:root {
  --bg: #dfe3fb;
  --sky-top: #c7cdf6;
  --sky-bot: #eef0fd;
  --ink: #1b2170;
  --ink-soft: #4a4f93;
  --star: #1f2585;
  --link: #7a68d8;
  --meteor: #d0467a;
  --line: #b9bff0;
  --focus: #d0467a;
  --geo: "Futura", "Century Gothic", "Avenir Next", "Trebuchet MS", "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
  --text: "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", "Helvetica Neue", Arial, sans-serif;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0e1242;
    --sky-top: #070a2e;
    --sky-bot: #1c2170;
    --ink: #eef0ff;
    --ink-soft: #b3b8e8;
    --star: #fff3c9;
    --link: #a998ff;
    --meteor: #ffb3cf;
    --line: #2c3285;
    --focus: #ffd66b;
  }
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 400 1rem/1.7 var(--text); overflow-x: hidden; }
:focus-visible { outline: 3px solid var(--focus); outline-offset: 3px; }

.top { position: absolute; z-index: 3; left: 0; right: 0; max-width: 70rem; margin: 0 auto; padding: 1.25rem 1rem; }
.brand { display: inline-flex; align-items: center; gap: .6rem; color: inherit; text-decoration: none; font-family: var(--geo); letter-spacing: .3em; font-size: .9375rem; }

.sky-wrap {
  position: relative; min-height: min(92vh, 46rem); display: flex; align-items: flex-end;
  background: linear-gradient(180deg, var(--sky-top), var(--sky-bot));
  cursor: crosshair; overflow: hidden;
}
#sky { position: absolute; inset: 0; width: 100%; height: 100%; display: block; }
.sky-copy { position: relative; z-index: 2; width: 100%; max-width: 70rem; margin: 0 auto; padding: 0 1rem 3rem; pointer-events: none; }
h1 { margin: 0 0 .75rem; font-weight: 400; }
.letters {
  display: block; font-family: var(--geo); font-weight: 500;
  font-size: clamp(1.1rem, 3vw, 1.5rem); line-height: 1.2; letter-spacing: .6em; color: var(--link);
}
.sub { display: block; font-size: clamp(1.9rem, 6vw, 3.6rem); line-height: 1.2; letter-spacing: .04em; margin-top: .5rem; font-weight: 300; }
.sky-copy p { margin: 0; color: var(--ink-soft); max-width: 30em; }

main > section:not(.sky-wrap) { max-width: 70rem; margin: 0 auto; padding: 4rem 1rem 1rem; }
h2 { font-family: var(--geo); font-weight: 500; font-size: clamp(1.5rem, 4vw, 2.2rem); margin: 0 0 .5rem; letter-spacing: .06em; }
.hint { color: var(--ink-soft); margin: 0 0 2rem; }

.words { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); gap: 0; }
.words button {
  width: 100%; font: inherit; color: inherit; background: none; cursor: pointer; text-align: left;
  border: 0; border-left: 1px solid var(--line); padding: .5rem .9rem 1rem; display: grid; gap: .15rem;
}
.words b { font-family: var(--geo); font-weight: 500; font-size: 3rem; line-height: 1.1; color: var(--link); }
.words .en { font-family: var(--geo); font-size: 1.125rem; overflow-wrap: anywhere; }
.words .zh { color: var(--ink-soft); font-size: .9375rem; }
.words button:hover b { color: var(--meteor); }
.words button.pop .en, .words button.pop .zh { animation: pop .4s ease-out; }
@keyframes pop { from { opacity: 0; transform: translateY(6px); } }

.sentence { font-size: clamp(1.15rem, 3vw, 1.5rem); margin: 2rem 0 1.25rem; max-width: 34em; min-height: 3.2em; }
.roll {
  font: inherit; font-family: var(--geo); letter-spacing: .08em; cursor: pointer;
  color: var(--bg); background: var(--ink); border: 0; border-radius: 2rem; padding: .7rem 1.6rem;
}
.roll:hover { background: var(--link); }

.facts { padding-bottom: 4rem !important; }
.facts dl { margin: 1.5rem 0 0; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 2rem; }
.facts dt { font-weight: 600; margin-bottom: .25rem; }
.facts dd { margin: 0; color: var(--ink-soft); }

.foot { border-top: 1px solid var(--line); }
.foot p { max-width: 70rem; margin: 0 auto; padding: 1.5rem 1rem 2rem; font-size: .875rem; color: var(--ink-soft); }

@media (max-width: 760px) {
  .words { grid-template-columns: 1fr; }
  .words button { border-left: 0; border-top: 1px solid var(--line); grid-template-columns: 3rem 1fr; column-gap: 1rem; align-items: center; padding: .6rem 0; }
  .words b { grid-row: span 2; font-size: 2.4rem; }
  .facts dl { grid-template-columns: 1fr; gap: 1.25rem; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition: none !important; animation: none !important; }
}