/* ============================================================
   CYMOTHOE · common.css
   Shared design system: loaded on every page, before the page's
   own stylesheet (if any). Page CSS files hold only page-unique
   rules and small deltas from this baseline.
   ============================================================ */
:root{
  --bp-deep:#FAFBF9;
  --bp-deep-2:#EDF6F5;
  --bp-panel:#E7F3F5;
  --bp-panel-2:#F3FAFB;
  --bp-line:rgba(18,59,82,.14);
  --bp-line-strong:rgba(18,59,82,.32);
  --ink:#17303F;
  --ink-dim:#4A6B78;
  --ink-faint:#5A7683;
  --cyan:#1FC2C2;
  --cyan-text:#106E78;
  --brass:#E0A94E;
  --danger:#C4453A;
  --ok:#2E9B6F;
  --r:6px;
  --navy:#123B52;
  --navy-2:#0D2E40;
  --sheet-max:73.75rem;
  --font-display:"IBM Plex Sans Condensed",system-ui,sans-serif;
  --font-body:"IBM Plex Sans",Georgia,serif;
  --font-mono:"IBM Plex Mono",ui-monospace,monospace
}
*{box-sizing:border-box;margin:0;padding:0}html{scroll-behavior:smooth}
@media (min-width:900px){
    html{font-size:clamp(13px, calc(100vw / 120), 20px)}
  }
@view-transition{navigation:auto}
@keyframes page-fade-in{from{opacity:0}to{opacity:1}}
body{font-family:var(--font-body);color:var(--ink);background:var(--bp-deep);line-height:1.6;-webkit-font-smoothing:antialiased;min-height:100vh;animation:page-fade-in .35s ease both}
body::before{content:none}
a{color:var(--cyan-text);text-decoration:none}
.skip-link{position:absolute;left:1rem;top:-3rem;z-index:100;background:var(--cyan);color:var(--navy);font-weight:600;padding:.5rem .9rem;border-radius:var(--r);transition:top .15s}
.skip-link:focus{top:.75rem}
.sheet:focus{outline:none}

/* ====================== NAV ====================== */
.helm-nav{position:sticky;top:0;z-index:50;background:linear-gradient(180deg,var(--navy),var(--navy-2));backdrop-filter:blur(8px);border-bottom:1px solid var(--bp-line-strong)}
.helm-nav__inner{max-width:var(--sheet-max);margin:0 auto;display:flex;align-items:center;gap:1.5rem;padding:.55rem 1.25rem}
.brand{display:flex;align-items:center;gap:.6rem;align-self:flex-start}
.brand__mark{width:76px;height:76px;flex:0 0 auto;border-radius:50%;display:block;border:3px solid #F7F2E7;box-shadow:0 4px 14px rgba(0,0,0,.45)}
.helm-nav__links{display:flex;flex-wrap:wrap;gap:.15rem;margin-left:auto;list-style:none}
.helm-nav__links a{font-family:var(--font-display);text-transform:uppercase;letter-spacing:.12em;font-size:.94rem;font-weight:500;color:rgba(255,255,255,.8);padding:.4rem .6rem;border-radius:var(--r);display:inline-block;border:1px solid transparent;transition:.15s}
.helm-nav__links a .idx{font-family:var(--font-mono);font-size:.6rem;color:rgba(255,255,255,.5);margin-right:.3em}
.helm-nav__links a:hover{color:#fff;border-color:rgba(255,255,255,.25)}
.helm-nav__links a[aria-current="page"]{color:var(--navy);background:var(--cyan);border-color:var(--cyan)}
.helm-nav__links a[aria-current="page"] .idx{color:var(--navy);opacity:.7}
.nav-toggle{display:none}
.has-sub{position:relative}
.sub-label{font-family:var(--font-display);text-transform:uppercase;letter-spacing:.12em;font-size:.94rem;font-weight:500;color:rgba(255,255,255,.8);padding:.4rem .6rem;border-radius:var(--r);display:inline-block;border:1px solid transparent;transition:.15s}
button.sub-label{background:none;cursor:pointer;line-height:inherit}
.sub-label::after{content:'▾';margin-left:.4em;font-size:.65em}
.helm-nav a:focus-visible,.sub-label:focus-visible{outline:2px solid var(--cyan);outline-offset:2px}
.sub-label.is-active{color:var(--navy);background:var(--cyan);border-color:var(--cyan)}
.has-sub:hover .sub-label,.has-sub:focus-within .sub-label{color:#fff;border-color:rgba(255,255,255,.25)}
.sub-menu{position:absolute;top:100%;left:0;min-width:190px;display:none;flex-direction:column;list-style:none;background:var(--bp-panel-2);border:1px solid var(--bp-line-strong);border-radius:var(--r);box-shadow:0 10px 24px rgba(0,0,0,.18);z-index:60;padding:.3rem 0}
.has-sub:hover .sub-menu,.has-sub:focus-within .sub-menu{display:flex}
.sub-menu--right{left:auto;right:0}
.sub-menu a{font-family:var(--font-display);text-transform:uppercase;letter-spacing:.08em;font-size:.76rem;font-weight:500;color:var(--ink-dim);padding:.55rem .9rem;display:block;white-space:nowrap;border:none;border-radius:0}
.sub-menu a:hover{color:var(--ink);background:rgba(31,194,194,.1)}
.sub-menu a[aria-current]{color:var(--navy);background:var(--cyan)}
.nav-about{display:none}

/* ====================== SHEET / PAGE FRAME ====================== */
.sheet{max-width:var(--sheet-max);margin:0 auto;padding:0 1.25rem 5rem;position:relative;z-index:1}
.sheet-head{display:flex;align-items:flex-end;justify-content:space-between;gap:1rem;padding:2.4rem 0 1.2rem;border-bottom:1px solid var(--bp-line-strong);margin-bottom:2rem;flex-wrap:wrap}
.sheet-head__eyebrow{font-family:var(--font-mono);font-size:.62rem;letter-spacing:.28em;color:var(--cyan-text);text-transform:uppercase;display:block;margin-bottom:.5rem}
.sheet-head h1{font-family:var(--font-display);font-weight:600;text-transform:uppercase;letter-spacing:.04em;font-size:clamp(2rem,5vw,3.4rem);line-height:.98}
.sheet-head__meta{font-family:var(--font-body);font-size:.78rem;color:var(--ink-dim);text-align:right;letter-spacing:.01em;line-height:1.75}
.sheet-head__meta b{color:var(--ink);font-weight:600}
.lede{max-width:66ch;color:var(--ink-dim);margin-bottom:1.6rem}
/* intro paragraph under a page header or section title */
.sheet-head + p,.learn-tabs + p,.section-title + p{margin-bottom:1.6rem}

/* ====================== TYPE HELPERS ====================== */
h2.t{font-family:var(--font-display);text-transform:uppercase;letter-spacing:.05em;font-weight:600;font-size:1.7rem;margin-bottom:.4rem}
p.body{color:var(--ink-dim);max-width:68ch;margin-bottom:1rem}
p.body b{color:var(--ink)}
.section-rule{display:flex;align-items:center;gap:1rem;margin:3rem 0 1.4rem}
.section-rule .label{font-family:var(--font-mono);font-size:.6rem;letter-spacing:.2em;text-transform:uppercase;color:var(--cyan);flex:0 0 auto}
.section-rule hr{flex:1;border:none;border-top:1px solid var(--bp-line-strong)}
.learn-tabs{display:flex;flex-wrap:wrap;gap:.5rem;margin-bottom:1.6rem}
.learn-tabs a{font-family:var(--font-display);text-transform:uppercase;letter-spacing:.08em;font-size:.78rem;font-weight:500;color:var(--ink-dim);background:var(--bp-panel);border:1px solid var(--bp-line-strong);border-radius:var(--r);padding:.45rem .85rem;transition:.15s}
.learn-tabs a:hover{color:var(--ink);border-color:var(--cyan)}
.learn-tabs a[aria-current="page"]{background:var(--cyan);color:var(--navy);border-color:var(--cyan)}
/* filter chips (Glossary sheet filter, Directories area filter) */
.cat-filter{display:flex;flex-wrap:wrap;gap:.5rem;margin-bottom:1.8rem}
.cat-chip{font-family:var(--font-body);font-size:.8rem;font-weight:500;color:var(--ink-dim);background:var(--bp-panel);border:1px solid var(--bp-line-strong);border-radius:var(--r);padding:.4rem .8rem;cursor:pointer;transition:.15s}
.cat-chip:hover{color:var(--ink);border-color:var(--cyan)}
.cat-chip.active,.cat-chip[aria-pressed="true"]{background:var(--cyan);color:var(--navy);border-color:var(--cyan)}
.cat-chip__count{font-family:var(--font-mono);font-size:.68rem;opacity:.7;margin-left:.25em}
/* collapsible category sections (News, Directories): a full-width header button,
   aria-expanded drives the chevron; the list after it is only rendered when open */
.cat-toggle{display:flex;align-items:center;justify-content:space-between;gap:1rem;width:100%;margin:2.4rem 0 0;padding:1rem 0;background:none;border:none;border-bottom:2px solid var(--bp-line-strong);cursor:pointer;text-align:left;font-family:var(--font-display);text-transform:uppercase;letter-spacing:.03em;font-size:1.5rem;font-weight:600;color:var(--ink);transition:.15s}
.cat-section:first-of-type .cat-toggle{margin-top:1.6rem}
.cat-toggle:hover{color:var(--cyan-text);border-color:var(--cyan)}
.cat-toggle__count{font-family:var(--font-mono);font-size:.85rem;font-weight:400;letter-spacing:.04em;color:var(--cyan-text);margin-left:.7rem}
.cat-toggle__chevron{font-family:var(--font-mono);font-size:1rem;color:var(--cyan-text);flex:0 0 auto;transition:transform .2s}
.cat-toggle__chevron::before{content:'▾'}
.cat-toggle[aria-expanded="true"] .cat-toggle__chevron{transform:rotate(180deg)}
@media(max-width:600px){.cat-toggle{font-size:1.15rem}.cat-toggle__count{font-size:.72rem}}
.empty-state{border:1px dashed var(--bp-line-strong);border-radius:var(--r);color:var(--ink-faint);font-family:var(--font-mono);font-size:.8rem;padding:2.5rem 1.5rem;text-align:center}
.cat-badge{border-radius:var(--r);display:inline-block;font-family:var(--font-mono);font-size:.58rem;letter-spacing:.1em;margin-bottom:.5rem;padding:.2rem .5rem;text-transform:uppercase}

/* ====================== BUTTONS ====================== */
.btn{font-family:var(--font-body);text-transform:none;letter-spacing:.01em;font-size:.85rem;font-weight:600;padding:.6rem 1.1rem;border-radius:var(--r);border:1px solid var(--cyan);cursor:pointer;transition:.15s;display:inline-block;white-space:nowrap}
.btn--solid{background:var(--cyan);color:var(--navy)}
.btn--solid:hover{filter:brightness(1.08)}
.btn--ghost{background:transparent;color:var(--navy)}
.btn--ghost:hover{background:rgba(28,100,136,.1)}
.btn:disabled{opacity:.5;cursor:not-allowed}
.btn--sm{font-size:.72rem;padding:.4rem .75rem}

/* ====================== FORMS ====================== */
.field{margin-bottom:1rem}
.field label{display:block;font-family:var(--font-mono);font-size:.62rem;letter-spacing:.1em;text-transform:uppercase;color:var(--ink-dim);margin-bottom:.4rem}
.field input{width:100%;font-family:var(--font-body);font-size:.95rem;color:var(--ink);background:rgba(255,255,255,.7);border:1px solid var(--bp-line-strong);border-radius:var(--r);padding:.6rem .7rem;outline:none;transition:.15s}
.field input:focus{border-color:var(--cyan)}

/* ====================== SHEET-END NAV (practice / prev / next) ====================== */
.sheet-next{display:grid;grid-template-columns:repeat(auto-fit,minmax(min(100%,260px),1fr));gap:.75rem;margin-top:3.5rem;padding-top:1.6rem;border-top:1px solid var(--bp-line-strong)}
.sheet-next a{display:flex;flex-direction:column;gap:.3rem;padding:1rem 1.15rem;border:1px solid var(--bp-line-strong);border-radius:var(--r);background:var(--bp-panel-2);font-family:var(--font-display);text-transform:uppercase;letter-spacing:.05em;font-size:1.05rem;font-weight:600;color:var(--navy);transition:.15s}
.sheet-next a:hover{border-color:var(--cyan);background:var(--bp-panel)}
.sheet-next__eyebrow{font-family:var(--font-mono);font-size:.6rem;font-weight:400;letter-spacing:.16em;color:var(--cyan-text)}
.sheet-next__quiz{background:var(--cyan) !important;border-color:var(--cyan) !important}
.sheet-next__quiz .sheet-next__eyebrow{color:var(--navy)}
.sheet-next__quiz:hover{filter:brightness(1.06)}
.sheet-next__next{text-align:right;align-items:flex-end}

/* ====================== FOOTER ====================== */
.site-footer{margin-top:3rem;border-radius:var(--r);overflow:hidden;background:linear-gradient(180deg,var(--navy),var(--navy-2))}
.site-footer__inner{display:flex;flex-direction:column;align-items:center;text-align:center;gap:.9rem;padding:1.4rem 1.6rem}
.site-footer__brand{display:flex;flex-direction:column;align-items:center;gap:.2rem}
.site-footer .tb-brand{font-family:var(--font-display);letter-spacing:.28em;font-size:.9rem;color:#fff;text-transform:uppercase}
.site-footer__tag{font-family:var(--font-mono);font-size:.58rem;letter-spacing:.06em;color:rgba(255,255,255,.55)}
.site-footer__legal{width:100%;display:flex;flex-direction:column;align-items:center;gap:.4rem;border-top:1px solid rgba(255,255,255,.12);padding-top:.8rem}
.site-footer__legal p{font-family:var(--font-mono);font-size:.6rem;color:rgba(255,255,255,.45);letter-spacing:.02em;line-height:1.5;margin:0}
.site-footer__legal a{color:rgba(255,255,255,.75);text-decoration:underline}
.site-footer__legal a:hover{color:var(--cyan)}

/* ====================== RESPONSIVE (<=880px) ====================== */
@media(max-width:880px){
.sub-label{display:flex;justify-content:space-between;align-items:center;width:100%;padding:.85rem 1.25rem;border-bottom:1px solid rgba(255,255,255,.08) !important;border-radius:0}
.sub-menu a:hover{color:#fff !important;background:rgba(255,255,255,.08) !important}
input.nav-toggle{display:block;position:absolute;width:1px;height:1px;opacity:0;pointer-events:none}
#nav-switch:focus-visible+label.nav-toggle{outline:2px solid var(--cyan);outline-offset:2px}
#nav-switch:checked~.helm-nav__links{max-height:720px}
.helm-nav__links{position:absolute;top:100%;right:0;left:0;flex-direction:column;gap:0;background:rgba(13,46,64,.98) !important;border-bottom:1px solid rgba(255,255,255,.1) !important;max-height:0;overflow:hidden;transition:max-height .3s}
.learn-tabs a{white-space:nowrap}
.helm-nav__links a{border-radius:0;padding:.85rem 1.25rem;border-bottom:1px solid rgba(255,255,255,.08) !important}
.sub-menu a{padding:.7rem 1.25rem .7rem 2.2rem;border-bottom:1px solid rgba(255,255,255,.08) !important;color:rgba(255,255,255,.78) !important}
.nav-toggle{display:block;margin-left:auto;background:none;border:1px solid var(--bp-line-strong);color:#fff !important;font-family:var(--font-mono);font-size:.7rem;letter-spacing:.15em;padding:.45rem .7rem;border-radius:var(--r);cursor:pointer;text-transform:uppercase;border-color:rgba(255,255,255,.3) !important}
.learn-tabs{flex-wrap:nowrap;overflow-x:auto;-webkit-overflow-scrolling:touch;padding-bottom:.3rem}
.sub-menu{position:static;display:flex;max-height:none;box-shadow:none;border:none;border-radius:0;background:rgba(255,255,255,.06) !important}
}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}body{animation:none}@view-transition{navigation:none}}