:root {
  --fono: #fdf6e8;
  --karto: #ffffff;
  --inko: #2e2a24;
  --pala: #7b7268;
  --linio: #e7dcc7;
  --verda: #2f8f5b;
  --verda-fono: #e8f6ee;
  --ruĝa: #c2543c;
  --ruĝa-fono: #fbeceb;
  --akcento: #d98a2b;
}

@media (prefers-color-scheme: dark) {
  :root {
    --fono: #1e1b17;
    --karto: #2a2621;
    --inko: #f0e8db;
    --pala: #a89c8c;
    --linio: #3d372f;
    --verda: #7cd6a4;
    --verda-fono: #23382c;
    --ruĝa: #f0937c;
    --ruĝa-fono: #3a2622;
    --akcento: #e8a84e;
  }
}

* { box-sizing: border-box }

body {
  counter-reset: gxustaj;
  margin: 0;
  padding: 0 16px 96px;
  background: var(--fono);
  color: var(--inko);
  font-family: "Trebuchet MS", "Segoe UI", system-ui, sans-serif;
  font-size: 17px;
  line-height: 1.5;
}

.supro {
  max-width: 640px;
  margin: 0 auto;
  padding: 72px 0 24px;
  text-align: center;
}

.supro .signo { width: 140px; height: 140px }

.supro h1 {
  margin: 8px 0 12px;
  font-size: 34px;
  line-height: 1.15;
}

.klarigo { margin: 0 auto; max-width: 30em; color: var(--pala) }

.helpo {
  margin: 24px auto 0;
  max-width: 34em;
  padding: 12px 18px;
  border: 1px solid var(--linio);
  border-radius: 14px;
  background: var(--karto);
  text-align: left;
}

.helpo summary { cursor: pointer; font-weight: bold; color: var(--akcento) }
.helpo p { margin: 10px 0 0 }

.literoj {
  font-size: 22px;
  letter-spacing: 4px;
  user-select: all;
}

kbd {
  padding: 1px 6px;
  border: 1px solid var(--linio);
  border-bottom-width: 2px;
  border-radius: 5px;
  background: var(--fono);
  font-family: ui-monospace, "Consolas", monospace;
  font-size: 0.92em;
}

.nivelo {
  display: flex;
  flex-direction: column;
  align-items: center;
  max-width: 640px;
  margin: 28px auto;
  padding: 24px 20px 28px;
  border: 1px solid var(--linio);
  border-radius: 22px;
  background: var(--karto);
  scroll-margin-top: 72px;
}

.nivelo h2 {
  order: 1;
  margin: 0;
  font-size: 15px;
  font-weight: normal;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--pala);
}

.scenejo {
  order: 2;
  position: relative;
  width: 168px;
  height: 168px;
  margin: 4px 0 8px;
}

.scenejo img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  opacity: 0;
  transition: opacity 0.25s;
}

.scenejo .stelo {
  width: 62px;
  height: 62px;
  inset: auto -6px -6px auto;
  transform: scale(0.4);
  transition: opacity 0.35s, transform 0.35s;
}

.tasko {
  order: 3;
  margin: 0 0 4px;
  font-family: ui-monospace, "Consolas", monospace;
  font-size: 30px;
  letter-spacing: 1px;
  color: var(--pala);
}

.kampo {
  order: 4;
  width: 100%;
  max-width: 340px;
  padding: 12px 16px;
  border: 2px solid var(--linio);
  border-radius: 14px;
  background: var(--fono);
  color: var(--inko);
  font-family: inherit;
  font-size: 26px;
  text-align: center;
  transition: border-color 0.2s, background 0.2s;
}

.kampo:focus { outline: none; border-color: var(--akcento) }

.rezulto {
  order: 5;
  min-height: 1.5em;
  margin: 14px 0 0;
  text-align: center;
}

.rezulto .bone, .rezulto .ree { display: none }
.rezulto .bone { color: var(--verda) }
.rezulto .ree { color: var(--ruĝa) }

.sekva {
  order: 6;
  margin-top: 10px;
  padding: 8px 20px;
  border-radius: 999px;
  background: var(--verda-fono);
  color: var(--verda);
  font-weight: bold;
  text-decoration: none;
  opacity: 0.3;
  pointer-events: none;
  transition: opacity 0.25s;
}

.kampo:placeholder-shown ~ .scenejo .atendas { opacity: 1 }

.kampo:invalid:not(:placeholder-shown) { border-color: var(--ruĝa); background: var(--ruĝa-fono) }
.kampo:invalid:not(:placeholder-shown) ~ .scenejo .erare { opacity: 1 }
.kampo:invalid:not(:placeholder-shown) ~ .rezulto .ree { display: inline }

.kampo:valid { border-color: var(--verda); background: var(--verda-fono) }
.kampo:valid ~ .scenejo .venke { opacity: 1 }
.kampo:valid ~ .scenejo .stelo { opacity: 1; transform: scale(1) }
.kampo:valid ~ .rezulto .bone { display: inline }
.kampo:valid ~ .sekva { opacity: 1; pointer-events: auto }

.kampo:valid { counter-increment: gxustaj }

.diplomo {
  max-width: 640px;
  margin: 28px auto 0;
  padding: 28px 20px 32px;
  border: 2px dashed var(--linio);
  border-radius: 22px;
  background: var(--karto);
  text-align: center;
  opacity: 0.45;
  filter: grayscale(1);
  transition: opacity 0.4s, filter 0.4s;
  scroll-margin-top: 72px;
}

.diplomo .kato { width: 150px; height: 150px }
.diplomo h2 { margin: 4px 0 8px; font-size: 26px }
.diplomo .preta { display: none; margin: 0; color: var(--verda); font-weight: bold }
.diplomo .atendas { margin: 0; color: var(--pala) }

body:has(#k1:valid):has(#k2:valid):has(#k3:valid):has(#k4:valid):has(#k5:valid):has(#k6:valid):has(#k7:valid):has(#k8:valid):has(#k9:valid):has(#k10:valid) .diplomo { opacity: 1; filter: none; border-color: var(--verda) }
body:has(#k1:valid):has(#k2:valid):has(#k3:valid):has(#k4:valid):has(#k5:valid):has(#k6:valid):has(#k7:valid):has(#k8:valid):has(#k9:valid):has(#k10:valid) .diplomo .preta { display: block }
body:has(#k1:valid):has(#k2:valid):has(#k3:valid):has(#k4:valid):has(#k5:valid):has(#k6:valid):has(#k7:valid):has(#k8:valid):has(#k9:valid):has(#k10:valid) .diplomo .atendas { display: none }

.poentaro {
  position: fixed;
  inset: 0 0 auto 0;
  display: flex;
  gap: 10px;
  align-items: baseline;
  justify-content: center;
  padding: 12px 16px;
  border-bottom: 1px solid var(--linio);
  background: var(--karto);
  box-shadow: 0 2px 14px rgba(0, 0, 0, 0.07);
}

.poentaro .teksto { color: var(--pala); font-size: 15px }

.poentaro .nombro::after {
  content: counter(gxustaj) " / 10";
  font-size: 20px;
  font-weight: bold;
  color: var(--akcento);
}

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important }
}