/* ============================================================
   Fish3R — project page (dark, point-cloud aesthetic)
   ============================================================ */
:root {
  --bg: #0b0e17;
  --bg-alt: #0e1220;
  --panel: #12172a;
  --line: rgba(148, 163, 216, .14);
  --ink: #e9ecf7;
  --muted: #9aa3c0;
  --faint: #6b7494;
  --cyan: #22d3ee;
  --violet: #818cf8;
  --radius: 16px;
  --font-display: "Sora", "Inter", system-ui, sans-serif;
  --font-body: "Inter", system-ui, -apple-system, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, monospace;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font-body);
  background: var(--bg); color: var(--ink);
  line-height: 1.65; font-size: 16px;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
img { max-width: 100%; display: block; }
.wrap-wide { max-width: 1120px; margin: 0 auto; padding: 0 28px; }

/* ---------------- Hero ---------------- */
.hero {
  position: relative; min-height: 100svh;
  display: grid; place-items: center;
  text-align: center; padding: 96px 24px 72px;
  overflow: hidden;
  background:
    radial-gradient(1100px 560px at 50% -8%, rgba(129, 140, 248, .16), transparent 62%),
    radial-gradient(900px 500px at 82% 108%, rgba(34, 211, 238, .10), transparent 60%),
    var(--bg);
}
#stars { position: absolute; inset: 0; width: 100%; height: 100%; }
.hero-inner { position: relative; z-index: 1; max-width: 860px; }

.badges { display: flex; flex-wrap: wrap; gap: 8px; justify-content: center; margin-bottom: 30px; }
.badge {
  font-size: 12px; font-weight: 600; letter-spacing: .4px;
  color: var(--muted);
  border: 1px solid var(--line);
  background: rgba(18, 23, 42, .6);
  padding: 5px 13px; border-radius: 999px;
  backdrop-filter: blur(6px);
}
.badge.solid {
  color: #06222a; background: var(--cyan); border-color: var(--cyan);
  box-shadow: 0 0 24px rgba(34, 211, 238, .35);
}

.title {
  font-family: var(--font-display);
  font-size: clamp(58px, 11vw, 108px);
  font-weight: 800; letter-spacing: -3px; line-height: 1;
  background: linear-gradient(115deg, #f2f5ff 20%, var(--violet) 60%, var(--cyan) 95%);
  -webkit-background-clip: text; background-clip: text; color: transparent;
  filter: drop-shadow(0 0 34px rgba(129, 140, 248, .35));
}
.subtitle {
  margin-top: 18px;
  font-family: var(--font-display);
  font-size: clamp(17px, 2.6vw, 25px); font-weight: 600; line-height: 1.45;
  color: var(--ink);
}
.tagline { margin-top: 16px; font-size: 15.5px; color: var(--muted); }
.tagline em { color: var(--cyan); font-style: normal; font-weight: 600; }

.btns { margin-top: 32px; display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 14px; font-weight: 600;
  padding: 11px 20px; border-radius: 11px;
  color: var(--ink);
  background: rgba(18, 23, 42, .75);
  border: 1px solid var(--line);
  backdrop-filter: blur(6px);
}
.btn.disabled { color: var(--faint); border-style: dashed; cursor: default; }

.scroll-cue {
  display: inline-grid; place-items: center;
  margin-top: 56px; width: 40px; height: 40px; border-radius: 50%;
  color: var(--muted); border: 1px solid var(--line);
  animation: bob 2.2s ease-in-out infinite;
}
.scroll-cue:hover { color: var(--cyan); text-decoration: none; }
@keyframes bob { 0%,100% { transform: translateY(0); } 50% { transform: translateY(7px); } }

/* ---------------- Fisheye strip ---------------- */
.strip { padding: 56px 0 64px; background: var(--bg-alt); border-block: 1px solid var(--line); }
.strip-label {
  text-align: center; color: var(--faint);
  font-size: 14.5px; letter-spacing: .3px; margin-bottom: 30px; padding: 0 24px;
}
.strip-label strong { color: var(--ink); font-weight: 600; }
.marquee {
  overflow: hidden;
  mask-image: linear-gradient(90deg, transparent, #000 10%, #000 90%, transparent);
  -webkit-mask-image: linear-gradient(90deg, transparent, #000 10%, #000 90%, transparent);
}
.marquee-track {
  display: flex; gap: 26px; width: max-content;
  animation: slide var(--slide-dur, 36s) linear infinite;
}
.marquee:hover .marquee-track { animation-play-state: paused; }
@keyframes slide { to { transform: translateX(-50%); } }
.feye {
  position: relative; flex: none;
  width: 168px; height: 168px; border-radius: 50%;
  overflow: hidden;
  border: 1px solid rgba(148, 163, 216, .3);
  box-shadow: 0 0 0 6px rgba(18, 23, 42, .9), 0 0 30px rgba(34, 211, 238, .12);
}
.feye img { width: 100%; height: 100%; object-fit: cover; }
.feye figcaption {
  position: absolute; inset: auto 0 10px 0;
  text-align: center; font-size: 11px; font-weight: 600; letter-spacing: .5px;
  color: #eaf6ff; text-shadow: 0 1px 6px rgba(0,0,0,.9);
}
@media (max-width: 560px) { .feye { width: 128px; height: 128px; } }

/* ---------------- Sections ---------------- */
.section { padding: 88px 0; }
.section.alt { background: var(--bg-alt); border-block: 1px solid var(--line); }

.sec-head { margin-bottom: 40px; }
.kicker {
  display: inline-block;
  font-family: var(--font-mono); font-size: 12.5px; font-weight: 500;
  letter-spacing: 3px; text-transform: uppercase;
  color: var(--cyan);
  padding: 5px 14px; border: 1px solid rgba(34, 211, 238, .3); border-radius: 999px;
  background: rgba(34, 211, 238, .07);
  margin-bottom: 18px;
}
.sec-head h2 {
  font-family: var(--font-display);
  font-size: clamp(26px, 4vw, 40px); font-weight: 700; letter-spacing: -1px; line-height: 1.2;
}

/* figure cards (white figures on dark page) */
.fig-card {
  position: relative;
  background: #fff; border-radius: 18px;
  padding: 14px;
  margin-bottom: 44px;
  border: 1px solid rgba(148, 163, 216, .28);
  box-shadow:
    0 0 0 1px rgba(34, 211, 238, .12),
    0 0 44px rgba(34, 211, 238, .07),
    0 22px 60px rgba(0, 0, 0, .55);
}
/* gradient edge: lets the white card melt softly into the dark page */
.fig-card::after {
  content: ""; position: absolute; inset: -1px; border-radius: 18px;
  padding: 1px; pointer-events: none;
  background: linear-gradient(140deg, rgba(34, 211, 238, .55), rgba(148, 163, 216, .12) 30%, rgba(148, 163, 216, .12) 70%, rgba(129, 140, 248, .5));
  -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  -webkit-mask-composite: xor; mask-composite: exclude;
}
.fig-card img { border-radius: 10px; }
.fig-card figcaption {
  padding: 12px 6px 2px; font-size: 13px; color: #4b5164; line-height: 1.55;
  border-top: 1px dashed rgba(75, 81, 100, .18); margin: 10px 6px 0;
}

/* abstract: newspaper-style two-column prose */
.prose {
  max-width: 980px; margin: 0 auto;
  columns: 2; column-gap: 44px;
  color: var(--muted); font-size: 15.5px;
}
.prose p { margin-bottom: 14px; break-inside: avoid; }
.prose p:first-child::first-letter {
  font-family: var(--font-display);
  float: left; font-size: 46px; font-weight: 800; line-height: .9;
  padding: 4px 10px 0 0; color: var(--cyan);
}
.prose strong, .prose em { color: var(--ink); }
@media (max-width: 760px) { .prose { columns: 1; } }

/* method: stepper */
.stepper {
  list-style: none;
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 0;
  counter-reset: step;
  border-top: 1px solid var(--line);
}
.step {
  position: relative; padding: 28px 22px 6px;
  border-left: 1px solid var(--line);
}
.step:first-child { border-left: none; }
.step-no {
  font-family: var(--font-mono); font-size: 13px; font-weight: 500;
  color: var(--violet); letter-spacing: 2px;
  display: block; margin-bottom: 12px;
}
.step h3 { font-family: var(--font-display); font-size: 15.5px; font-weight: 700; margin-bottom: 9px; }
.step p { font-size: 13.5px; color: var(--muted); line-height: 1.6; }
.step::before {
  content: ""; position: absolute; top: -4.5px; left: 22px;
  width: 8px; height: 8px; border-radius: 50%;
  background: var(--cyan); box-shadow: 0 0 12px rgba(34, 211, 238, .8);
}
@media (max-width: 900px) {
  .stepper { grid-template-columns: 1fr 1fr; border-top: none; }
  .step { border-left: none; border-top: 1px solid var(--line); }
  .step::before { top: -4.5px; }
}
@media (max-width: 520px) { .stepper { grid-template-columns: 1fr; } }

/* ablation: split figure + takeaway aside */
.split { display: grid; grid-template-columns: 1.65fr 1fr; gap: 34px; align-items: center; }
.split .fig-card { margin-bottom: 0; }
.aside-note { padding: 8px 4px; }
.aside-big {
  font-family: var(--font-display);
  font-size: 19px; font-weight: 600; line-height: 1.5;
  color: var(--ink); margin-bottom: 16px;
}
.aside-small { font-size: 14px; color: var(--muted); line-height: 1.65; margin-bottom: 18px; }
.aside-arrow { font-size: 30px; color: var(--cyan); line-height: 1; }
@media (max-width: 860px) { .split { grid-template-columns: 1fr; } }

/* footer */
.footer { padding: 30px 0 40px; border-top: 1px solid var(--line); }
.footer-inner { display: flex; justify-content: space-between; align-items: center; gap: 12px; flex-wrap: wrap; font-size: 13.5px; color: var(--faint); }
.footer-inner a { color: var(--muted); }