/* ==========================================================================
   IEEE / ACM Paper Writing — landing surface

   One hue carries the whole page: amber, on warm near-black by default and on
   warm off-white when the reader asks for light. Three blocks, nothing else —
   the hero (headline + guided install), the three authorities, and the
   worked audits. The hero band stays night in both themes because the shader
   behind it only exists on black.
   ========================================================================== */

:root {
  /* Night: constant across themes. The hero never inverts. */
  --night: #0b0907;
  --night-ink: #f6efe2;
  --night-ink-2: #b6aa96;
  --night-amber: #e6b264;
  --night-green: #93bf9c;
  --night-rule: rgba(246, 239, 226, 0.16);
  --night-rule-soft: rgba(246, 239, 226, 0.09);

  --serif: "Iowan Old Style", Baskerville, "Palatino Linotype", "Book Antiqua", Georgia, serif;
  --sans: "Avenir Next", Avenir, "Segoe UI", Roboto, sans-serif;
  --mono: SFMono-Regular, Consolas, "Liberation Mono", Menlo, monospace;

  --ease: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-soft: cubic-bezier(0.33, 1, 0.68, 1);

  --gutter: clamp(20px, 5vw, 72px);

  --z-sky: 0;
  --z-content: 1;
  --z-masthead: 50;
  --z-skip: 100;
}

/* Amber on warm near-black. The designed-for state. */
:root,
html[data-theme="dark"] {
  color-scheme: dark;
  --bg: #0f0c09;
  --bg-2: #171209;
  --bg-3: #201a10;
  --ink: #f4ece0;
  --ink-2: #b3a794;
  --amber: #e0a94e;
  --amber-lift: #eec177;
  --on-amber: #191207;
  --rule: rgba(244, 236, 224, 0.13);
  --rule-2: rgba(244, 236, 224, 0.26);
  --focus: #eec177;
}

/* Amber on warm off-white. */
html[data-theme="light"] {
  color-scheme: light;
  --bg: #faf6ef;
  --bg-2: #ffffff;
  --bg-3: #f1e9dc;
  --ink: #221a10;
  --ink-2: #5c5245;
  --amber: #8a6112;
  --amber-lift: #6f4d0b;
  --on-amber: #fdfaf4;
  --rule: rgba(34, 26, 16, 0.14);
  --rule-2: rgba(34, 26, 16, 0.28);
  --focus: #8a6112;
}

/* --------------------------------------------------------------------------
   Base
   -------------------------------------------------------------------------- */

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 84px;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  min-width: 320px;
  background: var(--bg);
  color: var(--ink);
  font: 400 1rem/1.62 var(--sans);
  font-kerning: normal;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; }
button { font: inherit; color: inherit; }
img { max-width: 100%; }

svg {
  width: 1.05rem;
  height: 1.05rem;
  flex: 0 0 auto;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.6;
  stroke-linecap: round;
  stroke-linejoin: round;
}
svg.glyph-solid { fill: currentColor; stroke: none; }

h1, h2, h3 {
  margin: 0;
  font-family: var(--serif);
  font-weight: 500;
  text-wrap: balance;
}
p { text-wrap: pretty; }

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

.skip-link {
  position: fixed;
  z-index: var(--z-skip);
  top: 14px;
  left: 14px;
  padding: 11px 16px;
  background: var(--amber);
  color: var(--on-amber);
  font: 600 0.78rem var(--sans);
  text-decoration: none;
  transform: translateY(-200%);
}
.skip-link:focus { transform: translateY(0); }

.deck {
  margin: 16px 0 0;
  max-width: 54ch;
  color: var(--ink-2);
  font-family: var(--serif);
  font-size: clamp(1rem, 1.15vw, 1.12rem);
  line-height: 1.58;
}

/* --------------------------------------------------------------------------
   Masthead
   -------------------------------------------------------------------------- */

.masthead {
  position: fixed;
  z-index: var(--z-masthead);
  inset: 0 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 14px var(--gutter);
  border-bottom: 1px solid transparent;
  color: var(--night-ink);
  transition: background-color 320ms var(--ease), color 320ms var(--ease),
              border-color 320ms var(--ease);
}
.masthead.is-lifted {
  background: var(--bg);
  border-bottom-color: var(--rule);
  color: var(--ink);
}

.mark {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: inherit;
  font-family: var(--serif);
  font-size: 1rem;
  letter-spacing: -0.01em;
  line-height: 1.1;
  text-decoration: none;
}
.mark img { width: 30px; height: 30px; border-radius: 7px; }

.masthead-nav { display: flex; align-items: center; gap: 6px; }

.icon-button {
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  border: 1px solid currentColor;
  border-radius: 50%;
  background: transparent;
  color: inherit;
  cursor: pointer;
  opacity: 0.6;
  transition: opacity 200ms var(--ease), color 200ms var(--ease), transform 260ms var(--ease);
}
.icon-button:hover { opacity: 1; color: var(--night-amber); transform: translateY(-1px); }
.masthead.is-lifted .icon-button:hover { color: var(--amber); }
.icon-button svg { width: 16px; height: 16px; }

.theme-toggle [data-glyph="moon"] { display: none; }
html[data-theme="dark"] .theme-toggle [data-glyph="sun"] { display: none; }
html[data-theme="dark"] .theme-toggle [data-glyph="moon"] { display: block; }

/* --------------------------------------------------------------------------
   Hero — night band, geometry shader behind it, guided install on the right
   -------------------------------------------------------------------------- */

.hero {
  position: relative;
  isolation: isolate;
  display: flex;
  align-items: flex-end;
  min-height: 100svh;
  padding: 130px var(--gutter) clamp(52px, 7vh, 88px);
  background: var(--night);
  color: var(--night-ink);
  overflow: hidden;
}

/* The poster is the ground truth: it paints before the shader boots and stays
   put if WebGL never arrives. */
.sky {
  position: absolute;
  z-index: var(--z-sky);
  inset: 0;
  background: var(--night) url("/assets/hero/sacred-strange-poster.webp") 50% 50% / cover no-repeat;
}

.sky-shader {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: 0;
  opacity: 0;
  pointer-events: none;
  transition: opacity 1100ms var(--ease-soft);
}
.sky-shader.is-live { opacity: 1; }

/* Both columns carry text, so the field is dimmed throughout and buried
   outright under the headline. */
.sky-scrim {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(95deg,
      var(--night) 0%,
      color-mix(in srgb, var(--night) 94%, transparent) 24%,
      color-mix(in srgb, var(--night) 74%, transparent) 46%,
      color-mix(in srgb, var(--night) 66%, transparent) 72%,
      color-mix(in srgb, var(--night) 52%, transparent) 100%),
    linear-gradient(to bottom,
      color-mix(in srgb, var(--night) 80%, transparent) 0%,
      transparent 22%,
      transparent 56%,
      var(--night) 96%);
}

.hero-inner {
  position: relative;
  z-index: var(--z-content);
  display: grid;
  grid-template-columns: minmax(0, 1.02fr) minmax(0, 0.98fr);
  align-items: center;
  column-gap: clamp(40px, 6vw, 88px);
  width: 100%;
}
.hero-copy { min-width: 0; }
.hero-install { min-width: 0; animation: rise 900ms var(--ease) both 560ms; }

.hero-title {
  display: grid;
  max-width: 15ch;
  margin: 0 0 0 -0.045em;
  font-size: clamp(2.8rem, 6.2vw, 5.3rem);
  line-height: 0.96;
  letter-spacing: -0.038em;
}
.hero-title span {
  display: block;
  animation: line-in 1000ms var(--ease) both;
  animation-delay: calc(120ms + var(--i) * 90ms);
}
.hero-title span:last-child { color: var(--night-amber); }

.hero-deck {
  max-width: 46ch;
  margin: 28px 0 0;
  color: var(--night-ink-2);
  font-family: var(--serif);
  font-size: clamp(1.04rem, 1.25vw, 1.2rem);
  line-height: 1.56;
  animation: rise 900ms var(--ease) both 430ms;
}

.nameplate {
  grid-column: 1 / -1;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 20px;
  margin: clamp(44px, 7vh, 76px) 0 0;
  padding-top: 18px;
  border-top: 1px solid var(--night-rule-soft);
  color: var(--night-ink-2);
  font: 400 0.7rem/1.5 var(--mono);
  letter-spacing: 0.02em;
  animation: rise 900ms var(--ease) both 650ms;
}
.nameplate span + span {
  padding-left: 20px;
  border-left: 1px solid var(--night-rule);
}
.nameplate span:first-child { color: var(--night-amber); }

/* --------------------------------------------------------------------------
   Guided installation
   -------------------------------------------------------------------------- */

.install-heading {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 24px;
  margin-bottom: 14px;
}
.install-eyebrow {
  margin: 0 0 5px;
  color: var(--night-green);
  font: 600 0.67rem/1.2 var(--sans);
  letter-spacing: 0.12em;
  text-transform: uppercase;
}
.install-heading h2 {
  color: var(--night-ink);
  font-size: clamp(1.3rem, 2vw, 1.65rem);
  line-height: 1.05;
  letter-spacing: -0.022em;
}

.agent-switch {
  display: inline-flex;
  gap: 4px;
  padding: 3px;
  border: 1px solid var(--night-rule);
  border-radius: 9px;
  background: color-mix(in srgb, var(--night) 76%, transparent);
}
.agent-choice {
  min-height: 36px;
  padding: 8px 12px;
  border: 0;
  border-radius: 6px;
  background: transparent;
  color: var(--night-ink-2);
  cursor: pointer;
  font: 600 0.72rem/1 var(--sans);
  transition: background-color 180ms var(--ease), color 180ms var(--ease);
}
.agent-choice:hover { color: var(--night-ink); }
.agent-choice.is-active {
  background: var(--night-ink);
  color: var(--night);
}

.command-row {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: 14px;
  padding: 15px 15px 15px 20px;
  border: 1px solid var(--night-rule);
  border-radius: 12px;
  background: color-mix(in srgb, var(--night) 88%, transparent);
}
.install-command-row { align-items: start; }
.install-command-row .prompt { padding-top: 8px; }
.install-command-row .copy { align-self: center; }
.command-row .prompt {
  color: var(--night-green);
  font: 400 0.92rem/1 var(--mono);
}
.command-row code {
  padding-block: 3px;
  color: var(--night-ink);
  font: 400 0.84rem/1.6 var(--mono);
  overflow-wrap: anywhere;
  white-space: pre-wrap;
}
.copy {
  min-height: 36px;
  padding: 8px 15px;
  border: 0;
  border-radius: 7px;
  background: color-mix(in srgb, var(--night-ink) 13%, transparent);
  color: var(--night-ink-2);
  cursor: pointer;
  font: 600 0.68rem/1 var(--sans);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  transition: background-color 200ms var(--ease), color 200ms var(--ease);
}
.copy:hover { background: color-mix(in srgb, var(--night-ink) 24%, transparent); color: var(--night-ink); }
.copy.is-done { color: var(--night-green); }

.install-guidance {
  margin: 10px 0 0;
  padding-left: 2px;
  color: var(--night-ink-2);
  font: 400 0.76rem/1.55 var(--sans);
}

.first-run {
  margin-top: 22px;
  padding-top: 18px;
  border-top: 1px solid var(--night-rule-soft);
}
.first-run-heading {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 18px;
}
.first-run-heading .install-eyebrow { margin: 0; }
.first-run-heading span {
  color: var(--night-ink-2);
  font: 400 0.72rem/1.4 var(--serif);
}
.first-prompt-row {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: 14px;
  margin-top: 9px;
  padding: 10px 0 9px;
  border-bottom: 1px solid var(--night-rule);
}
.chat-mark {
  color: var(--night-amber);
  font: 500 1.25rem/1 var(--serif);
}
.first-prompt-row code {
  color: var(--night-ink);
  font: 400 0.78rem/1.55 var(--mono);
  overflow-wrap: anywhere;
}
.copy-secondary {
  min-height: 32px;
  padding: 7px 10px;
  background: transparent;
}

.install-links {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 10px;
  margin: 14px 0 0;
  color: var(--night-ink-2);
  font: 500 0.7rem/1.5 var(--sans);
}
.install-links a {
  text-decoration-color: color-mix(in srgb, var(--night-ink-2) 46%, transparent);
  text-underline-offset: 3px;
}
.install-links a:hover { color: var(--night-ink); }

.copy-status {
  display: block;
  min-height: 1.4em;
  margin: 7px 0 0;
  color: var(--night-amber);
  font: 500 0.7rem/1.4 var(--sans);
}

/* --------------------------------------------------------------------------
   Three authorities
   -------------------------------------------------------------------------- */

.authorities {
  padding: clamp(80px, 12vh, 148px) var(--gutter) clamp(64px, 9vh, 110px);
}
.authorities h2 {
  max-width: 24ch;
  font-size: clamp(1.9rem, 3.4vw, 2.9rem);
  line-height: 1.04;
  letter-spacing: -0.032em;
}

.authority-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(28px, 4vw, 56px);
  margin: clamp(40px, 5vw, 62px) 0 0;
  padding: 0;
  list-style: none;
}
.authority-list li { border-top: 1px solid var(--rule-2); padding-top: 20px; }
.authority-list h3 {
  font-size: 1.16rem;
  font-weight: 600;
  letter-spacing: -0.012em;
}
.authority-list p {
  max-width: 44ch;
  margin: 10px 0 0;
  color: var(--ink-2);
  font-size: 0.93rem;
  line-height: 1.6;
}

.authorities-note {
  max-width: 72ch;
  margin: clamp(40px, 5vw, 60px) 0 0;
  padding-top: 22px;
  border-top: 1px solid var(--rule);
  color: var(--ink-2);
  font-family: var(--serif);
  font-size: 0.98rem;
  line-height: 1.62;
}

/* --------------------------------------------------------------------------
   Worked examples
   -------------------------------------------------------------------------- */

.examples {
  padding: 0 var(--gutter) clamp(80px, 12vh, 148px);
}
.examples-head h2 {
  max-width: 26ch;
  font-size: clamp(1.9rem, 3.4vw, 2.9rem);
  line-height: 1.04;
  letter-spacing: -0.032em;
}

.switcher {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  margin-top: clamp(36px, 5vw, 56px);
  border: 1px solid var(--rule-2);
  border-radius: 12px;
  overflow: hidden;
}

.example-choice {
  display: grid;
  gap: 6px;
  padding: 20px 22px 22px;
  border: 0;
  border-right: 1px solid var(--rule);
  background: transparent;
  color: var(--ink-2);
  text-align: left;
  cursor: pointer;
  transition: background-color 240ms var(--ease), color 240ms var(--ease);
}
.example-choice:last-child { border-right: 0; }
.example-choice:hover { background: var(--bg-3); color: var(--ink); }
.example-choice.is-active {
  background: var(--bg-2);
  color: var(--ink);
  box-shadow: inset 0 2px 0 var(--amber);
}
.example-choice strong {
  font-family: var(--serif);
  font-size: 1.06rem;
  font-weight: 600;
  line-height: 1.25;
}
.example-choice small { color: var(--ink-2); font-size: 0.79rem; line-height: 1.4; }

.viewer {
  margin-top: 18px;
  border: 1px solid var(--rule-2);
  border-radius: 12px;
  background: var(--bg-2);
  overflow: hidden;
}
.viewer-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 8px 10px 8px 20px;
  border-bottom: 1px solid var(--rule);
}
.viewer-file { color: var(--ink-2); font: 400 0.68rem/1.4 var(--mono); }
.viewer-actions { display: flex; align-items: center; gap: 2px; }
.viewer-actions a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 36px;
  padding: 9px 14px;
  border-radius: 7px;
  color: var(--ink-2);
  font: 600 0.69rem/1 var(--sans);
  letter-spacing: 0.06em;
  text-decoration: none;
  text-transform: uppercase;
  transition: background-color 200ms var(--ease), color 200ms var(--ease);
}
.viewer-actions a:hover { background: var(--bg-3); color: var(--ink); }
.viewer-actions svg { width: 0.8rem; height: 0.8rem; }
.viewer-actions .viewer-open { background: var(--amber); color: var(--on-amber); }
.viewer-actions .viewer-open:hover { background: var(--amber-lift); color: var(--on-amber); }

.viewer iframe {
  display: block;
  width: 100%;
  height: min(740px, 72svh);
  border: 0;
  background: var(--bg-2);
}

/* --------------------------------------------------------------------------
   Colophon
   -------------------------------------------------------------------------- */

.colophon {
  padding: 13px var(--gutter) 15px;
  background: var(--night);
  color: var(--night-ink-2);
  text-align: center;
}
.colophon p { margin: 0; }
.colophon-line {
  display: flex;
  justify-content: center;
  gap: 0.6em;
  font-family: var(--serif);
  font-size: 0.8rem;
}
.colophon a { text-decoration-color: var(--night-rule); text-underline-offset: 0.22em; }
.colophon a:hover { color: var(--night-amber); }

/* --------------------------------------------------------------------------
   Motion
   -------------------------------------------------------------------------- */

@keyframes line-in {
  from { opacity: 0; transform: translateY(0.42em); clip-path: inset(0 0 100% 0); }
  to   { opacity: 1; transform: translateY(0);      clip-path: inset(0 0 -14% 0); }
}
@keyframes rise {
  from { opacity: 0; transform: translateY(16px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* --------------------------------------------------------------------------
   Responsive
   -------------------------------------------------------------------------- */

@media (max-width: 1000px) {
  .hero { align-items: center; padding-top: 116px; }
  .hero-inner { grid-template-columns: 1fr; row-gap: clamp(38px, 6vh, 60px); }
  .authority-list { grid-template-columns: 1fr; gap: 0; }
  .authority-list li { padding: 20px 0; border-top: 1px solid var(--rule); }
  .authority-list li:first-child { border-top-color: var(--rule-2); }
  .authority-list p { max-width: 62ch; }
}

@media (max-width: 720px) {
  html { scroll-padding-top: 72px; }
  .mark span { display: none; }
  .hero { min-height: 92svh; padding-bottom: 42px; }
  .sky { background-position: 50% 30%; }
  .sky-scrim {
    background:
      linear-gradient(to bottom,
        color-mix(in srgb, var(--night) 80%, transparent) 0%,
        color-mix(in srgb, var(--night) 36%, transparent) 22%,
        color-mix(in srgb, var(--night) 84%, transparent) 50%,
        var(--night) 84%);
  }
  .hero-title { font-size: clamp(2.4rem, 10.6vw, 3.4rem); }
  .hero-deck { font-size: 1.02rem; }
  .nameplate { gap: 6px 14px; font-size: 0.64rem; }
  .nameplate span + span { padding-left: 14px; }
  .install-heading { align-items: flex-start; flex-direction: column; gap: 14px; }
  .command-row { grid-template-columns: auto minmax(0, 1fr); padding: 14px 14px 14px 16px; gap: 10px; }
  .command-row .copy { grid-column: 1 / -1; width: 100%; }
  .first-run-heading { align-items: flex-start; flex-direction: column; gap: 4px; }
  .first-prompt-row { grid-template-columns: auto minmax(0, 1fr); }
  .first-prompt-row .copy { grid-column: 1 / -1; width: 100%; }
  .install-links { align-items: flex-start; flex-direction: column; }
  .install-links span { display: none; }
  .switcher { grid-template-columns: 1fr; }
  .example-choice { border-right: 0; border-bottom: 1px solid var(--rule); }
  .example-choice:last-child { border-bottom: 0; }
  .example-choice.is-active { box-shadow: inset 2px 0 0 var(--amber); }
  .viewer-bar { flex-direction: column; align-items: stretch; gap: 10px; padding: 14px; }
  .viewer-actions { display: grid; grid-template-columns: 1fr 1fr; gap: 6px; }
  .viewer-actions a { justify-content: center; border: 1px solid var(--rule); }
  .viewer-actions .viewer-open { grid-column: 1 / -1; border-color: var(--amber); }
  .viewer iframe { height: 620px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 1ms !important;
    animation-delay: 0ms !important;
    transition-duration: 1ms !important;
  }
  .icon-button:hover { transform: none; }
}