/* pop3star.com — the first stars, for everyone */

:root {
  --bg:        #05070d;
  --bg-2:      #080c17;
  --bg-3:      #0b1120;
  --ink:       #e9edf7;
  --ink-dim:   #a4aec6;
  --ink-faint: #6f7a93;
  --rule:      rgba(255, 255, 255, 0.10);
  --rule-soft: rgba(255, 255, 255, 0.06);
  --blue:      #7cc4ff;
  --blue-hot:  #d3e6ff;
  --violet:    #a98cff;
  --ember:     #ff9a5c;
  --gold:      #f3c96b;
  --display: "Instrument Serif", Iowan Old Style, Georgia, serif;
  --sans: "Inter", system-ui, -apple-system, Segoe UI, sans-serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, monospace;
  --wrap: 1140px;
  --pad: clamp(20px, 5vw, 40px);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 400 clamp(1.02rem, 0.45vw + 0.94rem, 1.14rem)/1.68 var(--sans);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

::selection { background: rgba(124, 196, 255, 0.28); }

a { color: var(--blue); text-decoration-color: rgba(124, 196, 255, 0.35); text-underline-offset: 3px; }
a:hover { text-decoration-color: currentColor; }

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

.skip {
  position: fixed; top: 10px; left: 10px; z-index: 100;
  padding: 10px 16px; border-radius: 8px;
  background: var(--bg-3); color: var(--ink);
  transform: translateY(-160%); transition: transform .2s;
}
.skip:focus { transform: none; }

/* ── scroll progress ───────────────────────────────────────── */
.scrollbar {
  position: fixed; inset: 0 0 auto 0; height: 2px; z-index: 60;
  background: rgba(255, 255, 255, 0.05);
}
.scrollbar i {
  display: block; height: 100%; width: 0;
  background: linear-gradient(90deg, var(--violet), var(--blue));
  box-shadow: 0 0 12px rgba(124, 196, 255, 0.7);
}

/* ── top bar ───────────────────────────────────────────────── */
.topbar {
  position: fixed; inset: 2px 0 auto 0; z-index: 50;
  display: flex; align-items: center; justify-content: space-between;
  gap: 24px; padding: 14px var(--pad);
  transition: background .35s, backdrop-filter .35s, border-color .35s;
  border-bottom: 1px solid transparent;
}
.topbar.is-stuck {
  background: rgba(5, 7, 13, 0.72);
  backdrop-filter: blur(14px) saturate(140%);
  border-bottom-color: var(--rule-soft);
}
.brand {
  display: inline-flex; align-items: center; gap: 10px;
  font: 400 1.32rem/1 var(--display); letter-spacing: .01em;
  color: var(--ink); text-decoration: none;
}
.brand-dot {
  width: 9px; height: 9px; border-radius: 50%;
  background: var(--blue-hot);
  box-shadow: 0 0 10px 2px rgba(124, 196, 255, .9), 0 0 26px 6px rgba(124, 196, 255, .35);
}
.nav { display: flex; gap: clamp(14px, 2vw, 30px); }
.nav a {
  font-size: .86rem; letter-spacing: .01em; color: var(--ink-dim);
  text-decoration: none; padding: 4px 0; border-bottom: 1px solid transparent;
}
.nav a:hover, .nav a.is-active { color: var(--ink); border-bottom-color: var(--blue); }
@media (max-width: 880px) { .nav { display: none; } }

/* ── hero ──────────────────────────────────────────────────── */
.hero {
  position: relative; min-height: 100svh;
  display: grid; align-items: center;
  padding: 0 var(--pad);
  isolation: isolate;
}
.hero canvas { position: absolute; inset: 0; width: 100%; height: 100%; z-index: -2; display: block; }
.hero-veil {
  position: absolute; inset: 0; z-index: -1; pointer-events: none;
  background:
    radial-gradient(120% 80% at 72% 45%, transparent 30%, rgba(5, 7, 13, .55) 72%, var(--bg) 100%),
    linear-gradient(90deg, rgba(5, 7, 13, .85) 0%, rgba(5, 7, 13, .35) 46%, transparent 68%);
}
@media (max-width: 880px) {
  .hero-veil {
    background:
      radial-gradient(85% 34% at 66% 17%, transparent 38%, rgba(5, 7, 13, .4) 72%, var(--bg) 100%),
      linear-gradient(180deg, rgba(5, 7, 13, .1) 0%, rgba(5, 7, 13, .6) 40%, rgba(5, 7, 13, .94) 70%, var(--bg) 100%);
  }
  .hero { padding-top: 96px; align-items: end; padding-bottom: 14vh; }
}
.hero-copy { max-width: min(680px, 100%); margin-inline: auto; width: 100%; }
.hero-copy h1 {
  margin: .12em 0 .28em;
  font: 400 clamp(3.6rem, 13vw, 9.5rem)/0.92 var(--display);
  letter-spacing: -0.02em;
}
.hero-copy h1 em {
  font-style: italic;
  background: linear-gradient(100deg, var(--blue-hot), var(--blue) 45%, var(--violet));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.lede { font-size: clamp(1.1rem, 1.1vw + .9rem, 1.42rem); line-height: 1.55; color: var(--ink); max-width: 44ch; }
.hero-note { color: var(--ink-dim); font-size: .98rem; max-width: 44ch; }
.eyebrow {
  display: flex; align-items: center; gap: 12px;
  margin: 0 0 .9em;
  font: 500 .74rem/1 var(--sans); letter-spacing: .2em; text-transform: uppercase;
  color: var(--blue);
}
.eyebrow::before { content: ""; width: 34px; height: 1px; background: currentColor; opacity: .55; }

.scroll-cue {
  position: absolute; left: 50%; bottom: 34px; translate: -50% 0;
  width: 26px; height: 42px; border: 1px solid var(--rule); border-radius: 14px;
}
.scroll-cue span {
  position: absolute; left: 50%; top: 9px; translate: -50% 0;
  width: 4px; height: 8px; border-radius: 2px; background: var(--blue);
  animation: cue 1.9s ease-in-out infinite;
}
@keyframes cue { 0%, 100% { opacity: 0; transform: translateY(0); } 35% { opacity: 1; } 75% { opacity: 0; transform: translateY(13px); } }

/* ── bands ─────────────────────────────────────────────────── */
.band { position: relative; padding: clamp(86px, 11vw, 150px) var(--pad); }
.band-tight { padding-block: clamp(64px, 8vw, 104px); }
.band-dark { background: linear-gradient(180deg, var(--bg-2), var(--bg-3) 50%, var(--bg-2)); }
.band-dark::before, .band-dark::after {
  content: ""; position: absolute; inset-inline: 0; height: 1px; background: var(--rule-soft);
}
.band-dark::before { top: 0; } .band-dark::after { bottom: 0; }
.wrap { max-width: var(--wrap); margin-inline: auto; }

h2 {
  margin: 0 0 clamp(28px, 4vw, 48px);
  font: 400 clamp(2.1rem, 4.4vw, 3.5rem)/1.08 var(--display);
  letter-spacing: -0.015em; max-width: 20ch;
}
h3 { font: 500 1.08rem/1.35 var(--sans); letter-spacing: .005em; margin: 0 0 .6em; }

.cols { display: grid; grid-template-columns: minmax(0, 1.25fr) minmax(0, 1fr); gap: clamp(28px, 4vw, 64px); align-items: start; }
@media (max-width: 900px) { .cols { grid-template-columns: 1fr; } }

.prose { max-width: 62ch; }
.prose p { margin: 0 0 1.15em; color: var(--ink-dim); }
.prose p:last-child { margin-bottom: 0; }
.prose em { color: var(--ink); font-style: italic; }
.prose .big { font: 400 clamp(1.35rem, 2vw, 1.75rem)/1.4 var(--display); color: var(--ink); }
.prose .caveat {
  border-left: 2px solid rgba(169, 140, 255, .5); padding-left: 16px;
  font-size: .95rem; color: var(--ink-faint);
}
.lead-out { margin-bottom: clamp(36px, 5vw, 60px); }

.card {
  padding: 26px 28px; border: 1px solid var(--rule); border-radius: 16px;
  background: linear-gradient(180deg, rgba(255, 255, 255, .045), rgba(255, 255, 255, .012));
}
.card h3 { font-family: var(--display); font-size: 1.32rem; font-weight: 400; }
.card p { margin: 0 0 1em; color: var(--ink-dim); font-size: .96rem; }
.card-note { margin: 0 !important; color: var(--blue) !important; font-style: italic; }

.pull {
  margin: clamp(40px, 6vw, 72px) 0 0; padding-top: clamp(28px, 4vw, 40px);
  border-top: 1px solid var(--rule-soft);
  font: 400 clamp(1.4rem, 2.6vw, 2.1rem)/1.32 var(--display);
  color: var(--ink); max-width: 26ch;
}
.fig-note { margin: 14px 0 0; font-size: .84rem; line-height: 1.55; color: var(--ink-faint); }

/* ── timeline ──────────────────────────────────────────────── */
.timeline { position: relative; padding: 18px 0 0; }
.tl-track { position: relative; height: 2px; background: var(--rule); border-radius: 2px; }
.tl-fill {
  position: absolute; inset: 0 auto 0 0; width: 0;
  background: linear-gradient(90deg, rgba(169, 140, 255, .1), var(--violet) 35%, var(--blue) 70%, var(--blue-hot));
  box-shadow: 0 0 14px rgba(124, 196, 255, .55);
  transition: width 1.4s cubic-bezier(.22, .61, .36, 1);
}
.is-in .tl-fill { width: 100%; }
.tl-marks { list-style: none; margin: 0; padding: 0; position: relative; height: 140px; }
.tl-marks li {
  position: absolute; top: 0; left: var(--at); translate: -50% 0;
  width: clamp(88px, 11vw, 142px); padding-top: 22px; text-align: center;
}
.tl-marks li::before {
  content: ""; position: absolute; top: -5px; left: 50%; translate: -50% 0;
  width: 8px; height: 8px; border-radius: 50%;
  background: var(--bg); border: 1px solid var(--blue);
}
.tl-marks li:first-child { translate: 0 0; text-align: left; width: 84px; }
.tl-marks li:first-child::before { left: 4px; }
.tl-marks li:last-child { translate: -100% 0; text-align: right; }
.tl-marks li:last-child::before { left: calc(100% - 4px); }
.tl-marks b { display: block; font: 500 .84rem/1.3 var(--mono); color: var(--ink); letter-spacing: -.01em; }
.tl-marks span { display: block; margin-top: 6px; font-size: .8rem; line-height: 1.45; color: var(--ink-faint); }
.tl-key::before { background: var(--blue-hot) !important; box-shadow: 0 0 12px 3px rgba(124, 196, 255, .7); width: 11px !important; height: 11px !important; top: -6px !important; }
.tl-key b { color: var(--blue-hot); }
.tl-key span { color: var(--ink-dim); }
@media (max-width: 760px) {
  .tl-track { display: none; }
  .tl-marks { height: auto; display: grid; gap: 18px; border-left: 1px solid var(--rule); padding-left: 24px; }
  .tl-marks li {
    position: relative; inset: auto; translate: none !important;
    width: auto !important; text-align: left !important; padding-top: 0;
  }
  .tl-marks li::before { left: -28px !important; top: 6px; }
  .tl-marks li:first-child::before, .tl-marks li:last-child::before { left: -28px !important; }
}

/* ── fragmentation figure ──────────────────────────────────── */
.frag-fig { display: grid; grid-template-columns: 1fr 1fr; gap: 22px; margin: 0; }
.frag-cloud {
  position: relative; aspect-ratio: 1; border-radius: 50%;
  border: 1px solid var(--rule-soft);
  background: radial-gradient(circle at 50% 50%, rgba(124, 196, 255, .14), rgba(124, 196, 255, .03) 62%, transparent 72%);
}
.frag-enriched { background: radial-gradient(circle at 50% 50%, rgba(243, 201, 107, .13), rgba(243, 201, 107, .03) 62%, transparent 72%); }
.frag-star {
  position: absolute; width: 26%; height: 26%; border-radius: 50%;
  background: radial-gradient(circle, #fff 0%, var(--blue-hot) 38%, rgba(124, 196, 255, .25) 62%, transparent 70%);
  animation: breathe 4.5s ease-in-out infinite;
}
.frag-star.s1 { left: 26%; top: 30%; }
.frag-star.s2 { left: 50%; top: 48%; width: 18%; height: 18%; animation-delay: -2.2s; }
.frag-dot {
  position: absolute; width: 7%; height: 7%; border-radius: 50%;
  background: radial-gradient(circle, #fff, rgba(243, 201, 107, .5) 50%, transparent 72%);
  animation: breathe 5s ease-in-out infinite;
}
.frag-dot:nth-child(1)  { left: 22%; top: 34%; animation-delay: -.2s; }
.frag-dot:nth-child(2)  { left: 38%; top: 22%; animation-delay: -.7s; }
.frag-dot:nth-child(3)  { left: 58%; top: 28%; animation-delay: -1.3s; }
.frag-dot:nth-child(4)  { left: 70%; top: 44%; animation-delay: -1.8s; }
.frag-dot:nth-child(5)  { left: 30%; top: 54%; animation-delay: -2.4s; }
.frag-dot:nth-child(6)  { left: 46%; top: 44%; animation-delay: -3.0s; }
.frag-dot:nth-child(7)  { left: 60%; top: 60%; animation-delay: -3.6s; }
.frag-dot:nth-child(8)  { left: 42%; top: 68%; animation-delay: -4.1s; }
.frag-dot:nth-child(9)  { left: 26%; top: 44%; animation-delay: -1.1s; }
.frag-dot:nth-child(10) { left: 52%; top: 34%; animation-delay: -2.7s; }
.frag-dot:nth-child(11) { left: 66%; top: 34%; animation-delay: -3.3s; }
.frag-dot:nth-child(12) { left: 36%; top: 58%; animation-delay: -4.6s; }
@keyframes breathe { 0%, 100% { opacity: .55; transform: scale(.94); } 50% { opacity: 1; transform: scale(1.06); } }
.frag-fig figcaption { margin-top: 14px; font-size: .84rem; line-height: 1.5; }
.frag-fig figcaption b { display: block; color: var(--ink); font-weight: 500; font-size: .92rem; margin-bottom: 3px; }
.frag-fig figcaption span { color: var(--ink-faint); }

/* ── scale panel (3D) ──────────────────────────────────────── */
.scale-panel {
  display: grid; grid-template-columns: minmax(0, 1.25fr) minmax(0, 1fr);
  gap: clamp(24px, 3vw, 44px); align-items: stretch;
}
@media (max-width: 900px) { .scale-panel { grid-template-columns: 1fr; } }
#scale-canvas {
  width: 100%; aspect-ratio: 16 / 11; display: block;
  border: 1px solid var(--rule); border-radius: 18px;
  background-image: radial-gradient(circle at 50% 58%, rgba(124, 196, 255, .07), transparent 62%);
  background-color: #060911;
}
.scale-ui { display: flex; flex-direction: column; justify-content: center; gap: 18px; }
.slider-label { display: flex; align-items: baseline; justify-content: space-between; gap: 12px; font-size: .9rem; color: var(--ink-dim); }
.slider-label output { font: 500 1.28rem/1 var(--mono); color: var(--blue-hot); }
input[type="range"] {
  -webkit-appearance: none; appearance: none; width: 100%; height: 4px; border-radius: 4px;
  background: linear-gradient(90deg, rgba(124, 196, 255, .55), rgba(169, 140, 255, .55));
  cursor: pointer;
}
input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none; width: 20px; height: 20px; border-radius: 50%;
  background: var(--blue-hot); border: 3px solid #0a0f1c;
  box-shadow: 0 0 0 1px rgba(124, 196, 255, .6), 0 0 16px rgba(124, 196, 255, .6);
}
input[type="range"]::-moz-range-thumb {
  width: 16px; height: 16px; border-radius: 50%; background: var(--blue-hot);
  border: 3px solid #0a0f1c; box-shadow: 0 0 12px rgba(124, 196, 255, .6);
}
.chips { display: flex; flex-wrap: wrap; gap: 8px; }
.chips button {
  font: 400 .84rem/1 var(--sans); color: var(--ink-dim);
  padding: 8px 12px; border-radius: 999px; cursor: pointer;
  border: 1px solid var(--rule); background: transparent; transition: .18s;
}
.chips button:hover { color: var(--ink); border-color: rgba(124, 196, 255, .5); }
.chips button.is-on { color: #061021; background: var(--blue-hot); border-color: transparent; }
.readout { margin: 4px 0 0; display: grid; gap: 1px; background: var(--rule-soft); border: 1px solid var(--rule-soft); border-radius: 12px; overflow: hidden; }
.readout > div { display: flex; align-items: baseline; justify-content: space-between; gap: 16px; padding: 12px 16px; background: rgba(9, 13, 23, .75); }
.readout dt { font-size: .84rem; color: var(--ink-faint); }
.readout dd { margin: 0; font: 500 1rem/1 var(--mono); color: var(--ink); }

/* ── spectrum figure ───────────────────────────────────────── */
.spec-fig { margin: 0; }
#spec-canvas, #tail-canvas {
  width: 100%; aspect-ratio: 4 / 3; display: block;
  border: 1px solid var(--rule); border-radius: 16px; background: rgba(8, 11, 20, .6);
}
#tail-canvas { aspect-ratio: 5 / 4; }

/* ── fates (3D) ────────────────────────────────────────────── */
.fates { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr); gap: clamp(24px, 3vw, 48px); align-items: start; }
@media (max-width: 900px) { .fates { grid-template-columns: 1fr; } }
#fate-canvas {
  width: 100%; aspect-ratio: 1; display: block; position: sticky; top: 88px;
  border: 1px solid var(--rule); border-radius: 18px; background-color: #050810;
}
.fate-list { display: grid; gap: 10px; }
.fate-list button {
  display: block; width: 100%; text-align: left; cursor: pointer;
  padding: 18px 20px; border-radius: 14px;
  border: 1px solid var(--rule-soft); background: rgba(255, 255, 255, .018);
  color: inherit; font: inherit; transition: .22s;
}
.fate-list button:hover { border-color: rgba(124, 196, 255, .35); background: rgba(124, 196, 255, .05); }
.fate-list button[aria-selected="true"] { border-color: rgba(124, 196, 255, .6); background: rgba(124, 196, 255, .08); }
.fate-list b { font: 500 .82rem/1 var(--mono); color: var(--blue); letter-spacing: .02em; }
.fate-name { display: block; margin: 8px 0 6px; font: 400 1.32rem/1.2 var(--display); color: var(--ink); }
.fate-text { display: block; font-size: .93rem; line-height: 1.6; color: var(--ink-dim); }

/* ── legacy tiles ──────────────────────────────────────────── */
.grid-3 { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 18px; }
.tile {
  padding: 26px; border-radius: 16px; border: 1px solid var(--rule-soft);
  background: linear-gradient(180deg, rgba(255, 255, 255, .035), transparent);
  transition: border-color .25s, transform .25s;
}
.tile:hover { border-color: rgba(124, 196, 255, .35); transform: translateY(-3px); }
.tile h3 { font-family: var(--display); font-weight: 400; font-size: 1.3rem; color: var(--ink); }
.tile p { margin: 0; font-size: .95rem; color: var(--ink-dim); }

/* ── search routes ─────────────────────────────────────────── */
.routes { counter-reset: r; list-style: none; margin: 0 0 clamp(36px, 5vw, 56px); padding: 0; display: grid; gap: 1px; background: var(--rule-soft); border-block: 1px solid var(--rule-soft); }
.routes li { counter-increment: r; display: grid; grid-template-columns: 46px minmax(0, 15ch) 1fr; gap: 18px; align-items: baseline; padding: 20px 4px; background: var(--bg-3); }
.routes li::before { content: counter(r, decimal-leading-zero); font: 500 .82rem/1 var(--mono); color: var(--blue); }
.routes b { font-weight: 500; color: var(--ink); }
.routes span { color: var(--ink-dim); font-size: .95rem; }
@media (max-width: 720px) { .routes li { grid-template-columns: 34px 1fr; } .routes b { grid-column: 2; } .routes span { grid-column: 2; } }

/* ── reading ───────────────────────────────────────────────── */
.reading { list-style: none; margin: 0; padding: 0; display: grid; gap: 14px; }
.reading li { display: grid; grid-template-columns: minmax(0, 22ch) 1fr; gap: 20px; padding-bottom: 14px; border-bottom: 1px solid var(--rule-soft); }
.reading span { color: var(--ink-faint); font-size: .92rem; }
@media (max-width: 720px) { .reading li { grid-template-columns: 1fr; gap: 4px; } }

/* ── footer ────────────────────────────────────────────────── */
.footer { padding: clamp(60px, 7vw, 92px) var(--pad); border-top: 1px solid var(--rule-soft); background: var(--bg-2); }
.foot-lede { margin: 0 0 28px; font: 400 clamp(1.2rem, 2vw, 1.55rem)/1.4 var(--display); color: var(--ink); max-width: 34ch; }
.foot-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); gap: 20px; }
.foot-grid p { margin: 0; font-size: .89rem; line-height: 1.6; color: var(--ink-faint); }
.foot-grid b { color: var(--ink-dim); font-weight: 500; }

/* ── reveal on scroll ──────────────────────────────────────── */
[data-reveal] { opacity: 0; transform: translateY(22px); transition: opacity .8s cubic-bezier(.22,.61,.36,1), transform .8s cubic-bezier(.22,.61,.36,1); }
[data-reveal].is-in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  [data-reveal] { opacity: 1 !important; transform: none !important; transition: none !important; }
  .frag-star, .frag-dot, .scroll-cue span { animation: none !important; }
  .tl-fill { transition: none; }
}

/* ── legend ────────────────────────────────────────────────── */
.legend { list-style: none; margin: 0; padding: 0; display: flex; flex-wrap: wrap; gap: 8px 20px; font-size: .86rem; color: var(--ink-dim); }
.legend li { display: flex; align-items: center; gap: 9px; }
.legend i { width: 10px; height: 10px; border-radius: 50%; background: var(--c); box-shadow: 0 0 10px color-mix(in srgb, var(--c) 70%, transparent); }