:root {
  color-scheme: dark;
  font-family: "Instrument Sans", "Arial", sans-serif;
  color: #f0f3ef;
  background: #111415;
  --muted: #a7afac;
  --line: #343b3a;
  --green: #c4fa89;
}
* { box-sizing: border-box; }
body { margin: 0; }
a { color: inherit; text-underline-offset: .22em; }
a:focus-visible, button:focus-visible, input:focus-visible { outline: 2px solid var(--green); outline-offset: 4px; }
.shell { width: min(100% - 40px, 1120px); margin-inline: auto; }
.header, .footer { display: flex; justify-content: space-between; align-items: center; padding-block: 22px; }
.header { border-bottom: 1px solid var(--line); }
.mark { text-decoration: none; font-size: 1.25rem; letter-spacing: -.05em; font-weight: 900; }
.mark span, .store span { color: var(--green); }
.store, .footer { font-size: .85rem; }
.store { text-decoration: none; }
.grid { display: grid; grid-template-columns: 1.2fr minmax(0, 1fr); gap: 48px; align-items: start; padding-block: clamp(36px, 9vw, 105px); }
.intro { padding-top: clamp(0px, 4vw, 40px); }
.section-label { color: var(--green); font-size: .74rem; letter-spacing: .15em; text-transform: uppercase; }
h1 { margin: 14px 0 22px; font-size: clamp(2.6rem, 6.2vw, 5.3rem); line-height: .99; letter-spacing: -.07em; }
.intro > p:last-child { max-width: 34ch; color: var(--muted); line-height: 1.6; }
.panel { border: 1px solid var(--line); background: #181c1d; padding: clamp(18px, 5vw, 34px); }
label { display: block; font-weight: 650; font-size: .92rem; }
input:not([type=checkbox]) {
  display: block; width: 100%; padding: 13px; margin: 8px 0 19px; background: #101314; color: #f0f3ef;
  border: 1px solid #4b5553; border-radius: 0; font: 1rem ui-monospace, monospace; text-transform: uppercase;
}
.toggle { display: flex; align-items: center; gap: 8px; color: var(--muted); }
input[type=checkbox] { margin: 0; width: 17px; height: 17px; accent-color: var(--green); }
#challenge { margin-top: 18px; }
#challenge:empty { margin-top: 0; }
button { margin-top: 18px; width: 100%; min-height: 48px; padding: 10px 14px; display: flex; align-items: center; justify-content: space-between; background: var(--green); color: #111415; border: 0; font: inherit; font-weight: 750; cursor: pointer; }
button:disabled { opacity: .55; cursor: default; }
#status { margin: 0; line-height: 1.5; }
#status:not(:empty) { margin-top: 18px; border-top: 1px solid var(--line); padding-top: 14px; }
#status[data-tone="first"] { color: var(--green); }
#status[data-tone="repeat"] { color: #ffdc8b; }
#reference { color: var(--muted); font-size: .9rem; overflow-wrap: anywhere; }
#report { color: var(--green); }
.footer { border-top: 1px solid var(--line); color: var(--muted); gap: 10px; flex-wrap: wrap; }
@media (max-width: 700px) {
  .grid { grid-template-columns: 1fr; gap: 24px; }
  .intro { padding: 0; }
}