/* Muhammad Shah — portfolio, 2026 redesign.
   Paper, ink, one vermilion. Bricolage Grotesque / Source Serif 4 / JetBrains Mono. */

:root {
  --paper: #f4f0e6;
  --paper-glass: rgba(244, 240, 230, 0.86);   /* --paper at 86%, for the sticky bar */
  --paper-3: #ddd6c4;
  --ledger: rgba(28, 29, 35, 0.055);           /* --ink at 5.5%, the ruled-paper lines */
  --ink-shadow: rgba(28, 29, 35, 0.45);        /* --ink at 45%, the spec-sheet shadow */
  --card: rgba(255, 255, 255, 0.5);
  --ink: #1c1d23;
  --ink-2: #4a4d58;
  --ink-3: #7b7f8a;
  --rule: #d5cebd;
  --accent: #de4a1f;
  --accent-glow: rgba(222, 74, 31, 0.45);      /* --accent at 45%, start of the pulse ring */
  --accent-glow-0: rgba(222, 74, 31, 0);       /* --accent at 0%, end of the pulse ring */
  --accent-deep: #b53a13;
  --night: #15161b;
  --night-rule: #33363e;
  --on-night: #efe9da;
  --on-night-2: #aeaa9e;
  --on-night-3: #7d7a70;
  --display: "Bricolage Grotesque", "Helvetica Neue", Arial, sans-serif;
  --serif: "Source Serif 4", Georgia, "Times New Roman", serif;
  --mono: "JetBrains Mono", ui-monospace, "Cascadia Mono", Consolas, Menlo, monospace;
  --max: 1240px;
  --gutter: clamp(20px, 4.5vw, 64px);
  --ease: cubic-bezier(0.2, 0.7, 0.2, 1);
}

*,
*::before,
*::after { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  background: var(--paper);
}

body {
  margin: 0;
  background-color: var(--paper);
  background-image: linear-gradient(var(--ledger) 1px, transparent 1px);
  background-size: 100% 32px;
  color: var(--ink);
  font-family: var(--serif);
  font-size: 17px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

::selection { background: var(--accent); color: #fff; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }

a { color: var(--accent-deep); }
a:hover { color: var(--accent); }

.skip {
  position: absolute;
  left: 16px;
  top: -60px;
  z-index: 100;
  background: var(--ink);
  color: var(--paper);
  padding: 12px 16px;
  font: 500 13px/1 var(--mono);
  text-decoration: none;
}
.skip:focus { top: 12px; }

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

.topbar {
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--paper-glass);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--rule);
}
.topbar__in {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 var(--gutter);
  height: 58px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  font: 500 12.5px/1 var(--mono);
  letter-spacing: 0.05em;
  text-transform: uppercase;
}
.brand {
  color: var(--ink);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 10px;
  white-space: nowrap;
}
.brand:hover { color: var(--ink); }
.brand__mark { width: 10px; height: 10px; background: var(--accent); flex: none; }
.nav { display: flex; gap: clamp(14px, 2.2vw, 28px); }
.nav a {
  color: var(--ink-2);
  text-decoration: none;
  padding: 22px 0;
  position: relative;
}
.nav a::after {
  content: "";
  position: absolute;
  left: 0;
  right: 100%;
  bottom: 17px;
  height: 2px;
  background: var(--accent);
  transition: right 0.3s var(--ease);
}
.nav a:hover { color: var(--ink); }
.nav a:hover::after,
.nav a:focus-visible::after { right: 0; }
.clock {
  color: var(--ink-3);
  display: flex;
  align-items: center;
  gap: 10px;
  white-space: nowrap;
}
.clock [data-clock] { color: var(--ink); }

.pulse {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent);
  flex: none;
  animation: pulse 2.2s infinite;
}
@keyframes pulse {
  0% { box-shadow: 0 0 0 0 var(--accent-glow); }
  70% { box-shadow: 0 0 0 10px var(--accent-glow-0); }
  100% { box-shadow: 0 0 0 0 var(--accent-glow-0); }
}

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

.hero { padding: clamp(56px, 9vw, 124px) 0 clamp(48px, 7vw, 96px); }
.hero__in {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 var(--gutter);
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(300px, 380px);
  gap: clamp(32px, 5vw, 80px);
  align-items: end;
}
.eyebrow {
  font: 500 12.5px/1.4 var(--mono);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-2);
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 28px;
}
.h1 {
  font-family: var(--display);
  font-weight: 800;
  font-size: clamp(44px, 7.4vw, 108px);
  line-height: 0.96;
  letter-spacing: -0.035em;
  font-variation-settings: "opsz" 96, "wdth" 90;
  margin: 0 0 32px;
  text-wrap: balance;
}
.h1 .w {
  display: inline-block;
  animation: rise 0.9s var(--ease) both;
  animation-delay: calc(var(--i, 0) * 55ms);
}
.h1 .u {
  background: linear-gradient(var(--accent), var(--accent)) no-repeat 0 92% / 100% 0.1em;
  -webkit-box-decoration-break: clone;
  box-decoration-break: clone;
  animation: draw 0.7s var(--ease) 0.75s both;
}
@keyframes rise {
  from { opacity: 0; transform: translateY(0.35em); }
}
@keyframes draw {
  from { background-size: 0 0.1em; }
}
.lede {
  font-size: clamp(17px, 1.5vw, 20px);
  line-height: 1.55;
  color: var(--ink-2);
  max-width: 60ch;
  margin: 0 0 36px;
}
.lede strong { color: var(--ink); font-weight: 600; }
.cta { display: flex; flex-wrap: wrap; gap: 12px; }
.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  height: 48px;
  padding: 0 20px;
  border: 1px solid var(--ink);
  color: var(--ink);
  text-decoration: none;
  font: 500 13px/1 var(--mono);
  letter-spacing: 0.05em;
  text-transform: uppercase;
  border-radius: 999px;
  transition: background 0.25s var(--ease), color 0.25s var(--ease), border-color 0.25s var(--ease);
}
.btn:hover { background: var(--ink); color: var(--paper); }
.btn--primary { background: var(--accent); border-color: var(--accent); color: #fff; }
.btn--primary:hover { background: var(--accent-deep); border-color: var(--accent-deep); color: #fff; }
.btn svg { width: 16px; height: 16px; }

.sheet {
  background: var(--night);
  color: var(--on-night);
  border-radius: 4px;
  padding: 22px 24px 20px;
  font: 400 13px/1.75 var(--mono);
  box-shadow: 0 30px 60px -30px var(--ink-shadow);
}
.sheet__head {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  color: var(--on-night-3);
  font-size: 11.5px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  border-bottom: 1px solid var(--night-rule);
  padding-bottom: 12px;
  margin-bottom: 12px;
}
.sheet__row {
  display: grid;
  grid-template-columns: 84px minmax(0, 1fr);
  gap: 12px;
  animation: rise 0.7s var(--ease) both;
  animation-delay: calc(0.35s + var(--i, 0) * 70ms);
}
.sheet__k { color: var(--on-night-3); }
.sheet__v { color: var(--on-night); overflow-wrap: anywhere; }
.dot {
  display: inline-block;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--accent);
  margin-right: 8px;
  vertical-align: 1px;
}
.sheet__cursor {
  display: inline-block;
  width: 8px;
  height: 14px;
  background: var(--accent);
  vertical-align: -2px;
  margin-left: 4px;
  animation: blink 1.1s steps(1) infinite;
}
@keyframes blink { 50% { opacity: 0; } }

/* ---------- sections ---------- */

.section { padding: clamp(56px, 8vw, 112px) 0; border-top: 1px solid var(--rule); }
.section__in { max-width: var(--max); margin: 0 auto; padding: 0 var(--gutter); }
.sec-head {
  display: grid;
  grid-template-columns: 72px minmax(0, 1fr) auto;
  gap: 16px 24px;
  align-items: baseline;
  margin: 0 0 clamp(28px, 4vw, 48px);
}
.sec-head__n {
  font: 500 13px/1 var(--mono);
  color: var(--accent-deep);
  letter-spacing: 0.06em;
}
.sec-head__n::before {
  content: "";
  display: inline-block;
  width: 8px;
  height: 8px;
  background: var(--accent);
  margin-right: 10px;
}
.sec-head h2 {
  margin: 0;
  font-family: var(--display);
  font-weight: 700;
  font-size: clamp(30px, 3.6vw, 48px);
  line-height: 1.02;
  letter-spacing: -0.025em;
  font-variation-settings: "opsz" 96, "wdth" 92;
  text-wrap: balance;
}
.sec-head__meta {
  font: 500 12.5px/1.4 var(--mono);
  color: var(--ink-3);
  letter-spacing: 0.05em;
  text-transform: uppercase;
  text-align: right;
  text-decoration: none;
}
a.sec-head__meta:hover { color: var(--accent-deep); }
.intro {
  font-size: clamp(17px, 1.35vw, 19.5px);
  color: var(--ink-2);
  max-width: 70ch;
  margin: 0 0 clamp(28px, 3.5vw, 44px);
}
.intro strong { color: var(--ink); font-weight: 600; }

/* ---------- cards ---------- */

.cards { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px; }
.card {
  border: 1px solid var(--rule);
  background: var(--card);
  padding: 26px 26px 22px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  border-radius: 3px;
  transition: border-color 0.3s var(--ease), background 0.3s var(--ease);
}
.card:hover { border-color: var(--ink); background: rgba(255, 255, 255, 0.72); }
.card__tag {
  font: 500 11.5px/1.4 var(--mono);
  color: var(--accent-deep);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.card h3 {
  margin: 0;
  font-family: var(--display);
  font-weight: 700;
  font-size: 24px;
  line-height: 1.12;
  letter-spacing: -0.02em;
  text-wrap: balance;
}
.card p { margin: 0; color: var(--ink-2); font-size: 16px; }
.card__foot {
  margin-top: auto;
  padding-top: 14px;
  border-top: 1px dashed var(--rule);
  font: 500 12px/1.5 var(--mono);
  color: var(--ink-3);
  letter-spacing: 0.04em;
}
.metric { display: flex; align-items: baseline; gap: 12px; }
.metric__n {
  font-family: var(--display);
  font-weight: 800;
  font-size: 40px;
  letter-spacing: -0.03em;
  line-height: 1;
  color: var(--ink);
  font-variation-settings: "opsz" 96, "wdth" 88;
  white-space: nowrap;
}
.metric__l {
  font: 500 11.5px/1.35 var(--mono);
  color: var(--ink-3);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}
.metrics { display: flex; gap: 28px; flex-wrap: wrap; }
.metrics .metric { flex-direction: column; gap: 6px; align-items: flex-start; }
.metrics .metric__n { font-size: 32px; color: var(--accent-deep); }

/* ---------- publication (night block) ---------- */

.night { background: var(--night); color: var(--on-night); border-top: 0; }
.night .sec-head h2 { color: var(--on-night); }
.night .sec-head__meta { color: var(--on-night-3); }
.night .sec-head__n { color: var(--accent); }
.paper-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.6fr) minmax(260px, 0.9fr);
  gap: clamp(32px, 5vw, 72px);
  align-items: start;
}
.paper__title {
  font-family: var(--display);
  font-weight: 700;
  font-size: clamp(26px, 2.8vw, 38px);
  line-height: 1.1;
  letter-spacing: -0.02em;
  margin: 0 0 18px;
  text-wrap: balance;
}
.paper__authors {
  font: 400 14px/1.6 var(--mono);
  color: var(--on-night-2);
  margin: 0 0 22px;
}
.paper__authors strong { color: var(--on-night); font-weight: 600; }
.paper__abs { color: var(--on-night-2); font-size: 17.5px; margin: 0 0 26px; }
.paper__abs strong { color: var(--on-night); font-weight: 600; }
.pipe {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
  font: 500 12.5px/1 var(--mono);
  color: var(--on-night-2);
  margin-top: clamp(28px, 4vw, 48px);
  padding-top: 26px;
  border-top: 1px solid var(--night-rule);
}
.pipe span { border: 1px solid var(--night-rule); padding: 11px 13px; border-radius: 999px; }
.pipe .pipe__label {
  border: 0;
  padding: 0;
  margin-right: 14px;
  color: var(--on-night-3);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.pipe i { color: var(--accent); font-style: normal; }
.bigstat { border-top: 1px solid var(--night-rule); padding: 22px 0; }
.bigstat:last-child { border-bottom: 1px solid var(--night-rule); }
.bigstat__n {
  font-family: var(--display);
  font-weight: 800;
  font-size: clamp(56px, 6vw, 88px);
  line-height: 0.9;
  letter-spacing: -0.04em;
  color: var(--on-night);
  font-variation-settings: "opsz" 96, "wdth" 85;
}
.bigstat__n em { color: var(--accent); font-style: normal; }
.bigstat__l {
  font: 500 12.5px/1.5 var(--mono);
  color: var(--on-night-2);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-top: 10px;
  max-width: 30ch;
}
.paper__note { font: 400 13px/1.6 var(--mono); color: var(--on-night-3); margin: 18px 0 0; }

/* ---------- timeline ---------- */

.trace {
  border: 1px solid var(--rule);
  border-radius: 3px;
  background: var(--card);
  padding: 22px 22px 18px;
  margin-bottom: clamp(28px, 4vw, 48px);
}
.trace__axis {
  display: grid;
  grid-template-columns: 150px minmax(0, 1fr);
  gap: 16px;
  font: 500 11.5px/1 var(--mono);
  color: var(--ink-3);
  letter-spacing: 0.05em;
  text-transform: uppercase;
  margin-bottom: 26px;
}
.trace__years { position: relative; height: 12px; }
.trace__years span { position: absolute; top: 0; }
.trace__body { display: grid; grid-template-columns: 150px minmax(0, 1fr); gap: 16px; }
.trace__labels { display: flex; flex-direction: column; }
.trace__label {
  height: 40px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  font: 500 12px/1.3 var(--mono);
  color: var(--ink-2);
}
.trace__label small { color: var(--ink-3); font-weight: 400; font-size: 11px; }
.trace__lanes { position: relative; }
.trace__lane {
  position: relative;
  height: 40px;
  background-image: repeating-linear-gradient(90deg, var(--rule) 0 1px, transparent 1px 16.6667%);
}
.bar {
  position: absolute;
  top: 11px;
  height: 18px;
  background: var(--ink-2);
  border-radius: 2px;
  transform-origin: left center;
}
.bar--edu { background: var(--paper-3); border: 1px solid var(--rule); }
.bar--now { background: var(--accent); }
.bar--now::after {
  content: "";
  position: absolute;
  right: -5px;
  top: 4px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--accent);
  animation: pulse 2.2s infinite;
}
.now-line {
  position: absolute;
  top: -22px;
  bottom: 0;
  border-left: 1px dashed var(--accent-deep);
}
.now-line span {
  position: absolute;
  bottom: -16px;
  right: 8px;
  font: 500 11px/1 var(--mono);
  color: var(--accent-deep);
  white-space: nowrap;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.tl { display: flex; flex-direction: column; }
.tl__item {
  display: grid;
  grid-template-columns: 190px minmax(0, 1fr);
  gap: 12px 32px;
  padding: 28px 0;
  border-top: 1px solid var(--rule);
}
.tl__item:last-child { border-bottom: 1px solid var(--rule); }
.tl__when {
  font: 500 12.5px/1.6 var(--mono);
  color: var(--accent-deep);
  letter-spacing: 0.05em;
  text-transform: uppercase;
}
.tl__when small { display: block; color: var(--ink-3); text-transform: none; letter-spacing: 0; font-size: 12px; }
.tl__role {
  margin: 0 0 8px;
  font-family: var(--display);
  font-weight: 700;
  font-size: 24px;
  letter-spacing: -0.02em;
  line-height: 1.1;
}
.tl__role span { color: var(--ink-2); font-weight: 500; }
.tl__body { color: var(--ink-2); margin: 0; font-size: 16.5px; }
.tl__body + .tl__body { margin-top: 8px; }
.tl__body strong { color: var(--ink); font-weight: 600; }

/* ---------- stack ---------- */

.stack {
  display: grid;
  grid-template-columns: 200px minmax(0, 1fr);
  gap: 0 32px;
  margin: 0;
  border-top: 1px solid var(--rule);
}
.stack dt {
  font: 500 12.5px/1.5 var(--mono);
  color: var(--accent-deep);
  letter-spacing: 0.05em;
  text-transform: uppercase;
  padding: 18px 0;
  border-bottom: 1px solid var(--rule);
}
.stack dd {
  margin: 0;
  padding: 16px 0;
  border-bottom: 1px solid var(--rule);
  font-size: 17px;
  color: var(--ink);
}

/* ---------- open source ---------- */

.repos { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 16px; }
.repo {
  border: 1px solid var(--rule);
  padding: 20px 20px 18px;
  text-decoration: none;
  color: inherit;
  display: flex;
  flex-direction: column;
  gap: 10px;
  border-radius: 3px;
  background: var(--card);
  transition: border-color 0.3s var(--ease), transform 0.4s var(--ease), background 0.3s var(--ease);
}
.repo:hover { border-color: var(--ink); transform: translateY(-2px); color: inherit; background: rgba(255, 255, 255, 0.72); }
.repo__name {
  font: 600 13.5px/1.3 var(--mono);
  color: var(--ink);
  display: flex;
  justify-content: space-between;
  gap: 10px;
}
.repo__name svg { width: 16px; height: 16px; flex: none; color: var(--ink-3); }
.repo:hover .repo__name svg { color: var(--accent); }
.repo p { margin: 0; color: var(--ink-2); font-size: 15.5px; }
.repo__meta {
  margin-top: auto;
  padding-top: 10px;
  font: 500 11.5px/1.4 var(--mono);
  color: var(--ink-3);
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

/* ---------- contact ---------- */

.contact .h2big {
  font-family: var(--display);
  font-weight: 800;
  font-size: clamp(36px, 5.6vw, 80px);
  line-height: 0.98;
  letter-spacing: -0.035em;
  margin: 0 0 36px;
  max-width: 18ch;
  font-variation-settings: "opsz" 96, "wdth" 90;
  text-wrap: balance;
}
.mail {
  display: inline-block;
  font-family: var(--display);
  font-weight: 600;
  font-size: clamp(22px, 3.4vw, 44px);
  letter-spacing: -0.02em;
  color: var(--ink);
  text-decoration: none;
  border-bottom: 3px solid var(--accent);
  line-height: 1.2;
  margin-bottom: 32px;
  overflow-wrap: anywhere;
}
.mail:hover { color: var(--accent-deep); }
.links {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 32px;
  font: 500 13px/1.4 var(--mono);
  letter-spacing: 0.04em;
}
.links a {
  color: var(--ink-2);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 9px;
  min-height: 44px;
}
.links a:hover { color: var(--accent-deep); }
.links svg { width: 18px; height: 18px; }
.where {
  margin: 22px 0 0;
  font: 400 12.5px/1.6 var(--mono);
  color: var(--ink-3);
  letter-spacing: 0.04em;
}

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

.foot { border-top: 1px solid var(--rule); padding: 26px 0 44px; font: 400 12px/1.7 var(--mono); color: var(--ink-3); }
.foot__in {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 var(--gutter);
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 8px 24px;
}
.foot a { color: var(--ink-2); text-decoration: none; }
.foot a:hover { color: var(--accent-deep); }

/* ---------- reveal & motion ---------- */

.reveal { transition: opacity 0.8s var(--ease), transform 0.8s var(--ease); }
/* The observer in site.js adds .in as each block scrolls into view; the delayed
   animation is a safety net so nothing stays hidden if the script never runs. */
html.js .reveal:not(.in) {
  opacity: 0;
  transform: translateY(16px);
  animation: reveal-anyway 0.8s var(--ease) 2.5s forwards;
}
@keyframes reveal-anyway {
  to { opacity: 1; transform: none; }
}
html.js .bar { transform: scaleX(0); transition: transform 1.1s var(--ease); transition-delay: calc(var(--d, 0) * 120ms); }
html.js .trace.in .bar { transform: scaleX(1); }

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after { animation: none !important; transition: none !important; }
  html { scroll-behavior: auto; }
  html.js .reveal:not(.in) { opacity: 1; transform: none; }
  html.js .bar { transform: none; }
}

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

@media (max-width: 980px) {
  .hero__in { grid-template-columns: 1fr; align-items: start; }
  .sheet { max-width: 520px; }
  .paper-grid { grid-template-columns: 1fr; }
  .repos { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .clock { display: none; }
}

@media (max-width: 720px) {
  body { font-size: 16px; }
  .nav a[data-mh] { display: none; }
  .cards,
  .repos { grid-template-columns: 1fr; }
  .sec-head { grid-template-columns: 1fr; gap: 10px; }
  .sec-head__meta { text-align: left; }
  .tl__item { grid-template-columns: 1fr; gap: 8px; padding: 22px 0; }
  .stack { grid-template-columns: 1fr; gap: 0; }
  .stack dt { padding: 16px 0 4px; border-bottom: 0; }
  .stack dd { padding: 0 0 16px; }
  .trace { padding: 18px 16px 22px; }
  .trace__axis,
  .trace__body { grid-template-columns: 1fr; gap: 0; }
  .trace__axis > span:first-child,
  .trace__labels { display: none; }
  .trace__lane { height: 30px; }
  .bar { top: 8px; height: 14px; }
  .bar--now::after { top: 2px; }
  .metrics { gap: 18px; }
  .card { padding: 22px 20px 18px; }
  .card h3 { font-size: 22px; }
}

@media (max-width: 420px) {
  .topbar__in { font-size: 11.5px; gap: 14px; }
  .nav { gap: 12px; }
  .btn { padding: 0 16px; }
}