:root {
  --bg: #0f1a2e;
  --bg-2: #15243f;
  --card: #1c2c4d;
  --card-2: #24375c;
  --text: #e6ecf5;
  --muted: #9aa8c0;
  --primary: #4f8cff;
  --primary-2: #3a73e0;
  --good: #38c172;
  --bad: #e3342f;
  --warn: #f6ad55;
  --border: #2a3e64;
  --shadow: 0 6px 24px rgba(0,0,0,.25);
  --radius: 14px;
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }
html, body { margin: 0; padding: 0; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background: linear-gradient(160deg, var(--bg) 0%, var(--bg-2) 100%);
  color: var(--text);
  min-height: 100vh;
  line-height: 1.5;
}

header {
  padding: 1.5rem 1.25rem .75rem;
  text-align: center;
  border-bottom: 1px solid var(--border);
}
header h1 { margin: 0; font-size: 1.4rem; letter-spacing: .2px; }
header .subtitle { color: var(--muted); font-size: .9rem; margin-top: .15rem; }

main {
  max-width: 880px;
  margin: 0 auto;
  padding: 1.25rem;
}

.screen { display: none; }
.screen.active { display: block; }

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.1rem 1.2rem;
  margin-bottom: 1rem;
  box-shadow: var(--shadow);
}
.card h3 { margin: 0 0 .75rem; font-size: 1rem; color: var(--muted); text-transform: uppercase; letter-spacing: .8px; }

.tabs {
  display: flex; gap: .4rem; margin-bottom: .75rem;
  flex-wrap: wrap;
}
.tab {
  background: var(--card-2);
  border: 1px solid var(--border);
  color: var(--text);
  padding: .45rem .9rem;
  border-radius: 999px;
  cursor: pointer;
  font-size: .9rem;
}
.tab.active { background: var(--primary); border-color: var(--primary); color: white; }

.panel { margin-top: .25rem; }
.chip-group { display: flex; flex-wrap: wrap; gap: .4rem; }
.chip {
  background: var(--card-2);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: .35rem .8rem;
  cursor: pointer;
  font-size: .85rem;
  user-select: none;
  display: inline-flex;
  align-items: center;
  gap: .35rem;
}
.chip:hover { border-color: var(--primary); }
.chip.selected { background: var(--primary); border-color: var(--primary); color: white; }
.chip .count { color: var(--muted); font-size: .75rem; }
.chip.selected .count { color: rgba(255,255,255,.85); }

.row { display: flex; flex-direction: column; gap: .5rem; }
.row label { display: flex; align-items: center; gap: .5rem; cursor: pointer; }
input[type="number"] {
  background: var(--card-2);
  border: 1px solid var(--border);
  color: var(--text);
  padding: .3rem .5rem;
  border-radius: 6px;
  width: 5rem;
  font-size: .95rem;
}
input[type="number"]:disabled { opacity: .5; }

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  font-size: .95rem;
}
button.primary {
  background: var(--primary);
  color: white;
  padding: .65rem 1.2rem;
  border-radius: 10px;
  font-weight: 600;
  transition: background .15s ease;
}
button.primary:hover { background: var(--primary-2); }
button.primary.big { font-size: 1.05rem; padding: .85rem 1.6rem; }
button.ghost {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text);
  padding: .45rem .9rem;
  border-radius: 8px;
}
button.ghost:hover { border-color: var(--primary); }
button:disabled { opacity: .5; cursor: not-allowed; }

.actions {
  display: flex; justify-content: space-between; align-items: center;
  gap: 1rem; margin-top: .5rem; flex-wrap: wrap;
}
.info { color: var(--muted); font-size: .9rem; }

.quiz-header { margin-bottom: 1rem; }
.progress {
  height: 6px; background: var(--card); border-radius: 4px; overflow: hidden;
  border: 1px solid var(--border);
}
#progress-bar { height: 100%; background: var(--primary); width: 0%; transition: width .25s ease; }
.meta {
  display: flex; justify-content: space-between; align-items: center;
  margin-top: .55rem; font-size: .85rem; color: var(--muted);
  gap: .5rem;
}
.meta #q-source { flex: 1; text-align: center; }

.question-card .q-title {
  font-size: 1.05rem; line-height: 1.5; margin-bottom: 1rem;
  white-space: pre-wrap;
}
#q-image-wrap {
  margin: .5rem 0 1rem;
  display: flex; flex-wrap: wrap; gap: .5rem;
}
#q-image-wrap img {
  max-width: 100%; max-height: 420px; border-radius: 10px; border: 1px solid var(--border);
  cursor: zoom-in;
  flex: 1 1 320px; object-fit: contain;
}
#q-image-wrap img.zoomed { max-height: none; flex-basis: 100%; cursor: zoom-out; }

.options { display: flex; flex-direction: column; gap: .5rem; margin: 0 0 1rem; }
.option {
  display: flex; align-items: flex-start; gap: .65rem;
  padding: .65rem .85rem;
  background: var(--card-2);
  border: 1px solid var(--border);
  border-radius: 10px;
  cursor: pointer;
}
.option:hover { border-color: var(--primary); }
.option input { margin-top: .25rem; }
.option .letter { font-weight: 700; color: var(--primary); width: 1.2rem; flex-shrink: 0; }
.option.correct { background: rgba(56,193,114,.12); border-color: var(--good); }
.option.incorrect { background: rgba(227,52,47,.12); border-color: var(--bad); }
.option.missed { background: rgba(246,173,85,.12); border-color: var(--warn); }
.option.locked { cursor: default; }
.option.locked input { pointer-events: none; }

.q-actions { display: flex; gap: .6rem; flex-wrap: wrap; }

.feedback {
  margin-top: 1rem;
  padding: .9rem 1rem;
  border-radius: 10px;
  background: var(--card-2);
  border: 1px solid var(--border);
}
.feedback.good { border-color: var(--good); }
.feedback.bad { border-color: var(--bad); }
.feedback h4 { margin: 0 0 .5rem; font-size: .95rem; }
.feedback .explanation {
  font-size: .9rem; color: var(--text);
  white-space: pre-wrap;
  max-height: 350px; overflow-y: auto;
  padding-right: .5rem;
}
.feedback .explanation table { border-collapse: collapse; margin: .5rem 0; font-size: .85rem; }
.feedback .explanation th, .feedback .explanation td {
  border: 1px solid var(--border); padding: .35rem .55rem;
}

.score-card { text-align: center; }
.score { font-size: 2.4rem; font-weight: 700; margin: .5rem 0; }
.score .pct { color: var(--primary); }

#review-list .review-item {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem 1.1rem;
  margin-bottom: .8rem;
}
.review-item.ok { border-left: 4px solid var(--good); }
.review-item.ko { border-left: 4px solid var(--bad); }
.review-item .ri-head {
  display: flex; justify-content: space-between; gap: 1rem; align-items: baseline;
  margin-bottom: .5rem;
}
.review-item .ri-head .badge {
  font-size: .75rem; padding: .15rem .5rem; border-radius: 4px;
  background: var(--card-2); color: var(--muted);
}

.q-tools {
  display: flex; gap: .4rem; margin-top: .75rem; flex-wrap: wrap;
  border-top: 1px dashed var(--border); padding-top: .75rem;
}
.q-tools button {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--muted);
  padding: .3rem .7rem;
  border-radius: 6px;
  font-size: .8rem;
}
.q-tools button:hover { color: var(--text); border-color: var(--primary); }
.edit-badge {
  display: inline-block;
  background: var(--warn);
  color: #1a1a1a;
  font-size: .7rem;
  padding: .1rem .4rem;
  border-radius: 4px;
  margin-left: .35rem;
  font-weight: 600;
}

.modal-backdrop {
  position: fixed; inset: 0;
  background: rgba(0,0,0,.65);
  display: flex; align-items: center; justify-content: center;
  z-index: 1000;
  padding: 1rem;
}
.modal {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  width: 100%; max-width: 720px;
  max-height: 92vh;
  display: flex; flex-direction: column;
  box-shadow: var(--shadow);
}
.modal-head {
  display: flex; justify-content: space-between; align-items: center;
  padding: .9rem 1.2rem;
  border-bottom: 1px solid var(--border);
}
.modal-head h3 { margin: 0; font-size: 1.05rem; }
.modal-body {
  padding: 1rem 1.2rem;
  overflow-y: auto;
  display: flex; flex-direction: column; gap: .85rem;
}
.modal-body label { font-size: .85rem; color: var(--muted); display: block; margin-bottom: .25rem; }
.modal-body input[type="text"],
.modal-body input[type="password"],
.modal-body textarea {
  width: 100%;
  background: var(--card-2);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 6px;
  padding: .55rem .7rem;
  font-family: inherit;
  font-size: .92rem;
  resize: vertical;
}
.modal-body textarea { min-height: 70px; }
.modal-body .opt-row {
  display: grid;
  grid-template-columns: 28px 1fr 24px;
  gap: .5rem; align-items: center;
}
.modal-body .opt-row .letter { font-weight: 700; color: var(--primary); }
.modal-body .opt-row input[type="checkbox"] { margin: 0; }
.modal-actions {
  display: flex; gap: .5rem; justify-content: flex-end;
  padding: .9rem 1.2rem;
  border-top: 1px solid var(--border);
  flex-wrap: wrap;
}
.modal-msg { font-size: .85rem; padding: .5rem .7rem; border-radius: 6px; }
.modal-msg.error { background: rgba(227,52,47,.15); color: #ffb1ae; border: 1px solid var(--bad); }
.modal-msg.ok { background: rgba(56,193,114,.15); color: #b6f0cf; border: 1px solid var(--good); }

footer {
  text-align: center;
  color: var(--muted);
  font-size: .8rem;
  padding: 1rem;
}

@media (max-width: 600px) {
  header h1 { font-size: 1.15rem; }
  .card { padding: .9rem; }
  main { padding: .85rem; }
}