/* ============================================================
   Jennifer Fung — shared styles
   Light editorial system. Warm paper, ink, a single cobalt accent.
   Accessibility-first: AA+ contrast, focus-visible, reduced-motion.
   ============================================================ */

:root {
  /* surface — luminous misty base, not white */
  --paper:      #E7EBE4;            /* soft sage mist */
  --paper-2:    #DBE1D9;           /* recessed panel */
  --card:       rgba(250, 249, 243, 0.74); /* frosted raised card */
  --card-solid: #F8F7F0;
  /* ink */
  --ink:      #14130F;   /* primary text — ~13:1 on base */
  --ink-2:    #3A3933;   /* secondary */
  --muted:    #4F4B41;   /* labels — ~6:1 on base (AA) */
  /* lines */
  --line:        rgba(20, 19, 15, 0.13);
  --line-strong: rgba(20, 19, 15, 0.24);
  /* accent — deep teal-jade (water) */
  --accent:     #145863;   /* links / interaction — AA */
  --accent-ink: #0e424b;   /* hover */
  --spark:      #2E8A99;   /* bright teal — decorative strokes */
  --clay:       #BC5A22;   /* ember warmth — awards / rare highlight */
  /* elemental washes (Avatar-inspired) */
  --water: 46, 138, 153;
  --earth: 79, 126, 94;
  --fire:  200, 112, 47;
  --air:   127, 167, 166;
  --sun:   216, 162, 58;
  /* type */
  --display: "Fraunces", "Times New Roman", serif;
  --sans:    "Hanken Grotesk", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --mono:    "IBM Plex Mono", ui-monospace, "SFMono-Regular", monospace;
  /* system */
  --maxw:   1140px;
  --gutter: clamp(20px, 5vw, 72px);
  --ease:   cubic-bezier(0.22, 1, 0.36, 1);
}

/* animatable wash colors — let the elemental atmosphere morph per section */
@property --c-a { syntax: "<color>"; inherits: true; initial-value: rgba(46,138,153,0.42); }
@property --c-b { syntax: "<color>"; inherits: true; initial-value: rgba(127,167,166,0.30); }
@property --c-c { syntax: "<color>"; inherits: true; initial-value: rgba(79,126,94,0.40); }
@property --c-d { syntax: "<color>"; inherits: true; initial-value: rgba(216,162,58,0.22); }
@property --spark2 { syntax: "<color>"; inherits: true; initial-value: #2E8A99; }
html {
  transition: --c-a 1.6s var(--ease), --c-b 1.6s var(--ease),
              --c-c 1.6s var(--ease), --c-d 1.6s var(--ease),
              --spark2 1.2s var(--ease);
}

*, *::before, *::after { box-sizing: border-box; }
* { margin: 0; padding: 0; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  font-family: var(--sans);
  font-weight: 400;
  font-size: clamp(1rem, 0.96rem + 0.2vw, 1.075rem);
  line-height: 1.65;
  color: var(--ink);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

/* painterly atmosphere: drifting elemental washes + watercolor grain */
body::before {
  content: "";
  position: fixed; inset: -16vmax; z-index: -2; pointer-events: none;
  background:
    radial-gradient(54vmax 50vmax at 14% 6%,  var(--c-a), transparent 58%),
    radial-gradient(48vmax 46vmax at 88% 12%, var(--c-d), transparent 60%),
    radial-gradient(56vmax 52vmax at 80% 88%, var(--c-c), transparent 60%),
    radial-gradient(46vmax 44vmax at 6% 92%,  var(--c-b), transparent 62%),
    radial-gradient(40vmax 36vmax at 50% 50%, rgba(var(--fire),  0.09), transparent 60%),
    radial-gradient(72vmax 56vmax at 50% 42%, rgba(231, 235, 228, 0.52), transparent 66%);
  filter: blur(26px) saturate(118%);
  animation: drift 34s ease-in-out infinite alternate;
  will-change: transform;
}
@keyframes drift {
  0%   { transform: translate3d(0, 0, 0) scale(1.04); }
  100% { transform: translate3d(2.5%, -2%, 0) scale(1.12); }
}
body::after {
  content: "";
  position: fixed; inset: 0; z-index: -1; pointer-events: none; opacity: 0.85;
  mix-blend-mode: multiply;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='180' height='180'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.8' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.06'/%3E%3C/svg%3E");
}

/* ---------- typography ---------- */
.display { font-family: var(--display); font-weight: 470; line-height: 1.02; letter-spacing: -0.015em; font-optical-sizing: auto; }
.serif-italic { font-family: var(--display); font-style: italic; font-weight: 430; }
.mono {
  font-family: var(--mono); font-weight: 500; font-size: 0.72rem;
  letter-spacing: 0.16em; text-transform: uppercase; color: var(--muted);
}

::selection { background: var(--accent); color: var(--paper); }

a { color: var(--accent); text-decoration: none; }

/* ---------- skip link / focus ---------- */
.skip {
  position: absolute; left: 16px; top: -64px; z-index: 200;
  background: var(--ink); color: var(--paper); padding: 11px 18px;
  border-radius: 8px; font-family: var(--mono); font-size: 0.72rem;
  letter-spacing: 0.08em; transition: top 0.2s var(--ease);
}
.skip:focus { top: 16px; }
:focus-visible { outline: 2.5px solid var(--accent); outline-offset: 3px; border-radius: 3px; }

/* ---------- layout ---------- */
.wrap { width: 100%; max-width: var(--maxw); margin-inline: auto; padding-inline: var(--gutter); }
section { position: relative; }

/* ---------- nav ---------- */
.nav {
  position: sticky; top: 0; z-index: 100;
  display: flex; align-items: center; justify-content: space-between;
  height: 70px; padding-inline: var(--gutter);
  backdrop-filter: blur(10px) saturate(140%); -webkit-backdrop-filter: blur(10px) saturate(140%);
  background: color-mix(in srgb, var(--paper) 78%, transparent);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s var(--ease), background 0.3s var(--ease);
}
.nav.scrolled { border-bottom-color: var(--line); }
.nav .brand {
  font-family: var(--display); font-weight: 500; font-size: 1.28rem;
  color: var(--ink); letter-spacing: -0.01em; display: inline-flex; align-items: center; gap: 11px;
}
.nav .brand .mark {
  width: 13px; height: 13px; border-radius: 50%;
  border: 1.5px solid var(--accent); position: relative;
}
.nav .brand .mark::after {
  content: ""; position: absolute; inset: 3px; border-radius: 50%; background: var(--accent);
  transform: scale(0.6); transition: transform 0.4s var(--ease);
}
.nav .brand:hover .mark::after { transform: scale(1); }
.nav .links { display: flex; gap: clamp(16px, 2.4vw, 38px); }
.nav .links a {
  font-family: var(--mono); font-size: 0.7rem; letter-spacing: 0.12em; text-transform: uppercase;
  color: var(--ink-2); position: relative; padding: 4px 0;
}
.nav .links a::after {
  content: ""; position: absolute; left: 0; bottom: 0; width: 100%; height: 1.5px;
  background: var(--accent); transform: scaleX(0); transform-origin: left; transition: transform 0.32s var(--ease);
}
.nav .links a:hover { color: var(--ink); }
.nav .links a:hover::after { transform: scaleX(1); }
.nav .back { font-family: var(--mono); font-size: 0.7rem; letter-spacing: 0.1em; text-transform: uppercase; color: var(--ink-2); display: inline-flex; gap: 8px; align-items: center; }
.nav .back:hover { color: var(--ink); }
.nav .back .ar { transition: transform 0.3s var(--ease); }
.nav .back:hover .ar { transform: translateX(-3px); }
@media (max-width: 680px) { .nav .links { display: none; } }

/* ---------- eyebrow ---------- */
.eyebrow { display: inline-flex; align-items: center; gap: 12px; margin-bottom: 22px; }
.eyebrow::before { content: ""; width: 28px; height: 1.5px; background: var(--spark2); transition: background 1.2s var(--ease); }

/* ---------- section heading ---------- */
.sec-head { font-family: var(--display); font-weight: 470; font-size: clamp(2rem, 1.1rem + 3.4vw, 3.5rem); line-height: 1.05; letter-spacing: -0.02em; max-width: 20ch; }
.sec-lede { margin-top: 22px; max-width: 56ch; color: var(--ink-2); font-size: clamp(1.05rem, 1rem + 0.3vw, 1.2rem); }

/* ---------- buttons / links ---------- */
.cta {
  display: inline-flex; align-items: center; gap: 10px;
  font-family: var(--mono); font-size: 0.74rem; letter-spacing: 0.06em; text-transform: uppercase;
  color: var(--ink); padding-bottom: 5px; border-bottom: 1.5px solid var(--accent);
  transition: gap 0.3s var(--ease), color 0.2s var(--ease);
}
.cta .ar { color: var(--accent); transition: transform 0.3s var(--ease); }
.cta:hover { gap: 16px; }
.cta:hover .ar { transform: translateX(4px); }
.cta[aria-disabled="true"] { color: var(--muted); border-bottom-color: var(--line-strong); pointer-events: none; }
.cta[aria-disabled="true"] .ar { color: var(--muted); }

/* ---------- reveal animation ---------- */
.reveal { opacity: 0; transform: translateY(20px); filter: blur(7px); transition: opacity 0.85s var(--ease), transform 0.85s var(--ease), filter 0.85s var(--ease); }
.reveal.in { opacity: 1; transform: none; filter: none; }

/* ---------- footer ---------- */
.foot { border-top: 1px solid var(--line); margin-top: clamp(60px, 10vh, 130px); padding-block: clamp(64px, 9vh, 110px); }
.foot .grid { display: grid; grid-template-columns: 1.4fr 1fr; gap: clamp(36px, 6vw, 80px); align-items: end; }
@media (max-width: 720px) { .foot .grid { grid-template-columns: 1fr; gap: 40px; align-items: start; } }
.foot .big { font-family: var(--display); font-weight: 470; font-size: clamp(1.9rem, 1rem + 3vw, 3.2rem); line-height: 1.08; letter-spacing: -0.02em; max-width: 16ch; }
.foot .big em { font-style: italic; color: var(--accent); }
.foot .contact { display: grid; gap: 14px; }
.foot .contact a { display: inline-flex; align-items: center; gap: 9px; font-family: var(--mono); font-size: 0.82rem; letter-spacing: 0.02em; color: var(--ink-2); width: max-content; border-bottom: 1px solid transparent; padding-bottom: 2px; transition: color 0.25s var(--ease), border-color 0.25s var(--ease); }
.foot .contact a:hover { color: var(--ink); border-bottom-color: var(--accent); }
.foot .colophon { margin-top: clamp(40px, 7vh, 72px); display: flex; justify-content: space-between; flex-wrap: wrap; gap: 16px; font-family: var(--mono); font-size: 0.68rem; letter-spacing: 0.05em; color: var(--muted); }

/* ============================================================
   Case-study pages
   ============================================================ */
.cs-wrap { max-width: 820px; margin-inline: auto; padding-inline: var(--gutter); }

.cs-hero { padding-block: clamp(60px, 11vh, 130px) clamp(30px, 5vh, 56px); }
.cs-title { font-family: var(--display); font-weight: 470; font-size: clamp(2.4rem, 1.2rem + 4.6vw, 4.4rem); line-height: 1.02; letter-spacing: -0.025em; margin: 18px 0 24px; }
.cs-title em { font-style: italic; color: var(--accent); }
.cs-summary { font-size: clamp(1.15rem, 1rem + 0.7vw, 1.5rem); line-height: 1.45; color: var(--ink-2); max-width: 40ch; }

.cs-banner { aspect-ratio: 16 / 7; border-radius: 16px; overflow: hidden; border: 1px solid var(--line); margin-block: clamp(28px, 5vh, 56px); position: relative; background: var(--card); box-shadow: 0 30px 70px -50px rgba(23,20,15,0.5); }
.cs-banner svg { position: absolute; inset: 0; width: 100%; height: 100%; }

.cs-facts { display: grid; grid-template-columns: repeat(4, 1fr); gap: 22px; padding: 26px 0; border-block: 1px solid var(--line); margin-bottom: clamp(34px, 6vh, 64px); }
@media (max-width: 620px) { .cs-facts { grid-template-columns: repeat(2, 1fr); gap: 24px 18px; } }
.cs-facts dt { font-family: var(--mono); font-size: 0.62rem; letter-spacing: 0.16em; text-transform: uppercase; color: var(--muted); margin-bottom: 7px; }
.cs-facts dd { font-size: 0.96rem; color: var(--ink); font-weight: 500; line-height: 1.35; }

/* prose */
.prose { max-width: 68ch; }
.prose h2 { font-family: var(--display); font-weight: 480; font-size: clamp(1.6rem, 1.1rem + 1.8vw, 2.3rem); line-height: 1.1; letter-spacing: -0.018em; margin: clamp(46px, 7vh, 78px) 0 18px; }
.prose h2 .idx { font-family: var(--mono); font-size: 0.7rem; letter-spacing: 0.14em; color: var(--accent); vertical-align: middle; margin-right: 14px; }
.prose h3 { font-family: var(--display); font-weight: 500; font-size: 1.25rem; margin: 32px 0 10px; }
.prose p { color: var(--ink-2); margin-bottom: 20px; }
.prose p strong { color: var(--ink); font-weight: 600; }
.prose a { border-bottom: 1px solid color-mix(in srgb, var(--accent) 50%, transparent); transition: border-color 0.2s var(--ease); }
.prose a:hover { border-bottom-color: var(--accent); }
.prose ul { list-style: none; margin: 22px 0; display: grid; gap: 14px; }
.prose ul li { position: relative; padding-left: 26px; color: var(--ink-2); }
.prose ul li::before { content: ""; position: absolute; left: 0; top: 0.62em; width: 9px; height: 9px; border: 1.5px solid var(--accent); border-radius: 50%; }
.prose ul li strong { color: var(--ink); }

.callout { background: var(--card); border: 1px solid var(--line); border-left: 3px solid var(--accent); border-radius: 12px; padding: 22px 24px; margin: 28px 0; }
.callout p:last-child { margin-bottom: 0; }
.pullquote { font-family: var(--display); font-style: italic; font-weight: 430; font-size: clamp(1.4rem, 1.1rem + 1.5vw, 2.1rem); line-height: 1.28; color: var(--ink); margin: clamp(40px, 6vh, 68px) 0; padding-left: 26px; border-left: 2px solid var(--accent); max-width: 24ch; }

.results { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; margin: 30px 0; }
@media (max-width: 600px) { .results { grid-template-columns: 1fr; } }
.result { background: var(--card); border: 1px solid var(--line); border-radius: 13px; padding: 24px 22px; }
.result .num { font-family: var(--display); font-weight: 480; font-size: 2.1rem; line-height: 1; color: var(--accent); margin-bottom: 8px; }
.result .cap { font-size: 0.92rem; color: var(--ink-2); }

.note { font-family: var(--mono); font-size: 0.7rem; letter-spacing: 0.04em; color: var(--muted); margin-top: 6px; }

/* painterly "aurora" blob mesh + flowing river-dragon of light (shared: hero cards + case-study banners) */
.pv .blob { transform-box: fill-box; transform-origin: center; }
@media (prefers-reduced-motion: no-preference) {
  .pv .d1 { animation: pv-drift-1 23s ease-in-out infinite alternate; }
  .pv .d2 { animation: pv-drift-2 29s ease-in-out infinite alternate; }
  .pv .d3 { animation: pv-drift-3 33s ease-in-out infinite alternate; }
  .pv .d4 { animation: pv-drift-4 26s ease-in-out infinite alternate; }
  .pv .flow { animation: pv-flow 8.5s linear infinite; }
}
@keyframes pv-drift-1 { to { transform: translate(15px, -11px) scale(1.08); } }
@keyframes pv-drift-2 { to { transform: translate(-13px, 12px) scale(1.06); } }
@keyframes pv-drift-3 { to { transform: translate(10px, 14px) scale(1.05); } }
@keyframes pv-drift-4 { to { transform: translate(-9px, -13px) scale(1.07); } }
@keyframes pv-flow { to { stroke-dashoffset: -360; } }

/* case-study UX phone showcase + demo video + resource links */
.ux-showcase { margin: clamp(40px, 7vh, 72px) 0; display: grid; gap: clamp(26px, 4vh, 44px); }
.phone { background: #14130f; padding: 7px; border-radius: 34px; border: 1px solid rgba(20,19,15,0.18); box-shadow: 0 46px 100px -52px rgba(23,20,15,0.6), inset 0 0 0 1.5px rgba(255,255,255,0.06); }
.phone > .screen { position: relative; border-radius: 27px; overflow: hidden; background: #e7ebe4; }
.phone img, .phone video { display: block; width: 100%; height: auto; }
.phone .notch { position: absolute; top: 8px; left: 50%; transform: translateX(-50%); width: 36%; height: 16px; background: #14130f; border-radius: 0 0 12px 12px; z-index: 2; }
.ux-feature { display: flex; flex-wrap: wrap; align-items: center; justify-content: center; gap: clamp(24px, 4vw, 52px); }
.ux-feature .phone { width: 248px; max-width: 70vw; flex: none; }
.ux-feature figcaption { max-width: 30ch; }
.ux-feature figcaption .k { font-family: var(--mono); font-size: 0.66rem; letter-spacing: 0.16em; text-transform: uppercase; color: var(--muted); display: block; margin-bottom: 10px; }
.ux-feature figcaption p { color: var(--ink-2); margin: 0; font-size: 1.02rem; line-height: 1.55; }
.ux-phones { display: flex; gap: clamp(14px, 2.2vw, 26px); justify-content: center; align-items: flex-start; flex-wrap: wrap; }
.ux-phones figure { width: 196px; max-width: 42vw; margin: 0; }
.ux-phones .phone { width: 100%; }
.ux-phones figcaption { margin-top: 13px; text-align: center; font-family: var(--mono); font-size: 0.64rem; letter-spacing: 0.06em; color: var(--muted); line-height: 1.4; }
.ux-phones figcaption b { display: block; color: var(--ink); font-weight: 600; letter-spacing: 0.02em; margin-bottom: 3px; }
.cs-links { display: flex; flex-wrap: wrap; gap: 14px; margin: 26px 0 6px; }
.cs-links a { display: inline-flex; align-items: center; gap: 9px; font-family: var(--mono); font-size: 0.76rem; letter-spacing: 0.04em; padding: 11px 18px; border: 1px solid var(--line); border-radius: 999px; color: var(--ink); text-decoration: none; transition: border-color 0.3s var(--ease), color 0.3s var(--ease), transform 0.3s var(--ease); }
.cs-links a:hover { border-color: var(--accent); color: var(--accent); transform: translateY(-2px); }

/* next / prev */
.cs-next { border-top: 1px solid var(--line); margin-top: clamp(56px, 9vh, 100px); padding-block: clamp(48px, 8vh, 90px); }
.cs-next a { display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.cs-next .nx { font-family: var(--display); font-weight: 470; font-size: clamp(1.5rem, 1rem + 2.4vw, 2.6rem); line-height: 1.08; letter-spacing: -0.02em; color: var(--ink); transition: color 0.3s var(--ease); }
.cs-next a:hover .nx { color: var(--accent); }
.cs-next .ar { font-size: 2rem; color: var(--accent); transition: transform 0.3s var(--ease); }
.cs-next a:hover .ar { transform: translateX(6px); }

/* ---------- scroll progress line ---------- */
.progress { position: fixed; top: 0; left: 0; height: 2px; width: 0; z-index: 300; pointer-events: none; background: linear-gradient(90deg, var(--accent), var(--spark2)); box-shadow: 0 0 10px rgba(var(--water), 0.5); transition: width 0.12s linear; }

/* ---------- cursor-follow ambient light ---------- */
.glow { position: fixed; top: 0; left: 0; width: 40vmax; height: 40vmax; z-index: -1; pointer-events: none; transform: translate3d(-50%, -50%, 0); opacity: 0; transition: opacity 0.8s var(--ease); mix-blend-mode: soft-light; background: radial-gradient(circle, rgba(255,255,255,0.7), rgba(var(--air), 0.12) 38%, transparent 68%); }
.glow.on { opacity: 1; }
@media (pointer: coarse) { .glow { display: none; } }

/* ---------- active nav link (scroll-spy) ---------- */
.nav .links a.active { color: var(--ink); }
.nav .links a.active::after { transform: scaleX(1); }

/* ---------- magnetic tilt ---------- */
.tilt { transform-style: preserve-3d; will-change: transform; }

/* ---------- frosted glass over the washes ---------- */
.spec, .result, .callout {
  backdrop-filter: blur(9px) saturate(130%);
  -webkit-backdrop-filter: blur(9px) saturate(130%);
}

/* ---------- reduced motion ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: 0.001ms !important; animation-iteration-count: 1 !important; transition-duration: 0.001ms !important; }
  .reveal { opacity: 1 !important; transform: none !important; filter: none !important; }
  .glow { display: none !important; }
  .tilt { transform: none !important; }
}