/* =========================================================
   Jack Zhang — single page site
   Palette: ink base, one signal accent, one alert accent.
   ========================================================= */

:root {
  --ink:        #090c10;
  --ink-2:      #0f141a;
  --ink-3:      #161c24;
  --line:       rgba(255, 255, 255, .10);
  --line-2:     rgba(255, 255, 255, .06);

  --text:       #e9ecef;
  --muted:      #949ea8;
  --faint:      #6b757f;

  --paper:      #f4f2ee;
  --paper-2:    #eae7e1;
  --paper-line: rgba(10, 14, 18, .12);
  --paper-text: #14181d;
  --paper-muted:#5d666f;

  --signal:     #63d6c4;
  --signal-dim: rgba(99, 214, 196, .16);
  --alert:      #e4572e;

  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue",
          "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas,
          "Liberation Mono", monospace;

  --pad: clamp(1.25rem, 5vw, 5.5rem);
  --maxw: 1180px;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 5.5rem;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--ink);
  color: var(--text);
  font-family: var(--sans);
  font-size: clamp(1rem, .96rem + .2vw, 1.075rem);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img, video { display: block; max-width: 100%; }
img { height: auto; }

h1, h2, h3 {
  margin: 0;
  font-weight: 620;
  line-height: 1.1;
  letter-spacing: -.022em;
  text-wrap: balance;
}

p { margin: 0 0 1.1em; }
p:last-child { margin-bottom: 0; }

a { color: inherit; }

:focus-visible {
  outline: 2px solid var(--signal);
  outline-offset: 3px;
  border-radius: 2px;
}

.skip {
  position: absolute;
  left: -9999px;
  top: 0;
  z-index: 200;
  padding: .7rem 1.1rem;
  background: var(--signal);
  color: #06201c;
  font: 600 .85rem/1 var(--mono);
  text-decoration: none;
}
.skip:focus { left: 1rem; top: 1rem; }

/* ---------- shared ---------- */

.wrap {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: var(--pad);
}
.wrap--narrow { max-width: 820px; }

.kicker {
  margin: 0 0 1.35rem;
  font: 500 .72rem/1 var(--mono);
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--signal);
}
.kicker--light { color: rgba(255, 255, 255, .8); }

.lede {
  max-width: 62ch;
  margin: 1.6rem 0 0;
  color: var(--muted);
  font-size: 1.06em;
}

.sec { padding-block: clamp(4.5rem, 11vw, 9rem); }
.sec--tight { padding-block: clamp(3.5rem, 7vw, 5.5rem); }
.sec--dark  { background: var(--ink); }
.sec--light {
  background: var(--paper);
  color: var(--paper-text);
}
.sec--light .kicker { color: #1c7e72; }
.sec--light .lede { color: var(--paper-muted); }

.sechead { max-width: 68ch; margin-bottom: clamp(2.75rem, 6vw, 4.75rem); }
.sechead h2 {
  font-size: clamp(1.85rem, 1.15rem + 2.7vw, 3.1rem);
}

/* ---------- nav ---------- */

.nav {
  position: fixed;
  inset: 0 0 auto;
  z-index: 100;
  border-bottom: 1px solid transparent;
  transition: background .35s ease, border-color .35s ease,
              backdrop-filter .35s ease;
}
.nav.is-stuck {
  background: rgba(9, 12, 16, .82);
  backdrop-filter: saturate(150%) blur(14px);
  -webkit-backdrop-filter: saturate(150%) blur(14px);
  border-bottom-color: var(--line);
}
.nav__in {
  max-width: var(--maxw);
  margin-inline: auto;
  padding: .85rem var(--pad);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
}
.nav__id {
  display: inline-flex;
  align-items: center;
  gap: .55rem;
  font: 600 .82rem/1 var(--mono);
  letter-spacing: .06em;
  text-decoration: none;
}
.nav__dot {
  width: 7px; height: 7px;
  border-radius: 50%;
  background: var(--signal);
  box-shadow: 0 0 0 0 var(--signal-dim);
  animation: pulse 2.8s ease-out infinite;
}
@keyframes pulse {
  0%   { box-shadow: 0 0 0 0 rgba(99, 214, 196, .5); }
  70%  { box-shadow: 0 0 0 9px rgba(99, 214, 196, 0); }
  100% { box-shadow: 0 0 0 0 rgba(99, 214, 196, 0); }
}
.nav__links {
  display: flex;
  flex-wrap: nowrap;
  gap: clamp(.9rem, 2vw, 1.9rem);
  font: 500 .76rem/1 var(--mono);
  letter-spacing: .04em;
}
.nav__links a {
  color: var(--muted);
  text-decoration: none;
  padding-block: .35rem;
  border-bottom: 1px solid transparent;
  transition: color .2s ease, border-color .2s ease;
}
.nav__links a:hover { color: var(--text); border-bottom-color: var(--signal); }

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

.hero {
  position: relative;
  min-height: 100svh;
  display: flex;
  align-items: flex-end;
  overflow: hidden;
  isolation: isolate;
}
.hero__bg { position: absolute; inset: 0; z-index: -2; }
.hero__bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: 50% 42%;
  animation: drift 26s ease-in-out infinite alternate;
}
@keyframes drift {
  from { transform: scale(1.06) translate3d(0, 0, 0); }
  to   { transform: scale(1.16) translate3d(-1.4%, -1.2%, 0); }
}
.hero__scrim {
  position: absolute;
  inset: 0;
  z-index: -1;
  background:
    linear-gradient(180deg, rgba(6, 9, 12, .72) 0%, rgba(6, 9, 12, .18) 30%,
                    rgba(6, 9, 12, .70) 64%, rgba(6, 9, 12, .97) 100%),
    linear-gradient(96deg, rgba(6, 9, 12, .95) 0%, rgba(6, 9, 12, .82) 26%,
                    rgba(6, 9, 12, .34) 52%, rgba(6, 9, 12, .06) 78%);
}

.hero__in {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding: 0 var(--pad) clamp(4.5rem, 9vw, 7rem);
}
.hero__name {
  font-size: clamp(2.5rem, 1.3rem + 5.6vw, 5.1rem);
  letter-spacing: -.035em;
  text-shadow: 0 2px 40px rgba(0, 0, 0, .5);
}
.hero__concept {
  margin: .5rem 0 0;
  font: 500 clamp(.92rem, .85rem + .35vw, 1.1rem)/1.4 var(--mono);
  letter-spacing: .3em;
  text-transform: uppercase;
  color: var(--signal);
}
.hero__lede {
  max-width: 40ch;
  margin: 1.9rem 0 0;
  font-size: clamp(1.06rem, .98rem + .45vw, 1.32rem);
  line-height: 1.5;
  color: rgba(255, 255, 255, .93);
  text-shadow: 0 1px 24px rgba(0, 0, 0, .6);
}
.hero__context {
  margin: 1.6rem 0 0;
  padding-top: 1.35rem;
  border-top: 1px solid rgba(255, 255, 255, .16);
  max-width: 46ch;
  font-size: .93rem;
  color: rgba(255, 255, 255, .62);
}

.hero__scroll {
  position: absolute;
  right: var(--pad);
  bottom: clamp(1.5rem, 4vw, 2.6rem);
  display: inline-flex;
  align-items: center;
  gap: .6rem;
  font: 500 .74rem/1.3 var(--mono);
  letter-spacing: .05em;
  color: rgba(255, 255, 255, .55);
  text-decoration: none;
  max-width: 24ch;
  text-align: right;
  transition: color .25s ease;
}
.hero__scroll svg {
  width: 17px; height: 17px;
  flex: none;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.7;
  stroke-linecap: round;
  stroke-linejoin: round;
  animation: nudge 2.6s ease-in-out infinite;
}
@keyframes nudge {
  0%, 100% { transform: translateY(0); }
  50%      { transform: translateY(4px); }
}
.hero__scroll:hover { color: #fff; }

/* ---------- media blocks ---------- */

.shot { margin: 0; }

/* Images and video keep their intrinsic ratio: nothing is cropped or stretched. */
.shot img,
.shot video {
  width: 100%;
  height: auto;
  object-fit: contain;
  border-radius: 4px;
  background: var(--ink-3);
  border: 1px solid var(--line-2);
}
.sec--light .shot img { border-color: var(--paper-line); background: #fff; }
.shot figcaption {
  margin-top: .7rem;
  font: 400 .78rem/1.5 var(--mono);
  color: var(--faint);
}
.sec--light .shot figcaption { color: var(--paper-muted); }

/* Framed variants letterbox the source inside a fixed box so rows stay aligned. */
.shot--frame img {
  aspect-ratio: 4 / 3;
  object-fit: contain;
  background: #fff;
  padding: .5rem;
}
.sec--dark .shot--frame img { border-color: var(--line); }

.shot--frame-code img {
  aspect-ratio: 3 / 2;
  object-fit: contain;
  background: #0b0f14;
  padding: 0;
}

/* Portrait clip: cap the width so its 9:16 height stays near the landscape one. */
.shot--portrait video {
  max-width: 14rem;
  margin-inline: auto;
  background: #000;
}

.shot--doc {
  max-width: 40rem;
  margin-inline: auto;
}
/* Tall multi-panel figure: cap it so the row does not outrun its text column. */
.shot--tallfig { max-width: 27rem; }
.shot--doc img {
  object-fit: contain;
  background: #fff;
  padding: clamp(1.1rem, 3vw, 2rem) clamp(1rem, 2.5vw, 1.75rem);
}

/* custom play/pause, keeps the native control bar off the design */
.vframe {
  position: relative;
  overflow: hidden;
  border-radius: 4px;
}
.vbtn {
  position: absolute;
  right: .55rem;
  bottom: .55rem;
  z-index: 2;
  display: inline-flex;
  align-items: center;
  gap: .45rem;
  padding: .42rem .7rem;
  border: 1px solid rgba(255, 255, 255, .22);
  border-radius: 100px;
  background: rgba(8, 11, 15, .62);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  color: #fff;
  font: 500 .7rem/1 var(--mono);
  letter-spacing: .05em;
  cursor: pointer;
  transition: background .2s ease, border-color .2s ease;
}
.vbtn:hover { background: rgba(8, 11, 15, .85); border-color: rgba(255, 255, 255, .4); }
.vbtn svg {
  width: 11px; height: 11px;
  fill: currentColor;
  stroke: none;
}
.vbtn .i-play { display: none; }
.vbtn[data-state="paused"] .i-play { display: block; }
.vbtn[data-state="paused"] .i-pause { display: none; }

/* ---------- case ---------- */

.case {
  padding-top: clamp(2.5rem, 5vw, 3.75rem);
  margin-top: clamp(2.5rem, 5vw, 3.75rem);
  border-top: 1px solid var(--line);
}
.sec--light .case { border-top-color: var(--paper-line); }

.case__head { margin-bottom: 1.75rem; }
.case__head h3 {
  font-size: clamp(1.3rem, 1.05rem + 1.1vw, 1.85rem);
}
.case__meta {
  margin: .6rem 0 0;
  font: 500 .74rem/1.4 var(--mono);
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--signal);
}
.sec--light .case__meta { color: #1c7e72; }

.case__body { max-width: 64ch; color: var(--muted); }
.sec--light .case__body { color: var(--paper-muted); }
.case__body--aside {
  padding-left: 1.15rem;
  border-left: 2px solid var(--alert);
  font-style: italic;
}

.case .shot,
.case .grid,
.case .flow,
.case .stats,
.case .stats,
.case .chainlist { margin-top: 2rem; }

/* ---------- grids ---------- */

.grid { display: grid; gap: clamp(1.1rem, 2.4vw, 1.9rem); }

.grid--split {
  grid-template-columns: 1.05fr 1fr;
  align-items: start;
}
.grid--split .stack {
  display: grid;
  gap: clamp(1.1rem, 2.4vw, 1.9rem);
}

.grid--media {
  grid-template-columns: 1.45fr .75fr;
  grid-template-areas:
    "landscape portrait"
    "chain      chain";
  align-items: start;
}
.grid--media .shot:nth-child(1) { grid-area: landscape; }
.grid--media .shot:nth-child(2) { grid-area: portrait; }
.grid--media .chainlist       { grid-area: chain; }

.grid--figure {
  grid-template-columns: 1.15fr 1fr;
  align-items: start;
}
.grid--figure .shot img { background: #fff; }
.grid--figure .stack {
  display: grid;
  gap: clamp(1.1rem, 2.4vw, 1.9rem);
}

.grid--certs {
  grid-template-columns: .85fr 1fr;
  gap: clamp(1.1rem, 2.4vw, 1.9rem);
  align-items: start;
}
.grid--certs .shot img { background: #fff; }
.grid--certs .stack {
  display: grid;
  gap: clamp(1.1rem, 2.4vw, 1.9rem);
}

/* ---------- flow ---------- */

.flow {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: .55rem;
}
.flow li {
  display: flex;
  align-items: baseline;
  gap: .9rem;
  padding: .78rem 1.05rem;
  border: 1px solid var(--line);
  border-left: 2px solid var(--signal);
  border-radius: 3px;
  background: linear-gradient(90deg, var(--signal-dim), transparent 55%);
}
.flow__k {
  font: 600 .8rem/1.3 var(--mono);
  letter-spacing: .05em;
  color: var(--signal);
}
.flow__v {
  font-size: .87rem;
  color: var(--muted);
  margin-left: auto;
  text-align: right;
}
.flow--light li {
  border-color: var(--paper-line);
  border-left-color: #1c7e72;
  background: linear-gradient(90deg, rgba(28, 126, 114, .09), transparent 55%);
}
.flow--light .flow__k { color: #14655c; }
.flow--light .flow__v { color: var(--paper-muted); }

/* horizontal variant: three short steps read better as a row than as stacked bars */
.flow--row {
  grid-template-columns: repeat(auto-fit, minmax(13rem, 1fr));
  gap: .7rem;
}
.flow--row li {
  flex-direction: column;
  align-items: flex-start;
  gap: .3rem;
  padding: .95rem 1.1rem;
}
.flow--row .flow__v { margin-left: 0; text-align: left; }

.chainlist {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: .5rem;
  align-content: start;
}
.chainlist li {
  padding: .42rem .9rem;
  border: 1px solid var(--line);
  border-radius: 100px;
  font: 500 .76rem/1 var(--mono);
  letter-spacing: .06em;
  color: var(--muted);
}

/* ---------- outreach ---------- */
/* The point of this block is that the device left the workbench, so it gets a
   lighter treatment than the dark prototyping sections. */

.outreach {
  margin-top: clamp(2.5rem, 5vw, 3.5rem);
  padding: clamp(1.4rem, 3vw, 2.1rem);
  border: 1px solid var(--line);
  border-radius: 4px;
  background: var(--ink-2);
}
.outreach__k {
  margin: 0 0 .85rem;
  font: 500 .72rem/1 var(--mono);
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--signal);
}
.outreach__t {
  max-width: 56ch;
  margin: 0;
  font-size: 1.04rem;
  line-height: 1.55;
  color: var(--text);
}
.outreach .grid--outreach {
  margin-top: 1.6rem;
  grid-template-columns: 1.25fr 1fr;
  align-items: start;
}
.outreach .grid--outreach .shot:first-child img { background: #14181d; }

.note {
  max-width: 44ch;
  font-size: .93rem;
  color: var(--muted);
}
.sec--light .note { color: var(--paper-muted); }

/* ---------- stats ---------- */

.stats {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--paper-line);
  border: 1px solid var(--paper-line);
}
.stats li {
  background: var(--paper);
  padding: clamp(1.1rem, 2.6vw, 1.9rem);
}
.stat__n {
  display: block;
  font: 600 clamp(1.6rem, 1.1rem + 1.9vw, 2.45rem)/1 var(--sans);
  letter-spacing: -.03em;
  font-variant-numeric: tabular-nums;
  color: var(--paper-text);
}
.stat__u {
  font-size: .48em;
  font-weight: 500;
  letter-spacing: .02em;
  color: #1c7e72;
}
.stat__l {
  display: block;
  margin-top: .7rem;
  font-size: .84rem;
  line-height: 1.45;
  color: var(--paper-muted);
}

/* ---------- layers ---------- */

.layers { position: relative; }

.layer {
  display: grid;
  grid-template-columns: 4rem minmax(0, 1fr) minmax(0, 19rem);
  gap: clamp(1rem, 2.5vw, 2rem);
  align-items: center;
  padding-block: clamp(1.5rem, 3vw, 2.35rem);
  border-top: 1px solid var(--line-2);
  position: relative;
}
.layers .layer:first-child { border-top: 0; padding-top: 0; }

.layer__n {
  margin: 0;
  align-self: start;
  padding-top: .35rem;
  font: 500 .95rem/1 var(--mono);
  color: var(--signal);
  font-variant-numeric: tabular-nums;
}
.layer__c h3 {
  font-size: clamp(1.15rem, 1rem + .7vw, 1.5rem);
  margin-bottom: .7rem;
}
.layer__c p {
  max-width: 52ch;
  font-size: .95rem;
  color: var(--muted);
  margin: 0;
}
.layer__fig img { aspect-ratio: 4 / 3; object-fit: contain; background: #fff; }
.layer__fig--code img {
  aspect-ratio: 3 / 2;
  object-fit: contain;
  background: #0b0f14;
}

/* ---------- pull quote ---------- */

.pull {
  margin-top: clamp(2.5rem, 5vw, 3.75rem);
  padding: clamp(1.4rem, 3vw, 2.1rem);
  border: 1px solid var(--line);
  border-radius: 4px;
  background:
    radial-gradient(120% 140% at 0% 0%, var(--signal-dim), transparent 60%),
    var(--ink-2);
}
.pull__k {
  margin: 0 0 .85rem;
  font: 500 .72rem/1 var(--mono);
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--signal);
}
.pull p:last-child {
  max-width: 70ch;
  font-size: .98rem;
  color: var(--muted);
  margin: 0;
}

/* ---------- recognition ---------- */

.awards { display: grid; gap: clamp(1.75rem, 4vw, 2.75rem); }

.award {
  display: grid;
  grid-template-columns: 6rem minmax(0, 1fr);
  gap: clamp(1rem, 3vw, 2.5rem);
  padding-top: 1.5rem;
  border-top: 1px solid var(--line);
}
.award__y {
  margin: 0;
  font: 500 1.15rem/1 var(--mono);
  letter-spacing: .04em;
  color: var(--signal);
  font-variant-numeric: tabular-nums;
}
.award ul {
  list-style: none;
  margin: 0;
  padding: 0;
  columns: 2;
  column-gap: clamp(1.5rem, 4vw, 3rem);
}
.award li {
  break-inside: avoid;
  padding: .3rem 0 .3rem 1rem;
  position: relative;
  font-size: .92rem;
  line-height: 1.5;
  color: var(--muted);
}
.award li::before {
  content: "";
  position: absolute;
  left: 0; top: .78em;
  width: 4px; height: 1px;
  background: var(--faint);
}

/* ---------- closing ---------- */

.sec--close {
  background: var(--ink-2);
  border-top: 1px solid var(--line);
}
.closing {
  max-width: 24ch;
  margin: 0 0 clamp(2.25rem, 5vw, 3.25rem);
  font-size: clamp(1.5rem, 1.05rem + 2.1vw, 2.6rem);
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -.025em;
  text-wrap: balance;
}
.shot--close img { aspect-ratio: 16 / 9; }

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

.foot {
  padding-block: 2.5rem 3rem;
  border-top: 1px solid var(--line);
  font: 400 .8rem/1.6 var(--mono);
  color: var(--faint);
}
.foot p { margin: 0; }
.foot__n { margin-top: .35rem !important; color: var(--faint); }

/* ---------- reveal ---------- */

.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity .7s cubic-bezier(.22, .7, .3, 1),
              transform .7s cubic-bezier(.22, .7, .3, 1);
}
.reveal.in { opacity: 1; transform: none; }

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

@media (max-width: 900px) {
  .grid--split,
  .grid--figure,
  .grid--certs,
  .grid--media {
    grid-template-columns: 1fr;
    grid-template-areas: none;
  }
  .grid--media .shot:nth-child(1),
  .grid--media .shot:nth-child(2),
  .grid--media .chainlist { grid-area: auto; }
  .outreach .grid--outreach { grid-template-columns: 1fr; }
  .shot--portrait video { max-width: 22rem; }
  .stats { grid-template-columns: 1fr; }
  .layer {
    grid-template-columns: 2.4rem minmax(0, 1fr);
    grid-template-areas:
      "n  c"
      "f  f";
    row-gap: 1.1rem;
  }
  .layer__n { grid-area: n; }
  .layer__c { grid-area: c; }
  .layer__fig { grid-area: f; }
  .layer__fig img { aspect-ratio: 16 / 10; }
}

@media (max-width: 720px) {
  html { scroll-padding-top: 4.25rem; }
  .nav__links {
    gap: 1rem;
    font-size: .72rem;
    overflow-x: auto;
    scrollbar-width: none;
    -webkit-overflow-scrolling: touch;
    /* fade the cut-off edge so it reads as scrollable */
    mask-image: linear-gradient(90deg, #000 82%, transparent);
    -webkit-mask-image: linear-gradient(90deg, #000 82%, transparent);
  }
  .nav__links a { white-space: nowrap; }
  .nav__links::-webkit-scrollbar { display: none; }
  .nav__in { padding-block: .7rem; }
  .award { grid-template-columns: 1fr; gap: .9rem; }
  .award ul { columns: 1; }
  .flow--row { grid-template-columns: 1fr; }

  /* stack the hero so the scroll hint sits below the copy, not beside it */
  .hero {
    flex-direction: column;
    justify-content: flex-end;
    min-height: auto;
    padding-top: 52svh;
  }
  .hero__in { padding-bottom: 0; }
  .hero__scroll {
    position: static;
    max-width: none;
    text-align: left;
    width: 100%;
    margin: 2.25rem auto 0;
    padding: 0 var(--pad) 2.75rem;
  }
  .hero__scroll svg { animation: none; }
}

@media (max-width: 460px) {
  .nav__id span:last-child { display: none; }
  .sec { padding-block: 3.5rem; }
}

/* ---------- motion / contrast ---------- */

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }
  .reveal { opacity: 1; transform: none; }
}

@media print {
  .nav, .hero__scroll, .reveal { display: none; }
  .reveal { opacity: 1; transform: none; }
  body { background: #fff; color: #000; }
}