/* Resources page: 3D shelf and sections */
.visually-hidden{position:absolute!important;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
.res-hero{padding-bottom:40px}

.shelf-sec{padding:0 16px 40px}
.shelf{position:relative;max-width:1320px;margin:0 auto;height:620px;border-radius:32px;overflow:hidden;
  background:radial-gradient(120% 80% at 50% 100%,#E6ECF8 0%,#F4F6FB 45%,#FBFBFD 100%);
  border:1px solid #E3E8F2;touch-action:pan-y;user-select:none;-webkit-user-select:none;cursor:grab;outline:none}
.shelf:focus-visible{box-shadow:0 0 0 3px var(--blue)}
.shelf.dragging{cursor:grabbing}
.sh-head{position:absolute;top:38px;left:0;right:0;text-align:center;z-index:5;pointer-events:none;transition:opacity .45s ease,transform .45s ease}
.shelf.reading .sh-head{opacity:0;transform:translateY(-10px)}
.sh-series{font-size:.78rem;font-weight:600;letter-spacing:.22em;text-transform:uppercase;color:var(--blue)}
.sh-title{font-size:clamp(1.6rem,3vw,2.3rem);font-weight:700;letter-spacing:-.03em;color:var(--navy);margin-top:4px}
.sh-hint{font-size:.85rem;color:var(--gray);margin-top:6px}
.sh-scene{position:absolute;inset:0;perspective:var(--persp,3000px);perspective-origin:50% 40%}
.sh-floor{position:absolute;left:0;right:0;bottom:0;height:118px;background:linear-gradient(#DCE3F1,#E9EEF8);border-top:1px solid #CFD8EA}
.sh-floor::before{content:"";position:absolute;left:50%;top:-14px;width:340px;height:28px;transform:translateX(-50%);border-radius:50%;background:radial-gradient(closest-side,rgba(16,37,74,.28),rgba(16,37,74,0));filter:blur(2px)}
.sh-track{position:absolute;left:50%;bottom:112px;transform-style:preserve-3d}
.sh-wrap{position:absolute;bottom:0;left:0;transform-style:preserve-3d;will-change:transform;cursor:pointer}
.sh-flip{position:absolute;bottom:0;left:0;transform-style:preserve-3d;will-change:transform}
.sh-book{position:relative;transform-style:preserve-3d;transform-origin:left center}
.sh-face{position:absolute;backface-visibility:hidden;-webkit-backface-visibility:hidden;overflow:hidden}
.sh-front,.sh-back{top:0;left:0;height:100%;background:#fff;border-radius:2px 5px 5px 2px;box-shadow:0 20px 40px -18px rgba(16,37,74,.45)}
.sh-back{border-radius:5px 2px 2px 5px}
.sh-front img,.sh-back img{width:100%;height:100%;object-fit:cover;pointer-events:none}
.sh-gloss{position:absolute;inset:0;pointer-events:none;background:linear-gradient(to right,rgba(0,0,0,.14) 0,rgba(255,255,255,.18) 2.5%,rgba(255,255,255,0) 9%,rgba(0,0,0,0) 92%,rgba(0,0,0,.08) 100%)}
.sh-gloss.r{transform:scaleX(-1)}
.sh-backart{width:100%;height:100%;display:flex;flex-direction:column;justify-content:center;gap:14px;padding:28px}
.sh-backart img{width:62%;height:auto;object-fit:contain}
.sh-backart strong{font-size:1.5rem;letter-spacing:-.03em;line-height:1.05}
.sh-backart span{font-size:.85rem;line-height:1.4;opacity:.85}
.sh-backart em{font-style:normal;font-size:.62rem;letter-spacing:.2em;text-transform:uppercase;margin-top:auto;opacity:.8}
.sh-spine{top:0;height:100%;transform:rotateY(-90deg);display:flex;flex-direction:column;align-items:center;justify-content:space-between;padding:14px 0 12px;
  box-shadow:inset 5px 0 10px rgba(255,255,255,.22),inset -6px 0 12px rgba(0,0,0,.3);border-right:1px solid rgba(0,0,0,.1)}
.sh-band{width:100%;height:10px;flex:none}
.sh-stext{flex:1;min-height:0;width:100%;display:flex;align-items:center;justify-content:center;overflow:hidden;padding:6px 0}
.sh-line{writing-mode:vertical-rl;text-orientation:mixed;display:inline-flex;align-items:center;gap:.7em;white-space:nowrap;text-transform:uppercase;line-height:1;font-size:13px}
.sh-line b{font-weight:700;letter-spacing:.08em}
.sh-line i{width:.3em;height:.3em;border-radius:50%;background:currentColor;opacity:.55;flex:none}
.sh-line small{font-size:.72em;font-weight:600;letter-spacing:.16em;opacity:.78}
.sh-mark{width:16px;height:16px;flex:none;background:#fff;border-radius:3px;padding:1px}
.sh-pages{background:#F5F3EE;background-image:repeating-linear-gradient(to right,transparent 0 2px,rgba(0,0,0,.06) 2px 3px)}
.sh-pr{top:0;height:100%;transform:rotateY(90deg)}
.sh-pt{left:0;transform:rotateX(90deg);background-image:repeating-linear-gradient(to bottom,transparent 0 2px,rgba(0,0,0,.06) 2px 3px)}
.sh-pb{left:0;transform:rotateX(-90deg);background-image:repeating-linear-gradient(to bottom,transparent 0 2px,rgba(0,0,0,.06) 2px 3px);box-shadow:0 0 18px 6px rgba(16,37,74,.22)}

.sh-nav{position:absolute;left:50%;bottom:34px;transform:translateX(-50%);display:flex;align-items:center;gap:16px;z-index:20;transition:opacity .4s}
.shelf.reading .sh-nav{opacity:0;pointer-events:none}
.sh-nav>button{width:44px;height:44px;border-radius:50%;border:1px solid #CFD8EA;background:#fff;color:var(--navy);display:grid;place-items:center;cursor:pointer;transition:transform .2s,border-color .2s}
.sh-nav>button:hover{transform:scale(1.06);border-color:var(--navy)}
.sh-nav svg{width:20px;height:20px}
.sh-dots{display:flex;gap:0}
.sh-dots button{min-width:24px;height:24px;border:0;padding:0 2px;background:none;cursor:pointer;display:grid;place-items:center}
.sh-dots button::before{content:"";width:8px;height:8px;border-radius:99px;background:#B9C4DA;transition:width .3s,background .3s}
.sh-dots button.on::before{width:26px;background:var(--navy)}
.sh-count{display:none;font-size:14px;font-weight:600;color:var(--navy);min-width:64px;text-align:center;font-variant-numeric:tabular-nums}
@media (max-width:600px){.sh-dots{display:none}.sh-count{display:block}}
.sh-close,.sp-close{position:absolute;width:44px;height:44px;border-radius:50%;border:1px solid rgba(16,37,74,.15);background:#fff;cursor:pointer;z-index:30;display:grid;place-items:center}
.sh-close{top:28px;right:28px;opacity:0;pointer-events:none;transition:opacity .4s}
.shelf.reading .sh-close{opacity:1;pointer-events:auto}
.sh-close span,.sp-close span{position:absolute;width:16px;height:1.5px;background:var(--navy);transition:transform .4s cubic-bezier(.16,1,.3,1)}
.sh-close span:first-child,.sp-close span:first-child{transform:rotate(45deg)}
.sh-close span:last-child,.sp-close span:last-child{transform:rotate(-45deg)}
.sh-close:hover span:first-child,.sp-close:hover span:first-child{transform:rotate(135deg)}
.sh-close:hover span:last-child,.sp-close:hover span:last-child{transform:rotate(45deg)}
.sp-close{display:none}

.sh-panel{position:absolute;right:56px;top:50%;width:min(380px,36%);transform:translate(24px,-50%);opacity:0;pointer-events:none;z-index:25;cursor:auto;
  background:#fff;border-radius:24px;padding:30px 30px 26px;box-shadow:0 30px 60px -24px rgba(16,37,74,.35);border:1px solid #E3E8F2;transition:opacity .5s ease .15s,transform .6s cubic-bezier(.16,1,.3,1) .15s}
.sh-panel.on{opacity:1;transform:translate(0,-50%);pointer-events:auto}
.sp-series{font-size:.72rem;font-weight:600;letter-spacing:.2em;text-transform:uppercase;color:var(--blue)}
.sp-title{font-size:1.9rem;font-weight:700;letter-spacing:-.035em;color:var(--navy);margin:6px 0 14px;line-height:1.05}
.sp-facts{list-style:none;display:flex;flex-wrap:wrap;gap:6px;margin-bottom:16px}
.sp-facts li{font-size:.78rem;font-weight:500;padding:5px 11px;border-radius:99px;background:var(--panel);color:var(--text)}
.sp-blurb{color:var(--gray);font-size:1rem;line-height:1.45;margin-bottom:22px}
.sp-act{display:flex;flex-wrap:wrap;gap:14px;align-items:center}
.sp-act .btn{font-size:.95rem;padding:11px 20px}
.sp-act .more{font-size:.98rem}

.series-sec{padding-top:90px}
.series-sec .headline,.certs-sec .headline{margin-bottom:44px}
.series-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:16px}
.ser{background:#fff;border:1px solid #E3E8F2;border-radius:22px;padding:24px 22px 22px;display:flex;flex-direction:column}
.ser-tag{align-self:flex-start;font-size:.72rem;font-weight:600;letter-spacing:.14em;text-transform:uppercase;color:#fff;background:var(--c);padding:5px 10px;border-radius:99px;margin-bottom:16px}
.ser h3{font-size:1.35rem;letter-spacing:-.025em;color:var(--navy);margin-bottom:8px}
.ser p{color:var(--gray);font-size:.95rem;line-height:1.45}
.ser-links{display:flex;gap:14px;flex-wrap:wrap;margin-top:auto;padding-top:18px}
.ser-links a{color:var(--blue);font-weight:600;font-size:.92rem}
.ser-links a::after{content:" ↗";font-weight:400}

.unlock-sec{padding-top:40px}
.unlock-card{display:grid;grid-template-columns:1.1fr 1fr;gap:48px;align-items:center;background:var(--navy);color:#fff;border-radius:32px;padding:56px;position:relative;overflow:hidden}
.unlock-card::after{content:"";position:absolute;right:-60px;bottom:-40px;width:360px;height:260px;background:url(/img/books/math-game-plan-front.webp) center/cover;opacity:.08;transform:rotate(-8deg);border-radius:12px;pointer-events:none}
.unlock-card .kicker{color:var(--gold)}
.unlock-card .lead{color:#C9D3E6;margin:18px 0 26px}
.kit{list-style:none;display:grid;grid-template-columns:1fr 1fr;gap:10px}
.kit li{background:rgba(255,255,255,.07);border:1px solid rgba(255,255,255,.12);border-radius:14px;padding:12px 14px;display:flex;flex-direction:column}
.kit b{font-size:.95rem}
.kit span{font-size:.8rem;color:#A9B7D6}
.unlock-form{position:relative;z-index:1;background:#fff;color:var(--text);border-radius:24px;padding:30px}
.unlock-form .res-form{max-width:none}
.unlock-form .res-list{max-width:none;margin-top:20px}

.certs-sec{text-align:center}
.certs-sec .lead{max-width:44ch;margin:-26px auto 40px}
.cert-fan{position:relative;overflow:visible;height:clamp(240px,34vw,420px);margin:0 auto;max-width:980px}
.cert-fan figure{position:absolute;left:50%;top:6%;width:min(46%,440px);transform:translateX(calc(-50% + var(--x))) rotate(var(--r));transition:transform .5s cubic-bezier(.16,1,.3,1);box-shadow:0 24px 48px -20px rgba(16,37,74,.4);border-radius:6px;overflow:hidden;background:#fff}
.cert-fan figure.top{z-index:2;top:0}
.cert-fan:hover figure{transform:translateX(calc(-50% + var(--x) * 1.12)) rotate(calc(var(--r) * 1.3))}
.cert-fan figure img{width:100%;height:auto}

@media (max-width:900px){
  .shelf{height:560px;border-radius:24px}
  .sh-panel{left:16px;right:16px;top:auto;bottom:16px;width:auto;transform:translateY(20px);padding:20px 20px 18px;border-radius:20px}
  .sh-panel.on{transform:none}
  .sp-title{font-size:1.4rem;margin:4px 0 10px}
  .sp-blurb{font-size:.9rem;margin-bottom:14px}
  .sp-facts{margin-bottom:10px}
  .series-grid{grid-template-columns:1fr 1fr}
  .unlock-card{grid-template-columns:1fr;padding:32px 22px;gap:28px}
}
@media (max-width:900px){ .shelf.reading .sh-track{bottom:300px} .sh-track{transition:bottom .6s cubic-bezier(.16,1,.3,1)} }
@media (max-width:600px){
  .shelf{height:520px}
  .sh-head{top:24px}
  .sh-hint{display:none}
  .sh-line small,.sh-line i{display:none}
  .sh-floor{height:96px}
  .sh-track{bottom:92px}
  .shelf.reading .sh-track{bottom:258px}
  .sh-close{top:16px;right:16px}
  .series-grid{grid-template-columns:1fr}
  .kit{grid-template-columns:1fr}
  .cert-fan figure{width:62%}
}
@media (prefers-reduced-motion:reduce){
  .sh-head,.sh-close,.sh-nav,.sh-panel,.cert-fan figure,.sh-track{transition:none!important}
}
.unlock-card .grad{background:none;-webkit-text-fill-color:var(--gold);color:var(--gold)}
.unlock-card::after{opacity:.05}

/* Mobile type scale for the resources page (matches styles.css) */
@media (max-width:600px){
  .sh-title,.sp-title,.ser h3{font-size:24px!important}
  .sh-series,.sp-series,.ser-tag,.sp-facts li{font-size:12px!important}
  .sp-blurb,.ser p,.kit span,.unlock-form .res-msg,.res-note{font-size:14px!important}
  .kit b,.sp-act .btn,.sp-act .more,.ser-links a{font-size:16px!important}
  .sh-backart strong{font-size:24px}
  .sh-backart span{font-size:14px}
  .sh-backart em{font-size:12px}
}
@media (max-width:900px){ .unlock-card{grid-template-columns:minmax(0,1fr)} .unlock-copy,.unlock-form{min-width:0} }
.certs-sec{overflow:hidden}

/* ===== Series pages (cleared-math.html, cleared-reading-and-writing.html) ===== */
.crumbs{padding-top:96px;font-size:.9rem}
.crumbs ol{list-style:none;display:flex;flex-wrap:wrap;gap:8px;color:var(--gray);justify-content:center}
.crumbs li+li::before{content:"›";margin-right:8px;color:var(--line)}
.crumbs a{color:var(--blue);font-weight:500}
.series-hero{padding-top:28px}
.sub-lead{margin:-24px 0 40px;max-width:52ch}
.bk-sec .headline,.inside-sec .headline,.roles-sec .headline,.faq-sec .headline{margin-bottom:40px}
.bk-grid{display:grid;grid-template-columns:repeat(5,1fr);gap:18px}
.bk{background:#fff;border:1px solid #E3E8F2;border-radius:22px;padding:14px 14px 20px;display:flex;flex-direction:column}
.bk-cover{display:block;border-radius:8px;overflow:hidden;box-shadow:0 18px 30px -18px rgba(16,37,74,.45);transition:transform .3s cubic-bezier(.16,1,.3,1);aspect-ratio:360/465;background:var(--panel)}
.bk-cover img{width:100%;height:100%;object-fit:cover}
.bk-cover:hover{transform:translateY(-4px) rotate(-1deg)}
.bk-body{padding:16px 4px 0;display:flex;flex-direction:column}
.bk h3{font-size:1.2rem;letter-spacing:-.02em;color:var(--navy);margin:2px 0 4px}
.bk-facts{font-size:.85rem;font-weight:600;color:var(--blue);margin-bottom:8px}
.bk p:not(.bk-facts){color:var(--gray);font-size:.92rem;line-height:1.45}
.bk .ser-tag{margin-bottom:10px}
.inside-grid{display:grid;grid-template-columns:1fr 1fr;gap:48px;align-items:start}
.inside-col h3{font-size:1.35rem;letter-spacing:-.025em;color:var(--navy);margin-bottom:16px}
.inside-col>p{color:var(--gray);margin-bottom:18px}
.gp-h{margin-top:36px}
.toc{list-style:none;display:grid;gap:8px}
.toc li{display:flex;gap:14px;align-items:baseline;padding:14px 16px;background:#fff;border:1px solid #E3E8F2;border-radius:14px;font-weight:500}
.toc li span{flex:none;width:28px;font-weight:700;color:var(--blue);font-variant-numeric:tabular-nums}
.unit{border:1px solid #E3E8F2;border-radius:14px;background:#fff;margin-bottom:8px}
.unit summary{list-style:none;cursor:pointer;padding:14px 16px;display:flex;gap:12px;align-items:baseline;font-weight:600;min-height:44px}
.unit summary::-webkit-details-marker{display:none}
.unit summary span{flex:none;font-size:.75rem;font-weight:700;letter-spacing:.12em;text-transform:uppercase;color:var(--red)}
.unit summary small{margin-left:auto;color:var(--gray);font-weight:500;white-space:nowrap}
.unit ol{padding:0 18px 16px 40px;color:var(--gray);display:grid;gap:4px}
.table-wrap{overflow-x:auto;border:1px solid #E3E8F2;border-radius:18px;background:#fff}
.roles{width:100%;border-collapse:collapse;min-width:560px}
.roles th,.roles td{text-align:left;padding:16px 18px;border-bottom:1px solid #EEF1F7;vertical-align:top}
.roles thead th{font-size:.78rem;letter-spacing:.12em;text-transform:uppercase;color:var(--gray);background:var(--panel)}
.roles tbody th{color:var(--navy);font-weight:600}
.roles tbody tr:last-child th,.roles tbody tr:last-child td{border-bottom:0}
.series-faq{margin-top:0}
.series-sec .ser-links a::after{content:" →"}
@media (max-width:1000px){.bk-grid{grid-template-columns:repeat(3,1fr)}.inside-grid{grid-template-columns:1fr}}
@media (max-width:600px){
  .crumbs{padding-top:84px}
  .bk-grid{grid-template-columns:1fr 1fr;gap:12px}
  .bk{padding:10px 10px 16px;border-radius:18px}
  .bk h3{font-size:18px!important}
  .bk-facts,.bk p:not(.bk-facts),.crumbs,.unit summary small,.unit ol,.toc li,.roles th,.roles td,.inside-col>p{font-size:14px!important}
  .unit summary span,.roles thead th{font-size:12px!important}
  .inside-col h3{font-size:24px!important}
  .unit summary{font-size:16px!important}
  .faq summary{font-size:18px!important}
  .sub-lead{margin-top:-20px}
}
.series-list{padding-bottom:20px}
.series-list .headline{margin-bottom:40px}
.sl-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px}
.sl-card{display:flex;flex-direction:column;background:#fff;border:1px solid #E3E8F2;border-radius:24px;padding:28px;color:var(--text);transition:border-color .2s,transform .3s cubic-bezier(.16,1,.3,1)}
.sl-card:hover{border-color:var(--blue);transform:translateY(-2px)}
.sl-card .ser-tag{margin-bottom:14px}
.sl-card h3{font-size:1.5rem;letter-spacing:-.03em;color:var(--navy);margin-bottom:8px}
.sl-card p{color:var(--gray);margin-bottom:16px}
.sl-card ul{list-style:none;display:flex;flex-wrap:wrap;gap:6px;margin-bottom:20px}
.sl-card li{font-size:.82rem;font-weight:500;padding:5px 11px;border-radius:99px;background:var(--panel)}
.sl-card .more{margin-top:auto}
@media (max-width:700px){.sl-grid{grid-template-columns:1fr}}
@media (max-width:600px){.sl-card h3{font-size:24px!important}.sl-card p{font-size:14px!important}.sl-card li{font-size:14px!important}}
.res-note a{color:var(--blue);font-weight:500}

/* Button: liquid metal (see styles.css) on the shelf's round prev/next controls */
.sh-nav>button{--lm-face:linear-gradient(180deg,#FFFFFF 0%,#F4F5F7 55%,#E6E8EC 100%);
  --lm-rim:conic-gradient(from var(--lm),#C9CDD3 0deg,#F6F7F9 22deg,#8E96A3 44deg,#1A2130 64deg,#0B1020 70deg,#FF3B2F 75deg,#FFE04A 80deg,#FFFFFF 84deg,#5BE7FF 89deg,#3D5BFF 95deg,#7A4BFF 100deg,#C9CDD3 112deg,#FFFFFF 142deg,#AEB5C0 170deg,#E8EAED 192deg,#1A2130 226deg,#0B1020 233deg,#FFD23F 240deg,#FF4A2E 245deg,#56E5FF 252deg,#3B4CF0 258deg,#D8DBE0 274deg,#FFFFFF 300deg,#9AA2AE 332deg,#C9CDD3 360deg);
  border:2px solid transparent;background:var(--lm-face) padding-box,var(--lm-rim) border-box;color:#0B1B38;
  box-shadow:0 0 0 1px rgba(16,37,74,.12),inset 0 1px 0 #fff,0 8px 18px -8px rgba(16,37,74,.4);animation:lmSpin 6s linear infinite}
.sh-nav>button:hover{border-color:transparent}
.sp-act .btn{padding:9px 18px}
@media (prefers-reduced-motion:reduce){.sh-nav>button{animation:none}}