* {
  box-sizing: border-box;
}

:root {
  color-scheme: dark;
}

body {
  margin: 0;
  font-family: "Inter", "SF Pro Display", "Segoe UI", sans-serif;
  background: #2b0b16;
  color: #f7f3f6;
  min-height: 100vh;
}

.topbar {
  background: #3b1020;
  border-bottom: 1px solid #4b1a2f;
  padding: 18px 0;
  text-align: center;
  text-transform: uppercase;
  letter-spacing: 6px;
  font-size: 12px;
}

.brand {
  opacity: 0.7;
}

.app {
  max-width: 1100px;
  margin: 0 auto;
  padding: 32px 24px 60px;
}

.screen {
  display: none;
}

.screen--active {
  display: block;
}

.title {
  font-size: 32px;
  font-weight: 600;
  margin-bottom: 12px;
}

.subtitle {
  color: #d9c7cf;
  margin-bottom: 32px;
}

.mode-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 18px;
}

.mode-card {
  background: #33101f;
  border: 1px solid #4b1a2f;
  border-radius: 14px;
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  text-align: left;
  color: inherit;
}

.start-actions {
  margin-top: 24px;
}

.mode-title {
  font-size: 18px;
  text-transform: uppercase;
  letter-spacing: 2px;
  color: #cfcfcf;
}

.mode-level {
  font-size: 14px;
  color: #cdbac3;
}

.mode-action {
  font-size: 12px;
  color: #f7f3f6;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.round-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 40px;
  color: #cdbac3;
  text-transform: uppercase;
  letter-spacing: 2px;
  font-size: 12px;
}

.round-meta {
  display: flex;
  gap: 16px;
}

.question-card {
  background: #33101f;
  border: 1px solid #4b1a2f;
  border-radius: 16px;
  padding: 60px 40px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 20px;
  min-height: 360px;
  justify-content: center;
  position: relative;
}

.equation {
  font-size: 96px;
  color: #f7f3f6;
  letter-spacing: 2px;
}

.answer-input {
  width: 220px;
  background: #1f0711;
  border: 1px solid #5a2236;
  border-radius: 10px;
  padding: 14px 16px;
  font-size: 40px;
  color: #ffffff;
  text-align: center;
}

.answer-input:focus {
  outline: none;
  border-color: #f7f3f6;
  box-shadow: 0 0 0 2px rgba(247, 243, 246, 0.2);
}

.btn {
  background: transparent;
  border: 1px solid #5a2236;
  color: #f7f3f6;
  padding: 10px 18px;
  border-radius: 999px;
  cursor: pointer;
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 2px;
  transition: border 0.2s ease, color 0.2s ease;
}

.btn:hover {
  border-color: #ffffff;
  color: #ffffff;
}

.btn--primary {
  background: #ffffff;
  color: #2b0b16;
  border: none;
}

.btn--primary:hover {
  color: #0b0b0b;
  filter: brightness(1.05);
}

.hint {
  color: #bfaab3;
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 2px;
}

.transfer-panel {
  margin-top: 24px;
}

.transfer-body {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.transfer-actions {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.transfer-input {
  width: 100%;
  min-height: 90px;
  background: #1f0711;
  border: 1px solid #5a2236;
  border-radius: 12px;
  padding: 12px 14px;
  color: #ffffff;
  font-size: 13px;
  font-family: "SF Mono", "Menlo", "Consolas", monospace;
  resize: vertical;
}

.transfer-input:focus {
  outline: none;
  border-color: #ffffff;
  box-shadow: 0 0 0 2px rgba(247, 243, 246, 0.2);
}

.transfer-status {
  min-height: 18px;
  font-size: 12px;
  color: #d9c7cf;
}

.transfer-status.is-error {
  color: #f5a3ad;
}

.question-card.feedback-good .equation,
.question-card.feedback-good .answer-input {
  animation: feedbackGood 450ms ease-out;
}

.question-card.feedback-neutral .equation,
.question-card.feedback-neutral .answer-input {
  animation: feedbackNeutral 450ms ease-out;
}

@keyframes feedbackGood {
  0% {
    color: #7ad06d;
    text-shadow: 0 0 16px rgba(122, 208, 109, 0.4);
  }
  60% {
    color: #7ad06d;
  }
  100% {
    color: inherit;
    text-shadow: none;
  }
}

@keyframes feedbackNeutral {
  0% {
    color: #b5b5b5;
    text-shadow: 0 0 10px rgba(180, 180, 180, 0.25);
  }
  60% {
    color: #b5b5b5;
  }
  100% {
    color: inherit;
    text-shadow: none;
  }
}

.summary-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 18px;
  margin-bottom: 32px;
}

.card {
  background: #33101f;
  border: 1px solid #4b1a2f;
  border-radius: 14px;
  padding: 22px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  min-height: 140px;
}

.card--tall {
  min-height: 220px;
}

.card-title {
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 2px;
  color: #8b8b8b;
}

.round-result {
  font-size: 42px;
  color: #ffffff;
  font-weight: 500;
}

.round-detail {
  color: #d9c7cf;
  font-size: 14px;
}

.round-tip {
  color: #f7f3f6;
  font-size: 13px;
  margin-top: auto;
}

.stat-value {
  font-size: 36px;
  color: #ffffff;
}

.stat-label {
  color: #cdbac3;
  text-transform: uppercase;
  letter-spacing: 2px;
  font-size: 12px;
}

.stat-sub {
  color: #f7f3f6;
  font-size: 12px;
}

.summary-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

@media (max-width: 720px) {
  .equation {
    font-size: 70px;
  }

  .question-card {
    padding: 40px 20px;
  }

  .answer-input {
    width: 180px;
    font-size: 32px;
  }

  .transfer-actions {
    flex-direction: column;
    align-items: stretch;
  }
}