/* The small dark pages: course entry, under construction, not found. Same family as the landing page. */

:root {
  --void: #02050c; --line: rgba(127, 214, 255, .22); --line-strong: rgba(127, 214, 255, .6);
  --ice: #7fd6ff; --white: #eef8ff; --dim: rgba(190, 220, 245, .6); --warn: #ffb4a8;
  --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; min-height: 100dvh; display: grid; grid-template-rows: auto 1fr auto; color: var(--white); font-family: var(--sans);
  background:
    linear-gradient(rgba(127, 214, 255, .035) 1px, transparent 1px) 0 0 / 100% 56px,
    linear-gradient(90deg, rgba(127, 214, 255, .035) 1px, transparent 1px) 0 0 / 56px 100%,
    radial-gradient(110% 80% at 50% 38%, #0a1c3a 0%, #040b1a 48%, var(--void) 100%);
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; }

.top, .foot { padding: var(--pad); font: 500 .72rem/1.3 var(--mono); letter-spacing: .24em; text-transform: uppercase; }
.top a { text-decoration: none; }
.top a:hover, .top a:focus-visible { color: var(--ice); outline: none; }
.top i, .foot i { display: inline-block; width: 1.4em; height: 1px; margin: 0 .7em; background: currentColor; vertical-align: .32em; opacity: .7; }
.foot { color: var(--dim); font-weight: 400; font-size: .66rem; letter-spacing: .16em; }

.center { display: grid; place-items: center; padding: 0 var(--pad) var(--pad); }
.card { width: min(100%, 27rem); }
.eyebrow { margin: 0 0 .9rem; font: 500 .74rem/1 var(--mono); letter-spacing: .32em; text-transform: uppercase; color: var(--ice); }
h1 { margin: 0; font-weight: 200; font-size: clamp(2.1rem, 6vw, 3.4rem); line-height: 1.04; letter-spacing: -.015em; }
h1 strong { font-weight: 600; }
.rule { height: 1px; margin: 1.4rem 0; background: linear-gradient(90deg, var(--line-strong), rgba(127, 214, 255, 0) 90%); }
.lede { margin: 0 0 1.6rem; color: var(--dim); font-size: 1rem; line-height: 1.55; }

/* entry form */
.field { display: grid; gap: .45rem; margin-bottom: 1.05rem; }
.field label { font: 500 .68rem/1 var(--mono); letter-spacing: .24em; text-transform: uppercase; color: var(--dim); }
.field input {
  width: 100%; padding: .9rem 1rem; font: 400 1.05rem/1.2 var(--mono); letter-spacing: .04em; color: var(--white);
  background: rgba(6, 14, 30, .7); border: 1px solid var(--line); border-radius: 3px; outline: none; transition: border-color .2s ease, box-shadow .2s ease;
}
.field input:focus { border-color: var(--line-strong); box-shadow: 0 0 0 2px rgba(127, 214, 255, .25); }
.field input::placeholder { color: rgba(190, 220, 245, .3); }
.show { display: inline-flex; align-items: center; gap: .5rem; margin: -.3rem 0 1.3rem; font: 400 .7rem/1 var(--mono); letter-spacing: .14em; text-transform: uppercase; color: var(--dim); cursor: pointer; }
.show input { accent-color: var(--ice); width: 1rem; height: 1rem; margin: 0; }
.go {
  width: 100%; padding: 1rem 1.1rem; font: 600 1rem/1 var(--sans); letter-spacing: .02em; color: #02101f; cursor: pointer;
  background: var(--ice); border: 1px solid var(--ice); border-radius: 3px; transition: filter .2s ease, transform .2s ease;
}
.go:hover, .go:focus-visible { filter: brightness(1.12); outline: none; }
.go:focus-visible { box-shadow: 0 0 0 3px rgba(127, 214, 255, .4); }
.alert { margin: 0 0 1.2rem; padding: .8rem 1rem; border: 1px solid rgba(255, 180, 168, .5); border-radius: 3px; background: rgba(60, 14, 10, .45); color: var(--warn); font-size: .95rem; line-height: 1.4; }
.alert[hidden] { display: none; }
.fine { margin: 1.3rem 0 0; color: var(--dim); font-size: .84rem; line-height: 1.5; }

/* under construction */
.status { display: inline-flex; align-items: center; gap: .7rem; padding: .55rem .9rem; border: 1px solid var(--line); border-radius: 3px; font: 500 .72rem/1 var(--mono); letter-spacing: .24em; text-transform: uppercase; color: var(--ice); }
.status::before { content: ""; width: .45rem; height: .45rem; border-radius: 50%; border: 1px solid var(--ice); }
.back { display: inline-block; margin-top: 2rem; padding-bottom: .2rem; font: 500 .74rem/1 var(--mono); letter-spacing: .22em; text-transform: uppercase; text-decoration: none; color: var(--white); border-bottom: 1px solid var(--line-strong); }
.back:hover, .back:focus-visible { color: var(--ice); outline: none; }
.orbit { width: 7.5rem; height: 7.5rem; margin-bottom: 2rem; opacity: .9; }
.orbit .spin { transform-origin: 60px 60px; animation: spin 24s linear infinite; }
.orbit .spin2 { transform-origin: 60px 60px; animation: spin 38s linear infinite reverse; }
@keyframes spin { to { transform: rotate(360deg); } }
@media (prefers-reduced-motion: reduce) { .orbit .spin, .orbit .spin2 { animation: none; } }