:root {
  --bg: #ffffff;
  --card: #ffffff;
  --card-2: #f7f7f5;
  --stroke: #e2e2de;
  --stroke-strong: #dddddd;
  --text: #1a1a1a;
  --muted: #6b6b68;
  --accent: #1a1a1a;
  --accent-soft: #3a3a38;
  --success: #2e7d32;
  --success-bg: #eef5ee;
  --danger: #8b3a3a;
  --danger-bg: #f5eded;
  --sans: "Roboto", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-start;
  padding: 0 1rem 1.5rem;
}

.site-header {
  align-self: stretch;
}

.mateblitz-page {
  width: 100%;
  max-width: 400px;
  display: flex;
  flex-direction: column;
  align-items: stretch;
}

.game-page__title {
  margin: 1rem 0 0.5rem;
  font-size: 1.35rem;
  font-weight: 700;
  text-align: center;
  line-height: 1.25;
  letter-spacing: -0.02em;
}

.phone {
  width: 100%;
  max-width: 400px;
  margin-top: 0.5rem;
  background: var(--card);
  border: 1px solid var(--stroke);
  border-radius: 16px;
  overflow: hidden;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
}

.game-copy {
  margin-top: 2rem;
  padding: 0 0.15rem 2rem;
  font-size: 0.95rem;
  line-height: 1.55;
}

.game-copy__lead {
  margin: 0 0 0.75rem;
  color: var(--text);
  font-size: 1rem;
  line-height: 1.5;
}

.game-copy h2 {
  margin: 1.5rem 0 0.5rem;
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--text);
}

.game-copy p {
  margin: 0 0 0.75rem;
  color: var(--muted);
}

.game-copy__links {
  margin: 0 0 0.75rem;
  padding-left: 1.15rem;
  color: var(--muted);
}

.game-copy__links li {
  margin-bottom: 0.4rem;
}

.game-copy a {
  color: var(--text);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.game-copy a:hover {
  color: var(--accent-soft);
}

.game-copy__faq {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  margin-top: 0.25rem;
}

.game-copy__faq-item {
  padding: 0.75rem 0.9rem;
  background: var(--card-2);
  border: 1px solid var(--stroke);
  border-radius: 10px;
}

.game-copy__faq-item summary {
  cursor: pointer;
  font-weight: 600;
  color: var(--text);
  font-size: 0.95rem;
}

.game-copy__faq-item p {
  margin: 0.55rem 0 0.1rem;
  color: var(--muted);
  font-size: 0.9rem;
}

@media (min-width: 640px) {
  .mateblitz-page {
    max-width: 36rem;
  }

  .phone {
    align-self: center;
  }

  .game-page__title {
    font-size: 1.5rem;
  }
}

/* Header */
.header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 1.25rem;
  border-bottom: 1px solid var(--stroke);
}

.header-status {
  font-size: 0.75rem;
  color: var(--muted);
  font-family: var(--sans);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.play-btn {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: var(--card-2);
  border: 1px solid var(--stroke);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: background 0.15s, transform 0.15s, border-color 0.15s;
  color: var(--text);
}

.play-btn:hover {
  background: #efefec;
  border-color: var(--stroke-strong);
  transform: scale(1.04);
}

.play-btn:active {
  transform: scale(0.96);
}

.play-btn svg {
  width: 16px;
  height: 16px;
}

.play-btn.is-paused {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--card-2);
}

.play-btn:disabled {
  opacity: 0.35;
  cursor: default;
  transform: none;
}

.play-btn:disabled:hover {
  background: var(--card-2);
  border-color: var(--stroke);
  transform: none;
}

/* Stat strip */
.stat-strip {
  display: flex;
  justify-content: center;
  gap: 1.75rem;
  padding: 0.875rem 1.25rem;
  border-bottom: 1px solid var(--stroke);
  font-size: 0.8125rem;
}

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

.stat-strip b {
  color: var(--text);
  font-weight: 600;
  margin-left: 0.25rem;
}

/* Ring area */
.ring-wrap {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  padding: 1.25rem 1rem 1rem;
}

.ring-core {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}

.ring-svg {
  width: 172px;
  height: 172px;
}

.ring-track {
  fill: none;
  stroke: var(--stroke);
  stroke-width: 10;
}

.ring-progress {
  fill: none;
  stroke: var(--accent);
  stroke-width: 10;
  stroke-linecap: round;
  transform-origin: 50% 50%;
  transform: rotate(-90deg);
  transition: stroke-dashoffset 0.1s linear, stroke 0.2s;
}

.ring-progress.warn {
  stroke: #666666;
}

.ring-progress.danger {
  stroke: #333333;
}

.ring-center {
  position: absolute;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.375rem;
  text-align: center;
}

.problem {
  font-family: var(--sans);
  font-size: 1.7rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text);
}

.timer {
  font-family: var(--sans);
  font-size: 0.8125rem;
  color: var(--muted);
}

.feedback {
  position: absolute;
  top: 8px;
  font-family: var(--sans);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  opacity: 0;
  transition: opacity 0.15s, transform 0.15s;
  transform: translateY(4px);
}

.feedback.show {
  opacity: 1;
  transform: translateY(0);
}

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

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

/* Metrics row */
.metrics {
  display: flex;
  border-top: 1px solid var(--stroke);
  border-bottom: 1px solid var(--stroke);
}

.metric {
  flex: 1;
  text-align: center;
  padding: 0.875rem 0.5rem;
  border-right: 1px solid var(--stroke);
}

.metric:last-child {
  border-right: none;
}

.metric-label {
  font-size: 0.6875rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  font-family: var(--sans);
  margin-bottom: 0.25rem;
}

.metric-value {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--text);
}

/* Answer grid */
.answers {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.625rem;
  padding: 0.875rem 1.25rem 0.25rem;
}

.answer-btn {
  background: var(--card);
  border: 1px solid var(--stroke);
  color: var(--text);
  font-family: var(--sans);
  font-size: 1.125rem;
  font-weight: 600;
  padding: 0.9375rem 0.625rem;
  border-radius: 12px;
  cursor: pointer;
  transition: transform 0.1s, background 0.15s, border-color 0.15s;
}

.answer-btn:hover {
  background: var(--card-2);
  border-color: var(--stroke-strong);
}

.answer-btn:active {
  transform: scale(0.97);
}

.answer-btn.correct {
  background: var(--success-bg);
  border-color: var(--success);
  color: var(--success);
}

.answer-btn.wrong {
  background: var(--danger-bg);
  border-color: var(--danger);
  color: var(--danger);
}

.answer-btn:disabled {
  cursor: default;
  opacity: 0.45;
}

.answer-btn:disabled:hover {
  background: var(--card);
  border-color: var(--stroke);
}

/* Difficulty / operator icon columns */
.icon-col {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  flex-shrink: 0;
}

.icon-col button {
  width: 38px;
  height: 38px;
  border-radius: 10px;
  background: var(--card);
  border: 1px solid var(--stroke);
  color: var(--muted);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-family: var(--sans);
  font-size: 0.6875rem;
  font-weight: 700;
  transition: background 0.15s, color 0.15s, border-color 0.15s;
}

.icon-col button svg {
  width: 16px;
  height: 14px;
}

.icon-col button.active {
  background: var(--accent);
  color: #ffffff;
  border-color: var(--accent);
}

.icon-col button:not(.active):hover {
  color: var(--text);
  border-color: var(--stroke-strong);
  background: var(--card-2);
}

.footer-space {
  height: 0.875rem;
}

@media (max-width: 380px) {
  .ring-svg {
    width: 150px;
    height: 150px;
  }

  .problem {
    font-size: 1.5rem;
  }

  .icon-col button {
    width: 34px;
    height: 34px;
  }
}