}
.sb-sec-btn:hover{background:rgba(255,255,255,.07)}
.sb-sec-btn .ic{font-size:15px}
.sb-sec-btn .n{margin-left:auto;font-size:11px;font-weight:600;background:rgba(255,255,255,.12);padding:2px 8px;border-radius:99px;color:#C3C9D1}
.sb-sec-btn .ar{font-size:11px;color:#9AA3AE;transition:transform .2s}
.sb-sec.open .sb-sec-btn .ar{transform:rotate(180deg)}
.sb-lessons{display:none;padding:2px 0 6px}
.sb-sec.open .sb-lessons{display:block}
.sb-lesson{display:flex;align-items:center;gap:9px;padding:8px 10px 8px 16px;margin:1px 4px;color:#B9C0C9;font-size:13.5px;text-decoration:none;border-radius:7px;line-height:1.35}
.sb-lesson:hover{background:rgba(255,255,255,.07);color:#fff}
.sb-lesson.active{background:rgba(23,176,151,.18);color:#fff}
.sb-lesson .ck{width:16px;height:16px;min-width:16px;border:1.6px solid #5B6470;border-radius:50%;display:inline-flex;align-items:center;justify-content:center;font-size:10px}
.sb-lesson.done .ck{background:#17B097;border-color:#17B097;color:#0e1417}
.sb-lesson.done .ck::after{content:"✓";font-weight:800}
.sb-lesson.done .lt{color:#7fd6c6}
.sb-foot{padding:14px 20px;border-top:1px solid rgba(255,255,255,.08);display:flex;gap:14px;flex-wrap:wrap}
.sb-foot a{color:#9AA3AE;font-size:12.5px;text-decoration:none}
.sb-foot a:hover{color:#fff}
.sb-foot-link{display:inline-flex;align-items:center;gap:5px}
.sb-foot-link img{width:16px;height:16px;object-fit:cover;border-radius:4px}

/* --- content --- */
#content{margin-left:300px;flex:1;padding:34px 44px 60px}
.lesson{display:none;animation:fadein .25s ease}
.lesson.active{display:block}
.l-crumb{font-size:12.5px;font-weight:600;letter-spacing:.06em;text-transform:uppercase;color:var(--teal);margin-bottom:10px}
.lesson .wrap{padding:0}
.lesson-foot{margin-top:34px;padding-top:20px;border-top:1.5px dashed var(--line);display:flex;align-items:center;justify-content:space-between;gap:14px;flex-wrap:wrap}
.complete{display:flex;align-items:center;gap:9px;font-size:14.5px;font-weight:600;color:var(--slate);cursor:pointer}
.complete input{width:18px;height:18px;accent-color:var(--teal);cursor:pointer}
.pn{display:flex;gap:10px}
.pn-btn{font-family:var(--font-body);font-size:14px;font-weight:600;padding:10px 18px;border-radius:10px;border:1.5px solid var(--line);background:var(--card);color:var(--ink);cursor:pointer}
.pn-btn:hover{border-color:var(--teal);color:var(--teal)}
.pn-btn.next{background:var(--ink);color:#fff;border-color:var(--ink)}
.pn-btn.next:hover{background:var(--teal);border-color:var(--teal);color:#fff}
.course-foot{margin-top:40px;background:none;border-top:1px solid var(--line);padding:18px 0 0;color:var(--slate);font-size:13.5px}

/* --- mobile topbar --- */
.topbar{display:none;position:sticky;top:0;z-index:60;background:var(--ink);color:#fff;padding:12px 16px;align-items:center;gap:14px}
.topbar .menu-btn{background:rgba(255,255,255,.12);border:none;color:#fff;font-family:var(--font-body);font-weight:600;font-size:14px;padding:8px 14px;border-radius:8px;cursor:pointer}
.tb-brand{font-family:var(--font-head);font-size:19px}
.tb-brand b{color:#FFD84D}

@media (max-width: 900px){
  .topbar{display:flex}
  #sidebar{transform:translateX(-100%);transition:transform .25s ease;width:290px}
  #sidebar.open{transform:translateX(0);box-shadow:0 0 60px rgba(0,0,0,.5)}
  #content{margin-left:0;padding:22px 16px 50px}
}

/* --- author photo --- */
.sb-brand{display:flex;align-items:center;gap:12px}
.sb-avatar{width:46px;height:46px;border-radius:50%;object-fit:cover;border:2px solid #17B097}
.rail-avatar{width:74px;height:74px;border-radius:50%;object-fit:cover;border:3px solid var(--teal);display:block;margin:0 auto 10px}

/* --- centered lessons (fix right-side gap) --- */
.lesson{max-width:1010px;margin-left:auto;margin-right:auto}
.course-foot{max-width:1010px;margin-left:auto;margin-right:auto}
.lesson .wrap{max-width:100%}

/* --- resume section --- */
.resume-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:14px;margin:6px 0 10px}
.rcard{background:var(--card);border:1.5px solid var(--line);border-radius:12px;padding:16px 18px}
.rcard h4{font-family:var(--font-head);font-size:16px;margin:0 0 8px}
.rcard ul{margin:0;padding-left:18px}
.rcard li{font-size:14px;line-height:1.55;margin-bottom:5px}
.resume-sample{display:flex;gap:24px;align-items:flex-start;flex-wrap:wrap;background:var(--card);border:1.5px solid var(--line);border-radius:14px;padding:20px}
.resume-img{width:280px;max-width:100%;border:1px solid var(--line);border-radius:8px;box-shadow:0 10px 30px rgba(16,24,32,.12)}
.resume-sample>div{flex:1;min-width:250px}
.gh-btn{display:inline-block;background:var(--ink);color:#fff;font-weight:600;font-size:14.5px;padding:12px 20px;border-radius:10px;text-decoration:none;margin-top:6px}
.gh-btn:hover{background:var(--teal)}
.chip.gh{background:var(--ink);color:#fff;border-color:var(--ink)}
.tool-list li{margin-bottom:9px;font-size:14.5px;line-height:1.55}

/* --- answer images --- */
.qa-img{max-width:100%;height:auto;border:1px solid var(--line);border-radius:10px;margin:10px 0;display:block;background:#fff}
.qa-img-wrap{text-align:center;margin:18px 0}
.qa-img-wrap .qa-img{margin:0 auto;display:inline-block}

/* --- Aptitude Test module --- */
.apt-root{margin-top:10px}

/* category menu */
.apt-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:14px}
.apt-card{display:flex;align-items:center;gap:14px;text-align:left;background:var(--card);border:1.5px solid var(--line);border-radius:var(--radius);padding:18px;cursor:pointer;font-family:var(--font-body)}
.apt-card:hover{border-color:var(--teal);background:var(--teal-soft)}
.apt-card-ic{font-size:26px;flex:0 0 auto}
.apt-card-body{display:flex;flex-direction:column;gap:4px;flex:1;min-width:0}
.apt-card-title{font-weight:700;color:var(--ink);font-size:15px}
.apt-card-meta{font-size:13px;color:var(--slate)}
.apt-card-arrow{font-size:18px;color:var(--teal);flex:0 0 auto}

/* quiz view */
.apt-quiz{max-width:720px}
.apt-quiz-top{display:flex;align-items:center;justify-content:space-between;margin-bottom:14px}
.apt-back{background:none;border:none;color:var(--teal);font-weight:600;font-size:14px;cursor:pointer;padding:4px 0}
.apt-back:hover{text-decoration:underline}
.apt-quiz-section{font-size:13px;font-weight:600;color:var(--slate);background:var(--teal-soft);padding:5px 12px;border-radius:20px}
.apt-progress-row{margin-bottom:22px}
.apt-progress-label{display:block;font-size:13px;color:var(--slate);margin-bottom:6px;font-weight:600}
.apt-progress-bar{width:100%;height:8px;background:var(--line);border-radius:6px;overflow:hidden}
.apt-progress-fill{height:100%;background:var(--teal);border-radius:6px;transition:width .3s ease}
.apt-question{font-family:var(--font-display);font-weight:700;font-size:19px;line-height:1.4;color:var(--ink);margin-bottom:20px}
.apt-options{display:flex;flex-direction:column;gap:10px;margin-bottom:18px}
.apt-option{display:flex;align-items:center;gap:12px;text-align:left;width:100%;background:var(--card);border:1.5px solid var(--line);border-radius:10px;padding:13px 16px;cursor:pointer;font-family:var(--font-body);font-size:14.5px;color:var(--ink)}
.apt-option:hover:not(:disabled){border-color:var(--teal)}
.apt-option:disabled{cursor:default}
.apt-opt-radio{flex:0 0 auto;width:18px;height:18px;border-radius:50%;border:2px solid var(--line);display:inline-block}
.apt-option.apt-selected{border-color:var(--teal);background:var(--teal-soft)}
.apt-option.apt-selected .apt-opt-radio{border-color:var(--teal);background:var(--teal)}
.apt-option.apt-correct{border-color:var(--easy);background:var(--easy-bg)}
.apt-option.apt-correct .apt-opt-radio{border-color:var(--easy);background:var(--easy)}
.apt-option.apt-wrong{border-color:var(--hard);background:var(--hard-bg)}
.apt-option.apt-wrong .apt-opt-radio{border-color:var(--hard);background:var(--hard)}
.apt-explain{background:var(--mark-soft);border:1px solid #EBD98A;border-radius:10px;padding:14px 16px;font-size:14px;line-height:1.55;color:#4A3F0A;margin-bottom:18px}
.apt-explain strong{color:var(--ink)}
.apt-actions{display:flex;gap:12px}

/* summary view */
.apt-summary{max-width:600px}
.apt-summary-section{font-size:13px;font-weight:600;color:var(--slate);background:var(--teal-soft);padding:5px 12px;border-radius:20px;display:inline-block;margin-bottom:20px}
.apt-score-ring{width:120px;height:120px;border-radius:50%;border:10px solid var(--teal);display:flex;align-items:center;justify-content:center;margin:0 auto 24px}
.apt-score-pct{font-family:var(--font-display);font-weight:700;font-size:28px;color:var(--ink)}
.apt-score-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;margin-bottom:24px}
.apt-score-box{background:var(--card);border:1.5px solid var(--line);border-radius:10px;padding:16px 8px;text-align:center;display:flex;flex-direction:column;gap:4px}
.apt-score-num{font-family:var(--font-display);font-weight:700;font-size:24px;color:var(--ink)}
.apt-score-lbl{font-size:12.5px;color:var(--slate);font-weight:600;text-transform:uppercase;letter-spacing:.03em}
.apt-score-box.apt-score-good .apt-score-num{color:var(--easy)}
.apt-score-box.apt-score-bad .apt-score-num{color:var(--hard)}
.apt-hist{background:var(--card);border:1.5px solid var(--line);border-radius:10px;padding:14px 16px;margin-bottom:24px}
.apt-hist-title{font-weight:700;font-size:13px;color:var(--slate);margin-bottom:10px;text-transform:uppercase;letter-spacing:.03em}
.apt-hist-row{display:flex;justify-content:space-between;font-size:13.5px;color:var(--ink);padding:6px 0;border-top:1px solid var(--line)}
.apt-hist-row:first-of-type{border-top:none}
.apt-summary-actions{flex-wrap:wrap}

@media (max-width:640px){
  .apt-grid{grid-template-columns:1fr}
  .apt-score-grid{grid-template-columns:1fr 1fr 1fr}
}

/* ================= SITE SEARCH ================= */
.sb-search{position:relative;padding:14px 20px 16px;border-bottom:1px solid rgba(255,255,255,.08)}
.sb-search-ic{position:absolute;left:32px;top:23px;font-size:13px;opacity:.6;pointer-events:none}
.sb-search-input{width:100%;background:rgba(255,255,255,.08);border:1.5px solid rgba(255,255,255,.12);color:#fff;font-family:var(--font-body);font-size:13.5px;border-radius:9px;padding:9px 30px 9px 32px;outline:none;transition:border-color .15s,background .15s}
.sb-search-input::placeholder{color:#8790A0}
.sb-search-input:focus{border-color:#17B097;background:rgba(255,255,255,.12)}
.sb-search-clear{position:absolute;right:26px;top:20px;background:none;border:none;color:#9AA3AE;font-size:13px;cursor:pointer;padding:4px}
.sb-search-clear:hover{color:#fff}
.sb-search-results{position:absolute;left:20px;right:20px;top:100%;margin-top:6px;background:var(--card);border:1px solid var(--line);border-radius:10px;box-shadow:0 20px 50px rgba(0,0,0,.35);max-height:70vh;overflow-y:auto;z-index:200;display:none}
.sb-search-results.open{display:block}
.sr-item{display:block;width:100%;text-align:left;background:none;border:none;border-bottom:1px solid var(--line);padding:11px 14px;cursor:pointer;font-family:var(--font-body)}
.sr-item:last-child{border-bottom:none}
.sr-item:hover{background:var(--teal-soft)}
.sr-item-top{display:flex;align-items:center;gap:8px;margin-bottom:3px}
.sr-sec{font-size:10.5px;font-weight:700;text-transform:uppercase;letter-spacing:.04em;color:var(--teal)}
.sr-q{font-size:13.5px;font-weight:600;color:var(--ink);line-height:1.4}
.sr-snippet{font-size:12px;color:var(--slate);line-height:1.4;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.sr-empty{padding:18px 14px;font-size:13px;color:var(--slate);text-align:center}
.sr-count{padding:9px 14px;font-size:11px;font-weight:600;text-transform:uppercase;letter-spacing:.04em;color:var(--slate);background:var(--paper);border-bottom:1px solid var(--line)}
.qa-flash{animation:qaflash 1.8s ease}
@keyframes qaflash{0%{box-shadow:0 0 0 3px var(--mark)}100%{box-shadow:0 0 0 0 rgba(255,216,77,0)}}

/* ================= SIA CHATBOT ================= */
.sia-toggle{position:fixed;right:22px;bottom:22px;z-index:150;display:flex;align-items:center;gap:8px;background:var(--teal);color:#fff;border:none;border-radius:999px;padding:13px 18px 13px 14px;font-family:var(--font-body);font-weight:700;font-size:14.5px;cursor:pointer;box-shadow:0 12px 30px rgba(11,93,82,.4);transition:transform .15s}
.sia-toggle:hover{transform:translateY(-2px)}
.sia-toggle-icon{width:26px;height:26px;object-fit:contain;flex-shrink:0}
.sia-panel{position:fixed;right:22px;bottom:90px;z-index:150;width:360px;max-width:calc(100vw - 32px);height:min(520px,70vh);background:var(--paper);border:1px solid var(--line);border-radius:16px;box-shadow:0 30px 80px rgba(0,0,0,.35);display:none;flex-direction:column;overflow:hidden}
.sia-panel.open{display:flex}
.sia-head{display:flex;align-items:center;justify-content:space-between;background:var(--ink);color:#fff;padding:14px 16px}
.sia-head-info{display:flex;align-items:center;gap:10px}
.sia-avatar{width:38px;height:38px;object-fit:contain;background:rgba(255,255,255,.12);border-radius:50%;padding:4px;flex-shrink:0}
.sia-name{font-family:var(--font-display);font-weight:700;font-size:15px}
.sia-sub{font-size:11.5px;color:#9AA3AE}
.sia-close{background:none;border:none;color:#9AA3AE;font-size:15px;cursor:pointer;padding:4px}
.sia-close:hover{color:#fff}
.sia-messages{flex:1;overflow-y:auto;padding:16px;display:flex;flex-direction:column;gap:12px;background:var(--paper)}
.sia-msg{max-width:88%;padding:10px 13px;border-radius:13px;font-size:13.5px;line-height:1.55}
.sia-msg p{margin-bottom:6px}
.sia-msg p:last-child{margin-bottom:0}
.sia-msg ul{margin:0 0 8px 18px}
.sia-msg ul:last-child{margin-bottom:0}
.sia-msg li{margin-bottom:4px}
.sia-msg strong{color:var(--ink)}
.sia-msg.bot{align-self:flex-start;background:var(--card);border:1px solid var(--line);color:var(--ink);border-bottom-left-radius:4px}
.sia-msg.user{align-self:flex-end;background:var(--teal);color:#fff;border-bottom-right-radius:4px}
.sia-msg-label{font-size:10.5px;font-weight:700;text-transform:uppercase;letter-spacing:.04em;color:var(--teal);margin-bottom:4px}
.sia-msg.user .sia-msg-label{display:none}
.sia-chip-row{display:flex;flex-wrap:wrap;gap:6px;margin-top:8px}
.sia-chip{background:var(--teal-soft);color:var(--teal);border:none;border-radius:999px;padding:6px 11px;font-size:12px;font-weight:600;cursor:pointer;text-align:left}
.sia-chip:hover{background:var(--teal);color:#fff}
.sia-link-btn{display:inline-block;margin-top:8px;background:var(--ink);color:#fff;text-decoration:none;font-size:12px;font-weight:700;padding:7px 12px;border-radius:8px;cursor:pointer;border:none}
.sia-link-btn:hover{background:var(--teal)}
.sia-input-row{display:flex;gap:8px;padding:12px;border-top:1px solid var(--line);background:var(--card)}
.sia-input{flex:1;border:1.5px solid var(--line);border-radius:9px;padding:10px 12px;font-family:var(--font-body);font-size:13.5px;outline:none}
.sia-input:focus{border-color:var(--teal)}
.sia-send{background:var(--teal);color:#fff;border:none;border-radius:9px;width:40px;font-size:15px;cursor:pointer}
.sia-send:hover{background:var(--ink)}
.sia-typing span{display:inline-block;width:6px;height:6px;background:var(--slate);border-radius:50%;margin-right:3px;animation:siablink 1.2s infinite}
.sia-typing span:nth-child(2){animation-delay:.2s}
.sia-typing span:nth-child(3){animation-delay:.4s}
@keyframes siablink{0%,60%,100%{opacity:.3}30%{opacity:1}}

@media (max-width:640px){
  .sia-toggle-label{display:none}
  .sia-toggle{padding:14px;border-radius:50%}
  .sia-panel{right:12px;left:12px;width:auto;bottom:80px}
}