/* AI4.FILM, landing page for the APS standard.
   Shared stylesheet for the Polish (/) and English (/en/) pages. */

:root{
  --paper:#FBFAF7;
  --ink:#172033;
  --night:#16223D;
  --night-2:#1E2D4F;
  --line:#D8D6CF;
  --pen:#2350B8;
  --pen-light:#AFC6F5;
  --muted:#5A6272;
  /* script revision page colours, in industry order */
  --rev-white:#FFFFFF;
  --rev-blue:#CFE0F5;
  --rev-pink:#F4D2DB;
  --rev-yellow:#F3E7A1;
  --sans:"Archivo", "Helvetica Neue", Arial, sans-serif;
  --script:"Courier Prime", "Courier New", Courier, monospace;
  --wrap:72rem;
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--paper);color:var(--ink);font-family:var(--sans);font-size:1.0625rem;line-height:1.6;font-variation-settings:"wdth" 100}
a{color:var(--pen);text-underline-offset:.18em}
a:hover{text-decoration-thickness:2px}
:focus-visible{outline:3px solid var(--pen);outline-offset:3px}
.wrap{max-width:var(--wrap);margin:0 auto;padding:0 1.5rem}

/* skip link */
.skip{position:absolute;left:-9999px;top:0;z-index:10;background:var(--ink);color:var(--paper);padding:.7rem 1rem;text-decoration:none}
.skip:focus{left:0}

/* header */
.top{border-bottom:1px solid var(--line)}
.top .wrap{display:flex;align-items:center;justify-content:space-between;gap:1rem;min-height:4rem;flex-wrap:wrap}
.brand{font-weight:800;font-variation-settings:"wdth" 70;font-size:1.35rem;letter-spacing:.01em;color:var(--ink);text-decoration:none}
.top nav{display:flex;align-items:center;gap:1.25rem;font-size:.95rem}
.top nav a{color:var(--ink);text-decoration:none}
.top nav a:hover{text-decoration:underline}
.lang{display:inline-flex;border:1px solid var(--ink);border-radius:2px;overflow:hidden;font-size:.85rem;font-weight:600}
.lang a,.lang span{padding:.3rem .6rem;text-decoration:none;color:var(--ink)}
.lang a:hover{background:#fff;text-decoration:underline}
.lang .here{background:var(--ink);color:var(--paper)}

/* hero */
.hero .wrap{display:grid;grid-template-columns:minmax(0,1.15fr) minmax(0,1fr);gap:3.5rem;align-items:center;padding-top:3.5rem;padding-bottom:4rem}
.hero h1{font-size:clamp(2.1rem,5.4vw,4.4rem);line-height:1;font-weight:800;font-variation-settings:"wdth" 64;margin:0 0 1.5rem;letter-spacing:-.005em;overflow-wrap:break-word}
.lead{font-size:1.2rem;max-width:36rem;margin:0 0 2rem;color:var(--ink)}
.actions{display:flex;flex-wrap:wrap;gap:.75rem}
.btn{display:inline-block;padding:.8rem 1.2rem;font-weight:600;text-decoration:none;border:2px solid var(--ink);border-radius:2px}
.btn.primary{background:var(--ink);color:var(--paper)}
.btn.primary:hover{background:var(--night-2)}
.btn.ghost{color:var(--ink)}
.btn.ghost:hover{background:#fff}
.facts{margin:1.75rem 0 0;font-size:.95rem;color:var(--muted)}
.facts a{color:var(--pen)}

/* the register sheet: the one bold element */
.sheet{background:#fff;border:1px solid var(--ink);font-family:var(--script);font-size:.95rem;line-height:1.45;box-shadow:6px 6px 0 var(--rev-blue)}
.sheet .sheet-head{display:flex;justify-content:space-between;align-items:baseline;gap:1rem;padding:.8rem 1rem;border-bottom:2px solid var(--ink);font-weight:700}
.sheet .sheet-head small{font-weight:400;color:var(--muted)}
.sheet dl{margin:0;display:grid;grid-template-columns:minmax(9rem,38%) 1fr}
.sheet dt,.sheet dd{margin:0;padding:.5rem 1rem;border-bottom:1px solid var(--line)}
.sheet dt{color:var(--muted);border-right:1px solid var(--line)}
.sheet dd .req{display:block;color:var(--muted);font-size:.82em;margin-top:.15rem}
.sheet figcaption{padding:.7rem 1rem;font-size:.85rem;color:var(--muted)}

/* section rhythm */
section{padding:5rem 0}
h2{font-size:clamp(1.7rem,3.6vw,2.8rem);line-height:1.08;font-weight:800;font-variation-settings:"wdth" 68;margin:0 0 1.75rem;overflow-wrap:break-word}
.prose{max-width:40rem}
.prose p{margin:0 0 1.15rem}

/* why: dark */
.why{background:var(--night);color:#EEF1F7}
.why a{color:var(--pen-light)}
.why .prose p:first-of-type{font-size:1.25rem;line-height:1.5}
.sig{margin-top:2rem;padding-top:1rem;border-top:1px solid rgba(255,255,255,.25);font-size:.95rem;color:#C9D0DE}
.sig strong{color:#fff;font-weight:600}

/* components */
.parts{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1.6fr);gap:3rem}
.parts dl{margin:0}
.parts dt{font-weight:700;font-size:1.1rem;padding-top:1.1rem;border-top:1px solid var(--line)}
.parts dd{margin:.25rem 0 1.1rem;color:var(--ink)}
.parts code,.cite code{font-family:var(--script);font-size:.92em}
.parts code{background:#EFEDE6;padding:.05em .3em}

/* layers: a real sequence, input to output */
.layers{margin-top:4rem}
.layers h3{font-size:1.35rem;font-weight:700;margin:0 0 1rem}
.flow{display:grid;grid-template-columns:1fr auto 1.25fr auto 1fr;align-items:stretch;gap:.75rem}
.flow .step{border:1px solid var(--line);padding:1.1rem 1.2rem;background:#fff}
.flow .step.aps{border:2px solid var(--ink)}
.flow .step b{display:block;font-size:1.05rem}
.flow .step span{display:block;color:var(--muted);font-size:.95rem}
.flow .arrow{align-self:center;font-size:1.4rem;color:var(--muted);text-align:center}
.note{color:var(--muted);font-size:.95rem;max-width:44rem;margin-top:1rem}

/* versions */
.versions{border-top:1px solid var(--line)}
.revs{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:0;border:1px solid var(--ink)}
.revs li{padding:1.2rem 1.1rem 1.4rem;border-right:1px solid var(--ink)}
.revs li:last-child{border-right:0}
.revs .v{font-family:var(--script);font-weight:700;font-size:1.25rem}
.revs .d{font-family:var(--script);font-size:.9rem;color:var(--muted);margin-bottom:.6rem}
.revs p{margin:0;font-size:.97rem}
.revs .doi{display:block;margin-top:.5rem;font-family:var(--script);font-size:.82rem;color:var(--muted);overflow-wrap:break-word}
.r-white{background:var(--rev-white)}
.r-blue{background:var(--rev-blue)}
.r-pink{background:var(--rev-pink)}
.r-yellow{background:repeating-linear-gradient(135deg,var(--rev-yellow) 0 14px,#F7EEBC 14px 28px)}

/* get involved: dark */
.join{background:var(--night);color:#EEF1F7}
.join a{color:var(--pen-light)}
.join ul{list-style:none;margin:0;padding:0;max-width:44rem}
.join li{padding:1rem 0;border-top:1px solid rgba(255,255,255,.2)}
.join li b{display:block;color:#fff;font-size:1.1rem}
.cite{margin-top:2.5rem;font-size:.95rem;color:#C9D0DE;max-width:44rem}
.cite code{color:#fff;overflow-wrap:break-word}

footer.site{background:var(--night);color:#AEB7C8;font-size:.9rem;border-top:1px solid rgba(255,255,255,.15)}
footer.site .wrap{display:flex;flex-wrap:wrap;justify-content:space-between;gap:1rem;padding-top:1.5rem;padding-bottom:2rem}
footer.site a{color:#D5DDF0}

/* keyboard focus has to stay visible on the dark sections too */
.why :focus-visible,.join :focus-visible,footer.site :focus-visible{outline-color:var(--pen-light)}

/* not found */
.gone{min-height:60vh;display:flex;align-items:center}
.gone .wrap{width:100%}
.gone h1{font-size:clamp(2rem,5vw,3.4rem);font-weight:800;font-variation-settings:"wdth" 64;margin:0 0 1rem;line-height:1.05}
.gone p{max-width:36rem;margin:0 0 .75rem}
.gone .actions{margin-top:2rem}

@media (max-width:900px){
  .hero .wrap{grid-template-columns:1fr;gap:2.5rem;padding-top:3rem;padding-bottom:3.5rem}
  .parts{grid-template-columns:1fr;gap:1rem}
  .flow{grid-template-columns:1fr}
  .flow .arrow{transform:rotate(90deg);justify-self:center}
  .revs{grid-template-columns:1fr 1fr}
  .revs li:nth-child(2){border-right:0}
  .revs li:nth-child(-n+2){border-bottom:1px solid var(--ink)}
  section{padding:3.5rem 0}
}
@media (max-width:560px){
  .top nav .hide-sm{display:none}
  .revs{grid-template-columns:1fr}
  .revs li{border-right:0;border-bottom:1px solid var(--ink)}
  .revs li:last-child{border-bottom:0}
  .sheet dl{grid-template-columns:1fr}
  .sheet dt{border-right:0;border-bottom:0;padding-bottom:0}
}
@media (max-width:400px){
  .wrap{padding:0 1.15rem}
  body{font-size:1rem}
  .lead{font-size:1.1rem}
  .btn{padding:.7rem 1rem}
  .actions .btn{width:100%;text-align:center}
}
@media (prefers-reduced-motion:reduce){*{scroll-behavior:auto !important}}