/* Landing page. Dark blues and blacks; one cold accent. */

:root {
  --void: #02050c;
  --deep: #061226;
  --line: rgba(127, 214, 255, .22);
  --line-strong: rgba(127, 214, 255, .6);
  --ice: #7fd6ff;
  --white: #eef8ff;
  --dim: rgba(190, 220, 245, .58);
  --sans: "Avenir Next", "Helvetica Neue", "Segoe UI", system-ui, -apple-system, Roboto, Arial, sans-serif;
  --mono: ui-monospace, "SF Mono", Menlo, Consolas, "Roboto Mono", "Liberation Mono", monospace;
  --pad: clamp(18px, 3.2vw, 44px);
}

* { box-sizing: border-box; }
html { background: var(--void); color-scheme: dark; }
body {
  margin: 0; min-height: 100vh; color: var(--white); font-family: var(--sans);
  background: radial-gradient(120% 90% at 62% 40%, #0a1c3a 0%, #040b1a 45%, var(--void) 100%) fixed;
  -webkit-font-smoothing: antialiased; text-rendering: optimizeLegibility;
}

#stage { position: fixed; inset: 0; width: 100%; height: 100%; display: block; opacity: 0; transition: opacity 1.4s ease; }
.live #stage { opacity: 1; }

/* The scrolling length. Only present once the picture is running. */
.track { display: none; }
.live .track { display: block; height: 380vh; }

/* ------------------------------------------------------------ words and buttons */
.overlay {
  position: relative; z-index: 2; min-height: 100vh; display: flex; flex-direction: column; justify-content: center;
  padding: calc(var(--pad) + 40px) var(--pad) calc(var(--pad) + 34px);
}
.live .overlay { position: fixed; inset: 0; min-height: 0; pointer-events: none; }
.overlay__col { width: min(100%, 34rem); }

.welcome__eyebrow {
  margin: 0 0 .9rem; font: 500 .78rem/1 var(--mono); letter-spacing: .34em; text-transform: uppercase; color: var(--ice);
}
h1 {
  margin: 0; font-weight: 200; font-size: clamp(2.5rem, 6vw, 5.1rem); line-height: 1.02; letter-spacing: -.015em;
  text-shadow: 0 0 40px rgba(2, 5, 12, .9);
}
h1 strong { display: block; font-weight: 600; letter-spacing: -.02em; }
.welcome__rule {
  height: 1px; margin-top: clamp(1.1rem, 2.4vw, 1.8rem); width: 100%;
  background: linear-gradient(90deg, var(--line-strong), rgba(127, 214, 255, 0) 85%);
  transform-origin: left center;
}

.courses { margin-top: clamp(1.3rem, 3vw, 2.2rem); display: grid; gap: .6rem; }
.courses__label { margin: 0 0 .35rem; font: 500 .72rem/1 var(--mono); letter-spacing: .3em; text-transform: uppercase; color: var(--dim); }

.course {
  position: relative; display: grid; grid-template-columns: auto 1fr auto; align-items: center; column-gap: 1rem;
  padding: 1rem 2.6rem 1rem 1.1rem; min-height: 3.6rem;
  color: var(--white); text-decoration: none; border: 1px solid var(--line); border-radius: 3px;
  background: linear-gradient(90deg, rgba(8, 20, 42, .72), rgba(6, 14, 30, .46));
  -webkit-backdrop-filter: blur(6px); backdrop-filter: blur(6px);
  transition: border-color .25s ease, background-color .25s ease, transform .25s ease;
  overflow: hidden;
}
.course::before {                      /* the light that crosses the button on hover */
  content: ""; position: absolute; inset: 0 auto 0 0; width: 40%;
  background: linear-gradient(90deg, rgba(127, 214, 255, 0), rgba(127, 214, 255, .16), rgba(127, 214, 255, 0));
  transform: translateX(-120%); transition: transform .7s ease;
}
.course::after {                       /* arrow */
  content: ""; position: absolute; right: 1.1rem; top: 50%; width: .5rem; height: .5rem;
  border-top: 1.5px solid var(--ice); border-right: 1.5px solid var(--ice); transform: translateY(-50%) rotate(45deg);
  transition: transform .25s ease;
}
.course:hover, .course:focus-visible { border-color: var(--line-strong); outline: none; }
.course:focus-visible { box-shadow: 0 0 0 2px rgba(127, 214, 255, .5); }
.course:hover::before, .course:focus-visible::before { transform: translateX(260%); }
.course:hover::after, .course:focus-visible::after { transform: translate(.25rem, -50%) rotate(45deg); }
.course__n { font: 500 .74rem/1 var(--mono); letter-spacing: .1em; color: var(--ice); }
.course__t { font-size: clamp(1.02rem, 1.5vw, 1.2rem); font-weight: 500; letter-spacing: .005em; }
.course__s { font: 400 .68rem/1.2 var(--mono); letter-spacing: .12em; text-transform: uppercase; color: var(--dim); text-align: right; }
.course--open { border-color: rgba(127, 214, 255, .45); }
.course--open .course__s { color: var(--ice); }
.course--open .course__s::before {
  content: ""; display: inline-block; width: .42rem; height: .42rem; margin-right: .55rem; border-radius: 50%;
  background: var(--ice); box-shadow: 0 0 10px var(--ice); vertical-align: .05em; animation: pulse 2.4s ease-in-out infinite;
}
@keyframes pulse { 50% { opacity: .35; } }

.sig {
  position: absolute; left: var(--pad); right: var(--pad); bottom: var(--pad);
  font: 400 .68rem/1.3 var(--mono); letter-spacing: .16em; text-transform: uppercase; color: var(--dim);
}
.sig i, .hud__brand i { display: inline-block; width: 1.4em; height: 1px; margin: 0 .7em; background: currentColor; vertical-align: .32em; opacity: .7; }

/* ------------------------------------------------------------ instrument readouts */
.hud { display: none; }
.live .hud { display: block; position: fixed; inset: 0; z-index: 1; pointer-events: none; font-family: var(--mono); }
.hud__brand {
  position: absolute; top: var(--pad); left: var(--pad); font-size: .72rem; font-weight: 500; letter-spacing: .26em; text-transform: uppercase; color: var(--white);
}
.axis {
  position: absolute; left: 0; top: 0; width: 1.5rem; height: 1.5rem; margin: -.75rem 0 0 -.75rem; display: grid; place-items: center;
  font-size: .66rem; font-weight: 500; letter-spacing: 0; color: var(--ice); border: 1px solid var(--line); border-radius: 50%;
  background: rgba(2, 5, 12, .5); will-change: transform, opacity;
}
.hud__read { position: absolute; left: var(--pad); bottom: calc(var(--pad) + 2.2rem); margin: 0; display: grid; gap: .5rem; }
.hud__read div { display: grid; grid-template-columns: 11.5em auto; align-items: baseline; }
.hud__read dt { font-size: .62rem; letter-spacing: .2em; text-transform: uppercase; color: var(--dim); }
.hud__read dd { margin: 0; font-size: .74rem; letter-spacing: .08em; color: var(--white); font-variant-numeric: tabular-nums; }
.hud__eeg { position: absolute; right: var(--pad); bottom: calc(var(--pad) + 2.2rem); display: grid; grid-template-columns: auto 220px; align-items: stretch; column-gap: .6rem; }
.hud__eeg canvas { grid-column: 2; grid-row: 1; width: 220px; height: 84px; display: block; border-left: 1px solid var(--line); }
.hud__eeg ul { grid-column: 1; grid-row: 1; list-style: none; margin: 0; padding: 0; display: grid; grid-template-rows: repeat(4, 1fr); align-items: center; font-size: .58rem; letter-spacing: .1em; color: var(--dim); }
.hud__cue {
  position: absolute; left: 50%; bottom: calc(var(--pad) + .2rem); transform: translateX(-50%); display: grid; justify-items: center; gap: .6rem;
  font-size: .64rem; letter-spacing: .4em; text-indent: .4em; text-transform: uppercase; color: var(--white);
}
.hud__cue span { width: 1px; height: 2.6rem; background: linear-gradient(var(--ice), rgba(127, 214, 255, 0)); animation: cue 2.2s ease-in-out infinite; transform-origin: top; }
@keyframes cue { 0% { transform: scaleY(0); opacity: 0; } 35% { transform: scaleY(1); opacity: 1; } 100% { transform: scaleY(1) translateY(1.2rem); opacity: 0; } }

/* Once the picture runs, the script fades these in as the page scrolls. */
.live .welcome, .live .courses__label, .live .course, .live .sig { opacity: 0; will-change: opacity, transform; }
.live .course.is-on { pointer-events: auto; }

/* ------------------------------------------------------------ phones */
@media (max-width: 760px), (max-aspect-ratio: 1/1) {
  .overlay { justify-content: flex-end; padding-bottom: calc(var(--pad) + 2.6rem); }
  .overlay__col { width: 100%; }
  h1 { font-size: clamp(2.2rem, 10.5vw, 3.4rem); }
  .course { padding: .85rem 2.3rem .85rem .9rem; min-height: 3.3rem; column-gap: .75rem; }
  .course__s { display: none; }
  .course--open .course__s { display: block; font-size: 0; }
  .course--open .course__s::before { margin: 0; }
  .hud__eeg { display: none; }
  .hud__read { left: auto; right: var(--pad); top: var(--pad); bottom: auto; gap: .3rem; justify-items: end; }
  .hud__read div { grid-template-columns: auto; justify-items: end; }
  .hud__read dt { display: none; }
  .hud__read dd { font-size: .64rem; color: var(--dim); }
  .hud__brand { font-size: .62rem; letter-spacing: .2em; }
  .sig { font-size: .56rem; letter-spacing: .1em; }
  .sig i { width: .8em; margin: 0 .4em; }
}
@media (max-height: 560px) and (min-width: 761px) {
  h1 { font-size: clamp(2rem, 4.4vw, 3.2rem); }
  .course { min-height: 2.8rem; padding-block: .6rem; }
  .hud__read, .hud__eeg { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  .course--open .course__s::before, .hud__cue span { animation: none; }
  .course, .course::before, .course::after { transition: none; }
}