* { box-sizing: border-box; }

:root {
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;

  --bg-1: #07111f;
  --bg-2: #0d1b33;
  --bg-3: #132848;

  --panel: rgba(14, 25, 46, 0.88);
  --panel-strong: rgba(18, 32, 58, 0.96);
  --panel-soft: rgba(255, 255, 255, 0.05);

  --border: rgba(185, 210, 255, 0.16);
  --border-strong: rgba(205, 225, 255, 0.25);

  --text: #f7fbff;
  --muted: #bfd0ea;
  --muted-2: #93a8c8;

  --accent: #dfeeff;
  --accent-2: #b5d4ff;
  --accent-3: #8ebaf7;
  --accent-dark: #0b1830;

  --good: #92e0bb;
  --bad: #ffb2b2;

  --shadow: 0 18px 50px rgba(0, 0, 0, 0.35);
}

html, body {
  margin: 0;
  min-height: 100%;
  color: var(--text);
  background:
    radial-gradient(circle at top, rgba(120, 170, 255, 0.18) 0, transparent 28rem),
    radial-gradient(circle at 85% 15%, rgba(255, 255, 255, 0.08) 0, transparent 14rem),
    linear-gradient(180deg, var(--bg-2) 0%, var(--bg-1) 48%, #050c18 100%);
}

body {
  position: relative;
  overflow-x: hidden;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  opacity: 0.45;
  background-image:
    radial-gradient(circle at 12% 18%, rgba(255,255,255,0.85) 0 1px, transparent 2px),
    radial-gradient(circle at 28% 34%, rgba(255,255,255,0.55) 0 1px, transparent 2px),
    radial-gradient(circle at 82% 12%, rgba(255,255,255,0.8) 0 1px, transparent 2px),
    radial-gradient(circle at 72% 28%, rgba(255,255,255,0.55) 0 1px, transparent 2px),
    radial-gradient(circle at 18% 72%, rgba(255,255,255,0.65) 0 1px, transparent 2px),
    radial-gradient(circle at 88% 78%, rgba(255,255,255,0.75) 0 1px, transparent 2px),
    radial-gradient(circle at 58% 84%, rgba(255,255,255,0.55) 0 1px, transparent 2px);
  background-repeat: no-repeat;
}

button,
select,
input {
  font: inherit;
}

button {
  cursor: pointer;
}

button:disabled {
  cursor: not-allowed;
  opacity: 0.55;
}

.app {
  width: min(980px, calc(100% - 28px));
  margin: 0 auto;
  padding: 30px 0 56px;
  position: relative;
  z-index: 1;
}

.topbar {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 24px;
}

.eyebrow {
  margin: 0 0 6px;
  color: var(--accent-2);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.3em;
  text-transform: uppercase;
}

h1, h2, h3, p {
  margin-top: 0;
}

h1 {
  margin-bottom: 0;
  font-size: clamp(2.1rem, 5vw, 3.4rem);
  line-height: 1.02;
  letter-spacing: -0.03em;
}

h2 {
  font-size: 1.8rem;
  margin-bottom: 10px;
}

h3 {
  font-size: 1.25rem;
  margin-bottom: 14px;
}

.scorebox {
  text-align: right;
  white-space: nowrap;
  color: var(--muted);
  font-size: 1rem;
}

.scorebox span,
.scorebox strong {
  display: block;
}

.scorebox strong {
  margin-top: 4px;
  color: var(--text);
  font-size: 1.05rem;
}

.panel {
  background: linear-gradient(180deg, rgba(19, 34, 61, 0.95), rgba(10, 19, 35, 0.95));
  border: 1px solid var(--border);
  border-radius: 24px;
  padding: clamp(20px, 4vw, 32px);
  box-shadow: var(--shadow);
  backdrop-filter: blur(8px);
}

.settings {
  display: flex;
  flex-wrap: wrap;
  align-items: end;
  gap: 18px 20px;
  margin: 24px 0;
}

.settings label:not(.check) {
  display: grid;
  gap: 8px;
  color: var(--muted);
  font-size: 0.95rem;
}

select {
  min-width: 140px;
  background: rgba(255, 255, 255, 0.06);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 12px 14px;
  outline: none;
}

select:focus {
  border-color: var(--accent-3);
  box-shadow: 0 0 0 3px rgba(142, 186, 247, 0.18);
}

.check {
  display: flex;
  align-items: center;
  gap: 10px;
  min-height: 46px;
  color: var(--muted);
}

.check input {
  width: 18px;
  height: 18px;
  accent-color: var(--accent-3);
}

.primary,
.secondary {
  min-height: 48px;
  border-radius: 14px;
  padding: 11px 18px;
  font-weight: 800;
  border: 1px solid transparent;
  transition: transform 0.15s ease, opacity 0.15s ease, border-color 0.15s ease, background 0.15s ease;
}

.primary:hover,
.secondary:hover {
  transform: translateY(-1px);
}

.primary {
  background: linear-gradient(180deg, var(--accent) 0%, var(--accent-2) 100%);
  color: var(--accent-dark);
  box-shadow: 0 10px 24px rgba(111, 163, 240, 0.18);
}

.secondary {
  background: rgba(255, 255, 255, 0.04);
  color: var(--text);
  border-color: var(--border);
}

.help {
  margin-top: 22px;
  color: var(--muted);
  font-size: 0.95rem;
}

.help summary {
  cursor: pointer;
  color: var(--text);
}

.help p {
  margin: 10px 0 0;
}

code {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border);
  padding: 2px 6px;
  border-radius: 7px;
  color: var(--accent);
}

.quiz {
  display: grid;
  gap: 18px;
}

.photo-wrap {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  background:
    linear-gradient(180deg, rgba(255,255,255,0.02), rgba(255,255,255,0.01)),
    rgba(4, 10, 19, 0.9);
  border: 1px solid var(--border);
  border-radius: 24px;
  overflow: hidden;
  min-height: 320px;
  box-shadow: var(--shadow);
}

.photo-wrap img {
  display: block;
  max-width: 100%;
  width: auto;
  max-height: 72vh;
  object-fit: contain;
}

.image-error {
  padding: 60px 20px;
  color: var(--bad);
  text-align: center;
}

.feedback {
  min-height: 28px;
  text-align: center;
  font-weight: 800;
  font-size: 1.08rem;
}

.feedback.correct {
  color: var(--good);
}

.feedback.wrong {
  color: var(--bad);
}

.answers {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 10px;
}

.answer {
  min-height: 54px;
  padding: 12px;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: linear-gradient(180deg, rgba(255,255,255,0.05), rgba(255,255,255,0.025));
  color: var(--text);
  font-weight: 750;
}

.answer:hover {
  border-color: var(--border-strong);
  background: linear-gradient(180deg, rgba(255,255,255,0.08), rgba(255,255,255,0.035));
}

.answer.correct {
  border-color: rgba(146, 224, 187, 0.7);
  background: rgba(146, 224, 187, 0.14);
}

.answer.wrong {
  border-color: rgba(255, 178, 178, 0.75);
  background: rgba(255, 178, 178, 0.14);
}

.answer:disabled {
  opacity: 1;
  cursor: default;
}

#nextBtn {
  justify-self: center;
  min-width: 150px;
}

.result-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

.mistakes-wrap {
  margin-top: 28px;
}

.mistakes {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.mistake {
  overflow: hidden;
  border-radius: 16px;
  border: 1px solid var(--border);
  background: linear-gradient(180deg, rgba(255,255,255,0.05), rgba(255,255,255,0.03));
}

.mistake img {
  display: block;
  width: 100%;
  aspect-ratio: 1 / 1;
  object-fit: cover;
  background: #08101d;
}

.mistake div {
  padding: 12px;
  font-size: 0.92rem;
}

.mistake strong {
  display: block;
  color: var(--accent);
  margin-bottom: 4px;
}

.mistake span {
  color: var(--muted);
}

.hidden {
  display: none !important;
}

/* Tablet / smaller laptop */
@media (max-width: 820px) {
  .answers {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .mistakes {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

/* Phone */
@media (max-width: 600px) {
  .app {
    width: min(100% - 16px, 980px);
    padding-top: 16px;
    padding-bottom: 28px;
  }

  .topbar {
    display: block;
  }

  .scorebox {
    text-align: left;
    margin-top: 14px;
  }

  .panel {
    border-radius: 20px;
    padding: 18px;
  }

  .settings {
    display: grid;
    gap: 14px;
  }

  .settings label:not(.check) {
    width: 100%;
  }

  select {
    width: 100%;
  }

  .check {
    align-items: flex-start;
  }

  .photo-wrap {
    min-height: 220px;
    border-radius: 20px;
  }

  .photo-wrap img {
    max-height: 52vh;
  }

  .answers {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .result-actions {
    display: grid;
    grid-template-columns: 1fr;
  }

  .result-actions button {
    width: 100%;
  }
}

/* Very small phones */
@media (max-width: 420px) {
  h1 {
    font-size: 2rem;
  }

  .answers {
    grid-template-columns: 1fr;
  }

  .mistakes {
    grid-template-columns: 1fr;
  }

  .answer {
    min-height: 50px;
  }
}