body {
  margin: 0;
  background: #f3f6f8;
  color: #172b3f;
  font-family: Arial, Helvetica, sans-serif;
}
.player-shell {
  width: min(860px, calc(100% - 24px));
  margin: 0 auto;
  padding-bottom: 28px;
}
.player-top {
  position: sticky;
  top: 0;
  z-index: 10;
  height: 54px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: rgba(255, 255, 255, 0.97);
  box-shadow: 0 1px 10px rgba(30, 55, 75, 0.07);
}
.brand {
  display: flex;
  align-items: center;
  gap: 7px;
  color: #173968;
  text-decoration: none;
  font-weight: 800;
  font-size: 15px;
}
.top-actions {
  display: flex;
  align-items: center;
  gap: 6px;
}
.ghost {
  height: 32px;
  border: 0;
  background: #eef3f6;
  border-radius: 9px;
  padding: 0 10px;
  color: #294967;
  font-weight: 700;
  font-size: 12px;
}
.ghost.link {
  display: inline-flex;
  align-items: center;
  text-decoration: none;
}
.state-card {
  margin-top: 16px;
  padding: 20px;
  border-radius: 14px;
  background: #fff;
  box-shadow: 0 6px 20px rgba(30, 55, 75, 0.06);
}
.skill-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin: 16px 0 8px;
}
.skill-head h1 {
  margin: 0;
  font-size: 20px;
}
.skill-head .muted {
  margin: 3px 0 0;
  color: #667b8c;
  font-size: 12px;
}
.how-button {
  height: 34px;
  border: 0;
  background: #e8f2f4;
  border-radius: 9px;
  padding: 0 11px;
  color: #173968;
  font-weight: 800;
  font-size: 12px;
}
.progress-wrap {
  margin-bottom: 10px;
}
.progress-line {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 10px;
  font-size: 11px;
  color: #607588;
  font-weight: 700;
}
.progress-track {
  height: 5px;
  margin-top: 5px;
  overflow: hidden;
  border-radius: 99px;
  background: #dce4ea;
}
.progress-track span {
  display: block;
  height: 100%;
  border-radius: inherit;
  background: #16838d;
}
.question-card {
  display: flex;
  flex-direction: column;
  align-items: stretch;
  padding: 24px 26px 22px;
  border-radius: 18px;
  background: #fff;
  box-shadow: 0 10px 30px rgba(30, 55, 75, 0.08);
}
.question-card h2 {
  margin: 0 0 14px;
  text-align: center;
  font-size: 28px;
  line-height: 1.2;
  color: #17324d;
}
.visual-stage {
  display: grid;
  place-items: center;
  width: min(100%, 620px);
  margin: 0 auto 10px;
  padding: 10px;
  border-radius: 14px;
  background: #f7fafc;
}
.visual-stage:empty,
.visual-stage:has(svg > rect:first-child + line:last-child) {
  display: none;
}
.visual-stage svg {
  width: 100%;
  height: auto;
  max-height: 280px;
}
.visual-stage {
  overflow: hidden;
}
.visual-stage > img.question-raster {
  display: block;
  width: 100%;
  max-width: 620px;
  height: auto;
  max-height: 360px;
  object-fit: contain;
}
.science-illustration {
  display: block;
  width: auto;
  max-width: 100%;
  height: auto;
  max-height: 310px;
  object-fit: contain;
  border-radius: 12px;
}
.answer-area {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 10px;
  width: min(100%, 620px);
  margin: 0 auto;
  padding: 10px 12px 4px;
}
.choice-grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
}
.choice-button,
.order-button {
  min-width: 118px;
  height: 54px;
  border: 2px solid #d4dee6;
  background: #fff;
  border-radius: 12px;
  font-size: 19px;
  font-weight: 800;
  color: #17324d;
  cursor: pointer;
  box-shadow: 0 2px 8px rgba(30, 55, 75, 0.04);
  transition:
    transform 0.12s ease,
    box-shadow 0.12s ease,
    border-color 0.12s ease,
    background 0.12s ease;
}
.choice-button:hover,
.order-button:hover {
  transform: translateY(-2px);
  background: #f6fafc;
  border-color: #7fa9c5;
  box-shadow: 0 6px 14px rgba(30, 55, 75, 0.09);
}
.choice-button:active,
.order-button:active {
  transform: translateY(0);
}
.choice-button[aria-pressed="true"],
.order-button.selected {
  border-color: #1769aa;
  background: #dceeff;
  color: #0f4f82;
  box-shadow:
    0 0 0 3px rgba(23, 105, 170, 0.12),
    0 5px 14px rgba(30, 55, 75, 0.1);
}
.choice-button:focus-visible,
.order-button:focus-visible,
.primary:focus-visible,
.secondary-action:focus-visible {
  outline: 3px solid rgba(23, 105, 170, 0.28);
  outline-offset: 2px;
}
.numeric-input {
  width: 190px;
  height: 50px;
  border: 2px solid #c6d3dd;
  border-radius: 10px;
  padding: 0 12px;
  font-size: 20px;
  font-weight: 800;
  text-align: center;
}
.numeric-input:focus {
  border-color: #1769aa;
  outline: 3px solid rgba(23, 105, 170, 0.12);
}
.answer-hint {
  margin: 0;
  color: #526b7e;
  font-size: 15px;
  font-weight: 700;
  text-align: center;
}
.order-current {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px;
  min-height: 42px;
  min-width: 260px;
  align-items: center;
  padding: 8px 12px;
  border: 2px dashed #b8cbd9;
  border-radius: 10px;
  background: #f4f7f9;
}
.order-label {
  color: #294967;
  font-size: 14px;
}
.order-placeholder {
  color: #718697;
  font-size: 14px;
}
.order-chip {
  padding: 7px 10px;
  border-radius: 8px;
  background: #dceeff;
  color: #0f4f82;
  font-weight: 800;
}
.clear-answer {
  border: 0;
  background: transparent;
  color: #315f84;
  padding: 5px 10px;
  font-size: 14px;
  font-weight: 700;
  text-decoration: underline;
  cursor: pointer;
}
.clear-answer:hover {
  color: #173968;
}
.clear-answer:focus-visible {
  outline: 3px solid rgba(23, 105, 170, 0.24);
  outline-offset: 2px;
  border-radius: 6px;
}
.clear-answer[hidden] {
  display: none;
}
.match-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  align-items: center;
  padding: 5px 0;
}
.match-row select {
  height: 38px;
  border: 1px solid #b8c7d2;
  border-radius: 8px;
  background: #fff;
}
.feedback {
  margin: 14px auto 0;
  width: min(100%, 620px);
  padding: 10px 12px;
  border-radius: 10px;
  font-weight: 700;
  font-size: 13px;
}
.feedback.correct {
  background: #e9f7ee;
  color: #176b38;
}
.feedback.incorrect {
  background: #fcecea;
  color: #942c23;
}
.player-message {
  min-height: 16px;
  margin: 8px 0;
  color: #9d2f25;
  text-align: center;
  font-size: 12px;
  font-weight: 700;
}
.question-actions {
  display: flex;
  justify-content: center;
  margin-top: 14px;
}
.primary,
.secondary-action {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 42px;
  padding: 0 18px;
  border-radius: 10px;
  font-weight: 800;
  font-size: 13px;
  cursor: pointer;
}
.primary {
  border: 0;
  background: #173968;
  color: #fff;
  text-decoration: none;
  box-shadow: 0 4px 10px rgba(23, 57, 104, 0.16);
}
.primary:hover {
  background: #12345f;
}
.secondary-action {
  border: 1px solid #bfd0dc;
  background: #fff;
  color: #173968;
}
.question-actions #nextButton {
  margin-left: 16px;
}
.question-actions #nextButton[hidden] {
  display: none !important;
}
.guide-dialog {
  width: min(900px, calc(100vw - 24px));
  max-height: calc(100vh - 24px);
  border: 0;
  border-radius: 16px;
  padding: 0;
}
.guide-dialog::backdrop {
  background: rgba(20, 31, 43, 0.38);
}
.guide-panel {
  padding: 18px;
}
.guide-head {
  display: flex;
  justify-content: space-between;
  padding-bottom: 8px;
  border-bottom: 1px solid #e3e9ee;
}
.guide-head h2 {
  margin: 0;
  font-size: 20px;
}
.close-button {
  width: 30px;
  height: 30px;
  border: 0;
  border-radius: 8px;
  background: #eef2f5;
  font-size: 18px;
}
.guide-idea {
  margin: 10px 0;
  font-size: 13px;
  line-height: 1.4;
  color: #405a70;
}
.guide-panel h3 {
  margin: 0 0 6px;
  font-size: 14px;
}
.guide-panel ol {
  margin: 0;
  padding-left: 18px;
}
.guide-panel li {
  margin: 4px 0;
  font-size: 13px;
}
.guide-visual {
  height: 220px;
  padding: 8px;
  border-radius: 12px;
  background: #f4f7f9;
}
.guide-visual svg {
  width: 100%;
  height: 100%;
}
.watchout,
.try-it {
  padding: 8px 10px;
  margin-top: 8px;
  border-radius: 10px;
  font-size: 12px;
}
.watchout {
  background: #fff6dd;
}
.try-it {
  background: #eaf6ed;
}
.watchout p,
.try-it p {
  margin: 2px 0;
}
.guide-panel > .primary {
  margin-top: 10px;
}
@media (max-width: 640px) {
  .player-shell {
    width: calc(100% - 14px);
  }
  .question-card {
    padding: 18px 12px;
  }
  .question-card h2 {
    font-size: 22px;
  }
  .visual-stage {
    margin-bottom: 6px;
  }
  .answer-area {
    padding-top: 8px;
  }
  .choice-button {
    min-width: 92px;
    height: 50px;
  }
  .question-actions {
    flex-direction: column;
    gap: 10px;
  }
  .question-actions #nextButton {
    margin-left: 0;
  }
  .primary,
  .secondary-action {
    width: 100%;
  }
}

[hidden]{display:none!important}

.progress-meta{display:flex;align-items:center;gap:14px}.active-timer{display:inline-flex;align-items:center;gap:5px;color:#173968;font-size:12px;font-weight:850}.active-timer::before{content:"";width:8px;height:8px;border-radius:50%;background:#13838d}.active-timer[data-paused="true"]{color:#718596}.active-timer[data-paused="true"]::before{background:#b8c5cd}@media(max-width:520px){.progress-meta{gap:8px}.active-timer{font-size:11px}}