/* ============================================================
   Zubair Ahmed — case study pages
   Light theme, matched to the main portfolio layout.
   ============================================================ */

:root {
  --paper:   #F7F9F8;
  --paper-2: #FFFFFF;
  --ink:     #0B2129;
  --body-c:  #40595F;
  --muted:   #7E959B;
  --line:    #DFE6E4;
  --accent:  #D62B60;
  --teal:    #0F6E7B;
  --gold:    #A9761A;

  --display: "Archivo", "Helvetica Neue", sans-serif;
  --body:    "Karla", system-ui, sans-serif;
  --mono:    "IBM Plex Mono", ui-monospace, monospace;

  --gut:  clamp(20px, 5vw, 56px);
  --maxw: 1140px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 80px; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--body-c);
  font-family: var(--body);
  font-size: 17px;
  line-height: 1.68;
  -webkit-font-smoothing: antialiased;
}

/* height:auto keeps the intrinsic ratio when max-width shrinks the image —
   without it, the width/height attributes stretch the picture */
img { max-width: 100%; height: auto; display: block; }
a { color: inherit; }
::selection { background: var(--accent); color: #fff; }

.wrap { max-width: var(--maxw); margin: 0 auto; padding-inline: var(--gut); }

h1, h2, h3, h4 {
  font-family: var(--display);
  font-variation-settings: "wdth" 110;
  color: var(--ink);
  line-height: 1.12;
  margin: 0;
}

.eyebrow {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 14px;
}

.lede { font-size: 18px; color: var(--body-c); max-width: 66ch; margin: 0; }
.section { padding: clamp(50px, 7vw, 84px) 0; }

/* ---------- top bar ---------- */

.bar {
  position: sticky; top: 0; z-index: 50;
  background: rgba(247, 249, 248, .93);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
}
.bar-in {
  max-width: var(--maxw); margin: 0 auto; padding: 0 var(--gut);
  height: 68px; display: flex; align-items: center; justify-content: space-between; gap: 20px;
}
.mark {
  font-family: var(--display); font-variation-settings: "wdth" 122;
  font-weight: 800; font-size: 15px; letter-spacing: .05em;
  color: var(--ink); text-decoration: none; white-space: nowrap;
}
.mark span { color: var(--accent); }
.coords { font-family: var(--mono); font-size: 10.5px; letter-spacing: .12em; text-transform: uppercase; color: var(--muted); }
.nav { display: flex; gap: 26px; align-items: center; }
.nav a {
  font-family: var(--mono); font-size: 12px; letter-spacing: .1em;
  text-transform: uppercase; text-decoration: none; color: var(--muted);
  padding: 4px 0; border-bottom: 1px solid transparent;
}
.nav a:hover, .nav a:focus-visible { color: var(--ink); border-bottom-color: var(--accent); }

/* ---------- hero ---------- */

.p-hero { padding: clamp(40px, 6vw, 68px) 0 clamp(34px, 4vw, 52px); border-bottom: 1px solid var(--line); }
.back {
  font-family: var(--mono); font-size: 11.5px; letter-spacing: .1em;
  text-transform: uppercase; color: var(--muted); text-decoration: none;
  display: inline-block; margin-bottom: 24px;
}
.back::before { content: "← "; }
.back:hover, .back:focus-visible { color: var(--accent); }

.p-hero h1 {
  font-size: clamp(32px, 5.4vw, 58px);
  font-variation-settings: "wdth" 114;
  font-weight: 800; letter-spacing: -.028em;
  margin-bottom: 16px; max-width: 22ch;
}

/* capture / metadata strip */
.capture {
  margin: 34px 0 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}
.capture div { background: var(--paper-2); padding: 16px 18px; }
.capture dt {
  font-family: var(--mono); font-size: 10px; letter-spacing: .14em;
  text-transform: uppercase; color: var(--muted); margin-bottom: 7px;
}
.capture dd { margin: 0; font-family: var(--mono); font-size: 12.5px; color: var(--ink); line-height: 1.5; }

/* ---------- prose ---------- */

.prose { max-width: 74ch; }
.prose h2 {
  font-size: clamp(22px, 3vw, 30px); font-weight: 700;
  letter-spacing: -.015em; margin: 0 0 16px;
}
.prose h3 {
  font-size: 18px; font-variation-settings: "wdth" 104; font-weight: 700;
  margin: 34px 0 10px; color: var(--teal);
}
.prose p { margin: 0 0 16px; }
.prose ul { padding-left: 20px; margin: 0 0 18px; }
.prose li { margin-bottom: 8px; }
.prose li::marker { color: var(--accent); }
.prose strong { color: var(--ink); font-weight: 700; }
.prose a { color: var(--accent); }
.prose em { color: var(--ink); }

/* ---------- figure plates ---------- */

.plate { margin: 34px 0; }
.plate-mount {
  background: var(--paper-2);
  border: 1px solid var(--line);
  border-radius: 2px;
  padding: 16px;
}
.plate-mount img { margin: 0 auto; }
.plate figcaption {
  font-family: var(--mono); font-size: 11px; line-height: 1.6;
  color: var(--muted); margin-top: 11px;
  display: grid; grid-template-columns: auto 1fr; gap: 12px;
}
.plate figcaption b {
  color: var(--accent); font-weight: 500; letter-spacing: .12em;
  text-transform: uppercase; white-space: nowrap;
}
.plate-pair { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.plate-pair img { width: 100%; }
/* portrait diagrams — capped so one flowchart does not run for three screens,
   while staying wide enough that its labels are still readable */
.plate-tall .plate-mount img { max-height: 1100px; width: auto; }

/* ---------- data tables ---------- */

.dtable {
  width: 100%; border-collapse: collapse;
  font-family: var(--mono); font-size: 12.5px; margin: 0 0 22px;
  background: var(--paper-2); border: 1px solid var(--line);
}
.dtable th, .dtable td { text-align: left; padding: 11px 14px; border-bottom: 1px solid var(--line); vertical-align: top; }
.dtable tr:last-child td { border-bottom: 0; }
.dtable th {
  font-size: 10px; letter-spacing: .14em; text-transform: uppercase;
  color: var(--muted); font-weight: 500; background: var(--paper);
}
.dtable td:first-child { color: var(--teal); white-space: nowrap; }
.dtable td:last-child { color: var(--body-c); font-family: var(--body); font-size: 15px; }
.dtable td.num { font-family: var(--mono); color: var(--ink); white-space: nowrap; }
.dtable .pass { color: #12764F; }
.dtable .fail { color: var(--accent); }

/* ---------- pipeline steps ---------- */

.flow { display: flex; flex-wrap: wrap; align-items: stretch; gap: 8px; margin: 22px 0 30px; }
.flow-step {
  flex: 1 1 150px;
  border: 1px solid var(--line);
  border-radius: 2px;
  padding: 14px 15px;
  background: var(--paper-2);
}
.flow-step em {
  display: block; font-family: var(--mono); font-style: normal;
  font-size: 9.5px; letter-spacing: .14em; text-transform: uppercase;
  color: var(--accent); margin-bottom: 7px;
}
.flow-step span { font-size: 14px; color: var(--body-c); line-height: 1.4; }

/* ---------- callout ---------- */

.callout {
  border-left: 3px solid var(--accent);
  background: var(--paper-2);
  border-top: 1px solid var(--line);
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  padding: 20px 24px;
  margin: 28px 0;
  border-radius: 0 2px 2px 0;
}
.callout .k {
  font-family: var(--mono); font-size: 10px; letter-spacing: .14em;
  text-transform: uppercase; color: var(--muted); display: block; margin-bottom: 8px;
}
.callout .formula { font-family: var(--mono); font-size: clamp(15px, 2.2vw, 20px); color: var(--teal); }
.callout p { margin: 10px 0 0; font-size: 15px; }
.callout p:first-of-type { margin-top: 0; }

/* ---------- next / prev ---------- */

.p-next {
  display: flex; justify-content: space-between; gap: 20px; flex-wrap: wrap;
  padding: 30px 0 56px; border-top: 1px solid var(--line);
}
.p-next a {
  font-family: var(--mono); font-size: 12px; letter-spacing: .08em;
  text-transform: uppercase; text-decoration: none; color: var(--muted);
}
.p-next a:hover, .p-next a:focus-visible { color: var(--accent); }

/* ---------- footer ---------- */

.foot {
  border-top: 1px solid var(--line); background: var(--paper-2);
  padding: 26px 0 34px; margin-top: 0;
  display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap;
  font-family: var(--mono); font-size: 11.5px; color: var(--muted);
  max-width: var(--maxw); margin-inline: auto;
}

/* ---------- a11y + motion ---------- */

:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }
.skip {
  position: absolute; left: -9999px;
  background: var(--accent); color: #fff; padding: 10px 16px; z-index: 100;
  font-family: var(--mono); font-size: 12px; text-decoration: none;
}
.skip:focus { left: 8px; top: 8px; }

.rv { opacity: 0; transform: translateY(14px); transition: opacity .55s ease, transform .55s ease; }
.rv.in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .rv { opacity: 1; transform: none; transition: none; }
  * { transition-duration: .001ms !important; }
}

/* ---------- responsive ---------- */

@media (max-width: 760px) {
  .coords { display: none; }
  .plate figcaption { grid-template-columns: 1fr; gap: 4px; }
  .plate-pair { grid-template-columns: 1fr; }
}
@media (max-width: 560px) {
  body { font-size: 16px; }
  /* stack rather than hide — see the matching rule in alt.css */
  .bar-in { height: auto; flex-direction: column; gap: 9px; padding-block: 11px; }
  .nav { gap: 18px; flex-wrap: wrap; justify-content: center; }
  .nav a { font-size: 11px; letter-spacing: .06em; }
  html { scroll-padding-top: 108px; }
  .dtable { font-size: 11.5px; }
  .dtable th, .dtable td { padding: 9px 10px; }
}