/* ============================================================
   ReWorld — project page styles
   Dark cinematic theme · purple family #3B2FB8 → #534AD1 → #8F7FF0
   ============================================================ */

@font-face {
  font-family: 'Optimistic';
  src: url('Optimistic.ttf') format('truetype');
  font-weight: 100 900; /* single Bold face; avoid synthetic bolding */
  font-display: swap;
}

:root {
  --ground: #0D0F1E;
  --ground-2: #10132a;
  --card: #141834;
  --card-2: #191d3d;
  --ink: #F2F3FB;
  --ink-dim: #ABAECB;
  --ink-faint: #767a9e;
  --p-deep: #3B2FB8;
  --p-mid: #534AD1;
  --p-lav: #8F7FF0;
  --p-pale: #BDB2FA;
  --line: rgba(143, 127, 240, 0.16);
  --line-strong: rgba(143, 127, 240, 0.34);
  --radius: 14px;
  --font-display: 'Optimistic', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --font-body: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --wall-max: 1560px;
  --text-max: 1160px;
}

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

html { scroll-behavior: smooth; }

body {
  background: var(--ground);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

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

a { color: var(--p-pale); text-decoration: none; }
a:hover { color: var(--ink); }

::selection { background: rgba(83, 74, 209, 0.55); color: #fff; }

/* ---------------- Nav ---------------- */

.nav {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 100;
  display: flex;
  align-items: center;
  gap: 28px;
  padding: 14px 28px;
  transition: background .35s ease, border-color .35s ease, backdrop-filter .35s ease;
  border-bottom: 1px solid transparent;
}
.nav.scrolled {
  background: rgba(13, 15, 30, 0.72);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom-color: var(--line);
}
.nav-logo { display: flex; align-items: center; }
.nav-logo img { height: 30px; width: auto; }
.nav-spacer { flex: 1; }
.nav-links { display: flex; gap: 26px; align-items: center; }
.nav-links a {
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.02em;
  color: var(--ink-dim);
}
.nav-links a:hover { color: var(--ink); }
.btn-paper {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 18px;
  border-radius: 999px;
  background: linear-gradient(135deg, var(--p-deep), var(--p-mid) 55%, var(--p-lav));
  color: #fff !important;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.02em;
  border: none;
  box-shadow: 0 2px 18px rgba(83, 74, 209, 0.35);
  transition: box-shadow .25s ease, transform .25s ease;
}
.btn-paper:hover { box-shadow: 0 4px 26px rgba(143, 127, 240, 0.5); transform: translateY(-1px); }

@media (max-width: 760px) {
  .nav-links a:not(.btn-paper) { display: none; }
  .nav {
    gap: 16px;
    padding: 10px max(18px, env(safe-area-inset-right, 0px)) 10px max(18px, env(safe-area-inset-left, 0px));
  }
  .nav-logo img { height: 26px; }
  .btn-paper { padding: 7px 16px; }
}

/* ---------------- Hero ---------------- */

.hero {
  position: sticky;
  top: 0;
  height: 100vh;
  height: 100svh;
  overflow: hidden;
  z-index: 0;
  background: var(--ground);
}
.hero-media {
  position: absolute;
  inset: 0;
  will-change: transform;
}
.hero-media video {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.hero-shade {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(57% 42% at 50% 47%, rgba(9, 10, 22, 0.78) 0%, rgba(9, 10, 22, 0.46) 58%, rgba(9, 10, 22, 0) 100%),
    linear-gradient(180deg, rgba(13,15,30,0.62) 0%, rgba(13,15,30,0.20) 30%, rgba(13,15,30,0.14) 55%, rgba(13,15,30,0.88) 100%),
    radial-gradient(120% 90% at 50% 110%, rgba(59,47,184,0.28) 0%, rgba(13,15,30,0) 55%);
}
.hero-dim {
  position: absolute;
  inset: 0;
  background: var(--ground);
  opacity: var(--dim, 0);
  pointer-events: none;
}
.hero-inner {
  position: relative;
  z-index: 2;
  height: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 0 24px;
  will-change: transform, opacity;
}
/* single soft breathing glow behind the title block */
.hero-inner::before {
  content: '';
  position: absolute;
  z-index: -1;
  left: 50%;
  top: 46%;
  width: min(780px, 86vw);
  height: 360px;
  transform: translate(-50%, -55%);
  background: radial-gradient(50% 50% at 50% 50%, rgba(110, 91, 255, 0.30) 0%, rgba(110, 91, 255, 0.10) 55%, rgba(110, 91, 255, 0) 78%);
  animation: hero-glow 7s ease-in-out infinite;
  pointer-events: none;
}
@keyframes hero-glow {
  0%, 100% { opacity: 0.7; transform: translate(-50%, -55%) scale(0.96); }
  50%      { opacity: 1;   transform: translate(-50%, -55%) scale(1.05); }
}
/* staggered load-in: title, then tagline, then sub, then chips */
@keyframes hero-rise {
  from { opacity: 0; transform: translateY(26px); }
  to   { opacity: 1; transform: none; }
}
.hero-title, .hero-tagline, .hero-sub, .hero-chips {
  animation: hero-rise 0.9s cubic-bezier(.2, .6, .2, 1) both;
}
.hero-title   { animation-delay: 0.15s; }
.hero-tagline { animation-delay: 0.42s; }
.hero-sub     { animation-delay: 0.62s; }
.hero-chips   { animation-delay: 0.82s; }
.hero-title {
  font-family: var(--font-display);
  font-size: clamp(66px, 10.2vw, 144px);
  font-weight: 700;
  line-height: 1.0;
  letter-spacing: -0.03em;
  margin-bottom: 24px;
  text-shadow: 0 2px 16px rgba(8, 9, 20, 0.6), 0 0 60px rgba(8, 9, 20, 0.35);
}
.hero-title .re {
  background: linear-gradient(100deg, #8A78FF 0%, #B3A6FA 55%, #E2DCFF 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero-tagline {
  font-family: var(--font-display);
  font-size: clamp(19px, 2.4vw, 29px);
  font-weight: 500;
  color: #fff;
  letter-spacing: 0.005em;
  text-shadow: 0 2px 20px rgba(8, 9, 20, 0.6);
}
/* hairline gradient rule between title and tagline (echoes the section eyebrows) */
.hero-tagline::before {
  content: '';
  display: block;
  width: 64px;
  height: 2px;
  margin: 0 auto 18px;
  border-radius: 2px;
  background: linear-gradient(90deg, rgba(143,127,240,0) 0%, var(--p-lav) 50%, rgba(143,127,240,0) 100%);
}
.hero-sub {
  margin-top: 13px;
  font-size: clamp(14px, 1.5vw, 17px);
  color: rgba(240, 241, 253, 0.92);
  letter-spacing: 0.01em;
  text-shadow: 0 1px 12px rgba(8, 9, 20, 0.65);
}
.hero-chips {
  display: flex;
  gap: 10px;
  margin-top: 30px;
  flex-wrap: wrap;
  justify-content: center;
}
/* glass pills with gradient borders */
.hero-chips span {
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.04em;
  color: #E8E4FF;
  padding: 7px 17px;
  border-radius: 999px;
  border: 1px solid transparent;
  background:
    linear-gradient(rgba(13, 15, 30, 0.60), rgba(13, 15, 30, 0.60)) padding-box,
    linear-gradient(135deg, rgba(124, 107, 255, 0.75) 0%, rgba(189, 178, 250, 0.30) 55%, rgba(124, 107, 255, 0.55) 100%) border-box;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}
.scroll-cue {
  position: absolute;
  bottom: 34px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 2;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  color: rgba(235, 236, 250, 0.7);
  font-size: 12px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
}
.scroll-cue svg { animation: cue-bob 2.2s ease-in-out infinite; }
@keyframes cue-bob {
  0%, 100% { transform: translateY(0); opacity: .65; }
  50% { transform: translateY(7px); opacity: 1; }
}

/* ---------------- Content shell ---------------- */

.content {
  position: relative;
  z-index: 5;
  background: var(--ground);
  border-radius: 26px 26px 0 0;
  box-shadow: 0 -24px 90px rgba(0, 0, 0, 0.65);
}
.content::before {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: min(680px, 80%);
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--p-lav), transparent);
  opacity: 0.55;
}

section { padding: 110px 28px 40px; content-visibility: auto; contain-intrinsic-size: auto 1200px; }
section:first-of-type { padding-top: 84px; }

.section-head {
  max-width: var(--text-max);
  margin: 0 auto 44px;
}
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 12.5px;
  font-weight: 600;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--p-lav);
  margin-bottom: 16px;
}
.eyebrow::before {
  content: '';
  width: 26px;
  height: 2px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--p-deep), var(--p-lav));
}
.section-head h2 {
  font-family: var(--font-display);
  font-size: clamp(34px, 4.6vw, 58px);
  font-weight: 700;
  line-height: 1.06;
  letter-spacing: -0.015em;
  margin-bottom: 16px;
}
.section-head .lede {
  font-size: clamp(15px, 1.6vw, 17.5px);
  color: var(--ink-dim);
  max-width: 760px;
}
.section-head .lede em { color: var(--p-pale); font-style: normal; }

/* ---------------- Video walls ---------------- */

.wall {
  display: grid;
  gap: 30px 26px;
  max-width: var(--wall-max);
  margin: 0 auto;
  grid-template-columns: repeat(3, 1fr);
}
@media (max-width: 1280px) { .wall { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 940px)  { .wall { grid-template-columns: repeat(2, 1fr); gap: 20px 16px; } }
@media (max-width: 560px)  { .wall { grid-template-columns: 1fr; } }

.wall-ctrl { grid-template-columns: repeat(3, 1fr); }

@media (max-width: 1280px) { .wall-ctrl { grid-template-columns: repeat(2, 1fr); } }

@media (max-width: 560px)  { .wall-ctrl { grid-template-columns: 1fr; } }

.vcard {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--card);
  border: 1px solid var(--line);
  transition: transform .3s ease, border-color .3s ease, box-shadow .3s ease;
}
.vcard:focus-within {
  transform: translateY(-4px);
  border-color: var(--line-strong);
  box-shadow: 0 14px 44px rgba(0, 0, 0, 0.5), 0 0 0 1px rgba(143, 127, 240, 0.12), 0 6px 34px rgba(83, 74, 209, 0.22);
}
@media (hover: hover) {
  .vcard:hover {
    transform: translateY(-4px);
    border-color: var(--line-strong);
    box-shadow: 0 14px 44px rgba(0, 0, 0, 0.5), 0 0 0 1px rgba(143, 127, 240, 0.12), 0 6px 34px rgba(83, 74, 209, 0.22);
  }
}
.vcard video {
  width: 100%;
  aspect-ratio: 1280 / 704;
  object-fit: cover;
  background: var(--card-2);
}
.vcard .caption {
  position: absolute;
  inset: auto 0 0 0;
  z-index: 4;
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 10px;
  padding: 34px 14px 11px;
  background: linear-gradient(180deg, rgba(10, 11, 24, 0) 0%, rgba(10, 11, 24, 0.82) 88%);
  pointer-events: none;
}
.vcard .caption .name {
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.01em;
  color: #fff;
  text-shadow: 0 1px 8px rgba(0, 0, 0, 0.6);
}
.vcard .caption .motion {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--p-pale);
  white-space: nowrap;
  padding-bottom: 2px;
}

/* ---------------- Prompt veil + expand button (all card types) ---------------- */

.prompt-veil {
  position: absolute;
  inset: 0;
  z-index: 2;
  background: linear-gradient(180deg, rgba(9, 10, 22, 0.92) 0%, rgba(9, 10, 22, 0.74) 55%, rgba(9, 10, 22, 0.55) 100%);
  padding: 13px 56px 13px 15px;
  opacity: 0;
  transition: opacity .28s ease;
  pointer-events: none;
}
.prompt-veil .p-label {
  display: block;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--p-lav);
  margin-bottom: 7px;
}
.prompt-veil p {
  font-size: 15px;
  line-height: 1.6;
  color: #E3E5F6;
  display: -webkit-box;
  -webkit-line-clamp: 4;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.vcard:focus-within .prompt-veil,
.longrow .frame:focus-within .prompt-veil { opacity: 1; }
@media (hover: hover) {
  .vcard:hover .prompt-veil,
  .longrow .frame:hover .prompt-veil { opacity: 1; }
}

/* decorative chips/badges step aside while the prompt shows */
.traj-chip, .hero-tag, .dur-badge { transition: opacity .25s ease; }
.vcard:focus-within .traj-chip,
.longrow .frame:focus-within .hero-tag,
.longrow .frame:focus-within .dur-badge {
  opacity: 0;
}
@media (hover: hover) {
  .vcard:hover .traj-chip,
  .longrow .frame:hover .hero-tag,
  .longrow .frame:hover .dur-badge {
    opacity: 0;
  }
}

.expand-btn {
  position: absolute;
  top: 10px;
  right: 10px;
  z-index: 6;
  width: 34px;
  height: 34px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  border: 1px solid rgba(143, 127, 240, 0.4);
  background: rgba(13, 15, 30, 0.66);
  color: var(--p-pale);
  cursor: pointer;
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  transition: background .2s ease, border-color .2s ease, color .2s ease, transform .2s ease;
}
.expand-btn svg { width: 15px; height: 15px; }
.expand-btn:hover, .expand-btn:focus-visible {
  background: rgba(83, 74, 209, 0.55);
  border-color: var(--p-lav);
  color: #fff;
  transform: scale(1.06);
}
.expand-btn:focus-visible { outline: 2px solid var(--p-lav); outline-offset: 2px; }

/* memory hover badge (bottom-right, clear of expand button and prompt text) */
.badge-return {
  position: absolute;
  bottom: 44px;
  right: 10px;
  z-index: 3;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: #EAE6FF;
  background: rgba(59, 47, 184, 0.62);
  border: 1px solid rgba(189, 178, 250, 0.45);
  border-radius: 999px;
  padding: 5px 11px;
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  opacity: 0;
  transform: translateY(6px);
  transition: opacity .28s ease, transform .28s ease;
  pointer-events: none;
}
.vcard:focus-within .badge-return {
  opacity: 1;
  transform: translateY(0);
}
@media (hover: hover) {
  .vcard:hover .badge-return {
    opacity: 1;
    transform: translateY(0);
  }
}

/* trajectory chip (control cards) */
.traj-chip {
  position: absolute;
  top: 10px;
  left: 10px;
  z-index: 3;
  display: inline-flex;
  align-items: center;
  gap: 7px;
  font-size: 11.5px;
  font-weight: 600;
  letter-spacing: 0.06em;
  color: var(--p-pale);
  background: rgba(13, 15, 30, 0.66);
  border: 1px solid rgba(143, 127, 240, 0.4);
  border-radius: 999px;
  padding: 5px 12px 5px 8px;
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  pointer-events: none;
}
.traj-chip svg { width: 16px; height: 16px; stroke: var(--p-lav); }

/* ---------------- Metric scale ---------------- */

/* 2-col: each row is a high&slow / near&fast pair (rules placed after the .wall
   media queries so they win the cascade at every breakpoint) */
.wall-scale {
  grid-template-columns: repeat(2, 1fr);
  max-width: 1200px;
  gap: 34px 28px;
}
@media (max-width: 700px) {
  .wall-scale { grid-template-columns: 1fr; gap: 22px; }
}
/* NEAR & FAST chip: filled variant of the same chip language */
.traj-chip.chip-near {
  background: rgba(59, 47, 184, 0.62);
  border-color: rgba(189, 178, 250, 0.45);
  color: #EAE6FF;
}

/* ---------------- Long horizon ---------------- */

.long-list {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 40px 28px;
}
@media (max-width: 940px) { .long-list { grid-template-columns: 1fr; gap: 40px; } }
.longrow { position: relative; }
.longrow .frame {
  position: relative;
  border-radius: 18px;
  overflow: hidden;
  border: 1px solid var(--line);
  background: var(--card);
  transition: border-color .3s ease, box-shadow .3s ease;
}
.longrow .frame:focus-within {
  border-color: var(--line-strong);
  box-shadow: 0 20px 70px rgba(0, 0, 0, 0.55), 0 8px 44px rgba(83, 74, 209, 0.2);
}
@media (hover: hover) {
  .longrow .frame:hover {
    border-color: var(--line-strong);
    box-shadow: 0 20px 70px rgba(0, 0, 0, 0.55), 0 8px 44px rgba(83, 74, 209, 0.2);
  }
}
.longrow .frame .expand-btn { top: 14px; right: 14px; }
.longrow .frame .prompt-veil { padding: 16px 64px 16px 18px; }
.longrow .frame .prompt-veil p { -webkit-line-clamp: 4; font-size: 15.5px; }
.longrow video {
  width: 100%;
  aspect-ratio: 1280 / 704;
  object-fit: cover;
}
.dur-badge {
  position: absolute;
  top: 16px;
  right: 60px;
  z-index: 3;
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: 0.08em;
  font-variant-numeric: tabular-nums;
  color: #fff;
  background: rgba(13, 15, 30, 0.6);
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 999px;
  padding: 6px 13px;
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
}
.hero-tag {
  position: absolute;
  top: 14px;
  left: 14px;
  z-index: 3;
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: #fff;
  background: linear-gradient(135deg, var(--p-deep), var(--p-mid));
  border-radius: 999px;
  padding: 6px 13px;
  box-shadow: 0 2px 14px rgba(59, 47, 184, 0.5);
}
.longrow .meta {
  display: flex;
  align-items: baseline;
  gap: 16px;
  padding: 16px 6px 0;
}
.longrow .idx {
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 700;
  color: var(--p-lav);
  font-variant-numeric: tabular-nums;
}
.longrow .title {
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 600;
  color: var(--ink);
}
.longrow .note {
  font-size: 14.5px;
  color: var(--ink-dim);
}
@media (max-width: 760px) {
  .longrow .meta { flex-direction: column; gap: 4px; }
}

/* ---------------- Method ---------------- */

.method-figure {
  max-width: var(--text-max);
  margin: 0 auto 26px;
  background: var(--ground); /* matches the PNG canvas exactly — no seam */
  border-radius: 20px;
  padding: clamp(18px, 3vw, 40px);
  border: 1px solid var(--line-strong);
  box-shadow: 0 24px 80px rgba(0, 0, 0, 0.45);
}
.method-figure img { width: 100%; height: auto; border-radius: 6px; }
.fig-hint { display: none; } /* mobile-only "scroll →" cue, see mobile layer */
.method-figure figcaption {
  margin-top: 14px;
  font-size: 13.5px;
  color: var(--ink-dim);
  text-align: center;
}
.method-cards {
  max-width: var(--text-max);
  margin: 42px auto 0;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}
@media (max-width: 940px) { .method-cards { grid-template-columns: 1fr; } }
.mcard {
  background: linear-gradient(165deg, var(--card-2) 0%, var(--card) 60%);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 26px 24px 28px;
  transition: border-color .3s ease, transform .3s ease;
}
.mcard:hover { border-color: var(--line-strong); transform: translateY(-3px); }
.mcard .num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  border-radius: 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 15px;
  color: #fff;
  background: linear-gradient(135deg, var(--p-deep), var(--p-lav));
  margin-bottom: 16px;
  box-shadow: 0 4px 18px rgba(83, 74, 209, 0.4);
}
.mcard h3 {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 600;
  margin-bottom: 10px;
  letter-spacing: 0.005em;
}
.mcard p { font-size: 14.5px; color: var(--ink-dim); }
.mcard p strong { color: var(--p-pale); font-weight: 600; }

/* ---------------- Footer ---------------- */

.footer {
  margin-top: 44px;
  border-top: 1px solid var(--line);
  background:
    radial-gradient(90% 120% at 50% 120%, rgba(59, 47, 184, 0.16) 0%, rgba(13, 15, 30, 0) 60%),
    var(--ground);
  padding: 74px 28px 44px;
}
.footer-inner { max-width: var(--text-max); margin: 0 auto; }
.footer-logo img { height: 44px; width: auto; margin-bottom: 26px; }
.authors {
  font-size: 16.5px;
  line-height: 1.85;
  max-width: 860px;
  color: var(--ink);
}
.authors .eq { color: var(--p-lav); }
.affil {
  margin-top: 10px;
  font-size: 14px;
  color: var(--ink-faint);
}
.footer-actions { display: flex; gap: 14px; margin: 30px 0 44px; flex-wrap: wrap; }
.btn-ghost {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 20px;
  border-radius: 999px;
  border: 1px solid var(--line-strong);
  color: var(--p-pale);
  font-size: 14px;
  font-weight: 600;
  background: transparent;
  cursor: pointer;
  font-family: var(--font-body);
  transition: border-color .25s ease, color .25s ease, background .25s ease;
}
.btn-ghost:hover { border-color: var(--p-lav); color: #fff; background: rgba(83, 74, 209, 0.14); }
.bib-wrap {
  position: relative;
  max-width: 860px;
}
.bib-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 10px;
}
.bib-head h4 {
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-dim);
}
.bib-wrap pre {
  background: #0A0C18;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 20px 22px;
  font-size: 13px;
  line-height: 1.65;
  color: #C7C9E6;
  overflow-x: auto;
  font-family: ui-monospace, 'SF Mono', Menlo, Consolas, monospace;
}
.copyright {
  margin-top: 44px;
  font-size: 13px;
  color: var(--ink-faint);
}

/* ---------------- Lightbox ---------------- */

.lightbox {
  position: fixed;
  inset: 0;
  z-index: 200;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 4vh 4vw;
  background: rgba(7, 8, 18, 0.88);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}
.lightbox.open { display: flex; }
.lb-panel {
  width: min(1240px, 100%);
  max-height: 92vh;
  display: flex;
  flex-direction: column;
}
.lb-panel video {
  width: 100%;
  max-height: 76vh;
  border-radius: 14px;
  background: #000;
  border: 1px solid var(--line-strong);
  box-shadow: 0 30px 100px rgba(0, 0, 0, 0.7);
}
.lb-meta { padding: 16px 4px 0; display: flex; align-items: baseline; gap: 14px; flex-wrap: wrap; }
.lb-meta .lb-title {
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 600;
}
.lb-meta .lb-note { font-size: 14px; color: var(--ink-dim); }
.lb-prompt {
  margin: 12px 4px 0;
  padding: 12px 16px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: rgba(13, 15, 30, 0.55);
  max-height: 18vh;
  overflow-y: auto;
}
.lb-prompt .p-label {
  display: block;
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--p-lav);
  margin-bottom: 5px;
}
.lb-prompt p { font-size: 13px; line-height: 1.6; color: #CFD2EC; }
.lb-close {
  position: absolute;
  top: 22px;
  right: 26px;
  width: 42px;
  height: 42px;
  border-radius: 50%;
  border: 1px solid rgba(255, 255, 255, 0.25);
  background: rgba(13, 15, 30, 0.6);
  color: #fff;
  font-size: 20px;
  line-height: 1;
  cursor: pointer;
  transition: background .2s ease, border-color .2s ease;
}
.lb-close:hover { background: rgba(83, 74, 209, 0.5); border-color: var(--p-lav); }

/* ---------------- Reveal ---------------- */

.reveal {
  opacity: 0;
  transform: translateY(26px);
  transition: opacity .7s cubic-bezier(.2, .6, .2, 1), transform .7s cubic-bezier(.2, .6, .2, 1);
}
.reveal.in { opacity: 1; transform: none; }

/* ============================================================
   Touch layer — phones & tablets have no hover, so the prompt
   veil becomes tap-to-toggle (.veil-on set by site.js) and all
   tap targets grow to >= 44px.
   ============================================================ */

@media (hover: none) {
  .vcard, .longrow .frame, .expand-btn, .btn-paper, .btn-ghost, .nav a, .lb-close {
    -webkit-tap-highlight-color: transparent;
  }
  .expand-btn { width: 44px; height: 44px; }
  .expand-btn svg { width: 17px; height: 17px; }
  /* keep the duration badge clear of the larger expand button */
  .dur-badge { right: 68px; }
  .prompt-veil { padding-right: 62px; }
  .badge-return { bottom: 46px; }
  /* tap-toggled prompt veil (mirrors the desktop hover reveal) */
  .vcard.veil-on { border-color: var(--line-strong); }
  .vcard.veil-on .prompt-veil,
  .longrow .frame.veil-on .prompt-veil { opacity: 1; }
  .vcard.veil-on .traj-chip,
  .longrow .frame.veil-on .hero-tag,
  .longrow .frame.veil-on .dur-badge { opacity: 0; }
  .vcard.veil-on .badge-return { opacity: 1; transform: translateY(0); }
  /* badge cards: keep the prompt clear of the start-return pill */
  .vcard:has(.badge-return) .prompt-veil p { -webkit-line-clamp: 3; }
  .lb-close {
    width: 46px;
    height: 46px;
    top: calc(10px + env(safe-area-inset-top, 0px));
    right: calc(12px + env(safe-area-inset-right, 0px));
  }
}

/* ============================================================
   Mobile layer — layout comfort on small screens.
   All rules live at the end of the file so they win the cascade;
   nothing here applies above 820px, so desktop is untouched.
   ============================================================ */

@media (max-width: 820px) {
  section {
    padding: 76px max(20px, env(safe-area-inset-right, 0px)) 30px max(20px, env(safe-area-inset-left, 0px));
  }
  section:first-of-type { padding-top: 62px; }
  .section-head { margin-bottom: 32px; }
  .content { border-radius: 18px 18px 0 0; }
  /* legibility floor: nothing under 13px on small screens */
  .eyebrow { font-size: 13px; }
  .scroll-cue { font-size: 13px; }
  .vcard .caption .motion { font-size: 13px; letter-spacing: 0.1em; }
  .badge-return { font-size: 13px; }
  .traj-chip { font-size: 13px; }
  .dur-badge { font-size: 13px; }
  .hero-tag { font-size: 13px; letter-spacing: 0.1em; }
  .prompt-veil .p-label { font-size: 13px; letter-spacing: 0.18em; }
  .lb-prompt .p-label { font-size: 13px; letter-spacing: 0.18em; }
  .lb-prompt p { font-size: 14px; }
  .vcard .caption .name { font-size: 16px; }
  /* long-horizon rows */
  .longrow .meta { padding-top: 13px; }
  .longrow .title { font-size: 19px; }
  /* footer */
  .footer {
    padding: 56px max(20px, env(safe-area-inset-right, 0px)) 40px max(20px, env(safe-area-inset-left, 0px));
  }
  .footer-logo img { height: 38px; }
  .authors { font-size: 15.5px; }
  .bib-wrap pre { padding: 16px 18px; -webkit-overflow-scrolling: touch; }
}

/* method figure: keep the diagram legible — horizontal pan instead of shrinking */
@media (max-width: 700px) {
  .method-figure { padding: 14px 14px 16px; border-radius: 16px; }
  .fig-scroll {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    border-radius: 6px;
    scrollbar-width: thin;
  }
  .fig-scroll img { width: 700px; min-width: 700px; max-width: none; }
  .fig-hint {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 7px;
    margin-top: 12px;
    font-size: 13px;
    font-weight: 500;
    letter-spacing: 0.06em;
    color: var(--ink-dim);
    transition: opacity .45s ease;
  }
  .fig-hint svg { animation: hint-slide 2s ease-in-out infinite; }
  .fig-hint.seen { opacity: 0; }
  .method-figure figcaption { margin-top: 10px; }
}
@keyframes hint-slide {
  0%, 100% { transform: translateX(0); }
  50%      { transform: translateX(6px); }
}

/* hero on phones */
@media (max-width: 480px) {
  .hero-inner { padding: 0 20px; }
  .hero-title { font-size: clamp(44px, 16.9vw, 66px); margin-bottom: 20px; }
  .hero-chips { gap: 8px; margin-top: 26px; }
  .hero-chips span { padding: 6px 14px; }
  .scroll-cue { bottom: calc(20px + env(safe-area-inset-bottom, 0px)); }
  .wall { gap: 22px; }
  .long-list { gap: 34px; }
}
/* very narrow phones: keep the chip row at two lines max */
@media (max-width: 360px) {
  .hero-chips span:nth-child(2) { display: none; }
}

/* lightbox on phones */
@media (max-width: 640px) {
  .lightbox {
    padding: max(14px, env(safe-area-inset-top, 0px)) 12px max(16px, env(safe-area-inset-bottom, 0px));
  }
  .lb-meta { padding-top: 12px; gap: 6px 12px; }
  .lb-meta .lb-title { font-size: 18px; }
  .lb-prompt { max-height: 26vh; }
}

/* ---------------- Reduced motion ---------------- */

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .scroll-cue svg { animation: none; }
  .fig-hint svg { animation: none; }
  .vcard, .mcard, .btn-paper { transition: none; }
  .hero-media { will-change: auto; }
  .hero-inner::before { animation: none; opacity: 0.85; }
  .hero-title, .hero-tagline, .hero-sub, .hero-chips { animation: none; }
}