:root {
  --bg: #070b1f;
  --panel: rgba(16, 22, 58, .78);
  --panel-border: rgba(94, 234, 255, .28);
  --text: #eef3ff;
  --muted: #9aa6d6;
  --cyan: #22e3ff;
  --lime: #a3ff3c;
  --orange: #ff8a1f;
  --pink: #ff3d8b;
  --purple: #9b5cff;
  --good: #3dff8f;
  --bad: #ff4d6d;
  --radius: 20px;
  --font-display: "Segoe UI Black", "Arial Black", "Helvetica Neue", Impact, system-ui, sans-serif;
  --font: "Segoe UI", system-ui, -apple-system, Roboto, sans-serif;
  color-scheme: dark;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  color: var(--text);
  font-family: var(--font);
  -webkit-tap-highlight-color: transparent;
}

body {
  min-height: 100dvh;
  background:
    radial-gradient(ellipse at 15% 10%, rgba(155, 92, 255, .45), transparent 55%),
    radial-gradient(ellipse at 90% 30%, rgba(34, 227, 255, .28), transparent 50%),
    radial-gradient(ellipse at 50% 110%, rgba(255, 61, 139, .35), transparent 60%),
    var(--bg);
  background-attachment: fixed;
}

/* ---------- Ruimte-achtergrond ---------- */
.space { position: fixed; inset: 0; z-index: -1; overflow: hidden; pointer-events: none; }
.stars { position: absolute; inset: -100% 0 0 0; background-repeat: repeat; }
.s1 {
  background-image:
    radial-gradient(1px 1px at 20px 30px, #fff, transparent),
    radial-gradient(1px 1px at 120px 80px, #cfe8ff, transparent),
    radial-gradient(1px 1px at 200px 160px, #fff, transparent),
    radial-gradient(1px 1px at 60px 190px, #fff, transparent),
    radial-gradient(1px 1px at 170px 20px, #ffe9c4, transparent);
  background-size: 240px 220px;
  animation: fly 60s linear infinite;
  opacity: .7;
}
.s2 {
  background-image:
    radial-gradient(2px 2px at 40px 60px, #fff, transparent),
    radial-gradient(2px 2px at 260px 210px, #9ef3ff, transparent),
    radial-gradient(2px 2px at 150px 320px, #fff, transparent);
  background-size: 340px 360px;
  animation: fly 35s linear infinite, twinkle 3s ease-in-out infinite alternate;
}
.s3 {
  background-image:
    radial-gradient(3px 3px at 90px 140px, #fff, transparent),
    radial-gradient(3px 3px at 380px 40px, #ffd27a, transparent);
  background-size: 460px 520px;
  animation: fly 20s linear infinite;
}
.planet {
  position: absolute;
  width: 220px; height: 220px;
  right: -70px; bottom: 6%;
  border-radius: 50%;
  background: radial-gradient(circle at 35% 30%, #ffb36b, #ff5e3a 45%, #7a1d4f 80%);
  box-shadow: 0 0 60px rgba(255, 94, 58, .45), inset -20px -20px 40px rgba(0, 0, 0, .45);
  opacity: .85;
}
.planet::after {
  content: "";
  position: absolute;
  left: -40px; right: -40px; top: 46%;
  height: 26px;
  border-radius: 50%;
  border: 5px solid rgba(255, 210, 140, .55);
  transform: rotate(-18deg);
}
@keyframes fly { from { transform: translateY(0); } to { transform: translateY(50%); } }
@keyframes twinkle { from { opacity: .4; } to { opacity: 1; } }

@media (prefers-reduced-motion: reduce) {
  .stars { animation: none !important; }
}

/* ---------- Layout ---------- */
main {
  max-width: 560px;
  margin: 0 auto;
  padding: max(16px, env(safe-area-inset-top)) 16px max(24px, env(safe-area-inset-bottom));
  min-height: 100dvh;
}

.screen { display: none; }
.screen.active { display: block; animation: zoom-in .3s cubic-bezier(.2, 1.4, .4, 1); }
@keyframes zoom-in { from { opacity: 0; transform: scale(.94); } to { opacity: 1; transform: none; } }

.panel {
  background: var(--panel);
  border: 2px solid var(--panel-border);
  border-radius: var(--radius);
  padding: 14px 16px;
  margin: 0 0 12px;
  box-shadow: 0 0 0 1px rgba(255, 255, 255, .04) inset, 0 10px 30px rgba(0, 0, 0, .35), 0 0 24px rgba(34, 227, 255, .08);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
}
fieldset.panel { min-width: 0; }
legend {
  font-family: var(--font-display);
  text-transform: uppercase;
  letter-spacing: .06em;
  font-size: .85rem;
  color: var(--cyan);
  padding: 0 6px;
}

.title {
  font-family: var(--font-display);
  text-transform: uppercase;
  text-align: center;
  font-size: clamp(1.6rem, 7vw, 2.2rem);
  letter-spacing: .03em;
  margin: 6px 0 16px;
  background: linear-gradient(90deg, var(--cyan), var(--lime));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  filter: drop-shadow(0 0 12px rgba(34, 227, 255, .35));
}
h2 { font-family: var(--font-display); font-size: 1rem; text-transform: uppercase; letter-spacing: .04em; color: var(--orange); margin: 0 0 8px; }

/* ---------- Naam-scherm ---------- */
.hero { text-align: center; padding: 24px 0 8px; }
.rocket {
  font-size: 5rem;
  line-height: 1;
  display: inline-block;
  filter: drop-shadow(0 0 18px rgba(255, 138, 31, .7));
  animation: hover 2.4s ease-in-out infinite;
}
@keyframes hover { 0%, 100% { transform: translateY(0) rotate(-8deg); } 50% { transform: translateY(-14px) rotate(-2deg); } }
.logo {
  font-family: var(--font-display);
  font-size: clamp(2.6rem, 13vw, 4rem);
  font-style: italic;
  text-transform: uppercase;
  line-height: .95;
  margin: 12px 0 8px;
  color: #fff;
  text-shadow: 0 0 18px rgba(34, 227, 255, .6), 4px 4px 0 var(--purple);
}
.logo span { display: block; color: var(--orange); text-shadow: 0 0 18px rgba(255, 138, 31, .6), 4px 4px 0 var(--pink); }
.tagline { color: var(--muted); font-weight: 600; margin: 0 0 20px; }

.topbar { display: flex; justify-content: flex-end; }
.chip {
  font: inherit; font-weight: 700;
  color: var(--text);
  background: rgba(155, 92, 255, .25);
  border: 2px solid var(--purple);
  border-radius: 99px;
  padding: 6px 14px;
  cursor: pointer;
}

/* ---------- Formulier ---------- */
.row { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; }
.field { display: flex; flex-direction: column; gap: 4px; font-size: .85rem; font-weight: 600; color: var(--muted); }
.big-field span { font-family: var(--font-display); font-size: 1.15rem; color: var(--text); text-transform: uppercase; }
.field input {
  width: 100%;
  font: inherit;
  font-family: var(--font-display);
  font-size: 1.3rem;
  color: #fff;
  background: rgba(3, 6, 22, .7);
  border: 2px solid rgba(154, 166, 214, .3);
  border-radius: 12px;
  padding: 10px;
  text-align: center;
  transition: border-color .15s, box-shadow .15s;
}
.big-field input { font-size: 1.6rem; padding: 14px; }
.field input::placeholder { color: #4b557f; }
.field input:focus, #answer:focus { outline: none; border-color: var(--cyan); box-shadow: 0 0 0 4px rgba(34, 227, 255, .2), 0 0 18px rgba(34, 227, 255, .35); }

.ops { display: grid; grid-template-columns: repeat(4, 1fr); gap: 10px; }
.ops input { position: absolute; opacity: 0; pointer-events: none; }
.ops span {
  display: flex; align-items: center; justify-content: center;
  height: 60px;
  font-family: var(--font-display);
  font-size: 2rem;
  color: var(--muted);
  border: 2px solid rgba(154, 166, 214, .3);
  border-radius: 14px;
  background: rgba(3, 6, 22, .6);
  cursor: pointer;
  user-select: none;
  transition: transform .1s, background .15s, box-shadow .15s, color .15s;
}
.ops input:checked + span {
  color: #071018;
  background: linear-gradient(160deg, var(--lime), #39d353);
  border-color: var(--lime);
  box-shadow: 0 0 18px rgba(163, 255, 60, .55);
}
.ops input:focus-visible + span { outline: 3px solid var(--cyan); outline-offset: 2px; }
.ops span:active { transform: scale(.92); }

.example { text-align: center; color: var(--cyan); font-weight: 600; min-height: 1.4em; margin: 4px 0; }
.error { text-align: center; color: var(--bad); font-weight: 700; min-height: 1.4em; margin: 4px 0 10px; }

/* ---------- Knoppen ---------- */
.btn {
  font: inherit;
  font-family: var(--font-display);
  text-transform: uppercase;
  letter-spacing: .04em;
  border: 0;
  border-radius: 16px;
  padding: 12px 18px;
  cursor: pointer;
  transition: transform .08s, box-shadow .08s, filter .15s;
}
.btn.big { width: 100%; font-size: 1.35rem; padding: 18px; }
.btn.go {
  color: #fff;
  background: linear-gradient(180deg, #ffa53d, var(--orange) 45%, #f0441f);
  box-shadow: 0 6px 0 #a3260f, 0 10px 26px rgba(255, 110, 31, .45);
  text-shadow: 0 2px 0 rgba(0, 0, 0, .25);
}
.btn.go:hover { filter: brightness(1.08); }
.btn.go:active { transform: translateY(5px); box-shadow: 0 1px 0 #a3260f, 0 4px 12px rgba(255, 110, 31, .4); }
.btn.alt {
  width: 100%;
  color: #071018;
  background: linear-gradient(180deg, #c6ff7a, var(--lime));
  box-shadow: 0 5px 0 #4d8a12;
}
.btn.alt:active { transform: translateY(4px); box-shadow: 0 1px 0 #4d8a12; }
.btn.ghost { background: transparent; color: var(--muted); }
.icon-btn {
  font: inherit; font-size: 1.2rem; font-weight: 700;
  width: 40px; height: 40px;
  border-radius: 12px;
  color: var(--muted);
  background: rgba(255, 255, 255, .06);
  border: 2px solid rgba(154, 166, 214, .25);
  cursor: pointer;
}

/* ---------- Quiz ---------- */
.hud { display: flex; align-items: center; gap: 10px; margin-bottom: 12px; }
.progress {
  flex: 1; height: 16px;
  background: rgba(3, 6, 22, .7);
  border: 2px solid rgba(154, 166, 214, .25);
  border-radius: 99px;
  overflow: hidden;
}
.bar {
  height: 100%; width: 0;
  background: linear-gradient(90deg, var(--cyan), var(--lime));
  box-shadow: 0 0 12px var(--cyan);
  border-radius: 99px;
  transition: width .35s cubic-bezier(.2, 1.2, .4, 1);
}
.counter { font-family: var(--font-display); color: var(--muted); min-width: 56px; text-align: right; }

.stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; margin-bottom: 12px; }
.stat {
  text-align: center;
  background: var(--panel);
  border: 2px solid rgba(154, 166, 214, .2);
  border-radius: 14px;
  padding: 6px 4px;
}
.stat .label { display: block; font-size: .68rem; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; color: var(--muted); }
.stat b { font-family: var(--font-display); font-size: 1.3rem; }
.stat .ok { color: var(--good); }
.stat .nok { color: var(--bad); }
.streak.hot { border-color: var(--orange); box-shadow: 0 0 16px rgba(255, 138, 31, .55); animation: pulse .6s ease; }
@keyframes pulse { 50% { transform: scale(1.12); } }

.question { text-align: center; padding: 26px 16px 20px; border-color: rgba(34, 227, 255, .45); }
.sum {
  font-family: var(--font-display);
  font-size: clamp(2.2rem, 12vw, 3.6rem);
  margin: 4px 0 18px;
  word-break: break-word;
  color: #fff;
  text-shadow: 0 0 22px rgba(34, 227, 255, .55);
}
#answer {
  width: 100%;
  font-family: var(--font-display);
  font-size: 2.5rem;
  text-align: center;
  color: #fff;
  background: rgba(3, 6, 22, .75);
  border: 3px solid rgba(154, 166, 214, .35);
  border-radius: 16px;
  padding: 12px;
}
#answer.good { border-color: var(--good); box-shadow: 0 0 22px rgba(61, 255, 143, .5); }
#answer.bad { border-color: var(--bad); box-shadow: 0 0 22px rgba(255, 77, 109, .45); animation: shake .35s; }
@keyframes shake { 25% { transform: translateX(-8px); } 75% { transform: translateX(8px); } }

.feedback { min-height: 2.6em; font-size: 1.25rem; font-weight: 800; margin: 14px 0; display: flex; align-items: center; justify-content: center; }
.feedback.good { color: var(--lime); text-shadow: 0 0 14px rgba(163, 255, 60, .5); animation: pop .4s cubic-bezier(.2, 1.8, .4, 1); }
.feedback.bad { color: var(--bad); }
@keyframes pop { from { transform: scale(.4); opacity: 0; } to { transform: none; opacity: 1; } }

/* ---------- Quiz-modus ---------- */
.modes { grid-template-columns: 1fr 1fr; }
.modes span { font-size: 1.05rem; text-transform: uppercase; letter-spacing: .04em; }
.modes + .field { margin-top: 12px; }

.timer { display: flex; align-items: center; gap: 10px; margin: -6px 0 14px; }
.timer-track { flex: 1; height: 12px; border-radius: 99px; background: rgba(3, 6, 22, .75); border: 2px solid rgba(154, 166, 214, .25); overflow: hidden; }
.timer-bar { height: 100%; background: linear-gradient(90deg, var(--lime), var(--cyan)); transform-origin: left; }
.timer-num { font-family: var(--font-display); font-size: 1.5rem; min-width: 2ch; color: var(--cyan); }
.timer.low .timer-bar { background: linear-gradient(90deg, var(--bad), var(--orange)); }
.timer.low .timer-num { color: var(--bad); animation: pulse .5s ease infinite; }

.choices { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.choice {
  font: inherit;
  font-family: var(--font-display);
  font-size: clamp(1.4rem, 7vw, 2rem);
  color: #fff;
  padding: 18px 8px;
  border-radius: 16px;
  border: 3px solid rgba(154, 166, 214, .35);
  background: rgba(3, 6, 22, .75);
  box-shadow: 0 5px 0 rgba(0, 0, 0, .45);
  cursor: pointer;
  word-break: break-word;
  transition: transform .08s, box-shadow .08s, border-color .15s, background .15s;
}
.choice:nth-child(1) { border-color: var(--cyan); }
.choice:nth-child(2) { border-color: var(--pink); }
.choice:nth-child(3) { border-color: var(--lime); }
.choice:nth-child(4) { border-color: var(--orange); }
.choice:active:not(:disabled) { transform: translateY(4px); box-shadow: 0 1px 0 rgba(0, 0, 0, .45); }
.choice:focus-visible { outline: 3px solid #fff; outline-offset: 2px; }
.choice:disabled { cursor: default; opacity: .45; }
.choice.good { opacity: 1; color: #071018; background: linear-gradient(160deg, var(--lime), #39d353); border-color: var(--good); box-shadow: 0 0 22px rgba(61, 255, 143, .6); }
.choice.bad { opacity: 1; background: rgba(255, 77, 109, .3); border-color: var(--bad); animation: shake .35s; }

/* ---------- Resultaat ---------- */
.result { text-align: center; padding-top: 22px; }
.trophy { font-size: 4.5rem; line-height: 1; filter: drop-shadow(0 0 20px rgba(255, 210, 60, .6)); animation: hover 2.4s ease-in-out infinite; }
.rank { font-family: var(--font-display); text-transform: uppercase; color: var(--orange); font-size: 1.15rem; margin: -6px 0 6px; }
.stars-row { font-size: 2.4rem; letter-spacing: 6px; margin-bottom: 10px; }
.stars-row .off { filter: grayscale(1) brightness(.4); }
.result-stats { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.result-stats div { background: rgba(3, 6, 22, .55); border-radius: 14px; padding: 10px 6px; }
.result-stats div > b { display: block; font-family: var(--font-display); font-size: 1.7rem; color: var(--cyan); }
.result-stats span { font-size: .85rem; color: var(--muted); font-weight: 600; }
.result-stats span b { color: var(--text); }

#mistakes { list-style: none; padding: 0; margin: 0; }
#mistakes li { padding: 8px 0; border-top: 1px solid rgba(154, 166, 214, .2); font-size: 1.15rem; font-weight: 700; }
#mistakes li:first-child { border-top: 0; }
#mistakes .wrong { color: var(--bad); text-decoration: line-through; margin: 0 6px; }
#mistakes .right { color: var(--good); }
.actions { display: flex; flex-direction: column; gap: 12px; }

/* ---------- Explosie-laag ---------- */
#fireworks {
  position: fixed;
  inset: 0;
  width: 100vw;
  height: 100vh;
  pointer-events: none;
  z-index: 10;
}

@media (max-width: 380px) {
  .row { grid-template-columns: 1fr 1fr; }
  .row .field:last-child { grid-column: span 2; }
  .stat b { font-size: 1.1rem; }
}

/* ---------- App installeren ---------- */
.install-card { text-align: center; margin-top: 16px; }
.install-card p { margin: 0 0 12px; font-weight: 600; }
.install-card .install-ios { color: var(--cyan); }
.install-card .btn.ghost { margin-top: 4px; }
[hidden] { display: none !important; }