/* LearnSCADA Books. Change the look here: everything hangs off these tokens. */
:root{
  --bg:#0f1a26; --bg-2:#132234; --panel:#172a3d; --panel-line:rgba(148,178,209,.18);
  --ink:#e6edf3; --ink-dim:rgba(230,237,243,.72); --rule:rgba(148,178,209,.22);
  --amber:#f0a92e; --amber-deep:#c98a1c; --signal:#38bdf8; --ledge:#243a52;
  --display:'IBM Plex Sans',system-ui,-apple-system,'Segoe UI',Roboto,sans-serif;
  --text:'IBM Plex Sans',system-ui,-apple-system,'Segoe UI',Roboto,sans-serif;
  --mono:'IBM Plex Mono',Consolas,'Courier New',monospace;
}
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg) linear-gradient(180deg,var(--bg-2) 0,var(--bg) 520px) no-repeat;
  color:var(--ink);font-family:var(--text);font-size:18px;line-height:1.6;min-height:100vh}
a{color:var(--signal)}
a:focus-visible,button:focus-visible{outline:3px solid var(--amber);outline-offset:3px}
img{max-width:100%;display:block}

.masthead{max-width:1180px;margin:0 auto;padding:1.2rem 1.5rem;display:flex;justify-content:space-between;align-items:center;gap:1rem;flex-wrap:wrap}
.brand{font-family:var(--display);font-weight:700;font-size:1.3rem;color:var(--ink);text-decoration:none;display:inline-flex;align-items:center;gap:.6rem;letter-spacing:.01em}
.brand span{color:var(--amber);font-weight:500}
.brand-mark{width:1.15rem;height:1.15rem;border:2px solid var(--amber);border-radius:3px;position:relative;display:inline-block}
.brand-mark::after{content:"";position:absolute;left:3px;right:3px;top:50%;height:2px;background:var(--signal);transform:translateY(-50%)}
.home-link{font-size:.92rem;color:var(--ink-dim);font-family:var(--mono);text-decoration:none}
.home-link:hover{color:var(--amber)}

main{max-width:1180px;margin:0 auto;padding:0 1.5rem 4rem}
.hero{max-width:44rem;padding:2.2rem 0 1.2rem}
.hero h1{font-family:var(--display);font-weight:700;font-size:clamp(2rem,4.8vw,3.2rem);line-height:1.1;margin:0 0 1rem;letter-spacing:-.01em}
.hero p{margin:0;color:var(--ink-dim);font-size:1.08rem;max-width:38rem}

.filters{display:flex;flex-wrap:wrap;gap:.55rem;padding:1.2rem 0 1.8rem;border-bottom:1px solid var(--rule);margin-bottom:2.4rem}
.chip{font:inherit;font-family:var(--mono);font-size:.88rem;color:var(--ink);background:transparent;border:1px solid var(--rule);border-radius:6px;padding:.35rem .9rem;cursor:pointer}
.chip:hover{border-color:var(--amber);color:var(--amber)}
.chip[aria-pressed="true"]{background:var(--amber);border-color:var(--amber);color:#1a1200;font-weight:500}

/* the shelf */
.shelf{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:repeat(auto-fill,minmax(170px,1fr));gap:2.6rem 1.8rem}
.book[hidden]{display:none}
.book a{display:flex;flex-direction:column;text-decoration:none;color:var(--ink);height:100%}
.cover-wrap{position:relative;display:block}
.book .cover{aspect-ratio:2/3;width:100%;object-fit:contain;background:#0a121b;border-radius:3px;
  box-shadow:0 14px 18px -10px rgba(0,0,0,.8),0 0 0 1px var(--panel-line);
  transform-origin:bottom center;transition:transform .25s ease,box-shadow .25s ease}
.book a::after{content:"";display:block;height:5px;margin:-1px -.4rem 0;border-radius:0 0 3px 3px;
  background:linear-gradient(180deg,var(--ledge),#141f2c);box-shadow:0 6px 10px rgba(0,0,0,.45);order:1}
.book .book-title{order:2;font-family:var(--display);font-weight:600;font-size:1rem;line-height:1.3;margin-top:.85rem}
.book a:hover .cover,.book a:focus-visible .cover,.book a:hover .cover-blank{transform:translateY(-6px);box-shadow:0 22px 24px -12px rgba(0,0,0,.85),0 0 0 1px var(--amber)}
.book a:hover .book-title{color:var(--amber)}

.cover-blank{aspect-ratio:2/3;width:100%;background:linear-gradient(160deg,var(--panel),var(--bg-2));border:1px solid var(--panel-line);
  display:flex;align-items:center;justify-content:center;padding:1rem;text-align:center;border-radius:3px}
.cover-blank span{font-family:var(--display);font-weight:700;font-size:1.15rem;color:var(--amber);line-height:1.2}

.detail{padding-top:1rem}
.back{display:inline-block;margin:1rem 0 2rem;font-size:.95rem;font-family:var(--mono);text-decoration:none}
.back:hover{text-decoration:underline}
.back::before{content:"\2039\00a0"}
.detail-grid{display:grid;grid-template-columns:minmax(220px,340px) 1fr;gap:3.5rem;align-items:start}
.detail-cover{position:sticky;top:1.5rem}
.cover-lg{width:100%;border-radius:4px;box-shadow:0 24px 30px -14px rgba(0,0,0,.85),0 0 0 1px var(--panel-line)}
.detail-text{max-width:40rem}
.detail h1{font-family:var(--display);font-weight:700;font-size:clamp(1.9rem,4.2vw,2.8rem);line-height:1.12;margin:0 0 .7rem;letter-spacing:-.01em}
.subtitle{font-family:var(--display);font-weight:400;font-size:1.25rem;line-height:1.4;color:var(--amber);margin:0 0 1rem}
.byline{color:var(--ink-dim);margin:0 0 1.8rem;font-family:var(--mono);font-size:.95rem}
.buy{display:flex;flex-wrap:wrap;gap:.8rem;margin-bottom:2.2rem}
.btn{font-size:1rem;padding:.7rem 1.4rem;border:1px solid var(--amber);border-radius:6px;text-decoration:none;color:var(--amber);font-weight:600;font-family:var(--display)}
.btn:hover{background:rgba(240,169,46,.12)}
.btn-primary{background:var(--amber);color:#1a1200}
.btn-primary:hover{background:#f6bf5a}
.blurb p{margin:0 0 1.1rem}
.facts{display:grid;grid-template-columns:max-content 1fr;gap:.4rem 1.5rem;margin:2rem 0 0;padding-top:1.5rem;border-top:1px solid var(--rule);font-size:.95rem}
.facts dt{color:var(--ink-dim);font-family:var(--mono);font-size:.85rem;padding-top:.15rem}
.facts dd{margin:0}

.foot{max-width:1180px;margin:0 auto;padding:2rem 1.5rem 3rem;border-top:1px solid var(--rule);color:var(--ink-dim);font-size:.92rem;display:flex;justify-content:space-between;flex-wrap:wrap;gap:1rem}
.foot p{margin:0}

@media (max-width:720px){
  body{font-size:17px}
  .shelf{grid-template-columns:repeat(auto-fill,minmax(130px,1fr));gap:2.2rem 1.2rem}
  .detail-grid{grid-template-columns:1fr;gap:2rem}
  .detail-cover{position:static;max-width:260px}
}
@media (prefers-reduced-motion:reduce){.book .cover{transition:none}}

/* coming soon */
.soon-badge{order:4;align-self:flex-start;margin-top:.45rem;background:var(--panel);border:1px solid var(--rule);color:var(--ink-dim);font-family:var(--mono);font-size:.68rem;
  letter-spacing:.06em;text-transform:uppercase;padding:.2rem .55rem;border-radius:4px}
.is-soon .cover,.is-soon .cover-blank{filter:saturate(.8) brightness(.85)}
.book-meta{order:3;font-size:.85rem;color:var(--ink-dim);margin-top:.15rem;font-family:var(--mono)}
.soon{display:inline-block;border:1px dashed var(--rule);color:var(--ink-dim);border-radius:6px;padding:.55rem 1.1rem;margin:0;font-style:normal;font-weight:600;font-family:var(--mono);font-size:.9rem}

/* series page */
.series-h1{font-family:var(--display);font-weight:700;font-size:clamp(1.9rem,4.2vw,2.8rem);line-height:1.12;margin:0 0 .5rem;letter-spacing:-.01em}
.series-blurb{max-width:44rem;margin-top:.5rem}
.vols{list-style:none;margin:2rem 0 0;padding:0;display:grid;gap:2rem}
.vol{display:grid;grid-template-columns:120px 1fr;gap:1.5rem;align-items:start;padding-bottom:2rem;border-bottom:1px solid var(--rule)}
.cover-sm{width:100%;aspect-ratio:2/3;object-fit:contain;background:#0a121b;border-radius:3px;box-shadow:0 12px 16px -10px rgba(0,0,0,.85),0 0 0 1px var(--panel-line)}
.vol-cover .cover-blank{font-size:.8rem}
.vol h2{font-family:var(--display);font-weight:600;font-size:1.3rem;margin:0 0 .3rem}
.vol h2 a{color:var(--ink);text-decoration:none}
.vol h2 a:hover{color:var(--amber)}
.vol-no{display:inline-block;min-width:2.1rem;margin-right:.5rem;font-family:var(--mono);font-weight:500;font-size:.85rem;color:var(--amber);border:1px solid var(--amber);border-radius:4px;text-align:center;padding:.05rem .3rem;vertical-align:middle}
.vol .subtitle{font-size:1.02rem;margin:0 0 .9rem}
.buy-compact{margin-bottom:0}
.buy-compact .btn{font-size:.92rem;padding:.5rem 1rem}
@media (max-width:720px){.vol{grid-template-columns:90px 1fr;gap:1rem}}
.vol-cover{text-decoration:none;display:block}

/* ---------- Phase 2: member features (rendered only when MEMBERS_ENABLED = "1") ---------- */
.member-pdf{margin:1rem 0 0;padding:.9rem 1rem;border:1px dashed rgba(240,169,46,.55);border-radius:8px;display:flex;flex-wrap:wrap;gap:.6rem;align-items:center}
.member-pdf .member-note{flex-basis:100%;margin:0;font-size:.95rem;opacity:.9}
.member-pdf .member-out{color:var(--amber);text-decoration:underline;margin-left:.3rem}

.mast-right{display:flex;align-items:center;gap:1.1rem;flex-wrap:wrap}
.acct{display:inline-flex;align-items:center;min-height:2.2rem}
.acct-signin{font-size:.92rem;font-weight:600;color:var(--amber);border:1px solid var(--amber);border-radius:6px;padding:.35rem 1rem;text-decoration:none}
.acct-signin:hover{background:var(--amber);color:#1a1200}
.acct-badge{width:2.1rem;height:2.1rem;border-radius:50%;background:var(--amber);color:#1a1200;display:inline-flex;align-items:center;justify-content:center;font-weight:700;margin-right:.55rem}
.acct-text{display:flex;flex-direction:column;line-height:1.15}
.acct-name{font-size:.9rem;color:var(--ink);max-width:14rem;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.acct-tier{font-size:.75rem;color:var(--amber);letter-spacing:.03em;font-family:var(--mono)}

.lib-flag{order:5;align-self:flex-start;margin-top:.45rem;border:1px solid var(--amber);color:var(--amber);font-family:var(--mono);font-size:.68rem;font-weight:500;letter-spacing:.06em;text-transform:uppercase;padding:.15rem .5rem;border-radius:4px}
.lib-flag.free-flag{background:var(--signal);border-color:var(--signal);color:#04202e}
.lib-flag + .lib-flag{margin-top:.3rem}

.top-row{display:grid;grid-template-columns:minmax(0,1fr) 22rem;gap:2rem;align-items:start}
.top-row-single{grid-template-columns:1fr}
.top-row .hero{max-width:none}
.top-row-single .hero{max-width:44rem}
.member-box{margin-top:2rem;border:1px solid rgba(240,169,46,.45);border-radius:10px;padding:1rem 1.15rem;background:rgba(0,0,0,.22)}
.member-box h2{font-family:var(--display);font-size:1.15rem;margin:0 0 .8rem;color:var(--amber)}
.mb-plan{padding:.6rem 0;border-top:1px solid rgba(240,169,46,.22)}
.mb-plan h3{font-family:var(--display);font-size:1rem;margin:0 0 .3rem;display:flex;justify-content:space-between;gap:.5rem;align-items:baseline}
.mb-price{font-family:var(--mono);font-size:.82rem;color:var(--amber);font-weight:500;white-space:nowrap}
.mb-plan p{margin:0;font-size:.9rem;color:var(--ink-dim);line-height:1.45}
.mb-count{color:var(--ink)}
.lib-flag.mb-tag{display:inline-block;margin:0 .1rem;font-size:.6rem;padding:.05rem .35rem;vertical-align:1px}
.mb-actions{border-top:1px solid rgba(240,169,46,.22);padding-top:.8rem;display:flex;flex-direction:column;gap:.55rem}
.mb-offer{margin:0;font-size:.9rem;color:var(--ink)}
.mb-actions .btn{text-align:center;font-size:.95rem;padding:.6rem 1rem}
.mb-signin{margin:.1rem 0 0;font-size:.85rem;color:var(--ink-dim)}
.mb-signin a{color:var(--amber)}
@media (max-width:860px){.top-row{grid-template-columns:1fr;gap:0}.member-box{margin:0 0 1.5rem}}
.top-row + .shelf{margin-top:1.5rem}

/* ---------- update-2: store, legend, join, account ---------- */
.tag-row{order:6;display:flex;flex-wrap:wrap;gap:.3rem;margin-top:.45rem}
.tag-row .lib-flag{order:0;margin:0}
.lib-flag.price-flag{border-color:var(--ink-dim);color:var(--ink)}
.lib-flag.pro-flag{background:var(--amber);border-color:var(--amber);color:#1a1200}
.lib-flag.sample-flag{border-color:var(--signal);color:var(--signal)}
.soon-badge.mb-tag{order:0;margin:0;font-size:.6rem;padding:.05rem .35rem}
.legend-h{margin-top:1.1rem!important}
.legend{display:grid;grid-template-columns:max-content 1fr;gap:.45rem .7rem;margin:0;font-size:.85rem;color:var(--ink-dim);align-items:center}
.legend dt{margin:0}.legend dd{margin:0}
.was{color:var(--ink-dim);text-decoration:line-through;margin-left:.5rem;font-family:var(--mono);font-size:.95rem}
.buy-form{display:inline-flex;align-items:center;gap:.2rem;margin:0}
.buy-form .btn,.pro-buttons .btn{cursor:pointer;font-family:var(--display)}
.member-pdf .buy-form{flex-basis:auto}
.sample-line{flex-basis:100%}
.sample-link{color:var(--signal);font-weight:600}
.flash{background:rgba(240,169,46,.14);border:1px solid rgba(240,169,46,.5);border-radius:8px;padding:.7rem 1rem;margin:0 0 1.2rem;font-size:.98rem}
.flash.ok{border-color:var(--signal);background:rgba(56,189,248,.12)}
.also{margin-top:3rem;padding-top:1.5rem;border-top:1px solid var(--rule)}
.also h2{font-family:var(--display);font-size:1.15rem;margin:0 0 1rem;color:var(--ink-dim)}
.also-list{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:1rem}
.also-list a{display:flex;gap:.8rem;align-items:center;text-decoration:none;color:var(--ink);font-family:var(--display);font-weight:600;font-size:.95rem}
.also-list a:hover{color:var(--amber)}
.cover-xs{width:56px;aspect-ratio:2/3;object-fit:cover;border-radius:2px;box-shadow:0 6px 10px -6px rgba(0,0,0,.8);flex:none}
.also-list .cover-blank.cover-xs span{font-size:.55rem}
.acct-link{display:inline-flex;align-items:center;text-decoration:none}
.join .join-grid{display:grid;grid-template-columns:1fr 1fr;gap:3rem;margin-top:.5rem}
.join h1{font-family:var(--display);font-size:1.7rem;margin:0 0 .8rem}
.join h2,.account h2{font-family:var(--display);font-size:1.15rem;margin:1.6rem 0 .5rem;color:var(--amber)}
.join-form label{display:block;font-family:var(--mono);font-size:.85rem;color:var(--ink-dim);margin-bottom:.3rem}
.join-form input[type=email]{width:100%;max-width:26rem;font:inherit;padding:.65rem .8rem;border:1px solid var(--rule);border-radius:6px;background:#0a121b;color:var(--ink);margin-bottom:.7rem}
.join-form .btn{cursor:pointer}
.perks{margin:0;padding-left:1.2rem;color:var(--ink-dim)}
.perks li{margin:.25rem 0}
.pro-buttons{display:flex;flex-wrap:wrap;gap:.7rem;margin:1rem 0 .5rem}
.pro-buttons form{margin:0}
.account h1{font-family:var(--display);font-size:1.9rem;margin:0 0 .5rem}
.acct-shelf{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:1rem}
.acct-shelf li{display:flex;gap:.8rem;align-items:center;background:rgba(0,0,0,.18);border:1px solid var(--panel-line);border-radius:8px;padding:.6rem}
.acct-shelf a{font-weight:600}
.btn-sm{font-size:.82rem;padding:.35rem .7rem;margin-top:.4rem;display:inline-block}
.orders{width:100%;border-collapse:collapse;font-size:.92rem;max-width:40rem}
.orders th,.orders td{text-align:left;padding:.45rem .6rem;border-bottom:1px solid var(--rule)}
.orders th{font-family:var(--mono);font-weight:500;font-size:.8rem;color:var(--ink-dim)}
.orders .refunded td{color:var(--ink-dim);text-decoration:line-through}
@media (max-width:720px){.join .join-grid{grid-template-columns:1fr;gap:1.5rem}}