/* ============================================================
   Carey Chou — Liquid Glass design system
   Creativity × Science × AI × Tech
   Shared by the homepage + art gallery + writing hub.
   ============================================================ */

:root {
  /* base surfaces */
  --bg-0: #05070f;
  --bg-1: #0a0e1c;
  --ink:  #e9edf8;
  --ink-dim: #9aa6c2;
  --ink-faint: #6b7591;

  /* brand flow palette */
  --iris:   #7c5cff;
  --cyan:   #22d3ee;
  --mint:   #34e0b0;
  --magenta:#ff5ca8;
  --amber:  #ffb26b;

  /* glass */
  --glass-bg: rgba(255, 255, 255, 0.055);
  --glass-bg-strong: rgba(255, 255, 255, 0.09);
  --glass-brd: rgba(255, 255, 255, 0.14);
  --glass-hi: rgba(255, 255, 255, 0.55);
  --glass-shadow: 0 20px 60px -20px rgba(2, 6, 23, 0.85);

  --radius: 22px;
  --radius-sm: 14px;
  --maxw: 1180px;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --font: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-display: "Space Grotesk", var(--font);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font);
  color: var(--ink);
  background: var(--bg-0);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

/* ---------- Flowing liquid background ---------- */
.flow-field {
  position: fixed;
  inset: 0;
  z-index: -2;
  overflow: hidden;
  background:
    radial-gradient(1200px 800px at 15% -10%, rgba(124, 92, 255, 0.20), transparent 60%),
    radial-gradient(1000px 700px at 100% 10%, rgba(34, 211, 238, 0.16), transparent 55%),
    radial-gradient(900px 900px at 50% 120%, rgba(255, 92, 168, 0.14), transparent 60%),
    var(--bg-0);
}
.flow-field .blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(60px);
  opacity: 0.55;
  mix-blend-mode: screen;
  animation: drift 24s var(--ease) infinite alternate;
  will-change: transform;
}
.blob.b1 { width: 46vw; height: 46vw; left: -8vw; top: -10vw;
  background: radial-gradient(circle at 30% 30%, var(--iris), transparent 70%); }
.blob.b2 { width: 40vw; height: 40vw; right: -6vw; top: 4vw;
  background: radial-gradient(circle at 60% 40%, var(--cyan), transparent 70%); animation-duration: 30s; }
.blob.b3 { width: 44vw; height: 44vw; left: 20vw; bottom: -18vw;
  background: radial-gradient(circle at 50% 50%, var(--magenta), transparent 70%); animation-duration: 27s; }
.blob.b4 { width: 30vw; height: 30vw; right: 12vw; bottom: -10vw;
  background: radial-gradient(circle at 50% 50%, var(--mint), transparent 70%); animation-duration: 33s; }

@keyframes drift {
  0%   { transform: translate3d(0,0,0) scale(1); }
  50%  { transform: translate3d(4vw, 3vw, 0) scale(1.12); }
  100% { transform: translate3d(-3vw, -2vw, 0) scale(0.96); }
}

/* subtle grain to make the glass feel physical */
.flow-field::after {
  content: "";
  position: absolute; inset: 0;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='140' height='140'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.035'/%3E%3C/svg%3E");
  z-index: -1;
}

/* ---------- Layout ---------- */
.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 clamp(1.1rem, 4vw, 2.4rem); }
section { position: relative; }
.eyebrow {
  display: inline-flex; align-items: center; gap: 0.5rem;
  font-family: var(--font-display);
  font-size: 0.78rem; letter-spacing: 0.22em; text-transform: uppercase;
  color: var(--ink-dim);
}
.eyebrow::before { content: ""; width: 26px; height: 1px; background: linear-gradient(90deg, var(--iris), var(--cyan)); }

h1, h2, h3 { font-family: var(--font-display); line-height: 1.12; margin: 0; font-weight: 600; letter-spacing: -0.01em; }

.gradient-text {
  background: linear-gradient(100deg, var(--iris), var(--cyan) 40%, var(--mint) 70%, var(--magenta));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}

/* ---------- Glass primitives ---------- */
.glass {
  position: relative;
  background: var(--glass-bg);
  border: 1px solid var(--glass-brd);
  border-radius: var(--radius);
  backdrop-filter: blur(18px) saturate(150%);
  -webkit-backdrop-filter: blur(18px) saturate(150%);
  box-shadow: var(--glass-shadow), inset 0 1px 0 0 var(--glass-hi);
  overflow: hidden;
}
/* specular sheen sweeping the top edge */
.glass::before {
  content: ""; position: absolute; inset: 0; border-radius: inherit; pointer-events: none;
  background: linear-gradient(180deg, rgba(255,255,255,0.16), transparent 30%);
  opacity: 0.7;
}

/* ---------- Nav ---------- */
.nav {
  position: sticky; top: 0; z-index: 50;
  padding: 0.7rem 0;
  backdrop-filter: blur(14px) saturate(160%);
  -webkit-backdrop-filter: blur(14px) saturate(160%);
  background: rgba(5, 7, 15, 0.45);
  border-bottom: 1px solid rgba(255,255,255,0.06);
}
.nav .wrap { display: flex; align-items: center; justify-content: space-between; gap: 1rem; }
.brand { display: flex; align-items: center; gap: 0.6rem; font-family: var(--font-display); font-weight: 600; letter-spacing: 0.02em; text-decoration: none; color: var(--ink); }
.brand .mark {
  width: 30px; height: 30px; border-radius: 9px; flex: none;
  background: conic-gradient(from 140deg, var(--iris), var(--cyan), var(--mint), var(--magenta), var(--iris));
  box-shadow: 0 0 0 1px rgba(255,255,255,0.18) inset, 0 6px 18px -6px var(--iris);
}
.nav-links { display: flex; align-items: center; gap: 1.4rem; }
.nav-links a { color: var(--ink-dim); text-decoration: none; font-size: 0.92rem; transition: color 0.2s; }
.nav-links a:hover { color: var(--ink); }
@media (max-width: 640px) { .nav-links a.hide-sm { display: none; } }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 0.55rem;
  padding: 0.72rem 1.25rem; border-radius: 999px;
  font-weight: 600; font-size: 0.95rem; text-decoration: none;
  border: 1px solid transparent; cursor: pointer;
  transition: transform 0.2s var(--ease), box-shadow 0.2s, background 0.2s;
}
.btn-primary {
  color: #0a0a12;
  background: linear-gradient(100deg, var(--cyan), var(--mint));
  box-shadow: 0 10px 30px -10px var(--cyan);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 16px 40px -12px var(--cyan); }
.btn-ghost { color: var(--ink); background: var(--glass-bg-strong); border-color: var(--glass-brd); backdrop-filter: blur(8px); }
.btn-ghost:hover { transform: translateY(-2px); border-color: rgba(255,255,255,0.28); }

/* ---------- Hero ---------- */
.hero { padding: clamp(3.5rem, 9vw, 7rem) 0 clamp(2.5rem, 6vw, 4rem); text-align: center; }
.hero h1 { font-size: clamp(2.5rem, 7vw, 4.8rem); margin: 1.1rem auto 0; max-width: 15ch; }
.hero .lede { max-width: 46ch; margin: 1.3rem auto 0; color: var(--ink-dim); font-size: clamp(1.02rem, 2.4vw, 1.2rem); }
.hero-cta { display: flex; gap: 0.8rem; justify-content: center; flex-wrap: wrap; margin-top: 2rem; }
.chips { display: flex; gap: 0.5rem; justify-content: center; flex-wrap: wrap; margin-top: 2.4rem; }
.chip {
  font-size: 0.8rem; padding: 0.4rem 0.85rem; border-radius: 999px;
  border: 1px solid var(--glass-brd); background: var(--glass-bg); color: var(--ink-dim);
  backdrop-filter: blur(8px);
}
.chip strong { color: var(--ink); font-weight: 600; }

/* ---------- Split zones ---------- */
.zones { display: grid; grid-template-columns: 1fr 1fr; gap: 1.4rem; margin-top: 1rem; }
@media (max-width: 860px) { .zones { grid-template-columns: 1fr; } }
.zone { padding: clamp(1.5rem, 3vw, 2.2rem); min-height: 260px; display: flex; flex-direction: column; }
.zone h2 { font-size: clamp(1.5rem, 3.2vw, 2.1rem); margin-top: 0.7rem; }
.zone p { color: var(--ink-dim); margin: 0.7rem 0 0; }
.zone .btn { margin-top: auto; align-self: flex-start; }
.zone-icon { width: 52px; height: 52px; border-radius: 15px; display: grid; place-items: center; font-size: 1.5rem;
  border: 1px solid var(--glass-brd); background: var(--glass-bg-strong); }
.zone.science { background:
  linear-gradient(160deg, rgba(34,211,238,0.10), transparent 55%), var(--glass-bg); }
.zone.creative { background:
  linear-gradient(160deg, rgba(255,92,168,0.12), transparent 55%), var(--glass-bg); }

/* ---------- Section headers ---------- */
.sec-head { display: flex; align-items: flex-end; justify-content: space-between; gap: 1rem; margin: clamp(3.5rem,7vw,5.5rem) 0 1.6rem; flex-wrap: wrap; }
.sec-head h2 { font-size: clamp(1.7rem, 4vw, 2.6rem); margin-top: 0.6rem; }
.sec-head .link { color: var(--cyan); text-decoration: none; font-weight: 600; font-size: 0.95rem; white-space: nowrap; }
.sec-head .link:hover { text-decoration: underline; }

/* ---------- Writing cards ---------- */
.posts { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 1.2rem; }
.post {
  display: flex; flex-direction: column; padding: 1.4rem;
  text-decoration: none; color: inherit;
  transition: transform 0.25s var(--ease), border-color 0.25s;
}
.post:hover { transform: translateY(-4px); border-color: rgba(255,255,255,0.3); }
.post .kicker { font-size: 0.74rem; letter-spacing: 0.14em; text-transform: uppercase; color: var(--ink-faint); }
.post h3 { font-size: 1.18rem; margin: 0.6rem 0 0.7rem; }
.post p { color: var(--ink-dim); font-size: 0.94rem; margin: 0 0 1.1rem; flex: 1; }
.post .tags { display: flex; flex-wrap: wrap; gap: 0.4rem; }
.tag { font-size: 0.72rem; padding: 0.25rem 0.6rem; border-radius: 999px; background: rgba(124,92,255,0.14); color: #c9bcff; border: 1px solid rgba(124,92,255,0.25); }
.post .more { margin-top: 1rem; color: var(--cyan); font-weight: 600; font-size: 0.9rem; }

/* ---------- Art gallery ---------- */
.gallery { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 1.2rem; }
.art-tile {
  position: relative; aspect-ratio: 4 / 3; border-radius: var(--radius);
  overflow: hidden; text-decoration: none; color: var(--ink);
  border: 1px solid var(--glass-brd);
  transition: transform 0.3s var(--ease);
}
.art-tile:hover { transform: translateY(-5px) scale(1.01); }
.art-tile .canvas { position: absolute; inset: 0; }
.art-tile .meta {
  position: absolute; inset: auto 0 0 0; padding: 1.1rem;
  background: linear-gradient(0deg, rgba(4,6,14,0.85), transparent);
  backdrop-filter: blur(2px);
}
.art-tile .meta h3 { font-size: 1.05rem; }
.art-tile .meta span { font-size: 0.8rem; color: var(--ink-dim); }
.art-tile.placeholder { display: grid; place-items: center; text-align: center; background: var(--glass-bg); }
.art-tile.placeholder .plus { font-size: 2rem; color: var(--ink-faint); }
.art-tile.placeholder p { color: var(--ink-faint); font-size: 0.85rem; margin: 0.4rem 1.5rem 0; }

/* liquid-glass demo canvases (pure CSS) */
.lg { position: absolute; inset: 0; background:
  radial-gradient(120% 120% at 20% 15%, rgba(255,255,255,0.35), transparent 40%),
  linear-gradient(135deg, var(--iris), var(--cyan)); }
.lg::after { content:""; position:absolute; inset:0; backdrop-filter: blur(0);
  background:
    radial-gradient(60% 50% at 70% 80%, rgba(255,92,168,0.6), transparent 60%),
    radial-gradient(50% 40% at 30% 70%, rgba(52,224,176,0.55), transparent 60%); mix-blend-mode: screen; }
.lg.alt { background: linear-gradient(135deg, var(--magenta), var(--amber)); }
.lg.alt::after { background: radial-gradient(60% 50% at 30% 20%, rgba(34,211,238,0.6), transparent 60%); }

/* ---------- About strip ---------- */
.about { padding: clamp(1.8rem, 4vw, 3rem); text-align: center; margin-top: 1rem; }
.about h2 { font-size: clamp(1.6rem, 3.6vw, 2.3rem); max-width: 22ch; margin: 0.6rem auto 0; }
.about p { color: var(--ink-dim); max-width: 58ch; margin: 1.1rem auto 0; }
.formula { display: flex; gap: 0.6rem; justify-content: center; flex-wrap: wrap; margin-top: 1.8rem; font-family: var(--font-display); }
.formula span { padding: 0.5rem 1rem; border-radius: 12px; border: 1px solid var(--glass-brd); background: var(--glass-bg); }
.formula .op { border: none; background: none; color: var(--ink-faint); align-self: center; }

/* ---------- Footer ---------- */
footer.site { margin-top: clamp(4rem, 8vw, 6rem); padding: 2.5rem 0; border-top: 1px solid rgba(255,255,255,0.07); }
footer.site .wrap { display: flex; justify-content: space-between; align-items: center; gap: 1rem; flex-wrap: wrap; }
footer.site a { color: var(--ink-dim); text-decoration: none; }
footer.site a:hover { color: var(--ink); }
.socials { display: flex; gap: 1.2rem; }

/* pointer-reactive specular highlight (JS sets --mx/--my) */
[data-tilt] { position: relative; }
[data-tilt]::after {
  content: ""; position: absolute; inset: 0; border-radius: inherit; pointer-events: none;
  background: radial-gradient(180px 180px at var(--mx, 50%) var(--my, 0%), rgba(255,255,255,0.16), transparent 60%);
  opacity: 0; transition: opacity 0.3s var(--ease);
}
[data-tilt]:hover::after { opacity: 1; }

/* ---------- Article (Medium-portable posts) ---------- */
.article { max-width: 720px; margin: 0 auto; padding: clamp(2rem,5vw,3.5rem) 0 4rem; }
.article header { margin-bottom: 2rem; }
.article h1 { font-size: clamp(2rem, 5vw, 3rem); line-height: 1.15; }
.article .dek { color: var(--ink-dim); font-size: 1.2rem; margin-top: 1rem; }
.article .byline { color: var(--ink-faint); font-size: 0.9rem; margin-top: 1.2rem; display: flex; gap: 0.6rem; flex-wrap: wrap; }
.article-body { font-size: 1.12rem; line-height: 1.8; }
.article-body > * { margin: 0 0 1.35rem; }
.article-body h2 { font-size: 1.6rem; margin-top: 2.6rem; }
.article-body h3 { font-size: 1.28rem; margin-top: 2rem; }
.article-body a { color: var(--cyan); }
.article-body blockquote {
  margin: 1.8rem 0; padding: 0.4rem 0 0.4rem 1.4rem;
  border-left: 3px solid var(--iris); color: var(--ink); font-style: italic;
}
.article-body figure { margin: 2rem 0; }
.article-body figure img { width: 100%; border-radius: var(--radius-sm); border: 1px solid var(--glass-brd); display: block; }
.article-body figcaption { text-align: center; color: var(--ink-faint); font-size: 0.88rem; margin-top: 0.6rem; }
.article-body pre {
  background: rgba(0,0,0,0.45); border: 1px solid var(--glass-brd); border-radius: var(--radius-sm);
  padding: 1.1rem 1.2rem; overflow-x: auto; font-size: 0.92rem;
}
.article-body code { font-family: "SF Mono", ui-monospace, Menlo, monospace; font-size: 0.92em; }
.article-body p > code { background: rgba(124,92,255,0.16); padding: 0.1em 0.4em; border-radius: 6px; }
.article-body ul, .article-body ol { padding-left: 1.4rem; }
.article-body li { margin: 0.5rem 0; }
.article-body hr { border: none; border-top: 1px solid rgba(255,255,255,0.12); margin: 2.5rem 0; }
.note-box {
  margin: 2.5rem auto; max-width: 720px; padding: 1.2rem 1.4rem;
  font-size: 0.92rem; color: var(--ink-dim);
}
.note-box strong { color: var(--ink); }

/* ---------- Reveal on scroll ---------- */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity 0.7s var(--ease), transform 0.7s var(--ease); }
.reveal.in { opacity: 1; transform: none; }

/* ---------- Accessibility ---------- */
:focus-visible { outline: 2px solid var(--cyan); outline-offset: 3px; border-radius: 6px; }
.skip { position: absolute; left: -9999px; top: 0; background: var(--cyan); color: #04121a; padding: 0.7rem 1rem; border-radius: 0 0 10px 0; z-index: 100; }
.skip:focus { left: 0; }

@media (prefers-reduced-motion: reduce) {
  .flow-field .blob { animation: none; }
  .reveal { transition: none; opacity: 1; transform: none; }
  html { scroll-behavior: auto; }
  .btn, .post, .art-tile { transition: none; }
}